Wed, 26 Sep 2012 14:22:41 +0100
7188968: New instance creation expression using diamond is checked twice
Summary: Unify method and constructor check logic
Reviewed-by: jjg
1 /*
2 * Copyright (c) 1999, 2012, 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.*;
45 import com.sun.tools.javac.comp.Check.CheckContext;
47 import com.sun.source.tree.IdentifierTree;
48 import com.sun.source.tree.MemberSelectTree;
49 import com.sun.source.tree.TreeVisitor;
50 import com.sun.source.util.SimpleTreeVisitor;
52 import static com.sun.tools.javac.code.Flags.*;
53 import static com.sun.tools.javac.code.Flags.ANNOTATION;
54 import static com.sun.tools.javac.code.Flags.BLOCK;
55 import static com.sun.tools.javac.code.Kinds.*;
56 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
57 import static com.sun.tools.javac.code.TypeTags.*;
58 import static com.sun.tools.javac.code.TypeTags.WILDCARD;
59 import static com.sun.tools.javac.tree.JCTree.Tag.*;
61 /** This is the main context-dependent analysis phase in GJC. It
62 * encompasses name resolution, type checking and constant folding as
63 * subtasks. Some subtasks involve auxiliary classes.
64 * @see Check
65 * @see Resolve
66 * @see ConstFold
67 * @see Infer
68 *
69 * <p><b>This is NOT part of any supported API.
70 * If you write code that depends on this, you do so at your own risk.
71 * This code and its internal interfaces are subject to change or
72 * deletion without notice.</b>
73 */
74 public class Attr extends JCTree.Visitor {
75 protected static final Context.Key<Attr> attrKey =
76 new Context.Key<Attr>();
78 final Names names;
79 final Log log;
80 final Symtab syms;
81 final Resolve rs;
82 final Infer infer;
83 final Check chk;
84 final MemberEnter memberEnter;
85 final TreeMaker make;
86 final ConstFold cfolder;
87 final Enter enter;
88 final Target target;
89 final Types types;
90 final JCDiagnostic.Factory diags;
91 final Annotate annotate;
92 final DeferredLintHandler deferredLintHandler;
94 public static Attr instance(Context context) {
95 Attr instance = context.get(attrKey);
96 if (instance == null)
97 instance = new Attr(context);
98 return instance;
99 }
101 protected Attr(Context context) {
102 context.put(attrKey, this);
104 names = Names.instance(context);
105 log = Log.instance(context);
106 syms = Symtab.instance(context);
107 rs = Resolve.instance(context);
108 chk = Check.instance(context);
109 memberEnter = MemberEnter.instance(context);
110 make = TreeMaker.instance(context);
111 enter = Enter.instance(context);
112 infer = Infer.instance(context);
113 cfolder = ConstFold.instance(context);
114 target = Target.instance(context);
115 types = Types.instance(context);
116 diags = JCDiagnostic.Factory.instance(context);
117 annotate = Annotate.instance(context);
118 deferredLintHandler = DeferredLintHandler.instance(context);
120 Options options = Options.instance(context);
122 Source source = Source.instance(context);
123 allowGenerics = source.allowGenerics();
124 allowVarargs = source.allowVarargs();
125 allowEnums = source.allowEnums();
126 allowBoxing = source.allowBoxing();
127 allowCovariantReturns = source.allowCovariantReturns();
128 allowAnonOuterThis = source.allowAnonOuterThis();
129 allowStringsInSwitch = source.allowStringsInSwitch();
130 sourceName = source.name;
131 relax = (options.isSet("-retrofit") ||
132 options.isSet("-relax"));
133 findDiamonds = options.get("findDiamond") != null &&
134 source.allowDiamond();
135 useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
137 statInfo = new ResultInfo(NIL, Type.noType);
138 varInfo = new ResultInfo(VAR, Type.noType);
139 unknownExprInfo = new ResultInfo(VAL, Type.noType);
140 unknownTypeInfo = new ResultInfo(TYP, Type.noType);
141 }
143 /** Switch: relax some constraints for retrofit mode.
144 */
145 boolean relax;
147 /** Switch: support generics?
148 */
149 boolean allowGenerics;
151 /** Switch: allow variable-arity methods.
152 */
153 boolean allowVarargs;
155 /** Switch: support enums?
156 */
157 boolean allowEnums;
159 /** Switch: support boxing and unboxing?
160 */
161 boolean allowBoxing;
163 /** Switch: support covariant result types?
164 */
165 boolean allowCovariantReturns;
167 /** Switch: allow references to surrounding object from anonymous
168 * objects during constructor call?
169 */
170 boolean allowAnonOuterThis;
172 /** Switch: generates a warning if diamond can be safely applied
173 * to a given new expression
174 */
175 boolean findDiamonds;
177 /**
178 * Internally enables/disables diamond finder feature
179 */
180 static final boolean allowDiamondFinder = true;
182 /**
183 * Switch: warn about use of variable before declaration?
184 * RFE: 6425594
185 */
186 boolean useBeforeDeclarationWarning;
188 /**
189 * Switch: allow strings in switch?
190 */
191 boolean allowStringsInSwitch;
193 /**
194 * Switch: name of source level; used for error reporting.
195 */
196 String sourceName;
198 /** Check kind and type of given tree against protokind and prototype.
199 * If check succeeds, store type in tree and return it.
200 * If check fails, store errType in tree and return it.
201 * No checks are performed if the prototype is a method type.
202 * It is not necessary in this case since we know that kind and type
203 * are correct.
204 *
205 * @param tree The tree whose kind and type is checked
206 * @param owntype The computed type of the tree
207 * @param ownkind The computed kind of the tree
208 * @param resultInfo The expected result of the tree
209 */
210 Type check(JCTree tree, Type owntype, int ownkind, ResultInfo resultInfo) {
211 if (owntype.tag != ERROR && resultInfo.pt.tag != METHOD && resultInfo.pt.tag != FORALL) {
212 if ((ownkind & ~resultInfo.pkind) == 0) {
213 owntype = resultInfo.check(tree, owntype);
214 } else {
215 log.error(tree.pos(), "unexpected.type",
216 kindNames(resultInfo.pkind),
217 kindName(ownkind));
218 owntype = types.createErrorType(owntype);
219 }
220 }
221 tree.type = owntype;
222 return owntype;
223 }
225 /** Is given blank final variable assignable, i.e. in a scope where it
226 * may be assigned to even though it is final?
227 * @param v The blank final variable.
228 * @param env The current environment.
229 */
230 boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
231 Symbol owner = owner(env);
232 // owner refers to the innermost variable, method or
233 // initializer block declaration at this point.
234 return
235 v.owner == owner
236 ||
237 ((owner.name == names.init || // i.e. we are in a constructor
238 owner.kind == VAR || // i.e. we are in a variable initializer
239 (owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
240 &&
241 v.owner == owner.owner
242 &&
243 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
244 }
246 /**
247 * Return the innermost enclosing owner symbol in a given attribution context
248 */
249 Symbol owner(Env<AttrContext> env) {
250 while (true) {
251 switch (env.tree.getTag()) {
252 case VARDEF:
253 //a field can be owner
254 VarSymbol vsym = ((JCVariableDecl)env.tree).sym;
255 if (vsym.owner.kind == TYP) {
256 return vsym;
257 }
258 break;
259 case METHODDEF:
260 //method def is always an owner
261 return ((JCMethodDecl)env.tree).sym;
262 case CLASSDEF:
263 //class def is always an owner
264 return ((JCClassDecl)env.tree).sym;
265 case BLOCK:
266 //static/instance init blocks are owner
267 Symbol blockSym = env.info.scope.owner;
268 if ((blockSym.flags() & BLOCK) != 0) {
269 return blockSym;
270 }
271 break;
272 case TOPLEVEL:
273 //toplevel is always an owner (for pkge decls)
274 return env.info.scope.owner;
275 }
276 Assert.checkNonNull(env.next);
277 env = env.next;
278 }
279 }
281 /** Check that variable can be assigned to.
282 * @param pos The current source code position.
283 * @param v The assigned varaible
284 * @param base If the variable is referred to in a Select, the part
285 * to the left of the `.', null otherwise.
286 * @param env The current environment.
287 */
288 void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
289 if ((v.flags() & FINAL) != 0 &&
290 ((v.flags() & HASINIT) != 0
291 ||
292 !((base == null ||
293 (base.hasTag(IDENT) && TreeInfo.name(base) == names._this)) &&
294 isAssignableAsBlankFinal(v, env)))) {
295 if (v.isResourceVariable()) { //TWR resource
296 log.error(pos, "try.resource.may.not.be.assigned", v);
297 } else {
298 log.error(pos, "cant.assign.val.to.final.var", v);
299 }
300 } else if ((v.flags() & EFFECTIVELY_FINAL) != 0) {
301 v.flags_field &= ~EFFECTIVELY_FINAL;
302 }
303 }
305 /** Does tree represent a static reference to an identifier?
306 * It is assumed that tree is either a SELECT or an IDENT.
307 * We have to weed out selects from non-type names here.
308 * @param tree The candidate tree.
309 */
310 boolean isStaticReference(JCTree tree) {
311 if (tree.hasTag(SELECT)) {
312 Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
313 if (lsym == null || lsym.kind != TYP) {
314 return false;
315 }
316 }
317 return true;
318 }
320 /** Is this symbol a type?
321 */
322 static boolean isType(Symbol sym) {
323 return sym != null && sym.kind == TYP;
324 }
326 /** The current `this' symbol.
327 * @param env The current environment.
328 */
329 Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
330 return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
331 }
333 /** Attribute a parsed identifier.
334 * @param tree Parsed identifier name
335 * @param topLevel The toplevel to use
336 */
337 public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
338 Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
339 localEnv.enclClass = make.ClassDef(make.Modifiers(0),
340 syms.errSymbol.name,
341 null, null, null, null);
342 localEnv.enclClass.sym = syms.errSymbol;
343 return tree.accept(identAttributer, localEnv);
344 }
345 // where
346 private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
347 private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
348 @Override
349 public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
350 Symbol site = visit(node.getExpression(), env);
351 if (site.kind == ERR)
352 return site;
353 Name name = (Name)node.getIdentifier();
354 if (site.kind == PCK) {
355 env.toplevel.packge = (PackageSymbol)site;
356 return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
357 } else {
358 env.enclClass.sym = (ClassSymbol)site;
359 return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
360 }
361 }
363 @Override
364 public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
365 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
366 }
367 }
369 public Type coerce(Type etype, Type ttype) {
370 return cfolder.coerce(etype, ttype);
371 }
373 public Type attribType(JCTree node, TypeSymbol sym) {
374 Env<AttrContext> env = enter.typeEnvs.get(sym);
375 Env<AttrContext> localEnv = env.dup(node, env.info.dup());
376 return attribTree(node, localEnv, unknownTypeInfo);
377 }
379 public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
380 // Attribute qualifying package or class.
381 JCFieldAccess s = (JCFieldAccess)tree.qualid;
382 return attribTree(s.selected,
383 env,
384 new ResultInfo(tree.staticImport ? TYP : (TYP | PCK),
385 Type.noType));
386 }
388 public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
389 breakTree = tree;
390 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
391 try {
392 attribExpr(expr, env);
393 } catch (BreakAttr b) {
394 return b.env;
395 } catch (AssertionError ae) {
396 if (ae.getCause() instanceof BreakAttr) {
397 return ((BreakAttr)(ae.getCause())).env;
398 } else {
399 throw ae;
400 }
401 } finally {
402 breakTree = null;
403 log.useSource(prev);
404 }
405 return env;
406 }
408 public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
409 breakTree = tree;
410 JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
411 try {
412 attribStat(stmt, env);
413 } catch (BreakAttr b) {
414 return b.env;
415 } catch (AssertionError ae) {
416 if (ae.getCause() instanceof BreakAttr) {
417 return ((BreakAttr)(ae.getCause())).env;
418 } else {
419 throw ae;
420 }
421 } finally {
422 breakTree = null;
423 log.useSource(prev);
424 }
425 return env;
426 }
428 private JCTree breakTree = null;
430 private static class BreakAttr extends RuntimeException {
431 static final long serialVersionUID = -6924771130405446405L;
432 private Env<AttrContext> env;
433 private BreakAttr(Env<AttrContext> env) {
434 this.env = env;
435 }
436 }
438 class ResultInfo {
439 int pkind;
440 Type pt;
441 CheckContext checkContext;
443 ResultInfo(int pkind, Type pt) {
444 this(pkind, pt, chk.basicHandler);
445 }
447 protected ResultInfo(int pkind, Type pt, CheckContext checkContext) {
448 this.pkind = pkind;
449 this.pt = pt;
450 this.checkContext = checkContext;
451 }
453 protected Type check(DiagnosticPosition pos, Type found) {
454 return chk.checkType(pos, found, pt, checkContext);
455 }
456 }
458 private final ResultInfo statInfo;
459 private final ResultInfo varInfo;
460 private final ResultInfo unknownExprInfo;
461 private final ResultInfo unknownTypeInfo;
463 Type pt() {
464 return resultInfo.pt;
465 }
467 int pkind() {
468 return resultInfo.pkind;
469 }
471 /* ************************************************************************
472 * Visitor methods
473 *************************************************************************/
475 /** Visitor argument: the current environment.
476 */
477 Env<AttrContext> env;
479 /** Visitor argument: the currently expected attribution result.
480 */
481 ResultInfo resultInfo;
483 /** Visitor result: the computed type.
484 */
485 Type result;
487 /** Visitor method: attribute a tree, catching any completion failure
488 * exceptions. Return the tree's type.
489 *
490 * @param tree The tree to be visited.
491 * @param env The environment visitor argument.
492 * @param resultInfo The result info visitor argument.
493 */
494 private Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
495 Env<AttrContext> prevEnv = this.env;
496 ResultInfo prevResult = this.resultInfo;
497 try {
498 this.env = env;
499 this.resultInfo = resultInfo;
500 tree.accept(this);
501 if (tree == breakTree)
502 throw new BreakAttr(env);
503 return result;
504 } catch (CompletionFailure ex) {
505 tree.type = syms.errType;
506 return chk.completionError(tree.pos(), ex);
507 } finally {
508 this.env = prevEnv;
509 this.resultInfo = prevResult;
510 }
511 }
513 /** Derived visitor method: attribute an expression tree.
