1 /*
2 * Copyright (c) 1999, 2009, 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.Symbol.*;
42 import com.sun.tools.javac.tree.JCTree.*;
43 import com.sun.tools.javac.code.Type.*;
44
45 import com.sun.source.tree.IdentifierTree;
46 import com.sun.source.tree.MemberSelectTree;
47 import com.sun.source.tree.TreeVisitor;
48 import com.sun.source.util.SimpleTreeVisitor;
49
50 import static com.sun.tools.javac.code.Flags.*;
51 import static com.sun.tools.javac.code.Kinds.*;
52 import static com.sun.tools.javac.code.TypeTags.*;
53
54 /** This is the main context-dependent analysis phase in GJC. It
55 * encompasses name resolution, type checking and constant folding as
56 * subtasks. Some subtasks involve auxiliary classes.
57 * @see Check
58 * @see Resolve
59 * @see ConstFold
60 * @see Infer
61 *
62 * <p><b>This is NOT part of any supported API.
63 * If you write code that depends on this, you do so at your own risk.
64 * This code and its internal interfaces are subject to change or
65 * deletion without notice.</b>
66 */
67 public class Attr extends JCTree.Visitor {
68 protected static final Context.Key<Attr> attrKey =
69 new Context.Key<Attr>();
70
71 final Names names;
72 final Log log;
73 final Symtab syms;
74 final Resolve rs;
75 final Infer infer;
76 final Check chk;
77 final MemberEnter memberEnter;
78 final TreeMaker make;
79 final ConstFold cfolder;
80 final Enter enter;
81 final Target target;
82 final Types types;
83 final JCDiagnostic.Factory diags;
84 final Annotate annotate;
85
86 public static Attr instance(Context context) {
87 Attr instance = context.get(attrKey);
88 if (instance == null)
89 instance = new Attr(context);
90 return instance;
91 }
92
93 protected Attr(Context context) {
94 context.put(attrKey, this);
95
96 names = Names.instance(context);
97 log = Log.instance(context);
98 syms = Symtab.instance(context);
99 rs = Resolve.instance(context);
100 chk = Check.instance(context);
101 memberEnter = MemberEnter.instance(context);
102 make = TreeMaker.instance(context);
103 enter = Enter.instance(context);
104 infer = Infer.instance(context);
105 cfolder = ConstFold.instance(context);
106 target = Target.instance(context);
107 types = Types.instance(context);
108 diags = JCDiagnostic.Factory.instance(context);
109 annotate = Annotate.instance(context);
110
111 Options options = Options.instance(context);
112
113 Source source = Source.instance(context);
114 allowGenerics = source.allowGenerics();
115 allowVarargs = source.allowVarargs();
116 allowEnums = source.allowEnums();
117 allowBoxing = source.allowBoxing();
118 allowCovariantReturns = source.allowCovariantReturns();
119 allowAnonOuterThis = source.allowAnonOuterThis();
120 allowStringsInSwitch = source.allowStringsInSwitch();
121 sourceName = source.name;
122 relax = (options.get("-retrofit") != null ||
123 options.get("-relax") != null);
124 useBeforeDeclarationWarning = options.get("useBeforeDeclarationWarning") != null;
125 enableSunApiLintControl = options.get("enableSunApiLintControl") != null;
126 }
127
128 /** Switch: relax some constraints for retrofit mode.
129 */
130 boolean relax;
131
132 /** Switch: support generics?
133 */
134 boolean allowGenerics;
135
136 /** Switch: allow variable-arity methods.
137 */
138 boolean allowVarargs;
139
140 /** Switch: support enums?
141 */
142 boolean allowEnums;
143
144 /** Switch: support boxing and unboxing?
145 */
146 boolean allowBoxing;
147
148 /** Switch: support covariant result types?
149 */
150 boolean allowCovariantReturns;
151
152 /** Switch: allow references to surrounding object from anonymous
153 * objects during constructor call?
154 */
155 boolean allowAnonOuterThis;
156
157 /**
158 * Switch: warn about use of variable before declaration?
159 * RFE: 6425594
160 */
161 boolean useBeforeDeclarationWarning;
162
163 /**
164 * Switch: allow lint infrastructure to control proprietary
165 * API warnings.
166 */
167 boolean enableSunApiLintControl;
168
169 /**
170 * Switch: allow strings in switch?
171 */
172 boolean allowStringsInSwitch;
173
174 /**
175 * Switch: name of source level; used for error reporting.
176 */
177 String sourceName;
178
179 /** Check kind and type of given tree against protokind and prototype.
180 * If check succeeds, store type in tree and return it.
181 * If check fails, store errType in tree and return it.
182 * No checks are performed if the prototype is a method type.
183 * It is not necessary in this case since we know that kind and type
184 * are correct.
185 *
186 * @param tree The tree whose kind and type is checked
187 * @param owntype The computed type of the tree
188 * @param ownkind The computed kind of the tree
189 * @param pkind The expected kind (or: protokind) of the tree
190 * @param pt The expected type (or: prototype) of the tree
191 */
192 Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
193 if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
194 if ((ownkind & ~pkind) == 0) {
195 owntype = chk.checkType(tree.pos(), owntype, pt, errKey);
196 } else {
197 log.error(tree.pos(), "unexpected.type",
198 kindNames(pkind),
199 kindName(ownkind));
200 owntype = types.createErrorType(owntype);
201 }
202 }
203 tree.type = owntype;
204 return owntype;
205 }
206
207 /** Is given blank final variable assignable, i.e. in a scope where it
208 * may be assigned to even though it is final?
209 * @param v The blank final variable.
210 * @param env The current environment.
211 */
212 boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
213 Symbol owner = env.info.scope.owner;
214 // owner refers to the innermost variable, method or
215 // initializer block declaration at this point.
216 return
217 v.owner == owner
218 ||
219 ((owner.name == names.init || // i.e. we are in a constructor
220 owner.kind == VAR || // i.e. we are in a variable initializer
221 (owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
222 &&
223 v.owner == owner.owner
224 &&
225 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
226 }
227
228 /** Check that variable can be assigned to.
229 * @param pos The current source code position.
230 * @param v The assigned varaible
231 * @param base If the variable is referred to in a Select, the part
232 * to the left of the `.', null otherwise.
233 * @param env The current environment.
234 */
235 void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
236 if ((v.flags() & FINAL) != 0 &&
237 ((v.flags() & HASINIT) != 0
238 ||
239 !((base == null ||
240 (base.getTag() == JCTree.IDENT && TreeInfo.name(base) == names._this)) &&
241 isAssignableAsBlankFinal(v, env)))) {
242 if (v.isResourceVariable()) { //ARM resource
243 log.error(pos, "arm.resource.may.not.be.assigned", v);
244 } else {
245 log.error(pos, "cant.assign.val.to.final.var", v);
246 }
247 }
248 }
249
250 /** Does tree represent a static reference to an identifier?
251 * It is assumed that tree is either a SELECT or an IDENT.
252 * We have to weed out selects from non-type names here.
253 * @param tree The candidate tree.
254 */
255 boolean isStaticReference(JCTree tree) {
256 if (tree.getTag() == JCTree.SELECT) {
257 Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
258 if (lsym == null || lsym.kind != TYP) {
259 return false;
260 }
261 }
262 return true;
263 }
264
265 /** Is this symbol a type?
266 */
267 static boolean isType(Symbol sym) {
268 return sym != null && sym.kind == TYP;
269 }
270
271 /** The current `this' symbol.
272 * @param env The current environment.
273 */
274 Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
275 return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
276 }
277
278 /** Attribute a parsed identifier.
279 * @param tree Parsed identifier name
280 * @param topLevel The toplevel to use
281 */
282 public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
283 Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
284 localEnv.enclClass = make.ClassDef(make.Modifiers(0),
285 syms.errSymbol.name,
286 null, null, null, null);
287 localEnv.enclClass.sym = syms.errSymbol;
288 return tree.accept(identAttributer, localEnv);
289 }
290 // where
291 private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
292 private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
293 @Override
294 public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
295 Symbol site = visit(node.getExpression(), env);
296 if (site.kind == ERR)
297 return site;
298 Name name = (Name)node.getIdentifier();
299 if (site.kind == PCK) {
300 env.toplevel.packge = (PackageSymbol)site;
301 return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
302 } else {
303 env.enclClass.sym = (ClassSymbol)site;
304 return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
305 }
306 }
307
308 @Override
309 public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
310 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
311 }
312 }
313
314 public Type coerce(Type etype, Type ttype) {
315 return cfolder.coerce(etype, ttype);
316 }
317
318 public Type attribType(JCTree node, TypeSymbol sym) {
319 Env<AttrContext> env = enter.typeEnvs.get(sym);
320 Env<AttrContext> localEnv = env.dup(node, env.info.dup());
321 return attribTree(node, localEnv, Kinds.TYP, Type.noType);
322 }
323
324 public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
325 breakTree = tree;
326 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
327 try {
328 attribExpr(expr, env);
329 } catch (BreakAttr b) {
330 return b.env;
331 } finally {
332 breakTree = null;
333 log.useSource(prev);
334 }
335 return env;
336 }
337
338 public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
339 breakTree = tree;
340 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
341 try {
342 attribStat(stmt, env);
343 } catch (BreakAttr b) {
344 return b.env;
345 } finally {
346 breakTree = null;
347 log.useSource(prev);
348 }
349 return env;
350 }
351
352 private JCTree breakTree = null;
353
354 private static class BreakAttr extends RuntimeException {
355 static final long serialVersionUID = -6924771130405446405L;
356 private Env<AttrContext> env;
357 private BreakAttr(Env<AttrContext> env) {
358 this.env = env;
359 }
360 }
361
362
363 /* ************************************************************************
364 * Visitor methods
365 *************************************************************************/
366
367 /** Visitor argument: the current environment.
368 */
369 Env<AttrContext> env;
370
371 /** Visitor argument: the currently expected proto-kind.
372 */
373 int pkind;
374
375 /** Visitor argument: the currently expected proto-type.
376 */
377 Type pt;
378
379 /** Visitor argument: the error key to be generated when a type error occurs
380 */
381 String errKey;
382
383 /** Visitor result: the computed type.
384 */
385 Type result;
386
387 /** Visitor method: attribute a tree, catching any completion failure
388 * exceptions. Return the tree's type.
389 *
390 * @param tree The tree to be visited.
391 * @param env The environment visitor argument.
392 * @param pkind The protokind visitor argument.
393 * @param pt The prototype visitor argument.
394 */
395 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) {
396 return attribTree(tree, env, pkind, pt, "incompatible.types");
397 }
398
399 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt, String errKey) {
400 Env<AttrContext> prevEnv = this.env;
401 int prevPkind = this.pkind;
402 Type prevPt = this.pt;
403 String prevErrKey = this.errKey;
404 try {
405 this.env = env;
406 this.pkind = pkind;
407 this.pt = pt;
408 this.errKey = errKey;
409 tree.accept(this);
410 if (tree == breakTree)
411 throw new BreakAttr(env);
412 return result;
413 } catch (CompletionFailure ex) {
414 tree.type = syms.errType;
415 return chk.completionError(tree.pos(), ex);
416 } finally {
417 this.env = prevEnv;
418 this.pkind = prevPkind;
419 this.pt = prevPt;
420 this.errKey = prevErrKey;
421 }
422 }
423
424 /** Derived visitor method: attribute an expression tree.
425 */
426 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
427 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
428 }
429
430 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt, String key) {
431 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType, key);
432 }
433
434 /** Derived visitor method: attribute an expression tree with
435 * no constraints on the computed type.
436 */
437 Type attribExpr(JCTree tree, Env<AttrContext> env) {
438 return attribTree(tree, env, VAL, Type.noType);
439 }
440
441 /** Derived visitor method: attribute a type tree.
442 */
443 Type attribType(JCTree tree, Env<AttrContext> env) {
444 Type result = attribType(tree, env, Type.noType);
445 return result;
446 }
447
448 /** Derived visitor method: attribute a type tree.
449 */
450 Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
451 Type result = attribTree(tree, env, TYP, pt);
452 return result;
453 }
454
455 /** Derived visitor method: attribute a statement or definition tree.
456 */
457 public Type attribStat(JCTree tree, Env<AttrContext> env) {
458 return attribTree(tree, env, NIL, Type.noType);
459 }
460
461 /** Attribute a list of expressions, returning a list of types.
462 */
463 List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
464 ListBuffer<Type> ts = new ListBuffer<Type>();
465 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
466 ts.append(attribExpr(l.head, env, pt));
467 return ts.toList();
468 }
469
470 /** Attribute a list of statements, returning nothing.
471 */
472 <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
473 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
474 attribStat(l.head, env);
475 }
476
477 /** Attribute the arguments in a method call, returning a list of types.
478 */
479 List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
480 ListBuffer<Type> argtypes = new ListBuffer<Type>();
481 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
482 argtypes.append(chk.checkNonVoid(
483 l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly))));
484 return argtypes.toList();
485 }
486
487 /** Attribute a type argument list, returning a list of types.
488 * Caller is responsible for calling checkRefTypes.
489 */
490 List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
491 ListBuffer<Type> argtypes = new ListBuffer<Type>();
492 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
493 argtypes.append(attribType(l.head, env));
494 return argtypes.toList();
495 }
496
497 /** Attribute a type argument list, returning a list of types.
498 * Check that all the types are references.
499 */
500 List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
501 List<Type> types = attribAnyTypes(trees, env);
502 return chk.checkRefTypes(trees, types);
503 }
504
505 /**
506 * Attribute type variables (of generic classes or methods).
507 * Compound types are attributed later in attribBounds.
