Tue, 29 Mar 2011 16:40:51 +0100
7030150: Type inference for generic instance creation failed for formal type parameter
Summary: Problem when explicit generic constructor type-arguments are used in conjunction with diamond
Reviewed-by: jjg
1 /*
2 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
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.Lint.LintCategory;
42 import com.sun.tools.javac.code.Symbol.*;
43 import com.sun.tools.javac.tree.JCTree.*;
44 import com.sun.tools.javac.code.Type.*;
46 import com.sun.source.tree.IdentifierTree;
47 import com.sun.source.tree.MemberSelectTree;
48 import com.sun.source.tree.TreeVisitor;
49 import com.sun.source.util.SimpleTreeVisitor;
51 import static com.sun.tools.javac.code.Flags.*;
52 import static com.sun.tools.javac.code.Kinds.*;
53 import static com.sun.tools.javac.code.TypeTags.*;
55 /** This is the main context-dependent analysis phase in GJC. It
56 * encompasses name resolution, type checking and constant folding as
57 * subtasks. Some subtasks involve auxiliary classes.
58 * @see Check
59 * @see Resolve
60 * @see ConstFold
61 * @see Infer
62 *
63 * <p><b>This is NOT part of any supported API.
64 * If you write code that depends on this, you do so at your own risk.
65 * This code and its internal interfaces are subject to change or
66 * deletion without notice.</b>
67 */
68 public class Attr extends JCTree.Visitor {
69 protected static final Context.Key<Attr> attrKey =
70 new Context.Key<Attr>();
72 final Names names;
73 final Log log;
74 final Symtab syms;
75 final Resolve rs;
76 final Infer infer;
77 final Check chk;
78 final MemberEnter memberEnter;
79 final TreeMaker make;
80 final ConstFold cfolder;
81 final Enter enter;
82 final Target target;
83 final Types types;
84 final JCDiagnostic.Factory diags;
85 final Annotate annotate;
86 final DeferredLintHandler deferredLintHandler;
88 public static Attr instance(Context context) {
89 Attr instance = context.get(attrKey);
90 if (instance == null)
91 instance = new Attr(context);
92 return instance;
93 }
95 protected Attr(Context context) {
96 context.put(attrKey, this);
98 names = Names.instance(context);
99 log = Log.instance(context);
100 syms = Symtab.instance(context);
101 rs = Resolve.instance(context);
102 chk = Check.instance(context);
103 memberEnter = MemberEnter.instance(context);
104 make = TreeMaker.instance(context);
105 enter = Enter.instance(context);
106 infer = Infer.instance(context);
107 cfolder = ConstFold.instance(context);
108 target = Target.instance(context);
109 types = Types.instance(context);
110 diags = JCDiagnostic.Factory.instance(context);
111 annotate = Annotate.instance(context);
112 deferredLintHandler = DeferredLintHandler.instance(context);
114 Options options = Options.instance(context);
116 Source source = Source.instance(context);
117 allowGenerics = source.allowGenerics();
118 allowVarargs = source.allowVarargs();
119 allowEnums = source.allowEnums();
120 allowBoxing = source.allowBoxing();
121 allowCovariantReturns = source.allowCovariantReturns();
122 allowAnonOuterThis = source.allowAnonOuterThis();
123 allowStringsInSwitch = source.allowStringsInSwitch();
124 sourceName = source.name;
125 relax = (options.isSet("-retrofit") ||
126 options.isSet("-relax"));
127 findDiamonds = options.get("findDiamond") != null &&
128 source.allowDiamond();
129 useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
130 }
132 /** Switch: relax some constraints for retrofit mode.
133 */
134 boolean relax;
136 /** Switch: support generics?
137 */
138 boolean allowGenerics;
140 /** Switch: allow variable-arity methods.
141 */
142 boolean allowVarargs;
144 /** Switch: support enums?
145 */
146 boolean allowEnums;
148 /** Switch: support boxing and unboxing?
149 */
150 boolean allowBoxing;
152 /** Switch: support covariant result types?
153 */
154 boolean allowCovariantReturns;
156 /** Switch: allow references to surrounding object from anonymous
157 * objects during constructor call?
158 */
159 boolean allowAnonOuterThis;
161 /** Switch: generates a warning if diamond can be safely applied
162 * to a given new expression
163 */
164 boolean findDiamonds;
166 /**
167 * Internally enables/disables diamond finder feature
168 */
169 static final boolean allowDiamondFinder = true;
171 /**
172 * Switch: warn about use of variable before declaration?
173 * RFE: 6425594
174 */
175 boolean useBeforeDeclarationWarning;
177 /**
178 * Switch: allow strings in switch?
179 */
180 boolean allowStringsInSwitch;
182 /**
183 * Switch: name of source level; used for error reporting.
184 */
185 String sourceName;
187 /** Check kind and type of given tree against protokind and prototype.
188 * If check succeeds, store type in tree and return it.
189 * If check fails, store errType in tree and return it.
190 * No checks are performed if the prototype is a method type.
191 * It is not necessary in this case since we know that kind and type
192 * are correct.
193 *
194 * @param tree The tree whose kind and type is checked
195 * @param owntype The computed type of the tree
196 * @param ownkind The computed kind of the tree
197 * @param pkind The expected kind (or: protokind) of the tree
198 * @param pt The expected type (or: prototype) of the tree
199 */
200 Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
201 if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
202 if ((ownkind & ~pkind) == 0) {
203 owntype = chk.checkType(tree.pos(), owntype, pt, errKey);
204 } else {
205 log.error(tree.pos(), "unexpected.type",
206 kindNames(pkind),
207 kindName(ownkind));
208 owntype = types.createErrorType(owntype);
209 }
210 }
211 tree.type = owntype;
212 return owntype;
213 }
215 /** Is given blank final variable assignable, i.e. in a scope where it
216 * may be assigned to even though it is final?
217 * @param v The blank final variable.
218 * @param env The current environment.
219 */
220 boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
221 Symbol owner = env.info.scope.owner;
222 // owner refers to the innermost variable, method or
223 // initializer block declaration at this point.
224 return
225 v.owner == owner
226 ||
227 ((owner.name == names.init || // i.e. we are in a constructor
228 owner.kind == VAR || // i.e. we are in a variable initializer
229 (owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
230 &&
231 v.owner == owner.owner
232 &&
233 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
234 }
236 /** Check that variable can be assigned to.
237 * @param pos The current source code position.
238 * @param v The assigned varaible
239 * @param base If the variable is referred to in a Select, the part
240 * to the left of the `.', null otherwise.
241 * @param env The current environment.
242 */
243 void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
244 if ((v.flags() & FINAL) != 0 &&
245 ((v.flags() & HASINIT) != 0
246 ||
247 !((base == null ||
248 (base.getTag() == JCTree.IDENT && TreeInfo.name(base) == names._this)) &&
249 isAssignableAsBlankFinal(v, env)))) {
250 if (v.isResourceVariable()) { //TWR resource
251 log.error(pos, "try.resource.may.not.be.assigned", v);
252 } else {
253 log.error(pos, "cant.assign.val.to.final.var", v);
254 }
255 } else if ((v.flags() & EFFECTIVELY_FINAL) != 0) {
256 v.flags_field &= ~EFFECTIVELY_FINAL;
257 }
258 }
260 /** Does tree represent a static reference to an identifier?
261 * It is assumed that tree is either a SELECT or an IDENT.
262 * We have to weed out selects from non-type names here.
263 * @param tree The candidate tree.
264 */
265 boolean isStaticReference(JCTree tree) {
266 if (tree.getTag() == JCTree.SELECT) {
267 Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
268 if (lsym == null || lsym.kind != TYP) {
269 return false;
270 }
271 }
272 return true;
273 }
275 /** Is this symbol a type?
276 */
277 static boolean isType(Symbol sym) {
278 return sym != null && sym.kind == TYP;
279 }
281 /** The current `this' symbol.
282 * @param env The current environment.
283 */
284 Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
285 return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
286 }
288 /** Attribute a parsed identifier.
289 * @param tree Parsed identifier name
290 * @param topLevel The toplevel to use
291 */
292 public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
293 Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
294 localEnv.enclClass = make.ClassDef(make.Modifiers(0),
295 syms.errSymbol.name,
296 null, null, null, null);
297 localEnv.enclClass.sym = syms.errSymbol;
298 return tree.accept(identAttributer, localEnv);
299 }
300 // where
301 private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
302 private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
303 @Override
304 public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
305 Symbol site = visit(node.getExpression(), env);
306 if (site.kind == ERR)
307 return site;
308 Name name = (Name)node.getIdentifier();
309 if (site.kind == PCK) {
310 env.toplevel.packge = (PackageSymbol)site;
311 return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
312 } else {
313 env.enclClass.sym = (ClassSymbol)site;
314 return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
315 }
316 }
318 @Override
319 public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
320 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
321 }
322 }
324 public Type coerce(Type etype, Type ttype) {
325 return cfolder.coerce(etype, ttype);
326 }
328 public Type attribType(JCTree node, TypeSymbol sym) {
329 Env<AttrContext> env = enter.typeEnvs.get(sym);
330 Env<AttrContext> localEnv = env.dup(node, env.info.dup());
331 return attribTree(node, localEnv, Kinds.TYP, Type.noType);
332 }
334 public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
335 breakTree = tree;
336 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
337 try {
338 attribExpr(expr, env);
339 } catch (BreakAttr b) {
340 return b.env;
341 } catch (AssertionError ae) {
342 if (ae.getCause() instanceof BreakAttr) {
343 return ((BreakAttr)(ae.getCause())).env;
344 } else {
345 throw ae;
346 }
347 } finally {
348 breakTree = null;
349 log.useSource(prev);
350 }
351 return env;
352 }
354 public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
355 breakTree = tree;
356 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
357 try {
358 attribStat(stmt, env);
359 } catch (BreakAttr b) {
360 return b.env;
361 } catch (AssertionError ae) {
362 if (ae.getCause() instanceof BreakAttr) {
363 return ((BreakAttr)(ae.getCause())).env;
364 } else {
365 throw ae;
366 }
367 } finally {
368 breakTree = null;
369 log.useSource(prev);
370 }
371 return env;
372 }
374 private JCTree breakTree = null;
376 private static class BreakAttr extends RuntimeException {
377 static final long serialVersionUID = -6924771130405446405L;
378 private Env<AttrContext> env;
379 private BreakAttr(Env<AttrContext> env) {
380 this.env = env;
381 }
382 }
385 /* ************************************************************************
386 * Visitor methods
387 *************************************************************************/
389 /** Visitor argument: the current environment.
390 */
391 Env<AttrContext> env;
393 /** Visitor argument: the currently expected proto-kind.
394 */
395 int pkind;
397 /** Visitor argument: the currently expected proto-type.
398 */
399 Type pt;
401 /** Visitor argument: the error key to be generated when a type error occurs
402 */
403 String errKey;
405 /** Visitor result: the computed type.
406 */
407 Type result;
409 /** Visitor method: attribute a tree, catching any completion failure
410 * exceptions. Return the tree's type.
411 *
412 * @param tree The tree to be visited.
413 * @param env The environment visitor argument.
414 * @param pkind The protokind visitor argument.
415 * @param pt The prototype visitor argument.
416 */
417 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) {
418 return attribTree(tree, env, pkind, pt, "incompatible.types");
419 }
421 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt, String errKey) {
422 Env<AttrContext> prevEnv = this.env;
423 int prevPkind = this.pkind;
424 Type prevPt = this.pt;
425 String prevErrKey = this.errKey;
426 try {
427 this.env = env;
428 this.pkind = pkind;
429 this.pt = pt;
430 this.errKey = errKey;
431 tree.accept(this);
432 if (tree == breakTree)
433 throw new BreakAttr(env);
434 return result;
435 } catch (CompletionFailure ex) {
436 tree.type = syms.errType;
437 return chk.completionError(tree.pos(), ex);
438 } finally {
439 this.env = prevEnv;
440 this.pkind = prevPkind;
441 this.pt = prevPt;
442 this.errKey = prevErrKey;
443 }
444 }
446 /** Derived visitor method: attribute an expression tree.
447 */
448 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
449 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
450 }
452 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt, String key) {
453 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType, key);
454 }
456 /** Derived visitor method: attribute an expression tree with
457 * no constraints on the computed type.
458 */
459 Type attribExpr(JCTree tree, Env<AttrContext> env) {
460 return attribTree(tree, env, VAL, Type.noType);
461 }
463 /** Derived visitor method: attribute a type tree.
464 */
465 Type attribType(JCTree tree, Env<AttrContext> env) {
466 Type result = attribType(tree, env, Type.noType);
467 return result;
468 }
470 /** Derived visitor method: attribute a type tree.
471 */
472 Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
473 Type result = attribTree(tree, env, TYP, pt);
474 return result;
475 }
477 /** Derived visitor method: attribute a statement or definition tree.
478 */
479 public Type attribStat(JCTree tree, Env<AttrContext> env) {
480 return attribTree(tree, env, NIL, Type.noType);
481 }
483 /** Attribute a list of expressions, returning a list of types.
484 */
485 List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
486 ListBuffer<Type> ts = new ListBuffer<Type>();
487 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
488 ts.append(attribExpr(l.head, env, pt));
489 return ts.toList();
490 }
492 /** Attribute a list of statements, returning nothing.
493 */
494 <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
495 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
496 attribStat(l.head, env);
497 }
499 /** Attribute the arguments in a method call, returning a list of types.
500 */
501 List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
502 ListBuffer<Type> argtypes = new ListBuffer<Type>();
503 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
504 argtypes.append(chk.checkNonVoid(
505 l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly))));
506 return argtypes.toList();
507 }
509 /** Attribute a type argument list, returning a list of types.
510 * Caller is responsible for calling checkRefTypes.
511 */
512 List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
513 ListBuffer<Type> argtypes = new ListBuffer<Type>();
514 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
515 argtypes.append(attribType(l.head, env));
516 return argtypes.toList();
517 }
519 /** Attribute a type argument list, returning a list of types.
520 * Check that all the types are references.
521 */
522 List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
523 List<Type> types = attribAnyTypes(trees, env);
524 return chk.checkRefTypes(trees, types);
525 }
527 /**
528 * Attribute type variables (of generic classes or methods).
529 * Compound types are attributed later in attribBounds.