514 */
515 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
516 return attribTree(tree, env, new ResultInfo(VAL, pt.tag != ERROR ? pt : Type.noType));
517 }
519 /** Derived visitor method: attribute an expression tree with
520 * no constraints on the computed type.
521 */
522 Type attribExpr(JCTree tree, Env<AttrContext> env) {
523 return attribTree(tree, env, unknownExprInfo);
524 }
526 /** Derived visitor method: attribute a type tree.
527 */
528 Type attribType(JCTree tree, Env<AttrContext> env) {
529 Type result = attribType(tree, env, Type.noType);
530 return result;
531 }
533 /** Derived visitor method: attribute a type tree.
534 */
535 Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
536 Type result = attribTree(tree, env, new ResultInfo(TYP, pt));
537 return result;
538 }
540 /** Derived visitor method: attribute a statement or definition tree.
541 */
542 public Type attribStat(JCTree tree, Env<AttrContext> env) {
543 return attribTree(tree, env, statInfo);
544 }
546 /** Attribute a list of expressions, returning a list of types.
547 */
548 List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
549 ListBuffer<Type> ts = new ListBuffer<Type>();
550 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
551 ts.append(attribExpr(l.head, env, pt));
552 return ts.toList();
553 }
555 /** Attribute a list of statements, returning nothing.
556 */
557 <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
558 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
559 attribStat(l.head, env);
560 }
562 /** Attribute the arguments in a method call, returning a list of types.
563 */
564 List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
565 ListBuffer<Type> argtypes = new ListBuffer<Type>();
566 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
567 argtypes.append(chk.checkNonVoid(
568 l.head.pos(), types.upperBound(attribExpr(l.head, env, Infer.anyPoly))));
569 return argtypes.toList();
570 }
572 /** Attribute a type argument list, returning a list of types.
573 * Caller is responsible for calling checkRefTypes.
574 */
575 List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
576 ListBuffer<Type> argtypes = new ListBuffer<Type>();
577 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
578 argtypes.append(attribType(l.head, env));
579 return argtypes.toList();
580 }
582 /** Attribute a type argument list, returning a list of types.
583 * Check that all the types are references.
584 */
585 List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
586 List<Type> types = attribAnyTypes(trees, env);
587 return chk.checkRefTypes(trees, types);
588 }
590 /**
591 * Attribute type variables (of generic classes or methods).
592 * Compound types are attributed later in attribBounds.
593 * @param typarams the type variables to enter
594 * @param env the current environment
595 */
596 void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
597 for (JCTypeParameter tvar : typarams) {
598 TypeVar a = (TypeVar)tvar.type;
599 a.tsym.flags_field |= UNATTRIBUTED;
600 a.bound = Type.noType;
601 if (!tvar.bounds.isEmpty()) {
602 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
603 for (JCExpression bound : tvar.bounds.tail)
604 bounds = bounds.prepend(attribType(bound, env));
605 types.setBounds(a, bounds.reverse());
606 } else {
607 // if no bounds are given, assume a single bound of
608 // java.lang.Object.
609 types.setBounds(a, List.of(syms.objectType));
610 }
611 a.tsym.flags_field &= ~UNATTRIBUTED;
612 }
613 for (JCTypeParameter tvar : typarams)
614 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
615 attribStats(typarams, env);
616 }
618 void attribBounds(List<JCTypeParameter> typarams) {
619 for (JCTypeParameter typaram : typarams) {
620 Type bound = typaram.type.getUpperBound();
621 if (bound != null && bound.tsym instanceof ClassSymbol) {
622 ClassSymbol c = (ClassSymbol)bound.tsym;
623 if ((c.flags_field & COMPOUND) != 0) {
624 Assert.check((c.flags_field & UNATTRIBUTED) != 0, c);
625 attribClass(typaram.pos(), c);
626 }
627 }
628 }
629 }
631 /**
632 * Attribute the type references in a list of annotations.
633 */
634 void attribAnnotationTypes(List<JCAnnotation> annotations,
635 Env<AttrContext> env) {
636 for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
637 JCAnnotation a = al.head;
638 attribType(a.annotationType, env);
639 }
640 }
642 /**
643 * Attribute a "lazy constant value".
644 * @param env The env for the const value
645 * @param initializer The initializer for the const value
646 * @param type The expected type, or null
647 * @see VarSymbol#setlazyConstValue
648 */
649 public Object attribLazyConstantValue(Env<AttrContext> env,
650 JCTree.JCExpression initializer,
651 Type type) {
653 // in case no lint value has been set up for this env, scan up
654 // env stack looking for smallest enclosing env for which it is set.
655 Env<AttrContext> lintEnv = env;
656 while (lintEnv.info.lint == null)
657 lintEnv = lintEnv.next;
659 // Having found the enclosing lint value, we can initialize the lint value for this class
660 // ... but ...
661 // There's a problem with evaluating annotations in the right order, such that
662 // env.info.enclVar.attributes_field might not yet have been evaluated, and so might be
663 // null. In that case, calling augment will throw an NPE. To avoid this, for now we
664 // revert to the jdk 6 behavior and ignore the (unevaluated) attributes.
665 if (env.info.enclVar.annotations.pendingCompletion()) {
666 env.info.lint = lintEnv.info.lint;
667 } else {
668 env.info.lint = lintEnv.info.lint.augment(env.info.enclVar.annotations,
669 env.info.enclVar.flags());
670 }
672 Lint prevLint = chk.setLint(env.info.lint);
673 JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
675 try {
676 Type itype = attribExpr(initializer, env, type);
677 if (itype.constValue() != null)
678 return coerce(itype, type).constValue();
679 else
680 return null;
681 } finally {
682 env.info.lint = prevLint;
683 log.useSource(prevSource);
684 }
685 }
687 /** Attribute type reference in an `extends' or `implements' clause.
688 * Supertypes of anonymous inner classes are usually already attributed.
689 *
690 * @param tree The tree making up the type reference.
691 * @param env The environment current at the reference.
692 * @param classExpected true if only a class is expected here.
693 * @param interfaceExpected true if only an interface is expected here.
694 */
695 Type attribBase(JCTree tree,
696 Env<AttrContext> env,
697 boolean classExpected,
698 boolean interfaceExpected,
699 boolean checkExtensible) {
700 Type t = tree.type != null ?
701 tree.type :
702 attribType(tree, env);
703 return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
704 }
705 Type checkBase(Type t,
706 JCTree tree,
707 Env<AttrContext> env,
708 boolean classExpected,
709 boolean interfaceExpected,
710 boolean checkExtensible) {
711 if (t.isErroneous())
712 return t;
713 if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
714 // check that type variable is already visible
715 if (t.getUpperBound() == null) {
716 log.error(tree.pos(), "illegal.forward.ref");
717 return types.createErrorType(t);
718 }
719 } else {
720 t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
721 }
722 if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
723 log.error(tree.pos(), "intf.expected.here");
724 // return errType is necessary since otherwise there might
725 // be undetected cycles which cause attribution to loop
726 return types.createErrorType(t);
727 } else if (checkExtensible &&
728 classExpected &&
729 (t.tsym.flags() & INTERFACE) != 0) {
730 log.error(tree.pos(), "no.intf.expected.here");
731 return types.createErrorType(t);
732 }
733 if (checkExtensible &&
734 ((t.tsym.flags() & FINAL) != 0)) {
735 log.error(tree.pos(),
736 "cant.inherit.from.final", t.tsym);
737 }
738 chk.checkNonCyclic(tree.pos(), t);
739 return t;
740 }
742 Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
743 Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
744 id.type = env.info.scope.owner.type;
745 id.sym = env.info.scope.owner;
746 return id.type;
747 }
749 public void visitClassDef(JCClassDecl tree) {
750 // Local classes have not been entered yet, so we need to do it now:
751 if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
752 enter.classEnter(tree, env);
754 ClassSymbol c = tree.sym;
755 if (c == null) {
756 // exit in case something drastic went wrong during enter.
757 result = null;
758 } else {
759 // make sure class has been completed:
760 c.complete();
762 // If this class appears as an anonymous class
763 // in a superclass constructor call where
764 // no explicit outer instance is given,
765 // disable implicit outer instance from being passed.
766 // (This would be an illegal access to "this before super").
767 if (env.info.isSelfCall &&
768 env.tree.hasTag(NEWCLASS) &&
769 ((JCNewClass) env.tree).encl == null)
770 {
771 c.flags_field |= NOOUTERTHIS;
772 }
773 attribClass(tree.pos(), c);
774 result = tree.type = c.type;
775 }
776 }
778 public void visitMethodDef(JCMethodDecl tree) {
779 MethodSymbol m = tree.sym;
781 Lint lint = env.info.lint.augment(m.annotations, m.flags());
782 Lint prevLint = chk.setLint(lint);
783 MethodSymbol prevMethod = chk.setMethod(m);
784 try {
785 deferredLintHandler.flush(tree.pos());
786 chk.checkDeprecatedAnnotation(tree.pos(), m);
788 attribBounds(tree.typarams);
790 // If we override any other methods, check that we do so properly.
791 // JLS ???
792 if (m.isStatic()) {
793 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
794 } else {
795 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
796 }
797 chk.checkOverride(tree, m);
799 // Create a new environment with local scope
800 // for attributing the method.
801 Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
803 localEnv.info.lint = lint;
805 // Enter all type parameters into the local method scope.
806 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
807 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
809 ClassSymbol owner = env.enclClass.sym;
810 if ((owner.flags() & ANNOTATION) != 0 &&
811 tree.params.nonEmpty())
812 log.error(tree.params.head.pos(),
813 "intf.annotation.members.cant.have.params");
815 // Attribute all value parameters.
816 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
817 attribStat(l.head, localEnv);
818 }
820 chk.checkVarargsMethodDecl(localEnv, tree);
822 // Check that type parameters are well-formed.
823 chk.validate(tree.typarams, localEnv);
825 // Check that result type is well-formed.
826 chk.validate(tree.restype, localEnv);
828 // annotation method checks
829 if ((owner.flags() & ANNOTATION) != 0) {
830 // annotation method cannot have throws clause
831 if (tree.thrown.nonEmpty()) {
832 log.error(tree.thrown.head.pos(),
833 "throws.not.allowed.in.intf.annotation");
834 }
835 // annotation method cannot declare type-parameters
836 if (tree.typarams.nonEmpty()) {
837 log.error(tree.typarams.head.pos(),
838 "intf.annotation.members.cant.have.type.params");
839 }
840 // validate annotation method's return type (could be an annotation type)
841 chk.validateAnnotationType(tree.restype);
842 // ensure that annotation method does not clash with members of Object/Annotation
843 chk.validateAnnotationMethod(tree.pos(), m);
845 if (tree.defaultValue != null) {
846 // if default value is an annotation, check it is a well-formed
847 // annotation value (e.g. no duplicate values, no missing values, etc.)
848 chk.validateAnnotationTree(tree.defaultValue);
849 }
850 }
852 for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
853 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
855 if (tree.body == null) {
856 // Empty bodies are only allowed for
857 // abstract, native, or interface methods, or for methods
858 // in a retrofit signature class.
859 if ((owner.flags() & INTERFACE) == 0 &&
860 (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 &&
861 !relax)
862 log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
863 if (tree.defaultValue != null) {
864 if ((owner.flags() & ANNOTATION) == 0)
865 log.error(tree.pos(),
866 "default.allowed.in.intf.annotation.member");
867 }
868 } else if ((owner.flags() & INTERFACE) != 0) {
869 log.error(tree.body.pos(), "intf.meth.cant.have.body");
870 } else if ((tree.mods.flags & ABSTRACT) != 0) {
871 log.error(tree.pos(), "abstract.meth.cant.have.body");
872 } else if ((tree.mods.flags & NATIVE) != 0) {
873 log.error(tree.pos(), "native.meth.cant.have.body");
874 } else {
875 // Add an implicit super() call unless an explicit call to
876 // super(...) or this(...) is given
877 // or we are compiling class java.lang.Object.
878 if (tree.name == names.init && owner.type != syms.objectType) {
879 JCBlock body = tree.body;
880 if (body.stats.isEmpty() ||
881 !TreeInfo.isSelfCall(body.stats.head)) {
882 body.stats = body.stats.
883 prepend(memberEnter.SuperCall(make.at(body.pos),
884 List.<Type>nil(),
885 List.<JCVariableDecl>nil(),
886 false));
887 } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
888 (tree.mods.flags & GENERATEDCONSTR) == 0 &&
889 TreeInfo.isSuperCall(body.stats.head)) {
890 // enum constructors are not allowed to call super
891 // directly, so make sure there aren't any super calls
892 // in enum constructors, except in the compiler
893 // generated one.
894 log.error(tree.body.stats.head.pos(),
895 "call.to.super.not.allowed.in.enum.ctor",
896 env.enclClass.sym);
897 }
898 }
900 // Attribute method body.
901 attribStat(tree.body, localEnv);
902 }
903 localEnv.info.scope.leave();
904 result = tree.type = m.type;
905 chk.validateAnnotations(tree.mods.annotations, m);
906 }
907 finally {
908 chk.setLint(prevLint);
909 chk.setMethod(prevMethod);
910 }
911 }
913 public void visitVarDef(JCVariableDecl tree) {
914 // Local variables have not been entered yet, so we need to do it now:
915 if (env.info.scope.owner.kind == MTH) {
916 if (tree.sym != null) {
917 // parameters have already been entered
918 env.info.scope.enter(tree.sym);
919 } else {
920 memberEnter.memberEnter(tree, env);
921 annotate.flush();
922 }
923 }
925 VarSymbol v = tree.sym;
926 Lint lint = env.info.lint.augment(v.annotations, v.flags());
927 Lint prevLint = chk.setLint(lint);
929 // Check that the variable's declared type is well-formed.
930 chk.validate(tree.vartype, env);
931 deferredLintHandler.flush(tree.pos());
933 try {
934 chk.checkDeprecatedAnnotation(tree.pos(), v);
936 if (tree.init != null) {
937 if ((v.flags_field & FINAL) != 0 && !tree.init.hasTag(NEWCLASS)) {
938 // In this case, `v' is final. Ensure that it's initializer is
939 // evaluated.
940 v.getConstValue(); // ensure initializer is evaluated
941 } else {
942 // Attribute initializer in a new environment
943 // with the declared variable as owner.
944 // Check that initializer conforms to variable's declared type.
