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()) { //TWR resource
243 log.error(pos, "twr.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 boolean isTryWithResource = tree.resources.nonEmpty();
1001 // Create a nested environment for attributing the try block if needed
1002 Env<AttrContext> tryEnv = isTryWithResource ?
1003 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1004 localEnv;
1005 // Attribute resource declarations
1006 for (JCTree resource : tree.resources) {
1007 if (resource.getTag() == JCTree.VARDEF) {
1008 attribStat(resource, tryEnv);
1009 chk.checkType(resource, resource.type, syms.autoCloseableType, "twr.not.applicable.to.type");
1010 VarSymbol var = (VarSymbol)TreeInfo.symbolFor(resource);
1011 var.setData(ElementKind.RESOURCE_VARIABLE);
1012 } else {
1013 attribExpr(resource, tryEnv, syms.autoCloseableType, "twr.not.applicable.to.type");
1014 }
1015 }
1016 // Attribute body
1017 attribStat(tree.body, tryEnv);
1018 if (isTryWithResource)
1019 tryEnv.info.scope.leave();
1020
1021 // Attribute catch clauses
1022 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
1023 JCCatch c = l.head;
1024 Env<AttrContext> catchEnv =
1025 localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
1026 Type ctype = attribStat(c.param, catchEnv);
1027 if (TreeInfo.isMultiCatch(c)) {
1028 //check that multi-catch parameter is marked as final
1029 if ((c.param.sym.flags() & FINAL) == 0) {
1030 log.error(c.param.pos(), "multicatch.param.must.be.final", c.param.sym);
1031 }
1032 c.param.sym.flags_field = c.param.sym.flags() | DISJOINT;
1033 }
1034 if (c.param.type.tsym.kind == Kinds.VAR) {
1035 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
1036 }
1037 chk.checkType(c.param.vartype.pos(),
1038 chk.checkClassType(c.param.vartype.pos(), ctype),
1039 syms.throwableType);
1040 attribStat(c.body, catchEnv);
1041 catchEnv.info.scope.leave();
1042 }
1043
1044 // Attribute finalizer
1045 if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
1046
1047 localEnv.info.scope.leave();
1048 result = null;
1049 }
1050
1051 public void visitConditional(JCConditional tree) {
1052 attribExpr(tree.cond, env, syms.booleanType);
1053 attribExpr(tree.truepart, env);
1054 attribExpr(tree.falsepart, env);
1055 result = check(tree,
1056 capture(condType(tree.pos(), tree.cond.type,
1057 tree.truepart.type, tree.falsepart.type)),
1058 VAL, pkind, pt);
1059 }
1060 //where
1061 /** Compute the type of a conditional expression, after
1062 * checking that it exists. See Spec 15.25.
1063 *
1064 * @param pos The source position to be used for
1065 * error diagnostics.
1066 * @param condtype The type of the expression's condition.
1067 * @param thentype The type of the expression's then-part.
1068 * @param elsetype The type of the expression's else-part.
1069 */
1070 private Type condType(DiagnosticPosition pos,
1071 Type condtype,
1072 Type thentype,
1073 Type elsetype) {
1074 Type ctype = condType1(pos, condtype, thentype, elsetype);
1075
1076 // If condition and both arms are numeric constants,
1077 // evaluate at compile-time.
1078 return ((condtype.constValue() != null) &&
1079 (thentype.constValue() != null) &&
1080 (elsetype.constValue() != null))
1081 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
1082 : ctype;
1083 }
1084 /** Compute the type of a conditional expression, after
1085 * checking that it exists. Does not take into
1086 * account the special case where condition and both arms
1087 * are constants.
1088 *
1089 * @param pos The source position to be used for error
1090 * diagnostics.
1091 * @param condtype The type of the expression's condition.
1092 * @param thentype The type of the expression's then-part.
1093 * @param elsetype The type of the expression's else-part.
1094 */
1095 private Type condType1(DiagnosticPosition pos, Type condtype,
1096 Type thentype, Type elsetype) {
1097 // If same type, that is the result
1098 if (types.isSameType(thentype, elsetype))
1099 return thentype.baseType();
1100
1101 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1102 ? thentype : types.unboxedType(thentype);
1103 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1104 ? elsetype : types.unboxedType(elsetype);
1105
1106 // Otherwise, if both arms can be converted to a numeric
1107 // type, return the least numeric type that fits both arms
1108 // (i.e. return larger of the two, or return int if one
1109 // arm is short, the other is char).
1110 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1111 // If one arm has an integer subrange type (i.e., byte,
1112 // short, or char), and the other is an integer constant
1113 // that fits into the subrange, return the subrange type.
1114 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1115 types.isAssignable(elseUnboxed, thenUnboxed))
1116 return thenUnboxed.baseType();
1117 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1118 types.isAssignable(thenUnboxed, elseUnboxed))
1119 return elseUnboxed.baseType();
1120
1121 for (int i = BYTE; i < VOID; i++) {
1122 Type candidate = syms.typeOfTag[i];
1123 if (types.isSubtype(thenUnboxed, candidate) &&
1124 types.isSubtype(elseUnboxed, candidate))
1125 return candidate;
1126 }
1127 }
1128
1129 // Those were all the cases that could result in a primitive
1130 if (allowBoxing) {
1131 if (thentype.isPrimitive())
1132 thentype = types.boxedClass(thentype).type;
1133 if (elsetype.isPrimitive())
1134 elsetype = types.boxedClass(elsetype).type;
1135 }
1136
1137 if (types.isSubtype(thentype, elsetype))
1138 return elsetype.baseType();
1139 if (types.isSubtype(elsetype, thentype))
1140 return thentype.baseType();
1141
1142 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1143 log.error(pos, "neither.conditional.subtype",
1144 thentype, elsetype);
1145 return thentype.baseType();
1146 }
1147
1148 // both are known to be reference types. The result is
1149 // lub(thentype,elsetype). This cannot fail, as it will
1150 // always be possible to infer "Object" if nothing better.
1151 return types.lub(thentype.baseType(), elsetype.baseType());
1152 }
1153
1154 public void visitIf(JCIf tree) {
1155 attribExpr(tree.cond, env, syms.booleanType);
1156 attribStat(tree.thenpart, env);
1157 if (tree.elsepart != null)
1158 attribStat(tree.elsepart, env);
1159 chk.checkEmptyIf(tree);
1160 result = null;
1161 }
1162
1163 public void visitExec(JCExpressionStatement tree) {
1164 attribExpr(tree.expr, env);
1165 result = null;
1166 }
1167
1168 public void visitBreak(JCBreak tree) {
1169 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1170 result = null;
1171 }
1172
1173 public void visitContinue(JCContinue tree) {
1174 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1175 result = null;
1176 }
1177 //where
1178 /** Return the target of a break or continue statement, if it exists,
1179 * report an error if not.
1180 * Note: The target of a labelled break or continue is the
1181 * (non-labelled) statement tree referred to by the label,
1182 * not the tree representing the labelled statement itself.
1183 *
1184 * @param pos The position to be used for error diagnostics
1185 * @param tag The tag of the jump statement. This is either
1186 * Tree.BREAK or Tree.CONTINUE.
1187 * @param label The label of the jump statement, or null if no
1188 * label is given.
1189 * @param env The environment current at the jump statement.
1190 */
1191 private JCTree findJumpTarget(DiagnosticPosition pos,
1192 int tag,
1193 Name label,
1194 Env<AttrContext> env) {
1195 // Search environments outwards from the point of jump.
1196 Env<AttrContext> env1 = env;
1197 LOOP:
1198 while (env1 != null) {
1199 switch (env1.tree.getTag()) {
1200 case JCTree.LABELLED:
1201 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1202 if (label == labelled.label) {
1203 // If jump is a continue, check that target is a loop.
1204 if (tag == JCTree.CONTINUE) {
1205 if (labelled.body.getTag() != JCTree.DOLOOP &&
1206 labelled.body.getTag() != JCTree.WHILELOOP &&
1207 labelled.body.getTag() != JCTree.FORLOOP &&
1208 labelled.body.getTag() != JCTree.FOREACHLOOP)
1209 log.error(pos, "not.loop.label", label);
1210 // Found labelled statement target, now go inwards
1211 // to next non-labelled tree.
1212 return TreeInfo.referencedStatement(labelled);
1213 } else {
1214 return labelled;
1215 }
1216 }
1217 break;
1218 case JCTree.DOLOOP:
1219 case JCTree.WHILELOOP:
1220 case JCTree.FORLOOP:
1221 case JCTree.FOREACHLOOP:
1222 if (label == null) return env1.tree;
1223 break;
1224 case JCTree.SWITCH:
1225 if (label == null && tag == JCTree.BREAK) return env1.tree;
1226 break;
1227 case JCTree.METHODDEF:
1228 case JCTree.CLASSDEF:
1229 break LOOP;
1230 default:
1231 }
1232 env1 = env1.next;
1233 }
1234 if (label != null)
1235 log.error(pos, "undef.label", label);
1236 else if (tag == JCTree.CONTINUE)
1237 log.error(pos, "cont.outside.loop");
1238 else
1239 log.error(pos, "break.outside.switch.loop");
1240 return null;
1241 }
1242
1243 public void visitReturn(JCReturn tree) {
1244 // Check that there is an enclosing method which is
1245 // nested within than the enclosing class.
1246 if (env.enclMethod == null ||
1247 env.enclMethod.sym.owner != env.enclClass.sym) {
1248 log.error(tree.pos(), "ret.outside.meth");
1249
1250 } else {
1251 // Attribute return expression, if it exists, and check that
1252 // it conforms to result type of enclosing method.
1253 Symbol m = env.enclMethod.sym;
1254 if (m.type.getReturnType().tag == VOID) {
1255 if (tree.expr != null)
1256 log.error(tree.expr.pos(),
1257 "cant.ret.val.from.meth.decl.void");
1258 } else if (tree.expr == null) {
1259 log.error(tree.pos(), "missing.ret.val");
1260 } else {
1261 attribExpr(tree.expr, env, m.type.getReturnType());
1262 }
1263 }
1264 result = null;
1265 }
1266
1267 public void visitThrow(JCThrow tree) {
1268 attribExpr(tree.expr, env, syms.throwableType);
1269 result = null;
1270 }
1271
1272 public void visitAssert(JCAssert tree) {
1273 attribExpr(tree.cond, env, syms.booleanType);
1274 if (tree.detail != null) {
1275 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1276 }
1277 result = null;
1278 }
1279
1280 /** Visitor method for method invocations.
