1 /*
2 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.comp;
27
28 import java.util.*;
29 import java.util.Set;
30 import javax.lang.model.element.ElementKind;
31 import javax.tools.JavaFileObject;
32
33 import com.sun.tools.javac.code.*;
34 import com.sun.tools.javac.jvm.*;
35 import com.sun.tools.javac.tree.*;
36 import com.sun.tools.javac.util.*;
37 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
38 import com.sun.tools.javac.util.List;
39
40 import com.sun.tools.javac.jvm.Target;
41 import com.sun.tools.javac.code.Lint.LintCategory;
42 import com.sun.tools.javac.code.Symbol.*;
43 import com.sun.tools.javac.tree.JCTree.*;
44 import com.sun.tools.javac.code.Type.*;
45
46 import com.sun.source.tree.IdentifierTree;
47 import com.sun.source.tree.MemberSelectTree;
48 import com.sun.source.tree.TreeVisitor;
49 import com.sun.source.util.SimpleTreeVisitor;
50
51 import static com.sun.tools.javac.code.Flags.*;
52 import static com.sun.tools.javac.code.Kinds.*;
53 import static com.sun.tools.javac.code.TypeTags.*;
54
55 /** This is the main context-dependent analysis phase in GJC. It
56 * encompasses name resolution, type checking and constant folding as
57 * subtasks. Some subtasks involve auxiliary classes.
58 * @see Check
59 * @see Resolve
60 * @see ConstFold
61 * @see Infer
62 *
63 * <p><b>This is NOT part of any supported API.
64 * If you write code that depends on this, you do so at your own risk.
65 * This code and its internal interfaces are subject to change or
66 * deletion without notice.</b>
67 */
68 public class Attr extends JCTree.Visitor {
69 protected static final Context.Key<Attr> attrKey =
70 new Context.Key<Attr>();
71
72 final Names names;
73 final Log log;
74 final Symtab syms;
75 final Resolve rs;
76 final Infer infer;
77 final Check chk;
78 final MemberEnter memberEnter;
79 final TreeMaker make;
80 final ConstFold cfolder;
81 final Enter enter;
82 final Target target;
83 final Types types;
84 final JCDiagnostic.Factory diags;
85 final Annotate annotate;
86 final DeferredLintHandler deferredLintHandler;
87
88 public static Attr instance(Context context) {
89 Attr instance = context.get(attrKey);
90 if (instance == null)
91 instance = new Attr(context);
92 return instance;
93 }
94
95 protected Attr(Context context) {
96 context.put(attrKey, this);
97
98 names = Names.instance(context);
99 log = Log.instance(context);
100 syms = Symtab.instance(context);
101 rs = Resolve.instance(context);
102 chk = Check.instance(context);
103 memberEnter = MemberEnter.instance(context);
104 make = TreeMaker.instance(context);
105 enter = Enter.instance(context);
106 infer = Infer.instance(context);
107 cfolder = ConstFold.instance(context);
108 target = Target.instance(context);
109 types = Types.instance(context);
110 diags = JCDiagnostic.Factory.instance(context);
111 annotate = Annotate.instance(context);
112 deferredLintHandler = DeferredLintHandler.instance(context);
113
114 Options options = Options.instance(context);
115
116 Source source = Source.instance(context);
117 allowGenerics = source.allowGenerics();
118 allowVarargs = source.allowVarargs();
119 allowEnums = source.allowEnums();
120 allowBoxing = source.allowBoxing();
121 allowCovariantReturns = source.allowCovariantReturns();
122 allowAnonOuterThis = source.allowAnonOuterThis();
123 allowStringsInSwitch = source.allowStringsInSwitch();
124 sourceName = source.name;
125 relax = (options.isSet("-retrofit") ||
126 options.isSet("-relax"));
127 findDiamonds = options.get("findDiamond") != null &&
128 source.allowDiamond();
129 useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
130 }
131
132 /** Switch: relax some constraints for retrofit mode.
133 */
134 boolean relax;
135
136 /** Switch: support generics?
137 */
138 boolean allowGenerics;
139
140 /** Switch: allow variable-arity methods.
141 */
142 boolean allowVarargs;
143
144 /** Switch: support enums?
145 */
146 boolean allowEnums;
147
148 /** Switch: support boxing and unboxing?
149 */
150 boolean allowBoxing;
151
152 /** Switch: support covariant result types?
153 */
154 boolean allowCovariantReturns;
155
156 /** Switch: allow references to surrounding object from anonymous
157 * objects during constructor call?
158 */
159 boolean allowAnonOuterThis;
160
161 /** Switch: generates a warning if diamond can be safely applied
162 * to a given new expression
163 */
164 boolean findDiamonds;
165
166 /**
167 * Internally enables/disables diamond finder feature
168 */
169 static final boolean allowDiamondFinder = true;
170
171 /**
172 * Switch: warn about use of variable before declaration?
173 * RFE: 6425594
174 */
175 boolean useBeforeDeclarationWarning;
176
177 /**
178 * Switch: allow strings in switch?
179 */
180 boolean allowStringsInSwitch;
181
182 /**
183 * Switch: name of source level; used for error reporting.
184 */
185 String sourceName;
186
187 /** Check kind and type of given tree against protokind and prototype.
188 * If check succeeds, store type in tree and return it.
189 * If check fails, store errType in tree and return it.
190 * No checks are performed if the prototype is a method type.
191 * It is not necessary in this case since we know that kind and type
192 * are correct.
193 *
194 * @param tree The tree whose kind and type is checked
195 * @param owntype The computed type of the tree
196 * @param ownkind The computed kind of the tree
197 * @param pkind The expected kind (or: protokind) of the tree
198 * @param pt The expected type (or: prototype) of the tree
199 */
200 Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
201 if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
202 if ((ownkind & ~pkind) == 0) {
203 owntype = chk.checkType(tree.pos(), owntype, pt, errKey);
204 } else {
205 log.error(tree.pos(), "unexpected.type",
206 kindNames(pkind),
207 kindName(ownkind));
208 owntype = types.createErrorType(owntype);
209 }
210 }
211 tree.type = owntype;
212 return owntype;
213 }
214
215 /** Is given blank final variable assignable, i.e. in a scope where it
216 * may be assigned to even though it is final?
217 * @param v The blank final variable.
218 * @param env The current environment.
219 */
220 boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
221 Symbol owner = env.info.scope.owner;
222 // owner refers to the innermost variable, method or
223 // initializer block declaration at this point.
224 return
225 v.owner == owner
226 ||
227 ((owner.name == names.init || // i.e. we are in a constructor
228 owner.kind == VAR || // i.e. we are in a variable initializer
229 (owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
230 &&
231 v.owner == owner.owner
232 &&
233 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
234 }
235
236 /** Check that variable can be assigned to.
237 * @param pos The current source code position.
238 * @param v The assigned varaible
239 * @param base If the variable is referred to in a Select, the part
240 * to the left of the `.', null otherwise.
241 * @param env The current environment.
242 */
243 void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
244 if ((v.flags() & FINAL) != 0 &&
245 ((v.flags() & HASINIT) != 0
246 ||
247 !((base == null ||
248 (base.getTag() == JCTree.Tag.IDENT && TreeInfo.name(base) == names._this)) &&
249 isAssignableAsBlankFinal(v, env)))) {
250 if (v.isResourceVariable()) { //TWR resource
251 log.error(pos, "try.resource.may.not.be.assigned", v);
252 } else {
253 log.error(pos, "cant.assign.val.to.final.var", v);
254 }
255 } else if ((v.flags() & EFFECTIVELY_FINAL) != 0) {
256 v.flags_field &= ~EFFECTIVELY_FINAL;
257 }
258 }
259
260 /** Does tree represent a static reference to an identifier?
261 * It is assumed that tree is either a SELECT or an IDENT.
262 * We have to weed out selects from non-type names here.
263 * @param tree The candidate tree.
264 */
265 boolean isStaticReference(JCTree tree) {
266 if (tree.getTag() == JCTree.Tag.SELECT) {
267 Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
268 if (lsym == null || lsym.kind != TYP) {
269 return false;
270 }
271 }
272 return true;
273 }
274
275 /** Is this symbol a type?
276 */
277 static boolean isType(Symbol sym) {
278 return sym != null && sym.kind == TYP;
279 }
280
281 /** The current `this' symbol.
282 * @param env The current environment.
283 */
284 Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
285 return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
286 }
287
288 /** Attribute a parsed identifier.
289 * @param tree Parsed identifier name
290 * @param topLevel The toplevel to use
291 */
292 public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
293 Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
294 localEnv.enclClass = make.ClassDef(make.Modifiers(0),
295 syms.errSymbol.name,
296 null, null, null, null);
297 localEnv.enclClass.sym = syms.errSymbol;
298 return tree.accept(identAttributer, localEnv);
299 }
300 // where
301 private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
302 private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
303 @Override
304 public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
305 Symbol site = visit(node.getExpression(), env);
306 if (site.kind == ERR)
307 return site;
308 Name name = (Name)node.getIdentifier();
309 if (site.kind == PCK) {
310 env.toplevel.packge = (PackageSymbol)site;
311 return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
312 } else {
313 env.enclClass.sym = (ClassSymbol)site;
314 return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
315 }
316 }
317
318 @Override
319 public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
320 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
321 }
322 }
323
324 public Type coerce(Type etype, Type ttype) {
325 return cfolder.coerce(etype, ttype);
326 }
327
328 public Type attribType(JCTree node, TypeSymbol sym) {
329 Env<AttrContext> env = enter.typeEnvs.get(sym);
330 Env<AttrContext> localEnv = env.dup(node, env.info.dup());
331 return attribTree(node, localEnv, Kinds.TYP, Type.noType);
332 }
333
334 public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
335 breakTree = tree;
336 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
337 try {
338 attribExpr(expr, env);
339 } catch (BreakAttr b) {
340 return b.env;
341 } catch (AssertionError ae) {
342 if (ae.getCause() instanceof BreakAttr) {
343 return ((BreakAttr)(ae.getCause())).env;
344 } else {
345 throw ae;
346 }
347 } finally {
348 breakTree = null;
349 log.useSource(prev);
350 }
351 return env;
352 }
353
354 public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
355 breakTree = tree;
356 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
357 try {
358 attribStat(stmt, env);
359 } catch (BreakAttr b) {
360 return b.env;
361 } catch (AssertionError ae) {
362 if (ae.getCause() instanceof BreakAttr) {
363 return ((BreakAttr)(ae.getCause())).env;
364 } else {
365 throw ae;
366 }
367 } finally {
368 breakTree = null;
369 log.useSource(prev);
370 }
371 return env;
372 }
373
374 private JCTree breakTree = null;
375
376 private static class BreakAttr extends RuntimeException {
377 static final long serialVersionUID = -6924771130405446405L;
378 private Env<AttrContext> env;
379 private BreakAttr(Env<AttrContext> env) {
380 this.env = env;
381 }
382 }
383
384
385 /* ************************************************************************
386 * Visitor methods
387 *************************************************************************/
388
389 /** Visitor argument: the current environment.
390 */
391 Env<AttrContext> env;
392
393 /** Visitor argument: the currently expected proto-kind.
394 */
395 int pkind;
396
397 /** Visitor argument: the currently expected proto-type.
398 */
399 Type pt;
400
401 /** Visitor argument: the error key to be generated when a type error occurs
402 */
403 String errKey;
404
405 /** Visitor result: the computed type.
406 */
407 Type result;
408
409 /** Visitor method: attribute a tree, catching any completion failure
410 * exceptions. Return the tree's type.
411 *
412 * @param tree The tree to be visited.
413 * @param env The environment visitor argument.
414 * @param pkind The protokind visitor argument.
415 * @param pt The prototype visitor argument.
416 */
417 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) {
418 return attribTree(tree, env, pkind, pt, "incompatible.types");
419 }
420
421 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt, String errKey) {
422 Env<AttrContext> prevEnv = this.env;
423 int prevPkind = this.pkind;
424 Type prevPt = this.pt;
425 String prevErrKey = this.errKey;
426 try {
427 this.env = env;
428 this.pkind = pkind;
429 this.pt = pt;
430 this.errKey = errKey;
431 tree.accept(this);
432 if (tree == breakTree)
433 throw new BreakAttr(env);
434 return result;
435 } catch (CompletionFailure ex) {
436 tree.type = syms.errType;
437 return chk.completionError(tree.pos(), ex);
438 } finally {
439 this.env = prevEnv;
440 this.pkind = prevPkind;
441 this.pt = prevPt;
442 this.errKey = prevErrKey;
443 }
444 }
445
446 /** Derived visitor method: attribute an expression tree.
447 */
448 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
449 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
450 }
451
452 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt, String key) {
453 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType, key);
454 }
455
456 /** Derived visitor method: attribute an expression tree with
457 * no constraints on the computed type.
458 */
459 Type attribExpr(JCTree tree, Env<AttrContext> env) {
460 return attribTree(tree, env, VAL, Type.noType);
461 }
462
463 /** Derived visitor method: attribute a type tree.
464 */
465 Type attribType(JCTree tree, Env<AttrContext> env) {
466 Type result = attribType(tree, env, Type.noType);
467 return result;
468 }
469
470 /** Derived visitor method: attribute a type tree.
471 */
472 Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
473 Type result = attribTree(tree, env, TYP, pt);
474 return result;
475 }
476
477 /** Derived visitor method: attribute a statement or definition tree.
478 */
479 public Type attribStat(JCTree tree, Env<AttrContext> env) {
480 return attribTree(tree, env, NIL, Type.noType);
481 }
482
483 /** Attribute a list of expressions, returning a list of types.
484 */
485 List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
486 ListBuffer<Type> ts = new ListBuffer<Type>();
487 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
488 ts.append(attribExpr(l.head, env, pt));
489 return ts.toList();
490 }
491
492 /** Attribute a list of statements, returning nothing.
493 */
494 <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
495 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
496 attribStat(l.head, env);
497 }
498
499 /** Attribute the arguments in a method call, returning a list of types.
500 */
501 List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
502 ListBuffer<Type> argtypes = new ListBuffer<Type>();
503 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
504 argtypes.append(chk.checkNonVoid(
505 l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly))));
506 return argtypes.toList();
507 }
508
509 /** Attribute a type argument list, returning a list of types.
510 * Caller is responsible for calling checkRefTypes.
511 */
512 List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
513 ListBuffer<Type> argtypes = new ListBuffer<Type>();
514 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
515 argtypes.append(attribType(l.head, env));
516 return argtypes.toList();
517 }
518
519 /** Attribute a type argument list, returning a list of types.
520 * Check that all the types are references.
521 */
522 List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
523 List<Type> types = attribAnyTypes(trees, env);
524 return chk.checkRefTypes(trees, types);
525 }
526
527 /**
528 * Attribute type variables (of generic classes or methods).
529 * Compound types are attributed later in attribBounds.
