Tue, 04 Mar 2008 15:45:20 +0000
6663588: Compiler goes into infinite loop for Cyclic Inheritance test case
Summary: interplay between cyclic inheritance and tvar bounds hangs javac
Reviewed-by: jjg
1 /*
2 * Copyright 1999-2006 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
26 package com.sun.tools.javac.comp;
28 import java.util.*;
29 import java.util.Set;
30 import javax.lang.model.element.ElementKind;
31 import javax.tools.JavaFileObject;
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;
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.*;
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;
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.*;
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 API supported by Sun Microsystems. If
63 * 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>();
71 final Name.Table names;
72 final Log log;
73 final Symtab syms;
74 final Resolve rs;
75 final Check chk;
76 final MemberEnter memberEnter;
77 final TreeMaker make;
78 final ConstFold cfolder;
79 final Enter enter;
80 final Target target;
81 final Types types;
82 final Annotate annotate;
84 public static Attr instance(Context context) {
85 Attr instance = context.get(attrKey);
86 if (instance == null)
87 instance = new Attr(context);
88 return instance;
89 }
91 protected Attr(Context context) {
92 context.put(attrKey, this);
94 names = Name.Table.instance(context);
95 log = Log.instance(context);
96 syms = Symtab.instance(context);
97 rs = Resolve.instance(context);
98 chk = Check.instance(context);
99 memberEnter = MemberEnter.instance(context);
100 make = TreeMaker.instance(context);
101 enter = Enter.instance(context);
102 cfolder = ConstFold.instance(context);
103 target = Target.instance(context);
104 types = Types.instance(context);
105 annotate = Annotate.instance(context);
107 Options options = Options.instance(context);
109 Source source = Source.instance(context);
110 allowGenerics = source.allowGenerics();
111 allowVarargs = source.allowVarargs();
112 allowEnums = source.allowEnums();
113 allowBoxing = source.allowBoxing();
114 allowCovariantReturns = source.allowCovariantReturns();
115 allowAnonOuterThis = source.allowAnonOuterThis();
116 relax = (options.get("-retrofit") != null ||
117 options.get("-relax") != null);
118 useBeforeDeclarationWarning = options.get("useBeforeDeclarationWarning") != null;
119 }
121 /** Switch: relax some constraints for retrofit mode.
122 */
123 boolean relax;
125 /** Switch: support generics?
126 */
127 boolean allowGenerics;
129 /** Switch: allow variable-arity methods.
130 */
131 boolean allowVarargs;
133 /** Switch: support enums?
134 */
135 boolean allowEnums;
137 /** Switch: support boxing and unboxing?
138 */
139 boolean allowBoxing;
141 /** Switch: support covariant result types?
142 */
143 boolean allowCovariantReturns;
145 /** Switch: allow references to surrounding object from anonymous
146 * objects during constructor call?
147 */
148 boolean allowAnonOuterThis;
150 /**
151 * Switch: warn about use of variable before declaration?
152 * RFE: 6425594
153 */
154 boolean useBeforeDeclarationWarning;
156 /** Check kind and type of given tree against protokind and prototype.
157 * If check succeeds, store type in tree and return it.
158 * If check fails, store errType in tree and return it.
159 * No checks are performed if the prototype is a method type.
160 * Its not necessary in this case since we know that kind and type
161 * are correct.
162 *
163 * @param tree The tree whose kind and type is checked
164 * @param owntype The computed type of the tree
165 * @param ownkind The computed kind of the tree
166 * @param pkind The expected kind (or: protokind) of the tree
167 * @param pt The expected type (or: prototype) of the tree
168 */
169 Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
170 if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
171 if ((ownkind & ~pkind) == 0) {
172 owntype = chk.checkType(tree.pos(), owntype, pt);
173 } else {
174 log.error(tree.pos(), "unexpected.type",
175 Resolve.kindNames(pkind),
176 Resolve.kindName(ownkind));
177 owntype = syms.errType;
178 }
179 }
180 tree.type = owntype;
181 return owntype;
182 }
184 /** Is given blank final variable assignable, i.e. in a scope where it
185 * may be assigned to even though it is final?
186 * @param v The blank final variable.
187 * @param env The current environment.
188 */
189 boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
190 Symbol owner = env.info.scope.owner;
191 // owner refers to the innermost variable, method or
192 // initializer block declaration at this point.
193 return
194 v.owner == owner
195 ||
196 ((owner.name == names.init || // i.e. we are in a constructor
197 owner.kind == VAR || // i.e. we are in a variable initializer
198 (owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
199 &&
200 v.owner == owner.owner
201 &&
202 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
203 }
205 /** Check that variable can be assigned to.
206 * @param pos The current source code position.
207 * @param v The assigned varaible
208 * @param base If the variable is referred to in a Select, the part
209 * to the left of the `.', null otherwise.
210 * @param env The current environment.
211 */
212 void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
213 if ((v.flags() & FINAL) != 0 &&
214 ((v.flags() & HASINIT) != 0
215 ||
216 !((base == null ||
217 (base.getTag() == JCTree.IDENT && TreeInfo.name(base) == names._this)) &&
218 isAssignableAsBlankFinal(v, env)))) {
219 log.error(pos, "cant.assign.val.to.final.var", v);
220 }
221 }
223 /** Does tree represent a static reference to an identifier?
224 * It is assumed that tree is either a SELECT or an IDENT.
225 * We have to weed out selects from non-type names here.
226 * @param tree The candidate tree.
227 */
228 boolean isStaticReference(JCTree tree) {
229 if (tree.getTag() == JCTree.SELECT) {
230 Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
231 if (lsym == null || lsym.kind != TYP) {
232 return false;
233 }
234 }
235 return true;
236 }
238 /** Is this symbol a type?
239 */
240 static boolean isType(Symbol sym) {
241 return sym != null && sym.kind == TYP;
242 }
244 /** The current `this' symbol.
245 * @param env The current environment.
246 */
247 Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
248 return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
249 }
251 /** Attribute a parsed identifier.
252 * @param tree Parsed identifier name
253 * @param topLevel The toplevel to use
254 */
255 public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
256 Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
257 localEnv.enclClass = make.ClassDef(make.Modifiers(0),
258 syms.errSymbol.name,
259 null, null, null, null);
260 localEnv.enclClass.sym = syms.errSymbol;
261 return tree.accept(identAttributer, localEnv);
262 }
263 // where
264 private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
265 private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
266 @Override
267 public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
268 Symbol site = visit(node.getExpression(), env);
269 if (site.kind == ERR)
270 return site;
271 Name name = (Name)node.getIdentifier();
272 if (site.kind == PCK) {
273 env.toplevel.packge = (PackageSymbol)site;
274 return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
275 } else {
276 env.enclClass.sym = (ClassSymbol)site;
277 return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
278 }
279 }
281 @Override
282 public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
283 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
284 }
285 }
287 public Type coerce(Type etype, Type ttype) {
288 return cfolder.coerce(etype, ttype);
289 }
291 public Type attribType(JCTree node, TypeSymbol sym) {
292 Env<AttrContext> env = enter.typeEnvs.get(sym);
293 Env<AttrContext> localEnv = env.dup(node, env.info.dup());
294 return attribTree(node, localEnv, Kinds.TYP, Type.noType);
295 }
297 public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
298 breakTree = tree;
299 JavaFileObject prev = log.useSource(null);
300 try {
301 attribExpr(expr, env);
302 } catch (BreakAttr b) {
303 return b.env;
304 } finally {
305 breakTree = null;
306 log.useSource(prev);
307 }
308 return env;
309 }
311 public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
312 breakTree = tree;
313 JavaFileObject prev = log.useSource(null);
314 try {
315 attribStat(stmt, env);
316 } catch (BreakAttr b) {
317 return b.env;
318 } finally {
319 breakTree = null;
320 log.useSource(prev);
321 }
322 return env;
323 }
325 private JCTree breakTree = null;
327 private static class BreakAttr extends RuntimeException {
328 static final long serialVersionUID = -6924771130405446405L;
329 private Env<AttrContext> env;
330 private BreakAttr(Env<AttrContext> env) {
331 this.env = env;
332 }
333 }
336 /* ************************************************************************
337 * Visitor methods
338 *************************************************************************/
340 /** Visitor argument: the current environment.
341 */
342 Env<AttrContext> env;
344 /** Visitor argument: the currently expected proto-kind.
345 */
346 int pkind;
348 /** Visitor argument: the currently expected proto-type.
349 */
350 Type pt;
352 /** Visitor result: the computed type.
353 */
354 Type result;
356 /** Visitor method: attribute a tree, catching any completion failure
357 * exceptions. Return the tree's type.
358 *
359 * @param tree The tree to be visited.
360 * @param env The environment visitor argument.
361 * @param pkind The protokind visitor argument.
362 * @param pt The prototype visitor argument.
363 */
364 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) {
365 Env<AttrContext> prevEnv = this.env;
366 int prevPkind = this.pkind;
367 Type prevPt = this.pt;
368 try {
369 this.env = env;
370 this.pkind = pkind;
371 this.pt = pt;
372 tree.accept(this);
373 if (tree == breakTree)
374 throw new BreakAttr(env);
375 return result;
376 } catch (CompletionFailure ex) {
377 tree.type = syms.errType;
378 return chk.completionError(tree.pos(), ex);
379 } finally {
380 this.env = prevEnv;
381 this.pkind = prevPkind;
382 this.pt = prevPt;
383 }
384 }
386 /** Derived visitor method: attribute an expression tree.
387 */
388 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
389 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
390 }
392 /** Derived visitor method: attribute an expression tree with
393 * no constraints on the computed type.
394 */
395 Type attribExpr(JCTree tree, Env<AttrContext> env) {
396 return attribTree(tree, env, VAL, Type.noType);
397 }
399 /** Derived visitor method: attribute a type tree.
400 */
401 Type attribType(JCTree tree, Env<AttrContext> env) {
402 Type result = attribTree(tree, env, TYP, Type.noType);
403 return result;
404 }
406 /** Derived visitor method: attribute a statement or definition tree.
407 */
408 public Type attribStat(JCTree tree, Env<AttrContext> env) {
409 return attribTree(tree, env, NIL, Type.noType);
410 }
412 /** Attribute a list of expressions, returning a list of types.
413 */
414 List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
415 ListBuffer<Type> ts = new ListBuffer<Type>();
416 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
417 ts.append(attribExpr(l.head, env, pt));
418 return ts.toList();
419 }
421 /** Attribute a list of statements, returning nothing.
422 */
423 <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
424 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
425 attribStat(l.head, env);
426 }
428 /** Attribute the arguments in a method call, returning a list of types.
429 */
430 List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
431 ListBuffer<Type> argtypes = new ListBuffer<Type>();
432 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
433 argtypes.append(chk.checkNonVoid(
434 l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly))));
435 return argtypes.toList();
436 }
438 /** Attribute a type argument list, returning a list of types.
439 */
440 List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
441 ListBuffer<Type> argtypes = new ListBuffer<Type>();
442 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
443 argtypes.append(chk.checkRefType(l.head.pos(), attribType(l.head, env)));
444 return argtypes.toList();
445 }
448 /**
449 * Attribute type variables (of generic classes or methods).
450 * Compound types are attributed later in attribBounds.
451 * @param typarams the type variables to enter
452 * @param env the current environment
453 */
454 void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
455 for (JCTypeParameter tvar : typarams) {
456 TypeVar a = (TypeVar)tvar.type;
457 if (!tvar.bounds.isEmpty()) {
458 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
459 for (JCExpression bound : tvar.bounds.tail)
460 bounds = bounds.prepend(attribType(bound, env));
461 types.setBounds(a, bounds.reverse());
462 } else {
463 // if no bounds are given, assume a single bound of
464 // java.lang.Object.