530 * @param typarams the type variables to enter
531 * @param env the current environment
532 */
533 void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
534 for (JCTypeParameter tvar : typarams) {
535 TypeVar a = (TypeVar)tvar.type;
536 a.tsym.flags_field |= UNATTRIBUTED;
537 a.bound = Type.noType;
538 if (!tvar.bounds.isEmpty()) {
539 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
540 for (JCExpression bound : tvar.bounds.tail)
541 bounds = bounds.prepend(attribType(bound, env));
542 types.setBounds(a, bounds.reverse());
543 } else {
544 // if no bounds are given, assume a single bound of
545 // java.lang.Object.
546 types.setBounds(a, List.of(syms.objectType));
547 }
548 a.tsym.flags_field &= ~UNATTRIBUTED;
549 }
550 for (JCTypeParameter tvar : typarams)
551 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
552 attribStats(typarams, env);
553 }
555 void attribBounds(List<JCTypeParameter> typarams) {
556 for (JCTypeParameter typaram : typarams) {
557 Type bound = typaram.type.getUpperBound();
558 if (bound != null && bound.tsym instanceof ClassSymbol) {
559 ClassSymbol c = (ClassSymbol)bound.tsym;
560 if ((c.flags_field & COMPOUND) != 0) {
561 Assert.check((c.flags_field & UNATTRIBUTED) != 0, c);
562 attribClass(typaram.pos(), c);
563 }
564 }
565 }
566 }
568 /**
569 * Attribute the type references in a list of annotations.
570 */
571 void attribAnnotationTypes(List<JCAnnotation> annotations,
572 Env<AttrContext> env) {
573 for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
574 JCAnnotation a = al.head;
575 attribType(a.annotationType, env);
576 }
577 }
579 /**
580 * Attribute a "lazy constant value".
581 * @param env The env for the const value
582 * @param initializer The initializer for the const value
583 * @param type The expected type, or null
584 * @see VarSymbol#setlazyConstValue
585 */
586 public Object attribLazyConstantValue(Env<AttrContext> env,
587 JCTree.JCExpression initializer,
588 Type type) {
590 // in case no lint value has been set up for this env, scan up
591 // env stack looking for smallest enclosing env for which it is set.
592 Env<AttrContext> lintEnv = env;
593 while (lintEnv.info.lint == null)
594 lintEnv = lintEnv.next;
596 // Having found the enclosing lint value, we can initialize the lint value for this class
597 env.info.lint = lintEnv.info.lint.augment(env.info.enclVar.attributes_field, env.info.enclVar.flags());
599 Lint prevLint = chk.setLint(env.info.lint);
600 JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
602 try {
603 Type itype = attribExpr(initializer, env, type);
604 if (itype.constValue() != null)
605 return coerce(itype, type).constValue();
606 else
607 return null;
608 } finally {
609 env.info.lint = prevLint;
610 log.useSource(prevSource);
611 }
612 }
614 /** Attribute type reference in an `extends' or `implements' clause.
615 * Supertypes of anonymous inner classes are usually already attributed.
616 *
617 * @param tree The tree making up the type reference.
618 * @param env The environment current at the reference.
619 * @param classExpected true if only a class is expected here.
620 * @param interfaceExpected true if only an interface is expected here.
621 */
622 Type attribBase(JCTree tree,
623 Env<AttrContext> env,
624 boolean classExpected,
625 boolean interfaceExpected,
626 boolean checkExtensible) {
627 Type t = tree.type != null ?
628 tree.type :
629 attribType(tree, env);
630 return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
631 }
632 Type checkBase(Type t,
633 JCTree tree,
634 Env<AttrContext> env,
635 boolean classExpected,
636 boolean interfaceExpected,
637 boolean checkExtensible) {
638 if (t.isErroneous())
639 return t;
640 if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
641 // check that type variable is already visible
642 if (t.getUpperBound() == null) {
643 log.error(tree.pos(), "illegal.forward.ref");
644 return types.createErrorType(t);
645 }
646 } else {
647 t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
648 }
649 if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
650 log.error(tree.pos(), "intf.expected.here");
651 // return errType is necessary since otherwise there might
652 // be undetected cycles which cause attribution to loop
653 return types.createErrorType(t);
654 } else if (checkExtensible &&
655 classExpected &&
656 (t.tsym.flags() & INTERFACE) != 0) {
657 log.error(tree.pos(), "no.intf.expected.here");
658 return types.createErrorType(t);
659 }
660 if (checkExtensible &&
661 ((t.tsym.flags() & FINAL) != 0)) {
662 log.error(tree.pos(),
663 "cant.inherit.from.final", t.tsym);
664 }
665 chk.checkNonCyclic(tree.pos(), t);
666 return t;
667 }
669 public void visitClassDef(JCClassDecl tree) {
670 // Local classes have not been entered yet, so we need to do it now:
671 if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
672 enter.classEnter(tree, env);
674 ClassSymbol c = tree.sym;
675 if (c == null) {
676 // exit in case something drastic went wrong during enter.
677 result = null;
678 } else {
679 // make sure class has been completed:
680 c.complete();
682 // If this class appears as an anonymous class
683 // in a superclass constructor call where
684 // no explicit outer instance is given,
685 // disable implicit outer instance from being passed.
686 // (This would be an illegal access to "this before super").
687 if (env.info.isSelfCall &&
688 env.tree.getTag() == JCTree.NEWCLASS &&
689 ((JCNewClass) env.tree).encl == null)
690 {
691 c.flags_field |= NOOUTERTHIS;
692 }
693 attribClass(tree.pos(), c);
694 result = tree.type = c.type;
695 }
696 }
698 public void visitMethodDef(JCMethodDecl tree) {
699 MethodSymbol m = tree.sym;
701 Lint lint = env.info.lint.augment(m.attributes_field, m.flags());
702 Lint prevLint = chk.setLint(lint);
703 MethodSymbol prevMethod = chk.setMethod(m);
704 try {
705 deferredLintHandler.flush(tree.pos());
706 chk.checkDeprecatedAnnotation(tree.pos(), m);
708 attribBounds(tree.typarams);
710 // If we override any other methods, check that we do so properly.
711 // JLS ???
712 if (m.isStatic()) {
713 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
714 } else {
715 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
716 }
717 chk.checkOverride(tree, m);
719 // Create a new environment with local scope
720 // for attributing the method.
721 Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
723 localEnv.info.lint = lint;
725 // Enter all type parameters into the local method scope.
726 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
727 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
729 ClassSymbol owner = env.enclClass.sym;
730 if ((owner.flags() & ANNOTATION) != 0 &&
731 tree.params.nonEmpty())
732 log.error(tree.params.head.pos(),
733 "intf.annotation.members.cant.have.params");
735 // Attribute all value parameters.
736 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
737 attribStat(l.head, localEnv);
738 }
740 chk.checkVarargsMethodDecl(localEnv, tree);
742 // Check that type parameters are well-formed.
743 chk.validate(tree.typarams, localEnv);
745 // Check that result type is well-formed.
746 chk.validate(tree.restype, localEnv);
748 // annotation method checks
749 if ((owner.flags() & ANNOTATION) != 0) {
750 // annotation method cannot have throws clause
751 if (tree.thrown.nonEmpty()) {
752 log.error(tree.thrown.head.pos(),
753 "throws.not.allowed.in.intf.annotation");
754 }
755 // annotation method cannot declare type-parameters
756 if (tree.typarams.nonEmpty()) {
757 log.error(tree.typarams.head.pos(),
758 "intf.annotation.members.cant.have.type.params");
759 }
760 // validate annotation method's return type (could be an annotation type)
761 chk.validateAnnotationType(tree.restype);
762 // ensure that annotation method does not clash with members of Object/Annotation
763 chk.validateAnnotationMethod(tree.pos(), m);
765 if (tree.defaultValue != null) {
766 // if default value is an annotation, check it is a well-formed
767 // annotation value (e.g. no duplicate values, no missing values, etc.)
768 chk.validateAnnotationTree(tree.defaultValue);
769 }
770 }
772 for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
773 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
775 if (tree.body == null) {
776 // Empty bodies are only allowed for
777 // abstract, native, or interface methods, or for methods
778 // in a retrofit signature class.
779 if ((owner.flags() & INTERFACE) == 0 &&
780 (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 &&
781 !relax)
782 log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
783 if (tree.defaultValue != null) {
784 if ((owner.flags() & ANNOTATION) == 0)
785 log.error(tree.pos(),
786 "default.allowed.in.intf.annotation.member");
787 }
788 } else if ((owner.flags() & INTERFACE) != 0) {
789 log.error(tree.body.pos(), "intf.meth.cant.have.body");
790 } else if ((tree.mods.flags & ABSTRACT) != 0) {
791 log.error(tree.pos(), "abstract.meth.cant.have.body");
792 } else if ((tree.mods.flags & NATIVE) != 0) {
793 log.error(tree.pos(), "native.meth.cant.have.body");
794 } else {
795 // Add an implicit super() call unless an explicit call to
796 // super(...) or this(...) is given
797 // or we are compiling class java.lang.Object.
798 if (tree.name == names.init && owner.type != syms.objectType) {
799 JCBlock body = tree.body;
800 if (body.stats.isEmpty() ||
801 !TreeInfo.isSelfCall(body.stats.head)) {
802 body.stats = body.stats.
803 prepend(memberEnter.SuperCall(make.at(body.pos),
804 List.<Type>nil(),
805 List.<JCVariableDecl>nil(),
806 false));
807 } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
808 (tree.mods.flags & GENERATEDCONSTR) == 0 &&
809 TreeInfo.isSuperCall(body.stats.head)) {
810 // enum constructors are not allowed to call super
811 // directly, so make sure there aren't any super calls
812 // in enum constructors, except in the compiler
813 // generated one.
814 log.error(tree.body.stats.head.pos(),
815 "call.to.super.not.allowed.in.enum.ctor",
816 env.enclClass.sym);
817 }
818 }
820 // Attribute method body.
821 attribStat(tree.body, localEnv);
822 }
823 localEnv.info.scope.leave();
824 result = tree.type = m.type;
825 chk.validateAnnotations(tree.mods.annotations, m);
826 }
827 finally {
828 chk.setLint(prevLint);
829 chk.setMethod(prevMethod);
830 }
831 }
833 public void visitVarDef(JCVariableDecl tree) {
834 // Local variables have not been entered yet, so we need to do it now:
835 if (env.info.scope.owner.kind == MTH) {
836 if (tree.sym != null) {
837 // parameters have already been entered
838 env.info.scope.enter(tree.sym);
839 } else {
840 memberEnter.memberEnter(tree, env);
841 annotate.flush();
842 }
843 tree.sym.flags_field |= EFFECTIVELY_FINAL;
844 }
846 VarSymbol v = tree.sym;
847 Lint lint = env.info.lint.augment(v.attributes_field, v.flags());
848 Lint prevLint = chk.setLint(lint);
850 // Check that the variable's declared type is well-formed.
851 chk.validate(tree.vartype, env);
852 deferredLintHandler.flush(tree.pos());
854 try {
855 chk.checkDeprecatedAnnotation(tree.pos(), v);
857 if (tree.init != null) {
858 if ((v.flags_field & FINAL) != 0 && tree.init.getTag() != JCTree.NEWCLASS) {
859 // In this case, `v' is final. Ensure that it's initializer is
860 // evaluated.
861 v.getConstValue(); // ensure initializer is evaluated
862 } else {
863 // Attribute initializer in a new environment
864 // with the declared variable as owner.
865 // Check that initializer conforms to variable's declared type.
866 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
867 initEnv.info.lint = lint;
868 // In order to catch self-references, we set the variable's
869 // declaration position to maximal possible value, effectively
870 // marking the variable as undefined.
871 initEnv.info.enclVar = v;
872 attribExpr(tree.init, initEnv, v.type);
873 }
874 }
875 result = tree.type = v.type;
876 chk.validateAnnotations(tree.mods.annotations, v);
877 }
878 finally {
879 chk.setLint(prevLint);
880 }
881 }
883 public void visitSkip(JCSkip tree) {
884 result = null;
885 }
887 public void visitBlock(JCBlock tree) {
888 if (env.info.scope.owner.kind == TYP) {
889 // Block is a static or instance initializer;
890 // let the owner of the environment be a freshly
891 // created BLOCK-method.
892 Env<AttrContext> localEnv =
893 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
894 localEnv.info.scope.owner =
895 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
896 env.info.scope.owner);
897 if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
898 attribStats(tree.stats, localEnv);
899 } else {
900 // Create a new local environment with a local scope.
901 Env<AttrContext> localEnv =
902 env.dup(tree, env.info.dup(env.info.scope.dup()));
903 attribStats(tree.stats, localEnv);
904 localEnv.info.scope.leave();
905 }
906 result = null;
907 }
909 public void visitDoLoop(JCDoWhileLoop tree) {
910 attribStat(tree.body, env.dup(tree));
911 attribExpr(tree.cond, env, syms.booleanType);
912 result = null;
913 }
915 public void visitWhileLoop(JCWhileLoop tree) {
916 attribExpr(tree.cond, env, syms.booleanType);
917 attribStat(tree.body, env.dup(tree));
918 result = null;
919 }
921 public void visitForLoop(JCForLoop tree) {
922 Env<AttrContext> loopEnv =
923 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
924 attribStats(tree.init, loopEnv);
925 if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
926 loopEnv.tree = tree; // before, we were not in loop!
927 attribStats(tree.step, loopEnv);
928 attribStat(tree.body, loopEnv);
929 loopEnv.info.scope.leave();
930 result = null;
931 }
933 public void visitForeachLoop(JCEnhancedForLoop tree) {
934 Env<AttrContext> loopEnv =
935 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
936 attribStat(tree.var, loopEnv);
937 Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
938 chk.checkNonVoid(tree.pos(), exprType);
939 Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
940 if (elemtype == null) {
941 // or perhaps expr implements Iterable<T>?
942 Type base = types.asSuper(exprType, syms.iterableType.tsym);
943 if (base == null) {
944 log.error(tree.expr.pos(),
945 "foreach.not.applicable.to.type",
946 exprType,
947 diags.fragment("type.req.array.or.iterable"));
948 elemtype = types.createErrorType(exprType);
949 } else {
950 List<Type> iterableParams = base.allparams();
951 elemtype = iterableParams.isEmpty()
952 ? syms.objectType
953 : types.upperBound(iterableParams.head);
954 }
955 }
956 chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
957 loopEnv.tree = tree; // before, we were not in loop!
