Thu, 05 Mar 2009 17:24:40 +0000
6804733: javac generates spourious diagnostics for ill-formed type-variable bounds
Summary: fixed algorithm for checking cycles in typevar declarations
Reviewed-by: jjg
1 /*
2 * Copyright 1999-2008 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 Names 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 JCDiagnostic.Factory diags;
83 final Annotate annotate;
85 public static Attr instance(Context context) {
86 Attr instance = context.get(attrKey);
87 if (instance == null)
88 instance = new Attr(context);
89 return instance;
90 }
92 protected Attr(Context context) {
93 context.put(attrKey, this);
95 names = Names.instance(context);
96 log = Log.instance(context);
97 syms = Symtab.instance(context);
98 rs = Resolve.instance(context);
99 chk = Check.instance(context);
100 memberEnter = MemberEnter.instance(context);
101 make = TreeMaker.instance(context);
102 enter = Enter.instance(context);
103 cfolder = ConstFold.instance(context);
104 target = Target.instance(context);
105 types = Types.instance(context);
106 diags = JCDiagnostic.Factory.instance(context);
107 annotate = Annotate.instance(context);
109 Options options = Options.instance(context);
111 Source source = Source.instance(context);
112 allowGenerics = source.allowGenerics();
113 allowVarargs = source.allowVarargs();
114 allowEnums = source.allowEnums();
115 allowBoxing = source.allowBoxing();
116 allowCovariantReturns = source.allowCovariantReturns();
117 allowAnonOuterThis = source.allowAnonOuterThis();
118 relax = (options.get("-retrofit") != null ||
119 options.get("-relax") != null);
120 useBeforeDeclarationWarning = options.get("useBeforeDeclarationWarning") != null;
121 }
123 /** Switch: relax some constraints for retrofit mode.
124 */
125 boolean relax;
127 /** Switch: support generics?
128 */
129 boolean allowGenerics;
131 /** Switch: allow variable-arity methods.
132 */
133 boolean allowVarargs;
135 /** Switch: support enums?
136 */
137 boolean allowEnums;
139 /** Switch: support boxing and unboxing?
140 */
141 boolean allowBoxing;
143 /** Switch: support covariant result types?
144 */
145 boolean allowCovariantReturns;
147 /** Switch: allow references to surrounding object from anonymous
148 * objects during constructor call?
149 */
150 boolean allowAnonOuterThis;
152 /**
153 * Switch: warn about use of variable before declaration?
154 * RFE: 6425594
155 */
156 boolean useBeforeDeclarationWarning;
158 /** Check kind and type of given tree against protokind and prototype.
159 * If check succeeds, store type in tree and return it.
160 * If check fails, store errType in tree and return it.
161 * No checks are performed if the prototype is a method type.
162 * It is not necessary in this case since we know that kind and type
163 * are correct.
164 *
165 * @param tree The tree whose kind and type is checked
166 * @param owntype The computed type of the tree
167 * @param ownkind The computed kind of the tree
168 * @param pkind The expected kind (or: protokind) of the tree
169 * @param pt The expected type (or: prototype) of the tree
170 */
171 Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
172 if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
173 if ((ownkind & ~pkind) == 0) {
174 owntype = chk.checkType(tree.pos(), owntype, pt);
175 } else {
176 log.error(tree.pos(), "unexpected.type",
177 kindNames(pkind),
178 kindName(ownkind));
179 owntype = types.createErrorType(owntype);
180 }
181 }
182 tree.type = owntype;
183 return owntype;
184 }
186 /** Is given blank final variable assignable, i.e. in a scope where it
187 * may be assigned to even though it is final?
188 * @param v The blank final variable.
189 * @param env The current environment.
190 */
191 boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
192 Symbol owner = env.info.scope.owner;
193 // owner refers to the innermost variable, method or
194 // initializer block declaration at this point.
195 return
196 v.owner == owner
197 ||
198 ((owner.name == names.init || // i.e. we are in a constructor
199 owner.kind == VAR || // i.e. we are in a variable initializer
200 (owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
201 &&
202 v.owner == owner.owner
203 &&
204 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
205 }
207 /** Check that variable can be assigned to.
208 * @param pos The current source code position.
209 * @param v The assigned varaible
210 * @param base If the variable is referred to in a Select, the part
211 * to the left of the `.', null otherwise.
212 * @param env The current environment.
213 */
214 void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
215 if ((v.flags() & FINAL) != 0 &&
216 ((v.flags() & HASINIT) != 0
217 ||
218 !((base == null ||
219 (base.getTag() == JCTree.IDENT && TreeInfo.name(base) == names._this)) &&
220 isAssignableAsBlankFinal(v, env)))) {
221 log.error(pos, "cant.assign.val.to.final.var", v);
222 }
223 }
225 /** Does tree represent a static reference to an identifier?
226 * It is assumed that tree is either a SELECT or an IDENT.
227 * We have to weed out selects from non-type names here.
228 * @param tree The candidate tree.
229 */
230 boolean isStaticReference(JCTree tree) {
231 if (tree.getTag() == JCTree.SELECT) {
232 Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
233 if (lsym == null || lsym.kind != TYP) {
234 return false;
235 }
236 }
237 return true;
238 }
240 /** Is this symbol a type?
241 */
242 static boolean isType(Symbol sym) {
243 return sym != null && sym.kind == TYP;
244 }
246 /** The current `this' symbol.
247 * @param env The current environment.
248 */
249 Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
250 return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
251 }
253 /** Attribute a parsed identifier.
254 * @param tree Parsed identifier name
255 * @param topLevel The toplevel to use
256 */
257 public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
258 Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
259 localEnv.enclClass = make.ClassDef(make.Modifiers(0),
260 syms.errSymbol.name,
261 null, null, null, null);
262 localEnv.enclClass.sym = syms.errSymbol;
263 return tree.accept(identAttributer, localEnv);
264 }
265 // where
266 private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
267 private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
268 @Override
269 public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
270 Symbol site = visit(node.getExpression(), env);
271 if (site.kind == ERR)
272 return site;
273 Name name = (Name)node.getIdentifier();
274 if (site.kind == PCK) {
275 env.toplevel.packge = (PackageSymbol)site;
276 return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
277 } else {
278 env.enclClass.sym = (ClassSymbol)site;
279 return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
280 }
281 }
283 @Override
284 public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
285 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
286 }
287 }
289 public Type coerce(Type etype, Type ttype) {
290 return cfolder.coerce(etype, ttype);
291 }
293 public Type attribType(JCTree node, TypeSymbol sym) {
294 Env<AttrContext> env = enter.typeEnvs.get(sym);
295 Env<AttrContext> localEnv = env.dup(node, env.info.dup());
296 return attribTree(node, localEnv, Kinds.TYP, Type.noType);
297 }
299 public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
300 breakTree = tree;
301 JavaFileObject prev = log.useSource(null);
302 try {
303 attribExpr(expr, env);
304 } catch (BreakAttr b) {
305 return b.env;
306 } finally {
307 breakTree = null;
308 log.useSource(prev);
309 }
310 return env;
311 }
313 public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
314 breakTree = tree;
315 JavaFileObject prev = log.useSource(null);
316 try {
317 attribStat(stmt, env);
318 } catch (BreakAttr b) {
319 return b.env;
320 } finally {
321 breakTree = null;
322 log.useSource(prev);
323 }
324 return env;
325 }
327 private JCTree breakTree = null;
329 private static class BreakAttr extends RuntimeException {
330 static final long serialVersionUID = -6924771130405446405L;
331 private Env<AttrContext> env;
332 private BreakAttr(Env<AttrContext> env) {
333 this.env = env;
334 }
335 }
338 /* ************************************************************************
339 * Visitor methods
340 *************************************************************************/
342 /** Visitor argument: the current environment.
343 */
344 Env<AttrContext> env;
346 /** Visitor argument: the currently expected proto-kind.
347 */
348 int pkind;
350 /** Visitor argument: the currently expected proto-type.
351 */
352 Type pt;
354 /** Visitor result: the computed type.
355 */
356 Type result;
358 /** Visitor method: attribute a tree, catching any completion failure
359 * exceptions. Return the tree's type.
360 *
361 * @param tree The tree to be visited.
362 * @param env The environment visitor argument.
363 * @param pkind The protokind visitor argument.
364 * @param pt The prototype visitor argument.
365 */
366 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) {
367 Env<AttrContext> prevEnv = this.env;
368 int prevPkind = this.pkind;
369 Type prevPt = this.pt;
370 try {
371 this.env = env;
372 this.pkind = pkind;
373 this.pt = pt;
374 tree.accept(this);
375 if (tree == breakTree)
376 throw new BreakAttr(env);
377 return result;
378 } catch (CompletionFailure ex) {
379 tree.type = syms.errType;
380 return chk.completionError(tree.pos(), ex);
381 } finally {
382 this.env = prevEnv;
383 this.pkind = prevPkind;
384 this.pt = prevPt;
385 }
386 }
388 /** Derived visitor method: attribute an expression tree.
389 */
390 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
391 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
392 }
394 /** Derived visitor method: attribute an expression tree with
395 * no constraints on the computed type.
396 */
397 Type attribExpr(JCTree tree, Env<AttrContext> env) {
398 return attribTree(tree, env, VAL, Type.noType);
399 }
401 /** Derived visitor method: attribute a type tree.
402 */
403 Type attribType(JCTree tree, Env<AttrContext> env) {
404 Type result = attribTree(tree, env, TYP, Type.noType);
405 return result;
406 }
408 /** Derived visitor method: attribute a statement or definition tree.
409 */
410 public Type attribStat(JCTree tree, Env<AttrContext> env) {
411 return attribTree(tree, env, NIL, Type.noType);
412 }
414 /** Attribute a list of expressions, returning a list of types.
415 */
416 List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
417 ListBuffer<Type> ts = new ListBuffer<Type>();
418 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
419 ts.append(attribExpr(l.head, env, pt));
420 return ts.toList();
421 }
423 /** Attribute a list of statements, returning nothing.
424 */
425 <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
426 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
427 attribStat(l.head, env);
428 }
430 /** Attribute the arguments in a method call, returning a list of types.
431 */
432 List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
433 ListBuffer<Type> argtypes = new ListBuffer<Type>();
434 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
435 argtypes.append(chk.checkNonVoid(
436 l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly))));
437 return argtypes.toList();
438 }
440 /** Attribute a type argument list, returning a list of types.
441 */
442 List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
443 ListBuffer<Type> argtypes = new ListBuffer<Type>();
444 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
445 argtypes.append(chk.checkRefType(l.head.pos(), attribType(l.head, env)));
446 return argtypes.toList();
447 }
450 /**
451 * Attribute type variables (of generic classes or methods).
452 * Compound types are attributed later in attribBounds.
453 * @param typarams the type variables to enter
454 * @param env the current environment
455 */
456 void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
457 for (JCTypeParameter tvar : typarams) {
458 TypeVar a = (TypeVar)tvar.type;
459 a.tsym.flags_field |= UNATTRIBUTED;
460 a.bound = Type.noType;
461 if (!tvar.bounds.isEmpty()) {
462 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
463 for (JCExpression bound : tvar.bounds.tail)
464 bounds = bounds.prepend(attribType(bound, env));
465 types.setBounds(a, bounds.reverse());
466 } else {
467 // if no bounds are given, assume a single bound of
468 // java.lang.Object.
469 types.setBounds(a, List.of(syms.objectType));
470 }
471 a.tsym.flags_field &= ~UNATTRIBUTED;
472 }
473 for (JCTypeParameter tvar : typarams)
474 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
475 attribStats(typarams, env);
476 }
478 void attribBounds(List<JCTypeParameter> typarams) {
479 for (JCTypeParameter typaram : typarams) {
480 Type bound = typaram.type.getUpperBound();
481 if (bound != null && bound.tsym instanceof ClassSymbol) {
482 ClassSymbol c = (ClassSymbol)bound.tsym;
483 if ((c.flags_field & COMPOUND) != 0) {
484 assert (c.flags_field & UNATTRIBUTED) != 0 : c;
485 attribClass(typaram.pos(), c);
486 }
487 }
488 }
489 }
491 /**
492 * Attribute the type references in a list of annotations.