530 * @param typarams the type variables to enter
531 * @param env the current environment
532 */
533 void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
534 for (JCTypeParameter tvar : typarams) {
535 TypeVar a = (TypeVar)tvar.type;
536 a.tsym.flags_field |= UNATTRIBUTED;
537 a.bound = Type.noType;
538 if (!tvar.bounds.isEmpty()) {
539 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
540 for (JCExpression bound : tvar.bounds.tail)
541 bounds = bounds.prepend(attribType(bound, env));
542 types.setBounds(a, bounds.reverse());
543 } else {
544 // if no bounds are given, assume a single bound of
545 // java.lang.Object.
546 types.setBounds(a, List.of(syms.objectType));
547 }
548 a.tsym.flags_field &= ~UNATTRIBUTED;
549 }
550 for (JCTypeParameter tvar : typarams)
551 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
552 attribStats(typarams, env);
553 }
554
555 void attribBounds(List<JCTypeParameter> typarams) {
556 for (JCTypeParameter typaram : typarams) {
557 Type bound = typaram.type.getUpperBound();
558 if (bound != null && bound.tsym instanceof ClassSymbol) {
559 ClassSymbol c = (ClassSymbol)bound.tsym;
560 if ((c.flags_field & COMPOUND) != 0) {
561 Assert.check((c.flags_field & UNATTRIBUTED) != 0, c);
562 attribClass(typaram.pos(), c);
563 }
564 }
565 }
566 }
567
568 /**
569 * Attribute the type references in a list of annotations.
570 */
571 void attribAnnotationTypes(List<JCAnnotation> annotations,
572 Env<AttrContext> env) {
573 for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
574 JCAnnotation a = al.head;
575 attribType(a.annotationType, env);
576 }
577 }
578
579 /**
580 * Attribute a "lazy constant value".
581 * @param env The env for the const value
582 * @param initializer The initializer for the const value
583 * @param type The expected type, or null
584 * @see VarSymbol#setlazyConstValue
585 */
586 public Object attribLazyConstantValue(Env<AttrContext> env,
587 JCTree.JCExpression initializer,
588 Type type) {
589
590 // in case no lint value has been set up for this env, scan up
591 // env stack looking for smallest enclosing env for which it is set.
592 Env<AttrContext> lintEnv = env;
593 while (lintEnv.info.lint == null)
594 lintEnv = lintEnv.next;
595
596 // Having found the enclosing lint value, we can initialize the lint value for this class
597 // ... but ...
598 // There's a problem with evaluating annotations in the right order, such that
599 // env.info.enclVar.attributes_field might not yet have been evaluated, and so might be
600 // null. In that case, calling augment will throw an NPE. To avoid this, for now we
601 // revert to the jdk 6 behavior and ignore the (unevaluated) attributes.
602 if (env.info.enclVar.attributes_field == null)
603 env.info.lint = lintEnv.info.lint;
604 else
605 env.info.lint = lintEnv.info.lint.augment(env.info.enclVar.attributes_field, env.info.enclVar.flags());
606
607 Lint prevLint = chk.setLint(env.info.lint);
608 JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
609
610 try {
611 Type itype = attribExpr(initializer, env, type);
612 if (itype.constValue() != null)
613 return coerce(itype, type).constValue();
614 else
615 return null;
616 } finally {
617 env.info.lint = prevLint;
618 log.useSource(prevSource);
619 }
620 }
621
622 /** Attribute type reference in an `extends' or `implements' clause.
623 * Supertypes of anonymous inner classes are usually already attributed.
624 *
625 * @param tree The tree making up the type reference.
626 * @param env The environment current at the reference.
627 * @param classExpected true if only a class is expected here.
628 * @param interfaceExpected true if only an interface is expected here.
629 */
630 Type attribBase(JCTree tree,
631 Env<AttrContext> env,
632 boolean classExpected,
633 boolean interfaceExpected,
634 boolean checkExtensible) {
635 Type t = tree.type != null ?
636 tree.type :
637 attribType(tree, env);
638 return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
639 }
640 Type checkBase(Type t,
641 JCTree tree,
642 Env<AttrContext> env,
643 boolean classExpected,
644 boolean interfaceExpected,
645 boolean checkExtensible) {
646 if (t.isErroneous())
647 return t;
648 if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
649 // check that type variable is already visible
650 if (t.getUpperBound() == null) {
651 log.error(tree.pos(), "illegal.forward.ref");
652 return types.createErrorType(t);
653 }
654 } else {
655 t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
656 }
657 if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
658 log.error(tree.pos(), "intf.expected.here");
659 // return errType is necessary since otherwise there might
660 // be undetected cycles which cause attribution to loop
661 return types.createErrorType(t);
662 } else if (checkExtensible &&
663 classExpected &&
664 (t.tsym.flags() & INTERFACE) != 0) {
665 log.error(tree.pos(), "no.intf.expected.here");
666 return types.createErrorType(t);
667 }
668 if (checkExtensible &&
669 ((t.tsym.flags() & FINAL) != 0)) {
670 log.error(tree.pos(),
671 "cant.inherit.from.final", t.tsym);
672 }
673 chk.checkNonCyclic(tree.pos(), t);
674 return t;
675 }
676
677 public void visitClassDef(JCClassDecl tree) {
678 // Local classes have not been entered yet, so we need to do it now:
679 if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
680 enter.classEnter(tree, env);
681
682 ClassSymbol c = tree.sym;
683 if (c == null) {
684 // exit in case something drastic went wrong during enter.
685 result = null;
686 } else {
687 // make sure class has been completed:
688 c.complete();
689
690 // If this class appears as an anonymous class
691 // in a superclass constructor call where
692 // no explicit outer instance is given,
693 // disable implicit outer instance from being passed.
694 // (This would be an illegal access to "this before super").
695 if (env.info.isSelfCall &&
696 env.tree.getTag() == JCTree.Tag.NEWCLASS &&
697 ((JCNewClass) env.tree).encl == null)
698 {
699 c.flags_field |= NOOUTERTHIS;
700 }
701 attribClass(tree.pos(), c);
702 result = tree.type = c.type;
703 }
704 }
705
706 public void visitMethodDef(JCMethodDecl tree) {
707 MethodSymbol m = tree.sym;
708
709 Lint lint = env.info.lint.augment(m.attributes_field, m.flags());
710 Lint prevLint = chk.setLint(lint);
711 MethodSymbol prevMethod = chk.setMethod(m);
712 try {
713 deferredLintHandler.flush(tree.pos());
714 chk.checkDeprecatedAnnotation(tree.pos(), m);
715
716 attribBounds(tree.typarams);
717
718 // If we override any other methods, check that we do so properly.
719 // JLS ???
720 if (m.isStatic()) {
721 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
722 } else {
723 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
724 }
725 chk.checkOverride(tree, m);
726
727 // Create a new environment with local scope
728 // for attributing the method.
729 Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
730
731 localEnv.info.lint = lint;
732
733 // Enter all type parameters into the local method scope.
734 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
735 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
736
737 ClassSymbol owner = env.enclClass.sym;
738 if ((owner.flags() & ANNOTATION) != 0 &&
739 tree.params.nonEmpty())
740 log.error(tree.params.head.pos(),
741 "intf.annotation.members.cant.have.params");
742
743 // Attribute all value parameters.
744 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
745 attribStat(l.head, localEnv);
746 }
747
748 chk.checkVarargsMethodDecl(localEnv, tree);
749
750 // Check that type parameters are well-formed.
751 chk.validate(tree.typarams, localEnv);
752
753 // Check that result type is well-formed.
754 chk.validate(tree.restype, localEnv);
755
756 // annotation method checks
757 if ((owner.flags() & ANNOTATION) != 0) {
758 // annotation method cannot have throws clause
759 if (tree.thrown.nonEmpty()) {
760 log.error(tree.thrown.head.pos(),
761 "throws.not.allowed.in.intf.annotation");
762 }
763 // annotation method cannot declare type-parameters
764 if (tree.typarams.nonEmpty()) {
765 log.error(tree.typarams.head.pos(),
766 "intf.annotation.members.cant.have.type.params");
767 }
768 // validate annotation method's return type (could be an annotation type)
769 chk.validateAnnotationType(tree.restype);
770 // ensure that annotation method does not clash with members of Object/Annotation
771 chk.validateAnnotationMethod(tree.pos(), m);
772
773 if (tree.defaultValue != null) {
774 // if default value is an annotation, check it is a well-formed
775 // annotation value (e.g. no duplicate values, no missing values, etc.)
776 chk.validateAnnotationTree(tree.defaultValue);
777 }
778 }
779
780 for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
781 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
782
783 if (tree.body == null) {
784 // Empty bodies are only allowed for
785 // abstract, native, or interface methods, or for methods
786 // in a retrofit signature class.
787 if ((owner.flags() & INTERFACE) == 0 &&
788 (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 &&
789 !relax)
790 log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
791 if (tree.defaultValue != null) {
792 if ((owner.flags() & ANNOTATION) == 0)
793 log.error(tree.pos(),
794 "default.allowed.in.intf.annotation.member");
795 }
796 } else if ((owner.flags() & INTERFACE) != 0) {
797 log.error(tree.body.pos(), "intf.meth.cant.have.body");
798 } else if ((tree.mods.flags & ABSTRACT) != 0) {
799 log.error(tree.pos(), "abstract.meth.cant.have.body");
800 } else if ((tree.mods.flags & NATIVE) != 0) {
801 log.error(tree.pos(), "native.meth.cant.have.body");
802 } else {
803 // Add an implicit super() call unless an explicit call to
804 // super(...) or this(...) is given
805 // or we are compiling class java.lang.Object.
806 if (tree.name == names.init && owner.type != syms.objectType) {
807 JCBlock body = tree.body;
808 if (body.stats.isEmpty() ||
809 !TreeInfo.isSelfCall(body.stats.head)) {
810 body.stats = body.stats.
811 prepend(memberEnter.SuperCall(make.at(body.pos),
812 List.<Type>nil(),
813 List.<JCVariableDecl>nil(),
814 false));
815 } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
816 (tree.mods.flags & GENERATEDCONSTR) == 0 &&
817 TreeInfo.isSuperCall(body.stats.head)) {
818 // enum constructors are not allowed to call super
819 // directly, so make sure there aren't any super calls
820 // in enum constructors, except in the compiler
821 // generated one.
822 log.error(tree.body.stats.head.pos(),
823 "call.to.super.not.allowed.in.enum.ctor",
824 env.enclClass.sym);
825 }
826 }
827
828 // Attribute method body.
829 attribStat(tree.body, localEnv);
830 }
831 localEnv.info.scope.leave();
832 result = tree.type = m.type;
833 chk.validateAnnotations(tree.mods.annotations, m);
834 }
835 finally {
836 chk.setLint(prevLint);
837 chk.setMethod(prevMethod);
838 }
839 }
840
841 public void visitVarDef(JCVariableDecl tree) {
842 // Local variables have not been entered yet, so we need to do it now:
843 if (env.info.scope.owner.kind == MTH) {
844 if (tree.sym != null) {
845 // parameters have already been entered
846 env.info.scope.enter(tree.sym);
847 } else {
848 memberEnter.memberEnter(tree, env);
849 annotate.flush();
850 }
851 tree.sym.flags_field |= EFFECTIVELY_FINAL;
852 }
853
854 VarSymbol v = tree.sym;
855 Lint lint = env.info.lint.augment(v.attributes_field, v.flags());
856 Lint prevLint = chk.setLint(lint);
857
858 // Check that the variable's declared type is well-formed.
859 chk.validate(tree.vartype, env);
860 deferredLintHandler.flush(tree.pos());
861
862 try {
863 chk.checkDeprecatedAnnotation(tree.pos(), v);
864
865 if (tree.init != null) {
866 if ((v.flags_field & FINAL) != 0 && tree.init.getTag() != JCTree.Tag.NEWCLASS) {
867 // In this case, `v' is final. Ensure that it's initializer is
868 // evaluated.
869 v.getConstValue(); // ensure initializer is evaluated
870 } else {
871 // Attribute initializer in a new environment
872 // with the declared variable as owner.
873 // Check that initializer conforms to variable's declared type.
874 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
875 initEnv.info.lint = lint;
876 // In order to catch self-references, we set the variable's
877 // declaration position to maximal possible value, effectively
878 // marking the variable as undefined.
879 initEnv.info.enclVar = v;
880 attribExpr(tree.init, initEnv, v.type);
881 }
882 }
883 result = tree.type = v.type;
884 chk.validateAnnotations(tree.mods.annotations, v);
885 }
886 finally {
887 chk.setLint(prevLint);
888 }
889 }
890
891 public void visitSkip(JCSkip tree) {
892 result = null;
893 }
894
895 public void visitBlock(JCBlock tree) {
896 if (env.info.scope.owner.kind == TYP) {
897 // Block is a static or instance initializer;
898 // let the owner of the environment be a freshly
899 // created BLOCK-method.
900 Env<AttrContext> localEnv =
901 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
902 localEnv.info.scope.owner =
903 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
904 env.info.scope.owner);
905 if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
906 attribStats(tree.stats, localEnv);
907 } else {
908 // Create a new local environment with a local scope.
909 Env<AttrContext> localEnv =
910 env.dup(tree, env.info.dup(env.info.scope.dup()));
911 attribStats(tree.stats, localEnv);
912 localEnv.info.scope.leave();
913 }
914 result = null;
915 }
916
917 public void visitDoLoop(JCDoWhileLoop tree) {
918 attribStat(tree.body, env.dup(tree));
919 attribExpr(tree.cond, env, syms.booleanType);
920 result = null;
921 }
922
923 public void visitWhileLoop(JCWhileLoop tree) {
924 attribExpr(tree.cond, env, syms.booleanType);
925 attribStat(tree.body, env.dup(tree));
926 result = null;
927 }
928
929 public void visitForLoop(JCForLoop tree) {
930 Env<AttrContext> loopEnv =
931 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
932 attribStats(tree.init, loopEnv);
933 if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
934 loopEnv.tree = tree; // before, we were not in loop!
935 attribStats(tree.step, loopEnv);
936 attribStat(tree.body, loopEnv);
937 loopEnv.info.scope.leave();
938 result = null;
939 }
940
941 public void visitForeachLoop(JCEnhancedForLoop tree) {
942 Env<AttrContext> loopEnv =
943 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
944 attribStat(tree.var, loopEnv);
945 Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
946 chk.checkNonVoid(tree.pos(), exprType);
947 Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
948 if (elemtype == null) {
949 // or perhaps expr implements Iterable<T>?
950 Type base = types.asSuper(exprType, syms.iterableType.tsym);
951 if (base == null) {
952 log.error(tree.expr.pos(),
953 "foreach.not.applicable.to.type",
954 exprType,
955 diags.fragment("type.req.array.or.iterable"));
956 elemtype = types.createErrorType(exprType);
957 } else {
958 List<Type> iterableParams = base.allparams();
959 elemtype = iterableParams.isEmpty()
960 ? syms.objectType
961 : types.upperBound(iterableParams.head);
962 }
963 }
964 chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
965 loopEnv.tree = tree; // before, we were not in loop!