945 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
946 initEnv.info.lint = lint;
947 // In order to catch self-references, we set the variable's
948 // declaration position to maximal possible value, effectively
949 // marking the variable as undefined.
950 initEnv.info.enclVar = v;
951 attribExpr(tree.init, initEnv, v.type);
952 }
953 }
954 result = tree.type = v.type;
955 chk.validateAnnotations(tree.mods.annotations, v);
956 }
957 finally {
958 chk.setLint(prevLint);
959 }
960 }
962 public void visitSkip(JCSkip tree) {
963 result = null;
964 }
966 public void visitBlock(JCBlock tree) {
967 if (env.info.scope.owner.kind == TYP) {
968 // Block is a static or instance initializer;
969 // let the owner of the environment be a freshly
970 // created BLOCK-method.
971 Env<AttrContext> localEnv =
972 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
973 localEnv.info.scope.owner =
974 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
975 env.info.scope.owner);
976 if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
977 attribStats(tree.stats, localEnv);
978 } else {
979 // Create a new local environment with a local scope.
980 Env<AttrContext> localEnv =
981 env.dup(tree, env.info.dup(env.info.scope.dup()));
982 attribStats(tree.stats, localEnv);
983 localEnv.info.scope.leave();
984 }
985 result = null;
986 }
988 public void visitDoLoop(JCDoWhileLoop tree) {
989 attribStat(tree.body, env.dup(tree));
990 attribExpr(tree.cond, env, syms.booleanType);
991 result = null;
992 }
994 public void visitWhileLoop(JCWhileLoop tree) {
995 attribExpr(tree.cond, env, syms.booleanType);
996 attribStat(tree.body, env.dup(tree));
997 result = null;
998 }
1000 public void visitForLoop(JCForLoop tree) {
1001 Env<AttrContext> loopEnv =
1002 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1003 attribStats(tree.init, loopEnv);
1004 if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
1005 loopEnv.tree = tree; // before, we were not in loop!
1006 attribStats(tree.step, loopEnv);
1007 attribStat(tree.body, loopEnv);
1008 loopEnv.info.scope.leave();
1009 result = null;
1010 }
1012 public void visitForeachLoop(JCEnhancedForLoop tree) {
1013 Env<AttrContext> loopEnv =
1014 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1015 attribStat(tree.var, loopEnv);
1016 Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
1017 chk.checkNonVoid(tree.pos(), exprType);
1018 Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1019 if (elemtype == null) {
1020 // or perhaps expr implements Iterable<T>?
1021 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1022 if (base == null) {
1023 log.error(tree.expr.pos(),
1024 "foreach.not.applicable.to.type",
1025 exprType,
1026 diags.fragment("type.req.array.or.iterable"));
1027 elemtype = types.createErrorType(exprType);
1028 } else {
1029 List<Type> iterableParams = base.allparams();
1030 elemtype = iterableParams.isEmpty()
1031 ? syms.objectType
1032 : types.upperBound(iterableParams.head);
1033 }
1034 }
1035 chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1036 loopEnv.tree = tree; // before, we were not in loop!
1037 attribStat(tree.body, loopEnv);
1038 loopEnv.info.scope.leave();
1039 result = null;
1040 }
1042 public void visitLabelled(JCLabeledStatement tree) {
1043 // Check that label is not used in an enclosing statement
1044 Env<AttrContext> env1 = env;
1045 while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1046 if (env1.tree.hasTag(LABELLED) &&
1047 ((JCLabeledStatement) env1.tree).label == tree.label) {
1048 log.error(tree.pos(), "label.already.in.use",
1049 tree.label);
1050 break;
1051 }
1052 env1 = env1.next;
1053 }
1055 attribStat(tree.body, env.dup(tree));
1056 result = null;
1057 }
1059 public void visitSwitch(JCSwitch tree) {
1060 Type seltype = attribExpr(tree.selector, env);
1062 Env<AttrContext> switchEnv =
1063 env.dup(tree, env.info.dup(env.info.scope.dup()));
1065 boolean enumSwitch =
1066 allowEnums &&
1067 (seltype.tsym.flags() & Flags.ENUM) != 0;
1068 boolean stringSwitch = false;
1069 if (types.isSameType(seltype, syms.stringType)) {
1070 if (allowStringsInSwitch) {
1071 stringSwitch = true;
1072 } else {
1073 log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName);
1074 }
1075 }
1076 if (!enumSwitch && !stringSwitch)
1077 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
1079 // Attribute all cases and
1080 // check that there are no duplicate case labels or default clauses.
1081 Set<Object> labels = new HashSet<Object>(); // The set of case labels.
1082 boolean hasDefault = false; // Is there a default label?
1083 for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
1084 JCCase c = l.head;
1085 Env<AttrContext> caseEnv =
1086 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
1087 if (c.pat != null) {
1088 if (enumSwitch) {
1089 Symbol sym = enumConstant(c.pat, seltype);
1090 if (sym == null) {
1091 log.error(c.pat.pos(), "enum.label.must.be.unqualified.enum");
1092 } else if (!labels.add(sym)) {
1093 log.error(c.pos(), "duplicate.case.label");
1094 }
1095 } else {
1096 Type pattype = attribExpr(c.pat, switchEnv, seltype);
1097 if (pattype.tag != ERROR) {
1098 if (pattype.constValue() == null) {
1099 log.error(c.pat.pos(),
1100 (stringSwitch ? "string.const.req" : "const.expr.req"));
1101 } else if (labels.contains(pattype.constValue())) {
1102 log.error(c.pos(), "duplicate.case.label");
1103 } else {
1104 labels.add(pattype.constValue());
1105 }
1106 }
1107 }
1108 } else if (hasDefault) {
1109 log.error(c.pos(), "duplicate.default.label");
1110 } else {
1111 hasDefault = true;
1112 }
1113 attribStats(c.stats, caseEnv);
1114 caseEnv.info.scope.leave();
1115 addVars(c.stats, switchEnv.info.scope);
1116 }
1118 switchEnv.info.scope.leave();
1119 result = null;
1120 }
1121 // where
1122 /** Add any variables defined in stats to the switch scope. */
1123 private static void addVars(List<JCStatement> stats, Scope switchScope) {
1124 for (;stats.nonEmpty(); stats = stats.tail) {
1125 JCTree stat = stats.head;
1126 if (stat.hasTag(VARDEF))
1127 switchScope.enter(((JCVariableDecl) stat).sym);
1128 }
1129 }
1130 // where
1131 /** Return the selected enumeration constant symbol, or null. */
1132 private Symbol enumConstant(JCTree tree, Type enumType) {
1133 if (!tree.hasTag(IDENT)) {
1134 log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
1135 return syms.errSymbol;
1136 }
1137 JCIdent ident = (JCIdent)tree;
1138 Name name = ident.name;
1139 for (Scope.Entry e = enumType.tsym.members().lookup(name);
1140 e.scope != null; e = e.next()) {
1141 if (e.sym.kind == VAR) {
1142 Symbol s = ident.sym = e.sym;
1143 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1144 ident.type = s.type;
1145 return ((s.flags_field & Flags.ENUM) == 0)
1146 ? null : s;
1147 }
1148 }
1149 return null;
1150 }
1152 public void visitSynchronized(JCSynchronized tree) {
1153 chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
1154 attribStat(tree.body, env);
1155 result = null;
1156 }
1158 public void visitTry(JCTry tree) {
1159 // Create a new local environment with a local
1160 Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1161 boolean isTryWithResource = tree.resources.nonEmpty();
1162 // Create a nested environment for attributing the try block if needed
1163 Env<AttrContext> tryEnv = isTryWithResource ?
1164 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1165 localEnv;
1166 // Attribute resource declarations
1167 for (JCTree resource : tree.resources) {
1168 CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
1169 @Override
1170 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1171 chk.basicHandler.report(pos, diags.fragment("try.not.applicable.to.type", details));
1172 }
1173 };
1174 ResultInfo twrResult = new ResultInfo(VAL, syms.autoCloseableType, twrContext);
1175 if (resource.hasTag(VARDEF)) {
1176 attribStat(resource, tryEnv);
1177 twrResult.check(resource, resource.type);
1179 //check that resource type cannot throw InterruptedException
1180 checkAutoCloseable(resource.pos(), localEnv, resource.type);
1182 VarSymbol var = (VarSymbol)TreeInfo.symbolFor(resource);
1183 var.setData(ElementKind.RESOURCE_VARIABLE);
1184 } else {
1185 attribTree(resource, tryEnv, twrResult);
1186 }
1187 }
1188 // Attribute body
1189 attribStat(tree.body, tryEnv);
1190 if (isTryWithResource)
1191 tryEnv.info.scope.leave();
1193 // Attribute catch clauses
1194 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
1195 JCCatch c = l.head;
1196 Env<AttrContext> catchEnv =
1197 localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
1198 Type ctype = attribStat(c.param, catchEnv);
1199 if (TreeInfo.isMultiCatch(c)) {
1200 //multi-catch parameter is implicitly marked as final
1201 c.param.sym.flags_field |= FINAL | UNION;
1202 }
1203 if (c.param.sym.kind == Kinds.VAR) {
1204 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
1205 }
1206 chk.checkType(c.param.vartype.pos(),
1207 chk.checkClassType(c.param.vartype.pos(), ctype),
1208 syms.throwableType);
1209 attribStat(c.body, catchEnv);
1210 catchEnv.info.scope.leave();
1211 }
1213 // Attribute finalizer
1214 if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
1216 localEnv.info.scope.leave();
1217 result = null;
1218 }
1220 void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
1221 if (!resource.isErroneous() &&
1222 types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
1223 !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
1224 Symbol close = syms.noSymbol;
1225 boolean prevDeferDiags = log.deferDiagnostics;
1226 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
1227 try {
1228 log.deferDiagnostics = true;
1229 log.deferredDiagnostics = ListBuffer.lb();
1230 close = rs.resolveQualifiedMethod(pos,
1231 env,
1232 resource,
1233 names.close,
1234 List.<Type>nil(),
1235 List.<Type>nil());
1236 }
1237 finally {
1238 log.deferDiagnostics = prevDeferDiags;
1239 log.deferredDiagnostics = prevDeferredDiags;
1240 }
1241 if (close.kind == MTH &&
1242 close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
1243 chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
1244 env.info.lint.isEnabled(LintCategory.TRY)) {
1245 log.warning(LintCategory.TRY, pos, "try.resource.throws.interrupted.exc", resource);
1246 }
1247 }
1248 }
1250 public void visitConditional(JCConditional tree) {
1251 attribExpr(tree.cond, env, syms.booleanType);
1252 attribExpr(tree.truepart, env);
1253 attribExpr(tree.falsepart, env);
1254 result = check(tree,
1255 capture(condType(tree.pos(), tree.cond.type,
1256 tree.truepart.type, tree.falsepart.type)),
1257 VAL, resultInfo);
1258 }
1259 //where
1260 /** Compute the type of a conditional expression, after
1261 * checking that it exists. See Spec 15.25.
1262 *
1263 * @param pos The source position to be used for
1264 * error diagnostics.
1265 * @param condtype The type of the expression's condition.
1266 * @param thentype The type of the expression's then-part.
1267 * @param elsetype The type of the expression's else-part.
1268 */
1269 private Type condType(DiagnosticPosition pos,
1270 Type condtype,
1271 Type thentype,
1272 Type elsetype) {
1273 Type ctype = condType1(pos, condtype, thentype, elsetype);
1275 // If condition and both arms are numeric constants,
1276 // evaluate at compile-time.
1277 return ((condtype.constValue() != null) &&
1278 (thentype.constValue() != null) &&
1279 (elsetype.constValue() != null))
1280 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
1281 : ctype;
1282 }
1283 /** Compute the type of a conditional expression, after
1284 * checking that it exists. Does not take into
1285 * account the special case where condition and both arms
1286 * are constants.
1287 *
1288 * @param pos The source position to be used for error
1289 * diagnostics.
1290 * @param condtype The type of the expression's condition.
1291 * @param thentype The type of the expression's then-part.
1292 * @param elsetype The type of the expression's else-part.
1293 */
1294 private Type condType1(DiagnosticPosition pos, Type condtype,
1295 Type thentype, Type elsetype) {
1296 // If same type, that is the result
1297 if (types.isSameType(thentype, elsetype))
1298 return thentype.baseType();
1300 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1301 ? thentype : types.unboxedType(thentype);
1302 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1303 ? elsetype : types.unboxedType(elsetype);
1305 // Otherwise, if both arms can be converted to a numeric
1306 // type, return the least numeric type that fits both arms
1307 // (i.e. return larger of the two, or return int if one
1308 // arm is short, the other is char).
1309 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1310 // If one arm has an integer subrange type (i.e., byte,
1311 // short, or char), and the other is an integer constant
1312 // that fits into the subrange, return the subrange type.
1313 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1314 types.isAssignable(elseUnboxed, thenUnboxed))
1315 return thenUnboxed.baseType();
1316 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1317 types.isAssignable(thenUnboxed, elseUnboxed))
1318 return elseUnboxed.baseType();
1320 for (int i = BYTE; i < VOID; i++) {
1321 Type candidate = syms.typeOfTag[i];
1322 if (types.isSubtype(thenUnboxed, candidate) &&
1323 types.isSubtype(elseUnboxed, candidate))
1324 return candidate;
1325 }
1326 }
1328 // Those were all the cases that could result in a primitive
1329 if (allowBoxing) {
1330 if (thentype.isPrimitive())
1331 thentype = types.boxedClass(thentype).type;
1332 if (elsetype.isPrimitive())
1333 elsetype = types.boxedClass(elsetype).type;
1334 }
1336 if (types.isSubtype(thentype, elsetype))
1337 return elsetype.baseType();
1338 if (types.isSubtype(elsetype, thentype))
1339 return thentype.baseType();
1341 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1342 log.error(pos, "neither.conditional.subtype",
1343 thentype, elsetype);
1344 return thentype.baseType();
1345 }
1347 // both are known to be reference types. The result is
1348 // lub(thentype,elsetype). This cannot fail, as it will
1349 // always be possible to infer "Object" if nothing better.