465 types.setBounds(a, List.of(syms.objectType));
466 }
467 }
468 }
470 void attribBounds(List<JCTypeParameter> typarams, Env<AttrContext> env) {
471 for (JCTypeParameter tvar : typarams)
472 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
473 attribStats(typarams, env);
474 for (JCTypeParameter typaram : typarams) {
475 Type bound = typaram.type.getUpperBound();
476 if (bound != null && bound.tsym instanceof ClassSymbol) {
477 ClassSymbol c = (ClassSymbol)bound.tsym;
478 if ((c.flags_field & COMPOUND) != 0) {
479 assert (c.flags_field & UNATTRIBUTED) != 0 : c;
480 attribClass(typaram.pos(), c);
481 }
482 }
483 }
484 }
486 /**
487 * Attribute the type references in a list of annotations.
488 */
489 void attribAnnotationTypes(List<JCAnnotation> annotations,
490 Env<AttrContext> env) {
491 for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
492 JCAnnotation a = al.head;
493 attribType(a.annotationType, env);
494 }
495 }
497 /** Attribute type reference in an `extends' or `implements' clause.
498 *
499 * @param tree The tree making up the type reference.
500 * @param env The environment current at the reference.
501 * @param classExpected true if only a class is expected here.
502 * @param interfaceExpected true if only an interface is expected here.
503 */
504 Type attribBase(JCTree tree,
505 Env<AttrContext> env,
506 boolean classExpected,
507 boolean interfaceExpected,
508 boolean checkExtensible) {
509 Type t = attribType(tree, env);
510 return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
511 }
512 Type checkBase(Type t,
513 JCTree tree,
514 Env<AttrContext> env,
515 boolean classExpected,
516 boolean interfaceExpected,
517 boolean checkExtensible) {
518 if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
519 // check that type variable is already visible
520 if (t.getUpperBound() == null) {
521 log.error(tree.pos(), "illegal.forward.ref");
522 return syms.errType;
523 }
524 } else {
525 t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
526 }
527 if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
528 log.error(tree.pos(), "intf.expected.here");
529 // return errType is necessary since otherwise there might
530 // be undetected cycles which cause attribution to loop
531 return syms.errType;
532 } else if (checkExtensible &&
533 classExpected &&
534 (t.tsym.flags() & INTERFACE) != 0) {
535 log.error(tree.pos(), "no.intf.expected.here");
536 return syms.errType;
537 }
538 if (checkExtensible &&
539 ((t.tsym.flags() & FINAL) != 0)) {
540 log.error(tree.pos(),
541 "cant.inherit.from.final", t.tsym);
542 }
543 chk.checkNonCyclic(tree.pos(), t);
544 return t;
545 }
547 public void visitClassDef(JCClassDecl tree) {
548 // Local classes have not been entered yet, so we need to do it now:
549 if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
550 enter.classEnter(tree, env);
552 ClassSymbol c = tree.sym;
553 if (c == null) {
554 // exit in case something drastic went wrong during enter.
555 result = null;
556 } else {
557 // make sure class has been completed:
558 c.complete();
560 // If this class appears as an anonymous class
561 // in a superclass constructor call where
562 // no explicit outer instance is given,
563 // disable implicit outer instance from being passed.
564 // (This would be an illegal access to "this before super").
565 if (env.info.isSelfCall &&
566 env.tree.getTag() == JCTree.NEWCLASS &&
567 ((JCNewClass) env.tree).encl == null)
568 {
569 c.flags_field |= NOOUTERTHIS;
570 }
571 attribClass(tree.pos(), c);
572 result = tree.type = c.type;
573 }
574 }
576 public void visitMethodDef(JCMethodDecl tree) {
577 MethodSymbol m = tree.sym;
579 Lint lint = env.info.lint.augment(m.attributes_field, m.flags());
580 Lint prevLint = chk.setLint(lint);
581 try {
582 chk.checkDeprecatedAnnotation(tree.pos(), m);
584 attribBounds(tree.typarams, env);
586 // If we override any other methods, check that we do so properly.
587 // JLS ???
588 chk.checkOverride(tree, m);
590 // Create a new environment with local scope
591 // for attributing the method.
592 Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
594 localEnv.info.lint = lint;
596 // Enter all type parameters into the local method scope.
597 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
598 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
600 ClassSymbol owner = env.enclClass.sym;
601 if ((owner.flags() & ANNOTATION) != 0 &&
602 tree.params.nonEmpty())
603 log.error(tree.params.head.pos(),
604 "intf.annotation.members.cant.have.params");
606 // Attribute all value parameters.
607 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
608 attribStat(l.head, localEnv);
609 }
611 // Check that type parameters are well-formed.
612 chk.validateTypeParams(tree.typarams);
613 if ((owner.flags() & ANNOTATION) != 0 &&
614 tree.typarams.nonEmpty())
615 log.error(tree.typarams.head.pos(),
616 "intf.annotation.members.cant.have.type.params");
618 // Check that result type is well-formed.
619 chk.validate(tree.restype);
620 if ((owner.flags() & ANNOTATION) != 0)
621 chk.validateAnnotationType(tree.restype);
623 if ((owner.flags() & ANNOTATION) != 0)
624 chk.validateAnnotationMethod(tree.pos(), m);
626 // Check that all exceptions mentioned in the throws clause extend
627 // java.lang.Throwable.
628 if ((owner.flags() & ANNOTATION) != 0 && tree.thrown.nonEmpty())
629 log.error(tree.thrown.head.pos(),
630 "throws.not.allowed.in.intf.annotation");
631 for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
632 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
634 if (tree.body == null) {
635 // Empty bodies are only allowed for
636 // abstract, native, or interface methods, or for methods
637 // in a retrofit signature class.
638 if ((owner.flags() & INTERFACE) == 0 &&
639 (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 &&
640 !relax)
641 log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
642 if (tree.defaultValue != null) {
643 if ((owner.flags() & ANNOTATION) == 0)
644 log.error(tree.pos(),
645 "default.allowed.in.intf.annotation.member");
646 }
647 } else if ((owner.flags() & INTERFACE) != 0) {
648 log.error(tree.body.pos(), "intf.meth.cant.have.body");
649 } else if ((tree.mods.flags & ABSTRACT) != 0) {
650 log.error(tree.pos(), "abstract.meth.cant.have.body");
651 } else if ((tree.mods.flags & NATIVE) != 0) {
652 log.error(tree.pos(), "native.meth.cant.have.body");
653 } else {
654 // Add an implicit super() call unless an explicit call to
655 // super(...) or this(...) is given
656 // or we are compiling class java.lang.Object.
657 if (tree.name == names.init && owner.type != syms.objectType) {
658 JCBlock body = tree.body;
659 if (body.stats.isEmpty() ||
660 !TreeInfo.isSelfCall(body.stats.head)) {
661 body.stats = body.stats.
662 prepend(memberEnter.SuperCall(make.at(body.pos),
663 List.<Type>nil(),
664 List.<JCVariableDecl>nil(),
665 false));
666 } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
667 (tree.mods.flags & GENERATEDCONSTR) == 0 &&
668 TreeInfo.isSuperCall(body.stats.head)) {
669 // enum constructors are not allowed to call super
670 // directly, so make sure there aren't any super calls
671 // in enum constructors, except in the compiler
672 // generated one.
673 log.error(tree.body.stats.head.pos(),
674 "call.to.super.not.allowed.in.enum.ctor",
675 env.enclClass.sym);
676 }
677 }
679 // Attribute method body.
680 attribStat(tree.body, localEnv);
681 }
682 localEnv.info.scope.leave();
683 result = tree.type = m.type;
684 chk.validateAnnotations(tree.mods.annotations, m);
686 }
687 finally {
688 chk.setLint(prevLint);
689 }
690 }
692 public void visitVarDef(JCVariableDecl tree) {
693 // Local variables have not been entered yet, so we need to do it now:
694 if (env.info.scope.owner.kind == MTH) {
695 if (tree.sym != null) {
696 // parameters have already been entered
697 env.info.scope.enter(tree.sym);
698 } else {
699 memberEnter.memberEnter(tree, env);
700 annotate.flush();
701 }
702 }
704 // Check that the variable's declared type is well-formed.
705 chk.validate(tree.vartype);
707 VarSymbol v = tree.sym;
708 Lint lint = env.info.lint.augment(v.attributes_field, v.flags());
709 Lint prevLint = chk.setLint(lint);
711 try {
712 chk.checkDeprecatedAnnotation(tree.pos(), v);
714 if (tree.init != null) {
715 if ((v.flags_field & FINAL) != 0 && tree.init.getTag() != JCTree.NEWCLASS) {
716 // In this case, `v' is final. Ensure that it's initializer is
717 // evaluated.
718 v.getConstValue(); // ensure initializer is evaluated
719 } else {
720 // Attribute initializer in a new environment
721 // with the declared variable as owner.
722 // Check that initializer conforms to variable's declared type.
723 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
724 initEnv.info.lint = lint;
725 // In order to catch self-references, we set the variable's
726 // declaration position to maximal possible value, effectively
727 // marking the variable as undefined.
728 v.pos = Position.MAXPOS;
729 attribExpr(tree.init, initEnv, v.type);
730 v.pos = tree.pos;
731 }
732 }
733 result = tree.type = v.type;
734 chk.validateAnnotations(tree.mods.annotations, v);
735 }
736 finally {
737 chk.setLint(prevLint);
738 }
739 }
741 public void visitSkip(JCSkip tree) {
742 result = null;
743 }
745 public void visitBlock(JCBlock tree) {
746 if (env.info.scope.owner.kind == TYP) {
747 // Block is a static or instance initializer;
748 // let the owner of the environment be a freshly
749 // created BLOCK-method.
750 Env<AttrContext> localEnv =
751 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
752 localEnv.info.scope.owner =
753 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
754 env.info.scope.owner);
755 if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
756 attribStats(tree.stats, localEnv);
757 } else {
758 // Create a new local environment with a local scope.
759 Env<AttrContext> localEnv =
760 env.dup(tree, env.info.dup(env.info.scope.dup()));
761 attribStats(tree.stats, localEnv);
762 localEnv.info.scope.leave();
763 }
764 result = null;
765 }
767 public void visitDoLoop(JCDoWhileLoop tree) {
768 attribStat(tree.body, env.dup(tree));
769 attribExpr(tree.cond, env, syms.booleanType);
770 result = null;
771 }
773 public void visitWhileLoop(JCWhileLoop tree) {
774 attribExpr(tree.cond, env, syms.booleanType);
775 attribStat(tree.body, env.dup(tree));
776 result = null;
777 }
779 public void visitForLoop(JCForLoop tree) {
780 Env<AttrContext> loopEnv =
781 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
782 attribStats(tree.init, loopEnv);
783 if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
784 loopEnv.tree = tree; // before, we were not in loop!
785 attribStats(tree.step, loopEnv);
786 attribStat(tree.body, loopEnv);
787 loopEnv.info.scope.leave();
788 result = null;
789 }
791 public void visitForeachLoop(JCEnhancedForLoop tree) {
792 Env<AttrContext> loopEnv =
793 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
794 attribStat(tree.var, loopEnv);
795 Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
796 chk.checkNonVoid(tree.pos(), exprType);
797 Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
798 if (elemtype == null) {
799 // or perhaps expr implements Iterable<T>?
800 Type base = types.asSuper(exprType, syms.iterableType.tsym);
801 if (base == null) {
802 log.error(tree.expr.pos(), "foreach.not.applicable.to.type");
803 elemtype = syms.errType;
804 } else {
805 List<Type> iterableParams = base.allparams();
806 elemtype = iterableParams.isEmpty()
807 ? syms.objectType
808 : types.upperBound(iterableParams.head);
809 }
810 }
811 chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
812 loopEnv.tree = tree; // before, we were not in loop!
