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.Flags.ANNOTATION;
53 import static com.sun.tools.javac.code.Flags.BLOCK;
54 import static com.sun.tools.javac.code.Kinds.*;
55 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
56 import static com.sun.tools.javac.code.TypeTags.*;
57 import static com.sun.tools.javac.code.TypeTags.WILDCARD;
58 import static com.sun.tools.javac.tree.JCTree.Tag.*;
59
60 /** This is the main context-dependent analysis phase in GJC. It
61 * encompasses name resolution, type checking and constant folding as
62 * subtasks. Some subtasks involve auxiliary classes.
63 * @see Check
64 * @see Resolve
65 * @see ConstFold
66 * @see Infer
67 *
68 * <p><b>This is NOT part of any supported API.
69 * If you write code that depends on this, you do so at your own risk.
70 * This code and its internal interfaces are subject to change or
71 * deletion without notice.</b>
72 */
73 public class Attr extends JCTree.Visitor {
74 protected static final Context.Key<Attr> attrKey =
75 new Context.Key<Attr>();
76
77 final Names names;
78 final Log log;
79 final Symtab syms;
80 final Resolve rs;
81 final Infer infer;
82 final Check chk;
83 final MemberEnter memberEnter;
84 final TreeMaker make;
85 final ConstFold cfolder;
86 final Enter enter;
87 final Target target;
88 final Types types;
89 final JCDiagnostic.Factory diags;
90 final Annotate annotate;
91 final DeferredLintHandler deferredLintHandler;
92
93 public static Attr instance(Context context) {
94 Attr instance = context.get(attrKey);
95 if (instance == null)
96 instance = new Attr(context);
97 return instance;
98 }
99
100 protected Attr(Context context) {
101 context.put(attrKey, this);
102
103 names = Names.instance(context);
104 log = Log.instance(context);
105 syms = Symtab.instance(context);
106 rs = Resolve.instance(context);
107 chk = Check.instance(context);
108 memberEnter = MemberEnter.instance(context);
109 make = TreeMaker.instance(context);
110 enter = Enter.instance(context);
111 infer = Infer.instance(context);
112 cfolder = ConstFold.instance(context);
113 target = Target.instance(context);
114 types = Types.instance(context);
115 diags = JCDiagnostic.Factory.instance(context);
116 annotate = Annotate.instance(context);
117 deferredLintHandler = DeferredLintHandler.instance(context);
118
119 Options options = Options.instance(context);
120
121 Source source = Source.instance(context);
122 allowGenerics = source.allowGenerics();
123 allowVarargs = source.allowVarargs();
124 allowEnums = source.allowEnums();
125 allowBoxing = source.allowBoxing();
126 allowCovariantReturns = source.allowCovariantReturns();
127 allowAnonOuterThis = source.allowAnonOuterThis();
128 allowStringsInSwitch = source.allowStringsInSwitch();
129 sourceName = source.name;
130 relax = (options.isSet("-retrofit") ||
131 options.isSet("-relax"));
132 findDiamonds = options.get("findDiamond") != null &&
133 source.allowDiamond();
134 useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
135 }
136
137 /** Switch: relax some constraints for retrofit mode.
138 */
139 boolean relax;
140
141 /** Switch: support generics?
142 */
143 boolean allowGenerics;
144
145 /** Switch: allow variable-arity methods.
146 */
147 boolean allowVarargs;
148
149 /** Switch: support enums?
150 */
151 boolean allowEnums;
152
153 /** Switch: support boxing and unboxing?
154 */
155 boolean allowBoxing;
156
157 /** Switch: support covariant result types?
158 */
159 boolean allowCovariantReturns;
160
161 /** Switch: allow references to surrounding object from anonymous
162 * objects during constructor call?
163 */
164 boolean allowAnonOuterThis;
165
166 /** Switch: generates a warning if diamond can be safely applied
167 * to a given new expression
168 */
169 boolean findDiamonds;
170
171 /**
172 * Internally enables/disables diamond finder feature
173 */
174 static final boolean allowDiamondFinder = true;
175
176 /**
177 * Switch: warn about use of variable before declaration?
178 * RFE: 6425594
179 */
180 boolean useBeforeDeclarationWarning;
181
182 /**
183 * Switch: allow strings in switch?
184 */
185 boolean allowStringsInSwitch;
186
187 /**
188 * Switch: name of source level; used for error reporting.
189 */
190 String sourceName;
191
192 /** Check kind and type of given tree against protokind and prototype.
193 * If check succeeds, store type in tree and return it.
194 * If check fails, store errType in tree and return it.
195 * No checks are performed if the prototype is a method type.
196 * It is not necessary in this case since we know that kind and type
197 * are correct.
198 *
199 * @param tree The tree whose kind and type is checked
200 * @param owntype The computed type of the tree
201 * @param ownkind The computed kind of the tree
202 * @param pkind The expected kind (or: protokind) of the tree
203 * @param pt The expected type (or: prototype) of the tree
204 */
205 Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
206 if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
207 if ((ownkind & ~pkind) == 0) {
208 owntype = chk.checkType(tree.pos(), owntype, pt, errKey);
209 } else {
210 log.error(tree.pos(), "unexpected.type",
211 kindNames(pkind),
212 kindName(ownkind));
213 owntype = types.createErrorType(owntype);
214 }
215 }
216 tree.type = owntype;
217 return owntype;
218 }
219
220 /** Is given blank final variable assignable, i.e. in a scope where it
221 * may be assigned to even though it is final?
222 * @param v The blank final variable.
223 * @param env The current environment.
224 */
225 boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
226 Symbol owner = env.info.scope.owner;
227 // owner refers to the innermost variable, method or
228 // initializer block declaration at this point.
229 return
230 v.owner == owner
231 ||
232 ((owner.name == names.init || // i.e. we are in a constructor
233 owner.kind == VAR || // i.e. we are in a variable initializer
234 (owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
235 &&
236 v.owner == owner.owner
237 &&
238 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
239 }
240
241 /** Check that variable can be assigned to.
242 * @param pos The current source code position.
243 * @param v The assigned varaible
244 * @param base If the variable is referred to in a Select, the part
245 * to the left of the `.', null otherwise.
246 * @param env The current environment.
247 */
248 void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
249 if ((v.flags() & FINAL) != 0 &&
250 ((v.flags() & HASINIT) != 0
251 ||
252 !((base == null ||
253 (base.hasTag(IDENT) && TreeInfo.name(base) == names._this)) &&
254 isAssignableAsBlankFinal(v, env)))) {
255 if (v.isResourceVariable()) { //TWR resource
256 log.error(pos, "try.resource.may.not.be.assigned", v);
257 } else {
258 log.error(pos, "cant.assign.val.to.final.var", v);
259 }
260 } else if ((v.flags() & EFFECTIVELY_FINAL) != 0) {
261 v.flags_field &= ~EFFECTIVELY_FINAL;
262 }
263 }
264
265 /** Does tree represent a static reference to an identifier?
266 * It is assumed that tree is either a SELECT or an IDENT.
267 * We have to weed out selects from non-type names here.
268 * @param tree The candidate tree.
269 */
270 boolean isStaticReference(JCTree tree) {
271 if (tree.hasTag(SELECT)) {
272 Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
273 if (lsym == null || lsym.kind != TYP) {
274 return false;
275 }
276 }
277 return true;
278 }
279
280 /** Is this symbol a type?
281 */
282 static boolean isType(Symbol sym) {
283 return sym != null && sym.kind == TYP;
284 }
285
286 /** The current `this' symbol.
287 * @param env The current environment.
288 */
289 Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
290 return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
291 }
292
293 /** Attribute a parsed identifier.
294 * @param tree Parsed identifier name
295 * @param topLevel The toplevel to use
296 */
297 public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
298 Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
299 localEnv.enclClass = make.ClassDef(make.Modifiers(0),
300 syms.errSymbol.name,
301 null, null, null, null);
302 localEnv.enclClass.sym = syms.errSymbol;
303 return tree.accept(identAttributer, localEnv);
304 }
305 // where
306 private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
307 private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
308 @Override
309 public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
310 Symbol site = visit(node.getExpression(), env);
311 if (site.kind == ERR)
312 return site;
313 Name name = (Name)node.getIdentifier();
314 if (site.kind == PCK) {
315 env.toplevel.packge = (PackageSymbol)site;
316 return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
317 } else {
318 env.enclClass.sym = (ClassSymbol)site;
319 return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
320 }
321 }
322
323 @Override
324 public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
325 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
326 }
327 }
328
329 public Type coerce(Type etype, Type ttype) {
330 return cfolder.coerce(etype, ttype);
331 }
332
333 public Type attribType(JCTree node, TypeSymbol sym) {
334 Env<AttrContext> env = enter.typeEnvs.get(sym);
335 Env<AttrContext> localEnv = env.dup(node, env.info.dup());
336 return attribTree(node, localEnv, Kinds.TYP, Type.noType);
337 }
338
339 public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
340 breakTree = tree;
341 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
342 try {
343 attribExpr(expr, env);
344 } catch (BreakAttr b) {
345 return b.env;
346 } catch (AssertionError ae) {
347 if (ae.getCause() instanceof BreakAttr) {
348 return ((BreakAttr)(ae.getCause())).env;
349 } else {
350 throw ae;
351 }
352 } finally {
353 breakTree = null;
354 log.useSource(prev);
355 }
356 return env;
357 }
358
359 public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
360 breakTree = tree;
361 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
362 try {
363 attribStat(stmt, env);
364 } catch (BreakAttr b) {
365 return b.env;
366 } catch (AssertionError ae) {
367 if (ae.getCause() instanceof BreakAttr) {
368 return ((BreakAttr)(ae.getCause())).env;
369 } else {
370 throw ae;
371 }
372 } finally {
373 breakTree = null;
374 log.useSource(prev);
375 }
376 return env;
377 }
378
379 private JCTree breakTree = null;
380
381 private static class BreakAttr extends RuntimeException {
382 static final long serialVersionUID = -6924771130405446405L;
383 private Env<AttrContext> env;
384 private BreakAttr(Env<AttrContext> env) {
385 this.env = env;
386 }
387 }
388
389
390 /* ************************************************************************
391 * Visitor methods
392 *************************************************************************/
393
394 /** Visitor argument: the current environment.
395 */
396 Env<AttrContext> env;
397
398 /** Visitor argument: the currently expected proto-kind.
399 */
400 int pkind;
401
402 /** Visitor argument: the currently expected proto-type.
403 */
404 Type pt;
405
406 /** Visitor argument: the error key to be generated when a type error occurs
407 */
408 String errKey;
409
410 /** Visitor result: the computed type.
411 */
412 Type result;
413
414 /** Visitor method: attribute a tree, catching any completion failure
415 * exceptions. Return the tree's type.
416 *
417 * @param tree The tree to be visited.
418 * @param env The environment visitor argument.
419 * @param pkind The protokind visitor argument.
420 * @param pt The prototype visitor argument.
421 */
422 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) {
423 return attribTree(tree, env, pkind, pt, "incompatible.types");
424 }
425
426 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt, String errKey) {
427 Env<AttrContext> prevEnv = this.env;
428 int prevPkind = this.pkind;
429 Type prevPt = this.pt;
430 String prevErrKey = this.errKey;
431 try {
432 this.env = env;
433 this.pkind = pkind;
434 this.pt = pt;
435 this.errKey = errKey;
436 tree.accept(this);
437 if (tree == breakTree)
438 throw new BreakAttr(env);
439 return result;
440 } catch (CompletionFailure ex) {
441 tree.type = syms.errType;
442 return chk.completionError(tree.pos(), ex);
443 } finally {
444 this.env = prevEnv;
445 this.pkind = prevPkind;
446 this.pt = prevPt;
447 this.errKey = prevErrKey;
448 }
449 }
450
451 /** Derived visitor method: attribute an expression tree.
452 */
453 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
454 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
455 }
456
457 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt, String key) {
458 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType, key);
459 }
460
461 /** Derived visitor method: attribute an expression tree with
462 * no constraints on the computed type.
463 */
464 Type attribExpr(JCTree tree, Env<AttrContext> env) {
465 return attribTree(tree, env, VAL, Type.noType);
466 }
467
468 /** Derived visitor method: attribute a type tree.
469 */
470 Type attribType(JCTree tree, Env<AttrContext> env) {
471 Type result = attribType(tree, env, Type.noType);
472 return result;
473 }
474
475 /** Derived visitor method: attribute a type tree.
476 */
477 Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
478 Type result = attribTree(tree, env, TYP, pt);
479 return result;
480 }
481
482 /** Derived visitor method: attribute a statement or definition tree.
483 */
484 public Type attribStat(JCTree tree, Env<AttrContext> env) {
485 return attribTree(tree, env, NIL, Type.noType);
486 }
487
488 /** Attribute a list of expressions, returning a list of types.
489 */
490 List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
491 ListBuffer<Type> ts = new ListBuffer<Type>();
492 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
493 ts.append(attribExpr(l.head, env, pt));
494 return ts.toList();
495 }
496
497 /** Attribute a list of statements, returning nothing.
498 */
499 <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
500 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
501 attribStat(l.head, env);
502 }
503
504 /** Attribute the arguments in a method call, returning a list of types.
505 */
506 List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
507 ListBuffer<Type> argtypes = new ListBuffer<Type>();
508 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
509 argtypes.append(chk.checkNonVoid(
510 l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly))));
511 return argtypes.toList();
512 }
513
514 /** Attribute a type argument list, returning a list of types.
515 * Caller is responsible for calling checkRefTypes.
516 */
517 List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
518 ListBuffer<Type> argtypes = new ListBuffer<Type>();
519 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
520 argtypes.append(attribType(l.head, env));
521 return argtypes.toList();
522 }
523
524 /** Attribute a type argument list, returning a list of types.
525 * Check that all the types are references.
526 */
527 List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
528 List<Type> types = attribAnyTypes(trees, env);
529 return chk.checkRefTypes(trees, types);
530 }
531
532 /**
533 * Attribute type variables (of generic classes or methods).
534 * Compound types are attributed later in attribBounds.
535 * @param typarams the type variables to enter
536 * @param env the current environment
537 */
538 void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
539 for (JCTypeParameter tvar : typarams) {
540 TypeVar a = (TypeVar)tvar.type;
541 a.tsym.flags_field |= UNATTRIBUTED;
542 a.bound = Type.noType;
543 if (!tvar.bounds.isEmpty()) {
544 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
545 for (JCExpression bound : tvar.bounds.tail)
546 bounds = bounds.prepend(attribType(bound, env));
547 types.setBounds(a, bounds.reverse());
548 } else {
549 // if no bounds are given, assume a single bound of
550 // java.lang.Object.
