Mon, 07 Feb 2011 18:10:13 +0000
7007615: java_util/generics/phase2/NameClashTest02 fails since jdk7/pit/b123.
Summary: override clash algorithm is not implemented correctly
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);
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, cdef != null);
1584 if (!TreeInfo.isDiamond(tree)) {
1585 clazztype = chk.checkClassType(
1586 tree.clazz.pos(), clazztype, true);
1587 }
1588 chk.validate(clazz, localEnv);
1589 if (tree.encl != null) {
1590 // We have to work in this case to store
1591 // symbol + type back into the attributed tree.
1592 tree.clazz.type = clazztype;
1593 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1594 clazzid.type = ((JCIdent) clazzid).sym.type;
1595 if (!clazztype.isErroneous()) {
1596 if (cdef != null && clazztype.tsym.isInterface()) {
1597 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1598 } else if (clazztype.tsym.isStatic()) {
1599 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1600 }
1601 }
1602 } else if (!clazztype.tsym.isInterface() &&
1603 clazztype.getEnclosingType().tag == CLASS) {
1604 // Check for the existence of an apropos outer instance
1605 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1606 }
1608 // Attribute constructor arguments.
1609 List<Type> argtypes = attribArgs(tree.args, localEnv);
1610 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1612 if (TreeInfo.isDiamond(tree)) {
1613 clazztype = attribDiamond(localEnv, tree, clazztype, mapping, argtypes, typeargtypes);
1614 clazz.type = clazztype;
1615 } else if (allowDiamondFinder &&
1616 clazztype.getTypeArguments().nonEmpty() &&
1617 findDiamonds) {
1618 boolean prevDeferDiags = log.deferDiagnostics;
1619 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
1620 Type inferred = null;
1621 try {
1622 //disable diamond-related diagnostics
1623 log.deferDiagnostics = true;
1624 log.deferredDiagnostics = ListBuffer.lb();
1625 inferred = attribDiamond(localEnv,
1626 tree,
1627 clazztype,
1628 mapping,
1629 argtypes,
1630 typeargtypes);
1631 }
1632 finally {
1633 log.deferDiagnostics = prevDeferDiags;
1634 log.deferredDiagnostics = prevDeferredDiags;
1635 }
1636 if (inferred != null &&
1637 !inferred.isErroneous() &&
1638 inferred.tag == CLASS &&
1639 types.isAssignable(inferred, pt.tag == NONE ? clazztype : pt, Warner.noWarnings) &&
1640 chk.checkDiamond((ClassType)inferred).isEmpty()) {
1641 String key = types.isSameType(clazztype, inferred) ?
1642 "diamond.redundant.args" :
1643 "diamond.redundant.args.1";
1644 log.warning(tree.clazz.pos(), key, clazztype, inferred);
1645 }
1646 }
1648 // If we have made no mistakes in the class type...
1649 if (clazztype.tag == CLASS) {
1650 // Enums may not be instantiated except implicitly
1651 if (allowEnums &&
1652 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1653 (env.tree.getTag() != JCTree.VARDEF ||
1654 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1655 ((JCVariableDecl) env.tree).init != tree))
1656 log.error(tree.pos(), "enum.cant.be.instantiated");
1657 // Check that class is not abstract
1658 if (cdef == null &&
1659 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1660 log.error(tree.pos(), "abstract.cant.be.instantiated",
1661 clazztype.tsym);
1662 } else if (cdef != null && clazztype.tsym.isInterface()) {
1663 // Check that no constructor arguments are given to
1664 // anonymous classes implementing an interface
1665 if (!argtypes.isEmpty())
1666 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1668 if (!typeargtypes.isEmpty())
1669 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1671 // Error recovery: pretend no arguments were supplied.
1672 argtypes = List.nil();
1673 typeargtypes = List.nil();
1674 }
1676 // Resolve the called constructor under the assumption
1677 // that we are referring to a superclass instance of the
1678 // current instance (JLS ???).
1679 else {
1680 localEnv.info.selectSuper = cdef != null;
1681 localEnv.info.varArgs = false;
1682 tree.constructor = rs.resolveConstructor(
1683 tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
1684 tree.constructorType = tree.constructor.type.isErroneous() ?
1685 syms.errType :
1686 checkMethod(clazztype,
1687 tree.constructor,
1688 localEnv,
1689 tree.args,
1690 argtypes,
1691 typeargtypes,
1692 localEnv.info.varArgs);
1693 if (localEnv.info.varArgs)
1694 Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
1695 }
1697 if (cdef != null) {
1698 // We are seeing an anonymous class instance creation.
1699 // In this case, the class instance creation
1700 // expression
1701 //
1702 // E.new <typeargs1>C<typargs2>(args) { ... }
1703 //
1704 // is represented internally as
1705 //
1706 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1707 //
1708 // This expression is then *transformed* as follows:
1709 //
1710 // (1) add a STATIC flag to the class definition
1711 // if the current environment is static
1712 // (2) add an extends or implements clause
1713 // (3) add a constructor.
1714 //
1715 // For instance, if C is a class, and ET is the type of E,
1716 // the expression
1717 //
1718 // E.new <typeargs1>C<typargs2>(args) { ... }
1719 //
1720 // is translated to (where X is a fresh name and typarams is the
1721 // parameter list of the super constructor):
1722 //
1723 // new <typeargs1>X(<*nullchk*>E, args) where
1724 // X extends C<typargs2> {
1725 // <typarams> X(ET e, args) {
1726 // e.<typeargs1>super(args)
1727 // }
1728 // ...
1729 // }
1730 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1732 if (clazztype.tsym.isInterface()) {
1733 cdef.implementing = List.of(clazz);
1734 } else {
1735 cdef.extending = clazz;
1736 }
1738 attribStat(cdef, localEnv);
1740 // If an outer instance is given,
1741 // prefix it to the constructor arguments
1742 // and delete it from the new expression
1743 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1744 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1745 argtypes = argtypes.prepend(tree.encl.type);
1746 tree.encl = null;
1747 }
1749 // Reassign clazztype and recompute constructor.
1750 clazztype = cdef.sym.type;
1751 Symbol sym = rs.resolveConstructor(
1752 tree.pos(), localEnv, clazztype, argtypes,
1753 typeargtypes, true, tree.varargsElement != null);
1754 Assert.check(sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous());
1755 tree.constructor = sym;
1756 if (tree.constructor.kind > ERRONEOUS) {
1757 tree.constructorType = syms.errType;
1758 }
1759 else {
1760 tree.constructorType = checkMethod(clazztype,
1761 tree.constructor,
1762 localEnv,
1763 tree.args,
1764 argtypes,
1765 typeargtypes,
1766 localEnv.info.varArgs);
1767 }
1768 }
1770 if (tree.constructor != null && tree.constructor.kind == MTH)
1771 owntype = clazztype;
1772 }
1773 result = check(tree, owntype, VAL, pkind, pt);
1774 chk.validate(tree.typeargs, localEnv);
1775 }
1777 Type attribDiamond(Env<AttrContext> env,
1778 JCNewClass tree,
1779 Type clazztype,
1780 Pair<Scope, Scope> mapping,
1781 List<Type> argtypes,
1782 List<Type> typeargtypes) {
1783 if (clazztype.isErroneous() || mapping == erroneousMapping) {
1784 //if the type of the instance creation expression is erroneous,
1785 //or something prevented us to form a valid mapping, return the
1786 //(possibly erroneous) type unchanged
1787 return clazztype;
1788 }
1789 else if (clazztype.isInterface()) {
1790 //if the type of the instance creation expression is an interface
1791 //skip the method resolution step (JLS 15.12.2.7). The type to be
1792 //inferred is of the kind <X1,X2, ... Xn>C<X1,X2, ... Xn>
1793 clazztype = new ForAll(clazztype.tsym.type.allparams(), clazztype.tsym.type) {
1794 @Override
1795 public List<Type> getConstraints(TypeVar tv, ConstraintKind ck) {
1796 switch (ck) {
1797 case EXTENDS: return types.getBounds(tv);
1798 default: return List.nil();
1799 }
1800 }
1801 @Override
1802 public Type inst(List<Type> inferred, Types types) throws Infer.NoInstanceException {
1803 // check that inferred bounds conform to their bounds
1804 infer.checkWithinBounds(tvars,
1805 types.subst(tvars, tvars, inferred), Warner.noWarnings);
1806 return super.inst(inferred, types);
1807 }
1808 };
1809 } else {
1810 //if the type of the instance creation expression is a class type
1811 //apply method resolution inference (JLS 15.12.2.7). The return type
1812 //of the resolved constructor will be a partially instantiated type
1813 ((ClassSymbol) clazztype.tsym).members_field = mapping.snd;
1814 Symbol constructor;
1815 try {
1816 constructor = rs.resolveDiamond(tree.pos(),
1817 env,
1818 clazztype.tsym.type,
1819 argtypes,
1820 typeargtypes);
1821 } finally {
1822 ((ClassSymbol) clazztype.tsym).members_field = mapping.fst;
1823 }
1824 if (constructor.kind == MTH) {
1825 ClassType ct = new ClassType(clazztype.getEnclosingType(),
1826 clazztype.tsym.type.getTypeArguments(),
1827 clazztype.tsym);
1828 clazztype = checkMethod(ct,
1829 constructor,
1830 env,
1831 tree.args,
1832 argtypes,
1833 typeargtypes,
1834 env.info.varArgs).getReturnType();
1835 } else {
1836 clazztype = syms.errType;
1837 }
1838 }
1839 if (clazztype.tag == FORALL && !pt.isErroneous()) {
1840 //if the resolved constructor's return type has some uninferred
1841 //type-variables, infer them using the expected type and declared
1842 //bounds (JLS 15.12.2.8).