1281 * NOTE: The method part of an application will have in its type field
1282 * the return type of the method, not the method's type itself!
1283 */
1284 public void visitApply(JCMethodInvocation tree) {
1285 // The local environment of a method application is
1286 // a new environment nested in the current one.
1287 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1288
1289 // The types of the actual method arguments.
1290 List<Type> argtypes;
1291
1292 // The types of the actual method type arguments.
1293 List<Type> typeargtypes = null;
1294 boolean typeargtypesNonRefOK = false;
1295
1296 Name methName = TreeInfo.name(tree.meth);
1297
1298 boolean isConstructorCall =
1299 methName == names._this || methName == names._super;
1300
1301 if (isConstructorCall) {
1302 // We are seeing a ...this(...) or ...super(...) call.
1303 // Check that this is the first statement in a constructor.
1304 if (checkFirstConstructorStat(tree, env)) {
1305
1306 // Record the fact
1307 // that this is a constructor call (using isSelfCall).
1308 localEnv.info.isSelfCall = true;
1309
1310 // Attribute arguments, yielding list of argument types.
1311 argtypes = attribArgs(tree.args, localEnv);
1312 typeargtypes = attribTypes(tree.typeargs, localEnv);
1313
1314 // Variable `site' points to the class in which the called
1315 // constructor is defined.
1316 Type site = env.enclClass.sym.type;
1317 if (methName == names._super) {
1318 if (site == syms.objectType) {
1319 log.error(tree.meth.pos(), "no.superclass", site);
1320 site = types.createErrorType(syms.objectType);
1321 } else {
1322 site = types.supertype(site);
1323 }
1324 }
1325
1326 if (site.tag == CLASS) {
1327 Type encl = site.getEnclosingType();
1328 while (encl != null && encl.tag == TYPEVAR)
1329 encl = encl.getUpperBound();
1330 if (encl.tag == CLASS) {
1331 // we are calling a nested class
1332
1333 if (tree.meth.getTag() == JCTree.SELECT) {
1334 JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1335
1336 // We are seeing a prefixed call, of the form
1337 // <expr>.super(...).
1338 // Check that the prefix expression conforms
1339 // to the outer instance type of the class.
1340 chk.checkRefType(qualifier.pos(),
1341 attribExpr(qualifier, localEnv,
1342 encl));
1343 } else if (methName == names._super) {
1344 // qualifier omitted; check for existence
1345 // of an appropriate implicit qualifier.
1346 rs.resolveImplicitThis(tree.meth.pos(),
1347 localEnv, site);
1348 }
1349 } else if (tree.meth.getTag() == JCTree.SELECT) {
1350 log.error(tree.meth.pos(), "illegal.qual.not.icls",
1351 site.tsym);
1352 }
1353
1354 // if we're calling a java.lang.Enum constructor,
1355 // prefix the implicit String and int parameters
1356 if (site.tsym == syms.enumSym && allowEnums)
1357 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1358
1359 // Resolve the called constructor under the assumption
1360 // that we are referring to a superclass instance of the
1361 // current instance (JLS ???).
1362 boolean selectSuperPrev = localEnv.info.selectSuper;
1363 localEnv.info.selectSuper = true;
1364 localEnv.info.varArgs = false;
1365 Symbol sym = rs.resolveConstructor(
1366 tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1367 localEnv.info.selectSuper = selectSuperPrev;
1368
1369 // Set method symbol to resolved constructor...
1370 TreeInfo.setSymbol(tree.meth, sym);
1371
1372 // ...and check that it is legal in the current context.
1373 // (this will also set the tree's type)
1374 Type mpt = newMethTemplate(argtypes, typeargtypes);
1375 checkId(tree.meth, site, sym, localEnv, MTH,
1376 mpt, tree.varargsElement != null);
1377 }
1378 // Otherwise, `site' is an error type and we do nothing
1379 }
1380 result = tree.type = syms.voidType;
1381 } else {
1382 // Otherwise, we are seeing a regular method call.
1383 // Attribute the arguments, yielding list of argument types, ...
1384 argtypes = attribArgs(tree.args, localEnv);
1385 typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
1386
1387 // ... and attribute the method using as a prototype a methodtype
1388 // whose formal argument types is exactly the list of actual
1389 // arguments (this will also set the method symbol).
1390 Type mpt = newMethTemplate(argtypes, typeargtypes);
1391 localEnv.info.varArgs = false;
1392 Type mtype = attribExpr(tree.meth, localEnv, mpt);
1393 if (localEnv.info.varArgs)
1394 assert mtype.isErroneous() || tree.varargsElement != null;
1395
1396 // Compute the result type.
1397 Type restype = mtype.getReturnType();
1398 assert restype.tag != WILDCARD : mtype;
1399
1400 // as a special case, array.clone() has a result that is
1401 // the same as static type of the array being cloned
1402 if (tree.meth.getTag() == JCTree.SELECT &&
1403 allowCovariantReturns &&
1404 methName == names.clone &&
1405 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1406 restype = ((JCFieldAccess) tree.meth).selected.type;
1407
1408 // as a special case, x.getClass() has type Class<? extends |X|>
1409 if (allowGenerics &&
1410 methName == names.getClass && tree.args.isEmpty()) {
1411 Type qualifier = (tree.meth.getTag() == JCTree.SELECT)
1412 ? ((JCFieldAccess) tree.meth).selected.type
1413 : env.enclClass.sym.type;
1414 restype = new
1415 ClassType(restype.getEnclosingType(),
1416 List.<Type>of(new WildcardType(types.erasure(qualifier),
1417 BoundKind.EXTENDS,
1418 syms.boundClass)),
1419 restype.tsym);
1420 }
1421
1422 // as a special case, MethodHandle.<T>invoke(abc) and InvokeDynamic.<T>foo(abc)
1423 // has type <T>, and T can be a primitive type.
1424 if (tree.meth.getTag() == JCTree.SELECT && !typeargtypes.isEmpty()) {
1425 JCFieldAccess mfield = (JCFieldAccess) tree.meth;
1426 if ((mfield.selected.type.tsym != null &&
1427 (mfield.selected.type.tsym.flags() & POLYMORPHIC_SIGNATURE) != 0)
1428 ||
1429 (mfield.sym != null &&
1430 (mfield.sym.flags() & POLYMORPHIC_SIGNATURE) != 0)) {
1431 assert types.isSameType(restype, typeargtypes.head) : mtype;
1432 assert mfield.selected.type == syms.methodHandleType
1433 || mfield.selected.type == syms.invokeDynamicType;
1434 typeargtypesNonRefOK = true;
1435 }
1436 }
1437
1438 if (!typeargtypesNonRefOK) {
1439 chk.checkRefTypes(tree.typeargs, typeargtypes);
1440 }
1441
1442 // Check that value of resulting type is admissible in the
1443 // current context. Also, capture the return type
1444 result = check(tree, capture(restype), VAL, pkind, pt);
1445 }
1446 chk.validate(tree.typeargs, localEnv);
1447 }
1448 //where
1449 /** Check that given application node appears as first statement
1450 * in a constructor call.
1451 * @param tree The application node
1452 * @param env The environment current at the application.
1453 */
1454 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1455 JCMethodDecl enclMethod = env.enclMethod;
1456 if (enclMethod != null && enclMethod.name == names.init) {
1457 JCBlock body = enclMethod.body;
1458 if (body.stats.head.getTag() == JCTree.EXEC &&
1459 ((JCExpressionStatement) body.stats.head).expr == tree)
1460 return true;
1461 }
1462 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1463 TreeInfo.name(tree.meth));
1464 return false;
1465 }
1466
1467 /** Obtain a method type with given argument types.
1468 */
1469 Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
1470 MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
1471 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1472 }
1473
1474 public void visitNewClass(JCNewClass tree) {
1475 Type owntype = types.createErrorType(tree.type);
1476
1477 // The local environment of a class creation is
1478 // a new environment nested in the current one.
1479 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1480
1481 // The anonymous inner class definition of the new expression,
1482 // if one is defined by it.
1483 JCClassDecl cdef = tree.def;
1484
1485 // If enclosing class is given, attribute it, and
1486 // complete class name to be fully qualified
1487 JCExpression clazz = tree.clazz; // Class field following new
1488 JCExpression clazzid = // Identifier in class field
1489 (clazz.getTag() == JCTree.TYPEAPPLY)
1490 ? ((JCTypeApply) clazz).clazz
1491 : clazz;
1492
1493 JCExpression clazzid1 = clazzid; // The same in fully qualified form
1494
1495 if (tree.encl != null) {
1496 // We are seeing a qualified new, of the form
1497 // <expr>.new C <...> (...) ...
1498 // In this case, we let clazz stand for the name of the
1499 // allocated class C prefixed with the type of the qualifier
1500 // expression, so that we can
1501 // resolve it with standard techniques later. I.e., if
1502 // <expr> has type T, then <expr>.new C <...> (...)
1503 // yields a clazz T.C.
1504 Type encltype = chk.checkRefType(tree.encl.pos(),
1505 attribExpr(tree.encl, env));
1506 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1507 ((JCIdent) clazzid).name);
1508 if (clazz.getTag() == JCTree.TYPEAPPLY)
1509 clazz = make.at(tree.pos).
1510 TypeApply(clazzid1,
1511 ((JCTypeApply) clazz).arguments);
1512 else
1513 clazz = clazzid1;
1514 }
1515
1516 // Attribute clazz expression and store
1517 // symbol + type back into the attributed tree.
1518 Type clazztype = attribType(clazz, env);
1519 Pair<Scope,Scope> mapping = getSyntheticScopeMapping(clazztype);
1520 if (!TreeInfo.isDiamond(tree)) {
1521 clazztype = chk.checkClassType(
1522 tree.clazz.pos(), clazztype, true);
1523 }
1524 chk.validate(clazz, localEnv);
1525 if (tree.encl != null) {
1526 // We have to work in this case to store
1527 // symbol + type back into the attributed tree.