958 attribStat(tree.body, loopEnv);
959 loopEnv.info.scope.leave();
960 result = null;
961 }
963 public void visitLabelled(JCLabeledStatement tree) {
964 // Check that label is not used in an enclosing statement
965 Env<AttrContext> env1 = env;
966 while (env1 != null && env1.tree.getTag() != JCTree.CLASSDEF) {
967 if (env1.tree.getTag() == JCTree.LABELLED &&
968 ((JCLabeledStatement) env1.tree).label == tree.label) {
969 log.error(tree.pos(), "label.already.in.use",
970 tree.label);
971 break;
972 }
973 env1 = env1.next;
974 }
976 attribStat(tree.body, env.dup(tree));
977 result = null;
978 }
980 public void visitSwitch(JCSwitch tree) {
981 Type seltype = attribExpr(tree.selector, env);
983 Env<AttrContext> switchEnv =
984 env.dup(tree, env.info.dup(env.info.scope.dup()));
986 boolean enumSwitch =
987 allowEnums &&
988 (seltype.tsym.flags() & Flags.ENUM) != 0;
989 boolean stringSwitch = false;
990 if (types.isSameType(seltype, syms.stringType)) {
991 if (allowStringsInSwitch) {
992 stringSwitch = true;
993 } else {
994 log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName);
995 }
996 }
997 if (!enumSwitch && !stringSwitch)
998 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
1000 // Attribute all cases and
1001 // check that there are no duplicate case labels or default clauses.
1002 Set<Object> labels = new HashSet<Object>(); // The set of case labels.
1003 boolean hasDefault = false; // Is there a default label?
1004 for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
1005 JCCase c = l.head;
1006 Env<AttrContext> caseEnv =
1007 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
1008 if (c.pat != null) {
1009 if (enumSwitch) {
1010 Symbol sym = enumConstant(c.pat, seltype);
1011 if (sym == null) {
1012 log.error(c.pat.pos(), "enum.label.must.be.unqualified.enum");
1013 } else if (!labels.add(sym)) {
1014 log.error(c.pos(), "duplicate.case.label");
1015 }
1016 } else {
1017 Type pattype = attribExpr(c.pat, switchEnv, seltype);
1018 if (pattype.tag != ERROR) {
1019 if (pattype.constValue() == null) {
1020 log.error(c.pat.pos(),
1021 (stringSwitch ? "string.const.req" : "const.expr.req"));
1022 } else if (labels.contains(pattype.constValue())) {
1023 log.error(c.pos(), "duplicate.case.label");
1024 } else {
1025 labels.add(pattype.constValue());
1026 }
1027 }
1028 }
1029 } else if (hasDefault) {
1030 log.error(c.pos(), "duplicate.default.label");
1031 } else {
1032 hasDefault = true;
1033 }
1034 attribStats(c.stats, caseEnv);
1035 caseEnv.info.scope.leave();
1036 addVars(c.stats, switchEnv.info.scope);
1037 }
1039 switchEnv.info.scope.leave();
1040 result = null;
1041 }
1042 // where
1043 /** Add any variables defined in stats to the switch scope. */
1044 private static void addVars(List<JCStatement> stats, Scope switchScope) {
1045 for (;stats.nonEmpty(); stats = stats.tail) {
1046 JCTree stat = stats.head;
1047 if (stat.getTag() == JCTree.VARDEF)
1048 switchScope.enter(((JCVariableDecl) stat).sym);
1049 }
1050 }
1051 // where
1052 /** Return the selected enumeration constant symbol, or null. */
1053 private Symbol enumConstant(JCTree tree, Type enumType) {
1054 if (tree.getTag() != JCTree.IDENT) {
1055 log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
1056 return syms.errSymbol;
1057 }
1058 JCIdent ident = (JCIdent)tree;
1059 Name name = ident.name;
1060 for (Scope.Entry e = enumType.tsym.members().lookup(name);
1061 e.scope != null; e = e.next()) {
1062 if (e.sym.kind == VAR) {
1063 Symbol s = ident.sym = e.sym;
1064 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1065 ident.type = s.type;
1066 return ((s.flags_field & Flags.ENUM) == 0)
1067 ? null : s;
1068 }
1069 }
1070 return null;
1071 }
1073 public void visitSynchronized(JCSynchronized tree) {
1074 chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
1075 attribStat(tree.body, env);
1076 result = null;
1077 }
1079 public void visitTry(JCTry tree) {
1080 // Create a new local environment with a local
1081 Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1082 boolean isTryWithResource = tree.resources.nonEmpty();
1083 // Create a nested environment for attributing the try block if needed
1084 Env<AttrContext> tryEnv = isTryWithResource ?
1085 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1086 localEnv;
1087 // Attribute resource declarations
1088 for (JCTree resource : tree.resources) {
1089 if (resource.getTag() == JCTree.VARDEF) {
1090 attribStat(resource, tryEnv);
1091 chk.checkType(resource, resource.type, syms.autoCloseableType, "try.not.applicable.to.type");
1092 VarSymbol var = (VarSymbol)TreeInfo.symbolFor(resource);
1093 var.setData(ElementKind.RESOURCE_VARIABLE);
1094 } else {
1095 attribExpr(resource, tryEnv, syms.autoCloseableType, "try.not.applicable.to.type");
1096 }
1097 }
1098 // Attribute body
1099 attribStat(tree.body, tryEnv);
1100 if (isTryWithResource)
1101 tryEnv.info.scope.leave();
1103 // Attribute catch clauses
1104 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
1105 JCCatch c = l.head;
1106 Env<AttrContext> catchEnv =
1107 localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
1108 Type ctype = attribStat(c.param, catchEnv);
1109 if (TreeInfo.isMultiCatch(c)) {
1110 //multi-catch parameter is implicitly marked as final
1111 c.param.sym.flags_field |= FINAL | DISJUNCTION;
1112 }
1113 if (c.param.sym.kind == Kinds.VAR) {
1114 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
1115 }
1116 chk.checkType(c.param.vartype.pos(),
1117 chk.checkClassType(c.param.vartype.pos(), ctype),
1118 syms.throwableType);
1119 attribStat(c.body, catchEnv);
1120 catchEnv.info.scope.leave();
1121 }
1123 // Attribute finalizer
1124 if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
1126 localEnv.info.scope.leave();
1127 result = null;
1128 }
1130 public void visitConditional(JCConditional tree) {
1131 attribExpr(tree.cond, env, syms.booleanType);
1132 attribExpr(tree.truepart, env);
1133 attribExpr(tree.falsepart, env);
1134 result = check(tree,
1135 capture(condType(tree.pos(), tree.cond.type,
1136 tree.truepart.type, tree.falsepart.type)),
1137 VAL, pkind, pt);
1138 }
1139 //where
1140 /** Compute the type of a conditional expression, after
1141 * checking that it exists. See Spec 15.25.
1142 *
1143 * @param pos The source position to be used for
1144 * error diagnostics.
1145 * @param condtype The type of the expression's condition.
1146 * @param thentype The type of the expression's then-part.
1147 * @param elsetype The type of the expression's else-part.
1148 */
1149 private Type condType(DiagnosticPosition pos,
1150 Type condtype,
1151 Type thentype,
1152 Type elsetype) {
1153 Type ctype = condType1(pos, condtype, thentype, elsetype);
1155 // If condition and both arms are numeric constants,
1156 // evaluate at compile-time.
1157 return ((condtype.constValue() != null) &&
1158 (thentype.constValue() != null) &&
1159 (elsetype.constValue() != null))
1160 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
1161 : ctype;
1162 }
1163 /** Compute the type of a conditional expression, after
1164 * checking that it exists. Does not take into
1165 * account the special case where condition and both arms
1166 * are constants.
1167 *
1168 * @param pos The source position to be used for error
1169 * diagnostics.
1170 * @param condtype The type of the expression's condition.
1171 * @param thentype The type of the expression's then-part.
1172 * @param elsetype The type of the expression's else-part.
1173 */
1174 private Type condType1(DiagnosticPosition pos, Type condtype,
1175 Type thentype, Type elsetype) {
1176 // If same type, that is the result
1177 if (types.isSameType(thentype, elsetype))
1178 return thentype.baseType();
1180 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1181 ? thentype : types.unboxedType(thentype);
1182 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1183 ? elsetype : types.unboxedType(elsetype);
1185 // Otherwise, if both arms can be converted to a numeric
1186 // type, return the least numeric type that fits both arms
1187 // (i.e. return larger of the two, or return int if one
1188 // arm is short, the other is char).
1189 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1190 // If one arm has an integer subrange type (i.e., byte,
1191 // short, or char), and the other is an integer constant
1192 // that fits into the subrange, return the subrange type.
1193 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1194 types.isAssignable(elseUnboxed, thenUnboxed))
1195 return thenUnboxed.baseType();
1196 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1197 types.isAssignable(thenUnboxed, elseUnboxed))
1198 return elseUnboxed.baseType();
1200 for (int i = BYTE; i < VOID; i++) {
1201 Type candidate = syms.typeOfTag[i];
1202 if (types.isSubtype(thenUnboxed, candidate) &&
1203 types.isSubtype(elseUnboxed, candidate))
1204 return candidate;
1205 }
1206 }
1208 // Those were all the cases that could result in a primitive
1209 if (allowBoxing) {
1210 if (thentype.isPrimitive())
1211 thentype = types.boxedClass(thentype).type;
1212 if (elsetype.isPrimitive())
1213 elsetype = types.boxedClass(elsetype).type;
1214 }
1216 if (types.isSubtype(thentype, elsetype))
1217 return elsetype.baseType();
1218 if (types.isSubtype(elsetype, thentype))
1219 return thentype.baseType();
1221 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1222 log.error(pos, "neither.conditional.subtype",
1223 thentype, elsetype);
1224 return thentype.baseType();
1225 }
1227 // both are known to be reference types. The result is
1228 // lub(thentype,elsetype). This cannot fail, as it will
1229 // always be possible to infer "Object" if nothing better.
1230 return types.lub(thentype.baseType(), elsetype.baseType());
1231 }
1233 public void visitIf(JCIf tree) {
1234 attribExpr(tree.cond, env, syms.booleanType);
1235 attribStat(tree.thenpart, env);
1236 if (tree.elsepart != null)
1237 attribStat(tree.elsepart, env);
1238 chk.checkEmptyIf(tree);
1239 result = null;
1240 }
1242 public void visitExec(JCExpressionStatement tree) {
1243 //a fresh environment is required for 292 inference to work properly ---
1244 //see Infer.instantiatePolymorphicSignatureInstance()
1245 Env<AttrContext> localEnv = env.dup(tree);
1246 attribExpr(tree.expr, localEnv);
1247 result = null;
1248 }
1250 public void visitBreak(JCBreak tree) {
1251 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1252 result = null;
1253 }
1255 public void visitContinue(JCContinue tree) {
1256 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1257 result = null;
1258 }
1259 //where
1260 /** Return the target of a break or continue statement, if it exists,
1261 * report an error if not.
1262 * Note: The target of a labelled break or continue is the
1263 * (non-labelled) statement tree referred to by the label,
1264 * not the tree representing the labelled statement itself.
1265 *
1266 * @param pos The position to be used for error diagnostics
1267 * @param tag The tag of the jump statement. This is either
1268 * Tree.BREAK or Tree.CONTINUE.
1269 * @param label The label of the jump statement, or null if no
1270 * label is given.
1271 * @param env The environment current at the jump statement.
1272 */
1273 private JCTree findJumpTarget(DiagnosticPosition pos,
1274 int tag,
1275 Name label,
1276 Env<AttrContext> env) {
1277 // Search environments outwards from the point of jump.
1278 Env<AttrContext> env1 = env;
1279 LOOP:
1280 while (env1 != null) {
1281 switch (env1.tree.getTag()) {
1282 case JCTree.LABELLED:
1283 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1284 if (label == labelled.label) {
1285 // If jump is a continue, check that target is a loop.
1286 if (tag == JCTree.CONTINUE) {
1287 if (labelled.body.getTag() != JCTree.DOLOOP &&
1288 labelled.body.getTag() != JCTree.WHILELOOP &&
1289 labelled.body.getTag() != JCTree.FORLOOP &&
1290 labelled.body.getTag() != JCTree.FOREACHLOOP)
1291 log.error(pos, "not.loop.label", label);
1292 // Found labelled statement target, now go inwards
1293 // to next non-labelled tree.
1294 return TreeInfo.referencedStatement(labelled);
1295 } else {
1296 return labelled;
1297 }
1298 }
1299 break;
1300 case JCTree.DOLOOP:
1301 case JCTree.WHILELOOP:
1302 case JCTree.FORLOOP:
1303 case JCTree.FOREACHLOOP:
1304 if (label == null) return env1.tree;
1305 break;
1306 case JCTree.SWITCH:
1307 if (label == null && tag == JCTree.BREAK) return env1.tree;
1308 break;
1309 case JCTree.METHODDEF:
1310 case JCTree.CLASSDEF:
1311 break LOOP;
1312 default:
1313 }
1314 env1 = env1.next;
1315 }
1316 if (label != null)
1317 log.error(pos, "undef.label", label);
1318 else if (tag == JCTree.CONTINUE)
1319 log.error(pos, "cont.outside.loop");
1320 else
1321 log.error(pos, "break.outside.switch.loop");
1322 return null;
1323 }
1325 public void visitReturn(JCReturn tree) {
1326 // Check that there is an enclosing method which is
1327 // nested within than the enclosing class.
1328 if (env.enclMethod == null ||
1329 env.enclMethod.sym.owner != env.enclClass.sym) {
1330 log.error(tree.pos(), "ret.outside.meth");
1332 } else {
1333 // Attribute return expression, if it exists, and check that
1334 // it conforms to result type of enclosing method.