1843 try {
1844 clazztype = infer.instantiateExpr((ForAll) clazztype,
1845 pt.tag == NONE ? syms.objectType : pt,
1846 Warner.noWarnings);
1847 } catch (Infer.InferenceException ex) {
1848 //an error occurred while inferring uninstantiated type-variables
1849 log.error(tree.clazz.pos(),
1850 "cant.apply.diamond.1",
1851 diags.fragment("diamond", clazztype.tsym),
1852 ex.diagnostic);
1853 }
1854 }
1855 clazztype = chk.checkClassType(tree.clazz.pos(),
1856 clazztype,
1857 true);
1858 if (clazztype.tag == CLASS) {
1859 List<Type> invalidDiamondArgs = chk.checkDiamond((ClassType)clazztype);
1860 if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
1861 //one or more types inferred in the previous steps is either a
1862 //captured type or an intersection type --- we need to report an error.
1863 String subkey = invalidDiamondArgs.size() > 1 ?
1864 "diamond.invalid.args" :
1865 "diamond.invalid.arg";
1866 //The error message is of the kind:
1867 //
1868 //cannot infer type arguments for {clazztype}<>;
1869 //reason: {subkey}
1870 //
1871 //where subkey is a fragment of the kind:
1872 //
1873 //type argument(s) {invalidDiamondArgs} inferred for {clazztype}<> is not allowed in this context
1874 log.error(tree.clazz.pos(),
1875 "cant.apply.diamond.1",
1876 diags.fragment("diamond", clazztype.tsym),
1877 diags.fragment(subkey,
1878 invalidDiamondArgs,
1879 diags.fragment("diamond", clazztype.tsym)));
1880 }
1881 }
1882 return clazztype;
1883 }
1885 /** Creates a synthetic scope containing fake generic constructors.
1886 * Assuming that the original scope contains a constructor of the kind:
1887 * Foo(X x, Y y), where X,Y are class type-variables declared in Foo,
1888 * the synthetic scope is added a generic constructor of the kind:
1889 * <X,Y>Foo<X,Y>(X x, Y y). This is crucial in order to enable diamond
1890 * inference. The inferred return type of the synthetic constructor IS
1891 * the inferred type for the diamond operator.
1892 */
1893 private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype, boolean overrideProtectedAccess) {
1894 if (ctype.tag != CLASS) {
1895 return erroneousMapping;
1896 }
1897 Pair<Scope, Scope> mapping =
1898 new Pair<Scope, Scope>(ctype.tsym.members(), new Scope(ctype.tsym));
1899 List<Type> typevars = ctype.tsym.type.getTypeArguments();
1900 for (Scope.Entry e = mapping.fst.lookup(names.init);
1901 e.scope != null;
1902 e = e.next()) {
1903 MethodSymbol newConstr = (MethodSymbol) e.sym.clone(ctype.tsym);
1904 if (overrideProtectedAccess && (newConstr.flags() & PROTECTED) != 0) {
1905 //make protected constructor public (this is required for
1906 //anonymous inner class creation expressions using diamond)
1907 newConstr.flags_field |= PUBLIC;
1908 newConstr.flags_field &= ~PROTECTED;
1909 }
1910 newConstr.name = names.init;
1911 List<Type> oldTypeargs = List.nil();
1912 if (newConstr.type.tag == FORALL) {
1913 oldTypeargs = ((ForAll) newConstr.type).tvars;
1914 }
1915 newConstr.type = new MethodType(newConstr.type.getParameterTypes(),
1916 new ClassType(ctype.getEnclosingType(), ctype.tsym.type.getTypeArguments(), ctype.tsym),
1917 newConstr.type.getThrownTypes(),
1918 syms.methodClass);
1919 newConstr.type = new ForAll(typevars.prependList(oldTypeargs), newConstr.type);
1920 mapping.snd.enter(newConstr);
1921 }
1922 return mapping;
1923 }
1925 private final Pair<Scope,Scope> erroneousMapping = new Pair<Scope,Scope>(null, null);
1927 /** Make an attributed null check tree.
1928 */
1929 public JCExpression makeNullCheck(JCExpression arg) {
1930 // optimization: X.this is never null; skip null check
1931 Name name = TreeInfo.name(arg);
1932 if (name == names._this || name == names._super) return arg;
1934 int optag = JCTree.NULLCHK;
1935 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1936 tree.operator = syms.nullcheck;
1937 tree.type = arg.type;
1938 return tree;
1939 }
1941 public void visitNewArray(JCNewArray tree) {
1942 Type owntype = types.createErrorType(tree.type);
1943 Type elemtype;
1944 if (tree.elemtype != null) {
1945 elemtype = attribType(tree.elemtype, env);
1946 chk.validate(tree.elemtype, env);
1947 owntype = elemtype;
1948 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1949 attribExpr(l.head, env, syms.intType);
1950 owntype = new ArrayType(owntype, syms.arrayClass);
1951 }
1952 } else {
1953 // we are seeing an untyped aggregate { ... }
1954 // this is allowed only if the prototype is an array
1955 if (pt.tag == ARRAY) {
1956 elemtype = types.elemtype(pt);
1957 } else {
1958 if (pt.tag != ERROR) {
1959 log.error(tree.pos(), "illegal.initializer.for.type",
1960 pt);
1961 }
1962 elemtype = types.createErrorType(pt);
1963 }
1964 }
1965 if (tree.elems != null) {
1966 attribExprs(tree.elems, env, elemtype);
1967 owntype = new ArrayType(elemtype, syms.arrayClass);
1968 }
1969 if (!types.isReifiable(elemtype))
1970 log.error(tree.pos(), "generic.array.creation");
1971 result = check(tree, owntype, VAL, pkind, pt);
1972 }
1974 public void visitParens(JCParens tree) {
1975 Type owntype = attribTree(tree.expr, env, pkind, pt);
1976 result = check(tree, owntype, pkind, pkind, pt);
1977 Symbol sym = TreeInfo.symbol(tree);
1978 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1979 log.error(tree.pos(), "illegal.start.of.type");
1980 }
1982 public void visitAssign(JCAssign tree) {
1983 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1984 Type capturedType = capture(owntype);
1985 attribExpr(tree.rhs, env, owntype);
1986 result = check(tree, capturedType, VAL, pkind, pt);
1987 }
1989 public void visitAssignop(JCAssignOp tree) {
1990 // Attribute arguments.