813 attribStat(tree.body, loopEnv);
814 loopEnv.info.scope.leave();
815 result = null;
816 }
818 public void visitLabelled(JCLabeledStatement tree) {
819 // Check that label is not used in an enclosing statement
820 Env<AttrContext> env1 = env;
821 while (env1 != null && env1.tree.getTag() != JCTree.CLASSDEF) {
822 if (env1.tree.getTag() == JCTree.LABELLED &&
823 ((JCLabeledStatement) env1.tree).label == tree.label) {
824 log.error(tree.pos(), "label.already.in.use",
825 tree.label);
826 break;
827 }
828 env1 = env1.next;
829 }
831 attribStat(tree.body, env.dup(tree));
832 result = null;
833 }
835 public void visitSwitch(JCSwitch tree) {
836 Type seltype = attribExpr(tree.selector, env);
838 Env<AttrContext> switchEnv =
839 env.dup(tree, env.info.dup(env.info.scope.dup()));
841 boolean enumSwitch =
842 allowEnums &&
843 (seltype.tsym.flags() & Flags.ENUM) != 0;
844 if (!enumSwitch)
845 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
847 // Attribute all cases and
848 // check that there are no duplicate case labels or default clauses.
849 Set<Object> labels = new HashSet<Object>(); // The set of case labels.
850 boolean hasDefault = false; // Is there a default label?
851 for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
852 JCCase c = l.head;
853 Env<AttrContext> caseEnv =
854 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
855 if (c.pat != null) {
856 if (enumSwitch) {
857 Symbol sym = enumConstant(c.pat, seltype);
858 if (sym == null) {
859 log.error(c.pat.pos(), "enum.const.req");
860 } else if (!labels.add(sym)) {
861 log.error(c.pos(), "duplicate.case.label");
862 }
863 } else {
864 Type pattype = attribExpr(c.pat, switchEnv, seltype);
865 if (pattype.tag != ERROR) {
866 if (pattype.constValue() == null) {
867 log.error(c.pat.pos(), "const.expr.req");
868 } else if (labels.contains(pattype.constValue())) {
869 log.error(c.pos(), "duplicate.case.label");
870 } else {
871 labels.add(pattype.constValue());
872 }
873 }
874 }
875 } else if (hasDefault) {
876 log.error(c.pos(), "duplicate.default.label");
877 } else {
878 hasDefault = true;
879 }
880 attribStats(c.stats, caseEnv);
881 caseEnv.info.scope.leave();
882 addVars(c.stats, switchEnv.info.scope);
883 }
885 switchEnv.info.scope.leave();
886 result = null;
887 }
888 // where
889 /** Add any variables defined in stats to the switch scope. */
890 private static void addVars(List<JCStatement> stats, Scope switchScope) {
891 for (;stats.nonEmpty(); stats = stats.tail) {
892 JCTree stat = stats.head;
893 if (stat.getTag() == JCTree.VARDEF)
894 switchScope.enter(((JCVariableDecl) stat).sym);
895 }
896 }
897 // where
898 /** Return the selected enumeration constant symbol, or null. */
899 private Symbol enumConstant(JCTree tree, Type enumType) {
900 if (tree.getTag() != JCTree.IDENT) {
901 log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
902 return syms.errSymbol;
903 }
904 JCIdent ident = (JCIdent)tree;
905 Name name = ident.name;
906 for (Scope.Entry e = enumType.tsym.members().lookup(name);
907 e.scope != null; e = e.next()) {
908 if (e.sym.kind == VAR) {
909 Symbol s = ident.sym = e.sym;
910 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
911 ident.type = s.type;
912 return ((s.flags_field & Flags.ENUM) == 0)
913 ? null : s;
914 }
915 }
916 return null;
917 }
919 public void visitSynchronized(JCSynchronized tree) {
920 chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
921 attribStat(tree.body, env);
922 result = null;
923 }
925 public void visitTry(JCTry tree) {
926 // Attribute body
927 attribStat(tree.body, env.dup(tree, env.info.dup()));
929 // Attribute catch clauses
930 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
931 JCCatch c = l.head;
932 Env<AttrContext> catchEnv =
933 env.dup(c, env.info.dup(env.info.scope.dup()));
934 Type ctype = attribStat(c.param, catchEnv);
935 if (c.param.type.tsym.kind == Kinds.VAR) {
936 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
937 }
938 chk.checkType(c.param.vartype.pos(),
939 chk.checkClassType(c.param.vartype.pos(), ctype),
940 syms.throwableType);
941 attribStat(c.body, catchEnv);
942 catchEnv.info.scope.leave();
943 }
945 // Attribute finalizer
946 if (tree.finalizer != null) attribStat(tree.finalizer, env);
947 result = null;
948 }
950 public void visitConditional(JCConditional tree) {
951 attribExpr(tree.cond, env, syms.booleanType);
952 attribExpr(tree.truepart, env);
953 attribExpr(tree.falsepart, env);
954 result = check(tree,
955 capture(condType(tree.pos(), tree.cond.type,
956 tree.truepart.type, tree.falsepart.type)),
957 VAL, pkind, pt);
958 }
959 //where
960 /** Compute the type of a conditional expression, after
961 * checking that it exists. See Spec 15.25.
962 *
963 * @param pos The source position to be used for
964 * error diagnostics.
965 * @param condtype The type of the expression's condition.
966 * @param thentype The type of the expression's then-part.
967 * @param elsetype The type of the expression's else-part.
968 */
969 private Type condType(DiagnosticPosition pos,
970 Type condtype,
971 Type thentype,
972 Type elsetype) {
973 Type ctype = condType1(pos, condtype, thentype, elsetype);
975 // If condition and both arms are numeric constants,
976 // evaluate at compile-time.
977 return ((condtype.constValue() != null) &&
978 (thentype.constValue() != null) &&
979 (elsetype.constValue() != null))
980 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
981 : ctype;
982 }
983 /** Compute the type of a conditional expression, after
984 * checking that it exists. Does not take into
985 * account the special case where condition and both arms
986 * are constants.
987 *
988 * @param pos The source position to be used for error
989 * diagnostics.
990 * @param condtype The type of the expression's condition.
991 * @param thentype The type of the expression's then-part.
992 * @param elsetype The type of the expression's else-part.
993 */
994 private Type condType1(DiagnosticPosition pos, Type condtype,
995 Type thentype, Type elsetype) {
996 // If same type, that is the result
997 if (types.isSameType(thentype, elsetype))
998 return thentype.baseType();
1000 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1001 ? thentype : types.unboxedType(thentype);
1002 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1003 ? elsetype : types.unboxedType(elsetype);
1005 // Otherwise, if both arms can be converted to a numeric
1006 // type, return the least numeric type that fits both arms
1007 // (i.e. return larger of the two, or return int if one
1008 // arm is short, the other is char).
1009 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1010 // If one arm has an integer subrange type (i.e., byte,
1011 // short, or char), and the other is an integer constant
1012 // that fits into the subrange, return the subrange type.
1013 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1014 types.isAssignable(elseUnboxed, thenUnboxed))
1015 return thenUnboxed.baseType();
1016 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1017 types.isAssignable(thenUnboxed, elseUnboxed))
1018 return elseUnboxed.baseType();
1020 for (int i = BYTE; i < VOID; i++) {
1021 Type candidate = syms.typeOfTag[i];
1022 if (types.isSubtype(thenUnboxed, candidate) &&
1023 types.isSubtype(elseUnboxed, candidate))
1024 return candidate;
1025 }
1026 }
1028 // Those were all the cases that could result in a primitive
1029 if (allowBoxing) {
1030 if (thentype.isPrimitive())
1031 thentype = types.boxedClass(thentype).type;
1032 if (elsetype.isPrimitive())
1033 elsetype = types.boxedClass(elsetype).type;
1034 }
1036 if (types.isSubtype(thentype, elsetype))
1037 return elsetype.baseType();
1038 if (types.isSubtype(elsetype, thentype))
1039 return thentype.baseType();
1041 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1042 log.error(pos, "neither.conditional.subtype",
1043 thentype, elsetype);
1044 return thentype.baseType();
1045 }
1047 // both are known to be reference types. The result is
1048 // lub(thentype,elsetype). This cannot fail, as it will
1049 // always be possible to infer "Object" if nothing better.
1050 return types.lub(thentype.baseType(), elsetype.baseType());
1051 }
1053 public void visitIf(JCIf tree) {
1054 attribExpr(tree.cond, env, syms.booleanType);
1055 attribStat(tree.thenpart, env);
1056 if (tree.elsepart != null)
1057 attribStat(tree.elsepart, env);
1058 chk.checkEmptyIf(tree);
1059 result = null;
1060 }
1062 public void visitExec(JCExpressionStatement tree) {
1063 attribExpr(tree.expr, env);
1064 result = null;
1065 }
1067 public void visitBreak(JCBreak tree) {
1068 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1069 result = null;
1070 }
1072 public void visitContinue(JCContinue tree) {
1073 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1074 result = null;
1075 }
1076 //where
1077 /** Return the target of a break or continue statement, if it exists,
1078 * report an error if not.
1079 * Note: The target of a labelled break or continue is the
1080 * (non-labelled) statement tree referred to by the label,
1081 * not the tree representing the labelled statement itself.
1082 *
1083 * @param pos The position to be used for error diagnostics
1084 * @param tag The tag of the jump statement. This is either
1085 * Tree.BREAK or Tree.CONTINUE.
1086 * @param label The label of the jump statement, or null if no
1087 * label is given.
1088 * @param env The environment current at the jump statement.
1089 */
1090 private JCTree findJumpTarget(DiagnosticPosition pos,
1091 int tag,
1092 Name label,
1093 Env<AttrContext> env) {
1094 // Search environments outwards from the point of jump.
1095 Env<AttrContext> env1 = env;
1096 LOOP:
1097 while (env1 != null) {
1098 switch (env1.tree.getTag()) {
1099 case JCTree.LABELLED:
1100 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1101 if (label == labelled.label) {
1102 // If jump is a continue, check that target is a loop.
1103 if (tag == JCTree.CONTINUE) {
1104 if (labelled.body.getTag() != JCTree.DOLOOP &&
1105 labelled.body.getTag() != JCTree.WHILELOOP &&
1106 labelled.body.getTag() != JCTree.FORLOOP &&
1107 labelled.body.getTag() != JCTree.FOREACHLOOP)
1108 log.error(pos, "not.loop.label", label);
1109 // Found labelled statement target, now go inwards
1110 // to next non-labelled tree.
1111 return TreeInfo.referencedStatement(labelled);
1112 } else {
1113 return labelled;
1114 }
1115 }
1116 break;
1117 case JCTree.DOLOOP:
1118 case JCTree.WHILELOOP:
1119 case JCTree.FORLOOP:
1120 case JCTree.FOREACHLOOP:
1121 if (label == null) return env1.tree;
1122 break;
1123 case JCTree.SWITCH:
1124 if (label == null && tag == JCTree.BREAK) return env1.tree;
1125 break;
1126 case JCTree.METHODDEF:
1127 case JCTree.CLASSDEF:
1128 break LOOP;
1129 default:
1130 }
1131 env1 = env1.next;
1132 }
1133 if (label != null)
1134 log.error(pos, "undef.label", label);
1135 else if (tag == JCTree.CONTINUE)
1136 log.error(pos, "cont.outside.loop");
1137 else
1138 log.error(pos, "break.outside.switch.loop");
1139 return null;
1140 }
1142 public void visitReturn(JCReturn tree) {
1143 // Check that there is an enclosing method which is
1144 // nested within than the enclosing class.
1145 if (env.enclMethod == null ||
1146 env.enclMethod.sym.owner != env.enclClass.sym) {
1147 log.error(tree.pos(), "ret.outside.meth");
1149 } else {
1150 // Attribute return expression, if it exists, and check that
1151 // it conforms to result type of enclosing method.