1335 Symbol m = env.enclMethod.sym;
1336 if (m.type.getReturnType().tag == VOID) {
1337 if (tree.expr != null)
1338 log.error(tree.expr.pos(),
1339 "cant.ret.val.from.meth.decl.void");
1340 } else if (tree.expr == null) {
1341 log.error(tree.pos(), "missing.ret.val");
1342 } else {
1343 attribExpr(tree.expr, env, m.type.getReturnType());
1344 }
1345 }
1346 result = null;
1347 }
1349 public void visitThrow(JCThrow tree) {
1350 attribExpr(tree.expr, env, syms.throwableType);
1351 result = null;
1352 }
1354 public void visitAssert(JCAssert tree) {
1355 attribExpr(tree.cond, env, syms.booleanType);
1356 if (tree.detail != null) {
1357 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1358 }
1359 result = null;
1360 }
1362 /** Visitor method for method invocations.
1363 * NOTE: The method part of an application will have in its type field
1364 * the return type of the method, not the method's type itself!
1365 */
1366 public void visitApply(JCMethodInvocation tree) {
1367 // The local environment of a method application is
1368 // a new environment nested in the current one.
1369 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1371 // The types of the actual method arguments.
1372 List<Type> argtypes;
1374 // The types of the actual method type arguments.
1375 List<Type> typeargtypes = null;
1377 Name methName = TreeInfo.name(tree.meth);
1379 boolean isConstructorCall =
1380 methName == names._this || methName == names._super;
1382 if (isConstructorCall) {
1383 // We are seeing a ...this(...) or ...super(...) call.
1384 // Check that this is the first statement in a constructor.
1385 if (checkFirstConstructorStat(tree, env)) {
1387 // Record the fact
1388 // that this is a constructor call (using isSelfCall).
1389 localEnv.info.isSelfCall = true;
1391 // Attribute arguments, yielding list of argument types.
1392 argtypes = attribArgs(tree.args, localEnv);
1393 typeargtypes = attribTypes(tree.typeargs, localEnv);
1395 // Variable `site' points to the class in which the called
1396 // constructor is defined.
1397 Type site = env.enclClass.sym.type;
1398 if (methName == names._super) {
1399 if (site == syms.objectType) {
1400 log.error(tree.meth.pos(), "no.superclass", site);
1401 site = types.createErrorType(syms.objectType);
1402 } else {
1403 site = types.supertype(site);
1404 }
1405 }
1407 if (site.tag == CLASS) {
1408 Type encl = site.getEnclosingType();
1409 while (encl != null && encl.tag == TYPEVAR)
1410 encl = encl.getUpperBound();
1411 if (encl.tag == CLASS) {
1412 // we are calling a nested class
1414 if (tree.meth.getTag() == JCTree.SELECT) {
1415 JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1417 // We are seeing a prefixed call, of the form
1418 // <expr>.super(...).
1419 // Check that the prefix expression conforms
1420 // to the outer instance type of the class.
1421 chk.checkRefType(qualifier.pos(),
1422 attribExpr(qualifier, localEnv,
1423 encl));
1424 } else if (methName == names._super) {
1425 // qualifier omitted; check for existence
1426 // of an appropriate implicit qualifier.
1427 rs.resolveImplicitThis(tree.meth.pos(),
1428 localEnv, site, true);
1429 }
1430 } else if (tree.meth.getTag() == JCTree.SELECT) {
1431 log.error(tree.meth.pos(), "illegal.qual.not.icls",
1432 site.tsym);
1433 }
1435 // if we're calling a java.lang.Enum constructor,
1436 // prefix the implicit String and int parameters
1437 if (site.tsym == syms.enumSym && allowEnums)
1438 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1440 // Resolve the called constructor under the assumption
1441 // that we are referring to a superclass instance of the
1442 // current instance (JLS ???).
1443 boolean selectSuperPrev = localEnv.info.selectSuper;
1444 localEnv.info.selectSuper = true;
1445 localEnv.info.varArgs = false;
1446 Symbol sym = rs.resolveConstructor(
1447 tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1448 localEnv.info.selectSuper = selectSuperPrev;
1450 // Set method symbol to resolved constructor...
1451 TreeInfo.setSymbol(tree.meth, sym);
1453 // ...and check that it is legal in the current context.
1454 // (this will also set the tree's type)
1455 Type mpt = newMethTemplate(argtypes, typeargtypes);
1456 checkId(tree.meth, site, sym, localEnv, MTH,
1457 mpt, tree.varargsElement != null);
1458 }
1459 // Otherwise, `site' is an error type and we do nothing
1460 }
1461 result = tree.type = syms.voidType;
1462 } else {
1463 // Otherwise, we are seeing a regular method call.
1464 // Attribute the arguments, yielding list of argument types, ...
1465 argtypes = attribArgs(tree.args, localEnv);
1466 typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
1468 // ... and attribute the method using as a prototype a methodtype
1469 // whose formal argument types is exactly the list of actual
1470 // arguments (this will also set the method symbol).
1471 Type mpt = newMethTemplate(argtypes, typeargtypes);
1472 localEnv.info.varArgs = false;
1473 Type mtype = attribExpr(tree.meth, localEnv, mpt);
1474 if (localEnv.info.varArgs)
1475 Assert.check(mtype.isErroneous() || tree.varargsElement != null);
1477 // Compute the result type.
1478 Type restype = mtype.getReturnType();
1479 if (restype.tag == WILDCARD)
1480 throw new AssertionError(mtype);
1482 // as a special case, array.clone() has a result that is
1483 // the same as static type of the array being cloned
1484 if (tree.meth.getTag() == JCTree.SELECT &&
1485 allowCovariantReturns &&
1486 methName == names.clone &&
1487 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1488 restype = ((JCFieldAccess) tree.meth).selected.type;
1490 // as a special case, x.getClass() has type Class<? extends |X|>
1491 if (allowGenerics &&
1492 methName == names.getClass && tree.args.isEmpty()) {
1493 Type qualifier = (tree.meth.getTag() == JCTree.SELECT)
1494 ? ((JCFieldAccess) tree.meth).selected.type
1495 : env.enclClass.sym.type;
1496 restype = new
1497 ClassType(restype.getEnclosingType(),
1498 List.<Type>of(new WildcardType(types.erasure(qualifier),
1499 BoundKind.EXTENDS,
1500 syms.boundClass)),
1501 restype.tsym);
1502 }
1504 chk.checkRefTypes(tree.typeargs, typeargtypes);
1506 // Check that value of resulting type is admissible in the
1507 // current context. Also, capture the return type
1508 result = check(tree, capture(restype), VAL, pkind, pt);
1509 }
1510 chk.validate(tree.typeargs, localEnv);
1511 }
1512 //where
1513 /** Check that given application node appears as first statement
1514 * in a constructor call.
1515 * @param tree The application node
1516 * @param env The environment current at the application.
1517 */
1518 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1519 JCMethodDecl enclMethod = env.enclMethod;
1520 if (enclMethod != null && enclMethod.name == names.init) {
1521 JCBlock body = enclMethod.body;
1522 if (body.stats.head.getTag() == JCTree.EXEC &&
1523 ((JCExpressionStatement) body.stats.head).expr == tree)
1524 return true;
1525 }
1526 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1527 TreeInfo.name(tree.meth));
1528 return false;
1529 }
1531 /** Obtain a method type with given argument types.
1532 */
1533 Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
1534 MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
1535 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1536 }
1538 public void visitNewClass(JCNewClass tree) {
1539 Type owntype = types.createErrorType(tree.type);
1541 // The local environment of a class creation is
1542 // a new environment nested in the current one.
1543 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1545 // The anonymous inner class definition of the new expression,
1546 // if one is defined by it.
1547 JCClassDecl cdef = tree.def;
1549 // If enclosing class is given, attribute it, and
1550 // complete class name to be fully qualified
1551 JCExpression clazz = tree.clazz; // Class field following new
1552 JCExpression clazzid = // Identifier in class field
1553 (clazz.getTag() == JCTree.TYPEAPPLY)
1554 ? ((JCTypeApply) clazz).clazz
1555 : clazz;
1557 JCExpression clazzid1 = clazzid; // The same in fully qualified form
1559 if (tree.encl != null) {
1560 // We are seeing a qualified new, of the form
1561 // <expr>.new C <...> (...) ...
1562 // In this case, we let clazz stand for the name of the
1563 // allocated class C prefixed with the type of the qualifier
1564 // expression, so that we can
1565 // resolve it with standard techniques later. I.e., if
1566 // <expr> has type T, then <expr>.new C <...> (...)
1567 // yields a clazz T.C.
1568 Type encltype = chk.checkRefType(tree.encl.pos(),
1569 attribExpr(tree.encl, env));
1570 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1571 ((JCIdent) clazzid).name);
1572 if (clazz.getTag() == JCTree.TYPEAPPLY)
1573 clazz = make.at(tree.pos).
1574 TypeApply(clazzid1,
1575 ((JCTypeApply) clazz).arguments);
1576 else
1577 clazz = clazzid1;
1578 }
1580 // Attribute clazz expression and store
1581 // symbol + type back into the attributed tree.
1582 Type clazztype = attribType(clazz, env);
1583 Pair<Scope,Scope> mapping = getSyntheticScopeMapping(clazztype);
1584 clazztype = chk.checkDiamond(tree, clazztype);
1585 chk.validate(clazz, localEnv);
1586 if (tree.encl != null) {
1587 // We have to work in this case to store
1588 // symbol + type back into the attributed tree.
1589 tree.clazz.type = clazztype;
1590 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1591 clazzid.type = ((JCIdent) clazzid).sym.type;
1592 if (!clazztype.isErroneous()) {
1593 if (cdef != null && clazztype.tsym.isInterface()) {
1594 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1595 } else if (clazztype.tsym.isStatic()) {
1596 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1597 }
1598 }
1599 } else if (!clazztype.tsym.isInterface() &&
1600 clazztype.getEnclosingType().tag == CLASS) {
1601 // Check for the existence of an apropos outer instance
1602 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1603 }
1605 // Attribute constructor arguments.
1606 List<Type> argtypes = attribArgs(tree.args, localEnv);
1607 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1609 if (TreeInfo.isDiamond(tree) && !clazztype.isErroneous()) {
1610 clazztype = attribDiamond(localEnv, tree, clazztype, mapping, argtypes, typeargtypes);
1611 clazz.type = clazztype;
1612 } else if (allowDiamondFinder &&
1613 tree.def == null &&
1614 !clazztype.isErroneous() &&
1615 clazztype.getTypeArguments().nonEmpty() &&
1616 findDiamonds) {
1617 boolean prevDeferDiags = log.deferDiagnostics;
1618 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
1619 Type inferred = null;
1620 try {
1621 //disable diamond-related diagnostics
1622 log.deferDiagnostics = true;
1623 log.deferredDiagnostics = ListBuffer.lb();
1624 inferred = attribDiamond(localEnv,
1625 tree,
1626 clazztype,
1627 mapping,
1628 argtypes,
1629 typeargtypes);
1630 }
1631 finally {
1632 log.deferDiagnostics = prevDeferDiags;
1633 log.deferredDiagnostics = prevDeferredDiags;
1634 }
1635 if (inferred != null &&
1636 !inferred.isErroneous() &&
1637 inferred.tag == CLASS &&
1638 types.isAssignable(inferred, pt.tag == NONE ? clazztype : pt, Warner.noWarnings)) {
1639 String key = types.isSameType(clazztype, inferred) ?
1640 "diamond.redundant.args" :
1641 "diamond.redundant.args.1";
1642 log.warning(tree.clazz.pos(), key, clazztype, inferred);
1643 }
1644 }
1646 // If we have made no mistakes in the class type...
1647 if (clazztype.tag == CLASS) {
1648 // Enums may not be instantiated except implicitly
1649 if (allowEnums &&
1650 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1651 (env.tree.getTag() != JCTree.VARDEF ||
1652 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1653 ((JCVariableDecl) env.tree).init != tree))
1654 log.error(tree.pos(), "enum.cant.be.instantiated");
1655 // Check that class is not abstract
1656 if (cdef == null &&
1657 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1658 log.error(tree.pos(), "abstract.cant.be.instantiated",
1659 clazztype.tsym);
1660 } else if (cdef != null && clazztype.tsym.isInterface()) {
1661 // Check that no constructor arguments are given to
1662 // anonymous classes implementing an interface
1663 if (!argtypes.isEmpty())
1664 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1666 if (!typeargtypes.isEmpty())
1667 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1669 // Error recovery: pretend no arguments were supplied.
1670 argtypes = List.nil();
1671 typeargtypes = List.nil();
1672 }
1674 // Resolve the called constructor under the assumption
1675 // that we are referring to a superclass instance of the
1676 // current instance (JLS ???).
1677 else {
1678 localEnv.info.selectSuper = cdef != null;
1679 localEnv.info.varArgs = false;
1680 tree.constructor = rs.resolveConstructor(
1681 tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
1682 tree.constructorType = tree.constructor.type.isErroneous() ?
1683 syms.errType :
1684 checkMethod(clazztype,
1685 tree.constructor,
1686 localEnv,
1687 tree.args,
1688 argtypes,
1689 typeargtypes,
1690 localEnv.info.varArgs);
1691 if (localEnv.info.varArgs)
1692 Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
1693 }
1695 if (cdef != null) {
1696 // We are seeing an anonymous class instance creation.
1697 // In this case, the class instance creation
1698 // expression
1699 //
1700 // E.new <typeargs1>C<typargs2>(args) { ... }
1701 //
1702 // is represented internally as
1703 //
1704 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1705 //
1706 // This expression is then *transformed* as follows:
1707 //
1708 // (1) add a STATIC flag to the class definition
1709 // if the current environment is static
1710 // (2) add an extends or implements clause
1711 // (3) add a constructor.
1712 //
1713 // For instance, if C is a class, and ET is the type of E,
1714 // the expression
1715 //
1716 // E.new <typeargs1>C<typargs2>(args) { ... }
1717 //
1718 // is translated to (where X is a fresh name and typarams is the
1719 // parameter list of the super constructor):
1720 //
1721 // new <typeargs1>X(<*nullchk*>E, args) where
1722 // X extends C<typargs2> {
1723 // <typarams> X(ET e, args) {
1724 // e.<typeargs1>super(args)
1725 // }
1726 // ...
1727 // }
1728 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1730 if (clazztype.tsym.isInterface()) {
1731 cdef.implementing = List.of(clazz);
1732 } else {
1733 cdef.extending = clazz;
1734 }
1736 attribStat(cdef, localEnv);
1738 // If an outer instance is given,
1739 // prefix it to the constructor arguments
1740 // and delete it from the new expression
1741 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1742 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1743 argtypes = argtypes.prepend(tree.encl.type);
1744 tree.encl = null;
1745 }
1747 // Reassign clazztype and recompute constructor.