1991 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
1992 Type operand = attribExpr(tree.rhs, env);
1993 // Find operator.
1994 Symbol operator = tree.operator = rs.resolveBinaryOperator(
1995 tree.pos(), tree.getTag() - JCTree.ASGOffset, env,
1996 owntype, operand);
1998 if (operator.kind == MTH &&
1999 !owntype.isErroneous() &&
2000 !operand.isErroneous()) {
2001 chk.checkOperator(tree.pos(),
2002 (OperatorSymbol)operator,
2003 tree.getTag() - JCTree.ASGOffset,
2004 owntype,
2005 operand);
2006 chk.checkDivZero(tree.rhs.pos(), operator, operand);
2007 chk.checkCastable(tree.rhs.pos(),
2008 operator.type.getReturnType(),
2009 owntype);
2010 }
2011 result = check(tree, owntype, VAL, pkind, pt);
2012 }
2014 public void visitUnary(JCUnary tree) {
2015 // Attribute arguments.
2016 Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
2017 ? attribTree(tree.arg, env, VAR, Type.noType)
2018 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
2020 // Find operator.
2021 Symbol operator = tree.operator =
2022 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
2024 Type owntype = types.createErrorType(tree.type);
2025 if (operator.kind == MTH &&
2026 !argtype.isErroneous()) {
2027 owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
2028 ? tree.arg.type
2029 : operator.type.getReturnType();
2030 int opc = ((OperatorSymbol)operator).opcode;
2032 // If the argument is constant, fold it.
2033 if (argtype.constValue() != null) {
2034 Type ctype = cfolder.fold1(opc, argtype);
2035 if (ctype != null) {
2036 owntype = cfolder.coerce(ctype, owntype);
2038 // Remove constant types from arguments to
2039 // conserve space. The parser will fold concatenations
2040 // of string literals; the code here also
2041 // gets rid of intermediate results when some of the
2042 // operands are constant identifiers.
2043 if (tree.arg.type.tsym == syms.stringType.tsym) {
2044 tree.arg.type = syms.stringType;
2045 }
2046 }
2047 }
2048 }
2049 result = check(tree, owntype, VAL, pkind, pt);
2050 }
2052 public void visitBinary(JCBinary tree) {
2053 // Attribute arguments.
2054 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
2055 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
2057 // Find operator.
2058 Symbol operator = tree.operator =
2059 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
2061 Type owntype = types.createErrorType(tree.type);
2062 if (operator.kind == MTH &&
2063 !left.isErroneous() &&
2064 !right.isErroneous()) {
2065 owntype = operator.type.getReturnType();
2066 int opc = chk.checkOperator(tree.lhs.pos(),
2067 (OperatorSymbol)operator,
2068 tree.getTag(),
2069 left,
2070 right);
2072 // If both arguments are constants, fold them.
2073 if (left.constValue() != null && right.constValue() != null) {
2074 Type ctype = cfolder.fold2(opc, left, right);
2075 if (ctype != null) {
2076 owntype = cfolder.coerce(ctype, owntype);
2078 // Remove constant types from arguments to
2079 // conserve space. The parser will fold concatenations
2080 // of string literals; the code here also
2081 // gets rid of intermediate results when some of the
2082 // operands are constant identifiers.
2083 if (tree.lhs.type.tsym == syms.stringType.tsym) {
2084 tree.lhs.type = syms.stringType;
2085 }
2086 if (tree.rhs.type.tsym == syms.stringType.tsym) {
2087 tree.rhs.type = syms.stringType;
2088 }
2089 }
2090 }
2092 // Check that argument types of a reference ==, != are
2093 // castable to each other, (JLS???).
2094 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
2095 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
2096 log.error(tree.pos(), "incomparable.types", left, right);
2097 }
2098 }
2100 chk.checkDivZero(tree.rhs.pos(), operator, right);
2101 }
2102 result = check(tree, owntype, VAL, pkind, pt);
2103 }
2105 public void visitTypeCast(JCTypeCast tree) {
2106 Type clazztype = attribType(tree.clazz, env);
2107 chk.validate(tree.clazz, env, false);
2108 //a fresh environment is required for 292 inference to work properly ---
2109 //see Infer.instantiatePolymorphicSignatureInstance()
2110 Env<AttrContext> localEnv = env.dup(tree);
2111 Type exprtype = attribExpr(tree.expr, localEnv, Infer.anyPoly);
2112 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2113 if (exprtype.constValue() != null)
2114 owntype = cfolder.coerce(exprtype, owntype);
2115 result = check(tree, capture(owntype), VAL, pkind, pt);
2116 }
2118 public void visitTypeTest(JCInstanceOf tree) {
2119 Type exprtype = chk.checkNullOrRefType(
2120 tree.expr.pos(), attribExpr(tree.expr, env));
2121 Type clazztype = chk.checkReifiableReferenceType(
2122 tree.clazz.pos(), attribType(tree.clazz, env));
2123 chk.validate(tree.clazz, env, false);
2124 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2125 result = check(tree, syms.booleanType, VAL, pkind, pt);
2126 }
2128 public void visitIndexed(JCArrayAccess tree) {
2129 Type owntype = types.createErrorType(tree.type);
2130 Type atype = attribExpr(tree.indexed, env);
2131 attribExpr(tree.index, env, syms.intType);
2132 if (types.isArray(atype))
2133 owntype = types.elemtype(atype);
2134 else if (atype.tag != ERROR)
2135 log.error(tree.pos(), "array.req.but.found", atype);
2136 if ((pkind & VAR) == 0) owntype = capture(owntype);
2137 result = check(tree, owntype, VAR, pkind, pt);
2138 }
2140 public void visitIdent(JCIdent tree) {
2141 Symbol sym;
2142 boolean varArgs = false;
2144 // Find symbol
2145 if (pt.tag == METHOD || pt.tag == FORALL) {
2146 // If we are looking for a method, the prototype `pt' will be a
2147 // method type with the type of the call's arguments as parameters.
2148 env.info.varArgs = false;
2149 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
2150 varArgs = env.info.varArgs;
2151 } else if (tree.sym != null && tree.sym.kind != VAR) {
2152 sym = tree.sym;
2153 } else {
2154 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
2155 }
2156 tree.sym = sym;
2158 // (1) Also find the environment current for the class where
2159 // sym is defined (`symEnv').
2160 // Only for pre-tiger versions (1.4 and earlier):
2161 // (2) Also determine whether we access symbol out of an anonymous
2162 // class in a this or super call. This is illegal for instance
2163 // members since such classes don't carry a this$n link.
2164 // (`noOuterThisPath').
2165 Env<AttrContext> symEnv = env;
2166 boolean noOuterThisPath = false;
2167 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
2168 (sym.kind & (VAR | MTH | TYP)) != 0 &&
2169 sym.owner.kind == TYP &&
2170 tree.name != names._this && tree.name != names._super) {
2172 // Find environment in which identifier is defined.
2173 while (symEnv.outer != null &&
2174 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
2175 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
2176 noOuterThisPath = !allowAnonOuterThis;
2177 symEnv = symEnv.outer;
2178 }
2179 }
2181 // If symbol is a variable, ...
2182 if (sym.kind == VAR) {
2183 VarSymbol v = (VarSymbol)sym;
2185 // ..., evaluate its initializer, if it has one, and check for
2186 // illegal forward reference.
2187 checkInit(tree, env, v, false);
2189 // If symbol is a local variable accessed from an embedded
2190 // inner class check that it is final.
2191 if (v.owner.kind == MTH &&
2192 v.owner != env.info.scope.owner &&
2193 (v.flags_field & FINAL) == 0) {
2194 log.error(tree.pos(),
2195 "local.var.accessed.from.icls.needs.final",
2196 v);
2197 }
2199 // If we are expecting a variable (as opposed to a value), check
2200 // that the variable is assignable in the current environment.
2201 if (pkind == VAR)
2202 checkAssignable(tree.pos(), v, null, env);
2203 }
2205 // In a constructor body,
2206 // if symbol is a field or instance method, check that it is
2207 // not accessed before the supertype constructor is called.