1528 tree.clazz.type = clazztype;
1529 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1530 clazzid.type = ((JCIdent) clazzid).sym.type;
1531 if (!clazztype.isErroneous()) {
1532 if (cdef != null && clazztype.tsym.isInterface()) {
1533 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1534 } else if (clazztype.tsym.isStatic()) {
1535 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1536 }
1537 }
1538 } else if (!clazztype.tsym.isInterface() &&
1539 clazztype.getEnclosingType().tag == CLASS) {
1540 // Check for the existence of an apropos outer instance
1541 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1542 }
1543
1544 // Attribute constructor arguments.
1545 List<Type> argtypes = attribArgs(tree.args, localEnv);
1546 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1547
1548 if (TreeInfo.isDiamond(tree)) {
1549 clazztype = attribDiamond(localEnv, tree, clazztype, mapping, argtypes, typeargtypes, true);
1550 clazz.type = clazztype;
1551 }
1552
1553 // If we have made no mistakes in the class type...
1554 if (clazztype.tag == CLASS) {
1555 // Enums may not be instantiated except implicitly
1556 if (allowEnums &&
1557 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1558 (env.tree.getTag() != JCTree.VARDEF ||
1559 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1560 ((JCVariableDecl) env.tree).init != tree))
1561 log.error(tree.pos(), "enum.cant.be.instantiated");
1562 // Check that class is not abstract
1563 if (cdef == null &&
1564 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1565 log.error(tree.pos(), "abstract.cant.be.instantiated",
1566 clazztype.tsym);
1567 } else if (cdef != null && clazztype.tsym.isInterface()) {
1568 // Check that no constructor arguments are given to
1569 // anonymous classes implementing an interface
1570 if (!argtypes.isEmpty())
1571 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1572
1573 if (!typeargtypes.isEmpty())
1574 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1575
1576 // Error recovery: pretend no arguments were supplied.
1577 argtypes = List.nil();
1578 typeargtypes = List.nil();
1579 }
1580
1581 // Resolve the called constructor under the assumption
1582 // that we are referring to a superclass instance of the
1583 // current instance (JLS ???).
1584 else {
1585 localEnv.info.selectSuper = cdef != null;
1586 localEnv.info.varArgs = false;
1587 tree.constructor = rs.resolveConstructor(
1588 tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
1589 tree.constructorType = checkMethod(clazztype,
1590 tree.constructor,
1591 localEnv,
1592 tree.args,
1593 argtypes,
1594 typeargtypes,
1595 localEnv.info.varArgs);
1596 if (localEnv.info.varArgs)
1597 assert tree.constructorType.isErroneous() || tree.varargsElement != null;
1598 }
1599
1600 if (cdef != null) {
1601 // We are seeing an anonymous class instance creation.
1602 // In this case, the class instance creation
1603 // expression
1604 //
1605 // E.new <typeargs1>C<typargs2>(args) { ... }
1606 //
1607 // is represented internally as
1608 //
1609 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1610 //
1611 // This expression is then *transformed* as follows:
1612 //
1613 // (1) add a STATIC flag to the class definition
1614 // if the current environment is static
1615 // (2) add an extends or implements clause
1616 // (3) add a constructor.
1617 //
1618 // For instance, if C is a class, and ET is the type of E,
1619 // the expression
1620 //
1621 // E.new <typeargs1>C<typargs2>(args) { ... }
1622 //
1623 // is translated to (where X is a fresh name and typarams is the
1624 // parameter list of the super constructor):
1625 //
1626 // new <typeargs1>X(<*nullchk*>E, args) where
1627 // X extends C<typargs2> {
1628 // <typarams> X(ET e, args) {
1629 // e.<typeargs1>super(args)
1630 // }
1631 // ...
1632 // }
1633 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1634
1635 if (clazztype.tsym.isInterface()) {
1636 cdef.implementing = List.of(clazz);
1637 } else {
1638 cdef.extending = clazz;
1639 }
1640
1641 attribStat(cdef, localEnv);
1642
1643 // If an outer instance is given,
1644 // prefix it to the constructor arguments
1645 // and delete it from the new expression
1646 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1647 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1648 argtypes = argtypes.prepend(tree.encl.type);
1649 tree.encl = null;
1650 }
1651
1652 // Reassign clazztype and recompute constructor.
1653 clazztype = cdef.sym.type;
1654 Symbol sym = rs.resolveConstructor(
1655 tree.pos(), localEnv, clazztype, argtypes,
1656 typeargtypes, true, tree.varargsElement != null);
1657 assert sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous();
1658 tree.constructor = sym;
1659 if (tree.constructor.kind > ERRONEOUS) {
1660 tree.constructorType = syms.errType;
1661 }
1662 else {
1663 tree.constructorType = checkMethod(clazztype,
1664 tree.constructor,
1665 localEnv,
1666 tree.args,
1667 argtypes,
1668 typeargtypes,
1669 localEnv.info.varArgs);
1670 }
1671 }
1672
1673 if (tree.constructor != null && tree.constructor.kind == MTH)
1674 owntype = clazztype;
1675 }
1676 result = check(tree, owntype, VAL, pkind, pt);
1677 chk.validate(tree.typeargs, localEnv);
1678 }
1679
1680 Type attribDiamond(Env<AttrContext> env,
1681 JCNewClass tree,
1682 Type clazztype,
1683 Pair<Scope, Scope> mapping,
1684 List<Type> argtypes,
1685 List<Type> typeargtypes,
1686 boolean reportErrors) {
1687 if (clazztype.isErroneous() || mapping == erroneousMapping) {
1688 //if the type of the instance creation expression is erroneous,
1689 //or something prevented us to form a valid mapping, return the
1690 //(possibly erroneous) type unchanged
1691 return clazztype;
1692 }
1693 else if (clazztype.isInterface()) {
1694 //if the type of the instance creation expression is an interface
1695 //skip the method resolution step (JLS 15.12.2.7). The type to be
1696 //inferred is of the kind <X1,X2, ... Xn>C<X1,X2, ... Xn>
1697 clazztype = new ForAll(clazztype.tsym.type.allparams(),
1698 clazztype.tsym.type);
1699 } else {
1700 //if the type of the instance creation expression is a class type
1701 //apply method resolution inference (JLS 15.12.2.7). The return type
1702 //of the resolved constructor will be a partially instantiated type
1703 ((ClassSymbol) clazztype.tsym).members_field = mapping.snd;
1704 Symbol constructor;
1705 try {
1706 constructor = rs.resolveDiamond(tree.pos(),
1707 env,
1708 clazztype.tsym.type,
1709 argtypes,
1710 typeargtypes, reportErrors);
1711 } finally {
1712 ((ClassSymbol) clazztype.tsym).members_field = mapping.fst;
1713 }
1714 if (constructor.kind == MTH) {
1715 ClassType ct = new ClassType(clazztype.getEnclosingType(),
1716 clazztype.tsym.type.getTypeArguments(),
1717 clazztype.tsym);
1718 clazztype = checkMethod(ct,
1719 constructor,
1720 env,
1721 tree.args,
1722 argtypes,
1723 typeargtypes,
1724 env.info.varArgs).getReturnType();
1725 } else {
1726 clazztype = syms.errType;
1727 }
1728 }
1729 if (clazztype.tag == FORALL && !pt.isErroneous()) {
1730 //if the resolved constructor's return type has some uninferred
1731 //type-variables, infer them using the expected type and declared
1732 //bounds (JLS 15.12.2.8).
1733 try {
1734 clazztype = infer.instantiateExpr((ForAll) clazztype,
1735 pt.tag == NONE ? syms.objectType : pt,
1736 Warner.noWarnings);
1737 } catch (Infer.InferenceException ex) {
1738 //an error occurred while inferring uninstantiated type-variables
1739 //we need to optionally report an error
1740 if (reportErrors) {
1741 log.error(tree.clazz.pos(),
1742 "cant.apply.diamond.1",
1743 diags.fragment("diamond", clazztype.tsym),
1744 ex.diagnostic);
1745 }
1746 }
1747 }
1748 if (reportErrors) {
1749 clazztype = chk.checkClassType(tree.clazz.pos(),
1750 clazztype,
1751 true);
1752 if (clazztype.tag == CLASS) {
1753 List<Type> invalidDiamondArgs = chk.checkDiamond((ClassType)clazztype);
1754 if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
1755 //one or more types inferred in the previous steps is either a
1756 //captured type or an intersection type --- we need to report an error.
1757 String subkey = invalidDiamondArgs.size() > 1 ?
1758 "diamond.invalid.args" :
1759 "diamond.invalid.arg";
1760 //The error message is of the kind:
1761 //
1762 //cannot infer type arguments for {clazztype}<>;
1763 //reason: {subkey}
1764 //
1765 //where subkey is a fragment of the kind:
1766 //
1767 //type argument(s) {invalidDiamondArgs} inferred for {clazztype}<> is not allowed in this context
1768 log.error(tree.clazz.pos(),
1769 "cant.apply.diamond.1",
1770 diags.fragment("diamond", clazztype.tsym),
1771 diags.fragment(subkey,
1772 invalidDiamondArgs,
1773 diags.fragment("diamond", clazztype.tsym)));
1774 }
1775 }
1776 }
1777 return clazztype;
1778 }
1779
1780 /** Creates a synthetic scope containing fake generic constructors.
1781 * Assuming that the original scope contains a constructor of the kind:
1782 * Foo(X x, Y y), where X,Y are class type-variables declared in Foo,
1783 * the synthetic scope is added a generic constructor of the kind:
1784 * <X,Y>Foo<X,Y>(X x, Y y). This is crucial in order to enable diamond
1785 * inference. The inferred return type of the synthetic constructor IS
1786 * the inferred type for the diamond operator.