493 */
494 void attribAnnotationTypes(List<JCAnnotation> annotations,
495 Env<AttrContext> env) {
496 for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
497 JCAnnotation a = al.head;
498 attribType(a.annotationType, env);
499 }
500 }
502 /** Attribute type reference in an `extends' or `implements' clause.
503 *
504 * @param tree The tree making up the type reference.
505 * @param env The environment current at the reference.
506 * @param classExpected true if only a class is expected here.
507 * @param interfaceExpected true if only an interface is expected here.
508 */
509 Type attribBase(JCTree tree,
510 Env<AttrContext> env,
511 boolean classExpected,
512 boolean interfaceExpected,
513 boolean checkExtensible) {
514 Type t = attribType(tree, env);
515 return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
516 }
517 Type checkBase(Type t,
518 JCTree tree,
519 Env<AttrContext> env,
520 boolean classExpected,
521 boolean interfaceExpected,
522 boolean checkExtensible) {
523 if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
524 // check that type variable is already visible
525 if (t.getUpperBound() == null) {
526 log.error(tree.pos(), "illegal.forward.ref");
527 return types.createErrorType(t);
528 }
529 } else {
530 t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
531 }
532 if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
533 log.error(tree.pos(), "intf.expected.here");
534 // return errType is necessary since otherwise there might
535 // be undetected cycles which cause attribution to loop
536 return types.createErrorType(t);
537 } else if (checkExtensible &&
538 classExpected &&
539 (t.tsym.flags() & INTERFACE) != 0) {
540 log.error(tree.pos(), "no.intf.expected.here");
541 return types.createErrorType(t);
542 }
543 if (checkExtensible &&
544 ((t.tsym.flags() & FINAL) != 0)) {
545 log.error(tree.pos(),
546 "cant.inherit.from.final", t.tsym);
547 }
548 chk.checkNonCyclic(tree.pos(), t);
549 return t;
550 }
552 public void visitClassDef(JCClassDecl tree) {
553 // Local classes have not been entered yet, so we need to do it now:
554 if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
555 enter.classEnter(tree, env);
557 ClassSymbol c = tree.sym;
558 if (c == null) {
559 // exit in case something drastic went wrong during enter.
560 result = null;
561 } else {
562 // make sure class has been completed:
563 c.complete();
565 // If this class appears as an anonymous class
566 // in a superclass constructor call where
567 // no explicit outer instance is given,
568 // disable implicit outer instance from being passed.
569 // (This would be an illegal access to "this before super").
570 if (env.info.isSelfCall &&
571 env.tree.getTag() == JCTree.NEWCLASS &&
572 ((JCNewClass) env.tree).encl == null)
573 {
574 c.flags_field |= NOOUTERTHIS;
575 }
576 attribClass(tree.pos(), c);
577 result = tree.type = c.type;
578 }
579 }
581 public void visitMethodDef(JCMethodDecl tree) {
582 MethodSymbol m = tree.sym;
584 Lint lint = env.info.lint.augment(m.attributes_field, m.flags());
585 Lint prevLint = chk.setLint(lint);
586 try {
587 chk.checkDeprecatedAnnotation(tree.pos(), m);
589 attribBounds(tree.typarams);
591 // If we override any other methods, check that we do so properly.
592 // JLS ???
593 chk.checkOverride(tree, m);
595 // Create a new environment with local scope
596 // for attributing the method.
597 Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
599 localEnv.info.lint = lint;
601 // Enter all type parameters into the local method scope.
602 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
603 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
605 ClassSymbol owner = env.enclClass.sym;
606 if ((owner.flags() & ANNOTATION) != 0 &&
607 tree.params.nonEmpty())
608 log.error(tree.params.head.pos(),
609 "intf.annotation.members.cant.have.params");
611 // Attribute all value parameters.
612 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
613 attribStat(l.head, localEnv);
614 }
616 // Check that type parameters are well-formed.
617 chk.validate(tree.typarams, localEnv);
618 if ((owner.flags() & ANNOTATION) != 0 &&
619 tree.typarams.nonEmpty())
620 log.error(tree.typarams.head.pos(),
621 "intf.annotation.members.cant.have.type.params");
623 // Check that result type is well-formed.
624 chk.validate(tree.restype, localEnv);
625 if ((owner.flags() & ANNOTATION) != 0)
626 chk.validateAnnotationType(tree.restype);
628 if ((owner.flags() & ANNOTATION) != 0)
629 chk.validateAnnotationMethod(tree.pos(), m);
631 // Check that all exceptions mentioned in the throws clause extend
632 // java.lang.Throwable.
633 if ((owner.flags() & ANNOTATION) != 0 && tree.thrown.nonEmpty())
634 log.error(tree.thrown.head.pos(),
635 "throws.not.allowed.in.intf.annotation");
636 for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
637 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
639 if (tree.body == null) {
640 // Empty bodies are only allowed for
641 // abstract, native, or interface methods, or for methods
642 // in a retrofit signature class.
643 if ((owner.flags() & INTERFACE) == 0 &&
644 (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 &&
645 !relax)
646 log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
647 if (tree.defaultValue != null) {
648 if ((owner.flags() & ANNOTATION) == 0)
649 log.error(tree.pos(),
650 "default.allowed.in.intf.annotation.member");
651 }
652 } else if ((owner.flags() & INTERFACE) != 0) {
653 log.error(tree.body.pos(), "intf.meth.cant.have.body");
654 } else if ((tree.mods.flags & ABSTRACT) != 0) {
655 log.error(tree.pos(), "abstract.meth.cant.have.body");
656 } else if ((tree.mods.flags & NATIVE) != 0) {
657 log.error(tree.pos(), "native.meth.cant.have.body");
658 } else {
659 // Add an implicit super() call unless an explicit call to
660 // super(...) or this(...) is given
661 // or we are compiling class java.lang.Object.
662 if (tree.name == names.init && owner.type != syms.objectType) {
663 JCBlock body = tree.body;
664 if (body.stats.isEmpty() ||
665 !TreeInfo.isSelfCall(body.stats.head)) {
666 body.stats = body.stats.
667 prepend(memberEnter.SuperCall(make.at(body.pos),
668 List.<Type>nil(),
669 List.<JCVariableDecl>nil(),
670 false));
671 } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
672 (tree.mods.flags & GENERATEDCONSTR) == 0 &&
673 TreeInfo.isSuperCall(body.stats.head)) {
674 // enum constructors are not allowed to call super
675 // directly, so make sure there aren't any super calls
676 // in enum constructors, except in the compiler
677 // generated one.
678 log.error(tree.body.stats.head.pos(),
679 "call.to.super.not.allowed.in.enum.ctor",
680 env.enclClass.sym);
681 }
682 }
684 // Attribute method body.
685 attribStat(tree.body, localEnv);
686 }
687 localEnv.info.scope.leave();
688 result = tree.type = m.type;
689 chk.validateAnnotations(tree.mods.annotations, m);
691 }
692 finally {
693 chk.setLint(prevLint);
694 }
695 }
697 public void visitVarDef(JCVariableDecl tree) {
698 // Local variables have not been entered yet, so we need to do it now:
699 if (env.info.scope.owner.kind == MTH) {
700 if (tree.sym != null) {
701 // parameters have already been entered
702 env.info.scope.enter(tree.sym);
703 } else {
704 memberEnter.memberEnter(tree, env);
705 annotate.flush();
706 }
707 }
709 VarSymbol v = tree.sym;
710 Lint lint = env.info.lint.augment(v.attributes_field, v.flags());
711 Lint prevLint = chk.setLint(lint);
713 // Check that the variable's declared type is well-formed.
714 chk.validate(tree.vartype, env);
716 try {
717 chk.checkDeprecatedAnnotation(tree.pos(), v);
719 if (tree.init != null) {
720 if ((v.flags_field & FINAL) != 0 && tree.init.getTag() != JCTree.NEWCLASS) {
721 // In this case, `v' is final. Ensure that it's initializer is
722 // evaluated.
723 v.getConstValue(); // ensure initializer is evaluated
724 } else {
725 // Attribute initializer in a new environment
726 // with the declared variable as owner.
727 // Check that initializer conforms to variable's declared type.
728 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
729 initEnv.info.lint = lint;
730 // In order to catch self-references, we set the variable's
731 // declaration position to maximal possible value, effectively
732 // marking the variable as undefined.
733 initEnv.info.enclVar = v;
734 attribExpr(tree.init, initEnv, v.type);
735 }
736 }
737 result = tree.type = v.type;
738 chk.validateAnnotations(tree.mods.annotations, v);
739 }
740 finally {
741 chk.setLint(prevLint);
742 }
743 }
745 public void visitSkip(JCSkip tree) {
746 result = null;
747 }
749 public void visitBlock(JCBlock tree) {
750 if (env.info.scope.owner.kind == TYP) {
751 // Block is a static or instance initializer;
752 // let the owner of the environment be a freshly
753 // created BLOCK-method.
754 Env<AttrContext> localEnv =
755 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
756 localEnv.info.scope.owner =
757 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
758 env.info.scope.owner);
759 if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
760 attribStats(tree.stats, localEnv);
761 } else {
762 // Create a new local environment with a local scope.
763 Env<AttrContext> localEnv =
764 env.dup(tree, env.info.dup(env.info.scope.dup()));
765 attribStats(tree.stats, localEnv);
766 localEnv.info.scope.leave();
767 }
768 result = null;
769 }
771 public void visitDoLoop(JCDoWhileLoop tree) {
772 attribStat(tree.body, env.dup(tree));
773 attribExpr(tree.cond, env, syms.booleanType);
774 result = null;
775 }
777 public void visitWhileLoop(JCWhileLoop tree) {
778 attribExpr(tree.cond, env, syms.booleanType);
779 attribStat(tree.body, env.dup(tree));
780 result = null;
781 }
783 public void visitForLoop(JCForLoop tree) {
784 Env<AttrContext> loopEnv =
785 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
786 attribStats(tree.init, loopEnv);
787 if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
788 loopEnv.tree = tree; // before, we were not in loop!
789 attribStats(tree.step, loopEnv);
790 attribStat(tree.body, loopEnv);
791 loopEnv.info.scope.leave();
792 result = null;
793 }
795 public void visitForeachLoop(JCEnhancedForLoop tree) {
796 Env<AttrContext> loopEnv =
797 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
798 attribStat(tree.var, loopEnv);
799 Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
800 chk.checkNonVoid(tree.pos(), exprType);
801 Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
802 if (elemtype == null) {
803 // or perhaps expr implements Iterable<T>?
804 Type base = types.asSuper(exprType, syms.iterableType.tsym);
805 if (base == null) {
806 log.error(tree.expr.pos(), "foreach.not.applicable.to.type");
807 elemtype = types.createErrorType(exprType);
808 } else {
809 List<Type> iterableParams = base.allparams();
810 elemtype = iterableParams.isEmpty()
811 ? syms.objectType
812 : types.upperBound(iterableParams.head);
813 }
814 }
815 chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
816 loopEnv.tree = tree; // before, we were not in loop!