2208 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
2209 (sym.kind & (VAR | MTH)) != 0 &&
2210 sym.owner.kind == TYP &&
2211 (sym.flags() & STATIC) == 0) {
2212 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
2213 }
2214 Env<AttrContext> env1 = env;
2215 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
2216 // If the found symbol is inaccessible, then it is
2217 // accessed through an enclosing instance. Locate this
2218 // enclosing instance:
2219 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
2220 env1 = env1.outer;
2221 }
2222 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
2223 }
2225 public void visitSelect(JCFieldAccess tree) {
2226 // Determine the expected kind of the qualifier expression.
2227 int skind = 0;
2228 if (tree.name == names._this || tree.name == names._super ||
2229 tree.name == names._class)
2230 {
2231 skind = TYP;
2232 } else {
2233 if ((pkind & PCK) != 0) skind = skind | PCK;
2234 if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
2235 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
2236 }
2238 // Attribute the qualifier expression, and determine its symbol (if any).
2239 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
2240 if ((pkind & (PCK | TYP)) == 0)
2241 site = capture(site); // Capture field access
2243 // don't allow T.class T[].class, etc
2244 if (skind == TYP) {
2245 Type elt = site;
2246 while (elt.tag == ARRAY)
2247 elt = ((ArrayType)elt).elemtype;
2248 if (elt.tag == TYPEVAR) {
2249 log.error(tree.pos(), "type.var.cant.be.deref");
2250 result = types.createErrorType(tree.type);
2251 return;
2252 }
2253 }
2255 // If qualifier symbol is a type or `super', assert `selectSuper'
2256 // for the selection. This is relevant for determining whether
2257 // protected symbols are accessible.
2258 Symbol sitesym = TreeInfo.symbol(tree.selected);
2259 boolean selectSuperPrev = env.info.selectSuper;
2260 env.info.selectSuper =
2261 sitesym != null &&
2262 sitesym.name == names._super;
2264 // If selected expression is polymorphic, strip
2265 // type parameters and remember in env.info.tvars, so that
2266 // they can be added later (in Attr.checkId and Infer.instantiateMethod).
2267 if (tree.selected.type.tag == FORALL) {
2268 ForAll pstype = (ForAll)tree.selected.type;
2269 env.info.tvars = pstype.tvars;
2270 site = tree.selected.type = pstype.qtype;
2271 }
2273 // Determine the symbol represented by the selection.
2274 env.info.varArgs = false;
2275 Symbol sym = selectSym(tree, sitesym, site, env, pt, pkind);
2276 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
2277 site = capture(site);
2278 sym = selectSym(tree, sitesym, site, env, pt, pkind);
2279 }
2280 boolean varArgs = env.info.varArgs;
2281 tree.sym = sym;
2283 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
2284 while (site.tag == TYPEVAR) site = site.getUpperBound();
2285 site = capture(site);
2286 }
2288 // If that symbol is a variable, ...
2289 if (sym.kind == VAR) {
2290 VarSymbol v = (VarSymbol)sym;
2292 // ..., evaluate its initializer, if it has one, and check for
2293 // illegal forward reference.
2294 checkInit(tree, env, v, true);
2296 // If we are expecting a variable (as opposed to a value), check
2297 // that the variable is assignable in the current environment.
2298 if (pkind == VAR)
2299 checkAssignable(tree.pos(), v, tree.selected, env);
2300 }
2302 if (sitesym != null &&
2303 sitesym.kind == VAR &&
2304 ((VarSymbol)sitesym).isResourceVariable() &&
2305 sym.kind == MTH &&
2306 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
2307 env.info.lint.isEnabled(LintCategory.TRY)) {
2308 log.warning(LintCategory.TRY, tree, "try.explicit.close.call");
2309 }
2311 // Disallow selecting a type from an expression
2312 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
2313 tree.type = check(tree.selected, pt,
2314 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
2315 }
2317 if (isType(sitesym)) {
2318 if (sym.name == names._this) {
2319 // If `C' is the currently compiled class, check that
2320 // C.this' does not appear in a call to a super(...)
2321 if (env.info.isSelfCall &&
2322 site.tsym == env.enclClass.sym) {
2323 chk.earlyRefError(tree.pos(), sym);
2324 }
2325 } else {
2326 // Check if type-qualified fields or methods are static (JLS)
2327 if ((sym.flags() & STATIC) == 0 &&
2328 sym.name != names._super &&
2329 (sym.kind == VAR || sym.kind == MTH)) {
2330 rs.access(rs.new StaticError(sym),
2331 tree.pos(), site, sym.name, true);
2332 }
2333 }
2334 } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
2335 // If the qualified item is not a type and the selected item is static, report
2336 // a warning. Make allowance for the class of an array type e.g. Object[].class)
2337 chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
2338 }
2340 // If we are selecting an instance member via a `super', ...
2341 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
2343 // Check that super-qualified symbols are not abstract (JLS)
2344 rs.checkNonAbstract(tree.pos(), sym);
2346 if (site.isRaw()) {
2347 // Determine argument types for site.
2348 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
2349 if (site1 != null) site = site1;
2350 }
2351 }
2353 env.info.selectSuper = selectSuperPrev;
2354 result = checkId(tree, site, sym, env, pkind, pt, varArgs);
2355 env.info.tvars = List.nil();
2356 }
2357 //where
2358 /** Determine symbol referenced by a Select expression,
2359 *
2360 * @param tree The select tree.
2361 * @param site The type of the selected expression,
2362 * @param env The current environment.
2363 * @param pt The current prototype.
2364 * @param pkind The expected kind(s) of the Select expression.
2365 */
2366 private Symbol selectSym(JCFieldAccess tree,
2367 Type site,
2368 Env<AttrContext> env,
2369 Type pt,
2370 int pkind) {
2371 return selectSym(tree, site.tsym, site, env, pt, pkind);
2372 }
2373 private Symbol selectSym(JCFieldAccess tree,
2374 Symbol location,
2375 Type site,
2376 Env<AttrContext> env,
2377 Type pt,
2378 int pkind) {
2379 DiagnosticPosition pos = tree.pos();
2380 Name name = tree.name;
2381 switch (site.tag) {
2382 case PACKAGE:
2383 return rs.access(
2384 rs.findIdentInPackage(env, site.tsym, name, pkind),
2385 pos, location, site, name, true);
2386 case ARRAY:
2387 case CLASS:
2388 if (pt.tag == METHOD || pt.tag == FORALL) {
2389 return rs.resolveQualifiedMethod(
2390 pos, env, location, site, name, pt.getParameterTypes(), pt.getTypeArguments());
2391 } else if (name == names._this || name == names._super) {
2392 return rs.resolveSelf(pos, env, site.tsym, name);
2393 } else if (name == names._class) {
2394 // In this case, we have already made sure in
2395 // visitSelect that qualifier expression is a type.
2396 Type t = syms.classType;
2397 List<Type> typeargs = allowGenerics
2398 ? List.of(types.erasure(site))
2399 : List.<Type>nil();
2400 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
2401 return new VarSymbol(
2402 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2403 } else {
2404 // We are seeing a plain identifier as selector.
2405 Symbol sym = rs.findIdentInType(env, site, name, pkind);
2406 if ((pkind & ERRONEOUS) == 0)
2407 sym = rs.access(sym, pos, location, site, name, true);
2408 return sym;
2409 }
2410 case WILDCARD:
2411 throw new AssertionError(tree);
2412 case TYPEVAR:
2413 // Normally, site.getUpperBound() shouldn't be null.
2414 // It should only happen during memberEnter/attribBase
2415 // when determining the super type which *must* beac
2416 // done before attributing the type variables. In
2417 // other words, we are seeing this illegal program:
2418 // class B<T> extends A<T.foo> {}
2419 Symbol sym = (site.getUpperBound() != null)
2420 ? selectSym(tree, location, capture(site.getUpperBound()), env, pt, pkind)
2421 : null;
2422 if (sym == null) {
2423 log.error(pos, "type.var.cant.be.deref");
2424 return syms.errSymbol;
2425 } else {
2426 Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
2427 rs.new AccessError(env, site, sym) :
2428 sym;
2429 rs.access(sym2, pos, location, site, name, true);
2430 return sym;
2431 }
2432 case ERROR:
2433 // preserve identifier names through errors
2434 return types.createErrorType(name, site.tsym, site).tsym;
2435 default:
2436 // The qualifier expression is of a primitive type -- only
2437 // .class is allowed for these.