1152 Symbol m = env.enclMethod.sym;
1153 if (m.type.getReturnType().tag == VOID) {
1154 if (tree.expr != null)
1155 log.error(tree.expr.pos(),
1156 "cant.ret.val.from.meth.decl.void");
1157 } else if (tree.expr == null) {
1158 log.error(tree.pos(), "missing.ret.val");
1159 } else {
1160 attribExpr(tree.expr, env, m.type.getReturnType());
1161 }
1162 }
1163 result = null;
1164 }
1166 public void visitThrow(JCThrow tree) {
1167 attribExpr(tree.expr, env, syms.throwableType);
1168 result = null;
1169 }
1171 public void visitAssert(JCAssert tree) {
1172 attribExpr(tree.cond, env, syms.booleanType);
1173 if (tree.detail != null) {
1174 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1175 }
1176 result = null;
1177 }
1179 /** Visitor method for method invocations.
1180 * NOTE: The method part of an application will have in its type field
1181 * the return type of the method, not the method's type itself!
1182 */
1183 public void visitApply(JCMethodInvocation tree) {
1184 // The local environment of a method application is
1185 // a new environment nested in the current one.
1186 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1188 // The types of the actual method arguments.
1189 List<Type> argtypes;
1191 // The types of the actual method type arguments.
1192 List<Type> typeargtypes = null;
1194 Name methName = TreeInfo.name(tree.meth);
1196 boolean isConstructorCall =
1197 methName == names._this || methName == names._super;
1199 if (isConstructorCall) {
1200 // We are seeing a ...this(...) or ...super(...) call.
1201 // Check that this is the first statement in a constructor.
1202 if (checkFirstConstructorStat(tree, env)) {
1204 // Record the fact
1205 // that this is a constructor call (using isSelfCall).
1206 localEnv.info.isSelfCall = true;
1208 // Attribute arguments, yielding list of argument types.
1209 argtypes = attribArgs(tree.args, localEnv);
1210 typeargtypes = attribTypes(tree.typeargs, localEnv);
1212 // Variable `site' points to the class in which the called
1213 // constructor is defined.
1214 Type site = env.enclClass.sym.type;
1215 if (methName == names._super) {
1216 if (site == syms.objectType) {
1217 log.error(tree.meth.pos(), "no.superclass", site);
1218 site = syms.errType;
1219 } else {
1220 site = types.supertype(site);
1221 }
1222 }
1224 if (site.tag == CLASS) {
1225 if (site.getEnclosingType().tag == CLASS) {
1226 // we are calling a nested class
1228 if (tree.meth.getTag() == JCTree.SELECT) {
1229 JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1231 // We are seeing a prefixed call, of the form
1232 // <expr>.super(...).
1233 // Check that the prefix expression conforms
1234 // to the outer instance type of the class.
1235 chk.checkRefType(qualifier.pos(),
1236 attribExpr(qualifier, localEnv,
1237 site.getEnclosingType()));
1238 } else if (methName == names._super) {
1239 // qualifier omitted; check for existence
1240 // of an appropriate implicit qualifier.
1241 rs.resolveImplicitThis(tree.meth.pos(),
1242 localEnv, site);
1243 }
1244 } else if (tree.meth.getTag() == JCTree.SELECT) {
1245 log.error(tree.meth.pos(), "illegal.qual.not.icls",
1246 site.tsym);
1247 }
1249 // if we're calling a java.lang.Enum constructor,
1250 // prefix the implicit String and int parameters
1251 if (site.tsym == syms.enumSym && allowEnums)
1252 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1254 // Resolve the called constructor under the assumption
1255 // that we are referring to a superclass instance of the
1256 // current instance (JLS ???).
1257 boolean selectSuperPrev = localEnv.info.selectSuper;
1258 localEnv.info.selectSuper = true;
1259 localEnv.info.varArgs = false;
1260 Symbol sym = rs.resolveConstructor(
1261 tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1262 localEnv.info.selectSuper = selectSuperPrev;
1264 // Set method symbol to resolved constructor...
1265 TreeInfo.setSymbol(tree.meth, sym);
1267 // ...and check that it is legal in the current context.
1268 // (this will also set the tree's type)
1269 Type mpt = newMethTemplate(argtypes, typeargtypes);
1270 checkId(tree.meth, site, sym, localEnv, MTH,
1271 mpt, tree.varargsElement != null);
1272 }
1273 // Otherwise, `site' is an error type and we do nothing
1274 }
1275 result = tree.type = syms.voidType;
1276 } else {
1277 // Otherwise, we are seeing a regular method call.
1278 // Attribute the arguments, yielding list of argument types, ...
1279 argtypes = attribArgs(tree.args, localEnv);
1280 typeargtypes = attribTypes(tree.typeargs, localEnv);
1282 // ... and attribute the method using as a prototype a methodtype
1283 // whose formal argument types is exactly the list of actual
1284 // arguments (this will also set the method symbol).
1285 Type mpt = newMethTemplate(argtypes, typeargtypes);
1286 localEnv.info.varArgs = false;
1287 Type mtype = attribExpr(tree.meth, localEnv, mpt);
1288 if (localEnv.info.varArgs)
1289 assert mtype.isErroneous() || tree.varargsElement != null;
1291 // Compute the result type.
1292 Type restype = mtype.getReturnType();
1293 assert restype.tag != WILDCARD : mtype;
1295 // as a special case, array.clone() has a result that is
1296 // the same as static type of the array being cloned
1297 if (tree.meth.getTag() == JCTree.SELECT &&
1298 allowCovariantReturns &&
1299 methName == names.clone &&
1300 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1301 restype = ((JCFieldAccess) tree.meth).selected.type;
1303 // as a special case, x.getClass() has type Class<? extends |X|>
1304 if (allowGenerics &&
1305 methName == names.getClass && tree.args.isEmpty()) {
1306 Type qualifier = (tree.meth.getTag() == JCTree.SELECT)
1307 ? ((JCFieldAccess) tree.meth).selected.type
1308 : env.enclClass.sym.type;
1309 restype = new
1310 ClassType(restype.getEnclosingType(),
1311 List.<Type>of(new WildcardType(types.erasure(qualifier),
1312 BoundKind.EXTENDS,
1313 syms.boundClass)),
1314 restype.tsym);
1315 }
1317 // Check that value of resulting type is admissible in the
1318 // current context. Also, capture the return type
1319 result = check(tree, capture(restype), VAL, pkind, pt);
1320 }
1321 chk.validate(tree.typeargs);
1322 }
1323 //where
1324 /** Check that given application node appears as first statement
1325 * in a constructor call.
1326 * @param tree The application node
1327 * @param env The environment current at the application.
1328 */
1329 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1330 JCMethodDecl enclMethod = env.enclMethod;
1331 if (enclMethod != null && enclMethod.name == names.init) {
1332 JCBlock body = enclMethod.body;
1333 if (body.stats.head.getTag() == JCTree.EXEC &&
1334 ((JCExpressionStatement) body.stats.head).expr == tree)
1335 return true;
1336 }
1337 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1338 TreeInfo.name(tree.meth));
1339 return false;
1340 }
1342 /** Obtain a method type with given argument types.
1343 */
1344 Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
1345 MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
1346 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1347 }
1349 public void visitNewClass(JCNewClass tree) {
1350 Type owntype = syms.errType;
1352 // The local environment of a class creation is
1353 // a new environment nested in the current one.
1354 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1356 // The anonymous inner class definition of the new expression,
1357 // if one is defined by it.
1358 JCClassDecl cdef = tree.def;
1360 // If enclosing class is given, attribute it, and
1361 // complete class name to be fully qualified
1362 JCExpression clazz = tree.clazz; // Class field following new
1363 JCExpression clazzid = // Identifier in class field
1364 (clazz.getTag() == JCTree.TYPEAPPLY)
1365 ? ((JCTypeApply) clazz).clazz
1366 : clazz;
1368 JCExpression clazzid1 = clazzid; // The same in fully qualified form
1370 if (tree.encl != null) {
1371 // We are seeing a qualified new, of the form
1372 // <expr>.new C <...> (...) ...
1373 // In this case, we let clazz stand for the name of the
1374 // allocated class C prefixed with the type of the qualifier
1375 // expression, so that we can
1376 // resolve it with standard techniques later. I.e., if
1377 // <expr> has type T, then <expr>.new C <...> (...)
1378 // yields a clazz T.C.
1379 Type encltype = chk.checkRefType(tree.encl.pos(),
1380 attribExpr(tree.encl, env));
1381 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1382 ((JCIdent) clazzid).name);
1383 if (clazz.getTag() == JCTree.TYPEAPPLY)
1384 clazz = make.at(tree.pos).
1385 TypeApply(clazzid1,
1386 ((JCTypeApply) clazz).arguments);
1387 else
1388 clazz = clazzid1;
1389 // System.out.println(clazz + " generated.");//DEBUG
1390 }
1392 // Attribute clazz expression and store
1393 // symbol + type back into the attributed tree.
1394 Type clazztype = chk.checkClassType(
1395 tree.clazz.pos(), attribType(clazz, env), true);
1396 chk.validate(clazz);
1397 if (tree.encl != null) {
1398 // We have to work in this case to store
1399 // symbol + type back into the attributed tree.
1400 tree.clazz.type = clazztype;
1401 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1402 clazzid.type = ((JCIdent) clazzid).sym.type;
1403 if (!clazztype.isErroneous()) {
1404 if (cdef != null && clazztype.tsym.isInterface()) {
1405 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1406 } else if (clazztype.tsym.isStatic()) {
1407 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1408 }
1409 }
1410 } else if (!clazztype.tsym.isInterface() &&
1411 clazztype.getEnclosingType().tag == CLASS) {
1412 // Check for the existence of an apropos outer instance
1413 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1414 }
1416 // Attribute constructor arguments.
1417 List<Type> argtypes = attribArgs(tree.args, localEnv);
1418 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1420 // If we have made no mistakes in the class type...
1421 if (clazztype.tag == CLASS) {
1422 // Enums may not be instantiated except implicitly
1423 if (allowEnums &&
1424 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1425 (env.tree.getTag() != JCTree.VARDEF ||
1426 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1427 ((JCVariableDecl) env.tree).init != tree))
1428 log.error(tree.pos(), "enum.cant.be.instantiated");
1429 // Check that class is not abstract
1430 if (cdef == null &&
1431 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1432 log.error(tree.pos(), "abstract.cant.be.instantiated",
1433 clazztype.tsym);
1434 } else if (cdef != null && clazztype.tsym.isInterface()) {
1435 // Check that no constructor arguments are given to
1436 // anonymous classes implementing an interface
1437 if (!argtypes.isEmpty())
1438 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1440 if (!typeargtypes.isEmpty())
1441 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1443 // Error recovery: pretend no arguments were supplied.
1444 argtypes = List.nil();
1445 typeargtypes = List.nil();
1446 }
1448 // Resolve the called constructor under the assumption
1449 // that we are referring to a superclass instance of the
1450 // current instance (JLS ???).
1451 else {
1452 localEnv.info.selectSuper = cdef != null;
1453 localEnv.info.varArgs = false;
1454 tree.constructor = rs.resolveConstructor(
1455 tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
1456 Type ctorType = checkMethod(clazztype,
1457 tree.constructor,
1458 localEnv,
1459 tree.args,
1460 argtypes,
1461 typeargtypes,
1462 localEnv.info.varArgs);
1463 if (localEnv.info.varArgs)
1464 assert ctorType.isErroneous() || tree.varargsElement != null;
1465 }
1467 if (cdef != null) {
1468 // We are seeing an anonymous class instance creation.
1469 // In this case, the class instance creation
1470 // expression
1471 //
1472 // E.new <typeargs1>C<typargs2>(args) { ... }
1473 //
1474 // is represented internally as
1475 //
1476 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1477 //
1478 // This expression is then *transformed* as follows:
1479 //
1480 // (1) add a STATIC flag to the class definition
1481 // if the current environment is static
1482 // (2) add an extends or implements clause
1483 // (3) add a constructor.