817 attribStat(tree.body, loopEnv);
818 loopEnv.info.scope.leave();
819 result = null;
820 }
822 public void visitLabelled(JCLabeledStatement tree) {
823 // Check that label is not used in an enclosing statement
824 Env<AttrContext> env1 = env;
825 while (env1 != null && env1.tree.getTag() != JCTree.CLASSDEF) {
826 if (env1.tree.getTag() == JCTree.LABELLED &&
827 ((JCLabeledStatement) env1.tree).label == tree.label) {
828 log.error(tree.pos(), "label.already.in.use",
829 tree.label);
830 break;
831 }
832 env1 = env1.next;
833 }
835 attribStat(tree.body, env.dup(tree));
836 result = null;
837 }
839 public void visitSwitch(JCSwitch tree) {
840 Type seltype = attribExpr(tree.selector, env);
842 Env<AttrContext> switchEnv =
843 env.dup(tree, env.info.dup(env.info.scope.dup()));
845 boolean enumSwitch =
846 allowEnums &&
847 (seltype.tsym.flags() & Flags.ENUM) != 0;
848 if (!enumSwitch)
849 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
851 // Attribute all cases and
852 // check that there are no duplicate case labels or default clauses.
853 Set<Object> labels = new HashSet<Object>(); // The set of case labels.
854 boolean hasDefault = false; // Is there a default label?
855 for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
856 JCCase c = l.head;
857 Env<AttrContext> caseEnv =
858 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
859 if (c.pat != null) {
860 if (enumSwitch) {
861 Symbol sym = enumConstant(c.pat, seltype);
862 if (sym == null) {
863 log.error(c.pat.pos(), "enum.const.req");
864 } else if (!labels.add(sym)) {
865 log.error(c.pos(), "duplicate.case.label");
866 }
867 } else {
868 Type pattype = attribExpr(c.pat, switchEnv, seltype);
869 if (pattype.tag != ERROR) {
870 if (pattype.constValue() == null) {
871 log.error(c.pat.pos(), "const.expr.req");
872 } else if (labels.contains(pattype.constValue())) {
873 log.error(c.pos(), "duplicate.case.label");
874 } else {
875 labels.add(pattype.constValue());
876 }
877 }
878 }
879 } else if (hasDefault) {
880 log.error(c.pos(), "duplicate.default.label");
881 } else {
882 hasDefault = true;
883 }
884 attribStats(c.stats, caseEnv);
885 caseEnv.info.scope.leave();
886 addVars(c.stats, switchEnv.info.scope);
887 }
889 switchEnv.info.scope.leave();
890 result = null;
891 }
892 // where
893 /** Add any variables defined in stats to the switch scope. */
894 private static void addVars(List<JCStatement> stats, Scope switchScope) {
895 for (;stats.nonEmpty(); stats = stats.tail) {
896 JCTree stat = stats.head;
897 if (stat.getTag() == JCTree.VARDEF)
898 switchScope.enter(((JCVariableDecl) stat).sym);
899 }
900 }
901 // where
902 /** Return the selected enumeration constant symbol, or null. */
903 private Symbol enumConstant(JCTree tree, Type enumType) {
904 if (tree.getTag() != JCTree.IDENT) {
905 log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
906 return syms.errSymbol;
907 }
908 JCIdent ident = (JCIdent)tree;
909 Name name = ident.name;
910 for (Scope.Entry e = enumType.tsym.members().lookup(name);
911 e.scope != null; e = e.next()) {
912 if (e.sym.kind == VAR) {
913 Symbol s = ident.sym = e.sym;
914 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
915 ident.type = s.type;
916 return ((s.flags_field & Flags.ENUM) == 0)
917 ? null : s;
918 }
919 }
920 return null;
921 }
923 public void visitSynchronized(JCSynchronized tree) {
924 chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
925 attribStat(tree.body, env);
926 result = null;
927 }
929 public void visitTry(JCTry tree) {
930 // Attribute body
931 attribStat(tree.body, env.dup(tree, env.info.dup()));
933 // Attribute catch clauses
934 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
935 JCCatch c = l.head;
936 Env<AttrContext> catchEnv =
937 env.dup(c, env.info.dup(env.info.scope.dup()));
938 Type ctype = attribStat(c.param, catchEnv);
939 if (c.param.type.tsym.kind == Kinds.VAR) {
940 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
941 }
942 chk.checkType(c.param.vartype.pos(),
943 chk.checkClassType(c.param.vartype.pos(), ctype),
944 syms.throwableType);
945 attribStat(c.body, catchEnv);
946 catchEnv.info.scope.leave();
947 }
949 // Attribute finalizer
950 if (tree.finalizer != null) attribStat(tree.finalizer, env);
951 result = null;
952 }
954 public void visitConditional(JCConditional tree) {
955 attribExpr(tree.cond, env, syms.booleanType);
956 attribExpr(tree.truepart, env);
957 attribExpr(tree.falsepart, env);
958 result = check(tree,
959 capture(condType(tree.pos(), tree.cond.type,
960 tree.truepart.type, tree.falsepart.type)),
961 VAL, pkind, pt);
962 }
963 //where
964 /** Compute the type of a conditional expression, after
965 * checking that it exists. See Spec 15.25.
966 *
967 * @param pos The source position to be used for
968 * error diagnostics.
969 * @param condtype The type of the expression's condition.
970 * @param thentype The type of the expression's then-part.
971 * @param elsetype The type of the expression's else-part.
972 */
973 private Type condType(DiagnosticPosition pos,
974 Type condtype,
975 Type thentype,
976 Type elsetype) {
977 Type ctype = condType1(pos, condtype, thentype, elsetype);
979 // If condition and both arms are numeric constants,
980 // evaluate at compile-time.
981 return ((condtype.constValue() != null) &&
982 (thentype.constValue() != null) &&
983 (elsetype.constValue() != null))
984 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
985 : ctype;
986 }
987 /** Compute the type of a conditional expression, after
988 * checking that it exists. Does not take into
989 * account the special case where condition and both arms
990 * are constants.
991 *
992 * @param pos The source position to be used for error
993 * diagnostics.
994 * @param condtype The type of the expression's condition.
995 * @param thentype The type of the expression's then-part.
996 * @param elsetype The type of the expression's else-part.
997 */
998 private Type condType1(DiagnosticPosition pos, Type condtype,
999 Type thentype, Type elsetype) {
1000 // If same type, that is the result
1001 if (types.isSameType(thentype, elsetype))
1002 return thentype.baseType();
1004 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1005 ? thentype : types.unboxedType(thentype);
1006 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1007 ? elsetype : types.unboxedType(elsetype);
1009 // Otherwise, if both arms can be converted to a numeric
1010 // type, return the least numeric type that fits both arms
1011 // (i.e. return larger of the two, or return int if one
1012 // arm is short, the other is char).
1013 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1014 // If one arm has an integer subrange type (i.e., byte,
1015 // short, or char), and the other is an integer constant
1016 // that fits into the subrange, return the subrange type.
1017 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1018 types.isAssignable(elseUnboxed, thenUnboxed))
1019 return thenUnboxed.baseType();
1020 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1021 types.isAssignable(thenUnboxed, elseUnboxed))
1022 return elseUnboxed.baseType();
1024 for (int i = BYTE; i < VOID; i++) {
1025 Type candidate = syms.typeOfTag[i];
1026 if (types.isSubtype(thenUnboxed, candidate) &&
1027 types.isSubtype(elseUnboxed, candidate))
1028 return candidate;
1029 }
1030 }
1032 // Those were all the cases that could result in a primitive
1033 if (allowBoxing) {
1034 if (thentype.isPrimitive())
1035 thentype = types.boxedClass(thentype).type;
1036 if (elsetype.isPrimitive())
1037 elsetype = types.boxedClass(elsetype).type;
1038 }
1040 if (types.isSubtype(thentype, elsetype))
1041 return elsetype.baseType();
1042 if (types.isSubtype(elsetype, thentype))
1043 return thentype.baseType();
1045 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1046 log.error(pos, "neither.conditional.subtype",
1047 thentype, elsetype);
1048 return thentype.baseType();
1049 }
1051 // both are known to be reference types. The result is
1052 // lub(thentype,elsetype). This cannot fail, as it will
1053 // always be possible to infer "Object" if nothing better.
1054 return types.lub(thentype.baseType(), elsetype.baseType());
1055 }
1057 public void visitIf(JCIf tree) {
1058 attribExpr(tree.cond, env, syms.booleanType);
1059 attribStat(tree.thenpart, env);
1060 if (tree.elsepart != null)
1061 attribStat(tree.elsepart, env);
1062 chk.checkEmptyIf(tree);
1063 result = null;
1064 }
1066 public void visitExec(JCExpressionStatement tree) {
1067 attribExpr(tree.expr, env);
1068 result = null;
1069 }
1071 public void visitBreak(JCBreak tree) {
1072 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1073 result = null;
1074 }
1076 public void visitContinue(JCContinue tree) {
1077 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1078 result = null;
1079 }
1080 //where
1081 /** Return the target of a break or continue statement, if it exists,
1082 * report an error if not.
1083 * Note: The target of a labelled break or continue is the
1084 * (non-labelled) statement tree referred to by the label,
1085 * not the tree representing the labelled statement itself.
1086 *
1087 * @param pos The position to be used for error diagnostics
1088 * @param tag The tag of the jump statement. This is either
1089 * Tree.BREAK or Tree.CONTINUE.
1090 * @param label The label of the jump statement, or null if no
1091 * label is given.
1092 * @param env The environment current at the jump statement.
1093 */
1094 private JCTree findJumpTarget(DiagnosticPosition pos,
1095 int tag,
1096 Name label,
1097 Env<AttrContext> env) {
1098 // Search environments outwards from the point of jump.
1099 Env<AttrContext> env1 = env;
1100 LOOP:
1101 while (env1 != null) {
1102 switch (env1.tree.getTag()) {
1103 case JCTree.LABELLED:
1104 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1105 if (label == labelled.label) {
1106 // If jump is a continue, check that target is a loop.
1107 if (tag == JCTree.CONTINUE) {
1108 if (labelled.body.getTag() != JCTree.DOLOOP &&
1109 labelled.body.getTag() != JCTree.WHILELOOP &&
1110 labelled.body.getTag() != JCTree.FORLOOP &&
1111 labelled.body.getTag() != JCTree.FOREACHLOOP)
1112 log.error(pos, "not.loop.label", label);
1113 // Found labelled statement target, now go inwards
1114 // to next non-labelled tree.
1115 return TreeInfo.referencedStatement(labelled);
1116 } else {
1117 return labelled;
1118 }
1119 }
1120 break;
1121 case JCTree.DOLOOP:
1122 case JCTree.WHILELOOP:
1123 case JCTree.FORLOOP:
1124 case JCTree.FOREACHLOOP:
1125 if (label == null) return env1.tree;
1126 break;
1127 case JCTree.SWITCH:
1128 if (label == null && tag == JCTree.BREAK) return env1.tree;
1129 break;
1130 case JCTree.METHODDEF:
1131 case JCTree.CLASSDEF:
1132 break LOOP;
1133 default:
1134 }
1135 env1 = env1.next;
1136 }
1137 if (label != null)
1138 log.error(pos, "undef.label", label);
1139 else if (tag == JCTree.CONTINUE)
1140 log.error(pos, "cont.outside.loop");
1141 else
1142 log.error(pos, "break.outside.switch.loop");
1143 return null;
1144 }
1146 public void visitReturn(JCReturn tree) {
1147 // Check that there is an enclosing method which is
1148 // nested within than the enclosing class.
1149 if (env.enclMethod == null ||
1150 env.enclMethod.sym.owner != env.enclClass.sym) {
1151 log.error(tree.pos(), "ret.outside.meth");
1153 } else {
1154 // Attribute return expression, if it exists, and check that
1155 // it conforms to result type of enclosing method.
1156 Symbol m = env.enclMethod.sym;
1157 if (m.type.getReturnType().tag == VOID) {
1158 if (tree.expr != null)
1159 log.error(tree.expr.pos(),
1160 "cant.ret.val.from.meth.decl.void");
1161 } else if (tree.expr == null) {
1162 log.error(tree.pos(), "missing.ret.val");
1163 } else {
1164 attribExpr(tree.expr, env, m.type.getReturnType());
1165 }
1166 }
1167 result = null;
1168 }
1170 public void visitThrow(JCThrow tree) {
1171 attribExpr(tree.expr, env, syms.throwableType);
1172 result = null;
1173 }
1175 public void visitAssert(JCAssert tree) {
1176 attribExpr(tree.cond, env, syms.booleanType);
1177 if (tree.detail != null) {
1178 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1179 }
1180 result = null;
1181 }
1183 /** Visitor method for method invocations.