2438 if (name == names._class) {
2439 // In this case, we have already made sure in Select that
2440 // qualifier expression is a type.
2441 Type t = syms.classType;
2442 Type arg = types.boxedClass(site).type;
2443 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2444 return new VarSymbol(
2445 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2446 } else {
2447 log.error(pos, "cant.deref", site);
2448 return syms.errSymbol;
2449 }
2450 }
2451 }
2453 /** Determine type of identifier or select expression and check that
2454 * (1) the referenced symbol is not deprecated
2455 * (2) the symbol's type is safe (@see checkSafe)
2456 * (3) if symbol is a variable, check that its type and kind are
2457 * compatible with the prototype and protokind.
2458 * (4) if symbol is an instance field of a raw type,
2459 * which is being assigned to, issue an unchecked warning if its
2460 * type changes under erasure.
2461 * (5) if symbol is an instance method of a raw type, issue an
2462 * unchecked warning if its argument types change under erasure.
2463 * If checks succeed:
2464 * If symbol is a constant, return its constant type
2465 * else if symbol is a method, return its result type
2466 * otherwise return its type.
2467 * Otherwise return errType.
2468 *
2469 * @param tree The syntax tree representing the identifier
2470 * @param site If this is a select, the type of the selected
2471 * expression, otherwise the type of the current class.
2472 * @param sym The symbol representing the identifier.
2473 * @param env The current environment.
2474 * @param pkind The set of expected kinds.
2475 * @param pt The expected type.
2476 */
2477 Type checkId(JCTree tree,
2478 Type site,
2479 Symbol sym,
2480 Env<AttrContext> env,
2481 int pkind,
2482 Type pt,
2483 boolean useVarargs) {
2484 if (pt.isErroneous()) return types.createErrorType(site);
2485 Type owntype; // The computed type of this identifier occurrence.
2486 switch (sym.kind) {
2487 case TYP:
2488 // For types, the computed type equals the symbol's type,
2489 // except for two situations:
2490 owntype = sym.type;
2491 if (owntype.tag == CLASS) {
2492 Type ownOuter = owntype.getEnclosingType();
2494 // (a) If the symbol's type is parameterized, erase it
2495 // because no type parameters were given.
2496 // We recover generic outer type later in visitTypeApply.
2497 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2498 owntype = types.erasure(owntype);
2499 }
2501 // (b) If the symbol's type is an inner class, then
2502 // we have to interpret its outer type as a superclass
2503 // of the site type. Example:
2504 //
2505 // class Tree<A> { class Visitor { ... } }
2506 // class PointTree extends Tree<Point> { ... }
2507 // ...PointTree.Visitor...
2508 //
2509 // Then the type of the last expression above is
2510 // Tree<Point>.Visitor.
2511 else if (ownOuter.tag == CLASS && site != ownOuter) {
2512 Type normOuter = site;
2513 if (normOuter.tag == CLASS)
2514 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2515 if (normOuter == null) // perhaps from an import
2516 normOuter = types.erasure(ownOuter);
2517 if (normOuter != ownOuter)
2518 owntype = new ClassType(
2519 normOuter, List.<Type>nil(), owntype.tsym);
2520 }
2521 }
2522 break;
2523 case VAR:
2524 VarSymbol v = (VarSymbol)sym;
2525 // Test (4): if symbol is an instance field of a raw type,
2526 // which is being assigned to, issue an unchecked warning if
2527 // its type changes under erasure.
2528 if (allowGenerics &&
2529 pkind == VAR &&
2530 v.owner.kind == TYP &&
2531 (v.flags() & STATIC) == 0 &&
2532 (site.tag == CLASS || site.tag == TYPEVAR)) {
2533 Type s = types.asOuterSuper(site, v.owner);
2534 if (s != null &&
2535 s.isRaw() &&
2536 !types.isSameType(v.type, v.erasure(types))) {
2537 chk.warnUnchecked(tree.pos(),
2538 "unchecked.assign.to.var",
2539 v, s);
2540 }
2541 }
2542 // The computed type of a variable is the type of the
2543 // variable symbol, taken as a member of the site type.
2544 owntype = (sym.owner.kind == TYP &&
2545 sym.name != names._this && sym.name != names._super)
2546 ? types.memberType(site, sym)
2547 : sym.type;
2549 if (env.info.tvars.nonEmpty()) {
2550 Type owntype1 = new ForAll(env.info.tvars, owntype);
2551 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2552 if (!owntype.contains(l.head)) {
2553 log.error(tree.pos(), "undetermined.type", owntype1);
2554 owntype1 = types.createErrorType(owntype1);
2555 }
2556 owntype = owntype1;
2557 }
2559 // If the variable is a constant, record constant value in
2560 // computed type.
2561 if (v.getConstValue() != null && isStaticReference(tree))
2562 owntype = owntype.constType(v.getConstValue());
2564 if (pkind == VAL) {
2565 owntype = capture(owntype); // capture "names as expressions"
2566 }
2567 break;
2568 case MTH: {
2569 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2570 owntype = checkMethod(site, sym, env, app.args,
2571 pt.getParameterTypes(), pt.getTypeArguments(),
2572 env.info.varArgs);
2573 break;
2574 }
2575 case PCK: case ERR:
2576 owntype = sym.type;
2577 break;
2578 default:
2579 throw new AssertionError("unexpected kind: " + sym.kind +
2580 " in tree " + tree);
2581 }
2583 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2584 // (for constructors, the error was given when the constructor was
2585 // resolved)
2587 if (sym.name != names.init) {
2588 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
2589 chk.checkSunAPI(tree.pos(), sym);
2590 }
2592 // Test (3): if symbol is a variable, check that its type and
2593 // kind are compatible with the prototype and protokind.
2594 return check(tree, owntype, sym.kind, pkind, pt);
2595 }
2597 /** Check that variable is initialized and evaluate the variable's
2598 * initializer, if not yet done. Also check that variable is not
2599 * referenced before it is defined.
2600 * @param tree The tree making up the variable reference.
2601 * @param env The current environment.
2602 * @param v The variable's symbol.
2603 */
2604 private void checkInit(JCTree tree,
2605 Env<AttrContext> env,
2606 VarSymbol v,
2607 boolean onlyWarning) {
2608 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2609 // tree.pos + " " + v.pos + " " +
2610 // Resolve.isStatic(env));//DEBUG
2612 // A forward reference is diagnosed if the declaration position
2613 // of the variable is greater than the current tree position
2614 // and the tree and variable definition occur in the same class
2615 // definition. Note that writes don't count as references.
2616 // This check applies only to class and instance
2617 // variables. Local variables follow different scope rules,
2618 // and are subject to definite assignment checking.
2619 if ((env.info.enclVar == v || v.pos > tree.pos) &&
2620 v.owner.kind == TYP &&
2621 canOwnInitializer(env.info.scope.owner) &&
2622 v.owner == env.info.scope.owner.enclClass() &&
2623 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2624 (env.tree.getTag() != JCTree.ASSIGN ||
2625 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2626 String suffix = (env.info.enclVar == v) ?
2627 "self.ref" : "forward.ref";
2628 if (!onlyWarning || isStaticEnumField(v)) {
2629 log.error(tree.pos(), "illegal." + suffix);
2630 } else if (useBeforeDeclarationWarning) {
2631 log.warning(tree.pos(), suffix, v);
2632 }
2633 }
2635 v.getConstValue(); // ensure initializer is evaluated
2637 checkEnumInitializer(tree, env, v);
2638 }
2640 /**
2641 * Check for illegal references to static members of enum. In
2642 * an enum type, constructors and initializers may not
2643 * reference its static members unless they are constant.
2644 *
2645 * @param tree The tree making up the variable reference.