1484 //
1485 // For instance, if C is a class, and ET is the type of E,
1486 // the expression
1487 //
1488 // E.new <typeargs1>C<typargs2>(args) { ... }
1489 //
1490 // is translated to (where X is a fresh name and typarams is the
1491 // parameter list of the super constructor):
1492 //
1493 // new <typeargs1>X(<*nullchk*>E, args) where
1494 // X extends C<typargs2> {
1495 // <typarams> X(ET e, args) {
1496 // e.<typeargs1>super(args)
1497 // }
1498 // ...
1499 // }
1500 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1502 if (clazztype.tsym.isInterface()) {
1503 cdef.implementing = List.of(clazz);
1504 } else {
1505 cdef.extending = clazz;
1506 }
1508 attribStat(cdef, localEnv);
1510 // If an outer instance is given,
1511 // prefix it to the constructor arguments
1512 // and delete it from the new expression
1513 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1514 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1515 argtypes = argtypes.prepend(tree.encl.type);
1516 tree.encl = null;
1517 }
1519 // Reassign clazztype and recompute constructor.
1520 clazztype = cdef.sym.type;
1521 Symbol sym = rs.resolveConstructor(
1522 tree.pos(), localEnv, clazztype, argtypes,
1523 typeargtypes, true, tree.varargsElement != null);
1524 assert sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous();
1525 tree.constructor = sym;
1526 }
1528 if (tree.constructor != null && tree.constructor.kind == MTH)
1529 owntype = clazztype;
1530 }
1531 result = check(tree, owntype, VAL, pkind, pt);
1532 chk.validate(tree.typeargs);
1533 }
1535 /** Make an attributed null check tree.
1536 */
1537 public JCExpression makeNullCheck(JCExpression arg) {
1538 // optimization: X.this is never null; skip null check
1539 Name name = TreeInfo.name(arg);
1540 if (name == names._this || name == names._super) return arg;
1542 int optag = JCTree.NULLCHK;
1543 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1544 tree.operator = syms.nullcheck;
1545 tree.type = arg.type;
1546 return tree;
1547 }
1549 public void visitNewArray(JCNewArray tree) {
1550 Type owntype = syms.errType;
1551 Type elemtype;
1552 if (tree.elemtype != null) {
1553 elemtype = attribType(tree.elemtype, env);
1554 chk.validate(tree.elemtype);
1555 owntype = elemtype;
1556 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1557 attribExpr(l.head, env, syms.intType);
1558 owntype = new ArrayType(owntype, syms.arrayClass);
1559 }
1560 } else {
1561 // we are seeing an untyped aggregate { ... }
1562 // this is allowed only if the prototype is an array
1563 if (pt.tag == ARRAY) {
1564 elemtype = types.elemtype(pt);
1565 } else {
1566 if (pt.tag != ERROR) {
1567 log.error(tree.pos(), "illegal.initializer.for.type",
1568 pt);
1569 }
1570 elemtype = syms.errType;
1571 }
1572 }
1573 if (tree.elems != null) {
1574 attribExprs(tree.elems, env, elemtype);
1575 owntype = new ArrayType(elemtype, syms.arrayClass);
1576 }
1577 if (!types.isReifiable(elemtype))
1578 log.error(tree.pos(), "generic.array.creation");
1579 result = check(tree, owntype, VAL, pkind, pt);
1580 }
1582 public void visitParens(JCParens tree) {
1583 Type owntype = attribTree(tree.expr, env, pkind, pt);
1584 result = check(tree, owntype, pkind, pkind, pt);
1585 Symbol sym = TreeInfo.symbol(tree);
1586 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1587 log.error(tree.pos(), "illegal.start.of.type");
1588 }
1590 public void visitAssign(JCAssign tree) {
1591 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1592 Type capturedType = capture(owntype);
1593 attribExpr(tree.rhs, env, owntype);
1594 result = check(tree, capturedType, VAL, pkind, pt);
1595 }
1597 public void visitAssignop(JCAssignOp tree) {
1598 // Attribute arguments.
1599 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
1600 Type operand = attribExpr(tree.rhs, env);
1601 // Find operator.
1602 Symbol operator = tree.operator = rs.resolveBinaryOperator(
1603 tree.pos(), tree.getTag() - JCTree.ASGOffset, env,
1604 owntype, operand);
1606 if (operator.kind == MTH) {
1607 chk.checkOperator(tree.pos(),
1608 (OperatorSymbol)operator,
1609 tree.getTag() - JCTree.ASGOffset,
1610 owntype,
1611 operand);
1612 if (types.isSameType(operator.type.getReturnType(), syms.stringType)) {
1613 // String assignment; make sure the lhs is a string
1614 chk.checkType(tree.lhs.pos(),
1615 owntype,
1616 syms.stringType);
1617 } else {
1618 chk.checkDivZero(tree.rhs.pos(), operator, operand);
1619 chk.checkCastable(tree.rhs.pos(),
1620 operator.type.getReturnType(),
1621 owntype);
1622 }
1623 }
1624 result = check(tree, owntype, VAL, pkind, pt);
1625 }
1627 public void visitUnary(JCUnary tree) {
1628 // Attribute arguments.
1629 Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1630 ? attribTree(tree.arg, env, VAR, Type.noType)
1631 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
1633 // Find operator.
1634 Symbol operator = tree.operator =
1635 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
1637 Type owntype = syms.errType;
1638 if (operator.kind == MTH) {
1639 owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1640 ? tree.arg.type
1641 : operator.type.getReturnType();
1642 int opc = ((OperatorSymbol)operator).opcode;
1644 // If the argument is constant, fold it.
1645 if (argtype.constValue() != null) {
1646 Type ctype = cfolder.fold1(opc, argtype);
1647 if (ctype != null) {
1648 owntype = cfolder.coerce(ctype, owntype);
1650 // Remove constant types from arguments to
1651 // conserve space. The parser will fold concatenations
1652 // of string literals; the code here also
1653 // gets rid of intermediate results when some of the
1654 // operands are constant identifiers.
1655 if (tree.arg.type.tsym == syms.stringType.tsym) {
1656 tree.arg.type = syms.stringType;
1657 }
1658 }
1659 }
1660 }
1661 result = check(tree, owntype, VAL, pkind, pt);
1662 }
1664 public void visitBinary(JCBinary tree) {
1665 // Attribute arguments.
1666 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
1667 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
1669 // Find operator.
1670 Symbol operator = tree.operator =
1671 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
1673 Type owntype = syms.errType;
1674 if (operator.kind == MTH) {
1675 owntype = operator.type.getReturnType();
1676 int opc = chk.checkOperator(tree.lhs.pos(),
1677 (OperatorSymbol)operator,
1678 tree.getTag(),
1679 left,
1680 right);
1682 // If both arguments are constants, fold them.
1683 if (left.constValue() != null && right.constValue() != null) {
1684 Type ctype = cfolder.fold2(opc, left, right);
1685 if (ctype != null) {
1686 owntype = cfolder.coerce(ctype, owntype);
1688 // Remove constant types from arguments to
1689 // conserve space. The parser will fold concatenations
1690 // of string literals; the code here also
1691 // gets rid of intermediate results when some of the
1692 // operands are constant identifiers.
1693 if (tree.lhs.type.tsym == syms.stringType.tsym) {
1694 tree.lhs.type = syms.stringType;
1695 }
1696 if (tree.rhs.type.tsym == syms.stringType.tsym) {
1697 tree.rhs.type = syms.stringType;
1698 }
1699 }
1700 }
1702 // Check that argument types of a reference ==, != are
1703 // castable to each other, (JLS???).
1704 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
1705 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
1706 log.error(tree.pos(), "incomparable.types", left, right);
1707 }
1708 }
1710 chk.checkDivZero(tree.rhs.pos(), operator, right);
1711 }
1712 result = check(tree, owntype, VAL, pkind, pt);
1713 }
1715 public void visitTypeCast(JCTypeCast tree) {
1716 Type clazztype = attribType(tree.clazz, env);
1717 Type exprtype = attribExpr(tree.expr, env, Infer.anyPoly);
1718 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1719 if (exprtype.constValue() != null)
1720 owntype = cfolder.coerce(exprtype, owntype);
1721 result = check(tree, capture(owntype), VAL, pkind, pt);
1722 }
1724 public void visitTypeTest(JCInstanceOf tree) {
1725 Type exprtype = chk.checkNullOrRefType(
1726 tree.expr.pos(), attribExpr(tree.expr, env));
1727 Type clazztype = chk.checkReifiableReferenceType(
1728 tree.clazz.pos(), attribType(tree.clazz, env));
1729 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1730 result = check(tree, syms.booleanType, VAL, pkind, pt);
1731 }
1733 public void visitIndexed(JCArrayAccess tree) {
1734 Type owntype = syms.errType;
1735 Type atype = attribExpr(tree.indexed, env);
1736 attribExpr(tree.index, env, syms.intType);
1737 if (types.isArray(atype))
1738 owntype = types.elemtype(atype);
1739 else if (atype.tag != ERROR)
1740 log.error(tree.pos(), "array.req.but.found", atype);
1741 if ((pkind & VAR) == 0) owntype = capture(owntype);
1742 result = check(tree, owntype, VAR, pkind, pt);
1743 }
1745 public void visitIdent(JCIdent tree) {
1746 Symbol sym;
1747 boolean varArgs = false;
1749 // Find symbol
1750 if (pt.tag == METHOD || pt.tag == FORALL) {
1751 // If we are looking for a method, the prototype `pt' will be a
1752 // method type with the type of the call's arguments as parameters.
1753 env.info.varArgs = false;
1754 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
1755 varArgs = env.info.varArgs;
1756 } else if (tree.sym != null && tree.sym.kind != VAR) {
1757 sym = tree.sym;
1758 } else {
1759 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
1760 }
1761 tree.sym = sym;
1763 // (1) Also find the environment current for the class where
1764 // sym is defined (`symEnv').
1765 // Only for pre-tiger versions (1.4 and earlier):
1766 // (2) Also determine whether we access symbol out of an anonymous
1767 // class in a this or super call. This is illegal for instance
1768 // members since such classes don't carry a this$n link.
1769 // (`noOuterThisPath').
1770 Env<AttrContext> symEnv = env;
1771 boolean noOuterThisPath = false;
1772 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
1773 (sym.kind & (VAR | MTH | TYP)) != 0 &&
1774 sym.owner.kind == TYP &&
1775 tree.name != names._this && tree.name != names._super) {
1777 // Find environment in which identifier is defined.
1778 while (symEnv.outer != null &&
1779 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
1780 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
1781 noOuterThisPath = !allowAnonOuterThis;
1782 symEnv = symEnv.outer;
1783 }
1784 }
1786 // If symbol is a variable, ...
1787 if (sym.kind == VAR) {
1788 VarSymbol v = (VarSymbol)sym;
1790 // ..., evaluate its initializer, if it has one, and check for
1791 // illegal forward reference.
1792 checkInit(tree, env, v, false);
1794 // If symbol is a local variable accessed from an embedded
1795 // inner class check that it is final.
1796 if (v.owner.kind == MTH &&
1797 v.owner != env.info.scope.owner &&
1798 (v.flags_field & FINAL) == 0) {
1799 log.error(tree.pos(),
1800 "local.var.accessed.from.icls.needs.final",
1801 v);
1802 }
1804 // If we are expecting a variable (as opposed to a value), check
1805 // that the variable is assignable in the current environment.
1806 if (pkind == VAR)
1807 checkAssignable(tree.pos(), v, null, env);
1808 }
1810 // In a constructor body,
1811 // if symbol is a field or instance method, check that it is
1812 // not accessed before the supertype constructor is called.