1184 * NOTE: The method part of an application will have in its type field
1185 * the return type of the method, not the method's type itself!
1186 */
1187 public void visitApply(JCMethodInvocation tree) {
1188 // The local environment of a method application is
1189 // a new environment nested in the current one.
1190 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1192 // The types of the actual method arguments.
1193 List<Type> argtypes;
1195 // The types of the actual method type arguments.
1196 List<Type> typeargtypes = null;
1198 Name methName = TreeInfo.name(tree.meth);
1200 boolean isConstructorCall =
1201 methName == names._this || methName == names._super;
1203 if (isConstructorCall) {
1204 // We are seeing a ...this(...) or ...super(...) call.
1205 // Check that this is the first statement in a constructor.
1206 if (checkFirstConstructorStat(tree, env)) {
1208 // Record the fact
1209 // that this is a constructor call (using isSelfCall).
1210 localEnv.info.isSelfCall = true;
1212 // Attribute arguments, yielding list of argument types.
1213 argtypes = attribArgs(tree.args, localEnv);
1214 typeargtypes = attribTypes(tree.typeargs, localEnv);
1216 // Variable `site' points to the class in which the called
1217 // constructor is defined.
1218 Type site = env.enclClass.sym.type;
1219 if (methName == names._super) {
1220 if (site == syms.objectType) {
1221 log.error(tree.meth.pos(), "no.superclass", site);
1222 site = types.createErrorType(syms.objectType);
1223 } else {
1224 site = types.supertype(site);
1225 }
1226 }
1228 if (site.tag == CLASS) {
1229 if (site.getEnclosingType().tag == CLASS) {
1230 // we are calling a nested class
1232 if (tree.meth.getTag() == JCTree.SELECT) {
1233 JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1235 // We are seeing a prefixed call, of the form
1236 // <expr>.super(...).
1237 // Check that the prefix expression conforms
1238 // to the outer instance type of the class.
1239 chk.checkRefType(qualifier.pos(),
1240 attribExpr(qualifier, localEnv,
1241 site.getEnclosingType()));
1242 } else if (methName == names._super) {
1243 // qualifier omitted; check for existence
1244 // of an appropriate implicit qualifier.
1245 rs.resolveImplicitThis(tree.meth.pos(),
1246 localEnv, site);
1247 }
1248 } else if (tree.meth.getTag() == JCTree.SELECT) {
1249 log.error(tree.meth.pos(), "illegal.qual.not.icls",
1250 site.tsym);
1251 }
1253 // if we're calling a java.lang.Enum constructor,
1254 // prefix the implicit String and int parameters
1255 if (site.tsym == syms.enumSym && allowEnums)
1256 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1258 // Resolve the called constructor under the assumption
1259 // that we are referring to a superclass instance of the
1260 // current instance (JLS ???).
1261 boolean selectSuperPrev = localEnv.info.selectSuper;
1262 localEnv.info.selectSuper = true;
1263 localEnv.info.varArgs = false;
1264 Symbol sym = rs.resolveConstructor(
1265 tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1266 localEnv.info.selectSuper = selectSuperPrev;
1268 // Set method symbol to resolved constructor...
1269 TreeInfo.setSymbol(tree.meth, sym);
1271 // ...and check that it is legal in the current context.
1272 // (this will also set the tree's type)
1273 Type mpt = newMethTemplate(argtypes, typeargtypes);
1274 checkId(tree.meth, site, sym, localEnv, MTH,
1275 mpt, tree.varargsElement != null);
1276 }
1277 // Otherwise, `site' is an error type and we do nothing
1278 }
1279 result = tree.type = syms.voidType;
1280 } else {
1281 // Otherwise, we are seeing a regular method call.
1282 // Attribute the arguments, yielding list of argument types, ...
1283 argtypes = attribArgs(tree.args, localEnv);
1284 typeargtypes = attribTypes(tree.typeargs, localEnv);
1286 // ... and attribute the method using as a prototype a methodtype
1287 // whose formal argument types is exactly the list of actual
1288 // arguments (this will also set the method symbol).
1289 Type mpt = newMethTemplate(argtypes, typeargtypes);
1290 localEnv.info.varArgs = false;
1291 Type mtype = attribExpr(tree.meth, localEnv, mpt);
1292 if (localEnv.info.varArgs)
1293 assert mtype.isErroneous() || tree.varargsElement != null;
1295 // Compute the result type.
1296 Type restype = mtype.getReturnType();
1297 assert restype.tag != WILDCARD : mtype;
1299 // as a special case, array.clone() has a result that is
1300 // the same as static type of the array being cloned
1301 if (tree.meth.getTag() == JCTree.SELECT &&
1302 allowCovariantReturns &&
1303 methName == names.clone &&
1304 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1305 restype = ((JCFieldAccess) tree.meth).selected.type;
1307 // as a special case, x.getClass() has type Class<? extends |X|>
1308 if (allowGenerics &&
1309 methName == names.getClass && tree.args.isEmpty()) {
1310 Type qualifier = (tree.meth.getTag() == JCTree.SELECT)
1311 ? ((JCFieldAccess) tree.meth).selected.type
1312 : env.enclClass.sym.type;
1313 restype = new
1314 ClassType(restype.getEnclosingType(),
1315 List.<Type>of(new WildcardType(types.erasure(qualifier),
1316 BoundKind.EXTENDS,
1317 syms.boundClass)),
1318 restype.tsym);
1319 }
1321 // Check that value of resulting type is admissible in the
1322 // current context. Also, capture the return type
1323 result = check(tree, capture(restype), VAL, pkind, pt);
1324 }
1325 chk.validate(tree.typeargs, localEnv);
1326 }
1327 //where
1328 /** Check that given application node appears as first statement
1329 * in a constructor call.
1330 * @param tree The application node
1331 * @param env The environment current at the application.
1332 */
1333 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1334 JCMethodDecl enclMethod = env.enclMethod;
1335 if (enclMethod != null && enclMethod.name == names.init) {
1336 JCBlock body = enclMethod.body;
1337 if (body.stats.head.getTag() == JCTree.EXEC &&
1338 ((JCExpressionStatement) body.stats.head).expr == tree)
1339 return true;
1340 }
1341 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1342 TreeInfo.name(tree.meth));
1343 return false;
1344 }
1346 /** Obtain a method type with given argument types.
1347 */
1348 Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
1349 MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
1350 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1351 }
1353 public void visitNewClass(JCNewClass tree) {
1354 Type owntype = types.createErrorType(tree.type);
1356 // The local environment of a class creation is
1357 // a new environment nested in the current one.
1358 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1360 // The anonymous inner class definition of the new expression,
1361 // if one is defined by it.
1362 JCClassDecl cdef = tree.def;
1364 // If enclosing class is given, attribute it, and
1365 // complete class name to be fully qualified
1366 JCExpression clazz = tree.clazz; // Class field following new
1367 JCExpression clazzid = // Identifier in class field
1368 (clazz.getTag() == JCTree.TYPEAPPLY)
1369 ? ((JCTypeApply) clazz).clazz
1370 : clazz;
1372 JCExpression clazzid1 = clazzid; // The same in fully qualified form
1374 if (tree.encl != null) {
1375 // We are seeing a qualified new, of the form
1376 // <expr>.new C <...> (...) ...
1377 // In this case, we let clazz stand for the name of the
1378 // allocated class C prefixed with the type of the qualifier
1379 // expression, so that we can
1380 // resolve it with standard techniques later. I.e., if
1381 // <expr> has type T, then <expr>.new C <...> (...)
1382 // yields a clazz T.C.
1383 Type encltype = chk.checkRefType(tree.encl.pos(),
1384 attribExpr(tree.encl, env));
1385 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1386 ((JCIdent) clazzid).name);
1387 if (clazz.getTag() == JCTree.TYPEAPPLY)
1388 clazz = make.at(tree.pos).
1389 TypeApply(clazzid1,
1390 ((JCTypeApply) clazz).arguments);
1391 else
1392 clazz = clazzid1;
1393 // System.out.println(clazz + " generated.");//DEBUG
1394 }
1396 // Attribute clazz expression and store
1397 // symbol + type back into the attributed tree.
1398 Type clazztype = chk.checkClassType(
1399 tree.clazz.pos(), attribType(clazz, env), true);
1400 chk.validate(clazz, localEnv);
1401 if (tree.encl != null) {
1402 // We have to work in this case to store
1403 // symbol + type back into the attributed tree.
1404 tree.clazz.type = clazztype;
1405 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1406 clazzid.type = ((JCIdent) clazzid).sym.type;
1407 if (!clazztype.isErroneous()) {
1408 if (cdef != null && clazztype.tsym.isInterface()) {
1409 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1410 } else if (clazztype.tsym.isStatic()) {
1411 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1412 }
1413 }
1414 } else if (!clazztype.tsym.isInterface() &&
1415 clazztype.getEnclosingType().tag == CLASS) {
1416 // Check for the existence of an apropos outer instance
1417 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1418 }
1420 // Attribute constructor arguments.
1421 List<Type> argtypes = attribArgs(tree.args, localEnv);
1422 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1424 // If we have made no mistakes in the class type...
1425 if (clazztype.tag == CLASS) {
1426 // Enums may not be instantiated except implicitly
1427 if (allowEnums &&
1428 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1429 (env.tree.getTag() != JCTree.VARDEF ||
1430 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1431 ((JCVariableDecl) env.tree).init != tree))
1432 log.error(tree.pos(), "enum.cant.be.instantiated");
1433 // Check that class is not abstract
1434 if (cdef == null &&
1435 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1436 log.error(tree.pos(), "abstract.cant.be.instantiated",
1437 clazztype.tsym);
1438 } else if (cdef != null && clazztype.tsym.isInterface()) {
1439 // Check that no constructor arguments are given to
1440 // anonymous classes implementing an interface
1441 if (!argtypes.isEmpty())
1442 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1444 if (!typeargtypes.isEmpty())
1445 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1447 // Error recovery: pretend no arguments were supplied.
1448 argtypes = List.nil();
1449 typeargtypes = List.nil();
1450 }
1452 // Resolve the called constructor under the assumption
1453 // that we are referring to a superclass instance of the
1454 // current instance (JLS ???).
1455 else {
1456 localEnv.info.selectSuper = cdef != null;
1457 localEnv.info.varArgs = false;
1458 tree.constructor = rs.resolveConstructor(
1459 tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
1460 tree.constructorType = checkMethod(clazztype,
1461 tree.constructor,
1462 localEnv,
1463 tree.args,
1464 argtypes,
1465 typeargtypes,
1466 localEnv.info.varArgs);
1467 if (localEnv.info.varArgs)
1468 assert tree.constructorType.isErroneous() || tree.varargsElement != null;
1469 }
1471 if (cdef != null) {
1472 // We are seeing an anonymous class instance creation.
1473 // In this case, the class instance creation
1474 // expression
1475 //
1476 // E.new <typeargs1>C<typargs2>(args) { ... }
1477 //
1478 // is represented internally as
1479 //
1480 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1481 //
1482 // This expression is then *transformed* as follows:
1483 //
1484 // (1) add a STATIC flag to the class definition
1485 // if the current environment is static
1486 // (2) add an extends or implements clause
1487 // (3) add a constructor.