1350 return types.lub(thentype.baseType(), elsetype.baseType());
1351 }
1353 public void visitIf(JCIf tree) {
1354 attribExpr(tree.cond, env, syms.booleanType);
1355 attribStat(tree.thenpart, env);
1356 if (tree.elsepart != null)
1357 attribStat(tree.elsepart, env);
1358 chk.checkEmptyIf(tree);
1359 result = null;
1360 }
1362 public void visitExec(JCExpressionStatement tree) {
1363 //a fresh environment is required for 292 inference to work properly ---
1364 //see Infer.instantiatePolymorphicSignatureInstance()
1365 Env<AttrContext> localEnv = env.dup(tree);
1366 attribExpr(tree.expr, localEnv);
1367 result = null;
1368 }
1370 public void visitBreak(JCBreak tree) {
1371 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1372 result = null;
1373 }
1375 public void visitContinue(JCContinue tree) {
1376 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1377 result = null;
1378 }
1379 //where
1380 /** Return the target of a break or continue statement, if it exists,
1381 * report an error if not.
1382 * Note: The target of a labelled break or continue is the
1383 * (non-labelled) statement tree referred to by the label,
1384 * not the tree representing the labelled statement itself.
1385 *
1386 * @param pos The position to be used for error diagnostics
1387 * @param tag The tag of the jump statement. This is either
1388 * Tree.BREAK or Tree.CONTINUE.
1389 * @param label The label of the jump statement, or null if no
1390 * label is given.
1391 * @param env The environment current at the jump statement.
1392 */
1393 private JCTree findJumpTarget(DiagnosticPosition pos,
1394 JCTree.Tag tag,
1395 Name label,
1396 Env<AttrContext> env) {
1397 // Search environments outwards from the point of jump.
1398 Env<AttrContext> env1 = env;
1399 LOOP:
1400 while (env1 != null) {
1401 switch (env1.tree.getTag()) {
1402 case LABELLED:
1403 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1404 if (label == labelled.label) {
1405 // If jump is a continue, check that target is a loop.
1406 if (tag == CONTINUE) {
1407 if (!labelled.body.hasTag(DOLOOP) &&
1408 !labelled.body.hasTag(WHILELOOP) &&
1409 !labelled.body.hasTag(FORLOOP) &&
1410 !labelled.body.hasTag(FOREACHLOOP))
1411 log.error(pos, "not.loop.label", label);
1412 // Found labelled statement target, now go inwards
1413 // to next non-labelled tree.
1414 return TreeInfo.referencedStatement(labelled);
1415 } else {
1416 return labelled;
1417 }
1418 }
1419 break;
1420 case DOLOOP:
1421 case WHILELOOP:
1422 case FORLOOP:
1423 case FOREACHLOOP:
1424 if (label == null) return env1.tree;
1425 break;
1426 case SWITCH:
1427 if (label == null && tag == BREAK) return env1.tree;
1428 break;
1429 case METHODDEF:
1430 case CLASSDEF:
1431 break LOOP;
1432 default:
1433 }
1434 env1 = env1.next;
1435 }
1436 if (label != null)
1437 log.error(pos, "undef.label", label);
1438 else if (tag == CONTINUE)
1439 log.error(pos, "cont.outside.loop");
1440 else
1441 log.error(pos, "break.outside.switch.loop");
1442 return null;
1443 }
1445 public void visitReturn(JCReturn tree) {
1446 // Check that there is an enclosing method which is
1447 // nested within than the enclosing class.
1448 if (env.enclMethod == null ||
1449 env.enclMethod.sym.owner != env.enclClass.sym) {
1450 log.error(tree.pos(), "ret.outside.meth");
1452 } else {
1453 // Attribute return expression, if it exists, and check that
1454 // it conforms to result type of enclosing method.
1455 Symbol m = env.enclMethod.sym;
1456 if (m.type.getReturnType().tag == VOID) {
1457 if (tree.expr != null)
1458 log.error(tree.expr.pos(),
1459 "cant.ret.val.from.meth.decl.void");
1460 } else if (tree.expr == null) {
1461 log.error(tree.pos(), "missing.ret.val");
1462 } else {
1463 attribExpr(tree.expr, env, m.type.getReturnType());
1464 }
1465 }
1466 result = null;
1467 }
1469 public void visitThrow(JCThrow tree) {
1470 attribExpr(tree.expr, env, syms.throwableType);
1471 result = null;
1472 }
1474 public void visitAssert(JCAssert tree) {
1475 attribExpr(tree.cond, env, syms.booleanType);
1476 if (tree.detail != null) {
1477 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1478 }
1479 result = null;
1480 }
1482 /** Visitor method for method invocations.
1483 * NOTE: The method part of an application will have in its type field
1484 * the return type of the method, not the method's type itself!
1485 */
1486 public void visitApply(JCMethodInvocation tree) {
1487 // The local environment of a method application is
1488 // a new environment nested in the current one.
1489 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1491 // The types of the actual method arguments.
1492 List<Type> argtypes;
1494 // The types of the actual method type arguments.
1495 List<Type> typeargtypes = null;
1497 Name methName = TreeInfo.name(tree.meth);
1499 boolean isConstructorCall =
1500 methName == names._this || methName == names._super;
1502 if (isConstructorCall) {
1503 // We are seeing a ...this(...) or ...super(...) call.
1504 // Check that this is the first statement in a constructor.
1505 if (checkFirstConstructorStat(tree, env)) {
1507 // Record the fact
1508 // that this is a constructor call (using isSelfCall).
1509 localEnv.info.isSelfCall = true;
1511 // Attribute arguments, yielding list of argument types.
1512 argtypes = attribArgs(tree.args, localEnv);
1513 typeargtypes = attribTypes(tree.typeargs, localEnv);
1515 // Variable `site' points to the class in which the called
1516 // constructor is defined.
1517 Type site = env.enclClass.sym.type;
1518 if (methName == names._super) {
1519 if (site == syms.objectType) {
1520 log.error(tree.meth.pos(), "no.superclass", site);
1521 site = types.createErrorType(syms.objectType);
1522 } else {
1523 site = types.supertype(site);
1524 }
1525 }
1527 if (site.tag == CLASS) {
1528 Type encl = site.getEnclosingType();
1529 while (encl != null && encl.tag == TYPEVAR)
1530 encl = encl.getUpperBound();
1531 if (encl.tag == CLASS) {
1532 // we are calling a nested class
1534 if (tree.meth.hasTag(SELECT)) {
1535 JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1537 // We are seeing a prefixed call, of the form
1538 // <expr>.super(...).
1539 // Check that the prefix expression conforms
1540 // to the outer instance type of the class.
1541 chk.checkRefType(qualifier.pos(),
1542 attribExpr(qualifier, localEnv,
1543 encl));
1544 } else if (methName == names._super) {
1545 // qualifier omitted; check for existence
1546 // of an appropriate implicit qualifier.
1547 rs.resolveImplicitThis(tree.meth.pos(),
1548 localEnv, site, true);
1549 }
1550 } else if (tree.meth.hasTag(SELECT)) {
1551 log.error(tree.meth.pos(), "illegal.qual.not.icls",
1552 site.tsym);
1553 }
1555 // if we're calling a java.lang.Enum constructor,
1556 // prefix the implicit String and int parameters
1557 if (site.tsym == syms.enumSym && allowEnums)
1558 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1560 // Resolve the called constructor under the assumption
1561 // that we are referring to a superclass instance of the
1562 // current instance (JLS ???).
1563 boolean selectSuperPrev = localEnv.info.selectSuper;
1564 localEnv.info.selectSuper = true;
1565 localEnv.info.varArgs = false;
1566 Symbol sym = rs.resolveConstructor(
1567 tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1568 localEnv.info.selectSuper = selectSuperPrev;
1570 // Set method symbol to resolved constructor...
1571 TreeInfo.setSymbol(tree.meth, sym);
1573 // ...and check that it is legal in the current context.
1574 // (this will also set the tree's type)
1575 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
1576 checkId(tree.meth, site, sym, localEnv, new ResultInfo(MTH, mpt),
1577 tree.varargsElement != null);
1578 }
1579 // Otherwise, `site' is an error type and we do nothing
1580 }
1581 result = tree.type = syms.voidType;
1582 } else {
1583 // Otherwise, we are seeing a regular method call.
1584 // Attribute the arguments, yielding list of argument types, ...
1585 argtypes = attribArgs(tree.args, localEnv);
1586 typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
1588 // ... and attribute the method using as a prototype a methodtype
1589 // whose formal argument types is exactly the list of actual
1590 // arguments (this will also set the method symbol).
1591 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
1592 localEnv.info.varArgs = false;
1593 Type mtype = attribExpr(tree.meth, localEnv, mpt);
1595 // Compute the result type.
1596 Type restype = mtype.getReturnType();
1597 if (restype.tag == WILDCARD)
1598 throw new AssertionError(mtype);
1600 // as a special case, array.clone() has a result that is
1601 // the same as static type of the array being cloned
1602 if (tree.meth.hasTag(SELECT) &&
1603 allowCovariantReturns &&
1604 methName == names.clone &&
1605 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1606 restype = ((JCFieldAccess) tree.meth).selected.type;
1608 // as a special case, x.getClass() has type Class<? extends |X|>
1609 if (allowGenerics &&
1610 methName == names.getClass && tree.args.isEmpty()) {
1611 Type qualifier = (tree.meth.hasTag(SELECT))
1612 ? ((JCFieldAccess) tree.meth).selected.type
1613 : env.enclClass.sym.type;
1614 restype = new
1615 ClassType(restype.getEnclosingType(),
1616 List.<Type>of(new WildcardType(types.erasure(qualifier),
1617 BoundKind.EXTENDS,
1618 syms.boundClass)),
1619 restype.tsym);
1620 }
1622 chk.checkRefTypes(tree.typeargs, typeargtypes);
1624 // Check that value of resulting type is admissible in the
1625 // current context. Also, capture the return type
1626 result = check(tree, capture(restype), VAL, resultInfo);
1628 if (localEnv.info.varArgs)
1629 Assert.check(result.isErroneous() || tree.varargsElement != null);
1630 }
1631 chk.validate(tree.typeargs, localEnv);
1632 }
1633 //where
1634 /** Check that given application node appears as first statement
1635 * in a constructor call.
1636 * @param tree The application node
1637 * @param env The environment current at the application.
1638 */
1639 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1640 JCMethodDecl enclMethod = env.enclMethod;
1641 if (enclMethod != null && enclMethod.name == names.init) {
1642 JCBlock body = enclMethod.body;
1643 if (body.stats.head.hasTag(EXEC) &&
1644 ((JCExpressionStatement) body.stats.head).expr == tree)
1645 return true;
1646 }
1647 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1648 TreeInfo.name(tree.meth));
1649 return false;
1650 }
1652 /** Obtain a method type with given argument types.
1653 */
1654 Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
1655 MethodType mt = new MethodType(argtypes, restype, null, syms.methodClass);
1656 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1657 }
1659 public void visitNewClass(JCNewClass tree) {
1660 Type owntype = types.createErrorType(tree.type);
1662 // The local environment of a class creation is
1663 // a new environment nested in the current one.
1664 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1666 // The anonymous inner class definition of the new expression,
1667 // if one is defined by it.
1668 JCClassDecl cdef = tree.def;
1670 // If enclosing class is given, attribute it, and
1671 // complete class name to be fully qualified
1672 JCExpression clazz = tree.clazz; // Class field following new
1673 JCExpression clazzid = // Identifier in class field
1674 (clazz.hasTag(TYPEAPPLY))
1675 ? ((JCTypeApply) clazz).clazz
1676 : clazz;
1678 JCExpression clazzid1 = clazzid; // The same in fully qualified form
1680 if (tree.encl != null) {
1681 // We are seeing a qualified new, of the form
1682 // <expr>.new C <...> (...) ...
1683 // In this case, we let clazz stand for the name of the
1684 // allocated class C prefixed with the type of the qualifier
1685 // expression, so that we can
1686 // resolve it with standard techniques later. I.e., if
1687 // <expr> has type T, then <expr>.new C <...> (...)
1688 // yields a clazz T.C.
1689 Type encltype = chk.checkRefType(tree.encl.pos(),
1690 attribExpr(tree.encl, env));
1691 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1692 ((JCIdent) clazzid).name);
1693 if (clazz.hasTag(TYPEAPPLY))
1694 clazz = make.at(tree.pos).
1695 TypeApply(clazzid1,
1696 ((JCTypeApply) clazz).arguments);
1697 else
1698 clazz = clazzid1;
1699 }
1701 // Attribute clazz expression and store
1702 // symbol + type back into the attributed tree.
1703 Type clazztype = TreeInfo.isEnumInit(env.tree) ?
1704 attribIdentAsEnumType(env, (JCIdent)clazz) :
1705 attribType(clazz, env);
1707 clazztype = chk.checkDiamond(tree, clazztype);
1708 chk.validate(clazz, localEnv);
1709 if (tree.encl != null) {
1710 // We have to work in this case to store
1711 // symbol + type back into the attributed tree.
1712 tree.clazz.type = clazztype;
1713 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1714 clazzid.type = ((JCIdent) clazzid).sym.type;
1715 if (!clazztype.isErroneous()) {
1716 if (cdef != null && clazztype.tsym.isInterface()) {
1717 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1718 } else if (clazztype.tsym.isStatic()) {
1719 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1720 }
1721 }
1722 } else if (!clazztype.tsym.isInterface() &&
1723 clazztype.getEnclosingType().tag == CLASS) {
1724 // Check for the existence of an apropos outer instance
1725 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1726 }
1728 // Attribute constructor arguments.
1729 List<Type> argtypes = attribArgs(tree.args, localEnv);
1730 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1732 if (TreeInfo.isDiamond(tree) && !clazztype.isErroneous()) {
1733 Pair<Symbol, Type> diamondResult =
1734 attribDiamond(localEnv, tree, clazztype, argtypes, typeargtypes);
1735 tree.clazz.type = types.createErrorType(clazztype);
1736 tree.constructor = diamondResult.fst;
1737 tree.constructorType = diamondResult.snd;
1738 if (!diamondResult.snd.isErroneous()) {
1739 tree.clazz.type = clazztype = diamondResult.snd.getReturnType();
1740 tree.constructorType = types.createMethodTypeWithReturn(diamondResult.snd, syms.voidType);
1741 }
1742 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
1743 }
1745 // If we have made no mistakes in the class type...