551 types.setBounds(a, List.of(syms.objectType));
552 }
553 a.tsym.flags_field &= ~UNATTRIBUTED;
554 }
555 for (JCTypeParameter tvar : typarams)
556 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
557 attribStats(typarams, env);
558 }
559
560 void attribBounds(List<JCTypeParameter> typarams) {
561 for (JCTypeParameter typaram : typarams) {
562 Type bound = typaram.type.getUpperBound();
563 if (bound != null && bound.tsym instanceof ClassSymbol) {
564 ClassSymbol c = (ClassSymbol)bound.tsym;
565 if ((c.flags_field & COMPOUND) != 0) {
566 Assert.check((c.flags_field & UNATTRIBUTED) != 0, c);
567 attribClass(typaram.pos(), c);
568 }
569 }
570 }
571 }
572
573 /**
574 * Attribute the type references in a list of annotations.
575 */
576 void attribAnnotationTypes(List<JCAnnotation> annotations,
577 Env<AttrContext> env) {
578 for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
579 JCAnnotation a = al.head;
580 attribType(a.annotationType, env);
581 }
582 }
583
584 /**
585 * Attribute a "lazy constant value".
586 * @param env The env for the const value
587 * @param initializer The initializer for the const value
588 * @param type The expected type, or null
589 * @see VarSymbol#setlazyConstValue
590 */
591 public Object attribLazyConstantValue(Env<AttrContext> env,
592 JCTree.JCExpression initializer,
593 Type type) {
594
595 // in case no lint value has been set up for this env, scan up
596 // env stack looking for smallest enclosing env for which it is set.
597 Env<AttrContext> lintEnv = env;
598 while (lintEnv.info.lint == null)
599 lintEnv = lintEnv.next;
600
601 // Having found the enclosing lint value, we can initialize the lint value for this class
602 // ... but ...
603 // There's a problem with evaluating annotations in the right order, such that
604 // env.info.enclVar.attributes_field might not yet have been evaluated, and so might be
605 // null. In that case, calling augment will throw an NPE. To avoid this, for now we
606 // revert to the jdk 6 behavior and ignore the (unevaluated) attributes.
607 if (env.info.enclVar.attributes_field == null)
608 env.info.lint = lintEnv.info.lint;
609 else
610 env.info.lint = lintEnv.info.lint.augment(env.info.enclVar.attributes_field, env.info.enclVar.flags());
611
612 Lint prevLint = chk.setLint(env.info.lint);
613 JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
614
615 try {
616 Type itype = attribExpr(initializer, env, type);
617 if (itype.constValue() != null)
618 return coerce(itype, type).constValue();
619 else
620 return null;
621 } finally {
622 env.info.lint = prevLint;
623 log.useSource(prevSource);
624 }
625 }
626
627 /** Attribute type reference in an `extends' or `implements' clause.
628 * Supertypes of anonymous inner classes are usually already attributed.
629 *
630 * @param tree The tree making up the type reference.
631 * @param env The environment current at the reference.
632 * @param classExpected true if only a class is expected here.
633 * @param interfaceExpected true if only an interface is expected here.
634 */
635 Type attribBase(JCTree tree,
636 Env<AttrContext> env,
637 boolean classExpected,
638 boolean interfaceExpected,
639 boolean checkExtensible) {
640 Type t = tree.type != null ?
641 tree.type :
642 attribType(tree, env);
643 return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
644 }
645 Type checkBase(Type t,
646 JCTree tree,
647 Env<AttrContext> env,
648 boolean classExpected,
649 boolean interfaceExpected,
650 boolean checkExtensible) {
651 if (t.isErroneous())
652 return t;
653 if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
654 // check that type variable is already visible
655 if (t.getUpperBound() == null) {
656 log.error(tree.pos(), "illegal.forward.ref");
657 return types.createErrorType(t);
658 }
659 } else {
660 t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
661 }
662 if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
663 log.error(tree.pos(), "intf.expected.here");
664 // return errType is necessary since otherwise there might
665 // be undetected cycles which cause attribution to loop
666 return types.createErrorType(t);
667 } else if (checkExtensible &&
668 classExpected &&
669 (t.tsym.flags() & INTERFACE) != 0) {
670 log.error(tree.pos(), "no.intf.expected.here");
671 return types.createErrorType(t);
672 }
673 if (checkExtensible &&
674 ((t.tsym.flags() & FINAL) != 0)) {
675 log.error(tree.pos(),
676 "cant.inherit.from.final", t.tsym);
677 }
678 chk.checkNonCyclic(tree.pos(), t);
679 return t;
680 }
681
682 public void visitClassDef(JCClassDecl tree) {
683 // Local classes have not been entered yet, so we need to do it now:
684 if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
685 enter.classEnter(tree, env);
686
687 ClassSymbol c = tree.sym;
688 if (c == null) {
689 // exit in case something drastic went wrong during enter.
690 result = null;
691 } else {
692 // make sure class has been completed:
693 c.complete();
694
695 // If this class appears as an anonymous class
696 // in a superclass constructor call where
697 // no explicit outer instance is given,
698 // disable implicit outer instance from being passed.
699 // (This would be an illegal access to "this before super").
700 if (env.info.isSelfCall &&
701 env.tree.hasTag(NEWCLASS) &&
702 ((JCNewClass) env.tree).encl == null)
703 {
704 c.flags_field |= NOOUTERTHIS;
705 }
706 attribClass(tree.pos(), c);
707 result = tree.type = c.type;
708 }
709 }
710
711 public void visitMethodDef(JCMethodDecl tree) {
712 MethodSymbol m = tree.sym;
713
714 Lint lint = env.info.lint.augment(m.attributes_field, m.flags());
715 Lint prevLint = chk.setLint(lint);
716 MethodSymbol prevMethod = chk.setMethod(m);
717 try {
718 deferredLintHandler.flush(tree.pos());
719 chk.checkDeprecatedAnnotation(tree.pos(), m);
720
721 attribBounds(tree.typarams);
722
723 // If we override any other methods, check that we do so properly.
724 // JLS ???
725 if (m.isStatic()) {
726 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
727 } else {
728 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
729 }
730 chk.checkOverride(tree, m);
731
732 // Create a new environment with local scope
733 // for attributing the method.
734 Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
735
736 localEnv.info.lint = lint;
737
738 // Enter all type parameters into the local method scope.
739 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
740 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
741
742 ClassSymbol owner = env.enclClass.sym;
743 if ((owner.flags() & ANNOTATION) != 0 &&
744 tree.params.nonEmpty())
745 log.error(tree.params.head.pos(),
746 "intf.annotation.members.cant.have.params");
747
748 // Attribute all value parameters.
749 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
750 attribStat(l.head, localEnv);
751 }
752
753 chk.checkVarargsMethodDecl(localEnv, tree);
754
755 // Check that type parameters are well-formed.
756 chk.validate(tree.typarams, localEnv);
757
758 // Check that result type is well-formed.
759 chk.validate(tree.restype, localEnv);
760
761 // annotation method checks
762 if ((owner.flags() & ANNOTATION) != 0) {
763 // annotation method cannot have throws clause
764 if (tree.thrown.nonEmpty()) {
765 log.error(tree.thrown.head.pos(),
766 "throws.not.allowed.in.intf.annotation");
767 }
768 // annotation method cannot declare type-parameters
769 if (tree.typarams.nonEmpty()) {
770 log.error(tree.typarams.head.pos(),
771 "intf.annotation.members.cant.have.type.params");
772 }
773 // validate annotation method's return type (could be an annotation type)
774 chk.validateAnnotationType(tree.restype);
775 // ensure that annotation method does not clash with members of Object/Annotation
776 chk.validateAnnotationMethod(tree.pos(), m);
777
778 if (tree.defaultValue != null) {
779 // if default value is an annotation, check it is a well-formed
780 // annotation value (e.g. no duplicate values, no missing values, etc.)
781 chk.validateAnnotationTree(tree.defaultValue);
782 }
783 }
784
785 for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
786 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
787
788 if (tree.body == null) {
789 // Empty bodies are only allowed for
790 // abstract, native, or interface methods, or for methods
791 // in a retrofit signature class.
792 if ((owner.flags() & INTERFACE) == 0 &&
793 (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 &&
794 !relax)
795 log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
796 if (tree.defaultValue != null) {
797 if ((owner.flags() & ANNOTATION) == 0)
798 log.error(tree.pos(),
799 "default.allowed.in.intf.annotation.member");
800 }
801 } else if ((owner.flags() & INTERFACE) != 0) {
802 log.error(tree.body.pos(), "intf.meth.cant.have.body");
803 } else if ((tree.mods.flags & ABSTRACT) != 0) {
804 log.error(tree.pos(), "abstract.meth.cant.have.body");
805 } else if ((tree.mods.flags & NATIVE) != 0) {
806 log.error(tree.pos(), "native.meth.cant.have.body");
807 } else {
808 // Add an implicit super() call unless an explicit call to
809 // super(...) or this(...) is given
810 // or we are compiling class java.lang.Object.
811 if (tree.name == names.init && owner.type != syms.objectType) {
812 JCBlock body = tree.body;
813 if (body.stats.isEmpty() ||
814 !TreeInfo.isSelfCall(body.stats.head)) {
815 body.stats = body.stats.
816 prepend(memberEnter.SuperCall(make.at(body.pos),
817 List.<Type>nil(),
818 List.<JCVariableDecl>nil(),
819 false));
820 } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
821 (tree.mods.flags & GENERATEDCONSTR) == 0 &&
822 TreeInfo.isSuperCall(body.stats.head)) {
823 // enum constructors are not allowed to call super
824 // directly, so make sure there aren't any super calls
825 // in enum constructors, except in the compiler
826 // generated one.
827 log.error(tree.body.stats.head.pos(),
828 "call.to.super.not.allowed.in.enum.ctor",
829 env.enclClass.sym);
830 }
831 }
832
833 // Attribute method body.
834 attribStat(tree.body, localEnv);
835 }
836 localEnv.info.scope.leave();
837 result = tree.type = m.type;
838 chk.validateAnnotations(tree.mods.annotations, m);
839 }
840 finally {
841 chk.setLint(prevLint);
842 chk.setMethod(prevMethod);
843 }
844 }
845
846 public void visitVarDef(JCVariableDecl tree) {
847 // Local variables have not been entered yet, so we need to do it now:
848 if (env.info.scope.owner.kind == MTH) {
849 if (tree.sym != null) {
850 // parameters have already been entered
851 env.info.scope.enter(tree.sym);
852 } else {
853 memberEnter.memberEnter(tree, env);
854 annotate.flush();
855 }
856 tree.sym.flags_field |= EFFECTIVELY_FINAL;
857 }
858
859 VarSymbol v = tree.sym;
860 Lint lint = env.info.lint.augment(v.attributes_field, v.flags());
861 Lint prevLint = chk.setLint(lint);
862
863 // Check that the variable's declared type is well-formed.
864 chk.validate(tree.vartype, env);
865 deferredLintHandler.flush(tree.pos());
866
867 try {
868 chk.checkDeprecatedAnnotation(tree.pos(), v);
869
870 if (tree.init != null) {
871 if ((v.flags_field & FINAL) != 0 && !tree.init.hasTag(NEWCLASS)) {
872 // In this case, `v' is final. Ensure that it's initializer is
873 // evaluated.
874 v.getConstValue(); // ensure initializer is evaluated
875 } else {
876 // Attribute initializer in a new environment
877 // with the declared variable as owner.
878 // Check that initializer conforms to variable's declared type.
879 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
880 initEnv.info.lint = lint;
881 // In order to catch self-references, we set the variable's
882 // declaration position to maximal possible value, effectively
883 // marking the variable as undefined.
884 initEnv.info.enclVar = v;
885 attribExpr(tree.init, initEnv, v.type);
886 }
887 }
888 result = tree.type = v.type;
889 chk.validateAnnotations(tree.mods.annotations, v);
890 }
891 finally {
892 chk.setLint(prevLint);
893 }
894 }
895
896 public void visitSkip(JCSkip tree) {
897 result = null;
898 }
899
900 public void visitBlock(JCBlock tree) {
901 if (env.info.scope.owner.kind == TYP) {
902 // Block is a static or instance initializer;
903 // let the owner of the environment be a freshly
904 // created BLOCK-method.
905 Env<AttrContext> localEnv =
906 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
907 localEnv.info.scope.owner =
908 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
909 env.info.scope.owner);
910 if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
911 attribStats(tree.stats, localEnv);
912 } else {
913 // Create a new local environment with a local scope.
914 Env<AttrContext> localEnv =
915 env.dup(tree, env.info.dup(env.info.scope.dup()));
916 attribStats(tree.stats, localEnv);
917 localEnv.info.scope.leave();
918 }
919 result = null;
920 }
921
922 public void visitDoLoop(JCDoWhileLoop tree) {
923 attribStat(tree.body, env.dup(tree));
924 attribExpr(tree.cond, env, syms.booleanType);
925 result = null;
926 }
927
928 public void visitWhileLoop(JCWhileLoop tree) {
929 attribExpr(tree.cond, env, syms.booleanType);
930 attribStat(tree.body, env.dup(tree));
931 result = null;
932 }
933
934 public void visitForLoop(JCForLoop tree) {
935 Env<AttrContext> loopEnv =
936 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
937 attribStats(tree.init, loopEnv);
938 if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
939 loopEnv.tree = tree; // before, we were not in loop!
940 attribStats(tree.step, loopEnv);
941 attribStat(tree.body, loopEnv);
942 loopEnv.info.scope.leave();
943 result = null;
944 }
945
946 public void visitForeachLoop(JCEnhancedForLoop tree) {
947 Env<AttrContext> loopEnv =
948 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
949 attribStat(tree.var, loopEnv);
950 Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
951 chk.checkNonVoid(tree.pos(), exprType);
952 Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
953 if (elemtype == null) {
954 // or perhaps expr implements Iterable<T>?
955 Type base = types.asSuper(exprType, syms.iterableType.tsym);
956 if (base == null) {
957 log.error(tree.expr.pos(),
958 "foreach.not.applicable.to.type",
959 exprType,
960 diags.fragment("type.req.array.or.iterable"));
961 elemtype = types.createErrorType(exprType);
962 } else {
963 List<Type> iterableParams = base.allparams();
964 elemtype = iterableParams.isEmpty()
965 ? syms.objectType
966 : types.upperBound(iterableParams.head);
967 }
968 }
969 chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
970 loopEnv.tree = tree; // before, we were not in loop!