1787 */
1788 private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype) {
1789 if (ctype.tag != CLASS) {
1790 return erroneousMapping;
1791 }
1792 Pair<Scope, Scope> mapping =
1793 new Pair<Scope, Scope>(ctype.tsym.members(), new Scope(ctype.tsym));
1794 List<Type> typevars = ctype.tsym.type.getTypeArguments();
1795 for (Scope.Entry e = mapping.fst.lookup(names.init);
1796 e.scope != null;
1797 e = e.next()) {
1798 MethodSymbol newConstr = (MethodSymbol) e.sym.clone(ctype.tsym);
1799 newConstr.name = names.init;
1800 List<Type> oldTypeargs = List.nil();
1801 if (newConstr.type.tag == FORALL) {
1802 oldTypeargs = ((ForAll) newConstr.type).tvars;
1803 }
1804 newConstr.type = new MethodType(newConstr.type.getParameterTypes(),
1805 new ClassType(ctype.getEnclosingType(), ctype.tsym.type.getTypeArguments(), ctype.tsym),
1806 newConstr.type.getThrownTypes(),
1807 syms.methodClass);
1808 newConstr.type = new ForAll(typevars.prependList(oldTypeargs), newConstr.type);
1809 mapping.snd.enter(newConstr);
1810 }
1811 return mapping;
1812 }
1813
1814 private final Pair<Scope,Scope> erroneousMapping = new Pair<Scope,Scope>(null, null);
1815
1816 /** Make an attributed null check tree.
1817 */
1818 public JCExpression makeNullCheck(JCExpression arg) {
1819 // optimization: X.this is never null; skip null check
1820 Name name = TreeInfo.name(arg);
1821 if (name == names._this || name == names._super) return arg;
1822
1823 int optag = JCTree.NULLCHK;
1824 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1825 tree.operator = syms.nullcheck;
1826 tree.type = arg.type;
1827 return tree;
1828 }
1829
1830 public void visitNewArray(JCNewArray tree) {
1831 Type owntype = types.createErrorType(tree.type);
1832 Type elemtype;
1833 if (tree.elemtype != null) {
1834 elemtype = attribType(tree.elemtype, env);
1835 chk.validate(tree.elemtype, env);
1836 owntype = elemtype;
1837 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1838 attribExpr(l.head, env, syms.intType);
1839 owntype = new ArrayType(owntype, syms.arrayClass);
1840 }
1841 } else {
1842 // we are seeing an untyped aggregate { ... }
1843 // this is allowed only if the prototype is an array
1844 if (pt.tag == ARRAY) {
1845 elemtype = types.elemtype(pt);
1846 } else {
1847 if (pt.tag != ERROR) {
1848 log.error(tree.pos(), "illegal.initializer.for.type",
1849 pt);
1850 }
1851 elemtype = types.createErrorType(pt);
1852 }
1853 }
1854 if (tree.elems != null) {
1855 attribExprs(tree.elems, env, elemtype);
1856 owntype = new ArrayType(elemtype, syms.arrayClass);
1857 }
1858 if (!types.isReifiable(elemtype))
1859 log.error(tree.pos(), "generic.array.creation");
1860 result = check(tree, owntype, VAL, pkind, pt);
1861 }
1862
1863 public void visitParens(JCParens tree) {
1864 Type owntype = attribTree(tree.expr, env, pkind, pt);
1865 result = check(tree, owntype, pkind, pkind, pt);
1866 Symbol sym = TreeInfo.symbol(tree);
1867 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1868 log.error(tree.pos(), "illegal.start.of.type");
1869 }
1870
1871 public void visitAssign(JCAssign tree) {
1872 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1873 Type capturedType = capture(owntype);
1874 attribExpr(tree.rhs, env, owntype);
1875 result = check(tree, capturedType, VAL, pkind, pt);
1876 }
1877
1878 public void visitAssignop(JCAssignOp tree) {
1879 // Attribute arguments.
1880 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
1881 Type operand = attribExpr(tree.rhs, env);
1882 // Find operator.
1883 Symbol operator = tree.operator = rs.resolveBinaryOperator(
1884 tree.pos(), tree.getTag() - JCTree.ASGOffset, env,
1885 owntype, operand);
1886
1887 if (operator.kind == MTH) {
1888 chk.checkOperator(tree.pos(),
1889 (OperatorSymbol)operator,
1890 tree.getTag() - JCTree.ASGOffset,
1891 owntype,
1892 operand);
1893 chk.checkDivZero(tree.rhs.pos(), operator, operand);
1894 chk.checkCastable(tree.rhs.pos(),
1895 operator.type.getReturnType(),
1896 owntype);
1897 }
1898 result = check(tree, owntype, VAL, pkind, pt);
1899 }
1900
1901 public void visitUnary(JCUnary tree) {
1902 // Attribute arguments.
1903 Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1904 ? attribTree(tree.arg, env, VAR, Type.noType)
1905 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
1906
1907 // Find operator.
1908 Symbol operator = tree.operator =
1909 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
1910
1911 Type owntype = types.createErrorType(tree.type);
1912 if (operator.kind == MTH) {
1913 owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1914 ? tree.arg.type
1915 : operator.type.getReturnType();
1916 int opc = ((OperatorSymbol)operator).opcode;
1917
1918 // If the argument is constant, fold it.
1919 if (argtype.constValue() != null) {
1920 Type ctype = cfolder.fold1(opc, argtype);
1921 if (ctype != null) {
1922 owntype = cfolder.coerce(ctype, owntype);
1923
1924 // Remove constant types from arguments to
1925 // conserve space. The parser will fold concatenations
1926 // of string literals; the code here also
1927 // gets rid of intermediate results when some of the
1928 // operands are constant identifiers.
1929 if (tree.arg.type.tsym == syms.stringType.tsym) {
1930 tree.arg.type = syms.stringType;
1931 }
1932 }
1933 }
1934 }
1935 result = check(tree, owntype, VAL, pkind, pt);
1936 }
1937
1938 public void visitBinary(JCBinary tree) {
1939 // Attribute arguments.
1940 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
1941 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
1942
1943 // Find operator.
1944 Symbol operator = tree.operator =
1945 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
1946
1947 Type owntype = types.createErrorType(tree.type);
1948 if (operator.kind == MTH) {
1949 owntype = operator.type.getReturnType();
1950 int opc = chk.checkOperator(tree.lhs.pos(),
1951 (OperatorSymbol)operator,
1952 tree.getTag(),
1953 left,
1954 right);
1955
1956 // If both arguments are constants, fold them.
1957 if (left.constValue() != null && right.constValue() != null) {
1958 Type ctype = cfolder.fold2(opc, left, right);
1959 if (ctype != null) {
1960 owntype = cfolder.coerce(ctype, owntype);
1961
1962 // Remove constant types from arguments to
1963 // conserve space. The parser will fold concatenations
1964 // of string literals; the code here also
1965 // gets rid of intermediate results when some of the
1966 // operands are constant identifiers.
1967 if (tree.lhs.type.tsym == syms.stringType.tsym) {
1968 tree.lhs.type = syms.stringType;
1969 }
1970 if (tree.rhs.type.tsym == syms.stringType.tsym) {
1971 tree.rhs.type = syms.stringType;
1972 }
1973 }
1974 }
1975
1976 // Check that argument types of a reference ==, != are
1977 // castable to each other, (JLS???).
1978 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
1979 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
1980 log.error(tree.pos(), "incomparable.types", left, right);
1981 }
1982 }
1983
1984 chk.checkDivZero(tree.rhs.pos(), operator, right);
1985 }
1986 result = check(tree, owntype, VAL, pkind, pt);
1987 }
1988
1989 public void visitTypeCast(JCTypeCast tree) {
1990 Type clazztype = attribType(tree.clazz, env);
1991 chk.validate(tree.clazz, env);
1992 Type exprtype = attribExpr(tree.expr, env, Infer.anyPoly);
1993 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1994 if (exprtype.constValue() != null)
1995 owntype = cfolder.coerce(exprtype, owntype);
1996 result = check(tree, capture(owntype), VAL, pkind, pt);
1997 }
1998
1999 public void visitTypeTest(JCInstanceOf tree) {
2000 Type exprtype = chk.checkNullOrRefType(
2001 tree.expr.pos(), attribExpr(tree.expr, env));
2002 Type clazztype = chk.checkReifiableReferenceType(
2003 tree.clazz.pos(), attribType(tree.clazz, env));
2004 chk.validate(tree.clazz, env);
2005 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2006 result = check(tree, syms.booleanType, VAL, pkind, pt);
2007 }
2008
2009 public void visitIndexed(JCArrayAccess tree) {
2010 Type owntype = types.createErrorType(tree.type);
2011 Type atype = attribExpr(tree.indexed, env);
2012 attribExpr(tree.index, env, syms.intType);
2013 if (types.isArray(atype))
2014 owntype = types.elemtype(atype);
2015 else if (atype.tag != ERROR)
2016 log.error(tree.pos(), "array.req.but.found", atype);
2017 if ((pkind & VAR) == 0) owntype = capture(owntype);
2018 result = check(tree, owntype, VAR, pkind, pt);
2019 }
2020
2021 public void visitIdent(JCIdent tree) {
2022 Symbol sym;
2023 boolean varArgs = false;
2024
2025 // Find symbol
2026 if (pt.tag == METHOD || pt.tag == FORALL) {
2027 // If we are looking for a method, the prototype `pt' will be a
2028 // method type with the type of the call's arguments as parameters.
2029 env.info.varArgs = false;
2030 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
2031 varArgs = env.info.varArgs;
2032 } else if (tree.sym != null && tree.sym.kind != VAR) {
2033 sym = tree.sym;
2034 } else {
2035 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
2036 }
2037 tree.sym = sym;
2038
2039 // (1) Also find the environment current for the class where
2040 // sym is defined (`symEnv').
2041 // Only for pre-tiger versions (1.4 and earlier):
2042 // (2) Also determine whether we access symbol out of an anonymous
2043 // class in a this or super call. This is illegal for instance
2044 // members since such classes don't carry a this$n link.
2045 // (`noOuterThisPath').
2046 Env<AttrContext> symEnv = env;
2047 boolean noOuterThisPath = false;
2048 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
2049 (sym.kind & (VAR | MTH | TYP)) != 0 &&
2050 sym.owner.kind == TYP &&
2051 tree.name != names._this && tree.name != names._super) {
2052
2053 // Find environment in which identifier is defined.