1488 //
1489 // For instance, if C is a class, and ET is the type of E,
1490 // the expression
1491 //
1492 // E.new <typeargs1>C<typargs2>(args) { ... }
1493 //
1494 // is translated to (where X is a fresh name and typarams is the
1495 // parameter list of the super constructor):
1496 //
1497 // new <typeargs1>X(<*nullchk*>E, args) where
1498 // X extends C<typargs2> {
1499 // <typarams> X(ET e, args) {
1500 // e.<typeargs1>super(args)
1501 // }
1502 // ...
1503 // }
1504 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1506 if (clazztype.tsym.isInterface()) {
1507 cdef.implementing = List.of(clazz);
1508 } else {
1509 cdef.extending = clazz;
1510 }
1512 attribStat(cdef, localEnv);
1514 // If an outer instance is given,
1515 // prefix it to the constructor arguments
1516 // and delete it from the new expression
1517 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1518 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1519 argtypes = argtypes.prepend(tree.encl.type);
1520 tree.encl = null;
1521 }
1523 // Reassign clazztype and recompute constructor.
1524 clazztype = cdef.sym.type;
1525 Symbol sym = rs.resolveConstructor(
1526 tree.pos(), localEnv, clazztype, argtypes,
1527 typeargtypes, true, tree.varargsElement != null);
1528 assert sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous();
1529 tree.constructor = sym;
1530 tree.constructorType = checkMethod(clazztype,
1531 tree.constructor,
1532 localEnv,
1533 tree.args,
1534 argtypes,
1535 typeargtypes,
1536 localEnv.info.varArgs);
1537 }
1539 if (tree.constructor != null && tree.constructor.kind == MTH)
1540 owntype = clazztype;
1541 }
1542 result = check(tree, owntype, VAL, pkind, pt);
1543 chk.validate(tree.typeargs, localEnv);
1544 }
1546 /** Make an attributed null check tree.
1547 */
1548 public JCExpression makeNullCheck(JCExpression arg) {
1549 // optimization: X.this is never null; skip null check
1550 Name name = TreeInfo.name(arg);
1551 if (name == names._this || name == names._super) return arg;
1553 int optag = JCTree.NULLCHK;
1554 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1555 tree.operator = syms.nullcheck;
1556 tree.type = arg.type;
1557 return tree;
1558 }
1560 public void visitNewArray(JCNewArray tree) {
1561 Type owntype = types.createErrorType(tree.type);
1562 Type elemtype;
1563 if (tree.elemtype != null) {
1564 elemtype = attribType(tree.elemtype, env);
1565 chk.validate(tree.elemtype, env);
1566 owntype = elemtype;
1567 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1568 attribExpr(l.head, env, syms.intType);
1569 owntype = new ArrayType(owntype, syms.arrayClass);
1570 }
1571 } else {
1572 // we are seeing an untyped aggregate { ... }
1573 // this is allowed only if the prototype is an array
1574 if (pt.tag == ARRAY) {
1575 elemtype = types.elemtype(pt);
1576 } else {
1577 if (pt.tag != ERROR) {
1578 log.error(tree.pos(), "illegal.initializer.for.type",
1579 pt);
1580 }
1581 elemtype = types.createErrorType(pt);
1582 }
1583 }
1584 if (tree.elems != null) {
1585 attribExprs(tree.elems, env, elemtype);
1586 owntype = new ArrayType(elemtype, syms.arrayClass);
1587 }
1588 if (!types.isReifiable(elemtype))
1589 log.error(tree.pos(), "generic.array.creation");
1590 result = check(tree, owntype, VAL, pkind, pt);
1591 }
1593 public void visitParens(JCParens tree) {
1594 Type owntype = attribTree(tree.expr, env, pkind, pt);
1595 result = check(tree, owntype, pkind, pkind, pt);
1596 Symbol sym = TreeInfo.symbol(tree);
1597 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1598 log.error(tree.pos(), "illegal.start.of.type");
1599 }
1601 public void visitAssign(JCAssign tree) {
1602 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1603 Type capturedType = capture(owntype);
1604 attribExpr(tree.rhs, env, owntype);
1605 result = check(tree, capturedType, VAL, pkind, pt);
1606 }
1608 public void visitAssignop(JCAssignOp tree) {
1609 // Attribute arguments.
1610 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
1611 Type operand = attribExpr(tree.rhs, env);
1612 // Find operator.
1613 Symbol operator = tree.operator = rs.resolveBinaryOperator(
1614 tree.pos(), tree.getTag() - JCTree.ASGOffset, env,
1615 owntype, operand);
1617 if (operator.kind == MTH) {
1618 chk.checkOperator(tree.pos(),
1619 (OperatorSymbol)operator,
1620 tree.getTag() - JCTree.ASGOffset,
1621 owntype,
1622 operand);
1623 chk.checkDivZero(tree.rhs.pos(), operator, operand);
1624 chk.checkCastable(tree.rhs.pos(),
1625 operator.type.getReturnType(),
1626 owntype);
1627 }
1628 result = check(tree, owntype, VAL, pkind, pt);
1629 }
1631 public void visitUnary(JCUnary tree) {
1632 // Attribute arguments.
1633 Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1634 ? attribTree(tree.arg, env, VAR, Type.noType)
1635 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
1637 // Find operator.
1638 Symbol operator = tree.operator =
1639 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
1641 Type owntype = types.createErrorType(tree.type);
1642 if (operator.kind == MTH) {
1643 owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1644 ? tree.arg.type
1645 : operator.type.getReturnType();
1646 int opc = ((OperatorSymbol)operator).opcode;
1648 // If the argument is constant, fold it.
1649 if (argtype.constValue() != null) {
1650 Type ctype = cfolder.fold1(opc, argtype);
1651 if (ctype != null) {
1652 owntype = cfolder.coerce(ctype, owntype);
1654 // Remove constant types from arguments to
1655 // conserve space. The parser will fold concatenations
1656 // of string literals; the code here also
1657 // gets rid of intermediate results when some of the
1658 // operands are constant identifiers.
1659 if (tree.arg.type.tsym == syms.stringType.tsym) {
1660 tree.arg.type = syms.stringType;
1661 }
1662 }
1663 }
1664 }
1665 result = check(tree, owntype, VAL, pkind, pt);
1666 }
1668 public void visitBinary(JCBinary tree) {
1669 // Attribute arguments.
1670 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
1671 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
1673 // Find operator.
1674 Symbol operator = tree.operator =
1675 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
1677 Type owntype = types.createErrorType(tree.type);
1678 if (operator.kind == MTH) {
1679 owntype = operator.type.getReturnType();
1680 int opc = chk.checkOperator(tree.lhs.pos(),
1681 (OperatorSymbol)operator,
1682 tree.getTag(),
1683 left,
1684 right);
1686 // If both arguments are constants, fold them.
1687 if (left.constValue() != null && right.constValue() != null) {
1688 Type ctype = cfolder.fold2(opc, left, right);
1689 if (ctype != null) {
1690 owntype = cfolder.coerce(ctype, owntype);
1692 // Remove constant types from arguments to
1693 // conserve space. The parser will fold concatenations
1694 // of string literals; the code here also
1695 // gets rid of intermediate results when some of the
1696 // operands are constant identifiers.
1697 if (tree.lhs.type.tsym == syms.stringType.tsym) {
1698 tree.lhs.type = syms.stringType;
1699 }
1700 if (tree.rhs.type.tsym == syms.stringType.tsym) {
1701 tree.rhs.type = syms.stringType;
1702 }
1703 }
1704 }
1706 // Check that argument types of a reference ==, != are
1707 // castable to each other, (JLS???).
1708 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
1709 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
1710 log.error(tree.pos(), "incomparable.types", left, right);
1711 }
1712 }
1714 chk.checkDivZero(tree.rhs.pos(), operator, right);
1715 }
1716 result = check(tree, owntype, VAL, pkind, pt);
1717 }
1719 public void visitTypeCast(JCTypeCast tree) {
1720 Type clazztype = attribType(tree.clazz, env);
1721 chk.validate(tree.clazz, env);
1722 Type exprtype = attribExpr(tree.expr, env, Infer.anyPoly);
1723 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1724 if (exprtype.constValue() != null)
1725 owntype = cfolder.coerce(exprtype, owntype);
1726 result = check(tree, capture(owntype), VAL, pkind, pt);
1727 }
1729 public void visitTypeTest(JCInstanceOf tree) {
1730 Type exprtype = chk.checkNullOrRefType(
1731 tree.expr.pos(), attribExpr(tree.expr, env));
1732 Type clazztype = chk.checkReifiableReferenceType(
1733 tree.clazz.pos(), attribType(tree.clazz, env));
1734 chk.validate(tree.clazz, env);
1735 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1736 result = check(tree, syms.booleanType, VAL, pkind, pt);
1737 }
1739 public void visitIndexed(JCArrayAccess tree) {
1740 Type owntype = types.createErrorType(tree.type);
1741 Type atype = attribExpr(tree.indexed, env);
1742 attribExpr(tree.index, env, syms.intType);
1743 if (types.isArray(atype))
1744 owntype = types.elemtype(atype);
1745 else if (atype.tag != ERROR)
1746 log.error(tree.pos(), "array.req.but.found", atype);
1747 if ((pkind & VAR) == 0) owntype = capture(owntype);
1748 result = check(tree, owntype, VAR, pkind, pt);
1749 }
1751 public void visitIdent(JCIdent tree) {
1752 Symbol sym;
1753 boolean varArgs = false;
1755 // Find symbol
1756 if (pt.tag == METHOD || pt.tag == FORALL) {
1757 // If we are looking for a method, the prototype `pt' will be a
1758 // method type with the type of the call's arguments as parameters.
1759 env.info.varArgs = false;
1760 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
1761 varArgs = env.info.varArgs;
1762 } else if (tree.sym != null && tree.sym.kind != VAR) {
1763 sym = tree.sym;
1764 } else {
1765 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
1766 }
1767 tree.sym = sym;
1769 // (1) Also find the environment current for the class where
1770 // sym is defined (`symEnv').
1771 // Only for pre-tiger versions (1.4 and earlier):
1772 // (2) Also determine whether we access symbol out of an anonymous
1773 // class in a this or super call. This is illegal for instance
1774 // members since such classes don't carry a this$n link.
1775 // (`noOuterThisPath').
1776 Env<AttrContext> symEnv = env;
1777 boolean noOuterThisPath = false;
1778 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
1779 (sym.kind & (VAR | MTH | TYP)) != 0 &&
1780 sym.owner.kind == TYP &&
1781 tree.name != names._this && tree.name != names._super) {
1783 // Find environment in which identifier is defined.
1784 while (symEnv.outer != null &&
1785 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
1786 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
1787 noOuterThisPath = !allowAnonOuterThis;
1788 symEnv = symEnv.outer;
1789 }
1790 }
1792 // If symbol is a variable, ...
1793 if (sym.kind == VAR) {
1794 VarSymbol v = (VarSymbol)sym;
1796 // ..., evaluate its initializer, if it has one, and check for
1797 // illegal forward reference.
1798 checkInit(tree, env, v, false);
1800 // If symbol is a local variable accessed from an embedded
1801 // inner class check that it is final.
1802 if (v.owner.kind == MTH &&
1803 v.owner != env.info.scope.owner &&
1804 (v.flags_field & FINAL) == 0) {
1805 log.error(tree.pos(),
1806 "local.var.accessed.from.icls.needs.final",
1807 v);
1808 }
1810 // If we are expecting a variable (as opposed to a value), check
1811 // that the variable is assignable in the current environment.
1812 if (pkind == VAR)
1813 checkAssignable(tree.pos(), v, null, env);
1814 }
1816 // In a constructor body,
1817 // if symbol is a field or instance method, check that it is
1818 // not accessed before the supertype constructor is called.