1748 clazztype = cdef.sym.type;
1749 Symbol sym = rs.resolveConstructor(
1750 tree.pos(), localEnv, clazztype, argtypes,
1751 typeargtypes, true, tree.varargsElement != null);
1752 Assert.check(sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous());
1753 tree.constructor = sym;
1754 if (tree.constructor.kind > ERRONEOUS) {
1755 tree.constructorType = syms.errType;
1756 }
1757 else {
1758 tree.constructorType = checkMethod(clazztype,
1759 tree.constructor,
1760 localEnv,
1761 tree.args,
1762 argtypes,
1763 typeargtypes,
1764 localEnv.info.varArgs);
1765 }
1766 }
1768 if (tree.constructor != null && tree.constructor.kind == MTH)
1769 owntype = clazztype;
1770 }
1771 result = check(tree, owntype, VAL, pkind, pt);
1772 chk.validate(tree.typeargs, localEnv);
1773 }
1775 Type attribDiamond(Env<AttrContext> env,
1776 JCNewClass tree,
1777 Type clazztype,
1778 Pair<Scope, Scope> mapping,
1779 List<Type> argtypes,
1780 List<Type> typeargtypes) {
1781 if (clazztype.isErroneous() ||
1782 clazztype.isInterface() ||
1783 mapping == erroneousMapping) {
1784 //if the type of the instance creation expression is erroneous,
1785 //or if it's an interface, or if something prevented us to form a valid
1786 //mapping, return the (possibly erroneous) type unchanged
1787 return clazztype;
1788 }
1790 //dup attribution environment and augment the set of inference variables
1791 Env<AttrContext> localEnv = env.dup(tree);
1792 localEnv.info.tvars = clazztype.tsym.type.getTypeArguments();
1794 //if the type of the instance creation expression is a class type
1795 //apply method resolution inference (JLS 15.12.2.7). The return type
1796 //of the resolved constructor will be a partially instantiated type
1797 ((ClassSymbol) clazztype.tsym).members_field = mapping.snd;
1798 Symbol constructor;
1799 try {
1800 constructor = rs.resolveDiamond(tree.pos(),
1801 localEnv,
1802 clazztype.tsym.type,
1803 argtypes,
1804 typeargtypes);
1805 } finally {
1806 ((ClassSymbol) clazztype.tsym).members_field = mapping.fst;
1807 }
1808 if (constructor.kind == MTH) {
1809 ClassType ct = new ClassType(clazztype.getEnclosingType(),
1810 clazztype.tsym.type.getTypeArguments(),
1811 clazztype.tsym);
1812 clazztype = checkMethod(ct,
1813 constructor,
1814 localEnv,
1815 tree.args,
1816 argtypes,
1817 typeargtypes,
1818 localEnv.info.varArgs).getReturnType();
1819 } else {
1820 clazztype = syms.errType;
1821 }
1823 if (clazztype.tag == FORALL && !pt.isErroneous()) {
1824 //if the resolved constructor's return type has some uninferred
1825 //type-variables, infer them using the expected type and declared
1826 //bounds (JLS 15.12.2.8).
1827 try {
1828 clazztype = infer.instantiateExpr((ForAll) clazztype,
1829 pt.tag == NONE ? syms.objectType : pt,
1830 Warner.noWarnings);
1831 } catch (Infer.InferenceException ex) {
1832 //an error occurred while inferring uninstantiated type-variables
1833 log.error(tree.clazz.pos(),
1834 "cant.apply.diamond.1",
1835 diags.fragment("diamond", clazztype.tsym),
1836 ex.diagnostic);
1837 }
1838 }
1839 return chk.checkClassType(tree.clazz.pos(),
1840 clazztype,
1841 true);
1842 }
1844 /** Creates a synthetic scope containing fake generic constructors.
1845 * Assuming that the original scope contains a constructor of the kind:
1846 * Foo(X x, Y y), where X,Y are class type-variables declared in Foo,
1847 * the synthetic scope is added a generic constructor of the kind:
1848 * <X,Y>Foo<X,Y>(X x, Y y). This is crucial in order to enable diamond
1849 * inference. The inferred return type of the synthetic constructor IS
1850 * the inferred type for the diamond operator.
1851 */
1852 private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype) {
1853 if (ctype.tag != CLASS) {
1854 return erroneousMapping;
1855 }
1857 Pair<Scope, Scope> mapping =
1858 new Pair<Scope, Scope>(ctype.tsym.members(), new Scope(ctype.tsym));
1860 //for each constructor in the original scope, create a synthetic constructor
1861 //whose return type is the type of the class in which the constructor is
1862 //declared, and insert it into the new scope.
1863 for (Scope.Entry e = mapping.fst.lookup(names.init);
1864 e.scope != null;
1865 e = e.next()) {
1866 Type synthRestype = new ClassType(ctype.getEnclosingType(),
1867 ctype.tsym.type.getTypeArguments(),
1868 ctype.tsym);
1869 MethodSymbol synhConstr = new MethodSymbol(e.sym.flags(),
1870 names.init,
1871 types.createMethodTypeWithReturn(e.sym.type, synthRestype),
1872 e.sym.owner);
1873 mapping.snd.enter(synhConstr);
1874 }
1875 return mapping;
1876 }
1878 private final Pair<Scope,Scope> erroneousMapping = new Pair<Scope,Scope>(null, null);
1880 /** Make an attributed null check tree.
1881 */
1882 public JCExpression makeNullCheck(JCExpression arg) {
1883 // optimization: X.this is never null; skip null check
1884 Name name = TreeInfo.name(arg);
1885 if (name == names._this || name == names._super) return arg;
1887 int optag = JCTree.NULLCHK;
1888 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1889 tree.operator = syms.nullcheck;
1890 tree.type = arg.type;
1891 return tree;
1892 }
1894 public void visitNewArray(JCNewArray tree) {
1895 Type owntype = types.createErrorType(tree.type);
1896 Type elemtype;
1897 if (tree.elemtype != null) {
1898 elemtype = attribType(tree.elemtype, env);
1899 chk.validate(tree.elemtype, env);
1900 owntype = elemtype;
1901 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1902 attribExpr(l.head, env, syms.intType);
1903 owntype = new ArrayType(owntype, syms.arrayClass);
1904 }
1905 } else {
1906 // we are seeing an untyped aggregate { ... }
1907 // this is allowed only if the prototype is an array
1908 if (pt.tag == ARRAY) {
1909 elemtype = types.elemtype(pt);
1910 } else {
1911 if (pt.tag != ERROR) {
1912 log.error(tree.pos(), "illegal.initializer.for.type",
1913 pt);
1914 }
1915 elemtype = types.createErrorType(pt);
1916 }
1917 }
1918 if (tree.elems != null) {
1919 attribExprs(tree.elems, env, elemtype);
1920 owntype = new ArrayType(elemtype, syms.arrayClass);
1921 }
1922 if (!types.isReifiable(elemtype))
1923 log.error(tree.pos(), "generic.array.creation");
1924 result = check(tree, owntype, VAL, pkind, pt);
1925 }
1927 public void visitParens(JCParens tree) {
1928 Type owntype = attribTree(tree.expr, env, pkind, pt);
1929 result = check(tree, owntype, pkind, pkind, pt);
1930 Symbol sym = TreeInfo.symbol(tree);
1931 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1932 log.error(tree.pos(), "illegal.start.of.type");
1933 }
1935 public void visitAssign(JCAssign tree) {
1936 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1937 Type capturedType = capture(owntype);
1938 attribExpr(tree.rhs, env, owntype);
1939 result = check(tree, capturedType, VAL, pkind, pt);
1940 }
1942 public void visitAssignop(JCAssignOp tree) {
1943 // Attribute arguments.
1944 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
1945 Type operand = attribExpr(tree.rhs, env);
1946 // Find operator.
1947 Symbol operator = tree.operator = rs.resolveBinaryOperator(
1948 tree.pos(), tree.getTag() - JCTree.ASGOffset, env,
1949 owntype, operand);
1951 if (operator.kind == MTH &&
1952 !owntype.isErroneous() &&
1953 !operand.isErroneous()) {
1954 chk.checkOperator(tree.pos(),
1955 (OperatorSymbol)operator,
1956 tree.getTag() - JCTree.ASGOffset,
1957 owntype,
1958 operand);
1959 chk.checkDivZero(tree.rhs.pos(), operator, operand);
1960 chk.checkCastable(tree.rhs.pos(),
1961 operator.type.getReturnType(),
1962 owntype);
1963 }
1964 result = check(tree, owntype, VAL, pkind, pt);
1965 }
1967 public void visitUnary(JCUnary tree) {
1968 // Attribute arguments.
1969 Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1970 ? attribTree(tree.arg, env, VAR, Type.noType)
1971 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
1973 // Find operator.
1974 Symbol operator = tree.operator =
1975 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
1977 Type owntype = types.createErrorType(tree.type);
1978 if (operator.kind == MTH &&
1979 !argtype.isErroneous()) {
1980 owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1981 ? tree.arg.type
1982 : operator.type.getReturnType();
1983 int opc = ((OperatorSymbol)operator).opcode;
1985 // If the argument is constant, fold it.
1986 if (argtype.constValue() != null) {
1987 Type ctype = cfolder.fold1(opc, argtype);
1988 if (ctype != null) {
1989 owntype = cfolder.coerce(ctype, owntype);
1991 // Remove constant types from arguments to
1992 // conserve space. The parser will fold concatenations
1993 // of string literals; the code here also
1994 // gets rid of intermediate results when some of the
1995 // operands are constant identifiers.
1996 if (tree.arg.type.tsym == syms.stringType.tsym) {
1997 tree.arg.type = syms.stringType;
1998 }
1999 }
2000 }
2001 }
2002 result = check(tree, owntype, VAL, pkind, pt);
2003 }
2005 public void visitBinary(JCBinary tree) {
2006 // Attribute arguments.
2007 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
2008 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
2010 // Find operator.
2011 Symbol operator = tree.operator =
2012 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
2014 Type owntype = types.createErrorType(tree.type);
2015 if (operator.kind == MTH &&
2016 !left.isErroneous() &&
2017 !right.isErroneous()) {
2018 owntype = operator.type.getReturnType();
2019 int opc = chk.checkOperator(tree.lhs.pos(),
2020 (OperatorSymbol)operator,
2021 tree.getTag(),
2022 left,
2023 right);
2025 // If both arguments are constants, fold them.
2026 if (left.constValue() != null && right.constValue() != null) {
2027 Type ctype = cfolder.fold2(opc, left, right);
2028 if (ctype != null) {
2029 owntype = cfolder.coerce(ctype, owntype);
2031 // Remove constant types from arguments to
2032 // conserve space. The parser will fold concatenations
2033 // of string literals; the code here also
2034 // gets rid of intermediate results when some of the
2035 // operands are constant identifiers.
2036 if (tree.lhs.type.tsym == syms.stringType.tsym) {
2037 tree.lhs.type = syms.stringType;
2038 }
2039 if (tree.rhs.type.tsym == syms.stringType.tsym) {
2040 tree.rhs.type = syms.stringType;
2041 }
2042 }
2043 }
2045 // Check that argument types of a reference ==, != are
2046 // castable to each other, (JLS???).
2047 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
2048 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
2049 log.error(tree.pos(), "incomparable.types", left, right);
2050 }
2051 }
2053 chk.checkDivZero(tree.rhs.pos(), operator, right);
2054 }
2055 result = check(tree, owntype, VAL, pkind, pt);
2056 }
2058 public void visitTypeCast(JCTypeCast tree) {
2059 Type clazztype = attribType(tree.clazz, env);
2060 chk.validate(tree.clazz, env, false);
2061 //a fresh environment is required for 292 inference to work properly ---
2062 //see Infer.instantiatePolymorphicSignatureInstance()
2063 Env<AttrContext> localEnv = env.dup(tree);
2064 Type exprtype = attribExpr(tree.expr, localEnv, Infer.anyPoly);
2065 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2066 if (exprtype.constValue() != null)
2067 owntype = cfolder.coerce(exprtype, owntype);
2068 result = check(tree, capture(owntype), VAL, pkind, pt);
2069 }
2071 public void visitTypeTest(JCInstanceOf tree) {
2072 Type exprtype = chk.checkNullOrRefType(
2073 tree.expr.pos(), attribExpr(tree.expr, env));
2074 Type clazztype = chk.checkReifiableReferenceType(
2075 tree.clazz.pos(), attribType(tree.clazz, env));
2076 chk.validate(tree.clazz, env, false);
2077 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2078 result = check(tree, syms.booleanType, VAL, pkind, pt);
2079 }
2081 public void visitIndexed(JCArrayAccess tree) {
2082 Type owntype = types.createErrorType(tree.type);
2083 Type atype = attribExpr(tree.indexed, env);
2084 attribExpr(tree.index, env, syms.intType);
2085 if (types.isArray(atype))
2086 owntype = types.elemtype(atype);
2087 else if (atype.tag != ERROR)
2088 log.error(tree.pos(), "array.req.but.found", atype);
2089 if ((pkind & VAR) == 0) owntype = capture(owntype);
2090 result = check(tree, owntype, VAR, pkind, pt);
2091 }
2093 public void visitIdent(JCIdent tree) {
2094 Symbol sym;
2095 boolean varArgs = false;
2097 // Find symbol
2098 if (pt.tag == METHOD || pt.tag == FORALL) {
2099 // If we are looking for a method, the prototype `pt' will be a
2100 // method type with the type of the call's arguments as parameters.
2101 env.info.varArgs = false;
2102 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
2103 varArgs = env.info.varArgs;
2104 } else if (tree.sym != null && tree.sym.kind != VAR) {
2105 sym = tree.sym;
2106 } else {
2107 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
2108 }
2109 tree.sym = sym;
2111 // (1) Also find the environment current for the class where
2112 // sym is defined (`symEnv').
2113 // Only for pre-tiger versions (1.4 and earlier):
2114 // (2) Also determine whether we access symbol out of an anonymous
2115 // class in a this or super call. This is illegal for instance
2116 // members since such classes don't carry a this$n link.