2054 while (symEnv.outer != null &&
2055 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
2056 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
2057 noOuterThisPath = !allowAnonOuterThis;
2058 symEnv = symEnv.outer;
2059 }
2060 }
2061
2062 // If symbol is a variable, ...
2063 if (sym.kind == VAR) {
2064 VarSymbol v = (VarSymbol)sym;
2065
2066 // ..., evaluate its initializer, if it has one, and check for
2067 // illegal forward reference.
2068 checkInit(tree, env, v, false);
2069
2070 // If symbol is a local variable accessed from an embedded
2071 // inner class check that it is final.
2072 if (v.owner.kind == MTH &&
2073 v.owner != env.info.scope.owner &&
2074 (v.flags_field & FINAL) == 0) {
2075 log.error(tree.pos(),
2076 "local.var.accessed.from.icls.needs.final",
2077 v);
2078 }
2079
2080 // If we are expecting a variable (as opposed to a value), check
2081 // that the variable is assignable in the current environment.
2082 if (pkind == VAR)
2083 checkAssignable(tree.pos(), v, null, env);
2084 }
2085
2086 // In a constructor body,
2087 // if symbol is a field or instance method, check that it is
2088 // not accessed before the supertype constructor is called.
2089 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
2090 (sym.kind & (VAR | MTH)) != 0 &&
2091 sym.owner.kind == TYP &&
2092 (sym.flags() & STATIC) == 0) {
2093 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
2094 }
2095 Env<AttrContext> env1 = env;
2096 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
2097 // If the found symbol is inaccessible, then it is
2098 // accessed through an enclosing instance. Locate this
2099 // enclosing instance:
2100 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
2101 env1 = env1.outer;
2102 }
2103 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
2104 }
2105
2106 public void visitSelect(JCFieldAccess tree) {
2107 // Determine the expected kind of the qualifier expression.
2108 int skind = 0;
2109 if (tree.name == names._this || tree.name == names._super ||
2110 tree.name == names._class)
2111 {
2112 skind = TYP;
2113 } else {
2114 if ((pkind & PCK) != 0) skind = skind | PCK;
2115 if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
2116 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
2117 }
2118
2119 // Attribute the qualifier expression, and determine its symbol (if any).
2120 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
2121 if ((pkind & (PCK | TYP)) == 0)
2122 site = capture(site); // Capture field access
2123
2124 // don't allow T.class T[].class, etc
2125 if (skind == TYP) {
2126 Type elt = site;
2127 while (elt.tag == ARRAY)
2128 elt = ((ArrayType)elt).elemtype;
2129 if (elt.tag == TYPEVAR) {
2130 log.error(tree.pos(), "type.var.cant.be.deref");
2131 result = types.createErrorType(tree.type);
2132 return;
2133 }
2134 }
2135
2136 // If qualifier symbol is a type or `super', assert `selectSuper'
2137 // for the selection. This is relevant for determining whether
2138 // protected symbols are accessible.
2139 Symbol sitesym = TreeInfo.symbol(tree.selected);
2140 boolean selectSuperPrev = env.info.selectSuper;
2141 env.info.selectSuper =
2142 sitesym != null &&
2143 sitesym.name == names._super;
2144
2145 // If selected expression is polymorphic, strip
2146 // type parameters and remember in env.info.tvars, so that
2147 // they can be added later (in Attr.checkId and Infer.instantiateMethod).
2148 if (tree.selected.type.tag == FORALL) {
2149 ForAll pstype = (ForAll)tree.selected.type;
2150 env.info.tvars = pstype.tvars;
2151 site = tree.selected.type = pstype.qtype;
2152 }
2153
2154 // Determine the symbol represented by the selection.
2155 env.info.varArgs = false;
2156 Symbol sym = selectSym(tree, site, env, pt, pkind);
2157 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
2158 site = capture(site);
2159 sym = selectSym(tree, site, env, pt, pkind);
2160 }
2161 boolean varArgs = env.info.varArgs;
2162 tree.sym = sym;
2163
2164 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
2165 while (site.tag == TYPEVAR) site = site.getUpperBound();
2166 site = capture(site);
2167 }
2168
2169 // If that symbol is a variable, ...
2170 if (sym.kind == VAR) {
2171 VarSymbol v = (VarSymbol)sym;
2172
2173 // ..., evaluate its initializer, if it has one, and check for
2174 // illegal forward reference.
2175 checkInit(tree, env, v, true);
2176
2177 // If we are expecting a variable (as opposed to a value), check
2178 // that the variable is assignable in the current environment.
2179 if (pkind == VAR)
2180 checkAssignable(tree.pos(), v, tree.selected, env);
2181 }
2182
2183 if (sitesym != null &&
2184 sitesym.kind == VAR &&
2185 ((VarSymbol)sitesym).isResourceVariable() &&
2186 sym.kind == MTH &&
2187 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
2188 env.info.lint.isEnabled(Lint.LintCategory.ARM)) {
2189 log.warning(tree, "twr.explicit.close.call");
2190 }
2191
2192 // Disallow selecting a type from an expression
2193 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
2194 tree.type = check(tree.selected, pt,
2195 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
2196 }
2197
2198 if (isType(sitesym)) {
2199 if (sym.name == names._this) {
2200 // If `C' is the currently compiled class, check that
2201 // C.this' does not appear in a call to a super(...)
2202 if (env.info.isSelfCall &&
2203 site.tsym == env.enclClass.sym) {
2204 chk.earlyRefError(tree.pos(), sym);
2205 }
2206 } else {
2207 // Check if type-qualified fields or methods are static (JLS)
2208 if ((sym.flags() & STATIC) == 0 &&
2209 sym.name != names._super &&
2210 (sym.kind == VAR || sym.kind == MTH)) {
2211 rs.access(rs.new StaticError(sym),
2212 tree.pos(), site, sym.name, true);
2213 }
2214 }
2215 } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
2216 // If the qualified item is not a type and the selected item is static, report
2217 // a warning. Make allowance for the class of an array type e.g. Object[].class)
2218 chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
2219 }
2220
2221 // If we are selecting an instance member via a `super', ...
2222 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
2223
2224 // Check that super-qualified symbols are not abstract (JLS)
2225 rs.checkNonAbstract(tree.pos(), sym);
2226
2227 if (site.isRaw()) {
2228 // Determine argument types for site.
2229 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
2230 if (site1 != null) site = site1;
2231 }
2232 }
2233
2234 env.info.selectSuper = selectSuperPrev;
2235 result = checkId(tree, site, sym, env, pkind, pt, varArgs);
2236 env.info.tvars = List.nil();
2237 }
2238 //where
2239 /** Determine symbol referenced by a Select expression,
2240 *
2241 * @param tree The select tree.
2242 * @param site The type of the selected expression,
2243 * @param env The current environment.
2244 * @param pt The current prototype.
2245 * @param pkind The expected kind(s) of the Select expression.
2246 */
2247 private Symbol selectSym(JCFieldAccess tree,
2248 Type site,
2249 Env<AttrContext> env,
2250 Type pt,
2251 int pkind) {
2252 DiagnosticPosition pos = tree.pos();
2253 Name name = tree.name;
2254
2255 switch (site.tag) {
2256 case PACKAGE:
2257 return rs.access(
2258 rs.findIdentInPackage(env, site.tsym, name, pkind),
2259 pos, site, name, true);
2260 case ARRAY:
2261 case CLASS:
2262 if (pt.tag == METHOD || pt.tag == FORALL) {
2263 return rs.resolveQualifiedMethod(
2264 pos, env, site, name, pt.getParameterTypes(), pt.getTypeArguments());
2265 } else if (name == names._this || name == names._super) {
2266 return rs.resolveSelf(pos, env, site.tsym, name);
2267 } else if (name == names._class) {
2268 // In this case, we have already made sure in
2269 // visitSelect that qualifier expression is a type.
2270 Type t = syms.classType;
2271 List<Type> typeargs = allowGenerics
2272 ? List.of(types.erasure(site))
2273 : List.<Type>nil();
2274 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
2275 return new VarSymbol(
2276 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2277 } else {
2278 // We are seeing a plain identifier as selector.
2279 Symbol sym = rs.findIdentInType(env, site, name, pkind);
2280 if ((pkind & ERRONEOUS) == 0)
2281 sym = rs.access(sym, pos, site, name, true);
2282 return sym;
2283 }
2284 case WILDCARD:
2285 throw new AssertionError(tree);
2286 case TYPEVAR:
2287 // Normally, site.getUpperBound() shouldn't be null.
2288 // It should only happen during memberEnter/attribBase
2289 // when determining the super type which *must* be
2290 // done before attributing the type variables. In
2291 // other words, we are seeing this illegal program:
2292 // class B<T> extends A<T.foo> {}
2293 Symbol sym = (site.getUpperBound() != null)
2294 ? selectSym(tree, capture(site.getUpperBound()), env, pt, pkind)
2295 : null;
2296 if (sym == null) {
2297 log.error(pos, "type.var.cant.be.deref");
2298 return syms.errSymbol;
2299 } else {
2300 Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
2301 rs.new AccessError(env, site, sym) :
2302 sym;
2303 rs.access(sym2, pos, site, name, true);
2304 return sym;
2305 }
2306 case ERROR:
2307 // preserve identifier names through errors
2308 return types.createErrorType(name, site.tsym, site).tsym;
2309 default:
2310 // The qualifier expression is of a primitive type -- only
2311 // .class is allowed for these.
2312 if (name == names._class) {
2313 // In this case, we have already made sure in Select that
2314 // qualifier expression is a type.
2315 Type t = syms.classType;
2316 Type arg = types.boxedClass(site).type;
2317 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2318 return new VarSymbol(
2319 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2320 } else {
2321 log.error(pos, "cant.deref", site);
2322 return syms.errSymbol;
2323 }
2324 }
2325 }
2326
2327 /** Determine type of identifier or select expression and check that
2328 * (1) the referenced symbol is not deprecated
2329 * (2) the symbol's type is safe (@see checkSafe)
2330 * (3) if symbol is a variable, check that its type and kind are
2331 * compatible with the prototype and protokind.
