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