2646 * @param env The current environment.
2647 * @param v The variable's symbol.
2648 * @see JLS 3rd Ed. (8.9 Enums)
2649 */
2650 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2651 // JLS 3rd Ed.:
2652 //
2653 // "It is a compile-time error to reference a static field
2654 // of an enum type that is not a compile-time constant
2655 // (15.28) from constructors, instance initializer blocks,
2656 // or instance variable initializer expressions of that
2657 // type. It is a compile-time error for the constructors,
2658 // instance initializer blocks, or instance variable
2659 // initializer expressions of an enum constant e to refer
2660 // to itself or to an enum constant of the same type that
2661 // is declared to the right of e."
2662 if (isStaticEnumField(v)) {
2663 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2665 if (enclClass == null || enclClass.owner == null)
2666 return;
2668 // See if the enclosing class is the enum (or a
2669 // subclass thereof) declaring v. If not, this
2670 // reference is OK.
2671 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2672 return;
2674 // If the reference isn't from an initializer, then
2675 // the reference is OK.
2676 if (!Resolve.isInitializer(env))
2677 return;
2679 log.error(tree.pos(), "illegal.enum.static.ref");
2680 }
2681 }
2683 /** Is the given symbol a static, non-constant field of an Enum?
2684 * Note: enum literals should not be regarded as such
2685 */
2686 private boolean isStaticEnumField(VarSymbol v) {
2687 return Flags.isEnum(v.owner) &&
2688 Flags.isStatic(v) &&
2689 !Flags.isConstant(v) &&
2690 v.name != names._class;
2691 }
2693 /** Can the given symbol be the owner of code which forms part
2694 * if class initialization? This is the case if the symbol is
2695 * a type or field, or if the symbol is the synthetic method.
2696 * owning a block.
2697 */
2698 private boolean canOwnInitializer(Symbol sym) {
2699 return
2700 (sym.kind & (VAR | TYP)) != 0 ||
2701 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2702 }
2704 Warner noteWarner = new Warner();
2706 /**
2707 * Check that method arguments conform to its instantation.
2708 **/
2709 public Type checkMethod(Type site,
2710 Symbol sym,
2711 Env<AttrContext> env,
2712 final List<JCExpression> argtrees,
2713 List<Type> argtypes,
2714 List<Type> typeargtypes,
2715 boolean useVarargs) {
2716 // Test (5): if symbol is an instance method of a raw type, issue
2717 // an unchecked warning if its argument types change under erasure.
2718 if (allowGenerics &&
2719 (sym.flags() & STATIC) == 0 &&
2720 (site.tag == CLASS || site.tag == TYPEVAR)) {
2721 Type s = types.asOuterSuper(site, sym.owner);
2722 if (s != null && s.isRaw() &&
2723 !types.isSameTypes(sym.type.getParameterTypes(),
2724 sym.erasure(types).getParameterTypes())) {
2725 chk.warnUnchecked(env.tree.pos(),
2726 "unchecked.call.mbr.of.raw.type",
2727 sym, s);
2728 }
2729 }
2731 // Compute the identifier's instantiated type.
2732 // For methods, we need to compute the instance type by
2733 // Resolve.instantiate from the symbol's type as well as
2734 // any type arguments and value arguments.
2735 noteWarner.clear();
2736 Type owntype = rs.instantiate(env,
2737 site,
2738 sym,
2739 argtypes,
2740 typeargtypes,
2741 true,
2742 useVarargs,
2743 noteWarner);
2744 boolean warned = noteWarner.hasNonSilentLint(LintCategory.UNCHECKED);
2746 // If this fails, something went wrong; we should not have
2747 // found the identifier in the first place.
2748 if (owntype == null) {
2749 if (!pt.isErroneous())
2750 log.error(env.tree.pos(),
2751 "internal.error.cant.instantiate",
2752 sym, site,
2753 Type.toString(pt.getParameterTypes()));
2754 owntype = types.createErrorType(site);
2755 } else {
2756 // System.out.println("call : " + env.tree);
2757 // System.out.println("method : " + owntype);
2758 // System.out.println("actuals: " + argtypes);
2759 List<Type> formals = owntype.getParameterTypes();
2760 Type last = useVarargs ? formals.last() : null;
2761 if (sym.name==names.init &&
2762 sym.owner == syms.enumSym)
2763 formals = formals.tail.tail;
2764 List<JCExpression> args = argtrees;
2765 while (formals.head != last) {
2766 JCTree arg = args.head;
2767 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2768 assertConvertible(arg, arg.type, formals.head, warn);
2769 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED);
2770 args = args.tail;
2771 formals = formals.tail;
2772 }
2773 if (useVarargs) {
2774 Type varArg = types.elemtype(last);
2775 while (args.tail != null) {
2776 JCTree arg = args.head;
2777 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2778 assertConvertible(arg, arg.type, varArg, warn);
2779 warned |= warn.hasNonSilentLint(LintCategory.UNCHECKED);
2780 args = args.tail;
2781 }
2782 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2783 // non-varargs call to varargs method
2784 Type varParam = owntype.getParameterTypes().last();
2785 Type lastArg = argtypes.last();
2786 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2787 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2788 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2789 types.elemtype(varParam),
2790 varParam);
2791 }
2793 if (warned && sym.type.tag == FORALL) {
2794 chk.warnUnchecked(env.tree.pos(),
2795 "unchecked.meth.invocation.applied",
2796 kindName(sym),
2797 sym.name,
2798 rs.methodArguments(sym.type.getParameterTypes()),
2799 rs.methodArguments(argtypes),
2800 kindName(sym.location()),
2801 sym.location());
2802 owntype = new MethodType(owntype.getParameterTypes(),
2803 types.erasure(owntype.getReturnType()),
2804 owntype.getThrownTypes(),
2805 syms.methodClass);
2806 }
2807 if (useVarargs) {
2808 JCTree tree = env.tree;
2809 Type argtype = owntype.getParameterTypes().last();
2810 if (owntype.getReturnType().tag != FORALL || warned) {
2811 chk.checkVararg(env.tree.pos(), owntype.getParameterTypes(), sym);
2812 }
2813 Type elemtype = types.elemtype(argtype);
2814 switch (tree.getTag()) {
2815 case JCTree.APPLY:
2816 ((JCMethodInvocation) tree).varargsElement = elemtype;
2817 break;
2818 case JCTree.NEWCLASS:
2819 ((JCNewClass) tree).varargsElement = elemtype;
2820 break;
2821 default:
2822 throw new AssertionError(""+tree);
2823 }
2824 }
2825 }
2826 return owntype;
2827 }
2829 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2830 if (types.isConvertible(actual, formal, warn))
2831 return;
2833 if (formal.isCompound()
2834 && types.isSubtype(actual, types.supertype(formal))
2835 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2836 return;
2838 if (false) {
2839 // TODO: make assertConvertible work
2840 chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal);
2841 throw new AssertionError("Tree: " + tree
2842 + " actual:" + actual
2843 + " formal: " + formal);
2844 }
2845 }
2847 public void visitLiteral(JCLiteral tree) {
2848 result = check(
2849 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2850 }
2851 //where
2852 /** Return the type of a literal with given type tag.
2853 */
2854 Type litType(int tag) {
2855 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2856 }
2858 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2859 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2860 }
2862 public void visitTypeArray(JCArrayTypeTree tree) {
2863 Type etype = attribType(tree.elemtype, env);
2864 Type type = new ArrayType(etype, syms.arrayClass);
2865 result = check(tree, type, TYP, pkind, pt);
2866 }
2868 /** Visitor method for parameterized types.
2869 * Bound checking is left until later, since types are attributed
2870 * before supertype structure is completely known
2871 */
2872 public void visitTypeApply(JCTypeApply tree) {
2873 Type owntype = types.createErrorType(tree.type);
2875 // Attribute functor part of application and make sure it's a class.