966 attribStat(tree.body, loopEnv);
967 loopEnv.info.scope.leave();
968 result = null;
969 }
970
971 public void visitLabelled(JCLabeledStatement tree) {
972 // Check that label is not used in an enclosing statement
973 Env<AttrContext> env1 = env;
974 while (env1 != null && env1.tree.getTag() != JCTree.Tag.CLASSDEF) {
975 if (env1.tree.getTag() == JCTree.Tag.LABELLED &&
976 ((JCLabeledStatement) env1.tree).label == tree.label) {
977 log.error(tree.pos(), "label.already.in.use",
978 tree.label);
979 break;
980 }
981 env1 = env1.next;
982 }
983
984 attribStat(tree.body, env.dup(tree));
985 result = null;
986 }
987
988 public void visitSwitch(JCSwitch tree) {
989 Type seltype = attribExpr(tree.selector, env);
990
991 Env<AttrContext> switchEnv =
992 env.dup(tree, env.info.dup(env.info.scope.dup()));
993
994 boolean enumSwitch =
995 allowEnums &&
996 (seltype.tsym.flags() & Flags.ENUM) != 0;
997 boolean stringSwitch = false;
998 if (types.isSameType(seltype, syms.stringType)) {
999 if (allowStringsInSwitch) {
1000 stringSwitch = true;
1001 } else {
1002 log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName);
1003 }
1004 }
1005 if (!enumSwitch && !stringSwitch)
1006 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
1007
1008 // Attribute all cases and
1009 // check that there are no duplicate case labels or default clauses.
1010 Set<Object> labels = new HashSet<Object>(); // The set of case labels.
1011 boolean hasDefault = false; // Is there a default label?
1012 for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
1013 JCCase c = l.head;
1014 Env<AttrContext> caseEnv =
1015 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
1016 if (c.pat != null) {
1017 if (enumSwitch) {
1018 Symbol sym = enumConstant(c.pat, seltype);
1019 if (sym == null) {
1020 log.error(c.pat.pos(), "enum.label.must.be.unqualified.enum");
1021 } else if (!labels.add(sym)) {
1022 log.error(c.pos(), "duplicate.case.label");
1023 }
1024 } else {
1025 Type pattype = attribExpr(c.pat, switchEnv, seltype);
1026 if (pattype.tag != ERROR) {
1027 if (pattype.constValue() == null) {
1028 log.error(c.pat.pos(),
1029 (stringSwitch ? "string.const.req" : "const.expr.req"));
1030 } else if (labels.contains(pattype.constValue())) {
1031 log.error(c.pos(), "duplicate.case.label");
1032 } else {
1033 labels.add(pattype.constValue());
1034 }
1035 }
1036 }
1037 } else if (hasDefault) {
1038 log.error(c.pos(), "duplicate.default.label");
1039 } else {
1040 hasDefault = true;
1041 }
1042 attribStats(c.stats, caseEnv);
1043 caseEnv.info.scope.leave();
1044 addVars(c.stats, switchEnv.info.scope);
1045 }
1046
1047 switchEnv.info.scope.leave();
1048 result = null;
1049 }
1050 // where
1051 /** Add any variables defined in stats to the switch scope. */
1052 private static void addVars(List<JCStatement> stats, Scope switchScope) {
1053 for (;stats.nonEmpty(); stats = stats.tail) {
1054 JCTree stat = stats.head;
1055 if (stat.getTag() == JCTree.Tag.VARDEF)
1056 switchScope.enter(((JCVariableDecl) stat).sym);
1057 }
1058 }
1059 // where
1060 /** Return the selected enumeration constant symbol, or null. */
1061 private Symbol enumConstant(JCTree tree, Type enumType) {
1062 if (tree.getTag() != JCTree.Tag.IDENT) {
1063 log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
1064 return syms.errSymbol;
1065 }
1066 JCIdent ident = (JCIdent)tree;
1067 Name name = ident.name;
1068 for (Scope.Entry e = enumType.tsym.members().lookup(name);
1069 e.scope != null; e = e.next()) {
1070 if (e.sym.kind == VAR) {
1071 Symbol s = ident.sym = e.sym;
1072 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1073 ident.type = s.type;
1074 return ((s.flags_field & Flags.ENUM) == 0)
1075 ? null : s;
1076 }
1077 }
1078 return null;
1079 }
1080
1081 public void visitSynchronized(JCSynchronized tree) {
1082 chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
1083 attribStat(tree.body, env);
1084 result = null;
1085 }
1086
1087 public void visitTry(JCTry tree) {
1088 // Create a new local environment with a local
1089 Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1090 boolean isTryWithResource = tree.resources.nonEmpty();
1091 // Create a nested environment for attributing the try block if needed
1092 Env<AttrContext> tryEnv = isTryWithResource ?
1093 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1094 localEnv;
1095 // Attribute resource declarations
1096 for (JCTree resource : tree.resources) {
1097 if (resource.getTag() == JCTree.Tag.VARDEF) {
1098 attribStat(resource, tryEnv);
1099 chk.checkType(resource, resource.type, syms.autoCloseableType, "try.not.applicable.to.type");
1100
1101 //check that resource type cannot throw InterruptedException
1102 checkAutoCloseable(resource.pos(), localEnv, resource.type);
1103
1104 VarSymbol var = (VarSymbol)TreeInfo.symbolFor(resource);
1105 var.setData(ElementKind.RESOURCE_VARIABLE);
1106 } else {
1107 attribExpr(resource, tryEnv, syms.autoCloseableType, "try.not.applicable.to.type");
1108 }
1109 }
1110 // Attribute body
1111 attribStat(tree.body, tryEnv);
1112 if (isTryWithResource)
1113 tryEnv.info.scope.leave();
1114
1115 // Attribute catch clauses
1116 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
1117 JCCatch c = l.head;
1118 Env<AttrContext> catchEnv =
1119 localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
1120 Type ctype = attribStat(c.param, catchEnv);
1121 if (TreeInfo.isMultiCatch(c)) {
1122 //multi-catch parameter is implicitly marked as final
1123 c.param.sym.flags_field |= FINAL | UNION;
1124 }
1125 if (c.param.sym.kind == Kinds.VAR) {
1126 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
1127 }
1128 chk.checkType(c.param.vartype.pos(),
1129 chk.checkClassType(c.param.vartype.pos(), ctype),
1130 syms.throwableType);
1131 attribStat(c.body, catchEnv);
1132 catchEnv.info.scope.leave();
1133 }
1134
1135 // Attribute finalizer
1136 if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
1137
1138 localEnv.info.scope.leave();
1139 result = null;
1140 }
1141
1142 void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
1143 if (!resource.isErroneous() &&
1144 types.asSuper(resource, syms.autoCloseableType.tsym) != null) {
1145 Symbol close = syms.noSymbol;
1146 boolean prevDeferDiags = log.deferDiagnostics;
1147 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
1148 try {
1149 log.deferDiagnostics = true;
1150 log.deferredDiagnostics = ListBuffer.lb();
1151 close = rs.resolveQualifiedMethod(pos,
1152 env,
1153 resource,
1154 names.close,
1155 List.<Type>nil(),
1156 List.<Type>nil());
1157 }
1158 finally {
1159 log.deferDiagnostics = prevDeferDiags;
1160 log.deferredDiagnostics = prevDeferredDiags;
1161 }
1162 if (close.kind == MTH &&
1163 close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
1164 chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
1165 env.info.lint.isEnabled(LintCategory.TRY)) {
1166 log.warning(LintCategory.TRY, pos, "try.resource.throws.interrupted.exc", resource);
1167 }
1168 }
1169 }
1170
1171 public void visitConditional(JCConditional tree) {
1172 attribExpr(tree.cond, env, syms.booleanType);
1173 attribExpr(tree.truepart, env);
1174 attribExpr(tree.falsepart, env);
1175 result = check(tree,
1176 capture(condType(tree.pos(), tree.cond.type,
1177 tree.truepart.type, tree.falsepart.type)),
1178 VAL, pkind, pt);
1179 }
1180 //where
1181 /** Compute the type of a conditional expression, after
1182 * checking that it exists. See Spec 15.25.
1183 *
1184 * @param pos The source position to be used for
1185 * error diagnostics.
1186 * @param condtype The type of the expression's condition.
1187 * @param thentype The type of the expression's then-part.
1188 * @param elsetype The type of the expression's else-part.
1189 */
1190 private Type condType(DiagnosticPosition pos,
1191 Type condtype,
1192 Type thentype,
1193 Type elsetype) {
1194 Type ctype = condType1(pos, condtype, thentype, elsetype);
1195
1196 // If condition and both arms are numeric constants,
1197 // evaluate at compile-time.
1198 return ((condtype.constValue() != null) &&
1199 (thentype.constValue() != null) &&
1200 (elsetype.constValue() != null))
1201 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
1202 : ctype;
1203 }
1204 /** Compute the type of a conditional expression, after
1205 * checking that it exists. Does not take into
1206 * account the special case where condition and both arms
1207 * are constants.
1208 *
1209 * @param pos The source position to be used for error
1210 * diagnostics.
1211 * @param condtype The type of the expression's condition.
1212 * @param thentype The type of the expression's then-part.
1213 * @param elsetype The type of the expression's else-part.
1214 */
1215 private Type condType1(DiagnosticPosition pos, Type condtype,
1216 Type thentype, Type elsetype) {
1217 // If same type, that is the result
1218 if (types.isSameType(thentype, elsetype))
1219 return thentype.baseType();
1220
1221 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1222 ? thentype : types.unboxedType(thentype);
1223 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1224 ? elsetype : types.unboxedType(elsetype);
1225
1226 // Otherwise, if both arms can be converted to a numeric
1227 // type, return the least numeric type that fits both arms
1228 // (i.e. return larger of the two, or return int if one
1229 // arm is short, the other is char).
1230 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1231 // If one arm has an integer subrange type (i.e., byte,
1232 // short, or char), and the other is an integer constant
1233 // that fits into the subrange, return the subrange type.
1234 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1235 types.isAssignable(elseUnboxed, thenUnboxed))
1236 return thenUnboxed.baseType();
1237 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1238 types.isAssignable(thenUnboxed, elseUnboxed))
1239 return elseUnboxed.baseType();
1240
1241 for (int i = BYTE; i < VOID; i++) {
1242 Type candidate = syms.typeOfTag[i];
1243 if (types.isSubtype(thenUnboxed, candidate) &&
1244 types.isSubtype(elseUnboxed, candidate))
1245 return candidate;
1246 }
1247 }
1248
1249 // Those were all the cases that could result in a primitive
1250 if (allowBoxing) {
1251 if (thentype.isPrimitive())
1252 thentype = types.boxedClass(thentype).type;
1253 if (elsetype.isPrimitive())
1254 elsetype = types.boxedClass(elsetype).type;
1255 }
1256
1257 if (types.isSubtype(thentype, elsetype))
1258 return elsetype.baseType();
1259 if (types.isSubtype(elsetype, thentype))
1260 return thentype.baseType();
1261
1262 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1263 log.error(pos, "neither.conditional.subtype",
1264 thentype, elsetype);
1265 return thentype.baseType();
1266 }
1267
1268 // both are known to be reference types. The result is
1269 // lub(thentype,elsetype). This cannot fail, as it will
1270 // always be possible to infer "Object" if nothing better.
1271 return types.lub(thentype.baseType(), elsetype.baseType());
1272 }
1273
1274 public void visitIf(JCIf tree) {
1275 attribExpr(tree.cond, env, syms.booleanType);
1276 attribStat(tree.thenpart, env);
1277 if (tree.elsepart != null)
1278 attribStat(tree.elsepart, env);
1279 chk.checkEmptyIf(tree);
1280 result = null;
1281 }
1282
1283 public void visitExec(JCExpressionStatement tree) {
1284 //a fresh environment is required for 292 inference to work properly ---
1285 //see Infer.instantiatePolymorphicSignatureInstance()
1286 Env<AttrContext> localEnv = env.dup(tree);
1287 attribExpr(tree.expr, localEnv);
1288 result = null;
1289 }
1290
1291 public void visitBreak(JCBreak tree) {
1292 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1293 result = null;
1294 }
1295
1296 public void visitContinue(JCContinue tree) {
1297 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1298 result = null;
1299 }
1300 //where
1301 /** Return the target of a break or continue statement, if it exists,
1302 * report an error if not.
1303 * Note: The target of a labelled break or continue is the
1304 * (non-labelled) statement tree referred to by the label,
1305 * not the tree representing the labelled statement itself.
1306 *
1307 * @param pos The position to be used for error diagnostics
1308 * @param tag The tag of the jump statement. This is either
1309 * Tree.BREAK or Tree.CONTINUE.
1310 * @param label The label of the jump statement, or null if no
1311 * label is given.
1312 * @param env The environment current at the jump statement.
1313 */
1314 private JCTree findJumpTarget(DiagnosticPosition pos,
1315 JCTree.Tag tag,
1316 Name label,
1317 Env<AttrContext> env) {
1318 // Search environments outwards from the point of jump.
1319 Env<AttrContext> env1 = env;
1320 LOOP:
1321 while (env1 != null) {
1322 switch (env1.tree.getTag()) {
1323 case LABELLED:
1324 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1325 if (label == labelled.label) {
1326 // If jump is a continue, check that target is a loop.
1327 if (tag == JCTree.Tag.CONTINUE) {
1328 if (labelled.body.getTag() != JCTree.Tag.DOLOOP &&
1329 labelled.body.getTag() != JCTree.Tag.WHILELOOP &&
1330 labelled.body.getTag() != JCTree.Tag.FORLOOP &&
1331 labelled.body.getTag() != JCTree.Tag.FOREACHLOOP)
1332 log.error(pos, "not.loop.label", label);
1333 // Found labelled statement target, now go inwards
1334 // to next non-labelled tree.
1335 return TreeInfo.referencedStatement(labelled);
1336 } else {
1337 return labelled;
1338 }
1339 }
1340 break;
1341 case DOLOOP:
1342 case WHILELOOP:
1343 case FORLOOP:
1344 case FOREACHLOOP:
1345 if (label == null) return env1.tree;
1346 break;
1347 case SWITCH:
1348 if (label == null && tag == JCTree.Tag.BREAK) return env1.tree;
1349 break;
1350 case METHODDEF:
1351 case CLASSDEF:
1352 break LOOP;
1353 default:
1354 }
1355 env1 = env1.next;
1356 }
1357 if (label != null)
1358 log.error(pos, "undef.label", label);
1359 else if (tag == JCTree.Tag.CONTINUE)
1360 log.error(pos, "cont.outside.loop");
1361 else
1362 log.error(pos, "break.outside.switch.loop");
1363 return null;
1364 }
1365
1366 public void visitReturn(JCReturn tree) {
1367 // Check that there is an enclosing method which is
1368 // nested within than the enclosing class.
1369 if (env.enclMethod == null ||
1370 env.enclMethod.sym.owner != env.enclClass.sym) {
1371 log.error(tree.pos(), "ret.outside.meth");
1372
1373 } else {
1374 // Attribute return expression, if it exists, and check that
1375 // it conforms to result type of enclosing method.