1819 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
1820 (sym.kind & (VAR | MTH)) != 0 &&
1821 sym.owner.kind == TYP &&
1822 (sym.flags() & STATIC) == 0) {
1823 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
1824 }
1825 Env<AttrContext> env1 = env;
1826 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
1827 // If the found symbol is inaccessible, then it is
1828 // accessed through an enclosing instance. Locate this
1829 // enclosing instance:
1830 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
1831 env1 = env1.outer;
1832 }
1833 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
1834 }
1836 public void visitSelect(JCFieldAccess tree) {
1837 // Determine the expected kind of the qualifier expression.
1838 int skind = 0;
1839 if (tree.name == names._this || tree.name == names._super ||
1840 tree.name == names._class)
1841 {
1842 skind = TYP;
1843 } else {
1844 if ((pkind & PCK) != 0) skind = skind | PCK;
1845 if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
1846 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
1847 }
1849 // Attribute the qualifier expression, and determine its symbol (if any).
1850 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
1851 if ((pkind & (PCK | TYP)) == 0)
1852 site = capture(site); // Capture field access
1854 // don't allow T.class T[].class, etc
1855 if (skind == TYP) {
1856 Type elt = site;
1857 while (elt.tag == ARRAY)
1858 elt = ((ArrayType)elt).elemtype;
1859 if (elt.tag == TYPEVAR) {
1860 log.error(tree.pos(), "type.var.cant.be.deref");
1861 result = types.createErrorType(tree.type);
1862 return;
1863 }
1864 }
1866 // If qualifier symbol is a type or `super', assert `selectSuper'
1867 // for the selection. This is relevant for determining whether
1868 // protected symbols are accessible.
1869 Symbol sitesym = TreeInfo.symbol(tree.selected);
1870 boolean selectSuperPrev = env.info.selectSuper;
1871 env.info.selectSuper =
1872 sitesym != null &&
1873 sitesym.name == names._super;
1875 // If selected expression is polymorphic, strip
1876 // type parameters and remember in env.info.tvars, so that
1877 // they can be added later (in Attr.checkId and Infer.instantiateMethod).
1878 if (tree.selected.type.tag == FORALL) {
1879 ForAll pstype = (ForAll)tree.selected.type;
1880 env.info.tvars = pstype.tvars;
1881 site = tree.selected.type = pstype.qtype;
1882 }
1884 // Determine the symbol represented by the selection.
1885 env.info.varArgs = false;
1886 Symbol sym = selectSym(tree, site, env, pt, pkind);
1887 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
1888 site = capture(site);
1889 sym = selectSym(tree, site, env, pt, pkind);
1890 }
1891 boolean varArgs = env.info.varArgs;
1892 tree.sym = sym;
1894 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
1895 while (site.tag == TYPEVAR) site = site.getUpperBound();
1896 site = capture(site);
1897 }
1899 // If that symbol is a variable, ...
1900 if (sym.kind == VAR) {
1901 VarSymbol v = (VarSymbol)sym;
1903 // ..., evaluate its initializer, if it has one, and check for
1904 // illegal forward reference.
1905 checkInit(tree, env, v, true);
1907 // If we are expecting a variable (as opposed to a value), check
1908 // that the variable is assignable in the current environment.
1909 if (pkind == VAR)
1910 checkAssignable(tree.pos(), v, tree.selected, env);
1911 }
1913 // Disallow selecting a type from an expression
1914 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
1915 tree.type = check(tree.selected, pt,
1916 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
1917 }
1919 if (isType(sitesym)) {
1920 if (sym.name == names._this) {
1921 // If `C' is the currently compiled class, check that
1922 // C.this' does not appear in a call to a super(...)
1923 if (env.info.isSelfCall &&
1924 site.tsym == env.enclClass.sym) {
1925 chk.earlyRefError(tree.pos(), sym);
1926 }
1927 } else {
1928 // Check if type-qualified fields or methods are static (JLS)
1929 if ((sym.flags() & STATIC) == 0 &&
1930 sym.name != names._super &&
1931 (sym.kind == VAR || sym.kind == MTH)) {
1932 rs.access(rs.new StaticError(sym),
1933 tree.pos(), site, sym.name, true);
1934 }
1935 }
1936 }
1938 // If we are selecting an instance member via a `super', ...
1939 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
1941 // Check that super-qualified symbols are not abstract (JLS)
1942 rs.checkNonAbstract(tree.pos(), sym);
1944 if (site.isRaw()) {
1945 // Determine argument types for site.
1946 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
1947 if (site1 != null) site = site1;
1948 }
1949 }
1951 env.info.selectSuper = selectSuperPrev;
1952 result = checkId(tree, site, sym, env, pkind, pt, varArgs);
1953 env.info.tvars = List.nil();
1954 }
1955 //where
1956 /** Determine symbol referenced by a Select expression,
1957 *
1958 * @param tree The select tree.
1959 * @param site The type of the selected expression,
1960 * @param env The current environment.
1961 * @param pt The current prototype.
1962 * @param pkind The expected kind(s) of the Select expression.
1963 */
1964 private Symbol selectSym(JCFieldAccess tree,
1965 Type site,
1966 Env<AttrContext> env,
1967 Type pt,
1968 int pkind) {
1969 DiagnosticPosition pos = tree.pos();
1970 Name name = tree.name;
1972 switch (site.tag) {
1973 case PACKAGE:
1974 return rs.access(
1975 rs.findIdentInPackage(env, site.tsym, name, pkind),
1976 pos, site, name, true);
1977 case ARRAY:
1978 case CLASS:
1979 if (pt.tag == METHOD || pt.tag == FORALL) {
1980 return rs.resolveQualifiedMethod(
1981 pos, env, site, name, pt.getParameterTypes(), pt.getTypeArguments());
1982 } else if (name == names._this || name == names._super) {
1983 return rs.resolveSelf(pos, env, site.tsym, name);
1984 } else if (name == names._class) {
1985 // In this case, we have already made sure in
1986 // visitSelect that qualifier expression is a type.
1987 Type t = syms.classType;
1988 List<Type> typeargs = allowGenerics
1989 ? List.of(types.erasure(site))
1990 : List.<Type>nil();
1991 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
1992 return new VarSymbol(
1993 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
1994 } else {
1995 // We are seeing a plain identifier as selector.
1996 Symbol sym = rs.findIdentInType(env, site, name, pkind);
1997 if ((pkind & ERRONEOUS) == 0)
1998 sym = rs.access(sym, pos, site, name, true);
1999 return sym;
2000 }
2001 case WILDCARD:
2002 throw new AssertionError(tree);
2003 case TYPEVAR:
2004 // Normally, site.getUpperBound() shouldn't be null.
2005 // It should only happen during memberEnter/attribBase
2006 // when determining the super type which *must* be
2007 // done before attributing the type variables. In
2008 // other words, we are seeing this illegal program:
2009 // class B<T> extends A<T.foo> {}
2010 Symbol sym = (site.getUpperBound() != null)
2011 ? selectSym(tree, capture(site.getUpperBound()), env, pt, pkind)
2012 : null;
2013 if (sym == null || isType(sym)) {
2014 log.error(pos, "type.var.cant.be.deref");
2015 return syms.errSymbol;
2016 } else {
2017 Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
2018 rs.new AccessError(env, site, sym) :
2019 sym;
2020 rs.access(sym2, pos, site, name, true);
2021 return sym;
2022 }
2023 case ERROR:
2024 // preserve identifier names through errors
2025 return types.createErrorType(name, site.tsym, site).tsym;
2026 default:
2027 // The qualifier expression is of a primitive type -- only
2028 // .class is allowed for these.
2029 if (name == names._class) {
2030 // In this case, we have already made sure in Select that
2031 // qualifier expression is a type.
2032 Type t = syms.classType;
2033 Type arg = types.boxedClass(site).type;
2034 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2035 return new VarSymbol(
2036 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2037 } else {
2038 log.error(pos, "cant.deref", site);
2039 return syms.errSymbol;
2040 }
2041 }
2042 }
2044 /** Determine type of identifier or select expression and check that
2045 * (1) the referenced symbol is not deprecated
2046 * (2) the symbol's type is safe (@see checkSafe)
2047 * (3) if symbol is a variable, check that its type and kind are
2048 * compatible with the prototype and protokind.
2049 * (4) if symbol is an instance field of a raw type,
2050 * which is being assigned to, issue an unchecked warning if its
2051 * type changes under erasure.
2052 * (5) if symbol is an instance method of a raw type, issue an
2053 * unchecked warning if its argument types change under erasure.
2054 * If checks succeed:
2055 * If symbol is a constant, return its constant type
2056 * else if symbol is a method, return its result type
2057 * otherwise return its type.
2058 * Otherwise return errType.
2059 *
2060 * @param tree The syntax tree representing the identifier
2061 * @param site If this is a select, the type of the selected
2062 * expression, otherwise the type of the current class.
2063 * @param sym The symbol representing the identifier.
2064 * @param env The current environment.
2065 * @param pkind The set of expected kinds.
2066 * @param pt The expected type.
2067 */
2068 Type checkId(JCTree tree,
2069 Type site,
2070 Symbol sym,
2071 Env<AttrContext> env,
2072 int pkind,
2073 Type pt,
2074 boolean useVarargs) {
2075 if (pt.isErroneous()) return types.createErrorType(site);
2076 Type owntype; // The computed type of this identifier occurrence.
2077 switch (sym.kind) {
2078 case TYP:
2079 // For types, the computed type equals the symbol's type,
2080 // except for two situations:
2081 owntype = sym.type;
2082 if (owntype.tag == CLASS) {
2083 Type ownOuter = owntype.getEnclosingType();
2085 // (a) If the symbol's type is parameterized, erase it
2086 // because no type parameters were given.
2087 // We recover generic outer type later in visitTypeApply.
2088 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2089 owntype = types.erasure(owntype);
2090 }
2092 // (b) If the symbol's type is an inner class, then
2093 // we have to interpret its outer type as a superclass
2094 // of the site type. Example:
2095 //
2096 // class Tree<A> { class Visitor { ... } }
2097 // class PointTree extends Tree<Point> { ... }
2098 // ...PointTree.Visitor...
2099 //
2100 // Then the type of the last expression above is
2101 // Tree<Point>.Visitor.
2102 else if (ownOuter.tag == CLASS && site != ownOuter) {
2103 Type normOuter = site;
2104 if (normOuter.tag == CLASS)
2105 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2106 if (normOuter == null) // perhaps from an import
2107 normOuter = types.erasure(ownOuter);
2108 if (normOuter != ownOuter)
2109 owntype = new ClassType(
2110 normOuter, List.<Type>nil(), owntype.tsym);
2111 }
2112 }
2113 break;
2114 case VAR:
2115 VarSymbol v = (VarSymbol)sym;
2116 // Test (4): if symbol is an instance field of a raw type,
2117 // which is being assigned to, issue an unchecked warning if
2118 // its type changes under erasure.
2119 if (allowGenerics &&
2120 pkind == VAR &&
2121 v.owner.kind == TYP &&
2122 (v.flags() & STATIC) == 0 &&
2123 (site.tag == CLASS || site.tag == TYPEVAR)) {
2124 Type s = types.asOuterSuper(site, v.owner);
2125 if (s != null &&
2126 s.isRaw() &&
2127 !types.isSameType(v.type, v.erasure(types))) {
2128 chk.warnUnchecked(tree.pos(),
2129 "unchecked.assign.to.var",
2130 v, s);
2131 }
2132 }
2133 // The computed type of a variable is the type of the
2134 // variable symbol, taken as a member of the site type.
2135 owntype = (sym.owner.kind == TYP &&
2136 sym.name != names._this && sym.name != names._super)
2137 ? types.memberType(site, sym)
2138 : sym.type;
2140 if (env.info.tvars.nonEmpty()) {
2141 Type owntype1 = new ForAll(env.info.tvars, owntype);
2142 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2143 if (!owntype.contains(l.head)) {
2144 log.error(tree.pos(), "undetermined.type", owntype1);
2145 owntype1 = types.createErrorType(owntype1);
2146 }
2147 owntype = owntype1;
2148 }
2150 // If the variable is a constant, record constant value in
2151 // computed type.