1746 if (clazztype.tag == CLASS) {
1747 // Enums may not be instantiated except implicitly
1748 if (allowEnums &&
1749 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1750 (!env.tree.hasTag(VARDEF) ||
1751 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1752 ((JCVariableDecl) env.tree).init != tree))
1753 log.error(tree.pos(), "enum.cant.be.instantiated");
1754 // Check that class is not abstract
1755 if (cdef == null &&
1756 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1757 log.error(tree.pos(), "abstract.cant.be.instantiated",
1758 clazztype.tsym);
1759 } else if (cdef != null && clazztype.tsym.isInterface()) {
1760 // Check that no constructor arguments are given to
1761 // anonymous classes implementing an interface
1762 if (!argtypes.isEmpty())
1763 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1765 if (!typeargtypes.isEmpty())
1766 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1768 // Error recovery: pretend no arguments were supplied.
1769 argtypes = List.nil();
1770 typeargtypes = List.nil();
1771 }
1773 // Resolve the called constructor under the assumption
1774 // that we are referring to a superclass instance of the
1775 // current instance (JLS ???).
1776 else if (!TreeInfo.isDiamond(tree)) {
1777 //the following code alters some of the fields in the current
1778 //AttrContext - hence, the current context must be dup'ed in
1779 //order to avoid downstream failures
1780 Env<AttrContext> rsEnv = localEnv.dup(tree);
1781 rsEnv.info.selectSuper = cdef != null;
1782 rsEnv.info.varArgs = false;
1783 tree.constructor = rs.resolveConstructor(
1784 tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
1785 if (cdef == null) { //do not check twice!
1786 tree.constructorType = checkId(tree,
1787 clazztype,
1788 tree.constructor,
1789 rsEnv,
1790 new ResultInfo(MTH, newMethodTemplate(syms.voidType, argtypes, typeargtypes)),
1791 rsEnv.info.varArgs);
1792 if (rsEnv.info.varArgs)
1793 Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
1794 }
1795 if (tree.def == null &&
1796 !clazztype.isErroneous() &&
1797 clazztype.getTypeArguments().nonEmpty() &&
1798 findDiamonds) {
1799 boolean prevDeferDiags = log.deferDiagnostics;
1800 Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
1801 Type inferred = null;
1802 try {
1803 //disable diamond-related diagnostics
1804 log.deferDiagnostics = true;
1805 log.deferredDiagnostics = ListBuffer.lb();
1806 inferred = attribDiamond(localEnv,
1807 tree,
1808 clazztype,
1809 argtypes,
1810 typeargtypes).snd;
1811 } finally {
1812 log.deferDiagnostics = prevDeferDiags;
1813 log.deferredDiagnostics = prevDeferredDiags;
1814 }
1815 if (!inferred.isErroneous()) {
1816 inferred = inferred.getReturnType();
1817 }
1818 if (inferred != null &&
1819 types.isAssignable(inferred, pt().tag == NONE ? syms.objectType : pt(), Warner.noWarnings)) {
1820 String key = types.isSameType(clazztype, inferred) ?
1821 "diamond.redundant.args" :
1822 "diamond.redundant.args.1";
1823 log.warning(tree.clazz.pos(), key, clazztype, inferred);
1824 }
1825 }
1826 }
1828 if (cdef != null) {
1829 // We are seeing an anonymous class instance creation.
1830 // In this case, the class instance creation
1831 // expression
1832 //
1833 // E.new <typeargs1>C<typargs2>(args) { ... }
1834 //
1835 // is represented internally as
1836 //
1837 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1838 //
1839 // This expression is then *transformed* as follows:
1840 //
1841 // (1) add a STATIC flag to the class definition
1842 // if the current environment is static
1843 // (2) add an extends or implements clause
1844 // (3) add a constructor.
1845 //
1846 // For instance, if C is a class, and ET is the type of E,
1847 // the expression
1848 //
1849 // E.new <typeargs1>C<typargs2>(args) { ... }
1850 //
1851 // is translated to (where X is a fresh name and typarams is the
1852 // parameter list of the super constructor):
1853 //
1854 // new <typeargs1>X(<*nullchk*>E, args) where
1855 // X extends C<typargs2> {
1856 // <typarams> X(ET e, args) {
1857 // e.<typeargs1>super(args)
1858 // }
1859 // ...
1860 // }
1861 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1863 if (clazztype.tsym.isInterface()) {
1864 cdef.implementing = List.of(clazz);
1865 } else {
1866 cdef.extending = clazz;
1867 }
1869 attribStat(cdef, localEnv);
1871 // If an outer instance is given,
1872 // prefix it to the constructor arguments
1873 // and delete it from the new expression
1874 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1875 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1876 argtypes = argtypes.prepend(tree.encl.type);
1877 tree.encl = null;
1878 }
1880 // Reassign clazztype and recompute constructor.
1881 clazztype = cdef.sym.type;
1882 Symbol sym = tree.constructor = rs.resolveConstructor(
1883 tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
1884 Assert.check(sym.kind < AMBIGUOUS);
1885 tree.constructor = sym;
1886 tree.constructorType = checkId(tree,
1887 clazztype,
1888 tree.constructor,
1889 localEnv,
1890 new ResultInfo(VAL, newMethodTemplate(syms.voidType, argtypes, typeargtypes)),
1891 localEnv.info.varArgs);
1892 }
1894 if (tree.constructor != null && tree.constructor.kind == MTH)
1895 owntype = clazztype;
1896 }
1897 result = check(tree, owntype, VAL, resultInfo);
1898 chk.validate(tree.typeargs, localEnv);
1899 }
1901 Pair<Symbol, Type> attribDiamond(Env<AttrContext> env,
1902 final JCNewClass tree,
1903 final Type clazztype,
1904 List<Type> argtypes,
1905 List<Type> typeargtypes) {
1906 if (clazztype.isErroneous() ||
1907 clazztype.isInterface()) {
1908 //if the type of the instance creation expression is erroneous,
1909 //or if it's an interface, or if something prevented us to form a valid
1910 //mapping, return the (possibly erroneous) type unchanged
1911 return new Pair<Symbol, Type>(syms.noSymbol, clazztype);
1912 }
1914 //dup attribution environment and augment the set of inference variables
1915 Env<AttrContext> localEnv = env.dup(tree);
1917 ClassType site = new ClassType(clazztype.getEnclosingType(),
1918 clazztype.tsym.type.getTypeArguments(),
1919 clazztype.tsym);
1921 //if the type of the instance creation expression is a class type
1922 //apply method resolution inference (JLS 15.12.2.7). The return type
1923 //of the resolved constructor will be a partially instantiated type
1924 Symbol constructor = rs.resolveDiamond(tree.pos(),
1925 localEnv,
1926 site,
1927 argtypes,
1928 typeargtypes);
1930 Type constructorType = types.createErrorType(clazztype);
1931 ResultInfo diamondResult = new ResultInfo(MTH, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes), new Check.NestedCheckContext(resultInfo.checkContext) {
1932 @Override
1933 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
1934 enclosingContext.report(tree.clazz,
1935 diags.fragment("cant.apply.diamond.1", diags.fragment("diamond", clazztype.tsym), details));
1936 }
1937 });
1938 constructorType = checkId(tree, site,
1939 constructor,
1940 localEnv,
1941 diamondResult,
1942 localEnv.info.varArgs);
1944 return new Pair<Symbol, Type>(constructor.baseSymbol(), constructorType);
1945 }
1947 /** Make an attributed null check tree.
1948 */
1949 public JCExpression makeNullCheck(JCExpression arg) {
1950 // optimization: X.this is never null; skip null check
1951 Name name = TreeInfo.name(arg);
1952 if (name == names._this || name == names._super) return arg;
1954 JCTree.Tag optag = NULLCHK;
1955 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1956 tree.operator = syms.nullcheck;
1957 tree.type = arg.type;
1958 return tree;
1959 }
1961 public void visitNewArray(JCNewArray tree) {
1962 Type owntype = types.createErrorType(tree.type);
1963 Type elemtype;
1964 if (tree.elemtype != null) {
1965 elemtype = attribType(tree.elemtype, env);
1966 chk.validate(tree.elemtype, env);
1967 owntype = elemtype;
1968 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1969 attribExpr(l.head, env, syms.intType);
1970 owntype = new ArrayType(owntype, syms.arrayClass);
1971 }
1972 } else {
1973 // we are seeing an untyped aggregate { ... }
1974 // this is allowed only if the prototype is an array
1975 if (pt().tag == ARRAY) {
1976 elemtype = types.elemtype(pt());
1977 } else {
1978 if (pt().tag != ERROR) {
1979 log.error(tree.pos(), "illegal.initializer.for.type",
1980 pt());
1981 }
1982 elemtype = types.createErrorType(pt());
1983 }
1984 }
1985 if (tree.elems != null) {
1986 attribExprs(tree.elems, env, elemtype);
1987 owntype = new ArrayType(elemtype, syms.arrayClass);
1988 }
1989 if (!types.isReifiable(elemtype))
1990 log.error(tree.pos(), "generic.array.creation");
1991 result = check(tree, owntype, VAL, resultInfo);
1992 }
1994 @Override
1995 public void visitLambda(JCLambda that) {
1996 throw new UnsupportedOperationException("Lambda expression not supported yet");
1997 }
1999 @Override
2000 public void visitReference(JCMemberReference that) {
2001 throw new UnsupportedOperationException("Member references not supported yet");
2002 }
2004 public void visitParens(JCParens tree) {
2005 Type owntype = attribTree(tree.expr, env, resultInfo);
2006 result = check(tree, owntype, pkind(), resultInfo);
2007 Symbol sym = TreeInfo.symbol(tree);
2008 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
2009 log.error(tree.pos(), "illegal.start.of.type");
2010 }
2012 public void visitAssign(JCAssign tree) {
2013 Type owntype = attribTree(tree.lhs, env.dup(tree), varInfo);
2014 Type capturedType = capture(owntype);
2015 attribExpr(tree.rhs, env, owntype);
2016 result = check(tree, capturedType, VAL, resultInfo);
2017 }
2019 public void visitAssignop(JCAssignOp tree) {
2020 // Attribute arguments.
2021 Type owntype = attribTree(tree.lhs, env, varInfo);
2022 Type operand = attribExpr(tree.rhs, env);
2023 // Find operator.
2024 Symbol operator = tree.operator = rs.resolveBinaryOperator(
2025 tree.pos(), tree.getTag().noAssignOp(), env,
2026 owntype, operand);
2028 if (operator.kind == MTH &&
2029 !owntype.isErroneous() &&
2030 !operand.isErroneous()) {
2031 chk.checkOperator(tree.pos(),
2032 (OperatorSymbol)operator,
2033 tree.getTag().noAssignOp(),
2034 owntype,
2035 operand);
2036 chk.checkDivZero(tree.rhs.pos(), operator, operand);
2037 chk.checkCastable(tree.rhs.pos(),
2038 operator.type.getReturnType(),
2039 owntype);
2040 }
2041 result = check(tree, owntype, VAL, resultInfo);
2042 }
2044 public void visitUnary(JCUnary tree) {
2045 // Attribute arguments.
2046 Type argtype = (tree.getTag().isIncOrDecUnaryOp())
2047 ? attribTree(tree.arg, env, varInfo)
2048 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
2050 // Find operator.
2051 Symbol operator = tree.operator =
2052 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
2054 Type owntype = types.createErrorType(tree.type);
2055 if (operator.kind == MTH &&
2056 !argtype.isErroneous()) {
2057 owntype = (tree.getTag().isIncOrDecUnaryOp())
2058 ? tree.arg.type
2059 : operator.type.getReturnType();
2060 int opc = ((OperatorSymbol)operator).opcode;
2062 // If the argument is constant, fold it.
2063 if (argtype.constValue() != null) {
2064 Type ctype = cfolder.fold1(opc, argtype);
2065 if (ctype != null) {
2066 owntype = cfolder.coerce(ctype, owntype);
2068 // Remove constant types from arguments to
2069 // conserve space. The parser will fold concatenations
2070 // of string literals; the code here also
2071 // gets rid of intermediate results when some of the
2072 // operands are constant identifiers.
2073 if (tree.arg.type.tsym == syms.stringType.tsym) {
2074 tree.arg.type = syms.stringType;
2075 }
2076 }
2077 }
2078 }
2079 result = check(tree, owntype, VAL, resultInfo);
2080 }
2082 public void visitBinary(JCBinary tree) {
2083 // Attribute arguments.
2084 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
2085 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
2087 // Find operator.
2088 Symbol operator = tree.operator =
2089 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
2091 Type owntype = types.createErrorType(tree.type);
2092 if (operator.kind == MTH &&
2093 !left.isErroneous() &&
2094 !right.isErroneous()) {
2095 owntype = operator.type.getReturnType();
2096 int opc = chk.checkOperator(tree.lhs.pos(),
2097 (OperatorSymbol)operator,
2098 tree.getTag(),
2099 left,
2100 right);
2102 // If both arguments are constants, fold them.
2103 if (left.constValue() != null && right.constValue() != null) {
2104 Type ctype = cfolder.fold2(opc, left, right);
2105 if (ctype != null) {
2106 owntype = cfolder.coerce(ctype, owntype);
2108 // Remove constant types from arguments to
2109 // conserve space. The parser will fold concatenations
2110 // of string literals; the code here also
2111 // gets rid of intermediate results when some of the
2112 // operands are constant identifiers.
2113 if (tree.lhs.type.tsym == syms.stringType.tsym) {
2114 tree.lhs.type = syms.stringType;
2115 }
2116 if (tree.rhs.type.tsym == syms.stringType.tsym) {
2117 tree.rhs.type = syms.stringType;
2118 }
2119 }
2120 }
2122 // Check that argument types of a reference ==, != are
2123 // castable to each other, (JLS???).