508 * @param typarams the type variables to enter
509 * @param env the current environment
510 */
511 void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
512 for (JCTypeParameter tvar : typarams) {
513 TypeVar a = (TypeVar)tvar.type;
514 a.tsym.flags_field |= UNATTRIBUTED;
515 a.bound = Type.noType;
516 if (!tvar.bounds.isEmpty()) {
517 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
518 for (JCExpression bound : tvar.bounds.tail)
519 bounds = bounds.prepend(attribType(bound, env));
520 types.setBounds(a, bounds.reverse());
521 } else {
522 // if no bounds are given, assume a single bound of
523 // java.lang.Object.
524 types.setBounds(a, List.of(syms.objectType));
525 }
526 a.tsym.flags_field &= ~UNATTRIBUTED;
527 }
528 for (JCTypeParameter tvar : typarams)
529 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
530 attribStats(typarams, env);
531 }
532
533 void attribBounds(List<JCTypeParameter> typarams) {
534 for (JCTypeParameter typaram : typarams) {
535 Type bound = typaram.type.getUpperBound();
536 if (bound != null && bound.tsym instanceof ClassSymbol) {
537 ClassSymbol c = (ClassSymbol)bound.tsym;
538 if ((c.flags_field & COMPOUND) != 0) {
539 assert (c.flags_field & UNATTRIBUTED) != 0 : c;
540 attribClass(typaram.pos(), c);
541 }
542 }
543 }
544 }
545
546 /**
547 * Attribute the type references in a list of annotations.
548 */
549 void attribAnnotationTypes(List<JCAnnotation> annotations,
550 Env<AttrContext> env) {
551 for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
552 JCAnnotation a = al.head;
553 attribType(a.annotationType, env);
554 }
555 }
556
557 /** Attribute type reference in an `extends' or `implements' clause.
558 * Supertypes of anonymous inner classes are usually already attributed.
559 *
560 * @param tree The tree making up the type reference.
561 * @param env The environment current at the reference.
562 * @param classExpected true if only a class is expected here.
563 * @param interfaceExpected true if only an interface is expected here.
564 */
565 Type attribBase(JCTree tree,
566 Env<AttrContext> env,
567 boolean classExpected,
568 boolean interfaceExpected,
569 boolean checkExtensible) {
570 Type t = tree.type != null ?
571 tree.type :
572 attribType(tree, env);
573 return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
574 }
575 Type checkBase(Type t,
576 JCTree tree,
577 Env<AttrContext> env,
578 boolean classExpected,
579 boolean interfaceExpected,
580 boolean checkExtensible) {
581 if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
582 // check that type variable is already visible
583 if (t.getUpperBound() == null) {
584 log.error(tree.pos(), "illegal.forward.ref");
585 return types.createErrorType(t);
586 }
587 } else {
588 t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
589 }
590 if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
591 log.error(tree.pos(), "intf.expected.here");
592 // return errType is necessary since otherwise there might
593 // be undetected cycles which cause attribution to loop
594 return types.createErrorType(t);
595 } else if (checkExtensible &&
596 classExpected &&
597 (t.tsym.flags() & INTERFACE) != 0) {
598 log.error(tree.pos(), "no.intf.expected.here");
599 return types.createErrorType(t);
600 }
601 if (checkExtensible &&
602 ((t.tsym.flags() & FINAL) != 0)) {
603 log.error(tree.pos(),
604 "cant.inherit.from.final", t.tsym);
605 }
606 chk.checkNonCyclic(tree.pos(), t);
607 return t;
608 }
609
610 public void visitClassDef(JCClassDecl tree) {
611 // Local classes have not been entered yet, so we need to do it now:
612 if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
613 enter.classEnter(tree, env);
614
615 ClassSymbol c = tree.sym;
616 if (c == null) {
617 // exit in case something drastic went wrong during enter.
618 result = null;
619 } else {
620 // make sure class has been completed:
621 c.complete();
622
623 // If this class appears as an anonymous class
624 // in a superclass constructor call where
625 // no explicit outer instance is given,
626 // disable implicit outer instance from being passed.
627 // (This would be an illegal access to "this before super").
628 if (env.info.isSelfCall &&
629 env.tree.getTag() == JCTree.NEWCLASS &&
630 ((JCNewClass) env.tree).encl == null)
631 {
632 c.flags_field |= NOOUTERTHIS;
633 }
634 attribClass(tree.pos(), c);
635 result = tree.type = c.type;
636 }
637 }
638
639 public void visitMethodDef(JCMethodDecl tree) {
640 MethodSymbol m = tree.sym;
641
642 Lint lint = env.info.lint.augment(m.attributes_field, m.flags());
643 Lint prevLint = chk.setLint(lint);
644 try {
645 chk.checkDeprecatedAnnotation(tree.pos(), m);
646
647 attribBounds(tree.typarams);
648
649 // If we override any other methods, check that we do so properly.
650 // JLS ???
651 chk.checkOverride(tree, m);
652
653 // Create a new environment with local scope
654 // for attributing the method.
655 Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
656
657 localEnv.info.lint = lint;
658
659 // Enter all type parameters into the local method scope.
660 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
661 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
662
663 ClassSymbol owner = env.enclClass.sym;
664 if ((owner.flags() & ANNOTATION) != 0 &&
665 tree.params.nonEmpty())
666 log.error(tree.params.head.pos(),
667 "intf.annotation.members.cant.have.params");
668
669 // Attribute all value parameters.
670 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
671 attribStat(l.head, localEnv);
672 }
673
674 chk.checkVarargMethodDecl(tree);
675
676 // Check that type parameters are well-formed.
677 chk.validate(tree.typarams, localEnv);
678 if ((owner.flags() & ANNOTATION) != 0 &&
679 tree.typarams.nonEmpty())
680 log.error(tree.typarams.head.pos(),
681 "intf.annotation.members.cant.have.type.params");
682
683 // Check that result type is well-formed.
684 chk.validate(tree.restype, localEnv);
685 if ((owner.flags() & ANNOTATION) != 0)
686 chk.validateAnnotationType(tree.restype);
687
688 if ((owner.flags() & ANNOTATION) != 0)
689 chk.validateAnnotationMethod(tree.pos(), m);
690
691 // Check that all exceptions mentioned in the throws clause extend
692 // java.lang.Throwable.
693 if ((owner.flags() & ANNOTATION) != 0 && tree.thrown.nonEmpty())
694 log.error(tree.thrown.head.pos(),
695 "throws.not.allowed.in.intf.annotation");
696 for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
697 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
698
699 if (tree.body == null) {
700 // Empty bodies are only allowed for
701 // abstract, native, or interface methods, or for methods
702 // in a retrofit signature class.
703 if ((owner.flags() & INTERFACE) == 0 &&
704 (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 &&
705 !relax)
706 log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
707 if (tree.defaultValue != null) {
708 if ((owner.flags() & ANNOTATION) == 0)
709 log.error(tree.pos(),
710 "default.allowed.in.intf.annotation.member");
711 }
712 } else if ((owner.flags() & INTERFACE) != 0) {
713 log.error(tree.body.pos(), "intf.meth.cant.have.body");
714 } else if ((tree.mods.flags & ABSTRACT) != 0) {
715 log.error(tree.pos(), "abstract.meth.cant.have.body");
716 } else if ((tree.mods.flags & NATIVE) != 0) {
717 log.error(tree.pos(), "native.meth.cant.have.body");
718 } else {
719 // Add an implicit super() call unless an explicit call to
720 // super(...) or this(...) is given
721 // or we are compiling class java.lang.Object.
722 if (tree.name == names.init && owner.type != syms.objectType) {
723 JCBlock body = tree.body;
724 if (body.stats.isEmpty() ||
725 !TreeInfo.isSelfCall(body.stats.head)) {
726 body.stats = body.stats.
727 prepend(memberEnter.SuperCall(make.at(body.pos),
728 List.<Type>nil(),
729 List.<JCVariableDecl>nil(),
730 false));
731 } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
732 (tree.mods.flags & GENERATEDCONSTR) == 0 &&
733 TreeInfo.isSuperCall(body.stats.head)) {
734 // enum constructors are not allowed to call super
735 // directly, so make sure there aren't any super calls
736 // in enum constructors, except in the compiler
737 // generated one.
738 log.error(tree.body.stats.head.pos(),
739 "call.to.super.not.allowed.in.enum.ctor",
740 env.enclClass.sym);
741 }
742 }
743
744 // Attribute method body.
745 attribStat(tree.body, localEnv);
746 }
747 localEnv.info.scope.leave();
748 result = tree.type = m.type;
749 chk.validateAnnotations(tree.mods.annotations, m);
750 }
751 finally {
752 chk.setLint(prevLint);
753 }
754 }
755
756 public void visitVarDef(JCVariableDecl tree) {
757 // Local variables have not been entered yet, so we need to do it now:
758 if (env.info.scope.owner.kind == MTH) {
759 if (tree.sym != null) {
760 // parameters have already been entered
761 env.info.scope.enter(tree.sym);
762 } else {
763 memberEnter.memberEnter(tree, env);
764 annotate.flush();
765 }
766 }
767
768 VarSymbol v = tree.sym;
769 Lint lint = env.info.lint.augment(v.attributes_field, v.flags());
770 Lint prevLint = chk.setLint(lint);
771
772 // Check that the variable's declared type is well-formed.
773 chk.validate(tree.vartype, env);
774
775 try {
776 chk.checkDeprecatedAnnotation(tree.pos(), v);
777
778 if (tree.init != null) {
779 if ((v.flags_field & FINAL) != 0 && tree.init.getTag() != JCTree.NEWCLASS) {
780 // In this case, `v' is final. Ensure that it's initializer is
781 // evaluated.
782 v.getConstValue(); // ensure initializer is evaluated
783 } else {
784 // Attribute initializer in a new environment
785 // with the declared variable as owner.
786 // Check that initializer conforms to variable's declared type.
787 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
788 initEnv.info.lint = lint;
789 // In order to catch self-references, we set the variable's
790 // declaration position to maximal possible value, effectively
791 // marking the variable as undefined.
792 initEnv.info.enclVar = v;
793 attribExpr(tree.init, initEnv, v.type);
794 }
795 }
796 result = tree.type = v.type;
797 chk.validateAnnotations(tree.mods.annotations, v);
798 }
799 finally {
800 chk.setLint(prevLint);
801 }
802 }
803
804 public void visitSkip(JCSkip tree) {
805 result = null;
806 }
807
808 public void visitBlock(JCBlock tree) {
809 if (env.info.scope.owner.kind == TYP) {
810 // Block is a static or instance initializer;
811 // let the owner of the environment be a freshly
812 // created BLOCK-method.
813 Env<AttrContext> localEnv =
814 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
815 localEnv.info.scope.owner =
816 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
817 env.info.scope.owner);
818 if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
819 attribStats(tree.stats, localEnv);
820 } else {
821 // Create a new local environment with a local scope.
822 Env<AttrContext> localEnv =
823 env.dup(tree, env.info.dup(env.info.scope.dup()));
824 attribStats(tree.stats, localEnv);
825 localEnv.info.scope.leave();
826 }
827 result = null;
828 }
829
830 public void visitDoLoop(JCDoWhileLoop tree) {
831 attribStat(tree.body, env.dup(tree));
832 attribExpr(tree.cond, env, syms.booleanType);
833 result = null;
834 }
835
836 public void visitWhileLoop(JCWhileLoop tree) {
837 attribExpr(tree.cond, env, syms.booleanType);
838 attribStat(tree.body, env.dup(tree));
839 result = null;
840 }
841
842 public void visitForLoop(JCForLoop tree) {
843 Env<AttrContext> loopEnv =
844 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
845 attribStats(tree.init, loopEnv);
846 if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
847 loopEnv.tree = tree; // before, we were not in loop!
848 attribStats(tree.step, loopEnv);
849 attribStat(tree.body, loopEnv);
850 loopEnv.info.scope.leave();
851 result = null;
852 }
853
854 public void visitForeachLoop(JCEnhancedForLoop tree) {
855 Env<AttrContext> loopEnv =
856 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
857 attribStat(tree.var, loopEnv);
858 Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
859 chk.checkNonVoid(tree.pos(), exprType);
860 Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
861 if (elemtype == null) {
862 // or perhaps expr implements Iterable<T>?
863 Type base = types.asSuper(exprType, syms.iterableType.tsym);
864 if (base == null) {
865 log.error(tree.expr.pos(), "foreach.not.applicable.to.type");
866 elemtype = types.createErrorType(exprType);
867 } else {
868 List<Type> iterableParams = base.allparams();
869 elemtype = iterableParams.isEmpty()
870 ? syms.objectType
871 : types.upperBound(iterableParams.head);
872 }
873 }
874 chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
875 loopEnv.tree = tree; // before, we were not in loop!
876 attribStat(tree.body, loopEnv);
877 loopEnv.info.scope.leave();
878 result = null;
879 }
880
881 public void visitLabelled(JCLabeledStatement tree) {
882 // Check that label is not used in an enclosing statement
883 Env<AttrContext> env1 = env;
884 while (env1 != null && env1.tree.getTag() != JCTree.CLASSDEF) {
885 if (env1.tree.getTag() == JCTree.LABELLED &&
886 ((JCLabeledStatement) env1.tree).label == tree.label) {
887 log.error(tree.pos(), "label.already.in.use",
888 tree.label);
889 break;
890 }
891 env1 = env1.next;
892 }
893
894 attribStat(tree.body, env.dup(tree));
895 result = null;
896 }
897
898 public void visitSwitch(JCSwitch tree) {
899 Type seltype = attribExpr(tree.selector, env);
900
901 Env<AttrContext> switchEnv =
902 env.dup(tree, env.info.dup(env.info.scope.dup()));
903
904 boolean enumSwitch =
905 allowEnums &&
906 (seltype.tsym.flags() & Flags.ENUM) != 0;
907 boolean stringSwitch = false;
908 if (types.isSameType(seltype, syms.stringType)) {
909 if (allowStringsInSwitch) {
910 stringSwitch = true;
911 } else {
912 log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName);
913 }
914 }
915 if (!enumSwitch && !stringSwitch)
916 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
917
918 // Attribute all cases and
919 // check that there are no duplicate case labels or default clauses.