2152 if (v.getConstValue() != null && isStaticReference(tree))
2153 owntype = owntype.constType(v.getConstValue());
2155 if (pkind == VAL) {
2156 owntype = capture(owntype); // capture "names as expressions"
2157 }
2158 break;
2159 case MTH: {
2160 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2161 owntype = checkMethod(site, sym, env, app.args,
2162 pt.getParameterTypes(), pt.getTypeArguments(),
2163 env.info.varArgs);
2164 break;
2165 }
2166 case PCK: case ERR:
2167 owntype = sym.type;
2168 break;
2169 default:
2170 throw new AssertionError("unexpected kind: " + sym.kind +
2171 " in tree " + tree);
2172 }
2174 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2175 // (for constructors, the error was given when the constructor was
2176 // resolved)
2177 if (sym.name != names.init &&
2178 (sym.flags() & DEPRECATED) != 0 &&
2179 (env.info.scope.owner.flags() & DEPRECATED) == 0 &&
2180 sym.outermostClass() != env.info.scope.owner.outermostClass())
2181 chk.warnDeprecated(tree.pos(), sym);
2183 if ((sym.flags() & PROPRIETARY) != 0)
2184 log.strictWarning(tree.pos(), "sun.proprietary", sym);
2186 // Test (3): if symbol is a variable, check that its type and
2187 // kind are compatible with the prototype and protokind.
2188 return check(tree, owntype, sym.kind, pkind, pt);
2189 }
2191 /** Check that variable is initialized and evaluate the variable's
2192 * initializer, if not yet done. Also check that variable is not
2193 * referenced before it is defined.
2194 * @param tree The tree making up the variable reference.
2195 * @param env The current environment.
2196 * @param v The variable's symbol.
2197 */
2198 private void checkInit(JCTree tree,
2199 Env<AttrContext> env,
2200 VarSymbol v,
2201 boolean onlyWarning) {
2202 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2203 // tree.pos + " " + v.pos + " " +
2204 // Resolve.isStatic(env));//DEBUG
2206 // A forward reference is diagnosed if the declaration position
2207 // of the variable is greater than the current tree position
2208 // and the tree and variable definition occur in the same class
2209 // definition. Note that writes don't count as references.
2210 // This check applies only to class and instance
2211 // variables. Local variables follow different scope rules,
2212 // and are subject to definite assignment checking.
2213 if ((env.info.enclVar == v || v.pos > tree.pos) &&
2214 v.owner.kind == TYP &&
2215 canOwnInitializer(env.info.scope.owner) &&
2216 v.owner == env.info.scope.owner.enclClass() &&
2217 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2218 (env.tree.getTag() != JCTree.ASSIGN ||
2219 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2220 String suffix = (env.info.enclVar == v) ?
2221 "self.ref" : "forward.ref";
2222 if (!onlyWarning || isStaticEnumField(v)) {
2223 log.error(tree.pos(), "illegal." + suffix);
2224 } else if (useBeforeDeclarationWarning) {
2225 log.warning(tree.pos(), suffix, v);
2226 }
2227 }
2229 v.getConstValue(); // ensure initializer is evaluated
2231 checkEnumInitializer(tree, env, v);
2232 }
2234 /**
2235 * Check for illegal references to static members of enum. In
2236 * an enum type, constructors and initializers may not
2237 * reference its static members unless they are constant.
2238 *
2239 * @param tree The tree making up the variable reference.
2240 * @param env The current environment.
2241 * @param v The variable's symbol.
2242 * @see JLS 3rd Ed. (8.9 Enums)
2243 */
2244 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2245 // JLS 3rd Ed.:
2246 //
2247 // "It is a compile-time error to reference a static field
2248 // of an enum type that is not a compile-time constant
2249 // (15.28) from constructors, instance initializer blocks,
2250 // or instance variable initializer expressions of that
2251 // type. It is a compile-time error for the constructors,
2252 // instance initializer blocks, or instance variable
2253 // initializer expressions of an enum constant e to refer
2254 // to itself or to an enum constant of the same type that
2255 // is declared to the right of e."
2256 if (isStaticEnumField(v)) {
2257 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2259 if (enclClass == null || enclClass.owner == null)
2260 return;
2262 // See if the enclosing class is the enum (or a
2263 // subclass thereof) declaring v. If not, this
2264 // reference is OK.
2265 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2266 return;
2268 // If the reference isn't from an initializer, then
2269 // the reference is OK.
2270 if (!Resolve.isInitializer(env))
2271 return;
2273 log.error(tree.pos(), "illegal.enum.static.ref");
2274 }
2275 }
2277 /** Is the given symbol a static, non-constant field of an Enum?
2278 * Note: enum literals should not be regarded as such
2279 */
2280 private boolean isStaticEnumField(VarSymbol v) {
2281 return Flags.isEnum(v.owner) &&
2282 Flags.isStatic(v) &&
2283 !Flags.isConstant(v) &&
2284 v.name != names._class;
2285 }
2287 /** Can the given symbol be the owner of code which forms part
2288 * if class initialization? This is the case if the symbol is
2289 * a type or field, or if the symbol is the synthetic method.
2290 * owning a block.
2291 */
2292 private boolean canOwnInitializer(Symbol sym) {
2293 return
2294 (sym.kind & (VAR | TYP)) != 0 ||
2295 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2296 }
2298 Warner noteWarner = new Warner();
2300 /**
2301 * Check that method arguments conform to its instantation.
2302 **/
2303 public Type checkMethod(Type site,
2304 Symbol sym,
2305 Env<AttrContext> env,
2306 final List<JCExpression> argtrees,
2307 List<Type> argtypes,
2308 List<Type> typeargtypes,
2309 boolean useVarargs) {
2310 // Test (5): if symbol is an instance method of a raw type, issue
2311 // an unchecked warning if its argument types change under erasure.
2312 if (allowGenerics &&
2313 (sym.flags() & STATIC) == 0 &&
2314 (site.tag == CLASS || site.tag == TYPEVAR)) {
2315 Type s = types.asOuterSuper(site, sym.owner);
2316 if (s != null && s.isRaw() &&
2317 !types.isSameTypes(sym.type.getParameterTypes(),
2318 sym.erasure(types).getParameterTypes())) {
2319 chk.warnUnchecked(env.tree.pos(),
2320 "unchecked.call.mbr.of.raw.type",
2321 sym, s);
2322 }
2323 }
2325 // Compute the identifier's instantiated type.
2326 // For methods, we need to compute the instance type by
2327 // Resolve.instantiate from the symbol's type as well as
2328 // any type arguments and value arguments.
2329 noteWarner.warned = false;
2330 Type owntype = rs.instantiate(env,
2331 site,
2332 sym,
2333 argtypes,
2334 typeargtypes,
2335 true,
2336 useVarargs,
2337 noteWarner);
2338 boolean warned = noteWarner.warned;
2340 // If this fails, something went wrong; we should not have
2341 // found the identifier in the first place.
2342 if (owntype == null) {
2343 if (!pt.isErroneous())
2344 log.error(env.tree.pos(),
2345 "internal.error.cant.instantiate",
2346 sym, site,
2347 Type.toString(pt.getParameterTypes()));
2348 owntype = types.createErrorType(site);
2349 } else {
2350 // System.out.println("call : " + env.tree);
2351 // System.out.println("method : " + owntype);
2352 // System.out.println("actuals: " + argtypes);
2353 List<Type> formals = owntype.getParameterTypes();
2354 Type last = useVarargs ? formals.last() : null;
2355 if (sym.name==names.init &&
2356 sym.owner == syms.enumSym)
2357 formals = formals.tail.tail;
2358 List<JCExpression> args = argtrees;
2359 while (formals.head != last) {
2360 JCTree arg = args.head;
2361 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2362 assertConvertible(arg, arg.type, formals.head, warn);
2363 warned |= warn.warned;
2364 args = args.tail;
2365 formals = formals.tail;
2366 }
2367 if (useVarargs) {
2368 Type varArg = types.elemtype(last);
2369 while (args.tail != null) {
2370 JCTree arg = args.head;
2371 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2372 assertConvertible(arg, arg.type, varArg, warn);
2373 warned |= warn.warned;
2374 args = args.tail;
2375 }
2376 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2377 // non-varargs call to varargs method
2378 Type varParam = owntype.getParameterTypes().last();
2379 Type lastArg = argtypes.last();
2380 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2381 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2382 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2383 types.elemtype(varParam),
2384 varParam);
2385 }
2387 if (warned && sym.type.tag == FORALL) {
2388 chk.warnUnchecked(env.tree.pos(),
2389 "unchecked.meth.invocation.applied",
2390 kindName(sym),
2391 sym.name,
2392 rs.methodArguments(sym.type.getParameterTypes()),
2393 rs.methodArguments(argtypes),
2394 kindName(sym.location()),
2395 sym.location());
2396 owntype = new MethodType(owntype.getParameterTypes(),
2397 types.erasure(owntype.getReturnType()),
2398 owntype.getThrownTypes(),
2399 syms.methodClass);
2400 }
2401 if (useVarargs) {
2402 JCTree tree = env.tree;
2403 Type argtype = owntype.getParameterTypes().last();
2404 if (!types.isReifiable(argtype))
2405 chk.warnUnchecked(env.tree.pos(),
2406 "unchecked.generic.array.creation",
2407 argtype);
2408 Type elemtype = types.elemtype(argtype);
2409 switch (tree.getTag()) {
2410 case JCTree.APPLY:
2411 ((JCMethodInvocation) tree).varargsElement = elemtype;
2412 break;
2413 case JCTree.NEWCLASS:
2414 ((JCNewClass) tree).varargsElement = elemtype;
2415 break;
2416 default:
2417 throw new AssertionError(""+tree);
2418 }
2419 }
2420 }
2421 return owntype;
2422 }
2424 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2425 if (types.isConvertible(actual, formal, warn))
2426 return;
2428 if (formal.isCompound()
2429 && types.isSubtype(actual, types.supertype(formal))
2430 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2431 return;
2433 if (false) {
2434 // TODO: make assertConvertible work
2435 chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal);
2436 throw new AssertionError("Tree: " + tree
2437 + " actual:" + actual
2438 + " formal: " + formal);
2439 }
2440 }
2442 public void visitLiteral(JCLiteral tree) {
2443 result = check(
2444 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2445 }
2446 //where
2447 /** Return the type of a literal with given type tag.
2448 */
2449 Type litType(int tag) {
2450 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2451 }
2453 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2454 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2455 }
2457 public void visitTypeArray(JCArrayTypeTree tree) {
2458 Type etype = attribType(tree.elemtype, env);
2459 Type type = new ArrayType(etype, syms.arrayClass);
2460 result = check(tree, type, TYP, pkind, pt);
2461 }
2463 /** Visitor method for parameterized types.
2464 * Bound checking is left until later, since types are attributed
2465 * before supertype structure is completely known
2466 */
2467 public void visitTypeApply(JCTypeApply tree) {
2468 Type owntype = types.createErrorType(tree.type);
2470 // Attribute functor part of application and make sure it's a class.