2117 // (`noOuterThisPath').
2118 Env<AttrContext> symEnv = env;
2119 boolean noOuterThisPath = false;
2120 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
2121 (sym.kind & (VAR | MTH | TYP)) != 0 &&
2122 sym.owner.kind == TYP &&
2123 tree.name != names._this && tree.name != names._super) {
2125 // Find environment in which identifier is defined.
2126 while (symEnv.outer != null &&
2127 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
2128 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
2129 noOuterThisPath = !allowAnonOuterThis;
2130 symEnv = symEnv.outer;
2131 }
2132 }
2134 // If symbol is a variable, ...
2135 if (sym.kind == VAR) {
2136 VarSymbol v = (VarSymbol)sym;
2138 // ..., evaluate its initializer, if it has one, and check for
2139 // illegal forward reference.
2140 checkInit(tree, env, v, false);
2142 // If symbol is a local variable accessed from an embedded
2143 // inner class check that it is final.
2144 if (v.owner.kind == MTH &&
2145 v.owner != env.info.scope.owner &&
2146 (v.flags_field & FINAL) == 0) {
2147 log.error(tree.pos(),
2148 "local.var.accessed.from.icls.needs.final",
2149 v);
2150 }
2152 // If we are expecting a variable (as opposed to a value), check
2153 // that the variable is assignable in the current environment.
2154 if (pkind == VAR)
2155 checkAssignable(tree.pos(), v, null, env);
2156 }
2158 // In a constructor body,
2159 // if symbol is a field or instance method, check that it is
2160 // not accessed before the supertype constructor is called.
2161 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
2162 (sym.kind & (VAR | MTH)) != 0 &&
2163 sym.owner.kind == TYP &&
2164 (sym.flags() & STATIC) == 0) {
2165 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
2166 }
2167 Env<AttrContext> env1 = env;
2168 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
2169 // If the found symbol is inaccessible, then it is
2170 // accessed through an enclosing instance. Locate this
2171 // enclosing instance:
2172 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
2173 env1 = env1.outer;
2174 }
2175 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
2176 }
2178 public void visitSelect(JCFieldAccess tree) {
2179 // Determine the expected kind of the qualifier expression.
2180 int skind = 0;
2181 if (tree.name == names._this || tree.name == names._super ||
2182 tree.name == names._class)
2183 {
2184 skind = TYP;
2185 } else {
2186 if ((pkind & PCK) != 0) skind = skind | PCK;
2187 if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
2188 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
2189 }
2191 // Attribute the qualifier expression, and determine its symbol (if any).
2192 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
2193 if ((pkind & (PCK | TYP)) == 0)
2194 site = capture(site); // Capture field access
2196 // don't allow T.class T[].class, etc
2197 if (skind == TYP) {
2198 Type elt = site;
2199 while (elt.tag == ARRAY)
2200 elt = ((ArrayType)elt).elemtype;
2201 if (elt.tag == TYPEVAR) {
2202 log.error(tree.pos(), "type.var.cant.be.deref");
2203 result = types.createErrorType(tree.type);
2204 return;
2205 }
2206 }
2208 // If qualifier symbol is a type or `super', assert `selectSuper'
2209 // for the selection. This is relevant for determining whether
2210 // protected symbols are accessible.
2211 Symbol sitesym = TreeInfo.symbol(tree.selected);
2212 boolean selectSuperPrev = env.info.selectSuper;
2213 env.info.selectSuper =
2214 sitesym != null &&
2215 sitesym.name == names._super;
2217 // If selected expression is polymorphic, strip
2218 // type parameters and remember in env.info.tvars, so that
2219 // they can be added later (in Attr.checkId and Infer.instantiateMethod).
2220 if (tree.selected.type.tag == FORALL) {
2221 ForAll pstype = (ForAll)tree.selected.type;
2222 env.info.tvars = pstype.tvars;
2223 site = tree.selected.type = pstype.qtype;
2224 }
2226 // Determine the symbol represented by the selection.
2227 env.info.varArgs = false;
2228 Symbol sym = selectSym(tree, sitesym, site, env, pt, pkind);
2229 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
2230 site = capture(site);
2231 sym = selectSym(tree, sitesym, site, env, pt, pkind);
2232 }
2233 boolean varArgs = env.info.varArgs;
2234 tree.sym = sym;
2236 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
2237 while (site.tag == TYPEVAR) site = site.getUpperBound();
2238 site = capture(site);
2239 }
2241 // If that symbol is a variable, ...
2242 if (sym.kind == VAR) {
2243 VarSymbol v = (VarSymbol)sym;
2245 // ..., evaluate its initializer, if it has one, and check for
2246 // illegal forward reference.
2247 checkInit(tree, env, v, true);
2249 // If we are expecting a variable (as opposed to a value), check
2250 // that the variable is assignable in the current environment.
2251 if (pkind == VAR)
2252 checkAssignable(tree.pos(), v, tree.selected, env);
2253 }
2255 if (sitesym != null &&
2256 sitesym.kind == VAR &&
2257 ((VarSymbol)sitesym).isResourceVariable() &&
2258 sym.kind == MTH &&
2259 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
2260 env.info.lint.isEnabled(LintCategory.TRY)) {
2261 log.warning(LintCategory.TRY, tree, "try.explicit.close.call");
2262 }
2264 // Disallow selecting a type from an expression
2265 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
2266 tree.type = check(tree.selected, pt,
2267 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
2268 }
2270 if (isType(sitesym)) {
2271 if (sym.name == names._this) {
2272 // If `C' is the currently compiled class, check that
2273 // C.this' does not appear in a call to a super(...)
2274 if (env.info.isSelfCall &&
2275 site.tsym == env.enclClass.sym) {
2276 chk.earlyRefError(tree.pos(), sym);
2277 }
2278 } else {
2279 // Check if type-qualified fields or methods are static (JLS)
2280 if ((sym.flags() & STATIC) == 0 &&
2281 sym.name != names._super &&
2282 (sym.kind == VAR || sym.kind == MTH)) {
2283 rs.access(rs.new StaticError(sym),
2284 tree.pos(), site, sym.name, true);
2285 }
2286 }
2287 } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
2288 // If the qualified item is not a type and the selected item is static, report
2289 // a warning. Make allowance for the class of an array type e.g. Object[].class)
2290 chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
2291 }
2293 // If we are selecting an instance member via a `super', ...
2294 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
2296 // Check that super-qualified symbols are not abstract (JLS)
2297 rs.checkNonAbstract(tree.pos(), sym);
2299 if (site.isRaw()) {
2300 // Determine argument types for site.
2301 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
2302 if (site1 != null) site = site1;
2303 }
2304 }
2306 env.info.selectSuper = selectSuperPrev;
2307 result = checkId(tree, site, sym, env, pkind, pt, varArgs);
2308 env.info.tvars = List.nil();
2309 }
2310 //where
2311 /** Determine symbol referenced by a Select expression,
2312 *
2313 * @param tree The select tree.
2314 * @param site The type of the selected expression,
2315 * @param env The current environment.
2316 * @param pt The current prototype.
2317 * @param pkind The expected kind(s) of the Select expression.
2318 */
2319 private Symbol selectSym(JCFieldAccess tree,
2320 Type site,
2321 Env<AttrContext> env,
2322 Type pt,
2323 int pkind) {
2324 return selectSym(tree, site.tsym, site, env, pt, pkind);
2325 }
2326 private Symbol selectSym(JCFieldAccess tree,
2327 Symbol location,
2328 Type site,
2329 Env<AttrContext> env,
2330 Type pt,
2331 int pkind) {
2332 DiagnosticPosition pos = tree.pos();
2333 Name name = tree.name;
2334 switch (site.tag) {
2335 case PACKAGE:
2336 return rs.access(
2337 rs.findIdentInPackage(env, site.tsym, name, pkind),
2338 pos, location, site, name, true);
2339 case ARRAY:
2340 case CLASS:
2341 if (pt.tag == METHOD || pt.tag == FORALL) {
2342 return rs.resolveQualifiedMethod(
2343 pos, env, location, site, name, pt.getParameterTypes(), pt.getTypeArguments());
2344 } else if (name == names._this || name == names._super) {
2345 return rs.resolveSelf(pos, env, site.tsym, name);
2346 } else if (name == names._class) {
2347 // In this case, we have already made sure in
2348 // visitSelect that qualifier expression is a type.
2349 Type t = syms.classType;
2350 List<Type> typeargs = allowGenerics
2351 ? List.of(types.erasure(site))
2352 : List.<Type>nil();
2353 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
2354 return new VarSymbol(
2355 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2356 } else {
2357 // We are seeing a plain identifier as selector.
2358 Symbol sym = rs.findIdentInType(env, site, name, pkind);
2359 if ((pkind & ERRONEOUS) == 0)
2360 sym = rs.access(sym, pos, location, site, name, true);
2361 return sym;
2362 }
2363 case WILDCARD:
2364 throw new AssertionError(tree);
2365 case TYPEVAR:
2366 // Normally, site.getUpperBound() shouldn't be null.
2367 // It should only happen during memberEnter/attribBase
2368 // when determining the super type which *must* beac
2369 // done before attributing the type variables. In
2370 // other words, we are seeing this illegal program:
2371 // class B<T> extends A<T.foo> {}
2372 Symbol sym = (site.getUpperBound() != null)
2373 ? selectSym(tree, location, capture(site.getUpperBound()), env, pt, pkind)
2374 : null;
2375 if (sym == null) {
2376 log.error(pos, "type.var.cant.be.deref");
2377 return syms.errSymbol;
2378 } else {
2379 Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
2380 rs.new AccessError(env, site, sym) :
2381 sym;
2382 rs.access(sym2, pos, location, site, name, true);
2383 return sym;
2384 }
2385 case ERROR:
2386 // preserve identifier names through errors
2387 return types.createErrorType(name, site.tsym, site).tsym;
2388 default:
2389 // The qualifier expression is of a primitive type -- only
2390 // .class is allowed for these.
2391 if (name == names._class) {
2392 // In this case, we have already made sure in Select that
2393 // qualifier expression is a type.
2394 Type t = syms.classType;
2395 Type arg = types.boxedClass(site).type;
2396 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2397 return new VarSymbol(
2398 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2399 } else {
2400 log.error(pos, "cant.deref", site);
2401 return syms.errSymbol;
2402 }
2403 }
2404 }
2406 /** Determine type of identifier or select expression and check that
2407 * (1) the referenced symbol is not deprecated
2408 * (2) the symbol's type is safe (@see checkSafe)
2409 * (3) if symbol is a variable, check that its type and kind are
2410 * compatible with the prototype and protokind.
2411 * (4) if symbol is an instance field of a raw type,
2412 * which is being assigned to, issue an unchecked warning if its
2413 * type changes under erasure.
2414 * (5) if symbol is an instance method of a raw type, issue an
2415 * unchecked warning if its argument types change under erasure.
2416 * If checks succeed:
2417 * If symbol is a constant, return its constant type
2418 * else if symbol is a method, return its result type
2419 * otherwise return its type.
2420 * Otherwise return errType.
2421 *
2422 * @param tree The syntax tree representing the identifier
2423 * @param site If this is a select, the type of the selected
2424 * expression, otherwise the type of the current class.
2425 * @param sym The symbol representing the identifier.
2426 * @param env The current environment.
2427 * @param pkind The set of expected kinds.
2428 * @param pt The expected type.
2429 */
2430 Type checkId(JCTree tree,
2431 Type site,
2432 Symbol sym,
2433 Env<AttrContext> env,
2434 int pkind,
2435 Type pt,
2436 boolean useVarargs) {
2437 if (pt.isErroneous()) return types.createErrorType(site);
2438 Type owntype; // The computed type of this identifier occurrence.
2439 switch (sym.kind) {
2440 case TYP:
2441 // For types, the computed type equals the symbol's type,
2442 // except for two situations:
2443 owntype = sym.type;
2444 if (owntype.tag == CLASS) {
2445 Type ownOuter = owntype.getEnclosingType();
2447 // (a) If the symbol's type is parameterized, erase it
2448 // because no type parameters were given.
2449 // We recover generic outer type later in visitTypeApply.
2450 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2451 owntype = types.erasure(owntype);
2452 }
2454 // (b) If the symbol's type is an inner class, then
2455 // we have to interpret its outer type as a superclass
2456 // of the site type. Example:
2457 //
2458 // class Tree<A> { class Visitor { ... } }
2459 // class PointTree extends Tree<Point> { ... }
2460 // ...PointTree.Visitor...
2461 //
2462 // Then the type of the last expression above is
2463 // Tree<Point>.Visitor.
2464 else if (ownOuter.tag == CLASS && site != ownOuter) {
2465 Type normOuter = site;
2466 if (normOuter.tag == CLASS)
2467 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2468 if (normOuter == null) // perhaps from an import
2469 normOuter = types.erasure(ownOuter);
2470 if (normOuter != ownOuter)
2471 owntype = new ClassType(
2472 normOuter, List.<Type>nil(), owntype.tsym);
2473 }
2474 }
2475 break;
2476 case VAR:
2477 VarSymbol v = (VarSymbol)sym;
2478 // Test (4): if symbol is an instance field of a raw type,
2479 // which is being assigned to, issue an unchecked warning if
2480 // its type changes under erasure.
2481 if (allowGenerics &&
2482 pkind == VAR &&
2483 v.owner.kind == TYP &&
2484 (v.flags() & STATIC) == 0 &&
2485 (site.tag == CLASS || site.tag == TYPEVAR)) {
2486 Type s = types.asOuterSuper(site, v.owner);
2487 if (s != null &&
2488 s.isRaw() &&
2489 !types.isSameType(v.type, v.erasure(types))) {
2490 chk.warnUnchecked(tree.pos(),
2491 "unchecked.assign.to.var",
2492 v, s);
2493 }
2494 }
2495 // The computed type of a variable is the type of the
2496 // variable symbol, taken as a member of the site type.
2497 owntype = (sym.owner.kind == TYP &&
2498 sym.name != names._this && sym.name != names._super)
2499 ? types.memberType(site, sym)
2500 : sym.type;
2502 if (env.info.tvars.nonEmpty()) {
2503 Type owntype1 = new ForAll(env.info.tvars, owntype);
2504 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2505 if (!owntype.contains(l.head)) {
2506 log.error(tree.pos(), "undetermined.type", owntype1);
2507 owntype1 = types.createErrorType(owntype1);
2508 }
2509 owntype = owntype1;
2510 }
2512 // If the variable is a constant, record constant value in
2513 // computed type.