2124 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
2125 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
2126 log.error(tree.pos(), "incomparable.types", left, right);
2127 }
2128 }
2130 chk.checkDivZero(tree.rhs.pos(), operator, right);
2131 }
2132 result = check(tree, owntype, VAL, resultInfo);
2133 }
2135 public void visitTypeCast(JCTypeCast tree) {
2136 Type clazztype = attribType(tree.clazz, env);
2137 chk.validate(tree.clazz, env, false);
2138 //a fresh environment is required for 292 inference to work properly ---
2139 //see Infer.instantiatePolymorphicSignatureInstance()
2140 Env<AttrContext> localEnv = env.dup(tree);
2141 Type exprtype = attribExpr(tree.expr, localEnv, Infer.anyPoly);
2142 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2143 if (exprtype.constValue() != null)
2144 owntype = cfolder.coerce(exprtype, owntype);
2145 result = check(tree, capture(owntype), VAL, resultInfo);
2146 chk.checkRedundantCast(localEnv, tree);
2147 }
2149 public void visitTypeTest(JCInstanceOf tree) {
2150 Type exprtype = chk.checkNullOrRefType(
2151 tree.expr.pos(), attribExpr(tree.expr, env));
2152 Type clazztype = chk.checkReifiableReferenceType(
2153 tree.clazz.pos(), attribType(tree.clazz, env));
2154 chk.validate(tree.clazz, env, false);
2155 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
2156 result = check(tree, syms.booleanType, VAL, resultInfo);
2157 }
2159 public void visitIndexed(JCArrayAccess tree) {
2160 Type owntype = types.createErrorType(tree.type);
2161 Type atype = attribExpr(tree.indexed, env);
2162 attribExpr(tree.index, env, syms.intType);
2163 if (types.isArray(atype))
2164 owntype = types.elemtype(atype);
2165 else if (atype.tag != ERROR)
2166 log.error(tree.pos(), "array.req.but.found", atype);
2167 if ((pkind() & VAR) == 0) owntype = capture(owntype);
2168 result = check(tree, owntype, VAR, resultInfo);
2169 }
2171 public void visitIdent(JCIdent tree) {
2172 Symbol sym;
2173 boolean varArgs = false;
2175 // Find symbol
2176 if (pt().tag == METHOD || pt().tag == FORALL) {
2177 // If we are looking for a method, the prototype `pt' will be a
2178 // method type with the type of the call's arguments as parameters.
2179 env.info.varArgs = false;
2180 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
2181 varArgs = env.info.varArgs;
2182 } else if (tree.sym != null && tree.sym.kind != VAR) {
2183 sym = tree.sym;
2184 } else {
2185 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
2186 }
2187 tree.sym = sym;
2189 // (1) Also find the environment current for the class where
2190 // sym is defined (`symEnv').
2191 // Only for pre-tiger versions (1.4 and earlier):
2192 // (2) Also determine whether we access symbol out of an anonymous
2193 // class in a this or super call. This is illegal for instance
2194 // members since such classes don't carry a this$n link.
2195 // (`noOuterThisPath').
2196 Env<AttrContext> symEnv = env;
2197 boolean noOuterThisPath = false;
2198 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
2199 (sym.kind & (VAR | MTH | TYP)) != 0 &&
2200 sym.owner.kind == TYP &&
2201 tree.name != names._this && tree.name != names._super) {
2203 // Find environment in which identifier is defined.
2204 while (symEnv.outer != null &&
2205 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
2206 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
2207 noOuterThisPath = !allowAnonOuterThis;
2208 symEnv = symEnv.outer;
2209 }
2210 }
2212 // If symbol is a variable, ...
2213 if (sym.kind == VAR) {
2214 VarSymbol v = (VarSymbol)sym;
2216 // ..., evaluate its initializer, if it has one, and check for
2217 // illegal forward reference.
2218 checkInit(tree, env, v, false);
2220 // If we are expecting a variable (as opposed to a value), check
2221 // that the variable is assignable in the current environment.
2222 if (pkind() == VAR)
2223 checkAssignable(tree.pos(), v, null, env);
2224 }
2226 // In a constructor body,
2227 // if symbol is a field or instance method, check that it is
2228 // not accessed before the supertype constructor is called.
2229 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
2230 (sym.kind & (VAR | MTH)) != 0 &&
2231 sym.owner.kind == TYP &&
2232 (sym.flags() & STATIC) == 0) {
2233 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
2234 }
2235 Env<AttrContext> env1 = env;
2236 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
2237 // If the found symbol is inaccessible, then it is
2238 // accessed through an enclosing instance. Locate this
2239 // enclosing instance:
2240 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
2241 env1 = env1.outer;
2242 }
2243 result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo, varArgs);
2244 }
2246 public void visitSelect(JCFieldAccess tree) {
2247 // Determine the expected kind of the qualifier expression.
2248 int skind = 0;
2249 if (tree.name == names._this || tree.name == names._super ||
2250 tree.name == names._class)
2251 {
2252 skind = TYP;
2253 } else {
2254 if ((pkind() & PCK) != 0) skind = skind | PCK;
2255 if ((pkind() & TYP) != 0) skind = skind | TYP | PCK;
2256 if ((pkind() & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
2257 }
2259 // Attribute the qualifier expression, and determine its symbol (if any).
2260 Type site = attribTree(tree.selected, env, new ResultInfo(skind, Infer.anyPoly));
2261 if ((pkind() & (PCK | TYP)) == 0)
2262 site = capture(site); // Capture field access
2264 // don't allow T.class T[].class, etc
2265 if (skind == TYP) {
2266 Type elt = site;
2267 while (elt.tag == ARRAY)
2268 elt = ((ArrayType)elt).elemtype;
2269 if (elt.tag == TYPEVAR) {
2270 log.error(tree.pos(), "type.var.cant.be.deref");
2271 result = types.createErrorType(tree.type);
2272 return;
2273 }
2274 }
2276 // If qualifier symbol is a type or `super', assert `selectSuper'
2277 // for the selection. This is relevant for determining whether
2278 // protected symbols are accessible.
2279 Symbol sitesym = TreeInfo.symbol(tree.selected);
2280 boolean selectSuperPrev = env.info.selectSuper;
2281 env.info.selectSuper =
2282 sitesym != null &&
2283 sitesym.name == names._super;
2285 // Determine the symbol represented by the selection.
2286 env.info.varArgs = false;
2287 Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
2288 if (sym.exists() && !isType(sym) && (pkind() & (PCK | TYP)) != 0) {
2289 site = capture(site);
2290 sym = selectSym(tree, sitesym, site, env, resultInfo);
2291 }
2292 boolean varArgs = env.info.varArgs;
2293 tree.sym = sym;
2295 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
2296 while (site.tag == TYPEVAR) site = site.getUpperBound();
2297 site = capture(site);
2298 }
2300 // If that symbol is a variable, ...
2301 if (sym.kind == VAR) {
2302 VarSymbol v = (VarSymbol)sym;
2304 // ..., evaluate its initializer, if it has one, and check for
2305 // illegal forward reference.
2306 checkInit(tree, env, v, true);
2308 // If we are expecting a variable (as opposed to a value), check
2309 // that the variable is assignable in the current environment.
2310 if (pkind() == VAR)
2311 checkAssignable(tree.pos(), v, tree.selected, env);
2312 }
2314 if (sitesym != null &&
2315 sitesym.kind == VAR &&
2316 ((VarSymbol)sitesym).isResourceVariable() &&
2317 sym.kind == MTH &&
2318 sym.name.equals(names.close) &&
2319 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
2320 env.info.lint.isEnabled(LintCategory.TRY)) {
2321 log.warning(LintCategory.TRY, tree, "try.explicit.close.call");
2322 }
2324 // Disallow selecting a type from an expression
2325 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
2326 tree.type = check(tree.selected, pt(),
2327 sitesym == null ? VAL : sitesym.kind, new ResultInfo(TYP|PCK, pt()));
2328 }
2330 if (isType(sitesym)) {
2331 if (sym.name == names._this) {
2332 // If `C' is the currently compiled class, check that
2333 // C.this' does not appear in a call to a super(...)
2334 if (env.info.isSelfCall &&
2335 site.tsym == env.enclClass.sym) {
2336 chk.earlyRefError(tree.pos(), sym);
2337 }
2338 } else {
2339 // Check if type-qualified fields or methods are static (JLS)
2340 if ((sym.flags() & STATIC) == 0 &&
2341 sym.name != names._super &&
2342 (sym.kind == VAR || sym.kind == MTH)) {
2343 rs.access(rs.new StaticError(sym),
2344 tree.pos(), site, sym.name, true);
2345 }
2346 }
2347 } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
2348 // If the qualified item is not a type and the selected item is static, report
2349 // a warning. Make allowance for the class of an array type e.g. Object[].class)
2350 chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
2351 }
2353 // If we are selecting an instance member via a `super', ...
2354 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
2356 // Check that super-qualified symbols are not abstract (JLS)
2357 rs.checkNonAbstract(tree.pos(), sym);
2359 if (site.isRaw()) {
2360 // Determine argument types for site.
2361 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
2362 if (site1 != null) site = site1;
2363 }
2364 }
2366 env.info.selectSuper = selectSuperPrev;
2367 result = checkId(tree, site, sym, env, resultInfo, varArgs);
2368 }
2369 //where
2370 /** Determine symbol referenced by a Select expression,
2371 *
2372 * @param tree The select tree.
2373 * @param site The type of the selected expression,
2374 * @param env The current environment.
2375 * @param resultInfo The current result.
2376 */
2377 private Symbol selectSym(JCFieldAccess tree,
2378 Symbol location,
2379 Type site,
2380 Env<AttrContext> env,
2381 ResultInfo resultInfo) {
2382 DiagnosticPosition pos = tree.pos();
2383 Name name = tree.name;
2384 switch (site.tag) {
2385 case PACKAGE:
2386 return rs.access(
2387 rs.findIdentInPackage(env, site.tsym, name, resultInfo.pkind),
2388 pos, location, site, name, true);
2389 case ARRAY:
2390 case CLASS:
2391 if (resultInfo.pt.tag == METHOD || resultInfo.pt.tag == FORALL) {
2392 return rs.resolveQualifiedMethod(
2393 pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
2394 } else if (name == names._this || name == names._super) {
2395 return rs.resolveSelf(pos, env, site.tsym, name);
2396 } else if (name == names._class) {
2397 // In this case, we have already made sure in
2398 // visitSelect that qualifier expression is a type.
2399 Type t = syms.classType;
2400 List<Type> typeargs = allowGenerics
2401 ? List.of(types.erasure(site))
2402 : List.<Type>nil();
2403 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
2404 return new VarSymbol(
2405 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2406 } else {
2407 // We are seeing a plain identifier as selector.
2408 Symbol sym = rs.findIdentInType(env, site, name, resultInfo.pkind);
2409 if ((resultInfo.pkind & ERRONEOUS) == 0)
2410 sym = rs.access(sym, pos, location, site, name, true);
2411 return sym;
2412 }
2413 case WILDCARD:
2414 throw new AssertionError(tree);
2415 case TYPEVAR:
2416 // Normally, site.getUpperBound() shouldn't be null.
2417 // It should only happen during memberEnter/attribBase
2418 // when determining the super type which *must* beac
2419 // done before attributing the type variables. In
2420 // other words, we are seeing this illegal program:
2421 // class B<T> extends A<T.foo> {}
2422 Symbol sym = (site.getUpperBound() != null)
2423 ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
2424 : null;
2425 if (sym == null) {
2426 log.error(pos, "type.var.cant.be.deref");
2427 return syms.errSymbol;
2428 } else {
2429 Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
2430 rs.new AccessError(env, site, sym) :
2431 sym;
2432 rs.access(sym2, pos, location, site, name, true);
2433 return sym;
2434 }
2435 case ERROR:
2436 // preserve identifier names through errors
2437 return types.createErrorType(name, site.tsym, site).tsym;
2438 default:
2439 // The qualifier expression is of a primitive type -- only
2440 // .class is allowed for these.
2441 if (name == names._class) {
2442 // In this case, we have already made sure in Select that
2443 // qualifier expression is a type.
2444 Type t = syms.classType;
2445 Type arg = types.boxedClass(site).type;
2446 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2447 return new VarSymbol(
2448 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2449 } else {
2450 log.error(pos, "cant.deref", site);
2451 return syms.errSymbol;
2452 }
2453 }
2454 }
2456 /** Determine type of identifier or select expression and check that
2457 * (1) the referenced symbol is not deprecated
2458 * (2) the symbol's type is safe (@see checkSafe)
2459 * (3) if symbol is a variable, check that its type and kind are
2460 * compatible with the prototype and protokind.
2461 * (4) if symbol is an instance field of a raw type,
2462 * which is being assigned to, issue an unchecked warning if its
2463 * type changes under erasure.
2464 * (5) if symbol is an instance method of a raw type, issue an
2465 * unchecked warning if its argument types change under erasure.
2466 * If checks succeed:
2467 * If symbol is a constant, return its constant type
2468 * else if symbol is a method, return its result type
2469 * otherwise return its type.
2470 * Otherwise return errType.
2471 *
2472 * @param tree The syntax tree representing the identifier
2473 * @param site If this is a select, the type of the selected
2474 * expression, otherwise the type of the current class.
2475 * @param sym The symbol representing the identifier.
2476 * @param env The current environment.
2477 * @param resultInfo The expected result
2478 */
2479 Type checkId(JCTree tree,
2480 Type site,
2481 Symbol sym,
2482 Env<AttrContext> env,
2483 ResultInfo resultInfo,
2484 boolean useVarargs) {
2485 if (resultInfo.pt.isErroneous()) return types.createErrorType(site);
2486 Type owntype; // The computed type of this identifier occurrence.
2487 switch (sym.kind) {
2488 case TYP:
2489 // For types, the computed type equals the symbol's type,
2490 // except for two situations:
2491 owntype = sym.type;
2492 if (owntype.tag == CLASS) {
2493 Type ownOuter = owntype.getEnclosingType();
2495 // (a) If the symbol's type is parameterized, erase it
2496 // because no type parameters were given.
2497 // We recover generic outer type later in visitTypeApply.
2498 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2499 owntype = types.erasure(owntype);
2500 }
2502 // (b) If the symbol's type is an inner class, then
2503 // we have to interpret its outer type as a superclass
2504 // of the site type. Example:
2505 //
2506 // class Tree<A> { class Visitor { ... } }
2507 // class PointTree extends Tree<Point> { ... }
2508 // ...PointTree.Visitor...
2509 //
2510 // Then the type of the last expression above is
2511 // Tree<Point>.Visitor.
2512 else if (ownOuter.tag == CLASS && site != ownOuter) {
2513 Type normOuter = site;
2514 if (normOuter.tag == CLASS)
2515 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2516 if (normOuter == null) // perhaps from an import
2517 normOuter = types.erasure(ownOuter);
2518 if (normOuter != ownOuter)
2519 owntype = new ClassType(
2520 normOuter, List.<Type>nil(), owntype.tsym);
2521 }
2522 }
2523 break;
2524 case VAR:
2525 VarSymbol v = (VarSymbol)sym;
2526 // Test (4): if symbol is an instance field of a raw type,
2527 // which is being assigned to, issue an unchecked warning if
2528 // its type changes under erasure.