2471 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2473 // Attribute type parameters
2474 List<Type> actuals = attribTypes(tree.arguments, env);
2476 if (clazztype.tag == CLASS) {
2477 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2479 if (actuals.length() == formals.length()) {
2480 List<Type> a = actuals;
2481 List<Type> f = formals;
2482 while (a.nonEmpty()) {
2483 a.head = a.head.withTypeVar(f.head);
2484 a = a.tail;
2485 f = f.tail;
2486 }
2487 // Compute the proper generic outer
2488 Type clazzOuter = clazztype.getEnclosingType();
2489 if (clazzOuter.tag == CLASS) {
2490 Type site;
2491 if (tree.clazz.getTag() == JCTree.IDENT) {
2492 site = env.enclClass.sym.type;
2493 } else if (tree.clazz.getTag() == JCTree.SELECT) {
2494 site = ((JCFieldAccess) tree.clazz).selected.type;
2495 } else throw new AssertionError(""+tree);
2496 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2497 if (site.tag == CLASS)
2498 site = types.asOuterSuper(site, clazzOuter.tsym);
2499 if (site == null)
2500 site = types.erasure(clazzOuter);
2501 clazzOuter = site;
2502 }
2503 }
2504 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2505 } else {
2506 if (formals.length() != 0) {
2507 log.error(tree.pos(), "wrong.number.type.args",
2508 Integer.toString(formals.length()));
2509 } else {
2510 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2511 }
2512 owntype = types.createErrorType(tree.type);
2513 }
2514 }
2515 result = check(tree, owntype, TYP, pkind, pt);
2516 }
2518 public void visitTypeParameter(JCTypeParameter tree) {
2519 TypeVar a = (TypeVar)tree.type;
2520 Set<Type> boundSet = new HashSet<Type>();
2521 if (a.bound.isErroneous())
2522 return;
2523 List<Type> bs = types.getBounds(a);
2524 if (tree.bounds.nonEmpty()) {
2525 // accept class or interface or typevar as first bound.
2526 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2527 boundSet.add(types.erasure(b));
2528 if (b.isErroneous()) {
2529 a.bound = b;
2530 }
2531 else if (b.tag == TYPEVAR) {
2532 // if first bound was a typevar, do not accept further bounds.
2533 if (tree.bounds.tail.nonEmpty()) {
2534 log.error(tree.bounds.tail.head.pos(),
2535 "type.var.may.not.be.followed.by.other.bounds");
2536 tree.bounds = List.of(tree.bounds.head);
2537 a.bound = bs.head;
2538 }
2539 } else {
2540 // if first bound was a class or interface, accept only interfaces
2541 // as further bounds.
2542 for (JCExpression bound : tree.bounds.tail) {
2543 bs = bs.tail;
2544 Type i = checkBase(bs.head, bound, env, false, true, false);
2545 if (i.isErroneous())
2546 a.bound = i;
2547 else if (i.tag == CLASS)
2548 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
2549 }
2550 }
2551 }
2552 bs = types.getBounds(a);
2554 // in case of multiple bounds ...
2555 if (bs.length() > 1) {
2556 // ... the variable's bound is a class type flagged COMPOUND
2557 // (see comment for TypeVar.bound).
2558 // In this case, generate a class tree that represents the
2559 // bound class, ...
2560 JCTree extending;
2561 List<JCExpression> implementing;
2562 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
2563 extending = tree.bounds.head;
2564 implementing = tree.bounds.tail;
2565 } else {
2566 extending = null;
2567 implementing = tree.bounds;
2568 }
2569 JCClassDecl cd = make.at(tree.pos).ClassDef(
2570 make.Modifiers(PUBLIC | ABSTRACT),
2571 tree.name, List.<JCTypeParameter>nil(),
2572 extending, implementing, List.<JCTree>nil());
2574 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
2575 assert (c.flags() & COMPOUND) != 0;
2576 cd.sym = c;
2577 c.sourcefile = env.toplevel.sourcefile;
2579 // ... and attribute the bound class
2580 c.flags_field |= UNATTRIBUTED;
2581 Env<AttrContext> cenv = enter.classEnv(cd, env);
2582 enter.typeEnvs.put(c, cenv);
2583 }
2584 }
2587 public void visitWildcard(JCWildcard tree) {
2588 //- System.err.println("visitWildcard("+tree+");");//DEBUG
2589 Type type = (tree.kind.kind == BoundKind.UNBOUND)
2590 ? syms.objectType
2591 : attribType(tree.inner, env);
2592 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
2593 tree.kind.kind,
2594 syms.boundClass),
2595 TYP, pkind, pt);
2596 }
2598 public void visitAnnotation(JCAnnotation tree) {
2599 log.error(tree.pos(), "annotation.not.valid.for.type", pt);
2600 result = tree.type = syms.errType;
2601 }
2603 public void visitErroneous(JCErroneous tree) {
2604 if (tree.errs != null)
2605 for (JCTree err : tree.errs)
2606 attribTree(err, env, ERR, pt);
2607 result = tree.type = syms.errType;
2608 }
2610 /** Default visitor method for all other trees.
2611 */
2612 public void visitTree(JCTree tree) {
2613 throw new AssertionError();
2614 }
2616 /** Main method: attribute class definition associated with given class symbol.
2617 * reporting completion failures at the given position.
2618 * @param pos The source position at which completion errors are to be
2619 * reported.
2620 * @param c The class symbol whose definition will be attributed.
2621 */
2622 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
2623 try {
2624 annotate.flush();
2625 attribClass(c);
2626 } catch (CompletionFailure ex) {
2627 chk.completionError(pos, ex);
2628 }
2629 }
2631 /** Attribute class definition associated with given class symbol.
2632 * @param c The class symbol whose definition will be attributed.
2633 */
2634 void attribClass(ClassSymbol c) throws CompletionFailure {
2635 if (c.type.tag == ERROR) return;
2637 // Check for cycles in the inheritance graph, which can arise from
2638 // ill-formed class files.
2639 chk.checkNonCyclic(null, c.type);
2641 Type st = types.supertype(c.type);
2642 if ((c.flags_field & Flags.COMPOUND) == 0) {
2643 // First, attribute superclass.
2644 if (st.tag == CLASS)
2645 attribClass((ClassSymbol)st.tsym);
2647 // Next attribute owner, if it is a class.
2648 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
2649 attribClass((ClassSymbol)c.owner);
2650 }
2652 // The previous operations might have attributed the current class
2653 // if there was a cycle. So we test first whether the class is still
2654 // UNATTRIBUTED.
2655 if ((c.flags_field & UNATTRIBUTED) != 0) {
2656 c.flags_field &= ~UNATTRIBUTED;
2658 // Get environment current at the point of class definition.
2659 Env<AttrContext> env = enter.typeEnvs.get(c);
2661 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
2662 // because the annotations were not available at the time the env was created. Therefore,
2663 // we look up the environment chain for the first enclosing environment for which the
2664 // lint value is set. Typically, this is the parent env, but might be further if there
2665 // are any envs created as a result of TypeParameter nodes.
2666 Env<AttrContext> lintEnv = env;
2667 while (lintEnv.info.lint == null)
2668 lintEnv = lintEnv.next;
2670 // Having found the enclosing lint value, we can initialize the lint value for this class
2671 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
2673 Lint prevLint = chk.setLint(env.info.lint);
2674 JavaFileObject prev = log.useSource(c.sourcefile);
2676 try {
2677 // java.lang.Enum may not be subclassed by a non-enum
2678 if (st.tsym == syms.enumSym &&
2679 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
2680 log.error(env.tree.pos(), "enum.no.subclassing");
2682 // Enums may not be extended by source-level classes
2683 if (st.tsym != null &&
2684 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
2685 ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
2686 !target.compilerBootstrap(c)) {
2687 log.error(env.tree.pos(), "enum.types.not.extensible");
2688 }
2689 attribClassBody(env, c);
2691 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
2692 } finally {
2693 log.useSource(prev);
2694 chk.setLint(prevLint);
2695 }
2697 }
2698 }
2700 public void visitImport(JCImport tree) {
2701 // nothing to do
2702 }
2704 /** Finish the attribution of a class. */
2705 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
2706 JCClassDecl tree = (JCClassDecl)env.tree;
2707 assert c == tree.sym;
2709 // Validate annotations
2710 chk.validateAnnotations(tree.mods.annotations, c);
2712 // Validate type parameters, supertype and interfaces.
2713 attribBounds(tree.typarams);
2714 chk.validate(tree.typarams, env);
2715 chk.validate(tree.extending, env);
2716 chk.validate(tree.implementing, env);
2718 // If this is a non-abstract class, check that it has no abstract
2719 // methods or unimplemented methods of an implemented interface.
2720 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
2721 if (!relax)
2722 chk.checkAllDefined(tree.pos(), c);
2723 }
2725 if ((c.flags() & ANNOTATION) != 0) {
2726 if (tree.implementing.nonEmpty())
2727 log.error(tree.implementing.head.pos(),
2728 "cant.extend.intf.annotation");
2729 if (tree.typarams.nonEmpty())
2730 log.error(tree.typarams.head.pos(),
2731 "intf.annotation.cant.have.type.params");
2732 } else {
2733 // Check that all extended classes and interfaces
2734 // are compatible (i.e. no two define methods with same arguments
2735 // yet different return types). (JLS 8.4.6.3)
2736 chk.checkCompatibleSupertypes(tree.pos(), c.type);
2737 }
2739 // Check that class does not import the same parameterized interface
2740 // with two different argument lists.
2741 chk.checkClassBounds(tree.pos(), c.type);
2743 tree.type = c.type;
2745 boolean assertsEnabled = false;
2746 assert assertsEnabled = true;
2747 if (assertsEnabled) {
2748 for (List<JCTypeParameter> l = tree.typarams;
2749 l.nonEmpty(); l = l.tail)
2750 assert env.info.scope.lookup(l.head.name).scope != null;
2751 }
2753 // Check that a generic class doesn't extend Throwable
2754 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
2755 log.error(tree.extending.pos(), "generic.throwable");
2757 // Check that all methods which implement some
2758 // method conform to the method they implement.
2759 chk.checkImplementations(tree);
2761 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2762 // Attribute declaration
2763 attribStat(l.head, env);
2764 // Check that declarations in inner classes are not static (JLS 8.1.2)
2765 // Make an exception for static constants.
2766 if (c.owner.kind != PCK &&
2767 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
2768 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
2769 Symbol sym = null;
2770 if (l.head.getTag() == JCTree.VARDEF) sym = ((JCVariableDecl) l.head).sym;
2771 if (sym == null ||
2772 sym.kind != VAR ||
2773 ((VarSymbol) sym).getConstValue() == null)
2774 log.error(l.head.pos(), "icls.cant.have.static.decl");
2775 }
2776 }
2778 // Check for cycles among non-initial constructors.
2779 chk.checkCyclicConstructors(tree);
2781 // Check for cycles among annotation elements.
2782 chk.checkNonCyclicElements(tree);
2784 // Check for proper use of serialVersionUID
2785 if (env.info.lint.isEnabled(Lint.LintCategory.SERIAL) &&
2786 isSerializable(c) &&
2787 (c.flags() & Flags.ENUM) == 0 &&
2788 (c.flags() & ABSTRACT) == 0) {
2789 checkSerialVersionUID(tree, c);
2790 }
2791 }
2792 // where
2793 /** check if a class is a subtype of Serializable, if that is available. */
2794 private boolean isSerializable(ClassSymbol c) {
2795 try {
2796 syms.serializableType.complete();
2797 }
2798 catch (CompletionFailure e) {
2799 return false;
2800 }
2801 return types.isSubtype(c.type, syms.serializableType);
2802 }
2804 /** Check that an appropriate serialVersionUID member is defined. */
2805 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
2807 // check for presence of serialVersionUID
2808 Scope.Entry e = c.members().lookup(names.serialVersionUID);
2809 while (e.scope != null && e.sym.kind != VAR) e = e.next();
2810 if (e.scope == null) {
2811 log.warning(tree.pos(), "missing.SVUID", c);
2812 return;
2813 }
2815 // check that it is static final
2816 VarSymbol svuid = (VarSymbol)e.sym;
2817 if ((svuid.flags() & (STATIC | FINAL)) !=
2818 (STATIC | FINAL))
2819 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
2821 // check that it is long
2822 else if (svuid.type.tag != TypeTags.LONG)
2823 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
2825 // check constant
2826 else if (svuid.getConstValue() == null)
2827 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
2828 }
2830 private Type capture(Type type) {
2831 return types.capture(type);
2832 }
2833 }