1376 Symbol m = env.enclMethod.sym;
1377 if (m.type.getReturnType().tag == VOID) {
1378 if (tree.expr != null)
1379 log.error(tree.expr.pos(),
1380 "cant.ret.val.from.meth.decl.void");
1381 } else if (tree.expr == null) {
1382 log.error(tree.pos(), "missing.ret.val");
1383 } else {
1384 attribExpr(tree.expr, env, m.type.getReturnType());
1385 }
1386 }
1387 result = null;
1388 }
1389
1390 public void visitThrow(JCThrow tree) {
1391 attribExpr(tree.expr, env, syms.throwableType);
1392 result = null;
1393 }
1394
1395 public void visitAssert(JCAssert tree) {
1396 attribExpr(tree.cond, env, syms.booleanType);
1397 if (tree.detail != null) {
1398 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1399 }
1400 result = null;
1401 }
1402
1403 /** Visitor method for method invocations.
1404 * NOTE: The method part of an application will have in its type field
1405 * the return type of the method, not the method's type itself!
1406 */
1407 public void visitApply(JCMethodInvocation tree) {
1408 // The local environment of a method application is
1409 // a new environment nested in the current one.
1410 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1411
1412 // The types of the actual method arguments.
1413 List<Type> argtypes;
1414
1415 // The types of the actual method type arguments.
1416 List<Type> typeargtypes = null;
1417
1418 Name methName = TreeInfo.name(tree.meth);
1419
1420 boolean isConstructorCall =
1421 methName == names._this || methName == names._super;
1422
1423 if (isConstructorCall) {
1424 // We are seeing a ...this(...) or ...super(...) call.
1425 // Check that this is the first statement in a constructor.
1426 if (checkFirstConstructorStat(tree, env)) {
1427
1428 // Record the fact
1429 // that this is a constructor call (using isSelfCall).
1430 localEnv.info.isSelfCall = true;
1431
1432 // Attribute arguments, yielding list of argument types.
1433 argtypes = attribArgs(tree.args, localEnv);
1434 typeargtypes = attribTypes(tree.typeargs, localEnv);
1435
1436 // Variable `site' points to the class in which the called
1437 // constructor is defined.
1438 Type site = env.enclClass.sym.type;
1439 if (methName == names._super) {
1440 if (site == syms.objectType) {
1441 log.error(tree.meth.pos(), "no.superclass", site);
1442 site = types.createErrorType(syms.objectType);
1443 } else {
1444 site = types.supertype(site);
1445 }
1446 }
1447
1448 if (site.tag == CLASS) {
1449 Type encl = site.getEnclosingType();
1450 while (encl != null && encl.tag == TYPEVAR)
1451 encl = encl.getUpperBound();
1452 if (encl.tag == CLASS) {
1453 // we are calling a nested class
1454
1455 if (tree.meth.getTag() == JCTree.Tag.SELECT) {
1456 JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1457
1458 // We are seeing a prefixed call, of the form
1459 // <expr>.super(...).
1460 // Check that the prefix expression conforms
1461 // to the outer instance type of the class.
1462 chk.checkRefType(qualifier.pos(),
1463 attribExpr(qualifier, localEnv,
1464 encl));
1465 } else if (methName == names._super) {
1466 // qualifier omitted; check for existence
1467 // of an appropriate implicit qualifier.
1468 rs.resolveImplicitThis(tree.meth.pos(),
1469 localEnv, site, true);
1470 }
1471 } else if (tree.meth.getTag() == JCTree.Tag.SELECT) {
1472 log.error(tree.meth.pos(), "illegal.qual.not.icls",
1473 site.tsym);
1474 }
1475
1476 // if we're calling a java.lang.Enum constructor,
1477 // prefix the implicit String and int parameters
1478 if (site.tsym == syms.enumSym && allowEnums)
1479 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1480
1481 // Resolve the called constructor under the assumption
1482 // that we are referring to a superclass instance of the
1483 // current instance (JLS ???).
1484 boolean selectSuperPrev = localEnv.info.selectSuper;
1485 localEnv.info.selectSuper = true;
1486 localEnv.info.varArgs = false;
1487 Symbol sym = rs.resolveConstructor(
1488 tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1489 localEnv.info.selectSuper = selectSuperPrev;
1490
1491 // Set method symbol to resolved constructor...
1492 TreeInfo.setSymbol(tree.meth, sym);
1493
1494 // ...and check that it is legal in the current context.
1495 // (this will also set the tree's type)
1496 Type mpt = newMethTemplate(argtypes, typeargtypes);
1497 checkId(tree.meth, site, sym, localEnv, MTH,
1498 mpt, tree.varargsElement != null);
1499 }
1500 // Otherwise, `site' is an error type and we do nothing
1501 }
1502 result = tree.type = syms.voidType;
1503 } else {
1504 // Otherwise, we are seeing a regular method call.
1505 // Attribute the arguments, yielding list of argument types, ...
1506 argtypes = attribArgs(tree.args, localEnv);
1507 typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
1508
1509 // ... and attribute the method using as a prototype a methodtype
1510 // whose formal argument types is exactly the list of actual
1511 // arguments (this will also set the method symbol).
1512 Type mpt = newMethTemplate(argtypes, typeargtypes);
1513 localEnv.info.varArgs = false;
1514 Type mtype = attribExpr(tree.meth, localEnv, mpt);
1515 if (localEnv.info.varArgs)
1516 Assert.check(mtype.isErroneous() || tree.varargsElement != null);
1517
1518 // Compute the result type.
1519 Type restype = mtype.getReturnType();
1520 if (restype.tag == WILDCARD)
1521 throw new AssertionError(mtype);
1522
1523 // as a special case, array.clone() has a result that is
1524 // the same as static type of the array being cloned
1525 if (tree.meth.getTag() == JCTree.Tag.SELECT &&
1526 allowCovariantReturns &&
1527 methName == names.clone &&
1528 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1529 restype = ((JCFieldAccess) tree.meth).selected.type;
1530
1531 // as a special case, x.getClass() has type Class<? extends |X|>
1532 if (allowGenerics &&
1533 methName == names.getClass && tree.args.isEmpty()) {
1534 Type qualifier = (tree.meth.getTag() == JCTree.Tag.SELECT)
1535 ? ((JCFieldAccess) tree.meth).selected.type
1536 : env.enclClass.sym.type;
1537 restype = new
1538 ClassType(restype.getEnclosingType(),
1539 List.<Type>of(new WildcardType(types.erasure(qualifier),
1540 BoundKind.EXTENDS,
1541 syms.boundClass)),
1542 restype.tsym);
1543 }
1544
1545 chk.checkRefTypes(tree.typeargs, typeargtypes);
1546
1547 // Check that value of resulting type is admissible in the
1548 // current context. Also, capture the return type
1549 result = check(tree, capture(restype), VAL, pkind, pt);
1550 }
1551 chk.validate(tree.typeargs, localEnv);
1552 }
1553 //where
1554 /** Check that given application node appears as first statement
1555 * in a constructor call.
1556 * @param tree The application node
1557 * @param env The environment current at the application.
1558 */
1559 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1560 JCMethodDecl enclMethod = env.enclMethod;
1561 if (enclMethod != null && enclMethod.name == names.init) {
1562 JCBlock body = enclMethod.body;
1563 if (body.stats.head.getTag() == JCTree.Tag.EXEC &&
1564 ((JCExpressionStatement) body.stats.head).expr == tree)
1565 return true;
1566 }
1567 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1568 TreeInfo.name(tree.meth));
1569 return false;
1570 }
1571
1572 /** Obtain a method type with given argument types.
1573 */
1574 Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
1575 MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
1576 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1577 }
1578
1579 public void visitNewClass(JCNewClass tree) {
1580 Type owntype = types.createErrorType(tree.type);
1581
1582 // The local environment of a class creation is
1583 // a new environment nested in the current one.
1584 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1585
1586 // The anonymous inner class definition of the new expression,
1587 // if one is defined by it.
1588 JCClassDecl cdef = tree.def;
1589
1590 // If enclosing class is given, attribute it, and
1591 // complete class name to be fully qualified
1592 JCExpression clazz = tree.clazz; // Class field following new
1593 JCExpression clazzid = // Identifier in class field
1594 (clazz.getTag() == JCTree.Tag.TYPEAPPLY)
1595 ? ((JCTypeApply) clazz).clazz
1596 : clazz;
1597
1598 JCExpression clazzid1 = clazzid; // The same in fully qualified form
1599
1600 if (tree.encl != null) {
1601 // We are seeing a qualified new, of the form
1602 // <expr>.new C <...> (...) ...
1603 // In this case, we let clazz stand for the name of the
1604 // allocated class C prefixed with the type of the qualifier
1605 // expression, so that we can
1606 // resolve it with standard techniques later. I.e., if
1607 // <expr> has type T, then <expr>.new C <...> (...)
1608 // yields a clazz T.C.
1609 Type encltype = chk.checkRefType(tree.encl.pos(),
1610 attribExpr(tree.encl, env));
1611 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1612 ((JCIdent) clazzid).name);
1613 if (clazz.getTag() == JCTree.Tag.TYPEAPPLY)
1614 clazz = make.at(tree.pos).
1615 TypeApply(clazzid1,
1616 ((JCTypeApply) clazz).arguments);
1617 else
1618 clazz = clazzid1;
1619 }
1620
1621 // Attribute clazz expression and store
1622 // symbol + type back into the attributed tree.
1623 Type clazztype = attribType(clazz, env);
1624 Pair<Scope,Scope> mapping = getSyntheticScopeMapping(clazztype);
1625 clazztype = chk.checkDiamond(tree, clazztype);
1626 chk.validate(clazz, localEnv);
1627 if (tree.encl != null) {
1628 // We have to work in this case to store
1629 // symbol + type back into the attributed tree.
1630 tree.clazz.type = clazztype;
1631 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1632 clazzid.type = ((JCIdent) clazzid).sym.type;
1633 if (!clazztype.isErroneous()) {
1634 if (cdef != null && clazztype.tsym.isInterface()) {
1635 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1636 } else if (clazztype.tsym.isStatic()) {
1637 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1638 }
1639 }
1640 } else if (!clazztype.tsym.isInterface() &&
1641 clazztype.getEnclosingType().tag == CLASS) {
1642 // Check for the existence of an apropos outer instance
1643 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1644 }
1645
1646 // Attribute constructor arguments.
1647 List<Type> argtypes = attribArgs(tree.args, localEnv);
1648 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1649
1650 if (TreeInfo.isDiamond(tree) && !clazztype.isErroneous()) {
1651 clazztype = attribDiamond(localEnv, tree, clazztype, mapping, argtypes, typeargtypes);
1652 clazz.type = clazztype;
1653 } else if (allowDiamondFinder &&
1654 tree.def == null &&
1655 !clazztype.isErroneous() &&
1656 clazztype.getTypeArguments().nonEmpty() &&
1657 findDiamonds) {
1658 boolean prevDeferDiags = log.deferDiagnostics;
1659 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
1660 Type inferred = null;
1661 try {
1662 //disable diamond-related diagnostics
1663 log.deferDiagnostics = true;
1664 log.deferredDiagnostics = ListBuffer.lb();
1665 inferred = attribDiamond(localEnv,
1666 tree,
1667 clazztype,
1668 mapping,
1669 argtypes,
1670 typeargtypes);
1671 }
1672 finally {
1673 log.deferDiagnostics = prevDeferDiags;
1674 log.deferredDiagnostics = prevDeferredDiags;
1675 }
1676 if (inferred != null &&
1677 !inferred.isErroneous() &&
1678 inferred.tag == CLASS &&
1679 types.isAssignable(inferred, pt.tag == NONE ? clazztype : pt, Warner.noWarnings)) {
1680 String key = types.isSameType(clazztype, inferred) ?
1681 "diamond.redundant.args" :
1682 "diamond.redundant.args.1";
1683 log.warning(tree.clazz.pos(), key, clazztype, inferred);
1684 }
1685 }
1686
1687 // If we have made no mistakes in the class type...
1688 if (clazztype.tag == CLASS) {
1689 // Enums may not be instantiated except implicitly
1690 if (allowEnums &&
1691 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1692 (env.tree.getTag() != JCTree.Tag.VARDEF ||
1693 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1694 ((JCVariableDecl) env.tree).init != tree))
1695 log.error(tree.pos(), "enum.cant.be.instantiated");
1696 // Check that class is not abstract
1697 if (cdef == null &&
1698 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1699 log.error(tree.pos(), "abstract.cant.be.instantiated",
1700 clazztype.tsym);
1701 } else if (cdef != null && clazztype.tsym.isInterface()) {
1702 // Check that no constructor arguments are given to
1703 // anonymous classes implementing an interface
1704 if (!argtypes.isEmpty())
1705 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1706
1707 if (!typeargtypes.isEmpty())
1708 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1709
1710 // Error recovery: pretend no arguments were supplied.
1711 argtypes = List.nil();
1712 typeargtypes = List.nil();
1713 }
1714
1715 // Resolve the called constructor under the assumption
1716 // that we are referring to a superclass instance of the
1717 // current instance (JLS ???).
1718 else {
1719 //the following code alters some of the fields in the current
1720 //AttrContext - hence, the current context must be dup'ed in
1721 //order to avoid downstream failures
1722 Env<AttrContext> rsEnv = localEnv.dup(tree);
1723 rsEnv.info.selectSuper = cdef != null;
1724 rsEnv.info.varArgs = false;
1725 tree.constructor = rs.resolveConstructor(
1726 tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
1727 tree.constructorType = tree.constructor.type.isErroneous() ?
1728 syms.errType :
1729 checkMethod(clazztype,
1730 tree.constructor,
1731 rsEnv,
1732 tree.args,
1733 argtypes,
1734 typeargtypes,
1735 rsEnv.info.varArgs);
1736 if (rsEnv.info.varArgs)
1737 Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
1738 }
1739
1740 if (cdef != null) {
1741 // We are seeing an anonymous class instance creation.
1742 // In this case, the class instance creation
1743 // expression
1744 //
1745 // E.new <typeargs1>C<typargs2>(args) { ... }
1746 //
1747 // is represented internally as
1748 //
1749 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1750 //
1751 // This expression is then *transformed* as follows:
1752 //
1753 // (1) add a STATIC flag to the class definition
1754 // if the current environment is static
1755 // (2) add an extends or implements clause
1756 // (3) add a constructor.
1757 //
1758 // For instance, if C is a class, and ET is the type of E,
1759 // the expression
1760 //
1761 // E.new <typeargs1>C<typargs2>(args) { ... }
1762 //
1763 // is translated to (where X is a fresh name and typarams is the
1764 // parameter list of the super constructor):
1765 //
1766 // new <typeargs1>X(<*nullchk*>E, args) where
1767 // X extends C<typargs2> {
1768 // <typarams> X(ET e, args) {
1769 // e.<typeargs1>super(args)
1770 // }
1771 // ...