2332 * (4) if symbol is an instance field of a raw type,
2333 * which is being assigned to, issue an unchecked warning if its
2334 * type changes under erasure.
2335 * (5) if symbol is an instance method of a raw type, issue an
2336 * unchecked warning if its argument types change under erasure.
2337 * If checks succeed:
2338 * If symbol is a constant, return its constant type
2339 * else if symbol is a method, return its result type
2340 * otherwise return its type.
2341 * Otherwise return errType.
2342 *
2343 * @param tree The syntax tree representing the identifier
2344 * @param site If this is a select, the type of the selected
2345 * expression, otherwise the type of the current class.
2346 * @param sym The symbol representing the identifier.
2347 * @param env The current environment.
2348 * @param pkind The set of expected kinds.
2349 * @param pt The expected type.
2350 */
2351 Type checkId(JCTree tree,
2352 Type site,
2353 Symbol sym,
2354 Env<AttrContext> env,
2355 int pkind,
2356 Type pt,
2357 boolean useVarargs) {
2358 if (pt.isErroneous()) return types.createErrorType(site);
2359 Type owntype; // The computed type of this identifier occurrence.
2360 switch (sym.kind) {
2361 case TYP:
2362 // For types, the computed type equals the symbol's type,
2363 // except for two situations:
2364 owntype = sym.type;
2365 if (owntype.tag == CLASS) {
2366 Type ownOuter = owntype.getEnclosingType();
2367
2368 // (a) If the symbol's type is parameterized, erase it
2369 // because no type parameters were given.
2370 // We recover generic outer type later in visitTypeApply.
2371 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2372 owntype = types.erasure(owntype);
2373 }
2374
2375 // (b) If the symbol's type is an inner class, then
2376 // we have to interpret its outer type as a superclass
2377 // of the site type. Example:
2378 //
2379 // class Tree<A> { class Visitor { ... } }
2380 // class PointTree extends Tree<Point> { ... }
2381 // ...PointTree.Visitor...
2382 //
2383 // Then the type of the last expression above is
2384 // Tree<Point>.Visitor.
2385 else if (ownOuter.tag == CLASS && site != ownOuter) {
2386 Type normOuter = site;
2387 if (normOuter.tag == CLASS)
2388 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2389 if (normOuter == null) // perhaps from an import
2390 normOuter = types.erasure(ownOuter);
2391 if (normOuter != ownOuter)
2392 owntype = new ClassType(
2393 normOuter, List.<Type>nil(), owntype.tsym);
2394 }
2395 }
2396 break;
2397 case VAR:
2398 VarSymbol v = (VarSymbol)sym;
2399 // Test (4): if symbol is an instance field of a raw type,
2400 // which is being assigned to, issue an unchecked warning if
2401 // its type changes under erasure.
2402 if (allowGenerics &&
2403 pkind == VAR &&
2404 v.owner.kind == TYP &&
2405 (v.flags() & STATIC) == 0 &&
2406 (site.tag == CLASS || site.tag == TYPEVAR)) {
2407 Type s = types.asOuterSuper(site, v.owner);
2408 if (s != null &&
2409 s.isRaw() &&
2410 !types.isSameType(v.type, v.erasure(types))) {
2411 chk.warnUnchecked(tree.pos(),
2412 "unchecked.assign.to.var",
2413 v, s);
2414 }
2415 }
2416 // The computed type of a variable is the type of the
2417 // variable symbol, taken as a member of the site type.
2418 owntype = (sym.owner.kind == TYP &&
2419 sym.name != names._this && sym.name != names._super)
2420 ? types.memberType(site, sym)
2421 : sym.type;
2422
2423 if (env.info.tvars.nonEmpty()) {
2424 Type owntype1 = new ForAll(env.info.tvars, owntype);
2425 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2426 if (!owntype.contains(l.head)) {
2427 log.error(tree.pos(), "undetermined.type", owntype1);
2428 owntype1 = types.createErrorType(owntype1);
2429 }
2430 owntype = owntype1;
2431 }
2432
2433 // If the variable is a constant, record constant value in
2434 // computed type.
2435 if (v.getConstValue() != null && isStaticReference(tree))
2436 owntype = owntype.constType(v.getConstValue());
2437
2438 if (pkind == VAL) {
2439 owntype = capture(owntype); // capture "names as expressions"
2440 }
2441 break;
2442 case MTH: {
2443 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2444 owntype = checkMethod(site, sym, env, app.args,
2445 pt.getParameterTypes(), pt.getTypeArguments(),
2446 env.info.varArgs);
2447 break;
2448 }
2449 case PCK: case ERR:
2450 owntype = sym.type;
2451 break;
2452 default:
2453 throw new AssertionError("unexpected kind: " + sym.kind +
2454 " in tree " + tree);
2455 }
2456
2457 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2458 // (for constructors, the error was given when the constructor was
2459 // resolved)
2460 if (sym.name != names.init &&
2461 (sym.flags() & DEPRECATED) != 0 &&
2462 (env.info.scope.owner.flags() & DEPRECATED) == 0 &&
2463 sym.outermostClass() != env.info.scope.owner.outermostClass())
2464 chk.warnDeprecated(tree.pos(), sym);
2465
2466 if ((sym.flags() & PROPRIETARY) != 0) {
2467 if (enableSunApiLintControl)
2468 chk.warnSunApi(tree.pos(), "sun.proprietary", sym);
2469 else
2470 log.strictWarning(tree.pos(), "sun.proprietary", sym);
2471 }
2472
2473 // Test (3): if symbol is a variable, check that its type and
2474 // kind are compatible with the prototype and protokind.
2475 return check(tree, owntype, sym.kind, pkind, pt);
2476 }
2477
2478 /** Check that variable is initialized and evaluate the variable's
2479 * initializer, if not yet done. Also check that variable is not
2480 * referenced before it is defined.
2481 * @param tree The tree making up the variable reference.
2482 * @param env The current environment.
2483 * @param v The variable's symbol.
2484 */
2485 private void checkInit(JCTree tree,
2486 Env<AttrContext> env,
2487 VarSymbol v,
2488 boolean onlyWarning) {
2489 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2490 // tree.pos + " " + v.pos + " " +
2491 // Resolve.isStatic(env));//DEBUG
2492
2493 // A forward reference is diagnosed if the declaration position
2494 // of the variable is greater than the current tree position
2495 // and the tree and variable definition occur in the same class
2496 // definition. Note that writes don't count as references.
2497 // This check applies only to class and instance
2498 // variables. Local variables follow different scope rules,
2499 // and are subject to definite assignment checking.
2500 if ((env.info.enclVar == v || v.pos > tree.pos) &&
2501 v.owner.kind == TYP &&
2502 canOwnInitializer(env.info.scope.owner) &&
2503 v.owner == env.info.scope.owner.enclClass() &&
2504 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2505 (env.tree.getTag() != JCTree.ASSIGN ||
2506 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2507 String suffix = (env.info.enclVar == v) ?
2508 "self.ref" : "forward.ref";
2509 if (!onlyWarning || isStaticEnumField(v)) {
2510 log.error(tree.pos(), "illegal." + suffix);
2511 } else if (useBeforeDeclarationWarning) {
2512 log.warning(tree.pos(), suffix, v);
2513 }
2514 }
2515
2516 v.getConstValue(); // ensure initializer is evaluated
2517
2518 checkEnumInitializer(tree, env, v);
2519 }
2520
2521 /**
2522 * Check for illegal references to static members of enum. In
2523 * an enum type, constructors and initializers may not
2524 * reference its static members unless they are constant.
2525 *
2526 * @param tree The tree making up the variable reference.
2527 * @param env The current environment.
2528 * @param v The variable's symbol.
2529 * @see JLS 3rd Ed. (8.9 Enums)
2530 */
2531 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2532 // JLS 3rd Ed.:
2533 //
2534 // "It is a compile-time error to reference a static field
2535 // of an enum type that is not a compile-time constant
2536 // (15.28) from constructors, instance initializer blocks,
2537 // or instance variable initializer expressions of that
2538 // type. It is a compile-time error for the constructors,
2539 // instance initializer blocks, or instance variable
2540 // initializer expressions of an enum constant e to refer
2541 // to itself or to an enum constant of the same type that
2542 // is declared to the right of e."
2543 if (isStaticEnumField(v)) {
2544 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2545
2546 if (enclClass == null || enclClass.owner == null)
2547 return;
2548
2549 // See if the enclosing class is the enum (or a
2550 // subclass thereof) declaring v. If not, this
2551 // reference is OK.
2552 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2553 return;
2554
2555 // If the reference isn't from an initializer, then
2556 // the reference is OK.
2557 if (!Resolve.isInitializer(env))
2558 return;
2559
2560 log.error(tree.pos(), "illegal.enum.static.ref");
2561 }
2562 }
2563
2564 /** Is the given symbol a static, non-constant field of an Enum?
2565 * Note: enum literals should not be regarded as such
2566 */
2567 private boolean isStaticEnumField(VarSymbol v) {
2568 return Flags.isEnum(v.owner) &&
2569 Flags.isStatic(v) &&
2570 !Flags.isConstant(v) &&
2571 v.name != names._class;
2572 }
2573
2574 /** Can the given symbol be the owner of code which forms part
2575 * if class initialization? This is the case if the symbol is
2576 * a type or field, or if the symbol is the synthetic method.
2577 * owning a block.
2578 */
2579 private boolean canOwnInitializer(Symbol sym) {
2580 return
2581 (sym.kind & (VAR | TYP)) != 0 ||
2582 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2583 }
2584
2585 Warner noteWarner = new Warner();
2586
2587 /**
2588 * Check that method arguments conform to its instantation.
2589 **/
2590 public Type checkMethod(Type site,
2591 Symbol sym,
2592 Env<AttrContext> env,
2593 final List<JCExpression> argtrees,
2594 List<Type> argtypes,
2595 List<Type> typeargtypes,
2596 boolean useVarargs) {
2597 // Test (5): if symbol is an instance method of a raw type, issue
2598 // an unchecked warning if its argument types change under erasure.