971 attribStat(tree.body, loopEnv);
972 loopEnv.info.scope.leave();
973 result = null;
974 }
975
976 public void visitLabelled(JCLabeledStatement tree) {
977 // Check that label is not used in an enclosing statement
978 Env<AttrContext> env1 = env;
979 while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
980 if (env1.tree.hasTag(LABELLED) &&
981 ((JCLabeledStatement) env1.tree).label == tree.label) {
982 log.error(tree.pos(), "label.already.in.use",
983 tree.label);
984 break;
985 }
986 env1 = env1.next;
987 }
988
989 attribStat(tree.body, env.dup(tree));
990 result = null;
991 }
992
993 public void visitSwitch(JCSwitch tree) {
994 Type seltype = attribExpr(tree.selector, env);
995
996 Env<AttrContext> switchEnv =
997 env.dup(tree, env.info.dup(env.info.scope.dup()));
998
999 boolean enumSwitch =
1000 allowEnums &&
1001 (seltype.tsym.flags() & Flags.ENUM) != 0;
1002 boolean stringSwitch = false;
1003 if (types.isSameType(seltype, syms.stringType)) {
1004 if (allowStringsInSwitch) {
1005 stringSwitch = true;
1006 } else {
1007 log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName);
1008 }
1009 }
1010 if (!enumSwitch && !stringSwitch)
1011 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
1012
1013 // Attribute all cases and
1014 // check that there are no duplicate case labels or default clauses.
1015 Set<Object> labels = new HashSet<Object>(); // The set of case labels.
1016 boolean hasDefault = false; // Is there a default label?
1017 for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
1018 JCCase c = l.head;
1019 Env<AttrContext> caseEnv =
1020 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
1021 if (c.pat != null) {
1022 if (enumSwitch) {
1023 Symbol sym = enumConstant(c.pat, seltype);
1024 if (sym == null) {
1025 log.error(c.pat.pos(), "enum.label.must.be.unqualified.enum");
1026 } else if (!labels.add(sym)) {
1027 log.error(c.pos(), "duplicate.case.label");
1028 }
1029 } else {
1030 Type pattype = attribExpr(c.pat, switchEnv, seltype);
1031 if (pattype.tag != ERROR) {
1032 if (pattype.constValue() == null) {
1033 log.error(c.pat.pos(),
1034 (stringSwitch ? "string.const.req" : "const.expr.req"));
1035 } else if (labels.contains(pattype.constValue())) {
1036 log.error(c.pos(), "duplicate.case.label");
1037 } else {
1038 labels.add(pattype.constValue());
1039 }
1040 }
1041 }
1042 } else if (hasDefault) {
1043 log.error(c.pos(), "duplicate.default.label");
1044 } else {
1045 hasDefault = true;
1046 }
1047 attribStats(c.stats, caseEnv);
1048 caseEnv.info.scope.leave();
1049 addVars(c.stats, switchEnv.info.scope);
1050 }
1051
1052 switchEnv.info.scope.leave();
1053 result = null;
1054 }
1055 // where
1056 /** Add any variables defined in stats to the switch scope. */
1057 private static void addVars(List<JCStatement> stats, Scope switchScope) {
1058 for (;stats.nonEmpty(); stats = stats.tail) {
1059 JCTree stat = stats.head;
1060 if (stat.hasTag(VARDEF))
1061 switchScope.enter(((JCVariableDecl) stat).sym);
1062 }
1063 }
1064 // where
1065 /** Return the selected enumeration constant symbol, or null. */
1066 private Symbol enumConstant(JCTree tree, Type enumType) {
1067 if (!tree.hasTag(IDENT)) {
1068 log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
1069 return syms.errSymbol;
1070 }
1071 JCIdent ident = (JCIdent)tree;
1072 Name name = ident.name;
1073 for (Scope.Entry e = enumType.tsym.members().lookup(name);
1074 e.scope != null; e = e.next()) {
1075 if (e.sym.kind == VAR) {
1076 Symbol s = ident.sym = e.sym;
1077 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1078 ident.type = s.type;
1079 return ((s.flags_field & Flags.ENUM) == 0)
1080 ? null : s;
1081 }
1082 }
1083 return null;
1084 }
1085
1086 public void visitSynchronized(JCSynchronized tree) {
1087 chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
1088 attribStat(tree.body, env);
1089 result = null;
1090 }
1091
1092 public void visitTry(JCTry tree) {
1093 // Create a new local environment with a local
1094 Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1095 boolean isTryWithResource = tree.resources.nonEmpty();
1096 // Create a nested environment for attributing the try block if needed
1097 Env<AttrContext> tryEnv = isTryWithResource ?
1098 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1099 localEnv;
1100 // Attribute resource declarations
1101 for (JCTree resource : tree.resources) {
1102 if (resource.hasTag(VARDEF)) {
1103 attribStat(resource, tryEnv);
1104 chk.checkType(resource, resource.type, syms.autoCloseableType, "try.not.applicable.to.type");
1105
1106 //check that resource type cannot throw InterruptedException
1107 checkAutoCloseable(resource.pos(), localEnv, resource.type);
1108
1109 VarSymbol var = (VarSymbol)TreeInfo.symbolFor(resource);
1110 var.setData(ElementKind.RESOURCE_VARIABLE);
1111 } else {
1112 attribExpr(resource, tryEnv, syms.autoCloseableType, "try.not.applicable.to.type");
1113 }
1114 }
1115 // Attribute body
1116 attribStat(tree.body, tryEnv);
1117 if (isTryWithResource)
1118 tryEnv.info.scope.leave();
1119
1120 // Attribute catch clauses
1121 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
1122 JCCatch c = l.head;
1123 Env<AttrContext> catchEnv =
1124 localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
1125 Type ctype = attribStat(c.param, catchEnv);
1126 if (TreeInfo.isMultiCatch(c)) {
1127 //multi-catch parameter is implicitly marked as final
1128 c.param.sym.flags_field |= FINAL | UNION;
1129 }
1130 if (c.param.sym.kind == Kinds.VAR) {
1131 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
1132 }
1133 chk.checkType(c.param.vartype.pos(),
1134 chk.checkClassType(c.param.vartype.pos(), ctype),
1135 syms.throwableType);
1136 attribStat(c.body, catchEnv);
1137 catchEnv.info.scope.leave();
1138 }
1139
1140 // Attribute finalizer
1141 if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
1142
1143 localEnv.info.scope.leave();
1144 result = null;
1145 }
1146
1147 void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
1148 if (!resource.isErroneous() &&
1149 types.asSuper(resource, syms.autoCloseableType.tsym) != null) {
1150 Symbol close = syms.noSymbol;
1151 boolean prevDeferDiags = log.deferDiagnostics;
1152 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
1153 try {
1154 log.deferDiagnostics = true;
1155 log.deferredDiagnostics = ListBuffer.lb();
1156 close = rs.resolveQualifiedMethod(pos,
1157 env,
1158 resource,
1159 names.close,
1160 List.<Type>nil(),
1161 List.<Type>nil());
1162 }
1163 finally {
1164 log.deferDiagnostics = prevDeferDiags;
1165 log.deferredDiagnostics = prevDeferredDiags;
1166 }
1167 if (close.kind == MTH &&
1168 close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
1169 chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
1170 env.info.lint.isEnabled(LintCategory.TRY)) {
1171 log.warning(LintCategory.TRY, pos, "try.resource.throws.interrupted.exc", resource);
1172 }
1173 }
1174 }
1175
1176 public void visitConditional(JCConditional tree) {
1177 attribExpr(tree.cond, env, syms.booleanType);
1178 attribExpr(tree.truepart, env);
1179 attribExpr(tree.falsepart, env);
1180 result = check(tree,
1181 capture(condType(tree.pos(), tree.cond.type,
1182 tree.truepart.type, tree.falsepart.type)),
1183 VAL, pkind, pt);
1184 }
1185 //where
1186 /** Compute the type of a conditional expression, after
1187 * checking that it exists. See Spec 15.25.
1188 *
1189 * @param pos The source position to be used for
1190 * error diagnostics.
1191 * @param condtype The type of the expression's condition.
1192 * @param thentype The type of the expression's then-part.
1193 * @param elsetype The type of the expression's else-part.
1194 */
1195 private Type condType(DiagnosticPosition pos,
1196 Type condtype,
1197 Type thentype,
1198 Type elsetype) {
1199 Type ctype = condType1(pos, condtype, thentype, elsetype);
1200
1201 // If condition and both arms are numeric constants,
1202 // evaluate at compile-time.
1203 return ((condtype.constValue() != null) &&
1204 (thentype.constValue() != null) &&
1205 (elsetype.constValue() != null))
1206 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
1207 : ctype;
1208 }
1209 /** Compute the type of a conditional expression, after
1210 * checking that it exists. Does not take into
1211 * account the special case where condition and both arms
1212 * are constants.
1213 *
1214 * @param pos The source position to be used for error
1215 * diagnostics.
1216 * @param condtype The type of the expression's condition.
1217 * @param thentype The type of the expression's then-part.
1218 * @param elsetype The type of the expression's else-part.
1219 */
1220 private Type condType1(DiagnosticPosition pos, Type condtype,
1221 Type thentype, Type elsetype) {
1222 // If same type, that is the result
1223 if (types.isSameType(thentype, elsetype))
1224 return thentype.baseType();
1225
1226 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1227 ? thentype : types.unboxedType(thentype);
1228 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1229 ? elsetype : types.unboxedType(elsetype);
1230
1231 // Otherwise, if both arms can be converted to a numeric
1232 // type, return the least numeric type that fits both arms
1233 // (i.e. return larger of the two, or return int if one
1234 // arm is short, the other is char).
1235 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1236 // If one arm has an integer subrange type (i.e., byte,
1237 // short, or char), and the other is an integer constant
1238 // that fits into the subrange, return the subrange type.
1239 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1240 types.isAssignable(elseUnboxed, thenUnboxed))
1241 return thenUnboxed.baseType();
1242 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1243 types.isAssignable(thenUnboxed, elseUnboxed))
1244 return elseUnboxed.baseType();
1245
1246 for (int i = BYTE; i < VOID; i++) {
1247 Type candidate = syms.typeOfTag[i];
1248 if (types.isSubtype(thenUnboxed, candidate) &&
1249 types.isSubtype(elseUnboxed, candidate))
1250 return candidate;
1251 }
1252 }
1253
1254 // Those were all the cases that could result in a primitive
1255 if (allowBoxing) {
1256 if (thentype.isPrimitive())
1257 thentype = types.boxedClass(thentype).type;
1258 if (elsetype.isPrimitive())
1259 elsetype = types.boxedClass(elsetype).type;
1260 }
1261
1262 if (types.isSubtype(thentype, elsetype))
1263 return elsetype.baseType();
1264 if (types.isSubtype(elsetype, thentype))
1265 return thentype.baseType();
1266
1267 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1268 log.error(pos, "neither.conditional.subtype",
1269 thentype, elsetype);
1270 return thentype.baseType();
1271 }
1272
1273 // both are known to be reference types. The result is
1274 // lub(thentype,elsetype). This cannot fail, as it will
1275 // always be possible to infer "Object" if nothing better.
1276 return types.lub(thentype.baseType(), elsetype.baseType());
1277 }
1278
1279 public void visitIf(JCIf tree) {
1280 attribExpr(tree.cond, env, syms.booleanType);
1281 attribStat(tree.thenpart, env);
1282 if (tree.elsepart != null)
1283 attribStat(tree.elsepart, env);
1284 chk.checkEmptyIf(tree);
1285 result = null;
1286 }
1287
1288 public void visitExec(JCExpressionStatement tree) {
1289 //a fresh environment is required for 292 inference to work properly ---
1290 //see Infer.instantiatePolymorphicSignatureInstance()
1291 Env<AttrContext> localEnv = env.dup(tree);
1292 attribExpr(tree.expr, localEnv);
1293 result = null;
1294 }
1295
1296 public void visitBreak(JCBreak tree) {
1297 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1298 result = null;
1299 }
1300
1301 public void visitContinue(JCContinue tree) {
1302 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1303 result = null;
1304 }
1305 //where
1306 /** Return the target of a break or continue statement, if it exists,
1307 * report an error if not.
1308 * Note: The target of a labelled break or continue is the
1309 * (non-labelled) statement tree referred to by the label,
1310 * not the tree representing the labelled statement itself.
1311 *
1312 * @param pos The position to be used for error diagnostics
1313 * @param tag The tag of the jump statement. This is either
1314 * Tree.BREAK or Tree.CONTINUE.
1315 * @param label The label of the jump statement, or null if no
1316 * label is given.
1317 * @param env The environment current at the jump statement.
1318 */
1319 private JCTree findJumpTarget(DiagnosticPosition pos,
1320 JCTree.Tag tag,
1321 Name label,
1322 Env<AttrContext> env) {
1323 // Search environments outwards from the point of jump.
1324 Env<AttrContext> env1 = env;
1325 LOOP:
1326 while (env1 != null) {
1327 switch (env1.tree.getTag()) {
1328 case LABELLED:
1329 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1330 if (label == labelled.label) {
1331 // If jump is a continue, check that target is a loop.
1332 if (tag == CONTINUE) {
1333 if (!labelled.body.hasTag(DOLOOP) &&
1334 !labelled.body.hasTag(WHILELOOP) &&
1335 !labelled.body.hasTag(FORLOOP) &&
1336 !labelled.body.hasTag(FOREACHLOOP))
1337 log.error(pos, "not.loop.label", label);
1338 // Found labelled statement target, now go inwards
1339 // to next non-labelled tree.
1340 return TreeInfo.referencedStatement(labelled);
1341 } else {
1342 return labelled;
1343 }
1344 }
1345 break;
1346 case DOLOOP:
1347 case WHILELOOP:
1348 case FORLOOP:
1349 case FOREACHLOOP:
1350 if (label == null) return env1.tree;
1351 break;
1352 case SWITCH:
1353 if (label == null && tag == BREAK) return env1.tree;
1354 break;
1355 case METHODDEF:
1356 case CLASSDEF:
1357 break LOOP;
1358 default:
1359 }
1360 env1 = env1.next;
1361 }
1362 if (label != null)
1363 log.error(pos, "undef.label", label);
1364 else if (tag == CONTINUE)
1365 log.error(pos, "cont.outside.loop");
1366 else
1367 log.error(pos, "break.outside.switch.loop");
1368 return null;
1369 }
1370
1371 public void visitReturn(JCReturn tree) {
1372 // Check that there is an enclosing method which is
1373 // nested within than the enclosing class.
1374 if (env.enclMethod == null ||
1375 env.enclMethod.sym.owner != env.enclClass.sym) {
1376 log.error(tree.pos(), "ret.outside.meth");
1377
1378 } else {
1379 // Attribute return expression, if it exists, and check that
1380 // it conforms to result type of enclosing method.
1381 Symbol m = env.enclMethod.sym;
1382 if (m.type.getReturnType().tag == VOID) {
1383 if (tree.expr != null)
1384 log.error(tree.expr.pos(),
1385 "cant.ret.val.from.meth.decl.void");
1386 } else if (tree.expr == null) {
1387 log.error(tree.pos(), "missing.ret.val");
1388 } else {
1389 attribExpr(tree.expr, env, m.type.getReturnType());
1390 }
1391 }
1392 result = null;
1393 }
1394
1395 public void visitThrow(JCThrow tree) {
1396 attribExpr(tree.expr, env, syms.throwableType);
1397 result = null;
1398 }
1399
1400 public void visitAssert(JCAssert tree) {
1401 attribExpr(tree.cond, env, syms.booleanType);
1402 if (tree.detail != null) {
1403 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1404 }
1405 result = null;
1406 }
1407
1408 /** Visitor method for method invocations.