920 Set<Object> labels = new HashSet<Object>(); // The set of case labels.
921 boolean hasDefault = false; // Is there a default label?
922 for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
923 JCCase c = l.head;
924 Env<AttrContext> caseEnv =
925 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
926 if (c.pat != null) {
927 if (enumSwitch) {
928 Symbol sym = enumConstant(c.pat, seltype);
929 if (sym == null) {
930 log.error(c.pat.pos(), "enum.const.req");
931 } else if (!labels.add(sym)) {
932 log.error(c.pos(), "duplicate.case.label");
933 }
934 } else {
935 Type pattype = attribExpr(c.pat, switchEnv, seltype);
936 if (pattype.tag != ERROR) {
937 if (pattype.constValue() == null) {
938 log.error(c.pat.pos(),
939 (stringSwitch ? "string.const.req" : "const.expr.req"));
940 } else if (labels.contains(pattype.constValue())) {
941 log.error(c.pos(), "duplicate.case.label");
942 } else {
943 labels.add(pattype.constValue());
944 }
945 }
946 }
947 } else if (hasDefault) {
948 log.error(c.pos(), "duplicate.default.label");
949 } else {
950 hasDefault = true;
951 }
952 attribStats(c.stats, caseEnv);
953 caseEnv.info.scope.leave();
954 addVars(c.stats, switchEnv.info.scope);
955 }
956
957 switchEnv.info.scope.leave();
958 result = null;
959 }
960 // where
961 /** Add any variables defined in stats to the switch scope. */
962 private static void addVars(List<JCStatement> stats, Scope switchScope) {
963 for (;stats.nonEmpty(); stats = stats.tail) {
964 JCTree stat = stats.head;
965 if (stat.getTag() == JCTree.VARDEF)
966 switchScope.enter(((JCVariableDecl) stat).sym);
967 }
968 }
969 // where
970 /** Return the selected enumeration constant symbol, or null. */
971 private Symbol enumConstant(JCTree tree, Type enumType) {
972 if (tree.getTag() != JCTree.IDENT) {
973 log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
974 return syms.errSymbol;
975 }
976 JCIdent ident = (JCIdent)tree;
977 Name name = ident.name;
978 for (Scope.Entry e = enumType.tsym.members().lookup(name);
979 e.scope != null; e = e.next()) {
980 if (e.sym.kind == VAR) {
981 Symbol s = ident.sym = e.sym;
982 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
983 ident.type = s.type;
984 return ((s.flags_field & Flags.ENUM) == 0)
985 ? null : s;
986 }
987 }
988 return null;
989 }
990
991 public void visitSynchronized(JCSynchronized tree) {
992 chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
993 attribStat(tree.body, env);
994 result = null;
995 }
996
997 public void visitTry(JCTry tree) {
998 // Create a new local environment with a local
999 Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1000 // Create a nested environment for attributing the try block
1001 Env<AttrContext> tryEnv = env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup()));
1002 // Attribute resource declarations
1003 for (JCTree resource : tree.resources) {
1004 if (resource.getTag() == JCTree.VARDEF) {
1005 attribStat(resource, tryEnv);
1006 chk.checkType(resource, resource.type, syms.autoCloseableType, "arm.not.applicable.to.type");
1007 VarSymbol var = (VarSymbol)TreeInfo.symbolFor(resource);
1008 var.setData(ElementKind.RESOURCE_VARIABLE);
1009 } else {
1010 attribExpr(resource, tryEnv, syms.autoCloseableType, "arm.not.applicable.to.type");
1011 }
1012 }
1013 // Attribute body
1014 attribStat(tree.body, tryEnv);
1015 tryEnv.info.scope.leave();
1016
1017 // Attribute catch clauses
1018 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
1019 JCCatch c = l.head;
1020 Env<AttrContext> catchEnv =
1021 localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
1022 Type ctype = attribStat(c.param, catchEnv);
1023 if (TreeInfo.isMultiCatch(c)) {
1024 //check that multi-catch parameter is marked as final
1025 if ((c.param.sym.flags() & FINAL) == 0) {
1026 log.error(c.param.pos(), "multicatch.param.must.be.final", c.param.sym);
1027 }
1028 c.param.sym.flags_field = c.param.sym.flags() | DISJOINT;
1029 }
1030 if (c.param.type.tsym.kind == Kinds.VAR) {
1031 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
1032 }
1033 chk.checkType(c.param.vartype.pos(),
1034 chk.checkClassType(c.param.vartype.pos(), ctype),
1035 syms.throwableType);
1036 attribStat(c.body, catchEnv);
1037 catchEnv.info.scope.leave();
1038 }
1039
1040 // Attribute finalizer
1041 if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
1042
1043 localEnv.info.scope.leave();
1044 result = null;
1045 }
1046
1047 public void visitConditional(JCConditional tree) {
1048 attribExpr(tree.cond, env, syms.booleanType);
1049 attribExpr(tree.truepart, env);
1050 attribExpr(tree.falsepart, env);
1051 result = check(tree,
1052 capture(condType(tree.pos(), tree.cond.type,
1053 tree.truepart.type, tree.falsepart.type)),
1054 VAL, pkind, pt);
1055 }
1056 //where
1057 /** Compute the type of a conditional expression, after
1058 * checking that it exists. See Spec 15.25.
1059 *
1060 * @param pos The source position to be used for
1061 * error diagnostics.
1062 * @param condtype The type of the expression's condition.
1063 * @param thentype The type of the expression's then-part.
1064 * @param elsetype The type of the expression's else-part.
1065 */
1066 private Type condType(DiagnosticPosition pos,
1067 Type condtype,
1068 Type thentype,
1069 Type elsetype) {
1070 Type ctype = condType1(pos, condtype, thentype, elsetype);
1071
1072 // If condition and both arms are numeric constants,
1073 // evaluate at compile-time.
1074 return ((condtype.constValue() != null) &&
1075 (thentype.constValue() != null) &&
1076 (elsetype.constValue() != null))
1077 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
1078 : ctype;
1079 }
1080 /** Compute the type of a conditional expression, after
1081 * checking that it exists. Does not take into
1082 * account the special case where condition and both arms
1083 * are constants.
1084 *
1085 * @param pos The source position to be used for error
1086 * diagnostics.
1087 * @param condtype The type of the expression's condition.
1088 * @param thentype The type of the expression's then-part.
1089 * @param elsetype The type of the expression's else-part.
1090 */
1091 private Type condType1(DiagnosticPosition pos, Type condtype,
1092 Type thentype, Type elsetype) {
1093 // If same type, that is the result
1094 if (types.isSameType(thentype, elsetype))
1095 return thentype.baseType();
1096
1097 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1098 ? thentype : types.unboxedType(thentype);
1099 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1100 ? elsetype : types.unboxedType(elsetype);
1101
1102 // Otherwise, if both arms can be converted to a numeric
1103 // type, return the least numeric type that fits both arms
1104 // (i.e. return larger of the two, or return int if one
1105 // arm is short, the other is char).
1106 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1107 // If one arm has an integer subrange type (i.e., byte,
1108 // short, or char), and the other is an integer constant
1109 // that fits into the subrange, return the subrange type.
1110 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1111 types.isAssignable(elseUnboxed, thenUnboxed))
1112 return thenUnboxed.baseType();
1113 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1114 types.isAssignable(thenUnboxed, elseUnboxed))
1115 return elseUnboxed.baseType();
1116
1117 for (int i = BYTE; i < VOID; i++) {
1118 Type candidate = syms.typeOfTag[i];
1119 if (types.isSubtype(thenUnboxed, candidate) &&
1120 types.isSubtype(elseUnboxed, candidate))
1121 return candidate;
1122 }
1123 }
1124
1125 // Those were all the cases that could result in a primitive
1126 if (allowBoxing) {
1127 if (thentype.isPrimitive())
1128 thentype = types.boxedClass(thentype).type;
1129 if (elsetype.isPrimitive())
1130 elsetype = types.boxedClass(elsetype).type;
1131 }
1132
1133 if (types.isSubtype(thentype, elsetype))
1134 return elsetype.baseType();
1135 if (types.isSubtype(elsetype, thentype))
1136 return thentype.baseType();
1137
1138 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1139 log.error(pos, "neither.conditional.subtype",
1140 thentype, elsetype);
1141 return thentype.baseType();
1142 }
1143
1144 // both are known to be reference types. The result is
1145 // lub(thentype,elsetype). This cannot fail, as it will
1146 // always be possible to infer "Object" if nothing better.
1147 return types.lub(thentype.baseType(), elsetype.baseType());
1148 }
1149
1150 public void visitIf(JCIf tree) {
1151 attribExpr(tree.cond, env, syms.booleanType);
1152 attribStat(tree.thenpart, env);
1153 if (tree.elsepart != null)
1154 attribStat(tree.elsepart, env);
1155 chk.checkEmptyIf(tree);
1156 result = null;
1157 }
1158
1159 public void visitExec(JCExpressionStatement tree) {
1160 attribExpr(tree.expr, env);
1161 result = null;
1162 }
1163
1164 public void visitBreak(JCBreak tree) {
1165 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1166 result = null;
1167 }
1168
1169 public void visitContinue(JCContinue tree) {
1170 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1171 result = null;
1172 }
1173 //where
1174 /** Return the target of a break or continue statement, if it exists,
1175 * report an error if not.
1176 * Note: The target of a labelled break or continue is the
1177 * (non-labelled) statement tree referred to by the label,
1178 * not the tree representing the labelled statement itself.
1179 *
1180 * @param pos The position to be used for error diagnostics
1181 * @param tag The tag of the jump statement. This is either
1182 * Tree.BREAK or Tree.CONTINUE.
1183 * @param label The label of the jump statement, or null if no
1184 * label is given.
1185 * @param env The environment current at the jump statement.
1186 */
1187 private JCTree findJumpTarget(DiagnosticPosition pos,
1188 int tag,
1189 Name label,
1190 Env<AttrContext> env) {
1191 // Search environments outwards from the point of jump.
1192 Env<AttrContext> env1 = env;
1193 LOOP:
1194 while (env1 != null) {
1195 switch (env1.tree.getTag()) {
1196 case JCTree.LABELLED:
1197 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1198 if (label == labelled.label) {
1199 // If jump is a continue, check that target is a loop.
1200 if (tag == JCTree.CONTINUE) {
1201 if (labelled.body.getTag() != JCTree.DOLOOP &&
1202 labelled.body.getTag() != JCTree.WHILELOOP &&
1203 labelled.body.getTag() != JCTree.FORLOOP &&
1204 labelled.body.getTag() != JCTree.FOREACHLOOP)
1205 log.error(pos, "not.loop.label", label);
1206 // Found labelled statement target, now go inwards
1207 // to next non-labelled tree.
1208 return TreeInfo.referencedStatement(labelled);
1209 } else {
1210 return labelled;
1211 }
1212 }
1213 break;
1214 case JCTree.DOLOOP:
1215 case JCTree.WHILELOOP:
1216 case JCTree.FORLOOP:
1217 case JCTree.FOREACHLOOP:
1218 if (label == null) return env1.tree;
1219 break;
1220 case JCTree.SWITCH:
1221 if (label == null && tag == JCTree.BREAK) return env1.tree;
1222 break;
1223 case JCTree.METHODDEF:
1224 case JCTree.CLASSDEF:
1225 break LOOP;
1226 default:
1227 }
1228 env1 = env1.next;
1229 }
1230 if (label != null)
1231 log.error(pos, "undef.label", label);
1232 else if (tag == JCTree.CONTINUE)
1233 log.error(pos, "cont.outside.loop");
1234 else
1235 log.error(pos, "break.outside.switch.loop");
1236 return null;
1237 }
1238
1239 public void visitReturn(JCReturn tree) {
1240 // Check that there is an enclosing method which is
1241 // nested within than the enclosing class.
1242 if (env.enclMethod == null ||
1243 env.enclMethod.sym.owner != env.enclClass.sym) {
1244 log.error(tree.pos(), "ret.outside.meth");
1245
1246 } else {
1247 // Attribute return expression, if it exists, and check that
1248 // it conforms to result type of enclosing method.
1249 Symbol m = env.enclMethod.sym;
1250 if (m.type.getReturnType().tag == VOID) {
1251 if (tree.expr != null)
1252 log.error(tree.expr.pos(),
1253 "cant.ret.val.from.meth.decl.void");
1254 } else if (tree.expr == null) {
1255 log.error(tree.pos(), "missing.ret.val");
1256 } else {
1257 attribExpr(tree.expr, env, m.type.getReturnType());
1258 }
1259 }
1260 result = null;
1261 }
1262
1263 public void visitThrow(JCThrow tree) {
1264 attribExpr(tree.expr, env, syms.throwableType);
1265 result = null;
1266 }
1267
1268 public void visitAssert(JCAssert tree) {
1269 attribExpr(tree.cond, env, syms.booleanType);
1270 if (tree.detail != null) {
1271 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1272 }
1273 result = null;
1274 }
1275
1276 /** Visitor method for method invocations.
1277 * NOTE: The method part of an application will have in its type field
1278 * the return type of the method, not the method's type itself!
1279 */
1280 public void visitApply(JCMethodInvocation tree) {
1281 // The local environment of a method application is
1282 // a new environment nested in the current one.
1283 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1284
1285 // The types of the actual method arguments.
1286 List<Type> argtypes;
1287
1288 // The types of the actual method type arguments.
1289 List<Type> typeargtypes = null;
1290 boolean typeargtypesNonRefOK = false;
1291
1292 Name methName = TreeInfo.name(tree.meth);
1293
1294 boolean isConstructorCall =
1295 methName == names._this || methName == names._super;
1296
1297 if (isConstructorCall) {
1298 // We are seeing a ...this(...) or ...super(...) call.
1299 // Check that this is the first statement in a constructor.