1813 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
1814 (sym.kind & (VAR | MTH)) != 0 &&
1815 sym.owner.kind == TYP &&
1816 (sym.flags() & STATIC) == 0) {
1817 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
1818 }
1819 Env<AttrContext> env1 = env;
1820 if (sym.kind != ERR && sym.owner != null && sym.owner != env1.enclClass.sym) {
1821 // If the found symbol is inaccessible, then it is
1822 // accessed through an enclosing instance. Locate this
1823 // enclosing instance:
1824 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
1825 env1 = env1.outer;
1826 }
1827 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
1828 }
1830 public void visitSelect(JCFieldAccess tree) {
1831 // Determine the expected kind of the qualifier expression.
1832 int skind = 0;
1833 if (tree.name == names._this || tree.name == names._super ||
1834 tree.name == names._class)
1835 {
1836 skind = TYP;
1837 } else {
1838 if ((pkind & PCK) != 0) skind = skind | PCK;
1839 if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
1840 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
1841 }
1843 // Attribute the qualifier expression, and determine its symbol (if any).
1844 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
1845 if ((pkind & (PCK | TYP)) == 0)
1846 site = capture(site); // Capture field access
1848 // don't allow T.class T[].class, etc
1849 if (skind == TYP) {
1850 Type elt = site;
1851 while (elt.tag == ARRAY)
1852 elt = ((ArrayType)elt).elemtype;
1853 if (elt.tag == TYPEVAR) {
1854 log.error(tree.pos(), "type.var.cant.be.deref");
1855 result = syms.errType;
1856 return;
1857 }
1858 }
1860 // If qualifier symbol is a type or `super', assert `selectSuper'
1861 // for the selection. This is relevant for determining whether
1862 // protected symbols are accessible.
1863 Symbol sitesym = TreeInfo.symbol(tree.selected);
1864 boolean selectSuperPrev = env.info.selectSuper;
1865 env.info.selectSuper =
1866 sitesym != null &&
1867 sitesym.name == names._super;
1869 // If selected expression is polymorphic, strip
1870 // type parameters and remember in env.info.tvars, so that
1871 // they can be added later (in Attr.checkId and Infer.instantiateMethod).
1872 if (tree.selected.type.tag == FORALL) {
1873 ForAll pstype = (ForAll)tree.selected.type;
1874 env.info.tvars = pstype.tvars;
1875 site = tree.selected.type = pstype.qtype;
1876 }
1878 // Determine the symbol represented by the selection.
1879 env.info.varArgs = false;
1880 Symbol sym = selectSym(tree, site, env, pt, pkind);
1881 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
1882 site = capture(site);
1883 sym = selectSym(tree, site, env, pt, pkind);
1884 }
1885 boolean varArgs = env.info.varArgs;
1886 tree.sym = sym;
1888 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR)
1889 site = capture(site.getUpperBound());
1891 // If that symbol is a variable, ...
1892 if (sym.kind == VAR) {
1893 VarSymbol v = (VarSymbol)sym;
1895 // ..., evaluate its initializer, if it has one, and check for
1896 // illegal forward reference.
1897 checkInit(tree, env, v, true);
1899 // If we are expecting a variable (as opposed to a value), check
1900 // that the variable is assignable in the current environment.
1901 if (pkind == VAR)
1902 checkAssignable(tree.pos(), v, tree.selected, env);
1903 }
1905 // Disallow selecting a type from an expression
1906 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
1907 tree.type = check(tree.selected, pt,
1908 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
1909 }
1911 if (isType(sitesym)) {
1912 if (sym.name == names._this) {
1913 // If `C' is the currently compiled class, check that
1914 // C.this' does not appear in a call to a super(...)
1915 if (env.info.isSelfCall &&
1916 site.tsym == env.enclClass.sym) {
1917 chk.earlyRefError(tree.pos(), sym);
1918 }
1919 } else {
1920 // Check if type-qualified fields or methods are static (JLS)
1921 if ((sym.flags() & STATIC) == 0 &&
1922 sym.name != names._super &&
1923 (sym.kind == VAR || sym.kind == MTH)) {
1924 rs.access(rs.new StaticError(sym),
1925 tree.pos(), site, sym.name, true);
1926 }
1927 }
1928 }
1930 // If we are selecting an instance member via a `super', ...
1931 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
1933 // Check that super-qualified symbols are not abstract (JLS)
1934 rs.checkNonAbstract(tree.pos(), sym);
1936 if (site.isRaw()) {
1937 // Determine argument types for site.
1938 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
1939 if (site1 != null) site = site1;
1940 }
1941 }
1943 env.info.selectSuper = selectSuperPrev;
1944 result = checkId(tree, site, sym, env, pkind, pt, varArgs);
1945 env.info.tvars = List.nil();
1946 }
1947 //where
1948 /** Determine symbol referenced by a Select expression,
1949 *
1950 * @param tree The select tree.
1951 * @param site The type of the selected expression,
1952 * @param env The current environment.
1953 * @param pt The current prototype.
1954 * @param pkind The expected kind(s) of the Select expression.
1955 */
1956 private Symbol selectSym(JCFieldAccess tree,
1957 Type site,
1958 Env<AttrContext> env,
1959 Type pt,
1960 int pkind) {
1961 DiagnosticPosition pos = tree.pos();
1962 Name name = tree.name;
1964 switch (site.tag) {
1965 case PACKAGE:
1966 return rs.access(
1967 rs.findIdentInPackage(env, site.tsym, name, pkind),
1968 pos, site, name, true);
1969 case ARRAY:
1970 case CLASS:
1971 if (pt.tag == METHOD || pt.tag == FORALL) {
1972 return rs.resolveQualifiedMethod(
1973 pos, env, site, name, pt.getParameterTypes(), pt.getTypeArguments());
1974 } else if (name == names._this || name == names._super) {
1975 return rs.resolveSelf(pos, env, site.tsym, name);
1976 } else if (name == names._class) {
1977 // In this case, we have already made sure in
1978 // visitSelect that qualifier expression is a type.
1979 Type t = syms.classType;
1980 List<Type> typeargs = allowGenerics
1981 ? List.of(types.erasure(site))
1982 : List.<Type>nil();
1983 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
1984 return new VarSymbol(
1985 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
1986 } else {
1987 // We are seeing a plain identifier as selector.
1988 Symbol sym = rs.findIdentInType(env, site, name, pkind);
1989 if ((pkind & ERRONEOUS) == 0)
1990 sym = rs.access(sym, pos, site, name, true);
1991 return sym;
1992 }
1993 case WILDCARD:
1994 throw new AssertionError(tree);
1995 case TYPEVAR:
1996 // Normally, site.getUpperBound() shouldn't be null.
1997 // It should only happen during memberEnter/attribBase
1998 // when determining the super type which *must* be
1999 // done before attributing the type variables. In
2000 // other words, we are seeing this illegal program:
2001 // class B<T> extends A<T.foo> {}
2002 Symbol sym = (site.getUpperBound() != null)
2003 ? selectSym(tree, capture(site.getUpperBound()), env, pt, pkind)
2004 : null;
2005 if (sym == null || isType(sym)) {
2006 log.error(pos, "type.var.cant.be.deref");
2007 return syms.errSymbol;
2008 } else {
2009 return sym;
2010 }
2011 case ERROR:
2012 // preserve identifier names through errors
2013 return new ErrorType(name, site.tsym).tsym;
2014 default:
2015 // The qualifier expression is of a primitive type -- only
2016 // .class is allowed for these.
2017 if (name == names._class) {
2018 // In this case, we have already made sure in Select that
2019 // qualifier expression is a type.
2020 Type t = syms.classType;
2021 Type arg = types.boxedClass(site).type;
2022 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2023 return new VarSymbol(
2024 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2025 } else {
2026 log.error(pos, "cant.deref", site);
2027 return syms.errSymbol;
2028 }
2029 }
2030 }
2032 /** Determine type of identifier or select expression and check that
2033 * (1) the referenced symbol is not deprecated
2034 * (2) the symbol's type is safe (@see checkSafe)
2035 * (3) if symbol is a variable, check that its type and kind are
2036 * compatible with the prototype and protokind.
2037 * (4) if symbol is an instance field of a raw type,
2038 * which is being assigned to, issue an unchecked warning if its
2039 * type changes under erasure.
2040 * (5) if symbol is an instance method of a raw type, issue an
2041 * unchecked warning if its argument types change under erasure.
2042 * If checks succeed:
2043 * If symbol is a constant, return its constant type
2044 * else if symbol is a method, return its result type
2045 * otherwise return its type.
2046 * Otherwise return errType.
2047 *
2048 * @param tree The syntax tree representing the identifier
2049 * @param site If this is a select, the type of the selected
2050 * expression, otherwise the type of the current class.
2051 * @param sym The symbol representing the identifier.
2052 * @param env The current environment.
2053 * @param pkind The set of expected kinds.
2054 * @param pt The expected type.
2055 */
2056 Type checkId(JCTree tree,
2057 Type site,
2058 Symbol sym,
2059 Env<AttrContext> env,
2060 int pkind,
2061 Type pt,
2062 boolean useVarargs) {
2063 if (pt.isErroneous()) return syms.errType;
2064 Type owntype; // The computed type of this identifier occurrence.
2065 switch (sym.kind) {
2066 case TYP:
2067 // For types, the computed type equals the symbol's type,
2068 // except for two situations:
2069 owntype = sym.type;
2070 if (owntype.tag == CLASS) {
2071 Type ownOuter = owntype.getEnclosingType();
2073 // (a) If the symbol's type is parameterized, erase it
2074 // because no type parameters were given.
2075 // We recover generic outer type later in visitTypeApply.
2076 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2077 owntype = types.erasure(owntype);
2078 }
2080 // (b) If the symbol's type is an inner class, then
2081 // we have to interpret its outer type as a superclass
2082 // of the site type. Example:
2083 //
2084 // class Tree<A> { class Visitor { ... } }
2085 // class PointTree extends Tree<Point> { ... }
2086 // ...PointTree.Visitor...
2087 //
2088 // Then the type of the last expression above is
2089 // Tree<Point>.Visitor.
2090 else if (ownOuter.tag == CLASS && site != ownOuter) {
2091 Type normOuter = site;
2092 if (normOuter.tag == CLASS)
2093 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2094 if (normOuter == null) // perhaps from an import
2095 normOuter = types.erasure(ownOuter);
2096 if (normOuter != ownOuter)
2097 owntype = new ClassType(
2098 normOuter, List.<Type>nil(), owntype.tsym);
2099 }
2100 }
2101 break;
2102 case VAR:
2103 VarSymbol v = (VarSymbol)sym;
2104 // Test (4): if symbol is an instance field of a raw type,
2105 // which is being assigned to, issue an unchecked warning if
2106 // its type changes under erasure.
2107 if (allowGenerics &&
2108 pkind == VAR &&
2109 v.owner.kind == TYP &&
2110 (v.flags() & STATIC) == 0 &&
2111 (site.tag == CLASS || site.tag == TYPEVAR)) {
2112 Type s = types.asOuterSuper(site, v.owner);
2113 if (s != null &&
2114 s.isRaw() &&
2115 !types.isSameType(v.type, v.erasure(types))) {
2116 chk.warnUnchecked(tree.pos(),
2117 "unchecked.assign.to.var",
2118 v, s);
2119 }
2120 }
2121 // The computed type of a variable is the type of the
2122 // variable symbol, taken as a member of the site type.
2123 owntype = (sym.owner.kind == TYP &&
2124 sym.name != names._this && sym.name != names._super)
2125 ? types.memberType(site, sym)
2126 : sym.type;
2128 if (env.info.tvars.nonEmpty()) {
2129 Type owntype1 = new ForAll(env.info.tvars, owntype);
2130 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2131 if (!owntype.contains(l.head)) {
2132 log.error(tree.pos(), "undetermined.type", owntype1);
2133 owntype1 = syms.errType;
2134 }
2135 owntype = owntype1;
2136 }
2138 // If the variable is a constant, record constant value in
2139 // computed type.