2599 if (allowGenerics &&
2600 (sym.flags() & STATIC) == 0 &&
2601 (site.tag == CLASS || site.tag == TYPEVAR)) {
2602 Type s = types.asOuterSuper(site, sym.owner);
2603 if (s != null && s.isRaw() &&
2604 !types.isSameTypes(sym.type.getParameterTypes(),
2605 sym.erasure(types).getParameterTypes())) {
2606 chk.warnUnchecked(env.tree.pos(),
2607 "unchecked.call.mbr.of.raw.type",
2608 sym, s);
2609 }
2610 }
2611
2612 // Compute the identifier's instantiated type.
2613 // For methods, we need to compute the instance type by
2614 // Resolve.instantiate from the symbol's type as well as
2615 // any type arguments and value arguments.
2616 noteWarner.warned = false;
2617 Type owntype = rs.instantiate(env,
2618 site,
2619 sym,
2620 argtypes,
2621 typeargtypes,
2622 true,
2623 useVarargs,
2624 noteWarner);
2625 boolean warned = noteWarner.warned;
2626
2627 // If this fails, something went wrong; we should not have
2628 // found the identifier in the first place.
2629 if (owntype == null) {
2630 if (!pt.isErroneous())
2631 log.error(env.tree.pos(),
2632 "internal.error.cant.instantiate",
2633 sym, site,
2634 Type.toString(pt.getParameterTypes()));
2635 owntype = types.createErrorType(site);
2636 } else {
2637 // System.out.println("call : " + env.tree);
2638 // System.out.println("method : " + owntype);
2639 // System.out.println("actuals: " + argtypes);
2640 List<Type> formals = owntype.getParameterTypes();
2641 Type last = useVarargs ? formals.last() : null;
2642 if (sym.name==names.init &&
2643 sym.owner == syms.enumSym)
2644 formals = formals.tail.tail;
2645 List<JCExpression> args = argtrees;
2646 while (formals.head != last) {
2647 JCTree arg = args.head;
2648 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2649 assertConvertible(arg, arg.type, formals.head, warn);
2650 warned |= warn.warned;
2651 args = args.tail;
2652 formals = formals.tail;
2653 }
2654 if (useVarargs) {
2655 Type varArg = types.elemtype(last);
2656 while (args.tail != null) {
2657 JCTree arg = args.head;
2658 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2659 assertConvertible(arg, arg.type, varArg, warn);
2660 warned |= warn.warned;
2661 args = args.tail;
2662 }
2663 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2664 // non-varargs call to varargs method
2665 Type varParam = owntype.getParameterTypes().last();
2666 Type lastArg = argtypes.last();
2667 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2668 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2669 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2670 types.elemtype(varParam),
2671 varParam);
2672 }
2673
2674 if (warned && sym.type.tag == FORALL) {
2675 chk.warnUnchecked(env.tree.pos(),
2676 "unchecked.meth.invocation.applied",
2677 kindName(sym),
2678 sym.name,
2679 rs.methodArguments(sym.type.getParameterTypes()),
2680 rs.methodArguments(argtypes),
2681 kindName(sym.location()),
2682 sym.location());
2683 owntype = new MethodType(owntype.getParameterTypes(),
2684 types.erasure(owntype.getReturnType()),
2685 owntype.getThrownTypes(),
2686 syms.methodClass);
2687 }
2688 if (useVarargs) {
2689 JCTree tree = env.tree;
2690 Type argtype = owntype.getParameterTypes().last();
2691 if (owntype.getReturnType().tag != FORALL || warned) {
2692 chk.checkVararg(env.tree.pos(), owntype.getParameterTypes(), sym, env);
2693 }
2694 Type elemtype = types.elemtype(argtype);
2695 switch (tree.getTag()) {
2696 case JCTree.APPLY:
2697 ((JCMethodInvocation) tree).varargsElement = elemtype;
2698 break;
2699 case JCTree.NEWCLASS:
2700 ((JCNewClass) tree).varargsElement = elemtype;
2701 break;
2702 default:
2703 throw new AssertionError(""+tree);
2704 }
2705 }
2706 }
2707 return owntype;
2708 }
2709
2710 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2711 if (types.isConvertible(actual, formal, warn))
2712 return;
2713
2714 if (formal.isCompound()
2715 && types.isSubtype(actual, types.supertype(formal))
2716 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2717 return;
2718
2719 if (false) {
2720 // TODO: make assertConvertible work
2721 chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal);
2722 throw new AssertionError("Tree: " + tree
2723 + " actual:" + actual
2724 + " formal: " + formal);
2725 }
2726 }
2727
2728 public void visitLiteral(JCLiteral tree) {
2729 result = check(
2730 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2731 }
2732 //where
2733 /** Return the type of a literal with given type tag.
2734 */
2735 Type litType(int tag) {
2736 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2737 }
2738
2739 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2740 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2741 }
2742
2743 public void visitTypeArray(JCArrayTypeTree tree) {
2744 Type etype = attribType(tree.elemtype, env);
2745 Type type = new ArrayType(etype, syms.arrayClass);
2746 result = check(tree, type, TYP, pkind, pt);
2747 }
2748
2749 /** Visitor method for parameterized types.
2750 * Bound checking is left until later, since types are attributed
2751 * before supertype structure is completely known
2752 */
2753 public void visitTypeApply(JCTypeApply tree) {
2754 Type owntype = types.createErrorType(tree.type);
2755
2756 // Attribute functor part of application and make sure it's a class.
2757 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2758
2759 // Attribute type parameters
2760 List<Type> actuals = attribTypes(tree.arguments, env);
2761
2762 if (clazztype.tag == CLASS) {
2763 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2764
2765 if (actuals.length() == formals.length() || actuals.length() == 0) {
2766 List<Type> a = actuals;
2767 List<Type> f = formals;
2768 while (a.nonEmpty()) {
2769 a.head = a.head.withTypeVar(f.head);
2770 a = a.tail;
2771 f = f.tail;
2772 }
2773 // Compute the proper generic outer
2774 Type clazzOuter = clazztype.getEnclosingType();
2775 if (clazzOuter.tag == CLASS) {
2776 Type site;
2777 JCExpression clazz = TreeInfo.typeIn(tree.clazz);
2778 if (clazz.getTag() == JCTree.IDENT) {
2779 site = env.enclClass.sym.type;
2780 } else if (clazz.getTag() == JCTree.SELECT) {
2781 site = ((JCFieldAccess) clazz).selected.type;
2782 } else throw new AssertionError(""+tree);
2783 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2784 if (site.tag == CLASS)
2785 site = types.asOuterSuper(site, clazzOuter.tsym);
2786 if (site == null)
2787 site = types.erasure(clazzOuter);
2788 clazzOuter = site;
2789 }
2790 }
2791 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2792 } else {
2793 if (formals.length() != 0) {
2794 log.error(tree.pos(), "wrong.number.type.args",
2795 Integer.toString(formals.length()));
2796 } else {
2797 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2798 }
2799 owntype = types.createErrorType(tree.type);
2800 }
2801 }
2802 result = check(tree, owntype, TYP, pkind, pt);
2803 }
2804
2805 public void visitTypeDisjoint(JCTypeDisjoint tree) {
2806 List<Type> componentTypes = attribTypes(tree.components, env);
2807 tree.type = result = check(tree, types.lub(componentTypes), TYP, pkind, pt);
2808 }
2809
2810 public void visitTypeParameter(JCTypeParameter tree) {
2811 TypeVar a = (TypeVar)tree.type;
2812 Set<Type> boundSet = new HashSet<Type>();
2813 if (a.bound.isErroneous())
2814 return;
2815 List<Type> bs = types.getBounds(a);
2816 if (tree.bounds.nonEmpty()) {
2817 // accept class or interface or typevar as first bound.
2818 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2819 boundSet.add(types.erasure(b));
2820 if (b.isErroneous()) {
2821 a.bound = b;
2822 }
2823 else if (b.tag == TYPEVAR) {
2824 // if first bound was a typevar, do not accept further bounds.
2825 if (tree.bounds.tail.nonEmpty()) {
2826 log.error(tree.bounds.tail.head.pos(),
2827 "type.var.may.not.be.followed.by.other.bounds");
2828 log.unrecoverableError = true;
2829 tree.bounds = List.of(tree.bounds.head);
2830 a.bound = bs.head;
2831 }
2832 } else {
2833 // if first bound was a class or interface, accept only interfaces
2834 // as further bounds.
2835 for (JCExpression bound : tree.bounds.tail) {
2836 bs = bs.tail;
2837 Type i = checkBase(bs.head, bound, env, false, true, false);
2838 if (i.isErroneous())
2839 a.bound = i;
2840 else if (i.tag == CLASS)
2841 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
2842 }
2843 }
2844 }
2845 bs = types.getBounds(a);
2846
2847 // in case of multiple bounds ...
2848 if (bs.length() > 1) {
2849 // ... the variable's bound is a class type flagged COMPOUND
2850 // (see comment for TypeVar.bound).
2851 // In this case, generate a class tree that represents the
2852 // bound class, ...
2853 JCTree extending;
2854 List<JCExpression> implementing;
2855 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
2856 extending = tree.bounds.head;
2857 implementing = tree.bounds.tail;
2858 } else {
2859 extending = null;
2860 implementing = tree.bounds;
2861 }
2862 JCClassDecl cd = make.at(tree.pos).ClassDef(
2863 make.Modifiers(PUBLIC | ABSTRACT),
2864 tree.name, List.<JCTypeParameter>nil(),
2865 extending, implementing, List.<JCTree>nil());
2866
2867 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
2868 assert (c.flags() & COMPOUND) != 0;
2869 cd.sym = c;
2870 c.sourcefile = env.toplevel.sourcefile;
2871
2872 // ... and attribute the bound class
2873 c.flags_field |= UNATTRIBUTED;
2874 Env<AttrContext> cenv = enter.classEnv(cd, env);
2875 enter.typeEnvs.put(c, cenv);
2876 }
2877 }
2878
2879
2880 public void visitWildcard(JCWildcard tree) {
2881 //- System.err.println("visitWildcard("+tree+");");//DEBUG
2882 Type type = (tree.kind.kind == BoundKind.UNBOUND)
2883 ? syms.objectType
2884 : attribType(tree.inner, env);
2885 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
2886 tree.kind.kind,
2887 syms.boundClass),
2888 TYP, pkind, pt);
2889 }
2890
2891 public void visitAnnotation(JCAnnotation tree) {
2892 log.error(tree.pos(), "annotation.not.valid.for.type", pt);
2893 result = tree.type = syms.errType;
2894 }
2895
2896 public void visitAnnotatedType(JCAnnotatedType tree) {
2897 result = tree.type = attribType(tree.getUnderlyingType(), env);
2898 }
2899
2900 public void visitErroneous(JCErroneous tree) {
2901 if (tree.errs != null)
2902 for (JCTree err : tree.errs)
2903 attribTree(err, env, ERR, pt);
2904 result = tree.type = syms.errType;
2905 }
2906
2907 /** Default visitor method for all other trees.