1300 if (checkFirstConstructorStat(tree, env)) {
1301
1302 // Record the fact
1303 // that this is a constructor call (using isSelfCall).
1304 localEnv.info.isSelfCall = true;
1305
1306 // Attribute arguments, yielding list of argument types.
1307 argtypes = attribArgs(tree.args, localEnv);
1308 typeargtypes = attribTypes(tree.typeargs, localEnv);
1309
1310 // Variable `site' points to the class in which the called
1311 // constructor is defined.
1312 Type site = env.enclClass.sym.type;
1313 if (methName == names._super) {
1314 if (site == syms.objectType) {
1315 log.error(tree.meth.pos(), "no.superclass", site);
1316 site = types.createErrorType(syms.objectType);
1317 } else {
1318 site = types.supertype(site);
1319 }
1320 }
1321
1322 if (site.tag == CLASS) {
1323 Type encl = site.getEnclosingType();
1324 while (encl != null && encl.tag == TYPEVAR)
1325 encl = encl.getUpperBound();
1326 if (encl.tag == CLASS) {
1327 // we are calling a nested class
1328
1329 if (tree.meth.getTag() == JCTree.SELECT) {
1330 JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1331
1332 // We are seeing a prefixed call, of the form
1333 // <expr>.super(...).
1334 // Check that the prefix expression conforms
1335 // to the outer instance type of the class.
1336 chk.checkRefType(qualifier.pos(),
1337 attribExpr(qualifier, localEnv,
1338 encl));
1339 } else if (methName == names._super) {
1340 // qualifier omitted; check for existence
1341 // of an appropriate implicit qualifier.
1342 rs.resolveImplicitThis(tree.meth.pos(),
1343 localEnv, site);
1344 }
1345 } else if (tree.meth.getTag() == JCTree.SELECT) {
1346 log.error(tree.meth.pos(), "illegal.qual.not.icls",
1347 site.tsym);
1348 }
1349
1350 // if we're calling a java.lang.Enum constructor,
1351 // prefix the implicit String and int parameters
1352 if (site.tsym == syms.enumSym && allowEnums)
1353 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1354
1355 // Resolve the called constructor under the assumption
1356 // that we are referring to a superclass instance of the
1357 // current instance (JLS ???).
1358 boolean selectSuperPrev = localEnv.info.selectSuper;
1359 localEnv.info.selectSuper = true;
1360 localEnv.info.varArgs = false;
1361 Symbol sym = rs.resolveConstructor(
1362 tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1363 localEnv.info.selectSuper = selectSuperPrev;
1364
1365 // Set method symbol to resolved constructor...
1366 TreeInfo.setSymbol(tree.meth, sym);
1367
1368 // ...and check that it is legal in the current context.
1369 // (this will also set the tree's type)
1370 Type mpt = newMethTemplate(argtypes, typeargtypes);
1371 checkId(tree.meth, site, sym, localEnv, MTH,
1372 mpt, tree.varargsElement != null);
1373 }
1374 // Otherwise, `site' is an error type and we do nothing
1375 }
1376 result = tree.type = syms.voidType;
1377 } else {
1378 // Otherwise, we are seeing a regular method call.
1379 // Attribute the arguments, yielding list of argument types, ...
1380 argtypes = attribArgs(tree.args, localEnv);
1381 typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
1382
1383 // ... and attribute the method using as a prototype a methodtype
1384 // whose formal argument types is exactly the list of actual
1385 // arguments (this will also set the method symbol).
1386 Type mpt = newMethTemplate(argtypes, typeargtypes);
1387 localEnv.info.varArgs = false;
1388 Type mtype = attribExpr(tree.meth, localEnv, mpt);
1389 if (localEnv.info.varArgs)
1390 assert mtype.isErroneous() || tree.varargsElement != null;
1391
1392 // Compute the result type.
1393 Type restype = mtype.getReturnType();
1394 assert restype.tag != WILDCARD : mtype;
1395
1396 // as a special case, array.clone() has a result that is
1397 // the same as static type of the array being cloned
1398 if (tree.meth.getTag() == JCTree.SELECT &&
1399 allowCovariantReturns &&
1400 methName == names.clone &&
1401 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1402 restype = ((JCFieldAccess) tree.meth).selected.type;
1403
1404 // as a special case, x.getClass() has type Class<? extends |X|>
1405 if (allowGenerics &&
1406 methName == names.getClass && tree.args.isEmpty()) {
1407 Type qualifier = (tree.meth.getTag() == JCTree.SELECT)
1408 ? ((JCFieldAccess) tree.meth).selected.type
1409 : env.enclClass.sym.type;
1410 restype = new
1411 ClassType(restype.getEnclosingType(),
1412 List.<Type>of(new WildcardType(types.erasure(qualifier),
1413 BoundKind.EXTENDS,
1414 syms.boundClass)),
1415 restype.tsym);
1416 }
1417
1418 // as a special case, MethodHandle.<T>invoke(abc) and InvokeDynamic.<T>foo(abc)
1419 // has type <T>, and T can be a primitive type.
1420 if (tree.meth.getTag() == JCTree.SELECT && !typeargtypes.isEmpty()) {
1421 JCFieldAccess mfield = (JCFieldAccess) tree.meth;
1422 if ((mfield.selected.type.tsym != null &&
1423 (mfield.selected.type.tsym.flags() & POLYMORPHIC_SIGNATURE) != 0)
1424 ||
1425 (mfield.sym != null &&
1426 (mfield.sym.flags() & POLYMORPHIC_SIGNATURE) != 0)) {
1427 assert types.isSameType(restype, typeargtypes.head) : mtype;
1428 assert mfield.selected.type == syms.methodHandleType
1429 || mfield.selected.type == syms.invokeDynamicType;
1430 typeargtypesNonRefOK = true;
1431 }
1432 }
1433
1434 if (!typeargtypesNonRefOK) {
1435 chk.checkRefTypes(tree.typeargs, typeargtypes);
1436 }
1437
1438 // Check that value of resulting type is admissible in the
1439 // current context. Also, capture the return type
1440 result = check(tree, capture(restype), VAL, pkind, pt);
1441 }
1442 chk.validate(tree.typeargs, localEnv);
1443 }
1444 //where
1445 /** Check that given application node appears as first statement
1446 * in a constructor call.
1447 * @param tree The application node
1448 * @param env The environment current at the application.
1449 */
1450 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1451 JCMethodDecl enclMethod = env.enclMethod;
1452 if (enclMethod != null && enclMethod.name == names.init) {
1453 JCBlock body = enclMethod.body;
1454 if (body.stats.head.getTag() == JCTree.EXEC &&
1455 ((JCExpressionStatement) body.stats.head).expr == tree)
1456 return true;
1457 }
1458 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1459 TreeInfo.name(tree.meth));
1460 return false;
1461 }
1462
1463 /** Obtain a method type with given argument types.
1464 */
1465 Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
1466 MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
1467 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1468 }
1469
1470 public void visitNewClass(JCNewClass tree) {
1471 Type owntype = types.createErrorType(tree.type);
1472
1473 // The local environment of a class creation is
1474 // a new environment nested in the current one.
1475 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1476
1477 // The anonymous inner class definition of the new expression,
1478 // if one is defined by it.
1479 JCClassDecl cdef = tree.def;
1480
1481 // If enclosing class is given, attribute it, and
1482 // complete class name to be fully qualified
1483 JCExpression clazz = tree.clazz; // Class field following new
1484 JCExpression clazzid = // Identifier in class field
1485 (clazz.getTag() == JCTree.TYPEAPPLY)
1486 ? ((JCTypeApply) clazz).clazz
1487 : clazz;
1488
1489 JCExpression clazzid1 = clazzid; // The same in fully qualified form
1490
1491 if (tree.encl != null) {
1492 // We are seeing a qualified new, of the form
1493 // <expr>.new C <...> (...) ...
1494 // In this case, we let clazz stand for the name of the
1495 // allocated class C prefixed with the type of the qualifier
1496 // expression, so that we can
1497 // resolve it with standard techniques later. I.e., if
1498 // <expr> has type T, then <expr>.new C <...> (...)
1499 // yields a clazz T.C.
1500 Type encltype = chk.checkRefType(tree.encl.pos(),
1501 attribExpr(tree.encl, env));
1502 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1503 ((JCIdent) clazzid).name);
1504 if (clazz.getTag() == JCTree.TYPEAPPLY)
1505 clazz = make.at(tree.pos).
1506 TypeApply(clazzid1,
1507 ((JCTypeApply) clazz).arguments);
1508 else
1509 clazz = clazzid1;
1510 }
1511
1512 // Attribute clazz expression and store
1513 // symbol + type back into the attributed tree.
1514 Type clazztype = attribType(clazz, env);
1515 Pair<Scope,Scope> mapping = getSyntheticScopeMapping(clazztype);
1516 if (!TreeInfo.isDiamond(tree)) {
1517 clazztype = chk.checkClassType(
1518 tree.clazz.pos(), clazztype, true);
1519 }
1520 chk.validate(clazz, localEnv);
1521 if (tree.encl != null) {
1522 // We have to work in this case to store
1523 // symbol + type back into the attributed tree.
1524 tree.clazz.type = clazztype;
1525 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1526 clazzid.type = ((JCIdent) clazzid).sym.type;
1527 if (!clazztype.isErroneous()) {
1528 if (cdef != null && clazztype.tsym.isInterface()) {
1529 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1530 } else if (clazztype.tsym.isStatic()) {
1531 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1532 }
1533 }
1534 } else if (!clazztype.tsym.isInterface() &&
1535 clazztype.getEnclosingType().tag == CLASS) {
1536 // Check for the existence of an apropos outer instance
1537 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1538 }
1539
1540 // Attribute constructor arguments.
1541 List<Type> argtypes = attribArgs(tree.args, localEnv);
1542 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1543
1544 if (TreeInfo.isDiamond(tree)) {
1545 clazztype = attribDiamond(localEnv, tree, clazztype, mapping, argtypes, typeargtypes, true);
1546 clazz.type = clazztype;
1547 }
1548
1549 // If we have made no mistakes in the class type...
1550 if (clazztype.tag == CLASS) {
1551 // Enums may not be instantiated except implicitly
1552 if (allowEnums &&
1553 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1554 (env.tree.getTag() != JCTree.VARDEF ||
1555 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1556 ((JCVariableDecl) env.tree).init != tree))
1557 log.error(tree.pos(), "enum.cant.be.instantiated");
1558 // Check that class is not abstract
1559 if (cdef == null &&
1560 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1561 log.error(tree.pos(), "abstract.cant.be.instantiated",
1562 clazztype.tsym);
1563 } else if (cdef != null && clazztype.tsym.isInterface()) {
1564 // Check that no constructor arguments are given to
1565 // anonymous classes implementing an interface
1566 if (!argtypes.isEmpty())
1567 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1568
1569 if (!typeargtypes.isEmpty())
1570 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1571
1572 // Error recovery: pretend no arguments were supplied.
1573 argtypes = List.nil();
1574 typeargtypes = List.nil();
1575 }
1576
1577 // Resolve the called constructor under the assumption
1578 // that we are referring to a superclass instance of the
1579 // current instance (JLS ???).
1580 else {
1581 localEnv.info.selectSuper = cdef != null;
1582 localEnv.info.varArgs = false;
1583 tree.constructor = rs.resolveConstructor(
1584 tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
1585 tree.constructorType = checkMethod(clazztype,
1586 tree.constructor,
1587 localEnv,
1588 tree.args,
1589 argtypes,
1590 typeargtypes,
1591 localEnv.info.varArgs);
1592 if (localEnv.info.varArgs)
1593 assert tree.constructorType.isErroneous() || tree.varargsElement != null;
1594 }
1595
1596 if (cdef != null) {
1597 // We are seeing an anonymous class instance creation.
1598 // In this case, the class instance creation
1599 // expression
1600 //
1601 // E.new <typeargs1>C<typargs2>(args) { ... }
1602 //
1603 // is represented internally as
1604 //
1605 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1606 //
1607 // This expression is then *transformed* as follows:
1608 //
1609 // (1) add a STATIC flag to the class definition
1610 // if the current environment is static
1611 // (2) add an extends or implements clause
1612 // (3) add a constructor.
1613 //
1614 // For instance, if C is a class, and ET is the type of E,
1615 // the expression
1616 //
1617 // E.new <typeargs1>C<typargs2>(args) { ... }
1618 //
1619 // is translated to (where X is a fresh name and typarams is the
1620 // parameter list of the super constructor):
1621 //
1622 // new <typeargs1>X(<*nullchk*>E, args) where
1623 // X extends C<typargs2> {
1624 // <typarams> X(ET e, args) {
1625 // e.<typeargs1>super(args)
1626 // }
1627 // ...
1628 // }
1629 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1630
1631 if (clazztype.tsym.isInterface()) {
1632 cdef.implementing = List.of(clazz);
1633 } else {
1634 cdef.extending = clazz;
1635 }
1636
1637 attribStat(cdef, localEnv);
1638
1639 // If an outer instance is given,
1640 // prefix it to the constructor arguments
1641 // and delete it from the new expression
1642 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1643 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1644 argtypes = argtypes.prepend(tree.encl.type);
1645 tree.encl = null;
1646 }
1647
1648 // Reassign clazztype and recompute constructor.