2140 if (v.getConstValue() != null && isStaticReference(tree))
2141 owntype = owntype.constType(v.getConstValue());
2143 if (pkind == VAL) {
2144 owntype = capture(owntype); // capture "names as expressions"
2145 }
2146 break;
2147 case MTH: {
2148 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2149 owntype = checkMethod(site, sym, env, app.args,
2150 pt.getParameterTypes(), pt.getTypeArguments(),
2151 env.info.varArgs);
2152 break;
2153 }
2154 case PCK: case ERR:
2155 owntype = sym.type;
2156 break;
2157 default:
2158 throw new AssertionError("unexpected kind: " + sym.kind +
2159 " in tree " + tree);
2160 }
2162 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2163 // (for constructors, the error was given when the constructor was
2164 // resolved)
2165 if (sym.name != names.init &&
2166 (sym.flags() & DEPRECATED) != 0 &&
2167 (env.info.scope.owner.flags() & DEPRECATED) == 0 &&
2168 sym.outermostClass() != env.info.scope.owner.outermostClass())
2169 chk.warnDeprecated(tree.pos(), sym);
2171 if ((sym.flags() & PROPRIETARY) != 0)
2172 log.strictWarning(tree.pos(), "sun.proprietary", sym);
2174 // Test (3): if symbol is a variable, check that its type and
2175 // kind are compatible with the prototype and protokind.
2176 return check(tree, owntype, sym.kind, pkind, pt);
2177 }
2179 /** Check that variable is initialized and evaluate the variable's
2180 * initializer, if not yet done. Also check that variable is not
2181 * referenced before it is defined.
2182 * @param tree The tree making up the variable reference.
2183 * @param env The current environment.
2184 * @param v The variable's symbol.
2185 */
2186 private void checkInit(JCTree tree,
2187 Env<AttrContext> env,
2188 VarSymbol v,
2189 boolean onlyWarning) {
2190 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2191 // tree.pos + " " + v.pos + " " +
2192 // Resolve.isStatic(env));//DEBUG
2194 // A forward reference is diagnosed if the declaration position
2195 // of the variable is greater than the current tree position
2196 // and the tree and variable definition occur in the same class
2197 // definition. Note that writes don't count as references.
2198 // This check applies only to class and instance
2199 // variables. Local variables follow different scope rules,
2200 // and are subject to definite assignment checking.
2201 if (v.pos > tree.pos &&
2202 v.owner.kind == TYP &&
2203 canOwnInitializer(env.info.scope.owner) &&
2204 v.owner == env.info.scope.owner.enclClass() &&
2205 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2206 (env.tree.getTag() != JCTree.ASSIGN ||
2207 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2209 if (!onlyWarning || isNonStaticEnumField(v)) {
2210 log.error(tree.pos(), "illegal.forward.ref");
2211 } else if (useBeforeDeclarationWarning) {
2212 log.warning(tree.pos(), "forward.ref", v);
2213 }
2214 }
2216 v.getConstValue(); // ensure initializer is evaluated
2218 checkEnumInitializer(tree, env, v);
2219 }
2221 /**
2222 * Check for illegal references to static members of enum. In
2223 * an enum type, constructors and initializers may not
2224 * reference its static members unless they are constant.
2225 *
2226 * @param tree The tree making up the variable reference.
2227 * @param env The current environment.
2228 * @param v The variable's symbol.
2229 * @see JLS 3rd Ed. (8.9 Enums)
2230 */
2231 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2232 // JLS 3rd Ed.:
2233 //
2234 // "It is a compile-time error to reference a static field
2235 // of an enum type that is not a compile-time constant
2236 // (15.28) from constructors, instance initializer blocks,
2237 // or instance variable initializer expressions of that
2238 // type. It is a compile-time error for the constructors,
2239 // instance initializer blocks, or instance variable
2240 // initializer expressions of an enum constant e to refer
2241 // to itself or to an enum constant of the same type that
2242 // is declared to the right of e."
2243 if (isNonStaticEnumField(v)) {
2244 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2246 if (enclClass == null || enclClass.owner == null)
2247 return;
2249 // See if the enclosing class is the enum (or a
2250 // subclass thereof) declaring v. If not, this
2251 // reference is OK.
2252 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2253 return;
2255 // If the reference isn't from an initializer, then
2256 // the reference is OK.
2257 if (!Resolve.isInitializer(env))
2258 return;
2260 log.error(tree.pos(), "illegal.enum.static.ref");
2261 }
2262 }
2264 private boolean isNonStaticEnumField(VarSymbol v) {
2265 return Flags.isEnum(v.owner) && Flags.isStatic(v) && !Flags.isConstant(v);
2266 }
2268 /** Can the given symbol be the owner of code which forms part
2269 * if class initialization? This is the case if the symbol is
2270 * a type or field, or if the symbol is the synthetic method.
2271 * owning a block.
2272 */
2273 private boolean canOwnInitializer(Symbol sym) {
2274 return
2275 (sym.kind & (VAR | TYP)) != 0 ||
2276 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2277 }
2279 Warner noteWarner = new Warner();
2281 /**
2282 * Check that method arguments conform to its instantation.
2283 **/
2284 public Type checkMethod(Type site,
2285 Symbol sym,
2286 Env<AttrContext> env,
2287 final List<JCExpression> argtrees,
2288 List<Type> argtypes,
2289 List<Type> typeargtypes,
2290 boolean useVarargs) {
2291 // Test (5): if symbol is an instance method of a raw type, issue
2292 // an unchecked warning if its argument types change under erasure.
2293 if (allowGenerics &&
2294 (sym.flags() & STATIC) == 0 &&
2295 (site.tag == CLASS || site.tag == TYPEVAR)) {
2296 Type s = types.asOuterSuper(site, sym.owner);
2297 if (s != null && s.isRaw() &&
2298 !types.isSameTypes(sym.type.getParameterTypes(),
2299 sym.erasure(types).getParameterTypes())) {
2300 chk.warnUnchecked(env.tree.pos(),
2301 "unchecked.call.mbr.of.raw.type",
2302 sym, s);
2303 }
2304 }
2306 // Compute the identifier's instantiated type.
2307 // For methods, we need to compute the instance type by
2308 // Resolve.instantiate from the symbol's type as well as
2309 // any type arguments and value arguments.
2310 noteWarner.warned = false;
2311 Type owntype = rs.instantiate(env,
2312 site,
2313 sym,
2314 argtypes,
2315 typeargtypes,
2316 true,
2317 useVarargs,
2318 noteWarner);
2319 boolean warned = noteWarner.warned;
2321 // If this fails, something went wrong; we should not have
2322 // found the identifier in the first place.
2323 if (owntype == null) {
2324 if (!pt.isErroneous())
2325 log.error(env.tree.pos(),
2326 "internal.error.cant.instantiate",
2327 sym, site,
2328 Type.toString(pt.getParameterTypes()));
2329 owntype = syms.errType;
2330 } else {
2331 // System.out.println("call : " + env.tree);
2332 // System.out.println("method : " + owntype);
2333 // System.out.println("actuals: " + argtypes);
2334 List<Type> formals = owntype.getParameterTypes();
2335 Type last = useVarargs ? formals.last() : null;
2336 if (sym.name==names.init &&
2337 sym.owner == syms.enumSym)
2338 formals = formals.tail.tail;
2339 List<JCExpression> args = argtrees;
2340 while (formals.head != last) {
2341 JCTree arg = args.head;
2342 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2343 assertConvertible(arg, arg.type, formals.head, warn);
2344 warned |= warn.warned;
2345 args = args.tail;
2346 formals = formals.tail;
2347 }
2348 if (useVarargs) {
2349 Type varArg = types.elemtype(last);
2350 while (args.tail != null) {
2351 JCTree arg = args.head;
2352 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2353 assertConvertible(arg, arg.type, varArg, warn);
2354 warned |= warn.warned;
2355 args = args.tail;
2356 }
2357 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2358 // non-varargs call to varargs method
2359 Type varParam = owntype.getParameterTypes().last();
2360 Type lastArg = argtypes.last();
2361 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2362 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2363 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2364 types.elemtype(varParam),
2365 varParam);
2366 }
2368 if (warned && sym.type.tag == FORALL) {
2369 String typeargs = "";
2370 if (typeargtypes != null && typeargtypes.nonEmpty()) {
2371 typeargs = "<" + Type.toString(typeargtypes) + ">";
2372 }
2373 chk.warnUnchecked(env.tree.pos(),
2374 "unchecked.meth.invocation.applied",
2375 sym,
2376 sym.location(),
2377 typeargs,
2378 Type.toString(argtypes));
2379 owntype = new MethodType(owntype.getParameterTypes(),
2380 types.erasure(owntype.getReturnType()),
2381 owntype.getThrownTypes(),
2382 syms.methodClass);
2383 }
2384 if (useVarargs) {
2385 JCTree tree = env.tree;
2386 Type argtype = owntype.getParameterTypes().last();
2387 if (!types.isReifiable(argtype))
2388 chk.warnUnchecked(env.tree.pos(),
2389 "unchecked.generic.array.creation",
2390 argtype);
2391 Type elemtype = types.elemtype(argtype);
2392 switch (tree.getTag()) {
2393 case JCTree.APPLY:
2394 ((JCMethodInvocation) tree).varargsElement = elemtype;
2395 break;
2396 case JCTree.NEWCLASS:
2397 ((JCNewClass) tree).varargsElement = elemtype;
2398 break;
2399 default:
2400 throw new AssertionError(""+tree);
2401 }
2402 }
2403 }
2404 return owntype;
2405 }
2407 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2408 if (types.isConvertible(actual, formal, warn))
2409 return;
2411 if (formal.isCompound()
2412 && types.isSubtype(actual, types.supertype(formal))
2413 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2414 return;
2416 if (false) {
2417 // TODO: make assertConvertible work
2418 chk.typeError(tree.pos(), JCDiagnostic.fragment("incompatible.types"), actual, formal);
2419 throw new AssertionError("Tree: " + tree
2420 + " actual:" + actual
2421 + " formal: " + formal);
2422 }
2423 }
2425 public void visitLiteral(JCLiteral tree) {
2426 result = check(
2427 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2428 }
2429 //where
2430 /** Return the type of a literal with given type tag.
2431 */
2432 Type litType(int tag) {
2433 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2434 }
2436 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2437 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2438 }
2440 public void visitTypeArray(JCArrayTypeTree tree) {
2441 Type etype = attribType(tree.elemtype, env);
2442 Type type = new ArrayType(etype, syms.arrayClass);
2443 result = check(tree, type, TYP, pkind, pt);
2444 }
2446 /** Visitor method for parameterized types.
2447 * Bound checking is left until later, since types are attributed
2448 * before supertype structure is completely known
2449 */
2450 public void visitTypeApply(JCTypeApply tree) {
2451 Type owntype = syms.errType;
2453 // Attribute functor part of application and make sure it's a class.