2908 */
2909 public void visitTree(JCTree tree) {
2910 throw new AssertionError();
2911 }
2912
2913 /** Main method: attribute class definition associated with given class symbol.
2914 * reporting completion failures at the given position.
2915 * @param pos The source position at which completion errors are to be
2916 * reported.
2917 * @param c The class symbol whose definition will be attributed.
2918 */
2919 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
2920 try {
2921 annotate.flush();
2922 attribClass(c);
2923 } catch (CompletionFailure ex) {
2924 chk.completionError(pos, ex);
2925 }
2926 }
2927
2928 /** Attribute class definition associated with given class symbol.
2929 * @param c The class symbol whose definition will be attributed.
2930 */
2931 void attribClass(ClassSymbol c) throws CompletionFailure {
2932 if (c.type.tag == ERROR) return;
2933
2934 // Check for cycles in the inheritance graph, which can arise from
2935 // ill-formed class files.
2936 chk.checkNonCyclic(null, c.type);
2937
2938 Type st = types.supertype(c.type);
2939 if ((c.flags_field & Flags.COMPOUND) == 0) {
2940 // First, attribute superclass.
2941 if (st.tag == CLASS)
2942 attribClass((ClassSymbol)st.tsym);
2943
2944 // Next attribute owner, if it is a class.
2945 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
2946 attribClass((ClassSymbol)c.owner);
2947 }
2948
2949 // The previous operations might have attributed the current class
2950 // if there was a cycle. So we test first whether the class is still
2951 // UNATTRIBUTED.
2952 if ((c.flags_field & UNATTRIBUTED) != 0) {
2953 c.flags_field &= ~UNATTRIBUTED;
2954
2955 // Get environment current at the point of class definition.
2956 Env<AttrContext> env = enter.typeEnvs.get(c);
2957
2958 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
2959 // because the annotations were not available at the time the env was created. Therefore,
2960 // we look up the environment chain for the first enclosing environment for which the
2961 // lint value is set. Typically, this is the parent env, but might be further if there
2962 // are any envs created as a result of TypeParameter nodes.
2963 Env<AttrContext> lintEnv = env;
2964 while (lintEnv.info.lint == null)
2965 lintEnv = lintEnv.next;
2966
2967 // Having found the enclosing lint value, we can initialize the lint value for this class
2968 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
2969
2970 Lint prevLint = chk.setLint(env.info.lint);
2971 JavaFileObject prev = log.useSource(c.sourcefile);
2972
2973 try {
2974 // java.lang.Enum may not be subclassed by a non-enum
2975 if (st.tsym == syms.enumSym &&
2976 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
2977 log.error(env.tree.pos(), "enum.no.subclassing");
2978
2979 // Enums may not be extended by source-level classes
2980 if (st.tsym != null &&
2981 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
2982 ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
2983 !target.compilerBootstrap(c)) {
2984 log.error(env.tree.pos(), "enum.types.not.extensible");
2985 }
2986 attribClassBody(env, c);
2987
2988 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
2989 } finally {
2990 log.useSource(prev);
2991 chk.setLint(prevLint);
2992 }
2993
2994 }
2995 }
2996
2997 public void visitImport(JCImport tree) {
2998 // nothing to do
2999 }
3000
3001 /** Finish the attribution of a class. */
3002 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
3003 JCClassDecl tree = (JCClassDecl)env.tree;
3004 assert c == tree.sym;
3005
3006 // Validate annotations
3007 chk.validateAnnotations(tree.mods.annotations, c);
3008
3009 // Validate type parameters, supertype and interfaces.
3010 attribBounds(tree.typarams);
3011 if (!c.isAnonymous()) {
3012 //already checked if anonymous
3013 chk.validate(tree.typarams, env);
3014 chk.validate(tree.extending, env);
3015 chk.validate(tree.implementing, env);
3016 }
3017
3018 // If this is a non-abstract class, check that it has no abstract
3019 // methods or unimplemented methods of an implemented interface.
3020 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
3021 if (!relax)
3022 chk.checkAllDefined(tree.pos(), c);
3023 }
3024
3025 if ((c.flags() & ANNOTATION) != 0) {
3026 if (tree.implementing.nonEmpty())
3027 log.error(tree.implementing.head.pos(),
3028 "cant.extend.intf.annotation");
3029 if (tree.typarams.nonEmpty())
3030 log.error(tree.typarams.head.pos(),
3031 "intf.annotation.cant.have.type.params");
3032 } else {
3033 // Check that all extended classes and interfaces
3034 // are compatible (i.e. no two define methods with same arguments
3035 // yet different return types). (JLS 8.4.6.3)
3036 chk.checkCompatibleSupertypes(tree.pos(), c.type);
3037 }
3038
3039 // Check that class does not import the same parameterized interface
3040 // with two different argument lists.
3041 chk.checkClassBounds(tree.pos(), c.type);
3042
3043 tree.type = c.type;
3044
3045 boolean assertsEnabled = false;
3046 assert assertsEnabled = true;
3047 if (assertsEnabled) {
3048 for (List<JCTypeParameter> l = tree.typarams;
3049 l.nonEmpty(); l = l.tail)
3050 assert env.info.scope.lookup(l.head.name).scope != null;
3051 }
3052
3053 // Check that a generic class doesn't extend Throwable
3054 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
3055 log.error(tree.extending.pos(), "generic.throwable");
3056
3057 // Check that all methods which implement some
3058 // method conform to the method they implement.
3059 chk.checkImplementations(tree);
3060
3061 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3062 // Attribute declaration
3063 attribStat(l.head, env);
3064 // Check that declarations in inner classes are not static (JLS 8.1.2)
3065 // Make an exception for static constants.
3066 if (c.owner.kind != PCK &&
3067 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
3068 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
3069 Symbol sym = null;
3070 if (l.head.getTag() == JCTree.VARDEF) sym = ((JCVariableDecl) l.head).sym;
3071 if (sym == null ||
3072 sym.kind != VAR ||
3073 ((VarSymbol) sym).getConstValue() == null)
3074 log.error(l.head.pos(), "icls.cant.have.static.decl");
3075 }
3076 }
3077
3078 // Check for cycles among non-initial constructors.
3079 chk.checkCyclicConstructors(tree);
3080
3081 // Check for cycles among annotation elements.
3082 chk.checkNonCyclicElements(tree);
3083
3084 // Check for proper use of serialVersionUID
3085 if (env.info.lint.isEnabled(Lint.LintCategory.SERIAL) &&
3086 isSerializable(c) &&
3087 (c.flags() & Flags.ENUM) == 0 &&
3088 (c.flags() & ABSTRACT) == 0) {
3089 checkSerialVersionUID(tree, c);
3090 }
3091
3092 // Check type annotations applicability rules
3093 validateTypeAnnotations(tree);
3094 }
3095 // where
3096 /** check if a class is a subtype of Serializable, if that is available. */
3097 private boolean isSerializable(ClassSymbol c) {
3098 try {
3099 syms.serializableType.complete();
3100 }
3101 catch (CompletionFailure e) {
3102 return false;
3103 }
3104 return types.isSubtype(c.type, syms.serializableType);
3105 }
3106
3107 /** Check that an appropriate serialVersionUID member is defined. */
3108 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
3109
3110 // check for presence of serialVersionUID
3111 Scope.Entry e = c.members().lookup(names.serialVersionUID);
3112 while (e.scope != null && e.sym.kind != VAR) e = e.next();
3113 if (e.scope == null) {
3114 log.warning(tree.pos(), "missing.SVUID", c);
3115 return;
3116 }
3117
3118 // check that it is static final
3119 VarSymbol svuid = (VarSymbol)e.sym;
3120 if ((svuid.flags() & (STATIC | FINAL)) !=
3121 (STATIC | FINAL))
3122 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
3123
3124 // check that it is long
3125 else if (svuid.type.tag != TypeTags.LONG)
3126 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
3127
3128 // check constant
3129 else if (svuid.getConstValue() == null)
3130 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
3131 }
3132
3133 private Type capture(Type type) {
3134 return types.capture(type);
3135 }
3136
3137 private void validateTypeAnnotations(JCTree tree) {
3138 tree.accept(typeAnnotationsValidator);
3139 }
3140 //where
3141 private final JCTree.Visitor typeAnnotationsValidator =
3142 new TreeScanner() {
3143 public void visitAnnotation(JCAnnotation tree) {
3144 if (tree instanceof JCTypeAnnotation) {
3145 chk.validateTypeAnnotation((JCTypeAnnotation)tree, false);
3146 }
3147 super.visitAnnotation(tree);
3148 }
3149 public void visitTypeParameter(JCTypeParameter tree) {
3150 chk.validateTypeAnnotations(tree.annotations, true);
3151 // don't call super. skip type annotations
3152 scan(tree.bounds);
3153 }
3154 public void visitMethodDef(JCMethodDecl tree) {
3155 // need to check static methods
3156 if ((tree.sym.flags() & Flags.STATIC) != 0) {
3157 for (JCTypeAnnotation a : tree.receiverAnnotations) {
3158 if (chk.isTypeAnnotation(a, false))
3159 log.error(a.pos(), "annotation.type.not.applicable");
3160 }
3161 }
3162 super.visitMethodDef(tree);
3163 }
3164 };
3165 }