1772 // }
1773 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1774
1775 if (clazztype.tsym.isInterface()) {
1776 cdef.implementing = List.of(clazz);
1777 } else {
1778 cdef.extending = clazz;
1779 }
1780
1781 attribStat(cdef, localEnv);
1782
1783 // If an outer instance is given,
1784 // prefix it to the constructor arguments
1785 // and delete it from the new expression
1786 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1787 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1788 argtypes = argtypes.prepend(tree.encl.type);
1789 tree.encl = null;
1790 }
1791
1792 // Reassign clazztype and recompute constructor.
1793 clazztype = cdef.sym.type;
1794 boolean useVarargs = tree.varargsElement != null;
1795 Symbol sym = rs.resolveConstructor(
1796 tree.pos(), localEnv, clazztype, argtypes,
1797 typeargtypes, true, useVarargs);
1798 Assert.check(sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous());
1799 tree.constructor = sym;
1800 if (tree.constructor.kind > ERRONEOUS) {
1801 tree.constructorType = syms.errType;
1802 }
1803 else {
1804 tree.constructorType = checkMethod(clazztype,
1805 tree.constructor,
1806 localEnv,
1807 tree.args,
1808 argtypes,
1809 typeargtypes,
1810 useVarargs);
1811 }
1812 }
1813
1814 if (tree.constructor != null && tree.constructor.kind == MTH)
1815 owntype = clazztype;
1816 }
1817 result = check(tree, owntype, VAL, pkind, pt);
1818 chk.validate(tree.typeargs, localEnv);
1819 }
1820
1821 Type attribDiamond(Env<AttrContext> env,
1822 JCNewClass tree,
1823 Type clazztype,
1824 Pair<Scope, Scope> mapping,
1825 List<Type> argtypes,
1826 List<Type> typeargtypes) {
1827 if (clazztype.isErroneous() ||
1828 clazztype.isInterface() ||
1829 mapping == erroneousMapping) {
1830 //if the type of the instance creation expression is erroneous,
1831 //or if it's an interface, or if something prevented us to form a valid
1832 //mapping, return the (possibly erroneous) type unchanged
1833 return clazztype;
1834 }
1835
1836 //dup attribution environment and augment the set of inference variables
1837 Env<AttrContext> localEnv = env.dup(tree);
1838 localEnv.info.tvars = clazztype.tsym.type.getTypeArguments();
1839
1840 //if the type of the instance creation expression is a class type
1841 //apply method resolution inference (JLS 15.12.2.7). The return type
1842 //of the resolved constructor will be a partially instantiated type
1843 ((ClassSymbol) clazztype.tsym).members_field = mapping.snd;
1844 Symbol constructor;
1845 try {
1846 constructor = rs.resolveDiamond(tree.pos(),
1847 localEnv,
1848 clazztype,
1849 argtypes,
1850 typeargtypes);
1851 } finally {
1852 ((ClassSymbol) clazztype.tsym).members_field = mapping.fst;
1853 }
1854 if (constructor.kind == MTH) {
1855 ClassType ct = new ClassType(clazztype.getEnclosingType(),
1856 clazztype.tsym.type.getTypeArguments(),
1857 clazztype.tsym);
1858 clazztype = checkMethod(ct,
1859 constructor,
1860 localEnv,
1861 tree.args,
1862 argtypes,
1863 typeargtypes,
1864 localEnv.info.varArgs).getReturnType();
1865 } else {
1866 clazztype = syms.errType;
1867 }
1868
1869 if (clazztype.tag == FORALL && !pt.isErroneous()) {
1870 //if the resolved constructor's return type has some uninferred
1871 //type-variables, infer them using the expected type and declared
1872 //bounds (JLS 15.12.2.8).
1873 try {
1874 clazztype = infer.instantiateExpr((ForAll) clazztype,
1875 pt.tag == NONE ? syms.objectType : pt,
1876 Warner.noWarnings);
1877 } catch (Infer.InferenceException ex) {
1878 //an error occurred while inferring uninstantiated type-variables
1879 log.error(tree.clazz.pos(),
1880 "cant.apply.diamond.1",
1881 diags.fragment("diamond", clazztype.tsym),
1882 ex.diagnostic);
1883 }
1884 }
1885 return chk.checkClassType(tree.clazz.pos(),
1886 clazztype,
1887 true);
1888 }
1889
1890 /** Creates a synthetic scope containing fake generic constructors.
1891 * Assuming that the original scope contains a constructor of the kind:
1892 * Foo(X x, Y y), where X,Y are class type-variables declared in Foo,
1893 * the synthetic scope is added a generic constructor of the kind:
1894 * <X,Y>Foo<X,Y>(X x, Y y). This is crucial in order to enable diamond
1895 * inference. The inferred return type of the synthetic constructor IS
1896 * the inferred type for the diamond operator.
1897 */
1898 private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype) {
1899 if (ctype.tag != CLASS) {
1900 return erroneousMapping;
1901 }
1902
1903 Pair<Scope, Scope> mapping =
1904 new Pair<Scope, Scope>(ctype.tsym.members(), new Scope(ctype.tsym));
1905
1906 //for each constructor in the original scope, create a synthetic constructor
1907 //whose return type is the type of the class in which the constructor is
1908 //declared, and insert it into the new scope.
1909 for (Scope.Entry e = mapping.fst.lookup(names.init);
1910 e.scope != null;
1911 e = e.next()) {
1912 Type synthRestype = new ClassType(ctype.getEnclosingType(),
1913 ctype.tsym.type.getTypeArguments(),
1914 ctype.tsym);
1915 MethodSymbol synhConstr = new MethodSymbol(e.sym.flags(),
1916 names.init,
1917 types.createMethodTypeWithReturn(e.sym.type, synthRestype),
1918 e.sym.owner);
1919 mapping.snd.enter(synhConstr);
1920 }
1921 return mapping;
1922 }
1923
1924 private final Pair<Scope,Scope> erroneousMapping = new Pair<Scope,Scope>(null, null);
1925
1926 /** Make an attributed null check tree.
1927 */
1928 public JCExpression makeNullCheck(JCExpression arg) {
1929 // optimization: X.this is never null; skip null check
1930 Name name = TreeInfo.name(arg);
1931 if (name == names._this || name == names._super) return arg;
1932
1933 JCTree.Tag optag = JCTree.Tag.NULLCHK;
1934 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1935 tree.operator = syms.nullcheck;
1936 tree.type = arg.type;
1937 return tree;
1938 }
1939
1940 public void visitNewArray(JCNewArray tree) {
1941 Type owntype = types.createErrorType(tree.type);
1942 Type elemtype;
1943 if (tree.elemtype != null) {
1944 elemtype = attribType(tree.elemtype, env);
1945 chk.validate(tree.elemtype, env);
1946 owntype = elemtype;
1947 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1948 attribExpr(l.head, env, syms.intType);
1949 owntype = new ArrayType(owntype, syms.arrayClass);
1950 }
1951 } else {
1952 // we are seeing an untyped aggregate { ... }
1953 // this is allowed only if the prototype is an array
1954 if (pt.tag == ARRAY) {
1955 elemtype = types.elemtype(pt);
1956 } else {
1957 if (pt.tag != ERROR) {
1958 log.error(tree.pos(), "illegal.initializer.for.type",
1959 pt);
1960 }
1961 elemtype = types.createErrorType(pt);
1962 }
1963 }
1964 if (tree.elems != null) {
1965 attribExprs(tree.elems, env, elemtype);
1966 owntype = new ArrayType(elemtype, syms.arrayClass);
1967 }
1968 if (!types.isReifiable(elemtype))
1969 log.error(tree.pos(), "generic.array.creation");
1970 result = check(tree, owntype, VAL, pkind, pt);
1971 }
1972
1973 public void visitParens(JCParens tree) {
1974 Type owntype = attribTree(tree.expr, env, pkind, pt);
1975 result = check(tree, owntype, pkind, pkind, pt);
1976 Symbol sym = TreeInfo.symbol(tree);
1977 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1978 log.error(tree.pos(), "illegal.start.of.type");
1979 }
1980
1981 public void visitAssign(JCAssign tree) {
1982 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1983 Type capturedType = capture(owntype);
1984 attribExpr(tree.rhs, env, owntype);
1985 result = check(tree, capturedType, VAL, pkind, pt);
1986 }
1987
1988 public void visitAssignop(JCAssignOp tree) {
1989 // Attribute arguments.
1990 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
1991 Type operand = attribExpr(tree.rhs, env);
1992 // Find operator.
1993 Symbol operator = tree.operator = rs.resolveBinaryOperator(
1994 tree.pos(), tree.getTag().noAssignOp(), env,
1995 owntype, operand);
1996
1997 if (operator.kind == MTH &&
1998 !owntype.isErroneous() &&
1999 !operand.isErroneous()) {
2000 chk.checkOperator(tree.pos(),
2001 (OperatorSymbol)operator,
2002 tree.getTag().noAssignOp(),
2003 owntype,
2004 operand);
2005 chk.checkDivZero(tree.rhs.pos(), operator, operand);
2006 chk.checkCastable(tree.rhs.pos(),
2007 operator.type.getReturnType(),
2008 owntype);
2009 }
2010 result = check(tree, owntype, VAL, pkind, pt);
2011 }
2012
2013 public void visitUnary(JCUnary tree) {
2014 // Attribute arguments.
2015 Type argtype = (JCTree.Tag.PREINC.ordinal() <= tree.getTag().ordinal() &&
2016 tree.getTag().ordinal() <= JCTree.Tag.POSTDEC.ordinal())
2017 ? attribTree(tree.arg, env, VAR, Type.noType)
2018 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
2019
2020 // Find operator.
2021 Symbol operator = tree.operator =
2022 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
2023
2024 Type owntype = types.createErrorType(tree.type);
2025 if (operator.kind == MTH &&
2026 !argtype.isErroneous()) {
2027 owntype = (JCTree.Tag.PREINC.ordinal() <= tree.getTag().ordinal() &&
2028 tree.getTag().ordinal() <= JCTree.Tag.POSTDEC.ordinal())
2029 ? tree.arg.type
2030 : operator.type.getReturnType();
2031 int opc = ((OperatorSymbol)operator).opcode;
2032
2033 // If the argument is constant, fold it.
2034 if (argtype.constValue() != null) {
2035 Type ctype = cfolder.fold1(opc, argtype);
2036 if (ctype != null) {
2037 owntype = cfolder.coerce(ctype, owntype);
2038
2039 // Remove constant types from arguments to
2040 // conserve space. The parser will fold concatenations
2041 // of string literals; the code here also
2042 // gets rid of intermediate results when some of the
2043 // operands are constant identifiers.
2044 if (tree.arg.type.tsym == syms.stringType.tsym) {
2045 tree.arg.type = syms.stringType;
2046 }
2047 }
2048 }
2049 }
2050 result = check(tree, owntype, VAL, pkind, pt);
2051 }
2052
2053 public void visitBinary(JCBinary tree) {
2054 // Attribute arguments.
2055 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
2056 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
2057
2058 // Find operator.
2059 Symbol operator = tree.operator =
2060 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
2061
2062 Type owntype = types.createErrorType(tree.type);
2063 if (operator.kind == MTH &&
2064 !left.isErroneous() &&
2065 !right.isErroneous()) {
2066 owntype = operator.type.getReturnType();
2067 int opc = chk.checkOperator(tree.lhs.pos(),
2068 (OperatorSymbol)operator,
2069 tree.getTag(),
2070 left,
2071 right);
2072
2073 // If both arguments are constants, fold them.
2074 if (left.constValue() != null && right.constValue() != null) {
2075 Type ctype = cfolder.fold2(opc, left, right);
2076 if (ctype != null) {
2077 owntype = cfolder.coerce(ctype, owntype);
2078
2079 // Remove constant types from arguments to
2080 // conserve space. The parser will fold concatenations
2081 // of string literals; the code here also
2082 // gets rid of intermediate results when some of the
2083 // operands are constant identifiers.
2084 if (tree.lhs.type.tsym == syms.stringType.tsym) {
2085 tree.lhs.type = syms.stringType;
2086 }
2087 if (tree.rhs.type.tsym == syms.stringType.tsym) {
2088 tree.rhs.type = syms.stringType;
2089 }
2090 }
2091 }
2092
2093 // Check that argument types of a reference ==, != are
2094 // castable to each other, (JLS???).
2095 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
2096 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
2097 log.error(tree.pos(), "incomparable.types", left, right);
2098 }
2099 }
2100
2101 chk.checkDivZero(tree.rhs.pos(), operator, right);
2102 }
2103 result = check(tree, owntype, VAL, pkind, pt);
2104 }
2105
2106 public void visitTypeCast(JCTypeCast tree) {
2107 Type clazztype = attribType(tree.clazz, env);
2108 chk.validate(tree.clazz, env, false);
2109 //a fresh environment is required for 292 inference to work properly ---
2110 //see Infer.instantiatePolymorphicSignatureInstance()
2111 Env<AttrContext> localEnv = env.dup(tree);
2112 Type exprtype = attribExpr(tree.expr, localEnv, Infer.anyPoly);
2113 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2114 if (exprtype.constValue() != null)
2115 owntype = cfolder.coerce(exprtype, owntype);
2116 result = check(tree, capture(owntype), VAL, pkind, pt);
2117 }
2118
2119 public void visitTypeTest(JCInstanceOf tree) {
2120 Type exprtype = chk.checkNullOrRefType(
2121 tree.expr.pos(), attribExpr(tree.expr, env));
2122 Type clazztype = chk.checkReifiableReferenceType(
2123 tree.clazz.pos(), attribType(tree.clazz, env));
2124 chk.validate(tree.clazz, env, false);
2125 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2126 result = check(tree, syms.booleanType, VAL, pkind, pt);
2127 }
2128
2129 public void visitIndexed(JCArrayAccess tree) {
2130 Type owntype = types.createErrorType(tree.type);
2131 Type atype = attribExpr(tree.indexed, env);
2132 attribExpr(tree.index, env, syms.intType);
2133 if (types.isArray(atype))
2134 owntype = types.elemtype(atype);
2135 else if (atype.tag != ERROR)
2136 log.error(tree.pos(), "array.req.but.found", atype);
2137 if ((pkind & VAR) == 0) owntype = capture(owntype);
2138 result = check(tree, owntype, VAR, pkind, pt);
2139 }
2140
2141 public void visitIdent(JCIdent tree) {
2142 Symbol sym;
2143 boolean varArgs = false;
2144
2145 // Find symbol
2146 if (pt.tag == METHOD || pt.tag == FORALL) {
2147 // If we are looking for a method, the prototype `pt' will be a
2148 // method type with the type of the call's arguments as parameters.
2149 env.info.varArgs = false;
2150 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
2151 varArgs = env.info.varArgs;
2152 } else if (tree.sym != null && tree.sym.kind != VAR) {
2153 sym = tree.sym;
2154 } else {
2155 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
2156 }
2157 tree.sym = sym;
2158
2159 // (1) Also find the environment current for the class where
2160 // sym is defined (`symEnv').