1409 * NOTE: The method part of an application will have in its type field
1410 * the return type of the method, not the method's type itself!
1411 */
1412 public void visitApply(JCMethodInvocation tree) {
1413 // The local environment of a method application is
1414 // a new environment nested in the current one.
1415 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1416
1417 // The types of the actual method arguments.
1418 List<Type> argtypes;
1419
1420 // The types of the actual method type arguments.
1421 List<Type> typeargtypes = null;
1422
1423 Name methName = TreeInfo.name(tree.meth);
1424
1425 boolean isConstructorCall =
1426 methName == names._this || methName == names._super;
1427
1428 if (isConstructorCall) {
1429 // We are seeing a ...this(...) or ...super(...) call.
1430 // Check that this is the first statement in a constructor.
1431 if (checkFirstConstructorStat(tree, env)) {
1432
1433 // Record the fact
1434 // that this is a constructor call (using isSelfCall).
1435 localEnv.info.isSelfCall = true;
1436
1437 // Attribute arguments, yielding list of argument types.
1438 argtypes = attribArgs(tree.args, localEnv);
1439 typeargtypes = attribTypes(tree.typeargs, localEnv);
1440
1441 // Variable `site' points to the class in which the called
1442 // constructor is defined.
1443 Type site = env.enclClass.sym.type;
1444 if (methName == names._super) {
1445 if (site == syms.objectType) {
1446 log.error(tree.meth.pos(), "no.superclass", site);
1447 site = types.createErrorType(syms.objectType);
1448 } else {
1449 site = types.supertype(site);
1450 }
1451 }
1452
1453 if (site.tag == CLASS) {
1454 Type encl = site.getEnclosingType();
1455 while (encl != null && encl.tag == TYPEVAR)
1456 encl = encl.getUpperBound();
1457 if (encl.tag == CLASS) {
1458 // we are calling a nested class
1459
1460 if (tree.meth.hasTag(SELECT)) {
1461 JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1462
1463 // We are seeing a prefixed call, of the form
1464 // <expr>.super(...).
1465 // Check that the prefix expression conforms
1466 // to the outer instance type of the class.
1467 chk.checkRefType(qualifier.pos(),
1468 attribExpr(qualifier, localEnv,
1469 encl));
1470 } else if (methName == names._super) {
1471 // qualifier omitted; check for existence
1472 // of an appropriate implicit qualifier.
1473 rs.resolveImplicitThis(tree.meth.pos(),
1474 localEnv, site, true);
1475 }
1476 } else if (tree.meth.hasTag(SELECT)) {
1477 log.error(tree.meth.pos(), "illegal.qual.not.icls",
1478 site.tsym);
1479 }
1480
1481 // if we're calling a java.lang.Enum constructor,
1482 // prefix the implicit String and int parameters
1483 if (site.tsym == syms.enumSym && allowEnums)
1484 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1485
1486 // Resolve the called constructor under the assumption
1487 // that we are referring to a superclass instance of the
1488 // current instance (JLS ???).
1489 boolean selectSuperPrev = localEnv.info.selectSuper;
1490 localEnv.info.selectSuper = true;
1491 localEnv.info.varArgs = false;
1492 Symbol sym = rs.resolveConstructor(
1493 tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1494 localEnv.info.selectSuper = selectSuperPrev;
1495
1496 // Set method symbol to resolved constructor...
1497 TreeInfo.setSymbol(tree.meth, sym);
1498
1499 // ...and check that it is legal in the current context.
1500 // (this will also set the tree's type)
1501 Type mpt = newMethTemplate(argtypes, typeargtypes);
1502 checkId(tree.meth, site, sym, localEnv, MTH,
1503 mpt, tree.varargsElement != null);
1504 }
1505 // Otherwise, `site' is an error type and we do nothing
1506 }
1507 result = tree.type = syms.voidType;
1508 } else {
1509 // Otherwise, we are seeing a regular method call.
1510 // Attribute the arguments, yielding list of argument types, ...
1511 argtypes = attribArgs(tree.args, localEnv);
1512 typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
1513
1514 // ... and attribute the method using as a prototype a methodtype
1515 // whose formal argument types is exactly the list of actual
1516 // arguments (this will also set the method symbol).
1517 Type mpt = newMethTemplate(argtypes, typeargtypes);
1518 localEnv.info.varArgs = false;
1519 Type mtype = attribExpr(tree.meth, localEnv, mpt);
1520 if (localEnv.info.varArgs)
1521 Assert.check(mtype.isErroneous() || tree.varargsElement != null);
1522
1523 // Compute the result type.
1524 Type restype = mtype.getReturnType();
1525 if (restype.tag == WILDCARD)
1526 throw new AssertionError(mtype);
1527
1528 // as a special case, array.clone() has a result that is
1529 // the same as static type of the array being cloned
1530 if (tree.meth.hasTag(SELECT) &&
1531 allowCovariantReturns &&
1532 methName == names.clone &&
1533 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1534 restype = ((JCFieldAccess) tree.meth).selected.type;
1535
1536 // as a special case, x.getClass() has type Class<? extends |X|>
1537 if (allowGenerics &&
1538 methName == names.getClass && tree.args.isEmpty()) {
1539 Type qualifier = (tree.meth.hasTag(SELECT))
1540 ? ((JCFieldAccess) tree.meth).selected.type
1541 : env.enclClass.sym.type;
1542 restype = new
1543 ClassType(restype.getEnclosingType(),
1544 List.<Type>of(new WildcardType(types.erasure(qualifier),
1545 BoundKind.EXTENDS,
1546 syms.boundClass)),
1547 restype.tsym);
1548 }
1549
1550 chk.checkRefTypes(tree.typeargs, typeargtypes);
1551
1552 // Check that value of resulting type is admissible in the
1553 // current context. Also, capture the return type
1554 result = check(tree, capture(restype), VAL, pkind, pt);
1555 }
1556 chk.validate(tree.typeargs, localEnv);
1557 }
1558 //where
1559 /** Check that given application node appears as first statement
1560 * in a constructor call.
1561 * @param tree The application node
1562 * @param env The environment current at the application.
1563 */
1564 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1565 JCMethodDecl enclMethod = env.enclMethod;
1566 if (enclMethod != null && enclMethod.name == names.init) {
1567 JCBlock body = enclMethod.body;
1568 if (body.stats.head.hasTag(EXEC) &&
1569 ((JCExpressionStatement) body.stats.head).expr == tree)
1570 return true;
1571 }
1572 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1573 TreeInfo.name(tree.meth));
1574 return false;
1575 }
1576
1577 /** Obtain a method type with given argument types.
1578 */
1579 Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
1580 MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
1581 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1582 }
1583
1584 public void visitNewClass(JCNewClass tree) {
1585 Type owntype = types.createErrorType(tree.type);
1586
1587 // The local environment of a class creation is
1588 // a new environment nested in the current one.
1589 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1590
1591 // The anonymous inner class definition of the new expression,
1592 // if one is defined by it.
1593 JCClassDecl cdef = tree.def;
1594
1595 // If enclosing class is given, attribute it, and
1596 // complete class name to be fully qualified
1597 JCExpression clazz = tree.clazz; // Class field following new
1598 JCExpression clazzid = // Identifier in class field
1599 (clazz.hasTag(TYPEAPPLY))
1600 ? ((JCTypeApply) clazz).clazz
1601 : clazz;
1602
1603 JCExpression clazzid1 = clazzid; // The same in fully qualified form
1604
1605 if (tree.encl != null) {
1606 // We are seeing a qualified new, of the form
1607 // <expr>.new C <...> (...) ...
1608 // In this case, we let clazz stand for the name of the
1609 // allocated class C prefixed with the type of the qualifier
1610 // expression, so that we can
1611 // resolve it with standard techniques later. I.e., if
1612 // <expr> has type T, then <expr>.new C <...> (...)
1613 // yields a clazz T.C.
1614 Type encltype = chk.checkRefType(tree.encl.pos(),
1615 attribExpr(tree.encl, env));
1616 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1617 ((JCIdent) clazzid).name);
1618 if (clazz.hasTag(TYPEAPPLY))
1619 clazz = make.at(tree.pos).
1620 TypeApply(clazzid1,
1621 ((JCTypeApply) clazz).arguments);
1622 else
1623 clazz = clazzid1;
1624 }
1625
1626 // Attribute clazz expression and store
1627 // symbol + type back into the attributed tree.
1628 Type clazztype = attribType(clazz, env);
1629 Pair<Scope,Scope> mapping = getSyntheticScopeMapping(clazztype);
1630 clazztype = chk.checkDiamond(tree, clazztype);
1631 chk.validate(clazz, localEnv);
1632 if (tree.encl != null) {
1633 // We have to work in this case to store
1634 // symbol + type back into the attributed tree.
1635 tree.clazz.type = clazztype;
1636 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1637 clazzid.type = ((JCIdent) clazzid).sym.type;
1638 if (!clazztype.isErroneous()) {
1639 if (cdef != null && clazztype.tsym.isInterface()) {
1640 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1641 } else if (clazztype.tsym.isStatic()) {
1642 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1643 }
1644 }
1645 } else if (!clazztype.tsym.isInterface() &&
1646 clazztype.getEnclosingType().tag == CLASS) {
1647 // Check for the existence of an apropos outer instance
1648 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1649 }
1650
1651 // Attribute constructor arguments.
1652 List<Type> argtypes = attribArgs(tree.args, localEnv);
1653 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1654
1655 if (TreeInfo.isDiamond(tree) && !clazztype.isErroneous()) {
1656 clazztype = attribDiamond(localEnv, tree, clazztype, mapping, argtypes, typeargtypes);
1657 clazz.type = clazztype;
1658 } else if (allowDiamondFinder &&
1659 tree.def == null &&
1660 !clazztype.isErroneous() &&
1661 clazztype.getTypeArguments().nonEmpty() &&
1662 findDiamonds) {
1663 boolean prevDeferDiags = log.deferDiagnostics;
1664 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
1665 Type inferred = null;
1666 try {
1667 //disable diamond-related diagnostics
1668 log.deferDiagnostics = true;
1669 log.deferredDiagnostics = ListBuffer.lb();
1670 inferred = attribDiamond(localEnv,
1671 tree,
1672 clazztype,
1673 mapping,
1674 argtypes,
1675 typeargtypes);
1676 }
1677 finally {
1678 log.deferDiagnostics = prevDeferDiags;
1679 log.deferredDiagnostics = prevDeferredDiags;
1680 }
1681 if (inferred != null &&
1682 !inferred.isErroneous() &&
1683 inferred.tag == CLASS &&
1684 types.isAssignable(inferred, pt.tag == NONE ? clazztype : pt, Warner.noWarnings)) {
1685 String key = types.isSameType(clazztype, inferred) ?
1686 "diamond.redundant.args" :
1687 "diamond.redundant.args.1";
1688 log.warning(tree.clazz.pos(), key, clazztype, inferred);
1689 }
1690 }
1691
1692 // If we have made no mistakes in the class type...
1693 if (clazztype.tag == CLASS) {
1694 // Enums may not be instantiated except implicitly
1695 if (allowEnums &&
1696 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1697 (!env.tree.hasTag(VARDEF) ||
1698 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1699 ((JCVariableDecl) env.tree).init != tree))
1700 log.error(tree.pos(), "enum.cant.be.instantiated");
1701 // Check that class is not abstract
1702 if (cdef == null &&
1703 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1704 log.error(tree.pos(), "abstract.cant.be.instantiated",
1705 clazztype.tsym);
1706 } else if (cdef != null && clazztype.tsym.isInterface()) {
1707 // Check that no constructor arguments are given to
1708 // anonymous classes implementing an interface
1709 if (!argtypes.isEmpty())
1710 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1711
1712 if (!typeargtypes.isEmpty())
1713 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1714
1715 // Error recovery: pretend no arguments were supplied.
1716 argtypes = List.nil();
1717 typeargtypes = List.nil();
1718 }
1719
1720 // Resolve the called constructor under the assumption
1721 // that we are referring to a superclass instance of the
1722 // current instance (JLS ???).
1723 else {
1724 //the following code alters some of the fields in the current
1725 //AttrContext - hence, the current context must be dup'ed in
1726 //order to avoid downstream failures
1727 Env<AttrContext> rsEnv = localEnv.dup(tree);
1728 rsEnv.info.selectSuper = cdef != null;
1729 rsEnv.info.varArgs = false;
1730 tree.constructor = rs.resolveConstructor(
1731 tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
1732 tree.constructorType = tree.constructor.type.isErroneous() ?
1733 syms.errType :
1734 checkMethod(clazztype,
1735 tree.constructor,
1736 rsEnv,
1737 tree.args,
1738 argtypes,
1739 typeargtypes,
1740 rsEnv.info.varArgs);
1741 if (rsEnv.info.varArgs)
1742 Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
1743 }
1744
1745 if (cdef != null) {
1746 // We are seeing an anonymous class instance creation.
1747 // In this case, the class instance creation
1748 // expression
1749 //
1750 // E.new <typeargs1>C<typargs2>(args) { ... }
1751 //
1752 // is represented internally as
1753 //
1754 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1755 //
1756 // This expression is then *transformed* as follows:
1757 //
1758 // (1) add a STATIC flag to the class definition
1759 // if the current environment is static
1760 // (2) add an extends or implements clause
1761 // (3) add a constructor.
1762 //
1763 // For instance, if C is a class, and ET is the type of E,
1764 // the expression
1765 //
1766 // E.new <typeargs1>C<typargs2>(args) { ... }
1767 //
1768 // is translated to (where X is a fresh name and typarams is the
1769 // parameter list of the super constructor):
1770 //
1771 // new <typeargs1>X(<*nullchk*>E, args) where
1772 // X extends C<typargs2> {
1773 // <typarams> X(ET e, args) {
1774 // e.<typeargs1>super(args)
1775 // }
1776 // ...
1777 // }
1778 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1779
1780 if (clazztype.tsym.isInterface()) {
1781 cdef.implementing = List.of(clazz);
1782 } else {
1783 cdef.extending = clazz;
1784 }
1785
1786 attribStat(cdef, localEnv);
1787
1788 // If an outer instance is given,
1789 // prefix it to the constructor arguments
1790 // and delete it from the new expression
1791 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1792 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1793 argtypes = argtypes.prepend(tree.encl.type);
1794 tree.encl = null;
1795 }
1796
1797 // Reassign clazztype and recompute constructor.