2514 if (v.getConstValue() != null && isStaticReference(tree))
2515 owntype = owntype.constType(v.getConstValue());
2517 if (pkind == VAL) {
2518 owntype = capture(owntype); // capture "names as expressions"
2519 }
2520 break;
2521 case MTH: {
2522 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2523 owntype = checkMethod(site, sym, env, app.args,
2524 pt.getParameterTypes(), pt.getTypeArguments(),
2525 env.info.varArgs);
2526 break;
2527 }
2528 case PCK: case ERR:
2529 owntype = sym.type;
2530 break;
2531 default:
2532 throw new AssertionError("unexpected kind: " + sym.kind +
2533 " in tree " + tree);
2534 }
2536 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2537 // (for constructors, the error was given when the constructor was
2538 // resolved)
2540 if (sym.name != names.init) {
2541 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
2542 chk.checkSunAPI(tree.pos(), sym);
2543 }
2545 // Test (3): if symbol is a variable, check that its type and
2546 // kind are compatible with the prototype and protokind.
2547 return check(tree, owntype, sym.kind, pkind, pt);
2548 }
2550 /** Check that variable is initialized and evaluate the variable's
2551 * initializer, if not yet done. Also check that variable is not
2552 * referenced before it is defined.
2553 * @param tree The tree making up the variable reference.
2554 * @param env The current environment.
2555 * @param v The variable's symbol.
2556 */
2557 private void checkInit(JCTree tree,
2558 Env<AttrContext> env,
2559 VarSymbol v,
2560 boolean onlyWarning) {
2561 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2562 // tree.pos + " " + v.pos + " " +
2563 // Resolve.isStatic(env));//DEBUG
2565 // A forward reference is diagnosed if the declaration position
2566 // of the variable is greater than the current tree position
2567 // and the tree and variable definition occur in the same class
2568 // definition. Note that writes don't count as references.
2569 // This check applies only to class and instance
2570 // variables. Local variables follow different scope rules,
2571 // and are subject to definite assignment checking.
2572 if ((env.info.enclVar == v || v.pos > tree.pos) &&
2573 v.owner.kind == TYP &&
2574 canOwnInitializer(env.info.scope.owner) &&
2575 v.owner == env.info.scope.owner.enclClass() &&
2576 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2577 (env.tree.getTag() != JCTree.ASSIGN ||
2578 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2579 String suffix = (env.info.enclVar == v) ?
2580 "self.ref" : "forward.ref";
2581 if (!onlyWarning || isStaticEnumField(v)) {
2582 log.error(tree.pos(), "illegal." + suffix);
2583 } else if (useBeforeDeclarationWarning) {
2584 log.warning(tree.pos(), suffix, v);
2585 }
2586 }
2588 v.getConstValue(); // ensure initializer is evaluated
2590 checkEnumInitializer(tree, env, v);
2591 }
2593 /**
2594 * Check for illegal references to static members of enum. In
2595 * an enum type, constructors and initializers may not
2596 * reference its static members unless they are constant.
2597 *
2598 * @param tree The tree making up the variable reference.
2599 * @param env The current environment.
2600 * @param v The variable's symbol.
2601 * @see JLS 3rd Ed. (8.9 Enums)
2602 */
2603 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2604 // JLS 3rd Ed.:
2605 //
2606 // "It is a compile-time error to reference a static field
2607 // of an enum type that is not a compile-time constant
2608 // (15.28) from constructors, instance initializer blocks,
2609 // or instance variable initializer expressions of that
2610 // type. It is a compile-time error for the constructors,
2611 // instance initializer blocks, or instance variable
2612 // initializer expressions of an enum constant e to refer
2613 // to itself or to an enum constant of the same type that
2614 // is declared to the right of e."
2615 if (isStaticEnumField(v)) {
2616 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2618 if (enclClass == null || enclClass.owner == null)
2619 return;
2621 // See if the enclosing class is the enum (or a
2622 // subclass thereof) declaring v. If not, this
2623 // reference is OK.
2624 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2625 return;
2627 // If the reference isn't from an initializer, then
2628 // the reference is OK.
2629 if (!Resolve.isInitializer(env))
2630 return;
2632 log.error(tree.pos(), "illegal.enum.static.ref");
2633 }
2634 }
2636 /** Is the given symbol a static, non-constant field of an Enum?
2637 * Note: enum literals should not be regarded as such
2638 */
2639 private boolean isStaticEnumField(VarSymbol v) {
2640 return Flags.isEnum(v.owner) &&
2641 Flags.isStatic(v) &&
2642 !Flags.isConstant(v) &&
2643 v.name != names._class;
2644 }
2646 /** Can the given symbol be the owner of code which forms part
2647 * if class initialization? This is the case if the symbol is
2648 * a type or field, or if the symbol is the synthetic method.
2649 * owning a block.
2650 */
2651 private boolean canOwnInitializer(Symbol sym) {
2652 return
2653 (sym.kind & (VAR | TYP)) != 0 ||
2654 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2655 }
2657 Warner noteWarner = new Warner();
2659 /**
2660 * Check that method arguments conform to its instantation.
2661 **/
2662 public Type checkMethod(Type site,
2663 Symbol sym,
2664 Env<AttrContext> env,
2665 final List<JCExpression> argtrees,
2666 List<Type> argtypes,
2667 List<Type> typeargtypes,
2668 boolean useVarargs) {
2669 // Test (5): if symbol is an instance method of a raw type, issue
2670 // an unchecked warning if its argument types change under erasure.
2671 if (allowGenerics &&
2672 (sym.flags() & STATIC) == 0 &&
2673 (site.tag == CLASS || site.tag == TYPEVAR)) {
2674 Type s = types.asOuterSuper(site, sym.owner);
2675 if (s != null && s.isRaw() &&
2676 !types.isSameTypes(sym.type.getParameterTypes(),
2677 sym.erasure(types).getParameterTypes())) {
2678 chk.warnUnchecked(env.tree.pos(),
2679 "unchecked.call.mbr.of.raw.type",
2680 sym, s);
2681 }
2682 }
2684 // Compute the identifier's instantiated type.
2685 // For methods, we need to compute the instance type by
2686 // Resolve.instantiate from the symbol's type as well as
2687 // any type arguments and value arguments.
2688 noteWarner.clear();
2689 Type owntype = rs.instantiate(env,
2690 site,
2691 sym,
2692 argtypes,
2693 typeargtypes,
2694 true,
2695 useVarargs,
2696 noteWarner);
2697 boolean warned = noteWarner.hasNonSilentLint(LintCategory.UNCHECKED);
2699 // If this fails, something went wrong; we should not have
2700 // found the identifier in the first place.
2701 if (owntype == null) {
2702 if (!pt.isErroneous())
2703 log.error(env.tree.pos(),
2704 "internal.error.cant.instantiate",
2705 sym, site,
2706 Type.toString(pt.getParameterTypes()));
2707 owntype = types.createErrorType(site);
2708 } else {
2709 // System.out.println("call : " + env.tree);
2710 // System.out.println("method : " + owntype);
2711 // System.out.println("actuals: " + argtypes);
2712 List<Type> formals = owntype.getParameterTypes();
2713 Type last = useVarargs ? formals.last() : null;
2714 if (sym.name==names.init &&
2715 sym.owner == syms.enumSym)
2716 formals = formals.tail.tail;
2717 List<JCExpression> args = argtrees;
2718 while (formals.head != last) {
2719 JCTree arg = args.head;
2720 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2721 assertConvertible(arg, arg.type, formals.head, warn);
2722 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED);
2723 args = args.tail;
2724 formals = formals.tail;
2725 }
2726 if (useVarargs) {
2727 Type varArg = types.elemtype(last);
2728 while (args.tail != null) {
2729 JCTree arg = args.head;
2730 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2731 assertConvertible(arg, arg.type, varArg, warn);
2732 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED);
2733 args = args.tail;
2734 }
2735 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2736 // non-varargs call to varargs method
2737 Type varParam = owntype.getParameterTypes().last();
2738 Type lastArg = argtypes.last();
2739 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2740 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2741 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2742 types.elemtype(varParam),
2743 varParam);
2744 }
2746 if (warned && sym.type.tag == FORALL) {
2747 chk.warnUnchecked(env.tree.pos(),
2748 "unchecked.meth.invocation.applied",
2749 kindName(sym),
2750 sym.name,
2751 rs.methodArguments(sym.type.getParameterTypes()),
2752 rs.methodArguments(argtypes),
2753 kindName(sym.location()),
2754 sym.location());
2755 owntype = new MethodType(owntype.getParameterTypes(),
2756 types.erasure(owntype.getReturnType()),
2757 types.erasure(owntype.getThrownTypes()),
2758 syms.methodClass);
2759 }
2760 if (useVarargs) {
2761 JCTree tree = env.tree;
2762 Type argtype = owntype.getParameterTypes().last();
2763 if (owntype.getReturnType().tag != FORALL || warned) {
2764 chk.checkVararg(env.tree.pos(), owntype.getParameterTypes(), sym);
2765 }
2766 Type elemtype = types.elemtype(argtype);
2767 switch (tree.getTag()) {
2768 case JCTree.APPLY:
2769 ((JCMethodInvocation) tree).varargsElement = elemtype;
2770 break;
2771 case JCTree.NEWCLASS:
2772 ((JCNewClass) tree).varargsElement = elemtype;
2773 break;
2774 default:
2775 throw new AssertionError(""+tree);
2776 }
2777 }
2778 }
2779 return owntype;
2780 }
2782 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2783 if (types.isConvertible(actual, formal, warn))
2784 return;
2786 if (formal.isCompound()
2787 && types.isSubtype(actual, types.supertype(formal))
2788 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2789 return;
2791 if (false) {
2792 // TODO: make assertConvertible work
2793 chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal);
2794 throw new AssertionError("Tree: " + tree
2795 + " actual:" + actual
2796 + " formal: " + formal);
2797 }
2798 }
2800 public void visitLiteral(JCLiteral tree) {
2801 result = check(
2802 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2803 }
2804 //where
2805 /** Return the type of a literal with given type tag.
2806 */
2807 Type litType(int tag) {
2808 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2809 }
2811 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2812 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2813 }
2815 public void visitTypeArray(JCArrayTypeTree tree) {
2816 Type etype = attribType(tree.elemtype, env);
2817 Type type = new ArrayType(etype, syms.arrayClass);
2818 result = check(tree, type, TYP, pkind, pt);
2819 }
2821 /** Visitor method for parameterized types.
2822 * Bound checking is left until later, since types are attributed
2823 * before supertype structure is completely known
2824 */
2825 public void visitTypeApply(JCTypeApply tree) {
2826 Type owntype = types.createErrorType(tree.type);
2828 // Attribute functor part of application and make sure it's a class.
2829 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2831 // Attribute type parameters
2832 List<Type> actuals = attribTypes(tree.arguments, env);
2834 if (clazztype.tag == CLASS) {
2835 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2837 if (actuals.length() == formals.length() || actuals.length() == 0) {
2838 List<Type> a = actuals;
2839 List<Type> f = formals;
2840 while (a.nonEmpty()) {
2841 a.head = a.head.withTypeVar(f.head);
2842 a = a.tail;
2843 f = f.tail;
2844 }
2845 // Compute the proper generic outer
2846 Type clazzOuter = clazztype.getEnclosingType();
2847 if (clazzOuter.tag == CLASS) {
2848 Type site;
2849 JCExpression clazz = TreeInfo.typeIn(tree.clazz);
2850 if (clazz.getTag() == JCTree.IDENT) {
2851 site = env.enclClass.sym.type;
2852 } else if (clazz.getTag() == JCTree.SELECT) {
2853 site = ((JCFieldAccess) clazz).selected.type;
2854 } else throw new AssertionError(""+tree);
2855 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2856 if (site.tag == CLASS)
2857 site = types.asOuterSuper(site, clazzOuter.tsym);
2858 if (site == null)
2859 site = types.erasure(clazzOuter);
2860 clazzOuter = site;
2861 }
2862 }
2863 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2864 } else {
2865 if (formals.length() != 0) {
2866 log.error(tree.pos(), "wrong.number.type.args",
2867 Integer.toString(formals.length()));
2868 } else {
2869 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2870 }
2871 owntype = types.createErrorType(tree.type);
2872 }
2873 }
2874 result = check(tree, owntype, TYP, pkind, pt);
2875 }
2877 public void visitTypeDisjunction(JCTypeDisjunction tree) {
2878 ListBuffer<Type> multicatchTypes = ListBuffer.lb();
2879 for (JCExpression typeTree : tree.alternatives) {
2880 Type ctype = attribType(typeTree, env);
2881 ctype = chk.checkType(typeTree.pos(),
2882 chk.checkClassType(typeTree.pos(), ctype),
2883 syms.throwableType);
2884 if (!ctype.isErroneous()) {
2885 //check that alternatives of a disjunctive type are pairwise
2886 //unrelated w.r.t. subtyping
2887 if (chk.intersects(ctype, multicatchTypes.toList())) {
2888 for (Type t : multicatchTypes) {
2889 boolean sub = types.isSubtype(ctype, t);
2890 boolean sup = types.isSubtype(t, ctype);
2891 if (sub || sup) {
2892 //assume 'a' <: 'b'
2893 Type a = sub ? ctype : t;
2894 Type b = sub ? t : ctype;
2895 log.error(typeTree.pos(), "multicatch.types.must.be.disjoint", a, b);
2896 }
2897 }
2898 }
2899 multicatchTypes.append(ctype);
2900 }
2901 }
2902 tree.type = result = check(tree, types.lub(multicatchTypes.toList()), TYP, pkind, pt);
2903 }
2905 public void visitTypeParameter(JCTypeParameter tree) {
2906 TypeVar a = (TypeVar)tree.type;
2907 Set<Type> boundSet = new HashSet<Type>();
2908 if (a.bound.isErroneous())
2909 return;
2910 List<Type> bs = types.getBounds(a);
2911 if (tree.bounds.nonEmpty()) {
2912 // accept class or interface or typevar as first bound.