2454 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2456 // Attribute type parameters
2457 List<Type> actuals = attribTypes(tree.arguments, env);
2459 if (clazztype.tag == CLASS) {
2460 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2462 if (actuals.length() == formals.length()) {
2463 List<Type> a = actuals;
2464 List<Type> f = formals;
2465 while (a.nonEmpty()) {
2466 a.head = a.head.withTypeVar(f.head);
2467 a = a.tail;
2468 f = f.tail;
2469 }
2470 // Compute the proper generic outer
2471 Type clazzOuter = clazztype.getEnclosingType();
2472 if (clazzOuter.tag == CLASS) {
2473 Type site;
2474 if (tree.clazz.getTag() == JCTree.IDENT) {
2475 site = env.enclClass.sym.type;
2476 } else if (tree.clazz.getTag() == JCTree.SELECT) {
2477 site = ((JCFieldAccess) tree.clazz).selected.type;
2478 } else throw new AssertionError(""+tree);
2479 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2480 if (site.tag == CLASS)
2481 site = types.asOuterSuper(site, clazzOuter.tsym);
2482 if (site == null)
2483 site = types.erasure(clazzOuter);
2484 clazzOuter = site;
2485 }
2486 }
2487 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2488 } else {
2489 if (formals.length() != 0) {
2490 log.error(tree.pos(), "wrong.number.type.args",
2491 Integer.toString(formals.length()));
2492 } else {
2493 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2494 }
2495 owntype = syms.errType;
2496 }
2497 }
2498 result = check(tree, owntype, TYP, pkind, pt);
2499 }
2501 public void visitTypeParameter(JCTypeParameter tree) {
2502 TypeVar a = (TypeVar)tree.type;
2503 Set<Type> boundSet = new HashSet<Type>();
2504 if (a.bound.isErroneous())
2505 return;
2506 List<Type> bs = types.getBounds(a);
2507 if (tree.bounds.nonEmpty()) {
2508 // accept class or interface or typevar as first bound.
2509 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2510 boundSet.add(types.erasure(b));
2511 if (b.tag == TYPEVAR) {
2512 // if first bound was a typevar, do not accept further bounds.
2513 if (tree.bounds.tail.nonEmpty()) {
2514 log.error(tree.bounds.tail.head.pos(),
2515 "type.var.may.not.be.followed.by.other.bounds");
2516 tree.bounds = List.of(tree.bounds.head);
2517 a.bound = bs.head;
2518 }
2519 } else {
2520 // if first bound was a class or interface, accept only interfaces
2521 // as further bounds.
2522 for (JCExpression bound : tree.bounds.tail) {
2523 bs = bs.tail;
2524 Type i = checkBase(bs.head, bound, env, false, true, false);
2525 if (i.tag == CLASS)
2526 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
2527 }
2528 }
2529 }
2530 bs = types.getBounds(a);
2532 // in case of multiple bounds ...
2533 if (bs.length() > 1) {
2534 // ... the variable's bound is a class type flagged COMPOUND
2535 // (see comment for TypeVar.bound).
2536 // In this case, generate a class tree that represents the
2537 // bound class, ...
2538 JCTree extending;
2539 List<JCExpression> implementing;
2540 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
2541 extending = tree.bounds.head;
2542 implementing = tree.bounds.tail;
2543 } else {
2544 extending = null;
2545 implementing = tree.bounds;
2546 }
2547 JCClassDecl cd = make.at(tree.pos).ClassDef(
2548 make.Modifiers(PUBLIC | ABSTRACT),
2549 tree.name, List.<JCTypeParameter>nil(),
2550 extending, implementing, List.<JCTree>nil());
2552 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
2553 assert (c.flags() & COMPOUND) != 0;
2554 cd.sym = c;
2555 c.sourcefile = env.toplevel.sourcefile;
2557 // ... and attribute the bound class
2558 c.flags_field |= UNATTRIBUTED;
2559 Env<AttrContext> cenv = enter.classEnv(cd, env);
2560 enter.typeEnvs.put(c, cenv);
2561 }
2562 }
2565 public void visitWildcard(JCWildcard tree) {
2566 //- System.err.println("visitWildcard("+tree+");");//DEBUG
2567 Type type = (tree.kind.kind == BoundKind.UNBOUND)
2568 ? syms.objectType
2569 : attribType(tree.inner, env);
2570 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
2571 tree.kind.kind,
2572 syms.boundClass),
2573 TYP, pkind, pt);
2574 }
2576 public void visitAnnotation(JCAnnotation tree) {
2577 log.error(tree.pos(), "annotation.not.valid.for.type", pt);
2578 result = tree.type = syms.errType;
2579 }
2581 public void visitErroneous(JCErroneous tree) {
2582 if (tree.errs != null)
2583 for (JCTree err : tree.errs)
2584 attribTree(err, env, ERR, pt);
2585 result = tree.type = syms.errType;
2586 }
2588 /** Default visitor method for all other trees.
2589 */
2590 public void visitTree(JCTree tree) {
2591 throw new AssertionError();
2592 }
2594 /** Main method: attribute class definition associated with given class symbol.
2595 * reporting completion failures at the given position.
2596 * @param pos The source position at which completion errors are to be
2597 * reported.
2598 * @param c The class symbol whose definition will be attributed.
2599 */
2600 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
2601 try {
2602 annotate.flush();
2603 attribClass(c);
2604 } catch (CompletionFailure ex) {
2605 chk.completionError(pos, ex);
2606 }
2607 }
2609 /** Attribute class definition associated with given class symbol.
2610 * @param c The class symbol whose definition will be attributed.
2611 */
2612 void attribClass(ClassSymbol c) throws CompletionFailure {
2613 if (c.type.tag == ERROR) return;
2615 // Check for cycles in the inheritance graph, which can arise from
2616 // ill-formed class files.
2617 chk.checkNonCyclic(null, c.type);
2619 Type st = types.supertype(c.type);
2620 if ((c.flags_field & Flags.COMPOUND) == 0) {
2621 // First, attribute superclass.
2622 if (st.tag == CLASS)
2623 attribClass((ClassSymbol)st.tsym);
2625 // Next attribute owner, if it is a class.
2626 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
2627 attribClass((ClassSymbol)c.owner);
2628 }
2630 // The previous operations might have attributed the current class
2631 // if there was a cycle. So we test first whether the class is still
2632 // UNATTRIBUTED.
2633 if ((c.flags_field & UNATTRIBUTED) != 0) {
2634 c.flags_field &= ~UNATTRIBUTED;
2636 // Get environment current at the point of class definition.
2637 Env<AttrContext> env = enter.typeEnvs.get(c);
2639 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
2640 // because the annotations were not available at the time the env was created. Therefore,
2641 // we look up the environment chain for the first enclosing environment for which the
2642 // lint value is set. Typically, this is the parent env, but might be further if there
2643 // are any envs created as a result of TypeParameter nodes.
2644 Env<AttrContext> lintEnv = env;
2645 while (lintEnv.info.lint == null)
2646 lintEnv = lintEnv.next;
2648 // Having found the enclosing lint value, we can initialize the lint value for this class
2649 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
2651 Lint prevLint = chk.setLint(env.info.lint);
2652 JavaFileObject prev = log.useSource(c.sourcefile);
2654 try {
2655 // java.lang.Enum may not be subclassed by a non-enum
2656 if (st.tsym == syms.enumSym &&
2657 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
2658 log.error(env.tree.pos(), "enum.no.subclassing");
2660 // Enums may not be extended by source-level classes
2661 if (st.tsym != null &&
2662 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
2663 ((c.flags_field & Flags.ENUM) == 0) &&
2664 !target.compilerBootstrap(c)) {
2665 log.error(env.tree.pos(), "enum.types.not.extensible");
2666 }
2667 attribClassBody(env, c);
2669 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
2670 } finally {
2671 log.useSource(prev);
2672 chk.setLint(prevLint);
2673 }
2675 }
2676 }
2678 public void visitImport(JCImport tree) {
2679 // nothing to do
2680 }
2682 /** Finish the attribution of a class. */
2683 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
2684 JCClassDecl tree = (JCClassDecl)env.tree;
2685 assert c == tree.sym;
2687 // Validate annotations
2688 chk.validateAnnotations(tree.mods.annotations, c);
2690 // Validate type parameters, supertype and interfaces.
2691 attribBounds(tree.typarams, env);
2692 chk.validateTypeParams(tree.typarams);
2693 chk.validate(tree.extending);
2694 chk.validate(tree.implementing);
2696 // If this is a non-abstract class, check that it has no abstract
2697 // methods or unimplemented methods of an implemented interface.
2698 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
2699 if (!relax)
2700 chk.checkAllDefined(tree.pos(), c);
2701 }
2703 if ((c.flags() & ANNOTATION) != 0) {
2704 if (tree.implementing.nonEmpty())
2705 log.error(tree.implementing.head.pos(),
2706 "cant.extend.intf.annotation");
2707 if (tree.typarams.nonEmpty())
2708 log.error(tree.typarams.head.pos(),
2709 "intf.annotation.cant.have.type.params");
2710 } else {
2711 // Check that all extended classes and interfaces
2712 // are compatible (i.e. no two define methods with same arguments
2713 // yet different return types). (JLS 8.4.6.3)
2714 chk.checkCompatibleSupertypes(tree.pos(), c.type);
2715 }
2717 // Check that class does not import the same parameterized interface
2718 // with two different argument lists.
2719 chk.checkClassBounds(tree.pos(), c.type);
2721 tree.type = c.type;
2723 boolean assertsEnabled = false;
2724 assert assertsEnabled = true;
2725 if (assertsEnabled) {
2726 for (List<JCTypeParameter> l = tree.typarams;
2727 l.nonEmpty(); l = l.tail)
2728 assert env.info.scope.lookup(l.head.name).scope != null;
2729 }
2731 // Check that a generic class doesn't extend Throwable
2732 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
2733 log.error(tree.extending.pos(), "generic.throwable");
2735 // Check that all methods which implement some
2736 // method conform to the method they implement.
2737 chk.checkImplementations(tree);
2739 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2740 // Attribute declaration
2741 attribStat(l.head, env);
2742 // Check that declarations in inner classes are not static (JLS 8.1.2)
2743 // Make an exception for static constants.
2744 if (c.owner.kind != PCK &&
2745 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
2746 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
2747 Symbol sym = null;
2748 if (l.head.getTag() == JCTree.VARDEF) sym = ((JCVariableDecl) l.head).sym;
2749 if (sym == null ||
2750 sym.kind != VAR ||
2751 ((VarSymbol) sym).getConstValue() == null)
2752 log.error(l.head.pos(), "icls.cant.have.static.decl");
2753 }
2754 }
2756 // Check for cycles among non-initial constructors.
2757 chk.checkCyclicConstructors(tree);
2759 // Check for cycles among annotation elements.
2760 chk.checkNonCyclicElements(tree);
2762 // Check for proper use of serialVersionUID
2763 if (env.info.lint.isEnabled(Lint.LintCategory.SERIAL) &&
2764 isSerializable(c) &&
2765 (c.flags() & Flags.ENUM) == 0 &&
2766 (c.flags() & ABSTRACT) == 0) {
2767 checkSerialVersionUID(tree, c);
2768 }
2769 }
2770 // where
2771 /** check if a class is a subtype of Serializable, if that is available. */
2772 private boolean isSerializable(ClassSymbol c) {
2773 try {
2774 syms.serializableType.complete();
2775 }
2776 catch (CompletionFailure e) {
2777 return false;
2778 }
2779 return types.isSubtype(c.type, syms.serializableType);
2780 }
2782 /** Check that an appropriate serialVersionUID member is defined. */
2783 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
2785 // check for presence of serialVersionUID
2786 Scope.Entry e = c.members().lookup(names.serialVersionUID);
2787 while (e.scope != null && e.sym.kind != VAR) e = e.next();
2788 if (e.scope == null) {
2789 log.warning(tree.pos(), "missing.SVUID", c);
2790 return;
2791 }
2793 // check that it is static final
2794 VarSymbol svuid = (VarSymbol)e.sym;
2795 if ((svuid.flags() & (STATIC | FINAL)) !=
2796 (STATIC | FINAL))
2797 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
2799 // check that it is long
2800 else if (svuid.type.tag != TypeTags.LONG)
2801 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
2803 // check constant
2804 else if (svuid.getConstValue() == null)
2805 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
2806 }
2808 private Type capture(Type type) {
2809 return types.capture(type);
2810 }
2811 }