1798 clazztype = cdef.sym.type;
1799 boolean useVarargs = tree.varargsElement != null;
1800 Symbol sym = rs.resolveConstructor(
1801 tree.pos(), localEnv, clazztype, argtypes,
1802 typeargtypes, true, useVarargs);
1803 Assert.check(sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous());
1804 tree.constructor = sym;
1805 if (tree.constructor.kind > ERRONEOUS) {
1806 tree.constructorType = syms.errType;
1807 }
1808 else {
1809 tree.constructorType = checkMethod(clazztype,
1810 tree.constructor,
1811 localEnv,
1812 tree.args,
1813 argtypes,
1814 typeargtypes,
1815 useVarargs);
1816 }
1817 }
1818
1819 if (tree.constructor != null && tree.constructor.kind == MTH)
1820 owntype = clazztype;
1821 }
1822 result = check(tree, owntype, VAL, pkind, pt);
1823 chk.validate(tree.typeargs, localEnv);
1824 }
1825
1826 Type attribDiamond(Env<AttrContext> env,
1827 JCNewClass tree,
1828 Type clazztype,
1829 Pair<Scope, Scope> mapping,
1830 List<Type> argtypes,
1831 List<Type> typeargtypes) {
1832 if (clazztype.isErroneous() ||
1833 clazztype.isInterface() ||
1834 mapping == erroneousMapping) {
1835 //if the type of the instance creation expression is erroneous,
1836 //or if it's an interface, or if something prevented us to form a valid
1837 //mapping, return the (possibly erroneous) type unchanged
1838 return clazztype;
1839 }
1840
1841 //dup attribution environment and augment the set of inference variables
1842 Env<AttrContext> localEnv = env.dup(tree);
1843 localEnv.info.tvars = clazztype.tsym.type.getTypeArguments();
1844
1845 //if the type of the instance creation expression is a class type
1846 //apply method resolution inference (JLS 15.12.2.7). The return type
1847 //of the resolved constructor will be a partially instantiated type
1848 ((ClassSymbol) clazztype.tsym).members_field = mapping.snd;
1849 Symbol constructor;
1850 try {
1851 constructor = rs.resolveDiamond(tree.pos(),
1852 localEnv,
1853 clazztype,
1854 argtypes,
1855 typeargtypes);
1856 } finally {
1857 ((ClassSymbol) clazztype.tsym).members_field = mapping.fst;
1858 }
1859 if (constructor.kind == MTH) {
1860 ClassType ct = new ClassType(clazztype.getEnclosingType(),
1861 clazztype.tsym.type.getTypeArguments(),
1862 clazztype.tsym);
1863 clazztype = checkMethod(ct,
1864 constructor,
1865 localEnv,
1866 tree.args,
1867 argtypes,
1868 typeargtypes,
1869 localEnv.info.varArgs).getReturnType();
1870 } else {
1871 clazztype = syms.errType;
1872 }
1873
1874 if (clazztype.tag == FORALL && !pt.isErroneous()) {
1875 //if the resolved constructor's return type has some uninferred
1876 //type-variables, infer them using the expected type and declared
1877 //bounds (JLS 15.12.2.8).
1878 try {
1879 clazztype = infer.instantiateExpr((ForAll) clazztype,
1880 pt.tag == NONE ? syms.objectType : pt,
1881 Warner.noWarnings);
1882 } catch (Infer.InferenceException ex) {
1883 //an error occurred while inferring uninstantiated type-variables
1884 log.error(tree.clazz.pos(),
1885 "cant.apply.diamond.1",
1886 diags.fragment("diamond", clazztype.tsym),
1887 ex.diagnostic);
1888 }
1889 }
1890 return chk.checkClassType(tree.clazz.pos(),
1891 clazztype,
1892 true);
1893 }
1894
1895 /** Creates a synthetic scope containing fake generic constructors.
1896 * Assuming that the original scope contains a constructor of the kind:
1897 * Foo(X x, Y y), where X,Y are class type-variables declared in Foo,
1898 * the synthetic scope is added a generic constructor of the kind:
1899 * <X,Y>Foo<X,Y>(X x, Y y). This is crucial in order to enable diamond
1900 * inference. The inferred return type of the synthetic constructor IS
1901 * the inferred type for the diamond operator.
1902 */
1903 private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype) {
1904 if (ctype.tag != CLASS) {
1905 return erroneousMapping;
1906 }
1907
1908 Pair<Scope, Scope> mapping =
1909 new Pair<Scope, Scope>(ctype.tsym.members(), new Scope(ctype.tsym));
1910
1911 //for each constructor in the original scope, create a synthetic constructor
1912 //whose return type is the type of the class in which the constructor is
1913 //declared, and insert it into the new scope.
1914 for (Scope.Entry e = mapping.fst.lookup(names.init);
1915 e.scope != null;
1916 e = e.next()) {
1917 Type synthRestype = new ClassType(ctype.getEnclosingType(),
1918 ctype.tsym.type.getTypeArguments(),
1919 ctype.tsym);
1920 MethodSymbol synhConstr = new MethodSymbol(e.sym.flags(),
1921 names.init,
1922 types.createMethodTypeWithReturn(e.sym.type, synthRestype),
1923 e.sym.owner);
1924 mapping.snd.enter(synhConstr);
1925 }
1926 return mapping;
1927 }
1928
1929 private final Pair<Scope,Scope> erroneousMapping = new Pair<Scope,Scope>(null, null);
1930
1931 /** Make an attributed null check tree.
1932 */
1933 public JCExpression makeNullCheck(JCExpression arg) {
1934 // optimization: X.this is never null; skip null check
1935 Name name = TreeInfo.name(arg);
1936 if (name == names._this || name == names._super) return arg;
1937
1938 JCTree.Tag optag = NULLCHK;
1939 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1940 tree.operator = syms.nullcheck;
1941 tree.type = arg.type;
1942 return tree;
1943 }
1944
1945 public void visitNewArray(JCNewArray tree) {
1946 Type owntype = types.createErrorType(tree.type);
1947 Type elemtype;
1948 if (tree.elemtype != null) {
1949 elemtype = attribType(tree.elemtype, env);
1950 chk.validate(tree.elemtype, env);
1951 owntype = elemtype;
1952 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1953 attribExpr(l.head, env, syms.intType);
1954 owntype = new ArrayType(owntype, syms.arrayClass);
1955 }
1956 } else {
1957 // we are seeing an untyped aggregate { ... }
1958 // this is allowed only if the prototype is an array
1959 if (pt.tag == ARRAY) {
1960 elemtype = types.elemtype(pt);
1961 } else {
1962 if (pt.tag != ERROR) {
1963 log.error(tree.pos(), "illegal.initializer.for.type",
1964 pt);
1965 }
1966 elemtype = types.createErrorType(pt);
1967 }
1968 }
1969 if (tree.elems != null) {
1970 attribExprs(tree.elems, env, elemtype);
1971 owntype = new ArrayType(elemtype, syms.arrayClass);
1972 }
1973 if (!types.isReifiable(elemtype))
1974 log.error(tree.pos(), "generic.array.creation");
1975 result = check(tree, owntype, VAL, pkind, pt);
1976 }
1977
1978 @Override
1979 public void visitLambda(JCLambda that) {
1980 throw new UnsupportedOperationException("Lambda expression not supported yet");
1981 }
1982
1983 @Override
1984 public void visitReference(JCMemberReference that) {
1985 throw new UnsupportedOperationException("Member references not supported yet");
1986 }
1987
1988 public void visitParens(JCParens tree) {
1989 Type owntype = attribTree(tree.expr, env, pkind, pt);
1990 result = check(tree, owntype, pkind, pkind, pt);
1991 Symbol sym = TreeInfo.symbol(tree);
1992 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1993 log.error(tree.pos(), "illegal.start.of.type");
1994 }
1995
1996 public void visitAssign(JCAssign tree) {
1997 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1998 Type capturedType = capture(owntype);
1999 attribExpr(tree.rhs, env, owntype);
2000 result = check(tree, capturedType, VAL, pkind, pt);
2001 }
2002
2003 public void visitAssignop(JCAssignOp tree) {
2004 // Attribute arguments.
2005 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
2006 Type operand = attribExpr(tree.rhs, env);
2007 // Find operator.
2008 Symbol operator = tree.operator = rs.resolveBinaryOperator(
2009 tree.pos(), tree.getTag().noAssignOp(), env,
2010 owntype, operand);
2011
2012 if (operator.kind == MTH &&
2013 !owntype.isErroneous() &&
2014 !operand.isErroneous()) {
2015 chk.checkOperator(tree.pos(),
2016 (OperatorSymbol)operator,
2017 tree.getTag().noAssignOp(),
2018 owntype,
2019 operand);
2020 chk.checkDivZero(tree.rhs.pos(), operator, operand);
2021 chk.checkCastable(tree.rhs.pos(),
2022 operator.type.getReturnType(),
2023 owntype);
2024 }
2025 result = check(tree, owntype, VAL, pkind, pt);
2026 }
2027
2028 public void visitUnary(JCUnary tree) {
2029 // Attribute arguments.
2030 Type argtype = (tree.getTag().isIncOrDecUnaryOp())
2031 ? attribTree(tree.arg, env, VAR, Type.noType)
2032 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
2033
2034 // Find operator.
2035 Symbol operator = tree.operator =
2036 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
2037
2038 Type owntype = types.createErrorType(tree.type);
2039 if (operator.kind == MTH &&
2040 !argtype.isErroneous()) {
2041 owntype = (tree.getTag().isIncOrDecUnaryOp())
2042 ? tree.arg.type
2043 : operator.type.getReturnType();
2044 int opc = ((OperatorSymbol)operator).opcode;
2045
2046 // If the argument is constant, fold it.
2047 if (argtype.constValue() != null) {
2048 Type ctype = cfolder.fold1(opc, argtype);
2049 if (ctype != null) {
2050 owntype = cfolder.coerce(ctype, owntype);
2051
2052 // Remove constant types from arguments to
2053 // conserve space. The parser will fold concatenations
2054 // of string literals; the code here also
2055 // gets rid of intermediate results when some of the
2056 // operands are constant identifiers.
2057 if (tree.arg.type.tsym == syms.stringType.tsym) {
2058 tree.arg.type = syms.stringType;
2059 }
2060 }
2061 }
2062 }
2063 result = check(tree, owntype, VAL, pkind, pt);
2064 }
2065
2066 public void visitBinary(JCBinary tree) {
2067 // Attribute arguments.
2068 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
2069 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
2070
2071 // Find operator.
2072 Symbol operator = tree.operator =
2073 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
2074
2075 Type owntype = types.createErrorType(tree.type);
2076 if (operator.kind == MTH &&
2077 !left.isErroneous() &&
2078 !right.isErroneous()) {
2079 owntype = operator.type.getReturnType();
2080 int opc = chk.checkOperator(tree.lhs.pos(),
2081 (OperatorSymbol)operator,
2082 tree.getTag(),
2083 left,
2084 right);
2085
2086 // If both arguments are constants, fold them.
2087 if (left.constValue() != null && right.constValue() != null) {
2088 Type ctype = cfolder.fold2(opc, left, right);
2089 if (ctype != null) {
2090 owntype = cfolder.coerce(ctype, owntype);
2091
2092 // Remove constant types from arguments to
2093 // conserve space. The parser will fold concatenations
2094 // of string literals; the code here also
2095 // gets rid of intermediate results when some of the
2096 // operands are constant identifiers.
2097 if (tree.lhs.type.tsym == syms.stringType.tsym) {
2098 tree.lhs.type = syms.stringType;
2099 }
2100 if (tree.rhs.type.tsym == syms.stringType.tsym) {
2101 tree.rhs.type = syms.stringType;
2102 }
2103 }
2104 }
2105
2106 // Check that argument types of a reference ==, != are
2107 // castable to each other, (JLS???).
2108 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
2109 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
2110 log.error(tree.pos(), "incomparable.types", left, right);
2111 }
2112 }
2113
2114 chk.checkDivZero(tree.rhs.pos(), operator, right);
2115 }
2116 result = check(tree, owntype, VAL, pkind, pt);
2117 }
2118
2119 public void visitTypeCast(JCTypeCast tree) {
2120 Type clazztype = attribType(tree.clazz, env);
2121 chk.validate(tree.clazz, env, false);
2122 //a fresh environment is required for 292 inference to work properly ---
2123 //see Infer.instantiatePolymorphicSignatureInstance()
2124 Env<AttrContext> localEnv = env.dup(tree);
2125 Type exprtype = attribExpr(tree.expr, localEnv, Infer.anyPoly);
2126 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2127 if (exprtype.constValue() != null)
2128 owntype = cfolder.coerce(exprtype, owntype);
2129 result = check(tree, capture(owntype), VAL, pkind, pt);
2130 }
2131
2132 public void visitTypeTest(JCInstanceOf tree) {
2133 Type exprtype = chk.checkNullOrRefType(
2134 tree.expr.pos(), attribExpr(tree.expr, env));
2135 Type clazztype = chk.checkReifiableReferenceType(
2136 tree.clazz.pos(), attribType(tree.clazz, env));
2137 chk.validate(tree.clazz, env, false);
2138 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2139 result = check(tree, syms.booleanType, VAL, pkind, pt);
2140 }
2141
2142 public void visitIndexed(JCArrayAccess tree) {
2143 Type owntype = types.createErrorType(tree.type);
2144 Type atype = attribExpr(tree.indexed, env);
2145 attribExpr(tree.index, env, syms.intType);
2146 if (types.isArray(atype))
2147 owntype = types.elemtype(atype);
2148 else if (atype.tag != ERROR)
2149 log.error(tree.pos(), "array.req.but.found", atype);
2150 if ((pkind & VAR) == 0) owntype = capture(owntype);
2151 result = check(tree, owntype, VAR, pkind, pt);
2152 }
2153
2154 public void visitIdent(JCIdent tree) {
2155 Symbol sym;
2156 boolean varArgs = false;
2157
2158 // Find symbol
2159 if (pt.tag == METHOD || pt.tag == FORALL) {
2160 // If we are looking for a method, the prototype `pt' will be a
2161 // method type with the type of the call's arguments as parameters.
2162 env.info.varArgs = false;
2163 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
2164 varArgs = env.info.varArgs;
2165 } else if (tree.sym != null && tree.sym.kind != VAR) {
2166 sym = tree.sym;
2167 } else {
2168 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
2169 }
2170 tree.sym = sym;
2171
2172 // (1) Also find the environment current for the class where
2173 // sym is defined (`symEnv').
2174 // Only for pre-tiger versions (1.4 and earlier):
2175 // (2) Also determine whether we access symbol out of an anonymous
2176 // class in a this or super call. This is illegal for instance
2177 // members since such classes don't carry a this$n link.
2178 // (`noOuterThisPath').