2913 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2914 boundSet.add(types.erasure(b));
2915 if (b.isErroneous()) {
2916 a.bound = b;
2917 }
2918 else if (b.tag == TYPEVAR) {
2919 // if first bound was a typevar, do not accept further bounds.
2920 if (tree.bounds.tail.nonEmpty()) {
2921 log.error(tree.bounds.tail.head.pos(),
2922 "type.var.may.not.be.followed.by.other.bounds");
2923 tree.bounds = List.of(tree.bounds.head);
2924 a.bound = bs.head;
2925 }
2926 } else {
2927 // if first bound was a class or interface, accept only interfaces
2928 // as further bounds.
2929 for (JCExpression bound : tree.bounds.tail) {
2930 bs = bs.tail;
2931 Type i = checkBase(bs.head, bound, env, false, true, false);
2932 if (i.isErroneous())
2933 a.bound = i;
2934 else if (i.tag == CLASS)
2935 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
2936 }
2937 }
2938 }
2939 bs = types.getBounds(a);
2941 // in case of multiple bounds ...
2942 if (bs.length() > 1) {
2943 // ... the variable's bound is a class type flagged COMPOUND
2944 // (see comment for TypeVar.bound).
2945 // In this case, generate a class tree that represents the
2946 // bound class, ...
2947 JCExpression extending;
2948 List<JCExpression> implementing;
2949 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
2950 extending = tree.bounds.head;
2951 implementing = tree.bounds.tail;
2952 } else {
2953 extending = null;
2954 implementing = tree.bounds;
2955 }
2956 JCClassDecl cd = make.at(tree.pos).ClassDef(
2957 make.Modifiers(PUBLIC | ABSTRACT),
2958 tree.name, List.<JCTypeParameter>nil(),
2959 extending, implementing, List.<JCTree>nil());
2961 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
2962 Assert.check((c.flags() & COMPOUND) != 0);
2963 cd.sym = c;
2964 c.sourcefile = env.toplevel.sourcefile;
2966 // ... and attribute the bound class
2967 c.flags_field |= UNATTRIBUTED;
2968 Env<AttrContext> cenv = enter.classEnv(cd, env);
2969 enter.typeEnvs.put(c, cenv);
2970 }
2971 }
2974 public void visitWildcard(JCWildcard tree) {
2975 //- System.err.println("visitWildcard("+tree+");");//DEBUG
2976 Type type = (tree.kind.kind == BoundKind.UNBOUND)
2977 ? syms.objectType
2978 : attribType(tree.inner, env);
2979 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
2980 tree.kind.kind,
2981 syms.boundClass),
2982 TYP, pkind, pt);
2983 }
2985 public void visitAnnotation(JCAnnotation tree) {
2986 log.error(tree.pos(), "annotation.not.valid.for.type", pt);
2987 result = tree.type = syms.errType;
2988 }
2990 public void visitErroneous(JCErroneous tree) {
2991 if (tree.errs != null)
2992 for (JCTree err : tree.errs)
2993 attribTree(err, env, ERR, pt);
2994 result = tree.type = syms.errType;
2995 }
2997 /** Default visitor method for all other trees.
2998 */
2999 public void visitTree(JCTree tree) {
3000 throw new AssertionError();
3001 }
3003 /**
3004 * Attribute an env for either a top level tree or class declaration.
3005 */
3006 public void attrib(Env<AttrContext> env) {
3007 if (env.tree.getTag() == JCTree.TOPLEVEL)
3008 attribTopLevel(env);
3009 else
3010 attribClass(env.tree.pos(), env.enclClass.sym);
3011 }
3013 /**
3014 * Attribute a top level tree. These trees are encountered when the
3015 * package declaration has annotations.
3016 */
3017 public void attribTopLevel(Env<AttrContext> env) {
3018 JCCompilationUnit toplevel = env.toplevel;
3019 try {
3020 annotate.flush();
3021 chk.validateAnnotations(toplevel.packageAnnotations, toplevel.packge);
3022 } catch (CompletionFailure ex) {
3023 chk.completionError(toplevel.pos(), ex);
3024 }
3025 }
3027 /** Main method: attribute class definition associated with given class symbol.
3028 * reporting completion failures at the given position.
3029 * @param pos The source position at which completion errors are to be
3030 * reported.
3031 * @param c The class symbol whose definition will be attributed.
3032 */
3033 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
3034 try {
3035 annotate.flush();
3036 attribClass(c);
3037 } catch (CompletionFailure ex) {
3038 chk.completionError(pos, ex);
3039 }
3040 }
3042 /** Attribute class definition associated with given class symbol.
3043 * @param c The class symbol whose definition will be attributed.
3044 */
3045 void attribClass(ClassSymbol c) throws CompletionFailure {
3046 if (c.type.tag == ERROR) return;
3048 // Check for cycles in the inheritance graph, which can arise from
3049 // ill-formed class files.
3050 chk.checkNonCyclic(null, c.type);
3052 Type st = types.supertype(c.type);
3053 if ((c.flags_field & Flags.COMPOUND) == 0) {
3054 // First, attribute superclass.
3055 if (st.tag == CLASS)
3056 attribClass((ClassSymbol)st.tsym);
3058 // Next attribute owner, if it is a class.
3059 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
3060 attribClass((ClassSymbol)c.owner);
3061 }
3063 // The previous operations might have attributed the current class
3064 // if there was a cycle. So we test first whether the class is still
3065 // UNATTRIBUTED.
3066 if ((c.flags_field & UNATTRIBUTED) != 0) {
3067 c.flags_field &= ~UNATTRIBUTED;
3069 // Get environment current at the point of class definition.
3070 Env<AttrContext> env = enter.typeEnvs.get(c);
3072 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
3073 // because the annotations were not available at the time the env was created. Therefore,
3074 // we look up the environment chain for the first enclosing environment for which the
3075 // lint value is set. Typically, this is the parent env, but might be further if there
3076 // are any envs created as a result of TypeParameter nodes.
3077 Env<AttrContext> lintEnv = env;
3078 while (lintEnv.info.lint == null)
3079 lintEnv = lintEnv.next;
3081 // Having found the enclosing lint value, we can initialize the lint value for this class
3082 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
3084 Lint prevLint = chk.setLint(env.info.lint);
3085 JavaFileObject prev = log.useSource(c.sourcefile);
3087 try {
3088 // java.lang.Enum may not be subclassed by a non-enum
3089 if (st.tsym == syms.enumSym &&
3090 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
3091 log.error(env.tree.pos(), "enum.no.subclassing");
3093 // Enums may not be extended by source-level classes
3094 if (st.tsym != null &&
3095 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
3096 ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
3097 !target.compilerBootstrap(c)) {
3098 log.error(env.tree.pos(), "enum.types.not.extensible");
3099 }
3100 attribClassBody(env, c);
3102 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
3103 } finally {
3104 log.useSource(prev);
3105 chk.setLint(prevLint);
3106 }
3108 }
3109 }
3111 public void visitImport(JCImport tree) {
3112 // nothing to do
3113 }
3115 /** Finish the attribution of a class. */
3116 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
3117 JCClassDecl tree = (JCClassDecl)env.tree;
3118 Assert.check(c == tree.sym);
3120 // Validate annotations
3121 chk.validateAnnotations(tree.mods.annotations, c);
3123 // Validate type parameters, supertype and interfaces.
3124 attribBounds(tree.typarams);
3125 if (!c.isAnonymous()) {
3126 //already checked if anonymous
3127 chk.validate(tree.typarams, env);
3128 chk.validate(tree.extending, env);
3129 chk.validate(tree.implementing, env);
3130 }
3132 // If this is a non-abstract class, check that it has no abstract
3133 // methods or unimplemented methods of an implemented interface.
3134 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
3135 if (!relax)
3136 chk.checkAllDefined(tree.pos(), c);
3137 }
3139 if ((c.flags() & ANNOTATION) != 0) {
3140 if (tree.implementing.nonEmpty())
3141 log.error(tree.implementing.head.pos(),
3142 "cant.extend.intf.annotation");
3143 if (tree.typarams.nonEmpty())
3144 log.error(tree.typarams.head.pos(),
3145 "intf.annotation.cant.have.type.params");
3146 } else {
3147 // Check that all extended classes and interfaces
3148 // are compatible (i.e. no two define methods with same arguments
3149 // yet different return types). (JLS 8.4.6.3)
3150 chk.checkCompatibleSupertypes(tree.pos(), c.type);
3151 }
3153 // Check that class does not import the same parameterized interface
3154 // with two different argument lists.
3155 chk.checkClassBounds(tree.pos(), c.type);
3157 tree.type = c.type;
3159 for (List<JCTypeParameter> l = tree.typarams;
3160 l.nonEmpty(); l = l.tail) {
3161 Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope);
3162 }
3164 // Check that a generic class doesn't extend Throwable
3165 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
3166 log.error(tree.extending.pos(), "generic.throwable");
3168 // Check that all methods which implement some
3169 // method conform to the method they implement.
3170 chk.checkImplementations(tree);
3172 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3173 // Attribute declaration
3174 attribStat(l.head, env);
3175 // Check that declarations in inner classes are not static (JLS 8.1.2)
3176 // Make an exception for static constants.
3177 if (c.owner.kind != PCK &&
3178 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
3179 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
3180 Symbol sym = null;
3181 if (l.head.getTag() == JCTree.VARDEF) sym = ((JCVariableDecl) l.head).sym;
3182 if (sym == null ||
3183 sym.kind != VAR ||
3184 ((VarSymbol) sym).getConstValue() == null)
3185 log.error(l.head.pos(), "icls.cant.have.static.decl", c);
3186 }
3187 }
3189 // Check for cycles among non-initial constructors.
3190 chk.checkCyclicConstructors(tree);
3192 // Check for cycles among annotation elements.
3193 chk.checkNonCyclicElements(tree);
3195 // Check for proper use of serialVersionUID
3196 if (env.info.lint.isEnabled(LintCategory.SERIAL) &&
3197 isSerializable(c) &&
3198 (c.flags() & Flags.ENUM) == 0 &&
3199 (c.flags() & ABSTRACT) == 0) {
3200 checkSerialVersionUID(tree, c);
3201 }
3202 }
3203 // where
3204 /** check if a class is a subtype of Serializable, if that is available. */
3205 private boolean isSerializable(ClassSymbol c) {
3206 try {
3207 syms.serializableType.complete();
3208 }
3209 catch (CompletionFailure e) {
3210 return false;
3211 }
3212 return types.isSubtype(c.type, syms.serializableType);
3213 }
3215 /** Check that an appropriate serialVersionUID member is defined. */
3216 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
3218 // check for presence of serialVersionUID
3219 Scope.Entry e = c.members().lookup(names.serialVersionUID);
3220 while (e.scope != null && e.sym.kind != VAR) e = e.next();
3221 if (e.scope == null) {
3222 log.warning(LintCategory.SERIAL,
3223 tree.pos(), "missing.SVUID", c);
3224 return;
3225 }
3227 // check that it is static final
3228 VarSymbol svuid = (VarSymbol)e.sym;
3229 if ((svuid.flags() & (STATIC | FINAL)) !=
3230 (STATIC | FINAL))
3231 log.warning(LintCategory.SERIAL,
3232 TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
3234 // check that it is long
3235 else if (svuid.type.tag != TypeTags.LONG)
3236 log.warning(LintCategory.SERIAL,
3237 TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
3239 // check constant
3240 else if (svuid.getConstValue() == null)
3241 log.warning(LintCategory.SERIAL,
3242 TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
3243 }
3245 private Type capture(Type type) {
3246 return types.capture(type);
3247 }
3249 // <editor-fold desc="post-attribution visitor">
3251 /**
3252 * Handle missing types/symbols in an AST. This routine is useful when
3253 * the compiler has encountered some errors (which might have ended up
3254 * terminating attribution abruptly); if the compiler is used in fail-over
3255 * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
3256 * prevents NPE to be progagated during subsequent compilation steps.
3257 */
3258 public void postAttr(Env<AttrContext> env) {
3259 new PostAttrAnalyzer().scan(env.tree);
3260 }
3262 class PostAttrAnalyzer extends TreeScanner {
3264 private void initTypeIfNeeded(JCTree that) {
3265 if (that.type == null) {
3266 that.type = syms.unknownType;
3267 }
3268 }
3270 @Override
3271 public void scan(JCTree tree) {
3272 if (tree == null) return;
3273 if (tree instanceof JCExpression) {
3274 initTypeIfNeeded(tree);
3275 }
3276 super.scan(tree);
3277 }
3279 @Override
3280 public void visitIdent(JCIdent that) {
3281 if (that.sym == null) {
3282 that.sym = syms.unknownSymbol;
3283 }
3284 }
3286 @Override
3287 public void visitSelect(JCFieldAccess that) {
3288 if (that.sym == null) {
3289 that.sym = syms.unknownSymbol;
3290 }
3291 super.visitSelect(that);
3292 }
3294 @Override
3295 public void visitClassDef(JCClassDecl that) {
3296 initTypeIfNeeded(that);
3297 if (that.sym == null) {
3298 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
3299 }
3300 super.visitClassDef(that);
3301 }
3303 @Override
3304 public void visitMethodDef(JCMethodDecl that) {
3305 initTypeIfNeeded(that);
3306 if (that.sym == null) {
3307 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
3308 }
3309 super.visitMethodDef(that);
3310 }
3312 @Override
3313 public void visitVarDef(JCVariableDecl that) {
3314 initTypeIfNeeded(that);
3315 if (that.sym == null) {
3316 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
3317 that.sym.adr = 0;
3318 }
3319 super.visitVarDef(that);
3320 }
3322 @Override
3323 public void visitNewClass(JCNewClass that) {
3324 if (that.constructor == null) {
3325 that.constructor = new MethodSymbol(0, names.init, syms.unknownType, syms.noSymbol);
3326 }
3327 if (that.constructorType == null) {
3328 that.constructorType = syms.unknownType;
3329 }
3330 super.visitNewClass(that);
3331 }
3333 @Override
3334 public void visitBinary(JCBinary that) {
3335 if (that.operator == null)
3336 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3337 super.visitBinary(that);
3338 }
3340 @Override
3341 public void visitUnary(JCUnary that) {
3342 if (that.operator == null)
3343 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3344 super.visitUnary(that);
3345 }
3346 }
3347 // </editor-fold>
3348 }