1649 clazztype = cdef.sym.type;
1650 Symbol sym = rs.resolveConstructor(
1651 tree.pos(), localEnv, clazztype, argtypes,
1652 typeargtypes, true, tree.varargsElement != null);
1653 assert sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous();
1654 tree.constructor = sym;
1655 if (tree.constructor.kind > ERRONEOUS) {
1656 tree.constructorType = syms.errType;
1657 }
1658 else {
1659 tree.constructorType = checkMethod(clazztype,
1660 tree.constructor,
1661 localEnv,
1662 tree.args,
1663 argtypes,
1664 typeargtypes,
1665 localEnv.info.varArgs);
1666 }
1667 }
1668
1669 if (tree.constructor != null && tree.constructor.kind == MTH)
1670 owntype = clazztype;
1671 }
1672 result = check(tree, owntype, VAL, pkind, pt);
1673 chk.validate(tree.typeargs, localEnv);
1674 }
1675
1676 Type attribDiamond(Env<AttrContext> env,
1677 JCNewClass tree,
1678 Type clazztype,
1679 Pair<Scope, Scope> mapping,
1680 List<Type> argtypes,
1681 List<Type> typeargtypes,
1682 boolean reportErrors) {
1683 if (clazztype.isErroneous() || mapping == erroneousMapping) {
1684 //if the type of the instance creation expression is erroneous,
1685 //or something prevented us to form a valid mapping, return the
1686 //(possibly erroneous) type unchanged
1687 return clazztype;
1688 }
1689 else if (clazztype.isInterface()) {
1690 //if the type of the instance creation expression is an interface
1691 //skip the method resolution step (JLS 15.12.2.7). The type to be
1692 //inferred is of the kind <X1,X2, ... Xn>C<X1,X2, ... Xn>
1693 clazztype = new ForAll(clazztype.tsym.type.allparams(),
1694 clazztype.tsym.type);
1695 } else {
1696 //if the type of the instance creation expression is a class type
1697 //apply method resolution inference (JLS 15.12.2.7). The return type
1698 //of the resolved constructor will be a partially instantiated type
1699 ((ClassSymbol) clazztype.tsym).members_field = mapping.snd;
1700 Symbol constructor;
1701 try {
1702 constructor = rs.resolveDiamond(tree.pos(),
1703 env,
1704 clazztype.tsym.type,
1705 argtypes,
1706 typeargtypes, reportErrors);
1707 } finally {
1708 ((ClassSymbol) clazztype.tsym).members_field = mapping.fst;
1709 }
1710 if (constructor.kind == MTH) {
1711 ClassType ct = new ClassType(clazztype.getEnclosingType(),
1712 clazztype.tsym.type.getTypeArguments(),
1713 clazztype.tsym);
1714 clazztype = checkMethod(ct,
1715 constructor,
1716 env,
1717 tree.args,
1718 argtypes,
1719 typeargtypes,
1720 env.info.varArgs).getReturnType();
1721 } else {
1722 clazztype = syms.errType;
1723 }
1724 }
1725 if (clazztype.tag == FORALL && !pt.isErroneous()) {
1726 //if the resolved constructor's return type has some uninferred
1727 //type-variables, infer them using the expected type and declared
1728 //bounds (JLS 15.12.2.8).
1729 try {
1730 clazztype = infer.instantiateExpr((ForAll) clazztype,
1731 pt.tag == NONE ? syms.objectType : pt,
1732 Warner.noWarnings);
1733 } catch (Infer.InferenceException ex) {
1734 //an error occurred while inferring uninstantiated type-variables
1735 //we need to optionally report an error
1736 if (reportErrors) {
1737 log.error(tree.clazz.pos(),
1738 "cant.apply.diamond.1",
1739 diags.fragment("diamond", clazztype.tsym),
1740 ex.diagnostic);
1741 }
1742 }
1743 }
1744 if (reportErrors) {
1745 clazztype = chk.checkClassType(tree.clazz.pos(),
1746 clazztype,
1747 true);
1748 if (clazztype.tag == CLASS) {
1749 List<Type> invalidDiamondArgs = chk.checkDiamond((ClassType)clazztype);
1750 if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
1751 //one or more types inferred in the previous steps is either a
1752 //captured type or an intersection type --- we need to report an error.
1753 String subkey = invalidDiamondArgs.size() > 1 ?
1754 "diamond.invalid.args" :
1755 "diamond.invalid.arg";
1756 //The error message is of the kind:
1757 //
1758 //cannot infer type arguments for {clazztype}<>;
1759 //reason: {subkey}
1760 //
1761 //where subkey is a fragment of the kind:
1762 //
1763 //type argument(s) {invalidDiamondArgs} inferred for {clazztype}<> is not allowed in this context
1764 log.error(tree.clazz.pos(),
1765 "cant.apply.diamond.1",
1766 diags.fragment("diamond", clazztype.tsym),
1767 diags.fragment(subkey,
1768 invalidDiamondArgs,
1769 diags.fragment("diamond", clazztype.tsym)));
1770 }
1771 }
1772 }
1773 return clazztype;
1774 }
1775
1776 /** Creates a synthetic scope containing fake generic constructors.
1777 * Assuming that the original scope contains a constructor of the kind:
1778 * Foo(X x, Y y), where X,Y are class type-variables declared in Foo,
1779 * the synthetic scope is added a generic constructor of the kind:
1780 * <X,Y>Foo<X,Y>(X x, Y y). This is crucial in order to enable diamond
1781 * inference. The inferred return type of the synthetic constructor IS
1782 * the inferred type for the diamond operator.
1783 */
1784 private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype) {
1785 if (ctype.tag != CLASS) {
1786 return erroneousMapping;
1787 }
1788 Pair<Scope, Scope> mapping =
1789 new Pair<Scope, Scope>(ctype.tsym.members(), new Scope(ctype.tsym));
1790 List<Type> typevars = ctype.tsym.type.getTypeArguments();
1791 for (Scope.Entry e = mapping.fst.lookup(names.init);
1792 e.scope != null;
1793 e = e.next()) {
1794 MethodSymbol newConstr = (MethodSymbol) e.sym.clone(ctype.tsym);
1795 newConstr.name = names.init;
1796 List<Type> oldTypeargs = List.nil();
1797 if (newConstr.type.tag == FORALL) {
1798 oldTypeargs = ((ForAll) newConstr.type).tvars;
1799 }
1800 newConstr.type = new MethodType(newConstr.type.getParameterTypes(),
1801 new ClassType(ctype.getEnclosingType(), ctype.tsym.type.getTypeArguments(), ctype.tsym),
1802 newConstr.type.getThrownTypes(),
1803 syms.methodClass);
1804 newConstr.type = new ForAll(typevars.prependList(oldTypeargs), newConstr.type);
1805 mapping.snd.enter(newConstr);
1806 }
1807 return mapping;
1808 }
1809
1810 private final Pair<Scope,Scope> erroneousMapping = new Pair<Scope,Scope>(null, null);
1811
1812 /** Make an attributed null check tree.
1813 */
1814 public JCExpression makeNullCheck(JCExpression arg) {
1815 // optimization: X.this is never null; skip null check
1816 Name name = TreeInfo.name(arg);
1817 if (name == names._this || name == names._super) return arg;
1818
1819 int optag = JCTree.NULLCHK;
1820 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1821 tree.operator = syms.nullcheck;
1822 tree.type = arg.type;
1823 return tree;
1824 }
1825
1826 public void visitNewArray(JCNewArray tree) {
1827 Type owntype = types.createErrorType(tree.type);
1828 Type elemtype;
1829 if (tree.elemtype != null) {
1830 elemtype = attribType(tree.elemtype, env);
1831 chk.validate(tree.elemtype, env);
1832 owntype = elemtype;
1833 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1834 attribExpr(l.head, env, syms.intType);
1835 owntype = new ArrayType(owntype, syms.arrayClass);
1836 }
1837 } else {
1838 // we are seeing an untyped aggregate { ... }
1839 // this is allowed only if the prototype is an array
1840 if (pt.tag == ARRAY) {
1841 elemtype = types.elemtype(pt);
1842 } else {
1843 if (pt.tag != ERROR) {
1844 log.error(tree.pos(), "illegal.initializer.for.type",
1845 pt);
1846 }
1847 elemtype = types.createErrorType(pt);
1848 }
1849 }
1850 if (tree.elems != null) {
1851 attribExprs(tree.elems, env, elemtype);
1852 owntype = new ArrayType(elemtype, syms.arrayClass);
1853 }
1854 if (!types.isReifiable(elemtype))
1855 log.error(tree.pos(), "generic.array.creation");
1856 result = check(tree, owntype, VAL, pkind, pt);
1857 }
1858
1859 public void visitParens(JCParens tree) {
1860 Type owntype = attribTree(tree.expr, env, pkind, pt);
1861 result = check(tree, owntype, pkind, pkind, pt);
1862 Symbol sym = TreeInfo.symbol(tree);
1863 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1864 log.error(tree.pos(), "illegal.start.of.type");
1865 }
1866
1867 public void visitAssign(JCAssign tree) {
1868 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1869 Type capturedType = capture(owntype);
1870 attribExpr(tree.rhs, env, owntype);
1871 result = check(tree, capturedType, VAL, pkind, pt);
1872 }
1873
1874 public void visitAssignop(JCAssignOp tree) {
1875 // Attribute arguments.
1876 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
1877 Type operand = attribExpr(tree.rhs, env);
1878 // Find operator.
1879 Symbol operator = tree.operator = rs.resolveBinaryOperator(
1880 tree.pos(), tree.getTag() - JCTree.ASGOffset, env,
1881 owntype, operand);
1882
1883 if (operator.kind == MTH) {
1884 chk.checkOperator(tree.pos(),
1885 (OperatorSymbol)operator,
1886 tree.getTag() - JCTree.ASGOffset,
1887 owntype,
1888 operand);
1889 chk.checkDivZero(tree.rhs.pos(), operator, operand);
1890 chk.checkCastable(tree.rhs.pos(),
1891 operator.type.getReturnType(),
1892 owntype);
1893 }
1894 result = check(tree, owntype, VAL, pkind, pt);
1895 }
1896
1897 public void visitUnary(JCUnary tree) {
1898 // Attribute arguments.
1899 Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1900 ? attribTree(tree.arg, env, VAR, Type.noType)
1901 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
1902
1903 // Find operator.
1904 Symbol operator = tree.operator =
1905 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
1906
1907 Type owntype = types.createErrorType(tree.type);
1908 if (operator.kind == MTH) {
1909 owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1910 ? tree.arg.type
1911 : operator.type.getReturnType();
1912 int opc = ((OperatorSymbol)operator).opcode;
1913
1914 // If the argument is constant, fold it.
1915 if (argtype.constValue() != null) {
1916 Type ctype = cfolder.fold1(opc, argtype);
1917 if (ctype != null) {
1918 owntype = cfolder.coerce(ctype, owntype);
1919
1920 // Remove constant types from arguments to
1921 // conserve space. The parser will fold concatenations
1922 // of string literals; the code here also
1923 // gets rid of intermediate results when some of the
1924 // operands are constant identifiers.
1925 if (tree.arg.type.tsym == syms.stringType.tsym) {
1926 tree.arg.type = syms.stringType;
1927 }
1928 }
1929 }
1930 }
1931 result = check(tree, owntype, VAL, pkind, pt);
1932 }
1933
1934 public void visitBinary(JCBinary tree) {
1935 // Attribute arguments.
1936 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
1937 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
1938
1939 // Find operator.
1940 Symbol operator = tree.operator =
1941 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
1942
1943 Type owntype = types.createErrorType(tree.type);
1944 if (operator.kind == MTH) {
1945 owntype = operator.type.getReturnType();
1946 int opc = chk.checkOperator(tree.lhs.pos(),
1947 (OperatorSymbol)operator,
1948 tree.getTag(),
1949 left,
1950 right);
1951
1952 // If both arguments are constants, fold them.
1953 if (left.constValue() != null && right.constValue() != null) {
1954 Type ctype = cfolder.fold2(opc, left, right);
1955 if (ctype != null) {
1956 owntype = cfolder.coerce(ctype, owntype);
1957
1958 // Remove constant types from arguments to
1959 // conserve space. The parser will fold concatenations
1960 // of string literals; the code here also
1961 // gets rid of intermediate results when some of the
1962 // operands are constant identifiers.
1963 if (tree.lhs.type.tsym == syms.stringType.tsym) {
1964 tree.lhs.type = syms.stringType;
1965 }
1966 if (tree.rhs.type.tsym == syms.stringType.tsym) {
1967 tree.rhs.type = syms.stringType;
1968 }
1969 }
1970 }
1971
1972 // Check that argument types of a reference ==, != are
1973 // castable to each other, (JLS???).
1974 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
1975 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
1976 log.error(tree.pos(), "incomparable.types", left, right);
1977 }
1978 }
1979
1980 chk.checkDivZero(tree.rhs.pos(), operator, right);
1981 }
1982 result = check(tree, owntype, VAL, pkind, pt);
1983 }
1984
1985 public void visitTypeCast(JCTypeCast tree) {
1986 Type clazztype = attribType(tree.clazz, env);
1987 chk.validate(tree.clazz, env);
1988 Type exprtype = attribExpr(tree.expr, env, Infer.anyPoly);
1989 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1990 if (exprtype.constValue() != null)
1991 owntype = cfolder.coerce(exprtype, owntype);
1992 result = check(tree, capture(owntype), VAL, pkind, pt);
1993 }
1994
1995 public void visitTypeTest(JCInstanceOf tree) {
1996 Type exprtype = chk.checkNullOrRefType(
1997 tree.expr.pos(), attribExpr(tree.expr, env));
1998 Type clazztype = chk.checkReifiableReferenceType(
1999 tree.clazz.pos(), attribType(tree.clazz, env));
2000 chk.validate(tree.clazz, env);
2001 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2002 result = check(tree, syms.booleanType, VAL, pkind, pt);
2003 }
2004
2005 public void visitIndexed(JCArrayAccess tree) {
2006 Type owntype = types.createErrorType(tree.type);
2007 Type atype = attribExpr(tree.indexed, env);
2008 attribExpr(tree.index, env, syms.intType);
2009 if (types.isArray(atype))
2010 owntype = types.elemtype(atype);
2011 else if (atype.tag != ERROR)
2012 log.error(tree.pos(), "array.req.but.found", atype);
2013 if ((pkind & VAR) == 0) owntype = capture(owntype);
2014 result = check(tree, owntype, VAR, pkind, pt);
2015 }
2016
2017 public void visitIdent(JCIdent tree) {
2018 Symbol sym;
2019 boolean varArgs = false;
2020
2021 // Find symbol
2022 if (pt.tag == METHOD || pt.tag == FORALL) {
2023 // If we are looking for a method, the prototype `pt' will be a
2024 // method type with the type of the call's arguments as parameters.