2179 Env<AttrContext> symEnv = env;
2180 boolean noOuterThisPath = false;
2181 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
2182 (sym.kind & (VAR | MTH | TYP)) != 0 &&
2183 sym.owner.kind == TYP &&
2184 tree.name != names._this && tree.name != names._super) {
2185
2186 // Find environment in which identifier is defined.
2187 while (symEnv.outer != null &&
2188 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
2189 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
2190 noOuterThisPath = !allowAnonOuterThis;
2191 symEnv = symEnv.outer;
2192 }
2193 }
2194
2195 // If symbol is a variable, ...
2196 if (sym.kind == VAR) {
2197 VarSymbol v = (VarSymbol)sym;
2198
2199 // ..., evaluate its initializer, if it has one, and check for
2200 // illegal forward reference.
2201 checkInit(tree, env, v, false);
2202
2203 // If symbol is a local variable accessed from an embedded
2204 // inner class check that it is final.
2205 if (v.owner.kind == MTH &&
2206 v.owner != env.info.scope.owner &&
2207 (v.flags_field & FINAL) == 0) {
2208 log.error(tree.pos(),
2209 "local.var.accessed.from.icls.needs.final",
2210 v);
2211 }
2212
2213 // If we are expecting a variable (as opposed to a value), check
2214 // that the variable is assignable in the current environment.
2215 if (pkind == VAR)
2216 checkAssignable(tree.pos(), v, null, env);
2217 }
2218
2219 // In a constructor body,
2220 // if symbol is a field or instance method, check that it is
2221 // not accessed before the supertype constructor is called.
2222 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
2223 (sym.kind & (VAR | MTH)) != 0 &&
2224 sym.owner.kind == TYP &&
2225 (sym.flags() & STATIC) == 0) {
2226 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
2227 }
2228 Env<AttrContext> env1 = env;
2229 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
2230 // If the found symbol is inaccessible, then it is
2231 // accessed through an enclosing instance. Locate this
2232 // enclosing instance:
2233 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
2234 env1 = env1.outer;
2235 }
2236 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
2237 }
2238
2239 public void visitSelect(JCFieldAccess tree) {
2240 // Determine the expected kind of the qualifier expression.
2241 int skind = 0;
2242 if (tree.name == names._this || tree.name == names._super ||
2243 tree.name == names._class)
2244 {
2245 skind = TYP;
2246 } else {
2247 if ((pkind & PCK) != 0) skind = skind | PCK;
2248 if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
2249 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
2250 }
2251
2252 // Attribute the qualifier expression, and determine its symbol (if any).
2253 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
2254 if ((pkind & (PCK | TYP)) == 0)
2255 site = capture(site); // Capture field access
2256
2257 // don't allow T.class T[].class, etc
2258 if (skind == TYP) {
2259 Type elt = site;
2260 while (elt.tag == ARRAY)
2261 elt = ((ArrayType)elt).elemtype;
2262 if (elt.tag == TYPEVAR) {
2263 log.error(tree.pos(), "type.var.cant.be.deref");
2264 result = types.createErrorType(tree.type);
2265 return;
2266 }
2267 }
2268
2269 // If qualifier symbol is a type or `super', assert `selectSuper'
2270 // for the selection. This is relevant for determining whether
2271 // protected symbols are accessible.
2272 Symbol sitesym = TreeInfo.symbol(tree.selected);
2273 boolean selectSuperPrev = env.info.selectSuper;
2274 env.info.selectSuper =
2275 sitesym != null &&
2276 sitesym.name == names._super;
2277
2278 // If selected expression is polymorphic, strip
2279 // type parameters and remember in env.info.tvars, so that
2280 // they can be added later (in Attr.checkId and Infer.instantiateMethod).
2281 if (tree.selected.type.tag == FORALL) {
2282 ForAll pstype = (ForAll)tree.selected.type;
2283 env.info.tvars = pstype.tvars;
2284 site = tree.selected.type = pstype.qtype;
2285 }
2286
2287 // Determine the symbol represented by the selection.
2288 env.info.varArgs = false;
2289 Symbol sym = selectSym(tree, sitesym, site, env, pt, pkind);
2290 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
2291 site = capture(site);
2292 sym = selectSym(tree, sitesym, site, env, pt, pkind);
2293 }
2294 boolean varArgs = env.info.varArgs;
2295 tree.sym = sym;
2296
2297 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
2298 while (site.tag == TYPEVAR) site = site.getUpperBound();
2299 site = capture(site);
2300 }
2301
2302 // If that symbol is a variable, ...
2303 if (sym.kind == VAR) {
2304 VarSymbol v = (VarSymbol)sym;
2305
2306 // ..., evaluate its initializer, if it has one, and check for
2307 // illegal forward reference.
2308 checkInit(tree, env, v, true);
2309
2310 // If we are expecting a variable (as opposed to a value), check
2311 // that the variable is assignable in the current environment.
2312 if (pkind == VAR)
2313 checkAssignable(tree.pos(), v, tree.selected, env);
2314 }
2315
2316 if (sitesym != null &&
2317 sitesym.kind == VAR &&
2318 ((VarSymbol)sitesym).isResourceVariable() &&
2319 sym.kind == MTH &&
2320 sym.name.equals(names.close) &&
2321 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
2322 env.info.lint.isEnabled(LintCategory.TRY)) {
2323 log.warning(LintCategory.TRY, tree, "try.explicit.close.call");
2324 }
2325
2326 // Disallow selecting a type from an expression
2327 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
2328 tree.type = check(tree.selected, pt,
2329 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
2330 }
2331
2332 if (isType(sitesym)) {
2333 if (sym.name == names._this) {
2334 // If `C' is the currently compiled class, check that
2335 // C.this' does not appear in a call to a super(...)
2336 if (env.info.isSelfCall &&
2337 site.tsym == env.enclClass.sym) {
2338 chk.earlyRefError(tree.pos(), sym);
2339 }
2340 } else {
2341 // Check if type-qualified fields or methods are static (JLS)
2342 if ((sym.flags() & STATIC) == 0 &&
2343 sym.name != names._super &&
2344 (sym.kind == VAR || sym.kind == MTH)) {
2345 rs.access(rs.new StaticError(sym),
2346 tree.pos(), site, sym.name, true);
2347 }
2348 }
2349 } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
2350 // If the qualified item is not a type and the selected item is static, report
2351 // a warning. Make allowance for the class of an array type e.g. Object[].class)
2352 chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
2353 }
2354
2355 // If we are selecting an instance member via a `super', ...
2356 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
2357
2358 // Check that super-qualified symbols are not abstract (JLS)
2359 rs.checkNonAbstract(tree.pos(), sym);
2360
2361 if (site.isRaw()) {
2362 // Determine argument types for site.
2363 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
2364 if (site1 != null) site = site1;
2365 }
2366 }
2367
2368 env.info.selectSuper = selectSuperPrev;
2369 result = checkId(tree, site, sym, env, pkind, pt, varArgs);
2370 env.info.tvars = List.nil();
2371 }
2372 //where
2373 /** Determine symbol referenced by a Select expression,
2374 *
2375 * @param tree The select tree.
2376 * @param site The type of the selected expression,
2377 * @param env The current environment.
2378 * @param pt The current prototype.
2379 * @param pkind The expected kind(s) of the Select expression.
2380 */
2381 private Symbol selectSym(JCFieldAccess tree,
2382 Type site,
2383 Env<AttrContext> env,
2384 Type pt,
2385 int pkind) {
2386 return selectSym(tree, site.tsym, site, env, pt, pkind);
2387 }
2388 private Symbol selectSym(JCFieldAccess tree,
2389 Symbol location,
2390 Type site,
2391 Env<AttrContext> env,
2392 Type pt,
2393 int pkind) {
2394 DiagnosticPosition pos = tree.pos();
2395 Name name = tree.name;
2396 switch (site.tag) {
2397 case PACKAGE:
2398 return rs.access(
2399 rs.findIdentInPackage(env, site.tsym, name, pkind),
2400 pos, location, site, name, true);
2401 case ARRAY:
2402 case CLASS:
2403 if (pt.tag == METHOD || pt.tag == FORALL) {
2404 return rs.resolveQualifiedMethod(
2405 pos, env, location, site, name, pt.getParameterTypes(), pt.getTypeArguments());
2406 } else if (name == names._this || name == names._super) {
2407 return rs.resolveSelf(pos, env, site.tsym, name);
2408 } else if (name == names._class) {
2409 // In this case, we have already made sure in
2410 // visitSelect that qualifier expression is a type.
2411 Type t = syms.classType;
2412 List<Type> typeargs = allowGenerics
2413 ? List.of(types.erasure(site))
2414 : List.<Type>nil();
2415 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
2416 return new VarSymbol(
2417 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2418 } else {
2419 // We are seeing a plain identifier as selector.
2420 Symbol sym = rs.findIdentInType(env, site, name, pkind);
2421 if ((pkind & ERRONEOUS) == 0)
2422 sym = rs.access(sym, pos, location, site, name, true);
2423 return sym;
2424 }
2425 case WILDCARD:
2426 throw new AssertionError(tree);
2427 case TYPEVAR:
2428 // Normally, site.getUpperBound() shouldn't be null.
2429 // It should only happen during memberEnter/attribBase
2430 // when determining the super type which *must* beac
2431 // done before attributing the type variables. In
2432 // other words, we are seeing this illegal program:
2433 // class B<T> extends A<T.foo> {}
2434 Symbol sym = (site.getUpperBound() != null)
2435 ? selectSym(tree, location, capture(site.getUpperBound()), env, pt, pkind)
2436 : null;
2437 if (sym == null) {
2438 log.error(pos, "type.var.cant.be.deref");
2439 return syms.errSymbol;
2440 } else {
2441 Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
2442 rs.new AccessError(env, site, sym) :
2443 sym;
2444 rs.access(sym2, pos, location, site, name, true);
2445 return sym;
2446 }
2447 case ERROR:
2448 // preserve identifier names through errors
2449 return types.createErrorType(name, site.tsym, site).tsym;
2450 default:
2451 // The qualifier expression is of a primitive type -- only
2452 // .class is allowed for these.
2453 if (name == names._class) {
2454 // In this case, we have already made sure in Select that
2455 // qualifier expression is a type.
2456 Type t = syms.classType;
2457 Type arg = types.boxedClass(site).type;
2458 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2459 return new VarSymbol(
2460 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2461 } else {
2462 log.error(pos, "cant.deref", site);
2463 return syms.errSymbol;
2464 }
2465 }
2466 }
2467
2468 /** Determine type of identifier or select expression and check that
2469 * (1) the referenced symbol is not deprecated
2470 * (2) the symbol's type is safe (@see checkSafe)
2471 * (3) if symbol is a variable, check that its type and kind are
2472 * compatible with the prototype and protokind.
2473 * (4) if symbol is an instance field of a raw type,
2474 * which is being assigned to, issue an unchecked warning if its
2475 * type changes under erasure.
2476 * (5) if symbol is an instance method of a raw type, issue an
2477 * unchecked warning if its argument types change under erasure.
2478 * If checks succeed:
2479 * If symbol is a constant, return its constant type
2480 * else if symbol is a method, return its result type
2481 * otherwise return its type.
2482 * Otherwise return errType.
2483 *
2484 * @param tree The syntax tree representing the identifier
2485 * @param site If this is a select, the type of the selected
2486 * expression, otherwise the type of the current class.
2487 * @param sym The symbol representing the identifier.
2488 * @param env The current environment.
2489 * @param pkind The set of expected kinds.
2490 * @param pt The expected type.
2491 */
2492 Type checkId(JCTree tree,
2493 Type site,
2494 Symbol sym,
2495 Env<AttrContext> env,
2496 int pkind,
2497 Type pt,
2498 boolean useVarargs) {
2499 if (pt.isErroneous()) return types.createErrorType(site);
2500 Type owntype; // The computed type of this identifier occurrence.
2501 switch (sym.kind) {
2502 case TYP:
2503 // For types, the computed type equals the symbol's type,
2504 // except for two situations:
2505 owntype = sym.type;
2506 if (owntype.tag == CLASS) {
2507 Type ownOuter = owntype.getEnclosingType();
2508
2509 // (a) If the symbol's type is parameterized, erase it
2510 // because no type parameters were given.
2511 // We recover generic outer type later in visitTypeApply.
2512 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2513 owntype = types.erasure(owntype);
2514 }
2515
2516 // (b) If the symbol's type is an inner class, then
2517 // we have to interpret its outer type as a superclass
2518 // of the site type. Example:
2519 //
2520 // class Tree<A> { class Visitor { ... } }
2521 // class PointTree extends Tree<Point> { ... }
2522 // ...PointTree.Visitor...
2523 //
2524 // Then the type of the last expression above is
2525 // Tree<Point>.Visitor.
2526 else if (ownOuter.tag == CLASS && site != ownOuter) {
2527 Type normOuter = site;
2528 if (normOuter.tag == CLASS)
2529 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2530 if (normOuter == null) // perhaps from an import
2531 normOuter = types.erasure(ownOuter);
2532 if (normOuter != ownOuter)
2533 owntype = new ClassType(
2534 normOuter, List.<Type>nil(), owntype.tsym);
2535 }
2536 }
2537 break;
2538 case VAR:
2539 VarSymbol v = (VarSymbol)sym;
2540 // Test (4): if symbol is an instance field of a raw type,
2541 // which is being assigned to, issue an unchecked warning if
2542 // its type changes under erasure.
2543 if (allowGenerics &&
2544 pkind == VAR &&
2545 v.owner.kind == TYP &&
2546 (v.flags() & STATIC) == 0 &&
2547 (site.tag == CLASS || site.tag == TYPEVAR)) {
2548 Type s = types.asOuterSuper(site, v.owner);
2549 if (s != null &&
2550 s.isRaw() &&
2551 !types.isSameType(v.type, v.erasure(types))) {
2552 chk.warnUnchecked(tree.pos(),
2553 "unchecked.assign.to.var",
2554 v, s);
2555 }
2556 }
2557 // The computed type of a variable is the type of the
2558 // variable symbol, taken as a member of the site type.
2559 owntype = (sym.owner.kind == TYP &&
2560 sym.name != names._this && sym.name != names._super)
2561 ? types.memberType(site, sym)
2562 : sym.type;
2563
2564 if (env.info.tvars.nonEmpty()) {
2565 Type owntype1 = new ForAll(env.info.tvars, owntype);
2566 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2567 if (!owntype.contains(l.head)) {
2568 log.error(tree.pos(), "undetermined.type", owntype1);
2569 owntype1 = types.createErrorType(owntype1);
2570 }
2571 owntype = owntype1;
2572 }
2573
2574 // If the variable is a constant, record constant value in
2575 // computed type.