2876 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2878 // Attribute type parameters
2879 List<Type> actuals = attribTypes(tree.arguments, env);
2881 if (clazztype.tag == CLASS) {
2882 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2884 if (actuals.length() == formals.length() || actuals.length() == 0) {
2885 List<Type> a = actuals;
2886 List<Type> f = formals;
2887 while (a.nonEmpty()) {
2888 a.head = a.head.withTypeVar(f.head);
2889 a = a.tail;
2890 f = f.tail;
2891 }
2892 // Compute the proper generic outer
2893 Type clazzOuter = clazztype.getEnclosingType();
2894 if (clazzOuter.tag == CLASS) {
2895 Type site;
2896 JCExpression clazz = TreeInfo.typeIn(tree.clazz);
2897 if (clazz.getTag() == JCTree.IDENT) {
2898 site = env.enclClass.sym.type;
2899 } else if (clazz.getTag() == JCTree.SELECT) {
2900 site = ((JCFieldAccess) clazz).selected.type;
2901 } else throw new AssertionError(""+tree);
2902 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2903 if (site.tag == CLASS)
2904 site = types.asOuterSuper(site, clazzOuter.tsym);
2905 if (site == null)
2906 site = types.erasure(clazzOuter);
2907 clazzOuter = site;
2908 }
2909 }
2910 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2911 } else {
2912 if (formals.length() != 0) {
2913 log.error(tree.pos(), "wrong.number.type.args",
2914 Integer.toString(formals.length()));
2915 } else {
2916 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2917 }
2918 owntype = types.createErrorType(tree.type);
2919 }
2920 }
2921 result = check(tree, owntype, TYP, pkind, pt);
2922 }
2924 public void visitTypeDisjunction(JCTypeDisjunction tree) {
2925 ListBuffer<Type> multicatchTypes = ListBuffer.lb();
2926 for (JCExpression typeTree : tree.alternatives) {
2927 Type ctype = attribType(typeTree, env);
2928 ctype = chk.checkType(typeTree.pos(),
2929 chk.checkClassType(typeTree.pos(), ctype),
2930 syms.throwableType);
2931 multicatchTypes.append(ctype);
2932 }
2933 tree.type = result = check(tree, types.lub(multicatchTypes.toList()), TYP, pkind, pt);
2934 }
2936 public void visitTypeParameter(JCTypeParameter tree) {
2937 TypeVar a = (TypeVar)tree.type;
2938 Set<Type> boundSet = new HashSet<Type>();
2939 if (a.bound.isErroneous())
2940 return;
2941 List<Type> bs = types.getBounds(a);
2942 if (tree.bounds.nonEmpty()) {
2943 // accept class or interface or typevar as first bound.
2944 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2945 boundSet.add(types.erasure(b));
2946 if (b.isErroneous()) {
2947 a.bound = b;
2948 }
2949 else if (b.tag == TYPEVAR) {
2950 // if first bound was a typevar, do not accept further bounds.
2951 if (tree.bounds.tail.nonEmpty()) {
2952 log.error(tree.bounds.tail.head.pos(),
2953 "type.var.may.not.be.followed.by.other.bounds");
2954 tree.bounds = List.of(tree.bounds.head);
2955 a.bound = bs.head;
2956 }
2957 } else {
2958 // if first bound was a class or interface, accept only interfaces
2959 // as further bounds.
2960 for (JCExpression bound : tree.bounds.tail) {
2961 bs = bs.tail;
2962 Type i = checkBase(bs.head, bound, env, false, true, false);
2963 if (i.isErroneous())
2964 a.bound = i;
2965 else if (i.tag == CLASS)
2966 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
2967 }
2968 }
2969 }
2970 bs = types.getBounds(a);
2972 // in case of multiple bounds ...
2973 if (bs.length() > 1) {
2974 // ... the variable's bound is a class type flagged COMPOUND
2975 // (see comment for TypeVar.bound).
2976 // In this case, generate a class tree that represents the
2977 // bound class, ...
2978 JCTree extending;
2979 List<JCExpression> implementing;
2980 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
2981 extending = tree.bounds.head;
2982 implementing = tree.bounds.tail;
2983 } else {
2984 extending = null;
2985 implementing = tree.bounds;
2986 }
2987 JCClassDecl cd = make.at(tree.pos).ClassDef(
2988 make.Modifiers(PUBLIC | ABSTRACT),
2989 tree.name, List.<JCTypeParameter>nil(),
2990 extending, implementing, List.<JCTree>nil());
2992 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
2993 Assert.check((c.flags() & COMPOUND) != 0);
2994 cd.sym = c;
2995 c.sourcefile = env.toplevel.sourcefile;
2997 // ... and attribute the bound class
2998 c.flags_field |= UNATTRIBUTED;
2999 Env<AttrContext> cenv = enter.classEnv(cd, env);
3000 enter.typeEnvs.put(c, cenv);
3001 }
3002 }
3005 public void visitWildcard(JCWildcard tree) {
3006 //- System.err.println("visitWildcard("+tree+");");//DEBUG
3007 Type type = (tree.kind.kind == BoundKind.UNBOUND)
3008 ? syms.objectType
3009 : attribType(tree.inner, env);
3010 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
3011 tree.kind.kind,
3012 syms.boundClass),
3013 TYP, pkind, pt);
3014 }
3016 public void visitAnnotation(JCAnnotation tree) {
3017 log.error(tree.pos(), "annotation.not.valid.for.type", pt);
3018 result = tree.type = syms.errType;
3019 }
3021 public void visitErroneous(JCErroneous tree) {
3022 if (tree.errs != null)
3023 for (JCTree err : tree.errs)
3024 attribTree(err, env, ERR, pt);
3025 result = tree.type = syms.errType;
3026 }
3028 /** Default visitor method for all other trees.
3029 */
3030 public void visitTree(JCTree tree) {
3031 throw new AssertionError();
3032 }
3034 /** Main method: attribute class definition associated with given class symbol.
3035 * reporting completion failures at the given position.
3036 * @param pos The source position at which completion errors are to be
3037 * reported.
3038 * @param c The class symbol whose definition will be attributed.
3039 */
3040 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
3041 try {
3042 annotate.flush();
3043 attribClass(c);
3044 } catch (CompletionFailure ex) {
3045 chk.completionError(pos, ex);
3046 }
3047 }
3049 /** Attribute class definition associated with given class symbol.
3050 * @param c The class symbol whose definition will be attributed.
3051 */
3052 void attribClass(ClassSymbol c) throws CompletionFailure {
3053 if (c.type.tag == ERROR) return;
3055 // Check for cycles in the inheritance graph, which can arise from
3056 // ill-formed class files.
3057 chk.checkNonCyclic(null, c.type);
3059 Type st = types.supertype(c.type);
3060 if ((c.flags_field & Flags.COMPOUND) == 0) {
3061 // First, attribute superclass.
3062 if (st.tag == CLASS)
3063 attribClass((ClassSymbol)st.tsym);
3065 // Next attribute owner, if it is a class.
3066 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
3067 attribClass((ClassSymbol)c.owner);
3068 }
3070 // The previous operations might have attributed the current class
3071 // if there was a cycle. So we test first whether the class is still
3072 // UNATTRIBUTED.
3073 if ((c.flags_field & UNATTRIBUTED) != 0) {
3074 c.flags_field &= ~UNATTRIBUTED;
3076 // Get environment current at the point of class definition.
3077 Env<AttrContext> env = enter.typeEnvs.get(c);
3079 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
3080 // because the annotations were not available at the time the env was created. Therefore,
3081 // we look up the environment chain for the first enclosing environment for which the
3082 // lint value is set. Typically, this is the parent env, but might be further if there
3083 // are any envs created as a result of TypeParameter nodes.