2025 env.info.varArgs = false;
2026 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
2027 varArgs = env.info.varArgs;
2028 } else if (tree.sym != null && tree.sym.kind != VAR) {
2029 sym = tree.sym;
2030 } else {
2031 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
2032 }
2033 tree.sym = sym;
2034
2035 // (1) Also find the environment current for the class where
2036 // sym is defined (`symEnv').
2037 // Only for pre-tiger versions (1.4 and earlier):
2038 // (2) Also determine whether we access symbol out of an anonymous
2039 // class in a this or super call. This is illegal for instance
2040 // members since such classes don't carry a this$n link.
2041 // (`noOuterThisPath').
2042 Env<AttrContext> symEnv = env;
2043 boolean noOuterThisPath = false;
2044 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
2045 (sym.kind & (VAR | MTH | TYP)) != 0 &&
2046 sym.owner.kind == TYP &&
2047 tree.name != names._this && tree.name != names._super) {
2048
2049 // Find environment in which identifier is defined.
2050 while (symEnv.outer != null &&
2051 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
2052 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
2053 noOuterThisPath = !allowAnonOuterThis;
2054 symEnv = symEnv.outer;
2055 }
2056 }
2057
2058 // If symbol is a variable, ...
2059 if (sym.kind == VAR) {
2060 VarSymbol v = (VarSymbol)sym;
2061
2062 // ..., evaluate its initializer, if it has one, and check for
2063 // illegal forward reference.
2064 checkInit(tree, env, v, false);
2065
2066 // If symbol is a local variable accessed from an embedded
2067 // inner class check that it is final.
2068 if (v.owner.kind == MTH &&
2069 v.owner != env.info.scope.owner &&
2070 (v.flags_field & FINAL) == 0) {
2071 log.error(tree.pos(),
2072 "local.var.accessed.from.icls.needs.final",
2073 v);
2074 }
2075
2076 // If we are expecting a variable (as opposed to a value), check
2077 // that the variable is assignable in the current environment.
2078 if (pkind == VAR)
2079 checkAssignable(tree.pos(), v, null, env);
2080 }
2081
2082 // In a constructor body,
2083 // if symbol is a field or instance method, check that it is
2084 // not accessed before the supertype constructor is called.
2085 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
2086 (sym.kind & (VAR | MTH)) != 0 &&
2087 sym.owner.kind == TYP &&
2088 (sym.flags() & STATIC) == 0) {
2089 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
2090 }
2091 Env<AttrContext> env1 = env;
2092 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
2093 // If the found symbol is inaccessible, then it is
2094 // accessed through an enclosing instance. Locate this
2095 // enclosing instance:
2096 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
2097 env1 = env1.outer;
2098 }
2099 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
2100 }
2101
2102 public void visitSelect(JCFieldAccess tree) {
2103 // Determine the expected kind of the qualifier expression.
2104 int skind = 0;
2105 if (tree.name == names._this || tree.name == names._super ||
2106 tree.name == names._class)
2107 {
2108 skind = TYP;
2109 } else {
2110 if ((pkind & PCK) != 0) skind = skind | PCK;
2111 if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
2112 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
2113 }
2114
2115 // Attribute the qualifier expression, and determine its symbol (if any).
2116 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
2117 if ((pkind & (PCK | TYP)) == 0)
2118 site = capture(site); // Capture field access
2119
2120 // don't allow T.class T[].class, etc
2121 if (skind == TYP) {
2122 Type elt = site;
2123 while (elt.tag == ARRAY)
2124 elt = ((ArrayType)elt).elemtype;
2125 if (elt.tag == TYPEVAR) {
2126 log.error(tree.pos(), "type.var.cant.be.deref");
2127 result = types.createErrorType(tree.type);
2128 return;
2129 }
2130 }
2131
2132 // If qualifier symbol is a type or `super', assert `selectSuper'
2133 // for the selection. This is relevant for determining whether
2134 // protected symbols are accessible.
2135 Symbol sitesym = TreeInfo.symbol(tree.selected);
2136 boolean selectSuperPrev = env.info.selectSuper;
2137 env.info.selectSuper =
2138 sitesym != null &&
2139 sitesym.name == names._super;
2140
2141 // If selected expression is polymorphic, strip
2142 // type parameters and remember in env.info.tvars, so that
2143 // they can be added later (in Attr.checkId and Infer.instantiateMethod).
2144 if (tree.selected.type.tag == FORALL) {
2145 ForAll pstype = (ForAll)tree.selected.type;
2146 env.info.tvars = pstype.tvars;
2147 site = tree.selected.type = pstype.qtype;
2148 }
2149
2150 // Determine the symbol represented by the selection.
2151 env.info.varArgs = false;
2152 Symbol sym = selectSym(tree, site, env, pt, pkind);
2153 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
2154 site = capture(site);
2155 sym = selectSym(tree, site, env, pt, pkind);
2156 }
2157 boolean varArgs = env.info.varArgs;
2158 tree.sym = sym;
2159
2160 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
2161 while (site.tag == TYPEVAR) site = site.getUpperBound();
2162 site = capture(site);
2163 }
2164
2165 // If that symbol is a variable, ...
2166 if (sym.kind == VAR) {
2167 VarSymbol v = (VarSymbol)sym;
2168
2169 // ..., evaluate its initializer, if it has one, and check for
2170 // illegal forward reference.
2171 checkInit(tree, env, v, true);
2172
2173 // If we are expecting a variable (as opposed to a value), check
2174 // that the variable is assignable in the current environment.
2175 if (pkind == VAR)
2176 checkAssignable(tree.pos(), v, tree.selected, env);
2177 }
2178
2179 if (sitesym != null &&
2180 sitesym.kind == VAR &&
2181 ((VarSymbol)sitesym).isResourceVariable() &&
2182 sym.kind == MTH &&
2183 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
2184 env.info.lint.isEnabled(Lint.LintCategory.ARM)) {
2185 log.warning(tree, "arm.explicit.close.call");
2186 }
2187
2188 // Disallow selecting a type from an expression
2189 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
2190 tree.type = check(tree.selected, pt,
2191 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
2192 }
2193
2194 if (isType(sitesym)) {
2195 if (sym.name == names._this) {
2196 // If `C' is the currently compiled class, check that
2197 // C.this' does not appear in a call to a super(...)
2198 if (env.info.isSelfCall &&
2199 site.tsym == env.enclClass.sym) {
2200 chk.earlyRefError(tree.pos(), sym);
2201 }
2202 } else {
2203 // Check if type-qualified fields or methods are static (JLS)
2204 if ((sym.flags() & STATIC) == 0 &&
2205 sym.name != names._super &&
2206 (sym.kind == VAR || sym.kind == MTH)) {
2207 rs.access(rs.new StaticError(sym),
2208 tree.pos(), site, sym.name, true);
2209 }
2210 }
2211 } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
2212 // If the qualified item is not a type and the selected item is static, report
2213 // a warning. Make allowance for the class of an array type e.g. Object[].class)
2214 chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
2215 }
2216
2217 // If we are selecting an instance member via a `super', ...
2218 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
2219
2220 // Check that super-qualified symbols are not abstract (JLS)
2221 rs.checkNonAbstract(tree.pos(), sym);
2222
2223 if (site.isRaw()) {
2224 // Determine argument types for site.
2225 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
2226 if (site1 != null) site = site1;
2227 }
2228 }
2229
2230 env.info.selectSuper = selectSuperPrev;
2231 result = checkId(tree, site, sym, env, pkind, pt, varArgs);
2232 env.info.tvars = List.nil();
2233 }
2234 //where
2235 /** Determine symbol referenced by a Select expression,
2236 *
2237 * @param tree The select tree.
2238 * @param site The type of the selected expression,
2239 * @param env The current environment.
2240 * @param pt The current prototype.
2241 * @param pkind The expected kind(s) of the Select expression.
2242 */
2243 private Symbol selectSym(JCFieldAccess tree,
2244 Type site,
2245 Env<AttrContext> env,
2246 Type pt,
2247 int pkind) {
2248 DiagnosticPosition pos = tree.pos();
2249 Name name = tree.name;
2250
2251 switch (site.tag) {
2252 case PACKAGE:
2253 return rs.access(
2254 rs.findIdentInPackage(env, site.tsym, name, pkind),
2255 pos, site, name, true);
2256 case ARRAY:
2257 case CLASS:
2258 if (pt.tag == METHOD || pt.tag == FORALL) {
2259 return rs.resolveQualifiedMethod(
2260 pos, env, site, name, pt.getParameterTypes(), pt.getTypeArguments());
2261 } else if (name == names._this || name == names._super) {
2262 return rs.resolveSelf(pos, env, site.tsym, name);
2263 } else if (name == names._class) {
2264 // In this case, we have already made sure in
2265 // visitSelect that qualifier expression is a type.
2266 Type t = syms.classType;
2267 List<Type> typeargs = allowGenerics
2268 ? List.of(types.erasure(site))
2269 : List.<Type>nil();
2270 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
2271 return new VarSymbol(
2272 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2273 } else {
2274 // We are seeing a plain identifier as selector.
2275 Symbol sym = rs.findIdentInType(env, site, name, pkind);
2276 if ((pkind & ERRONEOUS) == 0)
2277 sym = rs.access(sym, pos, site, name, true);
2278 return sym;
2279 }
2280 case WILDCARD:
2281 throw new AssertionError(tree);
2282 case TYPEVAR:
2283 // Normally, site.getUpperBound() shouldn't be null.
2284 // It should only happen during memberEnter/attribBase
2285 // when determining the super type which *must* be
2286 // done before attributing the type variables. In
2287 // other words, we are seeing this illegal program:
2288 // class B<T> extends A<T.foo> {}
2289 Symbol sym = (site.getUpperBound() != null)
2290 ? selectSym(tree, capture(site.getUpperBound()), env, pt, pkind)
2291 : null;
2292 if (sym == null) {
2293 log.error(pos, "type.var.cant.be.deref");
2294 return syms.errSymbol;
2295 } else {
2296 Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
2297 rs.new AccessError(env, site, sym) :
2298 sym;
2299 rs.access(sym2, pos, site, name, true);
2300 return sym;
2301 }
2302 case ERROR:
2303 // preserve identifier names through errors
2304 return types.createErrorType(name, site.tsym, site).tsym;
2305 default:
2306 // The qualifier expression is of a primitive type -- only
2307 // .class is allowed for these.
2308 if (name == names._class) {
2309 // In this case, we have already made sure in Select that
2310 // qualifier expression is a type.
2311 Type t = syms.classType;
2312 Type arg = types.boxedClass(site).type;
2313 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2314 return new VarSymbol(
2315 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2316 } else {
2317 log.error(pos, "cant.deref", site);
2318 return syms.errSymbol;
2319 }
2320 }
2321 }
2322
2323 /** Determine type of identifier or select expression and check that
2324 * (1) the referenced symbol is not deprecated
2325 * (2) the symbol's type is safe (@see checkSafe)
2326 * (3) if symbol is a variable, check that its type and kind are
2327 * compatible with the prototype and protokind.
2328 * (4) if symbol is an instance field of a raw type,
2329 * which is being assigned to, issue an unchecked warning if its
2330 * type changes under erasure.
2331 * (5) if symbol is an instance method of a raw type, issue an
2332 * unchecked warning if its argument types change under erasure.
2333 * If checks succeed:
2334 * If symbol is a constant, return its constant type
2335 * else if symbol is a method, return its result type
2336 * otherwise return its type.
2337 * Otherwise return errType.
2338 *
2339 * @param tree The syntax tree representing the identifier
2340 * @param site If this is a select, the type of the selected
2341 * expression, otherwise the type of the current class.
2342 * @param sym The symbol representing the identifier.
2343 * @param env The current environment.
2344 * @param pkind The set of expected kinds.
2345 * @param pt The expected type.
2346 */
2347 Type checkId(JCTree tree,
2348 Type site,
2349 Symbol sym,
2350 Env<AttrContext> env,
2351 int pkind,
2352 Type pt,
2353 boolean useVarargs) {
2354 if (pt.isErroneous()) return types.createErrorType(site);
2355 Type owntype; // The computed type of this identifier occurrence.
2356 switch (sym.kind) {
2357 case TYP:
2358 // For types, the computed type equals the symbol's type,
2359 // except for two situations:
2360 owntype = sym.type;
2361 if (owntype.tag == CLASS) {
2362 Type ownOuter = owntype.getEnclosingType();
2363
2364 // (a) If the symbol's type is parameterized, erase it
2365 // because no type parameters were given.
2366 // We recover generic outer type later in visitTypeApply.
2367 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2368 owntype = types.erasure(owntype);
2369 }
2370
2371 // (b) If the symbol's type is an inner class, then
2372 // we have to interpret its outer type as a superclass
2373 // of the site type. Example:
2374 //
2375 // class Tree<A> { class Visitor { ... } }
2376 // class PointTree extends Tree<Point> { ... }
2377 // ...PointTree.Visitor...
2378 //
2379 // Then the type of the last expression above is
2380 // Tree<Point>.Visitor.
2381 else if (ownOuter.tag == CLASS && site != ownOuter) {
2382 Type normOuter = site;
2383 if (normOuter.tag == CLASS)
2384 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2385 if (normOuter == null) // perhaps from an import
2386 normOuter = types.erasure(ownOuter);
2387 if (normOuter != ownOuter)
2388 owntype = new ClassType(
2389 normOuter, List.<Type>nil(), owntype.tsym);
2390 }
2391 }
2392 break;
2393 case VAR:
2394 VarSymbol v = (VarSymbol)sym;
2395 // Test (4): if symbol is an instance field of a raw type,
2396 // which is being assigned to, issue an unchecked warning if
2397 // its type changes under erasure.