2529 if (allowGenerics &&
2530 resultInfo.pkind == VAR &&
2531 v.owner.kind == TYP &&
2532 (v.flags() & STATIC) == 0 &&
2533 (site.tag == CLASS || site.tag == TYPEVAR)) {
2534 Type s = types.asOuterSuper(site, v.owner);
2535 if (s != null &&
2536 s.isRaw() &&
2537 !types.isSameType(v.type, v.erasure(types))) {
2538 chk.warnUnchecked(tree.pos(),
2539 "unchecked.assign.to.var",
2540 v, s);
2541 }
2542 }
2543 // The computed type of a variable is the type of the
2544 // variable symbol, taken as a member of the site type.
2545 owntype = (sym.owner.kind == TYP &&
2546 sym.name != names._this && sym.name != names._super)
2547 ? types.memberType(site, sym)
2548 : sym.type;
2550 // If the variable is a constant, record constant value in
2551 // computed type.
2552 if (v.getConstValue() != null && isStaticReference(tree))
2553 owntype = owntype.constType(v.getConstValue());
2555 if (resultInfo.pkind == VAL) {
2556 owntype = capture(owntype); // capture "names as expressions"
2557 }
2558 break;
2559 case MTH: {
2560 owntype = checkMethod(site, sym,
2561 new ResultInfo(VAL, resultInfo.pt.getReturnType(), resultInfo.checkContext),
2562 env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
2563 resultInfo.pt.getTypeArguments(), env.info.varArgs);
2564 break;
2565 }
2566 case PCK: case ERR:
2567 owntype = sym.type;
2568 break;
2569 default:
2570 throw new AssertionError("unexpected kind: " + sym.kind +
2571 " in tree " + tree);
2572 }
2574 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2575 // (for constructors, the error was given when the constructor was
2576 // resolved)
2578 if (sym.name != names.init) {
2579 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
2580 chk.checkSunAPI(tree.pos(), sym);
2581 }
2583 // Test (3): if symbol is a variable, check that its type and
2584 // kind are compatible with the prototype and protokind.
2585 return check(tree, owntype, sym.kind, resultInfo);
2586 }
2588 /** Check that variable is initialized and evaluate the variable's
2589 * initializer, if not yet done. Also check that variable is not
2590 * referenced before it is defined.
2591 * @param tree The tree making up the variable reference.
2592 * @param env The current environment.
2593 * @param v The variable's symbol.
2594 */
2595 private void checkInit(JCTree tree,
2596 Env<AttrContext> env,
2597 VarSymbol v,
2598 boolean onlyWarning) {
2599 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2600 // tree.pos + " " + v.pos + " " +
2601 // Resolve.isStatic(env));//DEBUG
2603 // A forward reference is diagnosed if the declaration position
2604 // of the variable is greater than the current tree position
2605 // and the tree and variable definition occur in the same class
2606 // definition. Note that writes don't count as references.
2607 // This check applies only to class and instance
2608 // variables. Local variables follow different scope rules,
2609 // and are subject to definite assignment checking.
2610 if ((env.info.enclVar == v || v.pos > tree.pos) &&
2611 v.owner.kind == TYP &&
2612 canOwnInitializer(owner(env)) &&
2613 v.owner == env.info.scope.owner.enclClass() &&
2614 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2615 (!env.tree.hasTag(ASSIGN) ||
2616 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2617 String suffix = (env.info.enclVar == v) ?
2618 "self.ref" : "forward.ref";
2619 if (!onlyWarning || isStaticEnumField(v)) {
2620 log.error(tree.pos(), "illegal." + suffix);
2621 } else if (useBeforeDeclarationWarning) {
2622 log.warning(tree.pos(), suffix, v);
2623 }
2624 }
2626 v.getConstValue(); // ensure initializer is evaluated
2628 checkEnumInitializer(tree, env, v);
2629 }
2631 /**
2632 * Check for illegal references to static members of enum. In
2633 * an enum type, constructors and initializers may not
2634 * reference its static members unless they are constant.
2635 *
2636 * @param tree The tree making up the variable reference.
2637 * @param env The current environment.
2638 * @param v The variable's symbol.
2639 * @jls section 8.9 Enums
2640 */
2641 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2642 // JLS:
2643 //
2644 // "It is a compile-time error to reference a static field
2645 // of an enum type that is not a compile-time constant
2646 // (15.28) from constructors, instance initializer blocks,
2647 // or instance variable initializer expressions of that
2648 // type. It is a compile-time error for the constructors,
2649 // instance initializer blocks, or instance variable
2650 // initializer expressions of an enum constant e to refer
2651 // to itself or to an enum constant of the same type that
2652 // is declared to the right of e."
2653 if (isStaticEnumField(v)) {
2654 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2656 if (enclClass == null || enclClass.owner == null)
2657 return;
2659 // See if the enclosing class is the enum (or a
2660 // subclass thereof) declaring v. If not, this
2661 // reference is OK.
2662 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2663 return;
2665 // If the reference isn't from an initializer, then
2666 // the reference is OK.
2667 if (!Resolve.isInitializer(env))
2668 return;
2670 log.error(tree.pos(), "illegal.enum.static.ref");
2671 }
2672 }
2674 /** Is the given symbol a static, non-constant field of an Enum?
2675 * Note: enum literals should not be regarded as such
2676 */
2677 private boolean isStaticEnumField(VarSymbol v) {
2678 return Flags.isEnum(v.owner) &&
2679 Flags.isStatic(v) &&
2680 !Flags.isConstant(v) &&
2681 v.name != names._class;
2682 }
2684 /** Can the given symbol be the owner of code which forms part
2685 * if class initialization? This is the case if the symbol is
2686 * a type or field, or if the symbol is the synthetic method.
2687 * owning a block.
2688 */
2689 private boolean canOwnInitializer(Symbol sym) {
2690 return
2691 (sym.kind & (VAR | TYP)) != 0 ||
2692 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2693 }
2695 Warner noteWarner = new Warner();
2697 /**
2698 * Check that method arguments conform to its instantiation.
2699 **/
2700 public Type checkMethod(Type site,
2701 Symbol sym,
2702 ResultInfo resultInfo,
2703 Env<AttrContext> env,
2704 final List<JCExpression> argtrees,
2705 List<Type> argtypes,
2706 List<Type> typeargtypes,
2707 boolean useVarargs) {
2708 // Test (5): if symbol is an instance method of a raw type, issue
2709 // an unchecked warning if its argument types change under erasure.
2710 if (allowGenerics &&
2711 (sym.flags() & STATIC) == 0 &&
2712 (site.tag == CLASS || site.tag == TYPEVAR)) {
2713 Type s = types.asOuterSuper(site, sym.owner);
2714 if (s != null && s.isRaw() &&
2715 !types.isSameTypes(sym.type.getParameterTypes(),
2716 sym.erasure(types).getParameterTypes())) {
2717 chk.warnUnchecked(env.tree.pos(),
2718 "unchecked.call.mbr.of.raw.type",
2719 sym, s);
2720 }
2721 }
2723 // Compute the identifier's instantiated type.
2724 // For methods, we need to compute the instance type by
2725 // Resolve.instantiate from the symbol's type as well as
2726 // any type arguments and value arguments.
2727 noteWarner.clear();
2728 try {
2729 Type owntype = rs.rawInstantiate(
2730 env,
2731 site,
2732 sym,
2733 resultInfo,
2734 argtypes,
2735 typeargtypes,
2736 allowBoxing,
2737 useVarargs,
2738 noteWarner);
2740 return chk.checkMethod(owntype, sym, env, argtrees, argtypes, useVarargs,
2741 noteWarner.hasNonSilentLint(LintCategory.UNCHECKED));
2742 } catch (Infer.InferenceException ex) {
2743 //invalid target type - propagate exception outwards or report error
2744 //depending on the current check context
2745 resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
2746 return types.createErrorType(site);
2747 } catch (Resolve.InapplicableMethodException ex) {
2748 Assert.error();
2749 return null;
2750 }
2751 }
2753 public void visitLiteral(JCLiteral tree) {
2754 result = check(
2755 tree, litType(tree.typetag).constType(tree.value), VAL, resultInfo);
2756 }
2757 //where
2758 /** Return the type of a literal with given type tag.
2759 */
2760 Type litType(int tag) {
2761 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2762 }
2764 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2765 result = check(tree, syms.typeOfTag[tree.typetag], TYP, resultInfo);
2766 }
2768 public void visitTypeArray(JCArrayTypeTree tree) {
2769 Type etype = attribType(tree.elemtype, env);
2770 Type type = new ArrayType(etype, syms.arrayClass);
2771 result = check(tree, type, TYP, resultInfo);
2772 }
2774 /** Visitor method for parameterized types.
2775 * Bound checking is left until later, since types are attributed
2776 * before supertype structure is completely known
2777 */
2778 public void visitTypeApply(JCTypeApply tree) {
2779 Type owntype = types.createErrorType(tree.type);
2781 // Attribute functor part of application and make sure it's a class.
2782 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2784 // Attribute type parameters
2785 List<Type> actuals = attribTypes(tree.arguments, env);
2787 if (clazztype.tag == CLASS) {
2788 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2789 if (actuals.isEmpty()) //diamond
2790 actuals = formals;
2792 if (actuals.length() == formals.length()) {
2793 List<Type> a = actuals;
2794 List<Type> f = formals;
2795 while (a.nonEmpty()) {
2796 a.head = a.head.withTypeVar(f.head);
2797 a = a.tail;
2798 f = f.tail;
2799 }
2800 // Compute the proper generic outer
2801 Type clazzOuter = clazztype.getEnclosingType();
2802 if (clazzOuter.tag == CLASS) {
2803 Type site;
2804 JCExpression clazz = TreeInfo.typeIn(tree.clazz);
2805 if (clazz.hasTag(IDENT)) {
2806 site = env.enclClass.sym.type;
2807 } else if (clazz.hasTag(SELECT)) {
2808 site = ((JCFieldAccess) clazz).selected.type;
2809 } else throw new AssertionError(""+tree);
2810 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2811 if (site.tag == CLASS)
2812 site = types.asOuterSuper(site, clazzOuter.tsym);
2813 if (site == null)
2814 site = types.erasure(clazzOuter);
2815 clazzOuter = site;
2816 }
2817 }
2818 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2819 } else {
2820 if (formals.length() != 0) {
2821 log.error(tree.pos(), "wrong.number.type.args",
2822 Integer.toString(formals.length()));
2823 } else {
2824 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2825 }
2826 owntype = types.createErrorType(tree.type);
2827 }
2828 }
2829 result = check(tree, owntype, TYP, resultInfo);
2830 }
2832 public void visitTypeUnion(JCTypeUnion tree) {
2833 ListBuffer<Type> multicatchTypes = ListBuffer.lb();
2834 ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
2835 for (JCExpression typeTree : tree.alternatives) {
2836 Type ctype = attribType(typeTree, env);
2837 ctype = chk.checkType(typeTree.pos(),
2838 chk.checkClassType(typeTree.pos(), ctype),
2839 syms.throwableType);
2840 if (!ctype.isErroneous()) {
2841 //check that alternatives of a union type are pairwise
2842 //unrelated w.r.t. subtyping
2843 if (chk.intersects(ctype, multicatchTypes.toList())) {
2844 for (Type t : multicatchTypes) {
2845 boolean sub = types.isSubtype(ctype, t);
2846 boolean sup = types.isSubtype(t, ctype);
2847 if (sub || sup) {
2848 //assume 'a' <: 'b'
2849 Type a = sub ? ctype : t;
2850 Type b = sub ? t : ctype;
2851 log.error(typeTree.pos(), "multicatch.types.must.be.disjoint", a, b);
2852 }
2853 }
2854 }
2855 multicatchTypes.append(ctype);
2856 if (all_multicatchTypes != null)
2857 all_multicatchTypes.append(ctype);
2858 } else {
2859 if (all_multicatchTypes == null) {
2860 all_multicatchTypes = ListBuffer.lb();
2861 all_multicatchTypes.appendList(multicatchTypes);
2862 }
2863 all_multicatchTypes.append(ctype);
2864 }
2865 }
2866 Type t = check(tree, types.lub(multicatchTypes.toList()), TYP, resultInfo);
2867 if (t.tag == CLASS) {
2868 List<Type> alternatives =
2869 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
2870 t = new UnionClassType((ClassType) t, alternatives);
2871 }
2872 tree.type = result = t;
2873 }
2875 public void visitTypeParameter(JCTypeParameter tree) {
2876 TypeVar a = (TypeVar)tree.type;
2877 Set<Type> boundSet = new HashSet<Type>();
2878 if (a.bound.isErroneous())
2879 return;
2880 List<Type> bs = types.getBounds(a);
2881 if (tree.bounds.nonEmpty()) {
2882 // accept class or interface or typevar as first bound.
2883 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2884 boundSet.add(types.erasure(b));
2885 if (b.isErroneous()) {
2886 a.bound = b;
2887 }
2888 else if (b.tag == TYPEVAR) {
2889 // if first bound was a typevar, do not accept further bounds.
2890 if (tree.bounds.tail.nonEmpty()) {
2891 log.error(tree.bounds.tail.head.pos(),
2892 "type.var.may.not.be.followed.by.other.bounds");
2893 tree.bounds = List.of(tree.bounds.head);
2894 a.bound = bs.head;
2895 }
2896 } else {
2897 // if first bound was a class or interface, accept only interfaces
2898 // as further bounds.
2899 for (JCExpression bound : tree.bounds.tail) {
2900 bs = bs.tail;
2901 Type i = checkBase(bs.head, bound, env, false, true, false);
2902 if (i.isErroneous())
2903 a.bound = i;
2904 else if (i.tag == CLASS)
2905 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
2906 }
2907 }
2908 }
2909 bs = types.getBounds(a);
2911 // in case of multiple bounds ...
2912 if (bs.length() > 1) {
2913 // ... the variable's bound is a class type flagged COMPOUND
2914 // (see comment for TypeVar.bound).
2915 // In this case, generate a class tree that represents the
2916 // bound class, ...