2161 // Only for pre-tiger versions (1.4 and earlier):
2162 // (2) Also determine whether we access symbol out of an anonymous
2163 // class in a this or super call. This is illegal for instance
2164 // members since such classes don't carry a this$n link.
2165 // (`noOuterThisPath').
2166 Env<AttrContext> symEnv = env;
2167 boolean noOuterThisPath = false;
2168 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
2169 (sym.kind & (VAR | MTH | TYP)) != 0 &&
2170 sym.owner.kind == TYP &&
2171 tree.name != names._this && tree.name != names._super) {
2172
2173 // Find environment in which identifier is defined.
2174 while (symEnv.outer != null &&
2175 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
2176 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
2177 noOuterThisPath = !allowAnonOuterThis;
2178 symEnv = symEnv.outer;
2179 }
2180 }
2181
2182 // If symbol is a variable, ...
2183 if (sym.kind == VAR) {
2184 VarSymbol v = (VarSymbol)sym;
2185
2186 // ..., evaluate its initializer, if it has one, and check for
2187 // illegal forward reference.
2188 checkInit(tree, env, v, false);
2189
2190 // If symbol is a local variable accessed from an embedded
2191 // inner class check that it is final.
2192 if (v.owner.kind == MTH &&
2193 v.owner != env.info.scope.owner &&
2194 (v.flags_field & FINAL) == 0) {
2195 log.error(tree.pos(),
2196 "local.var.accessed.from.icls.needs.final",
2197 v);
2198 }
2199
2200 // If we are expecting a variable (as opposed to a value), check
2201 // that the variable is assignable in the current environment.
2202 if (pkind == VAR)
2203 checkAssignable(tree.pos(), v, null, env);
2204 }
2205
2206 // In a constructor body,
2207 // if symbol is a field or instance method, check that it is
2208 // not accessed before the supertype constructor is called.
2209 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
2210 (sym.kind & (VAR | MTH)) != 0 &&
2211 sym.owner.kind == TYP &&
2212 (sym.flags() & STATIC) == 0) {
2213 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
2214 }
2215 Env<AttrContext> env1 = env;
2216 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
2217 // If the found symbol is inaccessible, then it is
2218 // accessed through an enclosing instance. Locate this
2219 // enclosing instance:
2220 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
2221 env1 = env1.outer;
2222 }
2223 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
2224 }
2225
2226 public void visitSelect(JCFieldAccess tree) {
2227 // Determine the expected kind of the qualifier expression.
2228 int skind = 0;
2229 if (tree.name == names._this || tree.name == names._super ||
2230 tree.name == names._class)
2231 {
2232 skind = TYP;
2233 } else {
2234 if ((pkind & PCK) != 0) skind = skind | PCK;
2235 if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
2236 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
2237 }
2238
2239 // Attribute the qualifier expression, and determine its symbol (if any).
2240 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
2241 if ((pkind & (PCK | TYP)) == 0)
2242 site = capture(site); // Capture field access
2243
2244 // don't allow T.class T[].class, etc
2245 if (skind == TYP) {
2246 Type elt = site;
2247 while (elt.tag == ARRAY)
2248 elt = ((ArrayType)elt).elemtype;
2249 if (elt.tag == TYPEVAR) {
2250 log.error(tree.pos(), "type.var.cant.be.deref");
2251 result = types.createErrorType(tree.type);
2252 return;
2253 }
2254 }
2255
2256 // If qualifier symbol is a type or `super', assert `selectSuper'
2257 // for the selection. This is relevant for determining whether
2258 // protected symbols are accessible.
2259 Symbol sitesym = TreeInfo.symbol(tree.selected);
2260 boolean selectSuperPrev = env.info.selectSuper;
2261 env.info.selectSuper =
2262 sitesym != null &&
2263 sitesym.name == names._super;
2264
2265 // If selected expression is polymorphic, strip
2266 // type parameters and remember in env.info.tvars, so that
2267 // they can be added later (in Attr.checkId and Infer.instantiateMethod).
2268 if (tree.selected.type.tag == FORALL) {
2269 ForAll pstype = (ForAll)tree.selected.type;
2270 env.info.tvars = pstype.tvars;
2271 site = tree.selected.type = pstype.qtype;
2272 }
2273
2274 // Determine the symbol represented by the selection.
2275 env.info.varArgs = false;
2276 Symbol sym = selectSym(tree, sitesym, site, env, pt, pkind);
2277 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
2278 site = capture(site);
2279 sym = selectSym(tree, sitesym, site, env, pt, pkind);
2280 }
2281 boolean varArgs = env.info.varArgs;
2282 tree.sym = sym;
2283
2284 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
2285 while (site.tag == TYPEVAR) site = site.getUpperBound();
2286 site = capture(site);
2287 }
2288
2289 // If that symbol is a variable, ...
2290 if (sym.kind == VAR) {
2291 VarSymbol v = (VarSymbol)sym;
2292
2293 // ..., evaluate its initializer, if it has one, and check for
2294 // illegal forward reference.
2295 checkInit(tree, env, v, true);
2296
2297 // If we are expecting a variable (as opposed to a value), check
2298 // that the variable is assignable in the current environment.
2299 if (pkind == VAR)
2300 checkAssignable(tree.pos(), v, tree.selected, env);
2301 }
2302
2303 if (sitesym != null &&
2304 sitesym.kind == VAR &&
2305 ((VarSymbol)sitesym).isResourceVariable() &&
2306 sym.kind == MTH &&
2307 sym.name.equals(names.close) &&
2308 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
2309 env.info.lint.isEnabled(LintCategory.TRY)) {
2310 log.warning(LintCategory.TRY, tree, "try.explicit.close.call");
2311 }
2312
2313 // Disallow selecting a type from an expression
2314 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
2315 tree.type = check(tree.selected, pt,
2316 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
2317 }
2318
2319 if (isType(sitesym)) {
2320 if (sym.name == names._this) {
2321 // If `C' is the currently compiled class, check that
2322 // C.this' does not appear in a call to a super(...)
2323 if (env.info.isSelfCall &&
2324 site.tsym == env.enclClass.sym) {
2325 chk.earlyRefError(tree.pos(), sym);
2326 }
2327 } else {
2328 // Check if type-qualified fields or methods are static (JLS)
2329 if ((sym.flags() & STATIC) == 0 &&
2330 sym.name != names._super &&
2331 (sym.kind == VAR || sym.kind == MTH)) {
2332 rs.access(rs.new StaticError(sym),
2333 tree.pos(), site, sym.name, true);
2334 }
2335 }
2336 } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
2337 // If the qualified item is not a type and the selected item is static, report
2338 // a warning. Make allowance for the class of an array type e.g. Object[].class)
2339 chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
2340 }
2341
2342 // If we are selecting an instance member via a `super', ...
2343 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
2344
2345 // Check that super-qualified symbols are not abstract (JLS)
2346 rs.checkNonAbstract(tree.pos(), sym);
2347
2348 if (site.isRaw()) {
2349 // Determine argument types for site.
2350 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
2351 if (site1 != null) site = site1;
2352 }
2353 }
2354
2355 env.info.selectSuper = selectSuperPrev;
2356 result = checkId(tree, site, sym, env, pkind, pt, varArgs);
2357 env.info.tvars = List.nil();
2358 }
2359 //where
2360 /** Determine symbol referenced by a Select expression,
2361 *
2362 * @param tree The select tree.
2363 * @param site The type of the selected expression,
2364 * @param env The current environment.
2365 * @param pt The current prototype.
2366 * @param pkind The expected kind(s) of the Select expression.
2367 */
2368 private Symbol selectSym(JCFieldAccess tree,
2369 Type site,
2370 Env<AttrContext> env,
2371 Type pt,
2372 int pkind) {
2373 return selectSym(tree, site.tsym, site, env, pt, pkind);
2374 }
2375 private Symbol selectSym(JCFieldAccess tree,
2376 Symbol location,
2377 Type site,
2378 Env<AttrContext> env,
2379 Type pt,
2380 int pkind) {
2381 DiagnosticPosition pos = tree.pos();
2382 Name name = tree.name;
2383 switch (site.tag) {
2384 case PACKAGE:
2385 return rs.access(
2386 rs.findIdentInPackage(env, site.tsym, name, pkind),
2387 pos, location, site, name, true);
2388 case ARRAY:
2389 case CLASS:
2390 if (pt.tag == METHOD || pt.tag == FORALL) {
2391 return rs.resolveQualifiedMethod(
2392 pos, env, location, site, name, pt.getParameterTypes(), pt.getTypeArguments());
2393 } else if (name == names._this || name == names._super) {
2394 return rs.resolveSelf(pos, env, site.tsym, name);
2395 } else if (name == names._class) {
2396 // In this case, we have already made sure in
2397 // visitSelect that qualifier expression is a type.
2398 Type t = syms.classType;
2399 List<Type> typeargs = allowGenerics
2400 ? List.of(types.erasure(site))
2401 : List.<Type>nil();
2402 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
2403 return new VarSymbol(
2404 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2405 } else {
2406 // We are seeing a plain identifier as selector.
2407 Symbol sym = rs.findIdentInType(env, site, name, pkind);
2408 if ((pkind & ERRONEOUS) == 0)
2409 sym = rs.access(sym, pos, location, site, name, true);
2410 return sym;
2411 }
2412 case WILDCARD:
2413 throw new AssertionError(tree);
2414 case TYPEVAR:
2415 // Normally, site.getUpperBound() shouldn't be null.
2416 // It should only happen during memberEnter/attribBase
2417 // when determining the super type which *must* beac
2418 // done before attributing the type variables. In
2419 // other words, we are seeing this illegal program:
2420 // class B<T> extends A<T.foo> {}
2421 Symbol sym = (site.getUpperBound() != null)
2422 ? selectSym(tree, location, capture(site.getUpperBound()), env, pt, pkind)
2423 : null;
2424 if (sym == null) {
2425 log.error(pos, "type.var.cant.be.deref");
2426 return syms.errSymbol;
2427 } else {
2428 Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
2429 rs.new AccessError(env, site, sym) :
2430 sym;
2431 rs.access(sym2, pos, location, site, name, true);
2432 return sym;
2433 }
2434 case ERROR:
2435 // preserve identifier names through errors
2436 return types.createErrorType(name, site.tsym, site).tsym;
2437 default:
2438 // The qualifier expression is of a primitive type -- only
2439 // .class is allowed for these.
2440 if (name == names._class) {
2441 // In this case, we have already made sure in Select that
2442 // qualifier expression is a type.
2443 Type t = syms.classType;
2444 Type arg = types.boxedClass(site).type;
2445 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2446 return new VarSymbol(
2447 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2448 } else {
2449 log.error(pos, "cant.deref", site);
2450 return syms.errSymbol;
2451 }
2452 }
2453 }
2454
2455 /** Determine type of identifier or select expression and check that
2456 * (1) the referenced symbol is not deprecated
2457 * (2) the symbol's type is safe (@see checkSafe)
2458 * (3) if symbol is a variable, check that its type and kind are
2459 * compatible with the prototype and protokind.
2460 * (4) if symbol is an instance field of a raw type,
2461 * which is being assigned to, issue an unchecked warning if its
2462 * type changes under erasure.
2463 * (5) if symbol is an instance method of a raw type, issue an
2464 * unchecked warning if its argument types change under erasure.
2465 * If checks succeed:
2466 * If symbol is a constant, return its constant type
2467 * else if symbol is a method, return its result type
2468 * otherwise return its type.
2469 * Otherwise return errType.
2470 *
2471 * @param tree The syntax tree representing the identifier
2472 * @param site If this is a select, the type of the selected
2473 * expression, otherwise the type of the current class.
2474 * @param sym The symbol representing the identifier.
2475 * @param env The current environment.
2476 * @param pkind The set of expected kinds.
2477 * @param pt The expected type.
2478 */
2479 Type checkId(JCTree tree,
2480 Type site,
2481 Symbol sym,
2482 Env<AttrContext> env,
2483 int pkind,
2484 Type pt,
2485 boolean useVarargs) {
2486 if (pt.isErroneous()) return types.createErrorType(site);
2487 Type owntype; // The computed type of this identifier occurrence.
2488 switch (sym.kind) {
2489 case TYP:
2490 // For types, the computed type equals the symbol's type,
2491 // except for two situations:
2492 owntype = sym.type;
2493 if (owntype.tag == CLASS) {
2494 Type ownOuter = owntype.getEnclosingType();
2495
2496 // (a) If the symbol's type is parameterized, erase it
2497 // because no type parameters were given.
2498 // We recover generic outer type later in visitTypeApply.
2499 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2500 owntype = types.erasure(owntype);
2501 }
2502
2503 // (b) If the symbol's type is an inner class, then
2504 // we have to interpret its outer type as a superclass
2505 // of the site type. Example:
2506 //
2507 // class Tree<A> { class Visitor { ... } }
2508 // class PointTree extends Tree<Point> { ... }
2509 // ...PointTree.Visitor...
2510 //
2511 // Then the type of the last expression above is
2512 // Tree<Point>.Visitor.
2513 else if (ownOuter.tag == CLASS && site != ownOuter) {
2514 Type normOuter = site;
2515 if (normOuter.tag == CLASS)
2516 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2517 if (normOuter == null) // perhaps from an import
2518 normOuter = types.erasure(ownOuter);
2519 if (normOuter != ownOuter)
2520 owntype = new ClassType(
2521 normOuter, List.<Type>nil(), owntype.tsym);
2522 }
2523 }
2524 break;
2525 case VAR:
2526 VarSymbol v = (VarSymbol)sym;
2527 // Test (4): if symbol is an instance field of a raw type,
2528 // which is being assigned to, issue an unchecked warning if
2529 // its type changes under erasure.
2530 if (allowGenerics &&
2531 pkind == VAR &&
2532 v.owner.kind == TYP &&
2533 (v.flags() & STATIC) == 0 &&
2534 (site.tag == CLASS || site.tag == TYPEVAR)) {
2535 Type s = types.asOuterSuper(site, v.owner);
2536 if (s != null &&
2537 s.isRaw() &&
2538 !types.isSameType(v.type, v.erasure(types))) {
2539 chk.warnUnchecked(tree.pos(),
2540 "unchecked.assign.to.var",
2541 v, s);
2542 }
2543 }
2544 // The computed type of a variable is the type of the
2545 // variable symbol, taken as a member of the site type.
2546 owntype = (sym.owner.kind == TYP &&
2547 sym.name != names._this && sym.name != names._super)
2548 ? types.memberType(site, sym)
2549 : sym.type;
2550
2551 if (env.info.tvars.nonEmpty()) {
2552 Type owntype1 = new ForAll(env.info.tvars, owntype);
2553 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2554 if (!owntype.contains(l.head)) {
2555 log.error(tree.pos(), "undetermined.type", owntype1);
2556 owntype1 = types.createErrorType(owntype1);
2557 }
2558 owntype = owntype1;
2559 }
2560
2561 // If the variable is a constant, record constant value in
2562 // computed type.