2398 if (allowGenerics &&
2399 pkind == VAR &&
2400 v.owner.kind == TYP &&
2401 (v.flags() & STATIC) == 0 &&
2402 (site.tag == CLASS || site.tag == TYPEVAR)) {
2403 Type s = types.asOuterSuper(site, v.owner);
2404 if (s != null &&
2405 s.isRaw() &&
2406 !types.isSameType(v.type, v.erasure(types))) {
2407 chk.warnUnchecked(tree.pos(),
2408 "unchecked.assign.to.var",
2409 v, s);
2410 }
2411 }
2412 // The computed type of a variable is the type of the
2413 // variable symbol, taken as a member of the site type.
2414 owntype = (sym.owner.kind == TYP &&
2415 sym.name != names._this && sym.name != names._super)
2416 ? types.memberType(site, sym)
2417 : sym.type;
2418
2419 if (env.info.tvars.nonEmpty()) {
2420 Type owntype1 = new ForAll(env.info.tvars, owntype);
2421 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2422 if (!owntype.contains(l.head)) {
2423 log.error(tree.pos(), "undetermined.type", owntype1);
2424 owntype1 = types.createErrorType(owntype1);
2425 }
2426 owntype = owntype1;
2427 }
2428
2429 // If the variable is a constant, record constant value in
2430 // computed type.
2431 if (v.getConstValue() != null && isStaticReference(tree))
2432 owntype = owntype.constType(v.getConstValue());
2433
2434 if (pkind == VAL) {
2435 owntype = capture(owntype); // capture "names as expressions"
2436 }
2437 break;
2438 case MTH: {
2439 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2440 owntype = checkMethod(site, sym, env, app.args,
2441 pt.getParameterTypes(), pt.getTypeArguments(),
2442 env.info.varArgs);
2443 break;
2444 }
2445 case PCK: case ERR:
2446 owntype = sym.type;
2447 break;
2448 default:
2449 throw new AssertionError("unexpected kind: " + sym.kind +
2450 " in tree " + tree);
2451 }
2452
2453 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2454 // (for constructors, the error was given when the constructor was
2455 // resolved)
2456 if (sym.name != names.init &&
2457 (sym.flags() & DEPRECATED) != 0 &&
2458 (env.info.scope.owner.flags() & DEPRECATED) == 0 &&
2459 sym.outermostClass() != env.info.scope.owner.outermostClass())
2460 chk.warnDeprecated(tree.pos(), sym);
2461
2462 if ((sym.flags() & PROPRIETARY) != 0) {
2463 if (enableSunApiLintControl)
2464 chk.warnSunApi(tree.pos(), "sun.proprietary", sym);
2465 else
2466 log.strictWarning(tree.pos(), "sun.proprietary", sym);
2467 }
2468
2469 // Test (3): if symbol is a variable, check that its type and
2470 // kind are compatible with the prototype and protokind.
2471 return check(tree, owntype, sym.kind, pkind, pt);
2472 }
2473
2474 /** Check that variable is initialized and evaluate the variable's
2475 * initializer, if not yet done. Also check that variable is not
2476 * referenced before it is defined.
2477 * @param tree The tree making up the variable reference.
2478 * @param env The current environment.
2479 * @param v The variable's symbol.
2480 */
2481 private void checkInit(JCTree tree,
2482 Env<AttrContext> env,
2483 VarSymbol v,
2484 boolean onlyWarning) {
2485 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2486 // tree.pos + " " + v.pos + " " +
2487 // Resolve.isStatic(env));//DEBUG
2488
2489 // A forward reference is diagnosed if the declaration position
2490 // of the variable is greater than the current tree position
2491 // and the tree and variable definition occur in the same class
2492 // definition. Note that writes don't count as references.
2493 // This check applies only to class and instance
2494 // variables. Local variables follow different scope rules,
2495 // and are subject to definite assignment checking.
2496 if ((env.info.enclVar == v || v.pos > tree.pos) &&
2497 v.owner.kind == TYP &&
2498 canOwnInitializer(env.info.scope.owner) &&
2499 v.owner == env.info.scope.owner.enclClass() &&
2500 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2501 (env.tree.getTag() != JCTree.ASSIGN ||
2502 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2503 String suffix = (env.info.enclVar == v) ?
2504 "self.ref" : "forward.ref";
2505 if (!onlyWarning || isStaticEnumField(v)) {
2506 log.error(tree.pos(), "illegal." + suffix);
2507 } else if (useBeforeDeclarationWarning) {
2508 log.warning(tree.pos(), suffix, v);
2509 }
2510 }
2511
2512 v.getConstValue(); // ensure initializer is evaluated
2513
2514 checkEnumInitializer(tree, env, v);
2515 }
2516
2517 /**
2518 * Check for illegal references to static members of enum. In
2519 * an enum type, constructors and initializers may not
2520 * reference its static members unless they are constant.
2521 *
2522 * @param tree The tree making up the variable reference.
2523 * @param env The current environment.
2524 * @param v The variable's symbol.
2525 * @see JLS 3rd Ed. (8.9 Enums)
2526 */
2527 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2528 // JLS 3rd Ed.:
2529 //
2530 // "It is a compile-time error to reference a static field
2531 // of an enum type that is not a compile-time constant
2532 // (15.28) from constructors, instance initializer blocks,
2533 // or instance variable initializer expressions of that
2534 // type. It is a compile-time error for the constructors,
2535 // instance initializer blocks, or instance variable
2536 // initializer expressions of an enum constant e to refer
2537 // to itself or to an enum constant of the same type that
2538 // is declared to the right of e."
2539 if (isStaticEnumField(v)) {
2540 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2541
2542 if (enclClass == null || enclClass.owner == null)
2543 return;
2544
2545 // See if the enclosing class is the enum (or a
2546 // subclass thereof) declaring v. If not, this
2547 // reference is OK.
2548 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2549 return;
2550
2551 // If the reference isn't from an initializer, then
2552 // the reference is OK.
2553 if (!Resolve.isInitializer(env))
2554 return;
2555
2556 log.error(tree.pos(), "illegal.enum.static.ref");
2557 }
2558 }
2559
2560 /** Is the given symbol a static, non-constant field of an Enum?
2561 * Note: enum literals should not be regarded as such
2562 */
2563 private boolean isStaticEnumField(VarSymbol v) {
2564 return Flags.isEnum(v.owner) &&
2565 Flags.isStatic(v) &&
2566 !Flags.isConstant(v) &&
2567 v.name != names._class;
2568 }
2569
2570 /** Can the given symbol be the owner of code which forms part
2571 * if class initialization? This is the case if the symbol is
2572 * a type or field, or if the symbol is the synthetic method.
2573 * owning a block.
2574 */
2575 private boolean canOwnInitializer(Symbol sym) {
2576 return
2577 (sym.kind & (VAR | TYP)) != 0 ||
2578 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2579 }
2580
2581 Warner noteWarner = new Warner();
2582
2583 /**
2584 * Check that method arguments conform to its instantation.
2585 **/
2586 public Type checkMethod(Type site,
2587 Symbol sym,
2588 Env<AttrContext> env,
2589 final List<JCExpression> argtrees,
2590 List<Type> argtypes,
2591 List<Type> typeargtypes,
2592 boolean useVarargs) {
2593 // Test (5): if symbol is an instance method of a raw type, issue
2594 // an unchecked warning if its argument types change under erasure.
2595 if (allowGenerics &&
2596 (sym.flags() & STATIC) == 0 &&
2597 (site.tag == CLASS || site.tag == TYPEVAR)) {
2598 Type s = types.asOuterSuper(site, sym.owner);
2599 if (s != null && s.isRaw() &&
2600 !types.isSameTypes(sym.type.getParameterTypes(),
2601 sym.erasure(types).getParameterTypes())) {
2602 chk.warnUnchecked(env.tree.pos(),
2603 "unchecked.call.mbr.of.raw.type",
2604 sym, s);
2605 }
2606 }
2607
2608 // Compute the identifier's instantiated type.
2609 // For methods, we need to compute the instance type by
2610 // Resolve.instantiate from the symbol's type as well as
2611 // any type arguments and value arguments.
2612 noteWarner.warned = false;
2613 Type owntype = rs.instantiate(env,
2614 site,
2615 sym,
2616 argtypes,
2617 typeargtypes,
2618 true,
2619 useVarargs,
2620 noteWarner);
2621 boolean warned = noteWarner.warned;
2622
2623 // If this fails, something went wrong; we should not have
2624 // found the identifier in the first place.
2625 if (owntype == null) {
2626 if (!pt.isErroneous())
2627 log.error(env.tree.pos(),
2628 "internal.error.cant.instantiate",
2629 sym, site,
2630 Type.toString(pt.getParameterTypes()));
2631 owntype = types.createErrorType(site);
2632 } else {
2633 // System.out.println("call : " + env.tree);
2634 // System.out.println("method : " + owntype);
2635 // System.out.println("actuals: " + argtypes);
2636 List<Type> formals = owntype.getParameterTypes();
2637 Type last = useVarargs ? formals.last() : null;
2638 if (sym.name==names.init &&
2639 sym.owner == syms.enumSym)
2640 formals = formals.tail.tail;
2641 List<JCExpression> args = argtrees;
2642 while (formals.head != last) {
2643 JCTree arg = args.head;
2644 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2645 assertConvertible(arg, arg.type, formals.head, warn);
2646 warned |= warn.warned;
2647 args = args.tail;
2648 formals = formals.tail;
2649 }
2650 if (useVarargs) {
2651 Type varArg = types.elemtype(last);
2652 while (args.tail != null) {
2653 JCTree arg = args.head;
2654 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2655 assertConvertible(arg, arg.type, varArg, warn);
2656 warned |= warn.warned;
2657 args = args.tail;
2658 }
2659 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2660 // non-varargs call to varargs method
2661 Type varParam = owntype.getParameterTypes().last();
2662 Type lastArg = argtypes.last();
2663 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2664 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2665 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2666 types.elemtype(varParam),
2667 varParam);
2668 }
2669
2670 if (warned && sym.type.tag == FORALL) {
2671 chk.warnUnchecked(env.tree.pos(),
2672 "unchecked.meth.invocation.applied",
2673 kindName(sym),
2674 sym.name,
2675 rs.methodArguments(sym.type.getParameterTypes()),
2676 rs.methodArguments(argtypes),
2677 kindName(sym.location()),
2678 sym.location());
2679 owntype = new MethodType(owntype.getParameterTypes(),
2680 types.erasure(owntype.getReturnType()),
2681 owntype.getThrownTypes(),
2682 syms.methodClass);
2683 }
2684 if (useVarargs) {
2685 JCTree tree = env.tree;
2686 Type argtype = owntype.getParameterTypes().last();
2687 if (owntype.getReturnType().tag != FORALL || warned) {
2688 chk.checkVararg(env.tree.pos(), owntype.getParameterTypes(), sym, env);
2689 }
2690 Type elemtype = types.elemtype(argtype);
2691 switch (tree.getTag()) {
2692 case JCTree.APPLY:
2693 ((JCMethodInvocation) tree).varargsElement = elemtype;
2694 break;
2695 case JCTree.NEWCLASS:
2696 ((JCNewClass) tree).varargsElement = elemtype;
2697 break;
2698 default:
2699 throw new AssertionError(""+tree);
2700 }
2701 }
2702 }
2703 return owntype;
2704 }
2705
2706 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2707 if (types.isConvertible(actual, formal, warn))
2708 return;
2709
2710 if (formal.isCompound()
2711 && types.isSubtype(actual, types.supertype(formal))
2712 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2713 return;
2714
2715 if (false) {
2716 // TODO: make assertConvertible work
2717 chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal);
2718 throw new AssertionError("Tree: " + tree
2719 + " actual:" + actual
2720 + " formal: " + formal);
2721 }
2722 }
2723
2724 public void visitLiteral(JCLiteral tree) {
2725 result = check(
2726 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2727 }
2728 //where
2729 /** Return the type of a literal with given type tag.
2730 */
2731 Type litType(int tag) {
2732 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2733 }
2734
2735 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2736 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2737 }
2738
2739 public void visitTypeArray(JCArrayTypeTree tree) {
2740 Type etype = attribType(tree.elemtype, env);
2741 Type type = new ArrayType(etype, syms.arrayClass);
2742 result = check(tree, type, TYP, pkind, pt);
2743 }
2744
2745 /** Visitor method for parameterized types.
2746 * Bound checking is left until later, since types are attributed
2747 * before supertype structure is completely known
2748 */
2749 public void visitTypeApply(JCTypeApply tree) {
2750 Type owntype = types.createErrorType(tree.type);
2751
2752 // Attribute functor part of application and make sure it's a class.