2576 if (v.getConstValue() != null && isStaticReference(tree))
2577 owntype = owntype.constType(v.getConstValue());
2578
2579 if (pkind == VAL) {
2580 owntype = capture(owntype); // capture "names as expressions"
2581 }
2582 break;
2583 case MTH: {
2584 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2585 owntype = checkMethod(site, sym, env, app.args,
2586 pt.getParameterTypes(), pt.getTypeArguments(),
2587 env.info.varArgs);
2588 break;
2589 }
2590 case PCK: case ERR:
2591 owntype = sym.type;
2592 break;
2593 default:
2594 throw new AssertionError("unexpected kind: " + sym.kind +
2595 " in tree " + tree);
2596 }
2597
2598 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2599 // (for constructors, the error was given when the constructor was
2600 // resolved)
2601
2602 if (sym.name != names.init) {
2603 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
2604 chk.checkSunAPI(tree.pos(), sym);
2605 }
2606
2607 // Test (3): if symbol is a variable, check that its type and
2608 // kind are compatible with the prototype and protokind.
2609 return check(tree, owntype, sym.kind, pkind, pt);
2610 }
2611
2612 /** Check that variable is initialized and evaluate the variable's
2613 * initializer, if not yet done. Also check that variable is not
2614 * referenced before it is defined.
2615 * @param tree The tree making up the variable reference.
2616 * @param env The current environment.
2617 * @param v The variable's symbol.
2618 */
2619 private void checkInit(JCTree tree,
2620 Env<AttrContext> env,
2621 VarSymbol v,
2622 boolean onlyWarning) {
2623 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2624 // tree.pos + " " + v.pos + " " +
2625 // Resolve.isStatic(env));//DEBUG
2626
2627 // A forward reference is diagnosed if the declaration position
2628 // of the variable is greater than the current tree position
2629 // and the tree and variable definition occur in the same class
2630 // definition. Note that writes don't count as references.
2631 // This check applies only to class and instance
2632 // variables. Local variables follow different scope rules,
2633 // and are subject to definite assignment checking.
2634 if ((env.info.enclVar == v || v.pos > tree.pos) &&
2635 v.owner.kind == TYP &&
2636 canOwnInitializer(env.info.scope.owner) &&
2637 v.owner == env.info.scope.owner.enclClass() &&
2638 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2639 (!env.tree.hasTag(ASSIGN) ||
2640 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2641 String suffix = (env.info.enclVar == v) ?
2642 "self.ref" : "forward.ref";
2643 if (!onlyWarning || isStaticEnumField(v)) {
2644 log.error(tree.pos(), "illegal." + suffix);
2645 } else if (useBeforeDeclarationWarning) {
2646 log.warning(tree.pos(), suffix, v);
2647 }
2648 }
2649
2650 v.getConstValue(); // ensure initializer is evaluated
2651
2652 checkEnumInitializer(tree, env, v);
2653 }
2654
2655 /**
2656 * Check for illegal references to static members of enum. In
2657 * an enum type, constructors and initializers may not
2658 * reference its static members unless they are constant.
2659 *
2660 * @param tree The tree making up the variable reference.
2661 * @param env The current environment.
2662 * @param v The variable's symbol.
2663 * @jls section 8.9 Enums
2664 */
2665 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2666 // JLS:
2667 //
2668 // "It is a compile-time error to reference a static field
2669 // of an enum type that is not a compile-time constant
2670 // (15.28) from constructors, instance initializer blocks,
2671 // or instance variable initializer expressions of that
2672 // type. It is a compile-time error for the constructors,
2673 // instance initializer blocks, or instance variable
2674 // initializer expressions of an enum constant e to refer
2675 // to itself or to an enum constant of the same type that
2676 // is declared to the right of e."
2677 if (isStaticEnumField(v)) {
2678 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2679
2680 if (enclClass == null || enclClass.owner == null)
2681 return;
2682
2683 // See if the enclosing class is the enum (or a
2684 // subclass thereof) declaring v. If not, this
2685 // reference is OK.
2686 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2687 return;
2688
2689 // If the reference isn't from an initializer, then
2690 // the reference is OK.
2691 if (!Resolve.isInitializer(env))
2692 return;
2693
2694 log.error(tree.pos(), "illegal.enum.static.ref");
2695 }
2696 }
2697
2698 /** Is the given symbol a static, non-constant field of an Enum?
2699 * Note: enum literals should not be regarded as such
2700 */
2701 private boolean isStaticEnumField(VarSymbol v) {
2702 return Flags.isEnum(v.owner) &&
2703 Flags.isStatic(v) &&
2704 !Flags.isConstant(v) &&
2705 v.name != names._class;
2706 }
2707
2708 /** Can the given symbol be the owner of code which forms part
2709 * if class initialization? This is the case if the symbol is
2710 * a type or field, or if the symbol is the synthetic method.
2711 * owning a block.
2712 */
2713 private boolean canOwnInitializer(Symbol sym) {
2714 return
2715 (sym.kind & (VAR | TYP)) != 0 ||
2716 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2717 }
2718
2719 Warner noteWarner = new Warner();
2720
2721 /**
2722 * Check that method arguments conform to its instantation.
2723 **/
2724 public Type checkMethod(Type site,
2725 Symbol sym,
2726 Env<AttrContext> env,
2727 final List<JCExpression> argtrees,
2728 List<Type> argtypes,
2729 List<Type> typeargtypes,
2730 boolean useVarargs) {
2731 // Test (5): if symbol is an instance method of a raw type, issue
2732 // an unchecked warning if its argument types change under erasure.
2733 if (allowGenerics &&
2734 (sym.flags() & STATIC) == 0 &&
2735 (site.tag == CLASS || site.tag == TYPEVAR)) {
2736 Type s = types.asOuterSuper(site, sym.owner);
2737 if (s != null && s.isRaw() &&
2738 !types.isSameTypes(sym.type.getParameterTypes(),
2739 sym.erasure(types).getParameterTypes())) {
2740 chk.warnUnchecked(env.tree.pos(),
2741 "unchecked.call.mbr.of.raw.type",
2742 sym, s);
2743 }
2744 }
2745
2746 // Compute the identifier's instantiated type.
2747 // For methods, we need to compute the instance type by
2748 // Resolve.instantiate from the symbol's type as well as
2749 // any type arguments and value arguments.
2750 noteWarner.clear();
2751 Type owntype = rs.instantiate(env,
2752 site,
2753 sym,
2754 argtypes,
2755 typeargtypes,
2756 true,
2757 useVarargs,
2758 noteWarner);
2759 boolean warned = noteWarner.hasNonSilentLint(LintCategory.UNCHECKED);
2760
2761 // If this fails, something went wrong; we should not have
2762 // found the identifier in the first place.
2763 if (owntype == null) {
2764 if (!pt.isErroneous())
2765 log.error(env.tree.pos(),
2766 "internal.error.cant.instantiate",
2767 sym, site,
2768 Type.toString(pt.getParameterTypes()));
2769 owntype = types.createErrorType(site);
2770 } else {
2771 // System.out.println("call : " + env.tree);
2772 // System.out.println("method : " + owntype);
2773 // System.out.println("actuals: " + argtypes);
2774 List<Type> formals = owntype.getParameterTypes();
2775 Type last = useVarargs ? formals.last() : null;
2776 if (sym.name==names.init &&
2777 sym.owner == syms.enumSym)
2778 formals = formals.tail.tail;
2779 List<JCExpression> args = argtrees;
2780 while (formals.head != last) {
2781 JCTree arg = args.head;
2782 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2783 assertConvertible(arg, arg.type, formals.head, warn);
2784 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED);
2785 args = args.tail;
2786 formals = formals.tail;
2787 }
2788 if (useVarargs) {
2789 Type varArg = types.elemtype(last);
2790 while (args.tail != null) {
2791 JCTree arg = args.head;
2792 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2793 assertConvertible(arg, arg.type, varArg, warn);
2794 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED);
2795 args = args.tail;
2796 }
2797 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2798 // non-varargs call to varargs method
2799 Type varParam = owntype.getParameterTypes().last();
2800 Type lastArg = argtypes.last();
2801 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2802 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2803 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2804 types.elemtype(varParam),
2805 varParam);
2806 }
2807
2808 if (warned && sym.type.tag == FORALL) {
2809 chk.warnUnchecked(env.tree.pos(),
2810 "unchecked.meth.invocation.applied",
2811 kindName(sym),
2812 sym.name,
2813 rs.methodArguments(sym.type.getParameterTypes()),
2814 rs.methodArguments(argtypes),
2815 kindName(sym.location()),
2816 sym.location());
2817 owntype = new MethodType(owntype.getParameterTypes(),
2818 types.erasure(owntype.getReturnType()),
2819 types.erasure(owntype.getThrownTypes()),
2820 syms.methodClass);
2821 }
2822 if (useVarargs) {
2823 JCTree tree = env.tree;
2824 Type argtype = owntype.getParameterTypes().last();
2825 if (owntype.getReturnType().tag != FORALL || warned) {
2826 chk.checkVararg(env.tree.pos(), owntype.getParameterTypes(), sym);
2827 }
2828 Type elemtype = types.elemtype(argtype);
2829 switch (tree.getTag()) {
2830 case APPLY:
2831 ((JCMethodInvocation) tree).varargsElement = elemtype;
2832 break;
2833 case NEWCLASS:
2834 ((JCNewClass) tree).varargsElement = elemtype;
2835 break;
2836 default:
2837 throw new AssertionError(""+tree);
2838 }
2839 }
2840 }
2841 return owntype;
2842 }
2843
2844 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2845 if (types.isConvertible(actual, formal, warn))
2846 return;
2847
2848 if (formal.isCompound()
2849 && types.isSubtype(actual, types.supertype(formal))
2850 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2851 return;
2852
2853 if (false) {
2854 // TODO: make assertConvertible work
2855 chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal);
2856 throw new AssertionError("Tree: " + tree
2857 + " actual:" + actual
2858 + " formal: " + formal);
2859 }
2860 }
2861
2862 public void visitLiteral(JCLiteral tree) {
2863 result = check(
2864 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2865 }
2866 //where
2867 /** Return the type of a literal with given type tag.
2868 */
2869 Type litType(int tag) {
2870 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2871 }
2872
2873 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2874 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2875 }
2876
2877 public void visitTypeArray(JCArrayTypeTree tree) {
2878 Type etype = attribType(tree.elemtype, env);
2879 Type type = new ArrayType(etype, syms.arrayClass);
2880 result = check(tree, type, TYP, pkind, pt);
2881 }
2882
2883 /** Visitor method for parameterized types.
2884 * Bound checking is left until later, since types are attributed
2885 * before supertype structure is completely known
2886 */
2887 public void visitTypeApply(JCTypeApply tree) {
2888 Type owntype = types.createErrorType(tree.type);
2889
2890 // Attribute functor part of application and make sure it's a class.
2891 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2892
2893 // Attribute type parameters
2894 List<Type> actuals = attribTypes(tree.arguments, env);
2895
2896 if (clazztype.tag == CLASS) {
2897 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2898 if (actuals.isEmpty()) //diamond
2899 actuals = formals;
2900
2901 if (actuals.length() == formals.length()) {
2902 List<Type> a = actuals;
2903 List<Type> f = formals;
2904 while (a.nonEmpty()) {
2905 a.head = a.head.withTypeVar(f.head);
2906 a = a.tail;
2907 f = f.tail;
2908 }
2909 // Compute the proper generic outer
2910 Type clazzOuter = clazztype.getEnclosingType();
2911 if (clazzOuter.tag == CLASS) {
2912 Type site;
2913 JCExpression clazz = TreeInfo.typeIn(tree.clazz);
2914 if (clazz.hasTag(IDENT)) {
2915 site = env.enclClass.sym.type;
2916 } else if (clazz.hasTag(SELECT)) {
2917 site = ((JCFieldAccess) clazz).selected.type;
2918 } else throw new AssertionError(""+tree);
2919 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2920 if (site.tag == CLASS)
2921 site = types.asOuterSuper(site, clazzOuter.tsym);
2922 if (site == null)
2923 site = types.erasure(clazzOuter);
2924 clazzOuter = site;
2925 }
2926 }
2927 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2928 } else {
2929 if (formals.length() != 0) {
2930 log.error(tree.pos(), "wrong.number.type.args",
2931 Integer.toString(formals.length()));
2932 } else {
2933 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2934 }
2935 owntype = types.createErrorType(tree.type);
2936 }
2937 }
2938 result = check(tree, owntype, TYP, pkind, pt);
2939 }
2940
2941 public void visitTypeUnion(JCTypeUnion tree) {
2942 ListBuffer<Type> multicatchTypes = ListBuffer.lb();
2943 ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
2944 for (JCExpression typeTree : tree.alternatives) {
2945 Type ctype = attribType(typeTree, env);
2946 ctype = chk.checkType(typeTree.pos(),
2947 chk.checkClassType(typeTree.pos(), ctype),
2948 syms.throwableType);
2949 if (!ctype.isErroneous()) {
2950 //check that alternatives of a union type are pairwise
2951 //unrelated w.r.t. subtyping
2952 if (chk.intersects(ctype, multicatchTypes.toList())) {
2953 for (Type t : multicatchTypes) {
2954 boolean sub = types.isSubtype(ctype, t);
2955 boolean sup = types.isSubtype(t, ctype);
2956 if (sub || sup) {
2957 //assume 'a' <: 'b'
2958 Type a = sub ? ctype : t;
2959 Type b = sub ? t : ctype;
2960 log.error(typeTree.pos(), "multicatch.types.must.be.disjoint", a, b);
2961 }
2962 }
2963 }
2964 multicatchTypes.append(ctype);
2965 if (all_multicatchTypes != null)
2966 all_multicatchTypes.append(ctype);
2967 } else {
2968 if (all_multicatchTypes == null) {
2969 all_multicatchTypes = ListBuffer.lb();
2970 all_multicatchTypes.appendList(multicatchTypes);
2971 }
2972 all_multicatchTypes.append(ctype);
2973 }
2974 }
2975 Type t = check(tree, types.lub(multicatchTypes.toList()), TYP, pkind, pt);
2976 if (t.tag == CLASS) {
2977 List<Type> alternatives =
2978 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
2979 t = new UnionClassType((ClassType) t, alternatives);
2980 }
2981 tree.type = result = t;
2982 }
2983
2984 public void visitTypeParameter(JCTypeParameter tree) {
2985 TypeVar a = (TypeVar)tree.type;
2986 Set<Type> boundSet = new HashSet<Type>();
2987 if (a.bound.isErroneous())
2988 return;
2989 List<Type> bs = types.getBounds(a);
2990 if (tree.bounds.nonEmpty()) {
2991 // accept class or interface or typevar as first bound.
2992 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2993 boundSet.add(types.erasure(b));
2994 if (b.isErroneous()) {
2995 a.bound = b;
2996 }
2997 else if (b.tag == TYPEVAR) {
2998 // if first bound was a typevar, do not accept further bounds.