2563 if (v.getConstValue() != null && isStaticReference(tree))
2564 owntype = owntype.constType(v.getConstValue());
2565
2566 if (pkind == VAL) {
2567 owntype = capture(owntype); // capture "names as expressions"
2568 }
2569 break;
2570 case MTH: {
2571 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2572 owntype = checkMethod(site, sym, env, app.args,
2573 pt.getParameterTypes(), pt.getTypeArguments(),
2574 env.info.varArgs);
2575 break;
2576 }
2577 case PCK: case ERR:
2578 owntype = sym.type;
2579 break;
2580 default:
2581 throw new AssertionError("unexpected kind: " + sym.kind +
2582 " in tree " + tree);
2583 }
2584
2585 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2586 // (for constructors, the error was given when the constructor was
2587 // resolved)
2588
2589 if (sym.name != names.init) {
2590 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
2591 chk.checkSunAPI(tree.pos(), sym);
2592 }
2593
2594 // Test (3): if symbol is a variable, check that its type and
2595 // kind are compatible with the prototype and protokind.
2596 return check(tree, owntype, sym.kind, pkind, pt);
2597 }
2598
2599 /** Check that variable is initialized and evaluate the variable's
2600 * initializer, if not yet done. Also check that variable is not
2601 * referenced before it is defined.
2602 * @param tree The tree making up the variable reference.
2603 * @param env The current environment.
2604 * @param v The variable's symbol.
2605 */
2606 private void checkInit(JCTree tree,
2607 Env<AttrContext> env,
2608 VarSymbol v,
2609 boolean onlyWarning) {
2610 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2611 // tree.pos + " " + v.pos + " " +
2612 // Resolve.isStatic(env));//DEBUG
2613
2614 // A forward reference is diagnosed if the declaration position
2615 // of the variable is greater than the current tree position
2616 // and the tree and variable definition occur in the same class
2617 // definition. Note that writes don't count as references.
2618 // This check applies only to class and instance
2619 // variables. Local variables follow different scope rules,
2620 // and are subject to definite assignment checking.
2621 if ((env.info.enclVar == v || v.pos > tree.pos) &&
2622 v.owner.kind == TYP &&
2623 canOwnInitializer(env.info.scope.owner) &&
2624 v.owner == env.info.scope.owner.enclClass() &&
2625 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2626 (env.tree.getTag() != JCTree.Tag.ASSIGN ||
2627 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2628 String suffix = (env.info.enclVar == v) ?
2629 "self.ref" : "forward.ref";
2630 if (!onlyWarning || isStaticEnumField(v)) {
2631 log.error(tree.pos(), "illegal." + suffix);
2632 } else if (useBeforeDeclarationWarning) {
2633 log.warning(tree.pos(), suffix, v);
2634 }
2635 }
2636
2637 v.getConstValue(); // ensure initializer is evaluated
2638
2639 checkEnumInitializer(tree, env, v);
2640 }
2641
2642 /**
2643 * Check for illegal references to static members of enum. In
2644 * an enum type, constructors and initializers may not
2645 * reference its static members unless they are constant.
2646 *
2647 * @param tree The tree making up the variable reference.
2648 * @param env The current environment.
2649 * @param v The variable's symbol.
2650 * @jls section 8.9 Enums
2651 */
2652 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2653 // JLS:
2654 //
2655 // "It is a compile-time error to reference a static field
2656 // of an enum type that is not a compile-time constant
2657 // (15.28) from constructors, instance initializer blocks,
2658 // or instance variable initializer expressions of that
2659 // type. It is a compile-time error for the constructors,
2660 // instance initializer blocks, or instance variable
2661 // initializer expressions of an enum constant e to refer
2662 // to itself or to an enum constant of the same type that
2663 // is declared to the right of e."
2664 if (isStaticEnumField(v)) {
2665 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2666
2667 if (enclClass == null || enclClass.owner == null)
2668 return;
2669
2670 // See if the enclosing class is the enum (or a
2671 // subclass thereof) declaring v. If not, this
2672 // reference is OK.
2673 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2674 return;
2675
2676 // If the reference isn't from an initializer, then
2677 // the reference is OK.
2678 if (!Resolve.isInitializer(env))
2679 return;
2680
2681 log.error(tree.pos(), "illegal.enum.static.ref");
2682 }
2683 }
2684
2685 /** Is the given symbol a static, non-constant field of an Enum?
2686 * Note: enum literals should not be regarded as such
2687 */
2688 private boolean isStaticEnumField(VarSymbol v) {
2689 return Flags.isEnum(v.owner) &&
2690 Flags.isStatic(v) &&
2691 !Flags.isConstant(v) &&
2692 v.name != names._class;
2693 }
2694
2695 /** Can the given symbol be the owner of code which forms part
2696 * if class initialization? This is the case if the symbol is
2697 * a type or field, or if the symbol is the synthetic method.
2698 * owning a block.
2699 */
2700 private boolean canOwnInitializer(Symbol sym) {
2701 return
2702 (sym.kind & (VAR | TYP)) != 0 ||
2703 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2704 }
2705
2706 Warner noteWarner = new Warner();
2707
2708 /**
2709 * Check that method arguments conform to its instantation.
2710 **/
2711 public Type checkMethod(Type site,
2712 Symbol sym,
2713 Env<AttrContext> env,
2714 final List<JCExpression> argtrees,
2715 List<Type> argtypes,
2716 List<Type> typeargtypes,
2717 boolean useVarargs) {
2718 // Test (5): if symbol is an instance method of a raw type, issue
2719 // an unchecked warning if its argument types change under erasure.
2720 if (allowGenerics &&
2721 (sym.flags() & STATIC) == 0 &&
2722 (site.tag == CLASS || site.tag == TYPEVAR)) {
2723 Type s = types.asOuterSuper(site, sym.owner);
2724 if (s != null && s.isRaw() &&
2725 !types.isSameTypes(sym.type.getParameterTypes(),
2726 sym.erasure(types).getParameterTypes())) {
2727 chk.warnUnchecked(env.tree.pos(),
2728 "unchecked.call.mbr.of.raw.type",
2729 sym, s);
2730 }
2731 }
2732
2733 // Compute the identifier's instantiated type.
2734 // For methods, we need to compute the instance type by
2735 // Resolve.instantiate from the symbol's type as well as
2736 // any type arguments and value arguments.
2737 noteWarner.clear();
2738 Type owntype = rs.instantiate(env,
2739 site,
2740 sym,
2741 argtypes,
2742 typeargtypes,
2743 true,
2744 useVarargs,
2745 noteWarner);
2746 boolean warned = noteWarner.hasNonSilentLint(LintCategory.UNCHECKED);
2747
2748 // If this fails, something went wrong; we should not have
2749 // found the identifier in the first place.
2750 if (owntype == null) {
2751 if (!pt.isErroneous())
2752 log.error(env.tree.pos(),
2753 "internal.error.cant.instantiate",
2754 sym, site,
2755 Type.toString(pt.getParameterTypes()));
2756 owntype = types.createErrorType(site);
2757 } else {
2758 // System.out.println("call : " + env.tree);
2759 // System.out.println("method : " + owntype);
2760 // System.out.println("actuals: " + argtypes);
2761 List<Type> formals = owntype.getParameterTypes();
2762 Type last = useVarargs ? formals.last() : null;
2763 if (sym.name==names.init &&
2764 sym.owner == syms.enumSym)
2765 formals = formals.tail.tail;
2766 List<JCExpression> args = argtrees;
2767 while (formals.head != last) {
2768 JCTree arg = args.head;
2769 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2770 assertConvertible(arg, arg.type, formals.head, warn);
2771 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED);
2772 args = args.tail;
2773 formals = formals.tail;
2774 }
2775 if (useVarargs) {
2776 Type varArg = types.elemtype(last);
2777 while (args.tail != null) {
2778 JCTree arg = args.head;
2779 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2780 assertConvertible(arg, arg.type, varArg, warn);
2781 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED);
2782 args = args.tail;
2783 }
2784 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2785 // non-varargs call to varargs method
2786 Type varParam = owntype.getParameterTypes().last();
2787 Type lastArg = argtypes.last();
2788 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2789 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2790 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2791 types.elemtype(varParam),
2792 varParam);
2793 }
2794
2795 if (warned && sym.type.tag == FORALL) {
2796 chk.warnUnchecked(env.tree.pos(),
2797 "unchecked.meth.invocation.applied",
2798 kindName(sym),
2799 sym.name,
2800 rs.methodArguments(sym.type.getParameterTypes()),
2801 rs.methodArguments(argtypes),
2802 kindName(sym.location()),
2803 sym.location());
2804 owntype = new MethodType(owntype.getParameterTypes(),
2805 types.erasure(owntype.getReturnType()),
2806 types.erasure(owntype.getThrownTypes()),
2807 syms.methodClass);
2808 }
2809 if (useVarargs) {
2810 JCTree tree = env.tree;
2811 Type argtype = owntype.getParameterTypes().last();
2812 if (owntype.getReturnType().tag != FORALL || warned) {
2813 chk.checkVararg(env.tree.pos(), owntype.getParameterTypes(), sym);
2814 }
2815 Type elemtype = types.elemtype(argtype);
2816 switch (tree.getTag()) {
2817 case APPLY:
2818 ((JCMethodInvocation) tree).varargsElement = elemtype;
2819 break;
2820 case NEWCLASS:
2821 ((JCNewClass) tree).varargsElement = elemtype;
2822 break;
2823 default:
2824 throw new AssertionError(""+tree);
2825 }
2826 }
2827 }
2828 return owntype;
2829 }
2830
2831 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2832 if (types.isConvertible(actual, formal, warn))
2833 return;
2834
2835 if (formal.isCompound()
2836 && types.isSubtype(actual, types.supertype(formal))
2837 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2838 return;
2839
2840 if (false) {
2841 // TODO: make assertConvertible work
2842 chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal);
2843 throw new AssertionError("Tree: " + tree
2844 + " actual:" + actual
2845 + " formal: " + formal);
2846 }
2847 }
2848
2849 public void visitLiteral(JCLiteral tree) {
2850 result = check(
2851 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2852 }
2853 //where
2854 /** Return the type of a literal with given type tag.
2855 */
2856 Type litType(int tag) {
2857 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2858 }
2859
2860 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2861 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2862 }
2863
2864 public void visitTypeArray(JCArrayTypeTree tree) {
2865 Type etype = attribType(tree.elemtype, env);
2866 Type type = new ArrayType(etype, syms.arrayClass);
2867 result = check(tree, type, TYP, pkind, pt);
2868 }
2869
2870 /** Visitor method for parameterized types.
2871 * Bound checking is left until later, since types are attributed
2872 * before supertype structure is completely known
2873 */
2874 public void visitTypeApply(JCTypeApply tree) {
2875 Type owntype = types.createErrorType(tree.type);
2876
2877 // Attribute functor part of application and make sure it's a class.
2878 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2879
2880 // Attribute type parameters
2881 List<Type> actuals = attribTypes(tree.arguments, env);
2882
2883 if (clazztype.tag == CLASS) {
2884 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2885 if (actuals.isEmpty()) //diamond
2886 actuals = formals;
2887
2888 if (actuals.length() == formals.length()) {
2889 List<Type> a = actuals;
2890 List<Type> f = formals;
2891 while (a.nonEmpty()) {
2892 a.head = a.head.withTypeVar(f.head);
2893 a = a.tail;
2894 f = f.tail;
2895 }
2896 // Compute the proper generic outer
2897 Type clazzOuter = clazztype.getEnclosingType();
2898 if (clazzOuter.tag == CLASS) {
2899 Type site;
2900 JCExpression clazz = TreeInfo.typeIn(tree.clazz);
2901 if (clazz.getTag() == JCTree.Tag.IDENT) {
2902 site = env.enclClass.sym.type;
2903 } else if (clazz.getTag() == JCTree.Tag.SELECT) {
2904 site = ((JCFieldAccess) clazz).selected.type;
2905 } else throw new AssertionError(""+tree);
2906 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2907 if (site.tag == CLASS)
2908 site = types.asOuterSuper(site, clazzOuter.tsym);
2909 if (site == null)
2910 site = types.erasure(clazzOuter);
2911 clazzOuter = site;
2912 }
2913 }
2914 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2915 } else {
2916 if (formals.length() != 0) {
2917 log.error(tree.pos(), "wrong.number.type.args",
2918 Integer.toString(formals.length()));
2919 } else {
2920 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2921 }
2922 owntype = types.createErrorType(tree.type);
2923 }
2924 }
2925 result = check(tree, owntype, TYP, pkind, pt);
2926 }
2927
2928 public void visitTypeUnion(JCTypeUnion tree) {
2929 ListBuffer<Type> multicatchTypes = ListBuffer.lb();
2930 ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
2931 for (JCExpression typeTree : tree.alternatives) {
2932 Type ctype = attribType(typeTree, env);
2933 ctype = chk.checkType(typeTree.pos(),
2934 chk.checkClassType(typeTree.pos(), ctype),
2935 syms.throwableType);
2936 if (!ctype.isErroneous()) {
2937 //check that alternatives of a union type are pairwise
2938 //unrelated w.r.t. subtyping
2939 if (chk.intersects(ctype, multicatchTypes.toList())) {
2940 for (Type t : multicatchTypes) {
2941 boolean sub = types.isSubtype(ctype, t);
2942 boolean sup = types.isSubtype(t, ctype);
2943 if (sub || sup) {
2944 //assume 'a' <: 'b'
2945 Type a = sub ? ctype : t;
2946 Type b = sub ? t : ctype;
2947 log.error(typeTree.pos(), "multicatch.types.must.be.disjoint", a, b);
2948 }
2949 }
2950 }
2951 multicatchTypes.append(ctype);
2952 if (all_multicatchTypes != null)
2953 all_multicatchTypes.append(ctype);
2954 } else {
2955 if (all_multicatchTypes == null) {
2956 all_multicatchTypes = ListBuffer.lb();
2957 all_multicatchTypes.appendList(multicatchTypes);
2958 }
2959 all_multicatchTypes.append(ctype);
2960 }
2961 }
2962 Type t = check(tree, types.lub(multicatchTypes.toList()), TYP, pkind, pt);
2963 if (t.tag == CLASS) {
2964 List<Type> alternatives =
2965 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
2966 t = new UnionClassType((ClassType) t, alternatives);
2967 }
2968 tree.type = result = t;
2969 }
2970
2971 public void visitTypeParameter(JCTypeParameter tree) {
2972 TypeVar a = (TypeVar)tree.type;
2973 Set<Type> boundSet = new HashSet<Type>();
2974 if (a.bound.isErroneous())
2975 return;
2976 List<Type> bs = types.getBounds(a);
2977 if (tree.bounds.nonEmpty()) {
2978 // accept class or interface or typevar as first bound.