2753 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2754
2755 // Attribute type parameters
2756 List<Type> actuals = attribTypes(tree.arguments, env);
2757
2758 if (clazztype.tag == CLASS) {
2759 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2760
2761 if (actuals.length() == formals.length() || actuals.length() == 0) {
2762 List<Type> a = actuals;
2763 List<Type> f = formals;
2764 while (a.nonEmpty()) {
2765 a.head = a.head.withTypeVar(f.head);
2766 a = a.tail;
2767 f = f.tail;
2768 }
2769 // Compute the proper generic outer
2770 Type clazzOuter = clazztype.getEnclosingType();
2771 if (clazzOuter.tag == CLASS) {
2772 Type site;
2773 JCExpression clazz = TreeInfo.typeIn(tree.clazz);
2774 if (clazz.getTag() == JCTree.IDENT) {
2775 site = env.enclClass.sym.type;
2776 } else if (clazz.getTag() == JCTree.SELECT) {
2777 site = ((JCFieldAccess) clazz).selected.type;
2778 } else throw new AssertionError(""+tree);
2779 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2780 if (site.tag == CLASS)
2781 site = types.asOuterSuper(site, clazzOuter.tsym);
2782 if (site == null)
2783 site = types.erasure(clazzOuter);
2784 clazzOuter = site;
2785 }
2786 }
2787 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2788 } else {
2789 if (formals.length() != 0) {
2790 log.error(tree.pos(), "wrong.number.type.args",
2791 Integer.toString(formals.length()));
2792 } else {
2793 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2794 }
2795 owntype = types.createErrorType(tree.type);
2796 }
2797 }
2798 result = check(tree, owntype, TYP, pkind, pt);
2799 }
2800
2801 public void visitTypeDisjoint(JCTypeDisjoint tree) {
2802 List<Type> componentTypes = attribTypes(tree.components, env);
2803 tree.type = result = check(tree, types.lub(componentTypes), TYP, pkind, pt);
2804 }
2805
2806 public void visitTypeParameter(JCTypeParameter tree) {
2807 TypeVar a = (TypeVar)tree.type;
2808 Set<Type> boundSet = new HashSet<Type>();
2809 if (a.bound.isErroneous())
2810 return;
2811 List<Type> bs = types.getBounds(a);
2812 if (tree.bounds.nonEmpty()) {
2813 // accept class or interface or typevar as first bound.
2814 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2815 boundSet.add(types.erasure(b));
2816 if (b.isErroneous()) {
2817 a.bound = b;
2818 }
2819 else if (b.tag == TYPEVAR) {
2820 // if first bound was a typevar, do not accept further bounds.
2821 if (tree.bounds.tail.nonEmpty()) {
2822 log.error(tree.bounds.tail.head.pos(),
2823 "type.var.may.not.be.followed.by.other.bounds");
2824 log.unrecoverableError = true;
2825 tree.bounds = List.of(tree.bounds.head);
2826 a.bound = bs.head;
2827 }
2828 } else {
2829 // if first bound was a class or interface, accept only interfaces
2830 // as further bounds.
2831 for (JCExpression bound : tree.bounds.tail) {
2832 bs = bs.tail;
2833 Type i = checkBase(bs.head, bound, env, false, true, false);
2834 if (i.isErroneous())
2835 a.bound = i;
2836 else if (i.tag == CLASS)
2837 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
2838 }
2839 }
2840 }
2841 bs = types.getBounds(a);
2842
2843 // in case of multiple bounds ...
2844 if (bs.length() > 1) {
2845 // ... the variable's bound is a class type flagged COMPOUND
2846 // (see comment for TypeVar.bound).
2847 // In this case, generate a class tree that represents the
2848 // bound class, ...
2849 JCTree extending;
2850 List<JCExpression> implementing;
2851 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
2852 extending = tree.bounds.head;
2853 implementing = tree.bounds.tail;
2854 } else {
2855 extending = null;
2856 implementing = tree.bounds;
2857 }
2858 JCClassDecl cd = make.at(tree.pos).ClassDef(
2859 make.Modifiers(PUBLIC | ABSTRACT),
2860 tree.name, List.<JCTypeParameter>nil(),
2861 extending, implementing, List.<JCTree>nil());
2862
2863 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
2864 assert (c.flags() & COMPOUND) != 0;
2865 cd.sym = c;
2866 c.sourcefile = env.toplevel.sourcefile;
2867
2868 // ... and attribute the bound class
2869 c.flags_field |= UNATTRIBUTED;
2870 Env<AttrContext> cenv = enter.classEnv(cd, env);
2871 enter.typeEnvs.put(c, cenv);
2872 }
2873 }
2874
2875
2876 public void visitWildcard(JCWildcard tree) {
2877 //- System.err.println("visitWildcard("+tree+");");//DEBUG
2878 Type type = (tree.kind.kind == BoundKind.UNBOUND)
2879 ? syms.objectType
2880 : attribType(tree.inner, env);
2881 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
2882 tree.kind.kind,
2883 syms.boundClass),
2884 TYP, pkind, pt);
2885 }
2886
2887 public void visitAnnotation(JCAnnotation tree) {
2888 log.error(tree.pos(), "annotation.not.valid.for.type", pt);
2889 result = tree.type = syms.errType;
2890 }
2891
2892 public void visitAnnotatedType(JCAnnotatedType tree) {
2893 result = tree.type = attribType(tree.getUnderlyingType(), env);
2894 }
2895
2896 public void visitErroneous(JCErroneous tree) {
2897 if (tree.errs != null)
2898 for (JCTree err : tree.errs)
2899 attribTree(err, env, ERR, pt);
2900 result = tree.type = syms.errType;
2901 }
2902
2903 /** Default visitor method for all other trees.
2904 */
2905 public void visitTree(JCTree tree) {
2906 throw new AssertionError();
2907 }
2908
2909 /** Main method: attribute class definition associated with given class symbol.
2910 * reporting completion failures at the given position.
2911 * @param pos The source position at which completion errors are to be
2912 * reported.
2913 * @param c The class symbol whose definition will be attributed.
2914 */
2915 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
2916 try {
2917 annotate.flush();
2918 attribClass(c);
2919 } catch (CompletionFailure ex) {
2920 chk.completionError(pos, ex);
2921 }
2922 }
2923
2924 /** Attribute class definition associated with given class symbol.
2925 * @param c The class symbol whose definition will be attributed.
2926 */
2927 void attribClass(ClassSymbol c) throws CompletionFailure {
2928 if (c.type.tag == ERROR) return;
2929
2930 // Check for cycles in the inheritance graph, which can arise from
2931 // ill-formed class files.
2932 chk.checkNonCyclic(null, c.type);
2933
2934 Type st = types.supertype(c.type);
2935 if ((c.flags_field & Flags.COMPOUND) == 0) {
2936 // First, attribute superclass.
2937 if (st.tag == CLASS)
2938 attribClass((ClassSymbol)st.tsym);
2939
2940 // Next attribute owner, if it is a class.
2941 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
2942 attribClass((ClassSymbol)c.owner);
2943 }
2944
2945 // The previous operations might have attributed the current class
2946 // if there was a cycle. So we test first whether the class is still
2947 // UNATTRIBUTED.
2948 if ((c.flags_field & UNATTRIBUTED) != 0) {
2949 c.flags_field &= ~UNATTRIBUTED;
2950
2951 // Get environment current at the point of class definition.
2952 Env<AttrContext> env = enter.typeEnvs.get(c);
2953
2954 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
2955 // because the annotations were not available at the time the env was created. Therefore,
2956 // we look up the environment chain for the first enclosing environment for which the
2957 // lint value is set. Typically, this is the parent env, but might be further if there
2958 // are any envs created as a result of TypeParameter nodes.
2959 Env<AttrContext> lintEnv = env;
2960 while (lintEnv.info.lint == null)
2961 lintEnv = lintEnv.next;
2962
2963 // Having found the enclosing lint value, we can initialize the lint value for this class
2964 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
2965
2966 Lint prevLint = chk.setLint(env.info.lint);
2967 JavaFileObject prev = log.useSource(c.sourcefile);
2968
2969 try {
2970 // java.lang.Enum may not be subclassed by a non-enum
2971 if (st.tsym == syms.enumSym &&
2972 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
2973 log.error(env.tree.pos(), "enum.no.subclassing");
2974
2975 // Enums may not be extended by source-level classes
2976 if (st.tsym != null &&
2977 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
2978 ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
2979 !target.compilerBootstrap(c)) {
2980 log.error(env.tree.pos(), "enum.types.not.extensible");
2981 }
2982 attribClassBody(env, c);
2983
2984 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
2985 } finally {
2986 log.useSource(prev);
2987 chk.setLint(prevLint);
2988 }
2989
2990 }
2991 }
2992
2993 public void visitImport(JCImport tree) {
2994 // nothing to do
2995 }
2996
2997 /** Finish the attribution of a class. */
2998 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
2999 JCClassDecl tree = (JCClassDecl)env.tree;
3000 assert c == tree.sym;
3001
3002 // Validate annotations
3003 chk.validateAnnotations(tree.mods.annotations, c);
3004
3005 // Validate type parameters, supertype and interfaces.
3006 attribBounds(tree.typarams);
3007 if (!c.isAnonymous()) {
3008 //already checked if anonymous
3009 chk.validate(tree.typarams, env);
3010 chk.validate(tree.extending, env);
3011 chk.validate(tree.implementing, env);
3012 }
3013
3014 // If this is a non-abstract class, check that it has no abstract
3015 // methods or unimplemented methods of an implemented interface.
3016 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
3017 if (!relax)
3018 chk.checkAllDefined(tree.pos(), c);
3019 }
3020
3021 if ((c.flags() & ANNOTATION) != 0) {
3022 if (tree.implementing.nonEmpty())
3023 log.error(tree.implementing.head.pos(),
3024 "cant.extend.intf.annotation");
3025 if (tree.typarams.nonEmpty())
3026 log.error(tree.typarams.head.pos(),
3027 "intf.annotation.cant.have.type.params");
3028 } else {
3029 // Check that all extended classes and interfaces
3030 // are compatible (i.e. no two define methods with same arguments
3031 // yet different return types). (JLS 8.4.6.3)
3032 chk.checkCompatibleSupertypes(tree.pos(), c.type);
3033 }
3034
3035 // Check that class does not import the same parameterized interface
3036 // with two different argument lists.
3037 chk.checkClassBounds(tree.pos(), c.type);
3038
3039 tree.type = c.type;
3040
3041 boolean assertsEnabled = false;
3042 assert assertsEnabled = true;
3043 if (assertsEnabled) {
3044 for (List<JCTypeParameter> l = tree.typarams;
3045 l.nonEmpty(); l = l.tail)
3046 assert env.info.scope.lookup(l.head.name).scope != null;
3047 }
3048
3049 // Check that a generic class doesn't extend Throwable
3050 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
3051 log.error(tree.extending.pos(), "generic.throwable");
3052
3053 // Check that all methods which implement some
3054 // method conform to the method they implement.
3055 chk.checkImplementations(tree);
3056
3057 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3058 // Attribute declaration
3059 attribStat(l.head, env);
3060 // Check that declarations in inner classes are not static (JLS 8.1.2)
3061 // Make an exception for static constants.
3062 if (c.owner.kind != PCK &&
3063 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
3064 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
3065 Symbol sym = null;
3066 if (l.head.getTag() == JCTree.VARDEF) sym = ((JCVariableDecl) l.head).sym;
3067 if (sym == null ||
3068 sym.kind != VAR ||
3069 ((VarSymbol) sym).getConstValue() == null)
3070 log.error(l.head.pos(), "icls.cant.have.static.decl");
3071 }
3072 }
3073
3074 // Check for cycles among non-initial constructors.
3075 chk.checkCyclicConstructors(tree);
3076
3077 // Check for cycles among annotation elements.
3078 chk.checkNonCyclicElements(tree);
3079
3080 // Check for proper use of serialVersionUID
3081 if (env.info.lint.isEnabled(Lint.LintCategory.SERIAL) &&
3082 isSerializable(c) &&
3083 (c.flags() & Flags.ENUM) == 0 &&
3084 (c.flags() & ABSTRACT) == 0) {
3085 checkSerialVersionUID(tree, c);
3086 }
3087
3088 // Check type annotations applicability rules
3089 validateTypeAnnotations(tree);
3090 }
3091 // where
3092 /** check if a class is a subtype of Serializable, if that is available. */
3093 private boolean isSerializable(ClassSymbol c) {
3094 try {
3095 syms.serializableType.complete();
3096 }
3097 catch (CompletionFailure e) {
3098 return false;
3099 }
3100 return types.isSubtype(c.type, syms.serializableType);
3101 }
3102
3103 /** Check that an appropriate serialVersionUID member is defined. */
3104 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
3105
3106 // check for presence of serialVersionUID
3107 Scope.Entry e = c.members().lookup(names.serialVersionUID);
3108 while (e.scope != null && e.sym.kind != VAR) e = e.next();
3109 if (e.scope == null) {
3110 log.warning(tree.pos(), "missing.SVUID", c);
3111 return;
3112 }
3113
3114 // check that it is static final
3115 VarSymbol svuid = (VarSymbol)e.sym;
3116 if ((svuid.flags() & (STATIC | FINAL)) !=
3117 (STATIC | FINAL))
3118 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
3119
3120 // check that it is long
3121 else if (svuid.type.tag != TypeTags.LONG)
3122 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
3123
3124 // check constant
3125 else if (svuid.getConstValue() == null)
3126 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
3127 }
3128
3129 private Type capture(Type type) {
3130 return types.capture(type);
3131 }
3132
3133 private void validateTypeAnnotations(JCTree tree) {
3134 tree.accept(typeAnnotationsValidator);
3135 }
3136 //where
3137 private final JCTree.Visitor typeAnnotationsValidator =
3138 new TreeScanner() {
3139 public void visitAnnotation(JCAnnotation tree) {
3140 if (tree instanceof JCTypeAnnotation) {
3141 chk.validateTypeAnnotation((JCTypeAnnotation)tree, false);
3142 }
3143 super.visitAnnotation(tree);
3144 }
3145 public void visitTypeParameter(JCTypeParameter tree) {
3146 chk.validateTypeAnnotations(tree.annotations, true);
3147 // don't call super. skip type annotations
3148 scan(tree.bounds);
3149 }
3150 public void visitMethodDef(JCMethodDecl tree) {
3151 // need to check static methods
3152 if ((tree.sym.flags() & Flags.STATIC) != 0) {
3153 for (JCTypeAnnotation a : tree.receiverAnnotations) {
3154 if (chk.isTypeAnnotation(a, false))
3155 log.error(a.pos(), "annotation.type.not.applicable");
3156 }
3157 }
3158 super.visitMethodDef(tree);
3159 }
3160 };
3161 }