2999 if (tree.bounds.tail.nonEmpty()) {
3000 log.error(tree.bounds.tail.head.pos(),
3001 "type.var.may.not.be.followed.by.other.bounds");
3002 tree.bounds = List.of(tree.bounds.head);
3003 a.bound = bs.head;
3004 }
3005 } else {
3006 // if first bound was a class or interface, accept only interfaces
3007 // as further bounds.
3008 for (JCExpression bound : tree.bounds.tail) {
3009 bs = bs.tail;
3010 Type i = checkBase(bs.head, bound, env, false, true, false);
3011 if (i.isErroneous())
3012 a.bound = i;
3013 else if (i.tag == CLASS)
3014 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
3015 }
3016 }
3017 }
3018 bs = types.getBounds(a);
3019
3020 // in case of multiple bounds ...
3021 if (bs.length() > 1) {
3022 // ... the variable's bound is a class type flagged COMPOUND
3023 // (see comment for TypeVar.bound).
3024 // In this case, generate a class tree that represents the
3025 // bound class, ...
3026 JCExpression extending;
3027 List<JCExpression> implementing;
3028 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
3029 extending = tree.bounds.head;
3030 implementing = tree.bounds.tail;
3031 } else {
3032 extending = null;
3033 implementing = tree.bounds;
3034 }
3035 JCClassDecl cd = make.at(tree.pos).ClassDef(
3036 make.Modifiers(PUBLIC | ABSTRACT),
3037 tree.name, List.<JCTypeParameter>nil(),
3038 extending, implementing, List.<JCTree>nil());
3039
3040 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
3041 Assert.check((c.flags() & COMPOUND) != 0);
3042 cd.sym = c;
3043 c.sourcefile = env.toplevel.sourcefile;
3044
3045 // ... and attribute the bound class
3046 c.flags_field |= UNATTRIBUTED;
3047 Env<AttrContext> cenv = enter.classEnv(cd, env);
3048 enter.typeEnvs.put(c, cenv);
3049 }
3050 }
3051
3052
3053 public void visitWildcard(JCWildcard tree) {
3054 //- System.err.println("visitWildcard("+tree+");");//DEBUG
3055 Type type = (tree.kind.kind == BoundKind.UNBOUND)
3056 ? syms.objectType
3057 : attribType(tree.inner, env);
3058 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
3059 tree.kind.kind,
3060 syms.boundClass),
3061 TYP, pkind, pt);
3062 }
3063
3064 public void visitAnnotation(JCAnnotation tree) {
3065 log.error(tree.pos(), "annotation.not.valid.for.type", pt);
3066 result = tree.type = syms.errType;
3067 }
3068
3069 public void visitErroneous(JCErroneous tree) {
3070 if (tree.errs != null)
3071 for (JCTree err : tree.errs)
3072 attribTree(err, env, ERR, pt);
3073 result = tree.type = syms.errType;
3074 }
3075
3076 /** Default visitor method for all other trees.
3077 */
3078 public void visitTree(JCTree tree) {
3079 throw new AssertionError();
3080 }
3081
3082 /**
3083 * Attribute an env for either a top level tree or class declaration.
3084 */
3085 public void attrib(Env<AttrContext> env) {
3086 if (env.tree.hasTag(TOPLEVEL))
3087 attribTopLevel(env);
3088 else
3089 attribClass(env.tree.pos(), env.enclClass.sym);
3090 }
3091
3092 /**
3093 * Attribute a top level tree. These trees are encountered when the
3094 * package declaration has annotations.
3095 */
3096 public void attribTopLevel(Env<AttrContext> env) {
3097 JCCompilationUnit toplevel = env.toplevel;
3098 try {
3099 annotate.flush();
3100 chk.validateAnnotations(toplevel.packageAnnotations, toplevel.packge);
3101 } catch (CompletionFailure ex) {
3102 chk.completionError(toplevel.pos(), ex);
3103 }
3104 }
3105
3106 /** Main method: attribute class definition associated with given class symbol.
3107 * reporting completion failures at the given position.
3108 * @param pos The source position at which completion errors are to be
3109 * reported.
3110 * @param c The class symbol whose definition will be attributed.
3111 */
3112 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
3113 try {
3114 annotate.flush();
3115 attribClass(c);
3116 } catch (CompletionFailure ex) {
3117 chk.completionError(pos, ex);
3118 }
3119 }
3120
3121 /** Attribute class definition associated with given class symbol.
3122 * @param c The class symbol whose definition will be attributed.
3123 */
3124 void attribClass(ClassSymbol c) throws CompletionFailure {
3125 if (c.type.tag == ERROR) return;
3126
3127 // Check for cycles in the inheritance graph, which can arise from
3128 // ill-formed class files.
3129 chk.checkNonCyclic(null, c.type);
3130
3131 Type st = types.supertype(c.type);
3132 if ((c.flags_field & Flags.COMPOUND) == 0) {
3133 // First, attribute superclass.
3134 if (st.tag == CLASS)
3135 attribClass((ClassSymbol)st.tsym);
3136
3137 // Next attribute owner, if it is a class.
3138 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
3139 attribClass((ClassSymbol)c.owner);
3140 }
3141
3142 // The previous operations might have attributed the current class
3143 // if there was a cycle. So we test first whether the class is still
3144 // UNATTRIBUTED.
3145 if ((c.flags_field & UNATTRIBUTED) != 0) {
3146 c.flags_field &= ~UNATTRIBUTED;
3147
3148 // Get environment current at the point of class definition.
3149 Env<AttrContext> env = enter.typeEnvs.get(c);
3150
3151 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
3152 // because the annotations were not available at the time the env was created. Therefore,
3153 // we look up the environment chain for the first enclosing environment for which the
3154 // lint value is set. Typically, this is the parent env, but might be further if there
3155 // are any envs created as a result of TypeParameter nodes.
3156 Env<AttrContext> lintEnv = env;
3157 while (lintEnv.info.lint == null)
3158 lintEnv = lintEnv.next;
3159
3160 // Having found the enclosing lint value, we can initialize the lint value for this class
3161 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
3162
3163 Lint prevLint = chk.setLint(env.info.lint);
3164 JavaFileObject prev = log.useSource(c.sourcefile);
3165
3166 try {
3167 // java.lang.Enum may not be subclassed by a non-enum
3168 if (st.tsym == syms.enumSym &&
3169 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
3170 log.error(env.tree.pos(), "enum.no.subclassing");
3171
3172 // Enums may not be extended by source-level classes
3173 if (st.tsym != null &&
3174 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
3175 ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
3176 !target.compilerBootstrap(c)) {
3177 log.error(env.tree.pos(), "enum.types.not.extensible");
3178 }
3179 attribClassBody(env, c);
3180
3181 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
3182 } finally {
3183 log.useSource(prev);
3184 chk.setLint(prevLint);
3185 }
3186
3187 }
3188 }
3189
3190 public void visitImport(JCImport tree) {
3191 // nothing to do
3192 }
3193
3194 /** Finish the attribution of a class. */
3195 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
3196 JCClassDecl tree = (JCClassDecl)env.tree;
3197 Assert.check(c == tree.sym);
3198
3199 // Validate annotations
3200 chk.validateAnnotations(tree.mods.annotations, c);
3201
3202 // Validate type parameters, supertype and interfaces.
3203 attribBounds(tree.typarams);
3204 if (!c.isAnonymous()) {
3205 //already checked if anonymous
3206 chk.validate(tree.typarams, env);
3207 chk.validate(tree.extending, env);
3208 chk.validate(tree.implementing, env);
3209 }
3210
3211 // If this is a non-abstract class, check that it has no abstract
3212 // methods or unimplemented methods of an implemented interface.
3213 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
3214 if (!relax)
3215 chk.checkAllDefined(tree.pos(), c);
3216 }
3217
3218 if ((c.flags() & ANNOTATION) != 0) {
3219 if (tree.implementing.nonEmpty())
3220 log.error(tree.implementing.head.pos(),
3221 "cant.extend.intf.annotation");
3222 if (tree.typarams.nonEmpty())
3223 log.error(tree.typarams.head.pos(),
3224 "intf.annotation.cant.have.type.params");
3225 } else {
3226 // Check that all extended classes and interfaces
3227 // are compatible (i.e. no two define methods with same arguments
3228 // yet different return types). (JLS 8.4.6.3)
3229 chk.checkCompatibleSupertypes(tree.pos(), c.type);
3230 }
3231
3232 // Check that class does not import the same parameterized interface
3233 // with two different argument lists.
3234 chk.checkClassBounds(tree.pos(), c.type);
3235
3236 tree.type = c.type;
3237
3238 for (List<JCTypeParameter> l = tree.typarams;
3239 l.nonEmpty(); l = l.tail) {
3240 Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope);
3241 }
3242
3243 // Check that a generic class doesn't extend Throwable
3244 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
3245 log.error(tree.extending.pos(), "generic.throwable");
3246
3247 // Check that all methods which implement some
3248 // method conform to the method they implement.
3249 chk.checkImplementations(tree);
3250
3251 //check that a resource implementing AutoCloseable cannot throw InterruptedException
3252 checkAutoCloseable(tree.pos(), env, c.type);
3253
3254 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3255 // Attribute declaration
3256 attribStat(l.head, env);
3257 // Check that declarations in inner classes are not static (JLS 8.1.2)
3258 // Make an exception for static constants.
3259 if (c.owner.kind != PCK &&
3260 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
3261 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
3262 Symbol sym = null;
3263 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
3264 if (sym == null ||
3265 sym.kind != VAR ||
3266 ((VarSymbol) sym).getConstValue() == null)
3267 log.error(l.head.pos(), "icls.cant.have.static.decl", c);
3268 }
3269 }
3270
3271 // Check for cycles among non-initial constructors.
3272 chk.checkCyclicConstructors(tree);
3273
3274 // Check for cycles among annotation elements.
3275 chk.checkNonCyclicElements(tree);
3276
3277 // Check for proper use of serialVersionUID
3278 if (env.info.lint.isEnabled(LintCategory.SERIAL) &&
3279 isSerializable(c) &&
3280 (c.flags() & Flags.ENUM) == 0 &&
3281 (c.flags() & ABSTRACT) == 0) {
3282 checkSerialVersionUID(tree, c);
3283 }
3284 }
3285 // where
3286 /** check if a class is a subtype of Serializable, if that is available. */
3287 private boolean isSerializable(ClassSymbol c) {
3288 try {
3289 syms.serializableType.complete();
3290 }
3291 catch (CompletionFailure e) {
3292 return false;
3293 }
3294 return types.isSubtype(c.type, syms.serializableType);
3295 }
3296
3297 /** Check that an appropriate serialVersionUID member is defined. */
3298 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
3299
3300 // check for presence of serialVersionUID
3301 Scope.Entry e = c.members().lookup(names.serialVersionUID);
3302 while (e.scope != null && e.sym.kind != VAR) e = e.next();
3303 if (e.scope == null) {
3304 log.warning(LintCategory.SERIAL,
3305 tree.pos(), "missing.SVUID", c);
3306 return;
3307 }
3308
3309 // check that it is static final
3310 VarSymbol svuid = (VarSymbol)e.sym;
3311 if ((svuid.flags() & (STATIC | FINAL)) !=
3312 (STATIC | FINAL))
3313 log.warning(LintCategory.SERIAL,
3314 TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
3315
3316 // check that it is long
3317 else if (svuid.type.tag != TypeTags.LONG)
3318 log.warning(LintCategory.SERIAL,
3319 TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
3320
3321 // check constant
3322 else if (svuid.getConstValue() == null)
3323 log.warning(LintCategory.SERIAL,
3324 TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
3325 }
3326
3327 private Type capture(Type type) {
3328 return types.capture(type);
3329 }
3330
3331 // <editor-fold desc="post-attribution visitor">
3332
3333 /**
3334 * Handle missing types/symbols in an AST. This routine is useful when
3335 * the compiler has encountered some errors (which might have ended up
3336 * terminating attribution abruptly); if the compiler is used in fail-over
3337 * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
3338 * prevents NPE to be progagated during subsequent compilation steps.
3339 */
3340 public void postAttr(Env<AttrContext> env) {
3341 new PostAttrAnalyzer().scan(env.tree);
3342 }
3343
3344 class PostAttrAnalyzer extends TreeScanner {
3345
3346 private void initTypeIfNeeded(JCTree that) {
3347 if (that.type == null) {
3348 that.type = syms.unknownType;
3349 }
3350 }
3351
3352 @Override
3353 public void scan(JCTree tree) {
3354 if (tree == null) return;
3355 if (tree instanceof JCExpression) {
3356 initTypeIfNeeded(tree);
3357 }
3358 super.scan(tree);
3359 }
3360
3361 @Override
3362 public void visitIdent(JCIdent that) {
3363 if (that.sym == null) {
3364 that.sym = syms.unknownSymbol;
3365 }
3366 }
3367
3368 @Override
3369 public void visitSelect(JCFieldAccess that) {
3370 if (that.sym == null) {
3371 that.sym = syms.unknownSymbol;
3372 }
3373 super.visitSelect(that);
3374 }
3375
3376 @Override
3377 public void visitClassDef(JCClassDecl that) {
3378 initTypeIfNeeded(that);
3379 if (that.sym == null) {
3380 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
3381 }
3382 super.visitClassDef(that);
3383 }
3384
3385 @Override
3386 public void visitMethodDef(JCMethodDecl that) {
3387 initTypeIfNeeded(that);
3388 if (that.sym == null) {
3389 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
3390 }
3391 super.visitMethodDef(that);
3392 }
3393
3394 @Override
3395 public void visitVarDef(JCVariableDecl that) {
3396 initTypeIfNeeded(that);
3397 if (that.sym == null) {
3398 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
3399 that.sym.adr = 0;
3400 }
3401 super.visitVarDef(that);
3402 }
3403
3404 @Override
3405 public void visitNewClass(JCNewClass that) {
3406 if (that.constructor == null) {
3407 that.constructor = new MethodSymbol(0, names.init, syms.unknownType, syms.noSymbol);
3408 }
3409 if (that.constructorType == null) {
3410 that.constructorType = syms.unknownType;
3411 }
3412 super.visitNewClass(that);
3413 }
3414
3415 @Override
3416 public void visitAssignop(JCAssignOp that) {
3417 if (that.operator == null)
3418 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3419 super.visitAssignop(that);
3420 }
3421
3422 @Override
3423 public void visitBinary(JCBinary that) {
3424 if (that.operator == null)
3425 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3426 super.visitBinary(that);
3427 }
3428
3429 @Override
3430 public void visitUnary(JCUnary that) {
3431 if (that.operator == null)
3432 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3433 super.visitUnary(that);
3434 }
3435 }
3436 // </editor-fold>
3437 }