2979 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2980 boundSet.add(types.erasure(b));
2981 if (b.isErroneous()) {
2982 a.bound = b;
2983 }
2984 else if (b.tag == TYPEVAR) {
2985 // if first bound was a typevar, do not accept further bounds.
2986 if (tree.bounds.tail.nonEmpty()) {
2987 log.error(tree.bounds.tail.head.pos(),
2988 "type.var.may.not.be.followed.by.other.bounds");
2989 tree.bounds = List.of(tree.bounds.head);
2990 a.bound = bs.head;
2991 }
2992 } else {
2993 // if first bound was a class or interface, accept only interfaces
2994 // as further bounds.
2995 for (JCExpression bound : tree.bounds.tail) {
2996 bs = bs.tail;
2997 Type i = checkBase(bs.head, bound, env, false, true, false);
2998 if (i.isErroneous())
2999 a.bound = i;
3000 else if (i.tag == CLASS)
3001 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
3002 }
3003 }
3004 }
3005 bs = types.getBounds(a);
3006
3007 // in case of multiple bounds ...
3008 if (bs.length() > 1) {
3009 // ... the variable's bound is a class type flagged COMPOUND
3010 // (see comment for TypeVar.bound).
3011 // In this case, generate a class tree that represents the
3012 // bound class, ...
3013 JCExpression extending;
3014 List<JCExpression> implementing;
3015 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
3016 extending = tree.bounds.head;
3017 implementing = tree.bounds.tail;
3018 } else {
3019 extending = null;
3020 implementing = tree.bounds;
3021 }
3022 JCClassDecl cd = make.at(tree.pos).ClassDef(
3023 make.Modifiers(PUBLIC | ABSTRACT),
3024 tree.name, List.<JCTypeParameter>nil(),
3025 extending, implementing, List.<JCTree>nil());
3026
3027 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
3028 Assert.check((c.flags() & COMPOUND) != 0);
3029 cd.sym = c;
3030 c.sourcefile = env.toplevel.sourcefile;
3031
3032 // ... and attribute the bound class
3033 c.flags_field |= UNATTRIBUTED;
3034 Env<AttrContext> cenv = enter.classEnv(cd, env);
3035 enter.typeEnvs.put(c, cenv);
3036 }
3037 }
3038
3039
3040 public void visitWildcard(JCWildcard tree) {
3041 //- System.err.println("visitWildcard("+tree+");");//DEBUG
3042 Type type = (tree.kind.kind == BoundKind.UNBOUND)
3043 ? syms.objectType
3044 : attribType(tree.inner, env);
3045 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
3046 tree.kind.kind,
3047 syms.boundClass),
3048 TYP, pkind, pt);
3049 }
3050
3051 public void visitAnnotation(JCAnnotation tree) {
3052 log.error(tree.pos(), "annotation.not.valid.for.type", pt);
3053 result = tree.type = syms.errType;
3054 }
3055
3056 public void visitErroneous(JCErroneous tree) {
3057 if (tree.errs != null)
3058 for (JCTree err : tree.errs)
3059 attribTree(err, env, ERR, pt);
3060 result = tree.type = syms.errType;
3061 }
3062
3063 /** Default visitor method for all other trees.
3064 */
3065 public void visitTree(JCTree tree) {
3066 throw new AssertionError();
3067 }
3068
3069 /**
3070 * Attribute an env for either a top level tree or class declaration.
3071 */
3072 public void attrib(Env<AttrContext> env) {
3073 if (env.tree.getTag() == JCTree.Tag.TOPLEVEL)
3074 attribTopLevel(env);
3075 else
3076 attribClass(env.tree.pos(), env.enclClass.sym);
3077 }
3078
3079 /**
3080 * Attribute a top level tree. These trees are encountered when the
3081 * package declaration has annotations.
3082 */
3083 public void attribTopLevel(Env<AttrContext> env) {
3084 JCCompilationUnit toplevel = env.toplevel;
3085 try {
3086 annotate.flush();
3087 chk.validateAnnotations(toplevel.packageAnnotations, toplevel.packge);
3088 } catch (CompletionFailure ex) {
3089 chk.completionError(toplevel.pos(), ex);
3090 }
3091 }
3092
3093 /** Main method: attribute class definition associated with given class symbol.
3094 * reporting completion failures at the given position.
3095 * @param pos The source position at which completion errors are to be
3096 * reported.
3097 * @param c The class symbol whose definition will be attributed.
3098 */
3099 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
3100 try {
3101 annotate.flush();
3102 attribClass(c);
3103 } catch (CompletionFailure ex) {
3104 chk.completionError(pos, ex);
3105 }
3106 }
3107
3108 /** Attribute class definition associated with given class symbol.
3109 * @param c The class symbol whose definition will be attributed.
3110 */
3111 void attribClass(ClassSymbol c) throws CompletionFailure {
3112 if (c.type.tag == ERROR) return;
3113
3114 // Check for cycles in the inheritance graph, which can arise from
3115 // ill-formed class files.
3116 chk.checkNonCyclic(null, c.type);
3117
3118 Type st = types.supertype(c.type);
3119 if ((c.flags_field & Flags.COMPOUND) == 0) {
3120 // First, attribute superclass.
3121 if (st.tag == CLASS)
3122 attribClass((ClassSymbol)st.tsym);
3123
3124 // Next attribute owner, if it is a class.
3125 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
3126 attribClass((ClassSymbol)c.owner);
3127 }
3128
3129 // The previous operations might have attributed the current class
3130 // if there was a cycle. So we test first whether the class is still
3131 // UNATTRIBUTED.
3132 if ((c.flags_field & UNATTRIBUTED) != 0) {
3133 c.flags_field &= ~UNATTRIBUTED;
3134
3135 // Get environment current at the point of class definition.
3136 Env<AttrContext> env = enter.typeEnvs.get(c);
3137
3138 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
3139 // because the annotations were not available at the time the env was created. Therefore,
3140 // we look up the environment chain for the first enclosing environment for which the
3141 // lint value is set. Typically, this is the parent env, but might be further if there
3142 // are any envs created as a result of TypeParameter nodes.
3143 Env<AttrContext> lintEnv = env;
3144 while (lintEnv.info.lint == null)
3145 lintEnv = lintEnv.next;
3146
3147 // Having found the enclosing lint value, we can initialize the lint value for this class
3148 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
3149
3150 Lint prevLint = chk.setLint(env.info.lint);
3151 JavaFileObject prev = log.useSource(c.sourcefile);
3152
3153 try {
3154 // java.lang.Enum may not be subclassed by a non-enum
3155 if (st.tsym == syms.enumSym &&
3156 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
3157 log.error(env.tree.pos(), "enum.no.subclassing");
3158
3159 // Enums may not be extended by source-level classes
3160 if (st.tsym != null &&
3161 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
3162 ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
3163 !target.compilerBootstrap(c)) {
3164 log.error(env.tree.pos(), "enum.types.not.extensible");
3165 }
3166 attribClassBody(env, c);
3167
3168 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
3169 } finally {
3170 log.useSource(prev);
3171 chk.setLint(prevLint);
3172 }
3173
3174 }
3175 }
3176
3177 public void visitImport(JCImport tree) {
3178 // nothing to do
3179 }
3180
3181 /** Finish the attribution of a class. */
3182 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
3183 JCClassDecl tree = (JCClassDecl)env.tree;
3184 Assert.check(c == tree.sym);
3185
3186 // Validate annotations
3187 chk.validateAnnotations(tree.mods.annotations, c);
3188
3189 // Validate type parameters, supertype and interfaces.
3190 attribBounds(tree.typarams);
3191 if (!c.isAnonymous()) {
3192 //already checked if anonymous
3193 chk.validate(tree.typarams, env);
3194 chk.validate(tree.extending, env);
3195 chk.validate(tree.implementing, env);
3196 }
3197
3198 // If this is a non-abstract class, check that it has no abstract
3199 // methods or unimplemented methods of an implemented interface.
3200 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
3201 if (!relax)
3202 chk.checkAllDefined(tree.pos(), c);
3203 }
3204
3205 if ((c.flags() & ANNOTATION) != 0) {
3206 if (tree.implementing.nonEmpty())
3207 log.error(tree.implementing.head.pos(),
3208 "cant.extend.intf.annotation");
3209 if (tree.typarams.nonEmpty())
3210 log.error(tree.typarams.head.pos(),
3211 "intf.annotation.cant.have.type.params");
3212 } else {
3213 // Check that all extended classes and interfaces
3214 // are compatible (i.e. no two define methods with same arguments
3215 // yet different return types). (JLS 8.4.6.3)
3216 chk.checkCompatibleSupertypes(tree.pos(), c.type);
3217 }
3218
3219 // Check that class does not import the same parameterized interface
3220 // with two different argument lists.
3221 chk.checkClassBounds(tree.pos(), c.type);
3222
3223 tree.type = c.type;
3224
3225 for (List<JCTypeParameter> l = tree.typarams;
3226 l.nonEmpty(); l = l.tail) {
3227 Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope);
3228 }
3229
3230 // Check that a generic class doesn't extend Throwable
3231 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
3232 log.error(tree.extending.pos(), "generic.throwable");
3233
3234 // Check that all methods which implement some
3235 // method conform to the method they implement.
3236 chk.checkImplementations(tree);
3237
3238 //check that a resource implementing AutoCloseable cannot throw InterruptedException
3239 checkAutoCloseable(tree.pos(), env, c.type);
3240
3241 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3242 // Attribute declaration
3243 attribStat(l.head, env);
3244 // Check that declarations in inner classes are not static (JLS 8.1.2)
3245 // Make an exception for static constants.
3246 if (c.owner.kind != PCK &&
3247 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
3248 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
3249 Symbol sym = null;
3250 if (l.head.getTag() == JCTree.Tag.VARDEF) sym = ((JCVariableDecl) l.head).sym;
3251 if (sym == null ||
3252 sym.kind != VAR ||
3253 ((VarSymbol) sym).getConstValue() == null)
3254 log.error(l.head.pos(), "icls.cant.have.static.decl", c);
3255 }
3256 }
3257
3258 // Check for cycles among non-initial constructors.
3259 chk.checkCyclicConstructors(tree);
3260
3261 // Check for cycles among annotation elements.
3262 chk.checkNonCyclicElements(tree);
3263
3264 // Check for proper use of serialVersionUID
3265 if (env.info.lint.isEnabled(LintCategory.SERIAL) &&
3266 isSerializable(c) &&
3267 (c.flags() & Flags.ENUM) == 0 &&
3268 (c.flags() & ABSTRACT) == 0) {
3269 checkSerialVersionUID(tree, c);
3270 }
3271 }
3272 // where
3273 /** check if a class is a subtype of Serializable, if that is available. */
3274 private boolean isSerializable(ClassSymbol c) {
3275 try {
3276 syms.serializableType.complete();
3277 }
3278 catch (CompletionFailure e) {
3279 return false;
3280 }
3281 return types.isSubtype(c.type, syms.serializableType);
3282 }
3283
3284 /** Check that an appropriate serialVersionUID member is defined. */
3285 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
3286
3287 // check for presence of serialVersionUID
3288 Scope.Entry e = c.members().lookup(names.serialVersionUID);
3289 while (e.scope != null && e.sym.kind != VAR) e = e.next();
3290 if (e.scope == null) {
3291 log.warning(LintCategory.SERIAL,
3292 tree.pos(), "missing.SVUID", c);
3293 return;
3294 }
3295
3296 // check that it is static final
3297 VarSymbol svuid = (VarSymbol)e.sym;
3298 if ((svuid.flags() & (STATIC | FINAL)) !=
3299 (STATIC | FINAL))
3300 log.warning(LintCategory.SERIAL,
3301 TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
3302
3303 // check that it is long
3304 else if (svuid.type.tag != TypeTags.LONG)
3305 log.warning(LintCategory.SERIAL,
3306 TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
3307
3308 // check constant
3309 else if (svuid.getConstValue() == null)
3310 log.warning(LintCategory.SERIAL,
3311 TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
3312 }
3313
3314 private Type capture(Type type) {
3315 return types.capture(type);
3316 }
3317
3318 // <editor-fold desc="post-attribution visitor">
3319
3320 /**
3321 * Handle missing types/symbols in an AST. This routine is useful when
3322 * the compiler has encountered some errors (which might have ended up
3323 * terminating attribution abruptly); if the compiler is used in fail-over
3324 * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
3325 * prevents NPE to be progagated during subsequent compilation steps.
3326 */
3327 public void postAttr(Env<AttrContext> env) {
3328 new PostAttrAnalyzer().scan(env.tree);
3329 }
3330
3331 class PostAttrAnalyzer extends TreeScanner {
3332
3333 private void initTypeIfNeeded(JCTree that) {
3334 if (that.type == null) {
3335 that.type = syms.unknownType;
3336 }
3337 }
3338
3339 @Override
3340 public void scan(JCTree tree) {
3341 if (tree == null) return;
3342 if (tree instanceof JCExpression) {
3343 initTypeIfNeeded(tree);
3344 }
3345 super.scan(tree);
3346 }
3347
3348 @Override
3349 public void visitIdent(JCIdent that) {
3350 if (that.sym == null) {
3351 that.sym = syms.unknownSymbol;
3352 }
3353 }
3354
3355 @Override
3356 public void visitSelect(JCFieldAccess that) {
3357 if (that.sym == null) {
3358 that.sym = syms.unknownSymbol;
3359 }
3360 super.visitSelect(that);
3361 }
3362
3363 @Override
3364 public void visitClassDef(JCClassDecl that) {
3365 initTypeIfNeeded(that);
3366 if (that.sym == null) {
3367 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
3368 }
3369 super.visitClassDef(that);
3370 }
3371
3372 @Override
3373 public void visitMethodDef(JCMethodDecl that) {
3374 initTypeIfNeeded(that);
3375 if (that.sym == null) {
3376 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
3377 }
3378 super.visitMethodDef(that);
3379 }
3380
3381 @Override
3382 public void visitVarDef(JCVariableDecl that) {
3383 initTypeIfNeeded(that);
3384 if (that.sym == null) {
3385 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
3386 that.sym.adr = 0;
3387 }
3388 super.visitVarDef(that);
3389 }
3390
3391 @Override
3392 public void visitNewClass(JCNewClass that) {
3393 if (that.constructor == null) {
3394 that.constructor = new MethodSymbol(0, names.init, syms.unknownType, syms.noSymbol);
3395 }
3396 if (that.constructorType == null) {
3397 that.constructorType = syms.unknownType;
3398 }
3399 super.visitNewClass(that);
3400 }
3401
3402 @Override
3403 public void visitAssignop(JCAssignOp that) {
3404 if (that.operator == null)
3405 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3406 super.visitAssignop(that);
3407 }
3408
3409 @Override
3410 public void visitBinary(JCBinary that) {
3411 if (that.operator == null)
3412 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3413 super.visitBinary(that);
3414 }
3415
3416 @Override
3417 public void visitUnary(JCUnary that) {
3418 if (that.operator == null)
3419 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3420 super.visitUnary(that);
3421 }
3422 }
3423 // </editor-fold>
3424 }