2917 JCExpression extending;
2918 List<JCExpression> implementing;
2919 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
2920 extending = tree.bounds.head;
2921 implementing = tree.bounds.tail;
2922 } else {
2923 extending = null;
2924 implementing = tree.bounds;
2925 }
2926 JCClassDecl cd = make.at(tree.pos).ClassDef(
2927 make.Modifiers(PUBLIC | ABSTRACT),
2928 tree.name, List.<JCTypeParameter>nil(),
2929 extending, implementing, List.<JCTree>nil());
2931 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
2932 Assert.check((c.flags() & COMPOUND) != 0);
2933 cd.sym = c;
2934 c.sourcefile = env.toplevel.sourcefile;
2936 // ... and attribute the bound class
2937 c.flags_field |= UNATTRIBUTED;
2938 Env<AttrContext> cenv = enter.classEnv(cd, env);
2939 enter.typeEnvs.put(c, cenv);
2940 }
2941 }
2944 public void visitWildcard(JCWildcard tree) {
2945 //- System.err.println("visitWildcard("+tree+");");//DEBUG
2946 Type type = (tree.kind.kind == BoundKind.UNBOUND)
2947 ? syms.objectType
2948 : attribType(tree.inner, env);
2949 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
2950 tree.kind.kind,
2951 syms.boundClass),
2952 TYP, resultInfo);
2953 }
2955 public void visitAnnotation(JCAnnotation tree) {
2956 log.error(tree.pos(), "annotation.not.valid.for.type", pt());
2957 result = tree.type = syms.errType;
2958 }
2960 public void visitErroneous(JCErroneous tree) {
2961 if (tree.errs != null)
2962 for (JCTree err : tree.errs)
2963 attribTree(err, env, new ResultInfo(ERR, pt()));
2964 result = tree.type = syms.errType;
2965 }
2967 /** Default visitor method for all other trees.
2968 */
2969 public void visitTree(JCTree tree) {
2970 throw new AssertionError();
2971 }
2973 /**
2974 * Attribute an env for either a top level tree or class declaration.
2975 */
2976 public void attrib(Env<AttrContext> env) {
2977 if (env.tree.hasTag(TOPLEVEL))
2978 attribTopLevel(env);
2979 else
2980 attribClass(env.tree.pos(), env.enclClass.sym);
2981 }
2983 /**
2984 * Attribute a top level tree. These trees are encountered when the
2985 * package declaration has annotations.
2986 */
2987 public void attribTopLevel(Env<AttrContext> env) {
2988 JCCompilationUnit toplevel = env.toplevel;
2989 try {
2990 annotate.flush();
2991 chk.validateAnnotations(toplevel.packageAnnotations, toplevel.packge);
2992 } catch (CompletionFailure ex) {
2993 chk.completionError(toplevel.pos(), ex);
2994 }
2995 }
2997 /** Main method: attribute class definition associated with given class symbol.
2998 * reporting completion failures at the given position.
2999 * @param pos The source position at which completion errors are to be
3000 * reported.
3001 * @param c The class symbol whose definition will be attributed.
3002 */
3003 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
3004 try {
3005 annotate.flush();
3006 attribClass(c);
3007 } catch (CompletionFailure ex) {
3008 chk.completionError(pos, ex);
3009 }
3010 }
3012 /** Attribute class definition associated with given class symbol.
3013 * @param c The class symbol whose definition will be attributed.
3014 */
3015 void attribClass(ClassSymbol c) throws CompletionFailure {
3016 if (c.type.tag == ERROR) return;
3018 // Check for cycles in the inheritance graph, which can arise from
3019 // ill-formed class files.
3020 chk.checkNonCyclic(null, c.type);
3022 Type st = types.supertype(c.type);
3023 if ((c.flags_field & Flags.COMPOUND) == 0) {
3024 // First, attribute superclass.
3025 if (st.tag == CLASS)
3026 attribClass((ClassSymbol)st.tsym);
3028 // Next attribute owner, if it is a class.
3029 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
3030 attribClass((ClassSymbol)c.owner);
3031 }
3033 // The previous operations might have attributed the current class
3034 // if there was a cycle. So we test first whether the class is still
3035 // UNATTRIBUTED.
3036 if ((c.flags_field & UNATTRIBUTED) != 0) {
3037 c.flags_field &= ~UNATTRIBUTED;
3039 // Get environment current at the point of class definition.
3040 Env<AttrContext> env = enter.typeEnvs.get(c);
3042 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
3043 // because the annotations were not available at the time the env was created. Therefore,
3044 // we look up the environment chain for the first enclosing environment for which the
3045 // lint value is set. Typically, this is the parent env, but might be further if there
3046 // are any envs created as a result of TypeParameter nodes.
3047 Env<AttrContext> lintEnv = env;
3048 while (lintEnv.info.lint == null)
3049 lintEnv = lintEnv.next;
3051 // Having found the enclosing lint value, we can initialize the lint value for this class
3052 env.info.lint = lintEnv.info.lint.augment(c.annotations, c.flags());
3054 Lint prevLint = chk.setLint(env.info.lint);
3055 JavaFileObject prev = log.useSource(c.sourcefile);
3057 try {
3058 // java.lang.Enum may not be subclassed by a non-enum
3059 if (st.tsym == syms.enumSym &&
3060 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
3061 log.error(env.tree.pos(), "enum.no.subclassing");
3063 // Enums may not be extended by source-level classes
3064 if (st.tsym != null &&
3065 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
3066 ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
3067 !target.compilerBootstrap(c)) {
3068 log.error(env.tree.pos(), "enum.types.not.extensible");
3069 }
3070 attribClassBody(env, c);
3072 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
3073 } finally {
3074 log.useSource(prev);
3075 chk.setLint(prevLint);
3076 }
3078 }
3079 }
3081 public void visitImport(JCImport tree) {
3082 // nothing to do
3083 }
3085 /** Finish the attribution of a class. */
3086 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
3087 JCClassDecl tree = (JCClassDecl)env.tree;
3088 Assert.check(c == tree.sym);
3090 // Validate annotations
3091 chk.validateAnnotations(tree.mods.annotations, c);
3093 // Validate type parameters, supertype and interfaces.
3094 attribBounds(tree.typarams);
3095 if (!c.isAnonymous()) {
3096 //already checked if anonymous
3097 chk.validate(tree.typarams, env);
3098 chk.validate(tree.extending, env);
3099 chk.validate(tree.implementing, env);
3100 }
3102 // If this is a non-abstract class, check that it has no abstract
3103 // methods or unimplemented methods of an implemented interface.
3104 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
3105 if (!relax)
3106 chk.checkAllDefined(tree.pos(), c);
3107 }
3109 if ((c.flags() & ANNOTATION) != 0) {
3110 if (tree.implementing.nonEmpty())
3111 log.error(tree.implementing.head.pos(),
3112 "cant.extend.intf.annotation");
3113 if (tree.typarams.nonEmpty())
3114 log.error(tree.typarams.head.pos(),
3115 "intf.annotation.cant.have.type.params");
3117 // If this annotation has a @ContainedBy, validate
3118 Attribute.Compound containedBy = c.attribute(syms.containedByType.tsym);
3119 if (containedBy != null) {
3120 // get diagnositc position for error reporting
3121 DiagnosticPosition cbPos = getDiagnosticPosition(tree, containedBy.type);
3122 Assert.checkNonNull(cbPos);
3124 chk.validateContainedBy(c, containedBy, cbPos);
3125 }
3127 // If this annotation has a @ContainerFor, validate
3128 Attribute.Compound containerFor = c.attribute(syms.containerForType.tsym);
3129 if (containerFor != null) {
3130 // get diagnositc position for error reporting
3131 DiagnosticPosition cfPos = getDiagnosticPosition(tree, containerFor.type);
3132 Assert.checkNonNull(cfPos);
3134 chk.validateContainerFor(c, containerFor, cfPos);
3135 }
3136 } else {
3137 // Check that all extended classes and interfaces
3138 // are compatible (i.e. no two define methods with same arguments
3139 // yet different return types). (JLS 8.4.6.3)
3140 chk.checkCompatibleSupertypes(tree.pos(), c.type);
3141 }
3143 // Check that class does not import the same parameterized interface
3144 // with two different argument lists.
3145 chk.checkClassBounds(tree.pos(), c.type);
3147 tree.type = c.type;
3149 for (List<JCTypeParameter> l = tree.typarams;
3150 l.nonEmpty(); l = l.tail) {
3151 Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope);
3152 }
3154 // Check that a generic class doesn't extend Throwable
3155 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
3156 log.error(tree.extending.pos(), "generic.throwable");
3158 // Check that all methods which implement some
3159 // method conform to the method they implement.
3160 chk.checkImplementations(tree);
3162 //check that a resource implementing AutoCloseable cannot throw InterruptedException
3163 checkAutoCloseable(tree.pos(), env, c.type);
3165 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3166 // Attribute declaration
3167 attribStat(l.head, env);
3168 // Check that declarations in inner classes are not static (JLS 8.1.2)
3169 // Make an exception for static constants.
3170 if (c.owner.kind != PCK &&
3171 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
3172 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
3173 Symbol sym = null;
3174 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
3175 if (sym == null ||
3176 sym.kind != VAR ||
3177 ((VarSymbol) sym).getConstValue() == null)
3178 log.error(l.head.pos(), "icls.cant.have.static.decl", c);
3179 }
3180 }
3182 // Check for cycles among non-initial constructors.
3183 chk.checkCyclicConstructors(tree);
3185 // Check for cycles among annotation elements.
3186 chk.checkNonCyclicElements(tree);
3188 // Check for proper use of serialVersionUID
3189 if (env.info.lint.isEnabled(LintCategory.SERIAL) &&
3190 isSerializable(c) &&
3191 (c.flags() & Flags.ENUM) == 0 &&
3192 (c.flags() & ABSTRACT) == 0) {
3193 checkSerialVersionUID(tree, c);
3194 }
3195 }
3196 // where
3197 /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
3198 private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
3199 for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
3200 if (types.isSameType(al.head.annotationType.type, t))
3201 return al.head.pos();
3202 }
3204 return null;
3205 }
3207 /** check if a class is a subtype of Serializable, if that is available. */
3208 private boolean isSerializable(ClassSymbol c) {
3209 try {
3210 syms.serializableType.complete();
3211 }
3212 catch (CompletionFailure e) {
3213 return false;
3214 }
3215 return types.isSubtype(c.type, syms.serializableType);
3216 }
3218 /** Check that an appropriate serialVersionUID member is defined. */
3219 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
3221 // check for presence of serialVersionUID
3222 Scope.Entry e = c.members().lookup(names.serialVersionUID);
3223 while (e.scope != null && e.sym.kind != VAR) e = e.next();
3224 if (e.scope == null) {
3225 log.warning(LintCategory.SERIAL,
3226 tree.pos(), "missing.SVUID", c);
3227 return;
3228 }
3230 // check that it is static final
3231 VarSymbol svuid = (VarSymbol)e.sym;
3232 if ((svuid.flags() & (STATIC | FINAL)) !=
3233 (STATIC | FINAL))
3234 log.warning(LintCategory.SERIAL,
3235 TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
3237 // check that it is long
3238 else if (svuid.type.tag != TypeTags.LONG)
3239 log.warning(LintCategory.SERIAL,
3240 TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
3242 // check constant
3243 else if (svuid.getConstValue() == null)
3244 log.warning(LintCategory.SERIAL,
3245 TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
3246 }
3248 private Type capture(Type type) {
3249 return types.capture(type);
3250 }
3252 // <editor-fold desc="post-attribution visitor">
3254 /**
3255 * Handle missing types/symbols in an AST. This routine is useful when
3256 * the compiler has encountered some errors (which might have ended up
3257 * terminating attribution abruptly); if the compiler is used in fail-over
3258 * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
3259 * prevents NPE to be progagated during subsequent compilation steps.
3260 */
3261 public void postAttr(Env<AttrContext> env) {
3262 new PostAttrAnalyzer().scan(env.tree);
3263 }
3265 class PostAttrAnalyzer extends TreeScanner {
3267 private void initTypeIfNeeded(JCTree that) {
3268 if (that.type == null) {
3269 that.type = syms.unknownType;
3270 }
3271 }
3273 @Override
3274 public void scan(JCTree tree) {
3275 if (tree == null) return;
3276 if (tree instanceof JCExpression) {
3277 initTypeIfNeeded(tree);
3278 }
3279 super.scan(tree);
3280 }
3282 @Override
3283 public void visitIdent(JCIdent that) {
3284 if (that.sym == null) {
3285 that.sym = syms.unknownSymbol;
3286 }
3287 }
3289 @Override
3290 public void visitSelect(JCFieldAccess that) {
3291 if (that.sym == null) {
3292 that.sym = syms.unknownSymbol;
3293 }
3294 super.visitSelect(that);
3295 }
3297 @Override
3298 public void visitClassDef(JCClassDecl that) {
3299 initTypeIfNeeded(that);
3300 if (that.sym == null) {
3301 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
3302 }
3303 super.visitClassDef(that);
3304 }
3306 @Override
3307 public void visitMethodDef(JCMethodDecl that) {
3308 initTypeIfNeeded(that);
3309 if (that.sym == null) {
3310 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
3311 }
3312 super.visitMethodDef(that);
3313 }
3315 @Override
3316 public void visitVarDef(JCVariableDecl that) {
3317 initTypeIfNeeded(that);
3318 if (that.sym == null) {
3319 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
3320 that.sym.adr = 0;
3321 }
3322 super.visitVarDef(that);
3323 }
3325 @Override
3326 public void visitNewClass(JCNewClass that) {
3327 if (that.constructor == null) {
3328 that.constructor = new MethodSymbol(0, names.init, syms.unknownType, syms.noSymbol);
3329 }
3330 if (that.constructorType == null) {
3331 that.constructorType = syms.unknownType;
3332 }
3333 super.visitNewClass(that);
3334 }
3336 @Override
3337 public void visitAssignop(JCAssignOp that) {
3338 if (that.operator == null)
3339 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3340 super.visitAssignop(that);
3341 }
3343 @Override
3344 public void visitBinary(JCBinary that) {
3345 if (that.operator == null)
3346 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3347 super.visitBinary(that);
3348 }
3350 @Override
3351 public void visitUnary(JCUnary that) {
3352 if (that.operator == null)
3353 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
3354 super.visitUnary(that);
3355 }
3356 }
3357 // </editor-fold>
3358 }