3084 Env<AttrContext> lintEnv = env;
3085 while (lintEnv.info.lint == null)
3086 lintEnv = lintEnv.next;
3088 // Having found the enclosing lint value, we can initialize the lint value for this class
3089 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
3091 Lint prevLint = chk.setLint(env.info.lint);
3092 JavaFileObject prev = log.useSource(c.sourcefile);
3094 try {
3095 // java.lang.Enum may not be subclassed by a non-enum
3096 if (st.tsym == syms.enumSym &&
3097 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
3098 log.error(env.tree.pos(), "enum.no.subclassing");
3100 // Enums may not be extended by source-level classes
3101 if (st.tsym != null &&
3102 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
3103 ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
3104 !target.compilerBootstrap(c)) {
3105 log.error(env.tree.pos(), "enum.types.not.extensible");
3106 }
3107 attribClassBody(env, c);
3109 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
3110 } finally {
3111 log.useSource(prev);
3112 chk.setLint(prevLint);
3113 }
3115 }
3116 }
3118 public void visitImport(JCImport tree) {
3119 // nothing to do
3120 }
3122 /** Finish the attribution of a class. */
3123 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
3124 JCClassDecl tree = (JCClassDecl)env.tree;
3125 Assert.check(c == tree.sym);
3127 // Validate annotations
3128 chk.validateAnnotations(tree.mods.annotations, c);
3130 // Validate type parameters, supertype and interfaces.
3131 attribBounds(tree.typarams);
3132 if (!c.isAnonymous()) {
3133 //already checked if anonymous
3134 chk.validate(tree.typarams, env);
3135 chk.validate(tree.extending, env);
3136 chk.validate(tree.implementing, env);
3137 }
3139 // If this is a non-abstract class, check that it has no abstract
3140 // methods or unimplemented methods of an implemented interface.
3141 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
3142 if (!relax)
3143 chk.checkAllDefined(tree.pos(), c);
3144 }
3146 if ((c.flags() & ANNOTATION) != 0) {
3147 if (tree.implementing.nonEmpty())
3148 log.error(tree.implementing.head.pos(),
3149 "cant.extend.intf.annotation");
3150 if (tree.typarams.nonEmpty())
3151 log.error(tree.typarams.head.pos(),
3152 "intf.annotation.cant.have.type.params");
3153 } else {
3154 // Check that all extended classes and interfaces
3155 // are compatible (i.e. no two define methods with same arguments
3156 // yet different return types). (JLS 8.4.6.3)
3157 chk.checkCompatibleSupertypes(tree.pos(), c.type);
3158 }
3160 // Check that class does not import the same parameterized interface
3161 // with two different argument lists.
3162 chk.checkClassBounds(tree.pos(), c.type);
3164 tree.type = c.type;
3166 for (List<JCTypeParameter> l = tree.typarams;
3167 l.nonEmpty(); l = l.tail) {
3168 Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope);
3169 }
3171 // Check that a generic class doesn't extend Throwable
3172 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
3173 log.error(tree.extending.pos(), "generic.throwable");
3175 // Check that all methods which implement some
3176 // method conform to the method they implement.
3177 chk.checkImplementations(tree);
3179 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3180 // Attribute declaration
3181 attribStat(l.head, env);
3182 // Check that declarations in inner classes are not static (JLS 8.1.2)
3183 // Make an exception for static constants.
3184 if (c.owner.kind != PCK &&
3185 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
3186 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
3187 Symbol sym = null;
3188 if (l.head.getTag() == JCTree.VARDEF) sym = ((JCVariableDecl) l.head).sym;
3189 if (sym == null ||
3190 sym.kind != VAR ||
3191 ((VarSymbol) sym).getConstValue() == null)
3192 log.error(l.head.pos(), "icls.cant.have.static.decl", c);
3193 }
3194 }
3196 // Check for cycles among non-initial constructors.
3197 chk.checkCyclicConstructors(tree);
3199 // Check for cycles among annotation elements.
3200 chk.checkNonCyclicElements(tree);
3202 // Check for proper use of serialVersionUID
3203 if (env.info.lint.isEnabled(LintCategory.SERIAL) &&
3204 isSerializable(c) &&
3205 (c.flags() & Flags.ENUM) == 0 &&
3206 (c.flags() & ABSTRACT) == 0) {
3207 checkSerialVersionUID(tree, c);
3208 }
3209 }
3210 // where
3211 /** check if a class is a subtype of Serializable, if that is available. */
3212 private boolean isSerializable(ClassSymbol c) {
3213 try {
3214 syms.serializableType.complete();
3215 }
3216 catch (CompletionFailure e) {
3217 return false;
3218 }
3219 return types.isSubtype(c.type, syms.serializableType);
3220 }
3222 /** Check that an appropriate serialVersionUID member is defined. */
3223 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
3225 // check for presence of serialVersionUID
3226 Scope.Entry e = c.members().lookup(names.serialVersionUID);
3227 while (e.scope != null && e.sym.kind != VAR) e = e.next();
3228 if (e.scope == null) {
3229 log.warning(LintCategory.SERIAL,
3230 tree.pos(), "missing.SVUID", c);
3231 return;
3232 }
3234 // check that it is static final
3235 VarSymbol svuid = (VarSymbol)e.sym;
3236 if ((svuid.flags() & (STATIC | FINAL)) !=
3237 (STATIC | FINAL))
3238 log.warning(LintCategory.SERIAL,
3239 TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
3241 // check that it is long
3242 else if (svuid.type.tag != TypeTags.LONG)
3243 log.warning(LintCategory.SERIAL,
3244 TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
3246 // check constant
3247 else if (svuid.getConstValue() == null)
3248 log.warning(LintCategory.SERIAL,
3249 TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
3250 }
3252 private Type capture(Type type) {
3253 return types.capture(type);
3254 }
3256 // <editor-fold desc="post-attribution visitor">
3258 /**
3259 * Handle missing types/symbols in an AST. This routine is useful when
3260 * the compiler has encountered some errors (which might have ended up
3261 * terminating attribution abruptly); if the compiler is used in fail-over
3262 * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
3263 * prevents NPE to be progagated during subsequent compilation steps.
3264 */
3265 public void postAttr(Env<AttrContext> env) {
3266 new PostAttrAnalyzer().scan(env.tree);
3267 }
3269 class PostAttrAnalyzer extends TreeScanner {
3271 private void initTypeIfNeeded(JCTree that) {
3272 if (that.type == null) {
3273 that.type = syms.unknownType;
3274 }
3275 }
3277 @Override
3278 public void scan(JCTree tree) {
3279 if (tree == null) return;
3280 if (tree instanceof JCExpression) {
3281 initTypeIfNeeded(tree);
3282 }
3283 super.scan(tree);
3284 }
3286 @Override
3287 public void visitIdent(JCIdent that) {
3288 if (that.sym == null) {
3289 that.sym = syms.unknownSymbol;
3290 }
3291 }
3293 @Override
3294 public void visitSelect(JCFieldAccess that) {
3295 if (that.sym == null) {
3296 that.sym = syms.unknownSymbol;
3297 }
3298 super.visitSelect(that);
3299 }
3301 @Override
3302 public void visitClassDef(JCClassDecl that) {
3303 initTypeIfNeeded(that);
3304 if (that.sym == null) {
3305 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
3306 }
3307 super.visitClassDef(that);
3308 }
3310 @Override
3311 public void visitMethodDef(JCMethodDecl that) {
3312 initTypeIfNeeded(that);
3313 if (that.sym == null) {
3314 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
3315 }
3316 super.visitMethodDef(that);
3317 }
3319 @Override
3320 public void visitVarDef(JCVariableDecl that) {
3321 initTypeIfNeeded(that);
3322 if (that.sym == null) {
3323 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
3324 that.sym.adr = 0;
3325 }
3326 super.visitVarDef(that);
3327 }
3329 @Override
3330 public void visitNewClass(JCNewClass that) {
3331 if (that.constructor == null) {
3332 that.constructor = new MethodSymbol(0, names.init, syms.unknownType, syms.noSymbol);
3333 }
3334 if (that.constructorType == null) {
3335 that.constructorType = syms.unknownType;
3336 }
3337 super.visitNewClass(that);
3338 }
3340 @Override
3341 public void visitBinary(JCBinary that) {
3342 if (that.operator == null)
3343 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3344 super.visitBinary(that);
3345 }
3347 @Override
3348 public void visitUnary(JCUnary that) {
3349 if (that.operator == null)
3350 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3351 super.visitUnary(that);
3352 }
3353 }
3354 // </editor-fold>
3355 }