Mercurial > jdk8-mips64-public > langtools / file revision
src/share/classes/com/sun/tools/javac/comp/Attr.java@36df13bde238
src/share/classes/com/sun/tools/javac/comp/Attr.java
Thu, 24 Jul 2008 11:12:41 +0100
- author
- mcimadamore
- date
- Thu, 24 Jul 2008 11:12:41 +0100
- changeset 79
- 36df13bde238
- parent 54
- eaf608c64fec
- child 80
- 5c9cdeb740f2
- permissions
- -rw-r--r--
6594284: NPE thrown when calling a method on an intersection type
Summary: javac should report an error when the capture of an actual type parameter does not exist
Reviewed-by: jjg
1 /*
2 * Copyright 1999-2008 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
26 package com.sun.tools.javac.comp;
28 import java.util.*;
29 import java.util.Set;
30 import javax.lang.model.element.ElementKind;
31 import javax.tools.JavaFileObject;
33 import com.sun.tools.javac.code.*;
34 import com.sun.tools.javac.jvm.*;
35 import com.sun.tools.javac.tree.*;
36 import com.sun.tools.javac.util.*;
37 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
38 import com.sun.tools.javac.util.List;
40 import com.sun.tools.javac.jvm.Target;
41 import com.sun.tools.javac.code.Symbol.*;
42 import com.sun.tools.javac.tree.JCTree.*;
43 import com.sun.tools.javac.code.Type.*;
45 import com.sun.source.tree.IdentifierTree;
46 import com.sun.source.tree.MemberSelectTree;
47 import com.sun.source.tree.TreeVisitor;
48 import com.sun.source.util.SimpleTreeVisitor;
50 import static com.sun.tools.javac.code.Flags.*;
51 import static com.sun.tools.javac.code.Kinds.*;
52 import static com.sun.tools.javac.code.TypeTags.*;
54 /** This is the main context-dependent analysis phase in GJC. It
55 * encompasses name resolution, type checking and constant folding as
56 * subtasks. Some subtasks involve auxiliary classes.
57 * @see Check
58 * @see Resolve
59 * @see ConstFold
60 * @see Infer
61 *
62 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
63 * you write code that depends on this, you do so at your own risk.
64 * This code and its internal interfaces are subject to change or
65 * deletion without notice.</b>
66 */
67 public class Attr extends JCTree.Visitor {
68 protected static final Context.Key<Attr> attrKey =
69 new Context.Key<Attr>();
71 final Name.Table names;
72 final Log log;
73 final Symtab syms;
74 final Resolve rs;
75 final Check chk;
76 final MemberEnter memberEnter;
77 final TreeMaker make;
78 final ConstFold cfolder;
79 final Enter enter;
80 final Target target;
81 final Types types;
82 final Annotate annotate;
84 public static Attr instance(Context context) {
85 Attr instance = context.get(attrKey);
86 if (instance == null)
87 instance = new Attr(context);
88 return instance;
89 }
91 protected Attr(Context context) {
92 context.put(attrKey, this);
94 names = Name.Table.instance(context);
95 log = Log.instance(context);
96 syms = Symtab.instance(context);
97 rs = Resolve.instance(context);
98 chk = Check.instance(context);
99 memberEnter = MemberEnter.instance(context);
100 make = TreeMaker.instance(context);
101 enter = Enter.instance(context);
102 cfolder = ConstFold.instance(context);
103 target = Target.instance(context);
104 types = Types.instance(context);
105 annotate = Annotate.instance(context);
107 Options options = Options.instance(context);
109 Source source = Source.instance(context);
110 allowGenerics = source.allowGenerics();
111 allowVarargs = source.allowVarargs();
112 allowEnums = source.allowEnums();
113 allowBoxing = source.allowBoxing();
114 allowCovariantReturns = source.allowCovariantReturns();
115 allowAnonOuterThis = source.allowAnonOuterThis();
116 relax = (options.get("-retrofit") != null ||
117 options.get("-relax") != null);
118 useBeforeDeclarationWarning = options.get("useBeforeDeclarationWarning") != null;
119 }
121 /** Switch: relax some constraints for retrofit mode.
122 */
123 boolean relax;
125 /** Switch: support generics?
126 */
127 boolean allowGenerics;
129 /** Switch: allow variable-arity methods.
130 */
131 boolean allowVarargs;
133 /** Switch: support enums?
134 */
135 boolean allowEnums;
137 /** Switch: support boxing and unboxing?
138 */
139 boolean allowBoxing;
141 /** Switch: support covariant result types?
142 */
143 boolean allowCovariantReturns;
145 /** Switch: allow references to surrounding object from anonymous
146 * objects during constructor call?
147 */
148 boolean allowAnonOuterThis;
150 /**
151 * Switch: warn about use of variable before declaration?
152 * RFE: 6425594
153 */
154 boolean useBeforeDeclarationWarning;
156 /** Check kind and type of given tree against protokind and prototype.
157 * If check succeeds, store type in tree and return it.
158 * If check fails, store errType in tree and return it.
159 * No checks are performed if the prototype is a method type.
160 * Its not necessary in this case since we know that kind and type
161 * are correct.
162 *
163 * @param tree The tree whose kind and type is checked
164 * @param owntype The computed type of the tree
165 * @param ownkind The computed kind of the tree
166 * @param pkind The expected kind (or: protokind) of the tree
167 * @param pt The expected type (or: prototype) of the tree
168 */
169 Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
170 if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
171 if ((ownkind & ~pkind) == 0) {
172 owntype = chk.checkType(tree.pos(), owntype, pt);
173 } else {
174 log.error(tree.pos(), "unexpected.type",
175 Resolve.kindNames(pkind),
176 Resolve.kindName(ownkind));
177 owntype = syms.errType;
178 }
179 }
180 tree.type = owntype;
181 return owntype;
182 }
184 /** Is given blank final variable assignable, i.e. in a scope where it
185 * may be assigned to even though it is final?
186 * @param v The blank final variable.
187 * @param env The current environment.
188 */
189 boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
190 Symbol owner = env.info.scope.owner;
191 // owner refers to the innermost variable, method or
192 // initializer block declaration at this point.
193 return
194 v.owner == owner
195 ||
196 ((owner.name == names.init || // i.e. we are in a constructor
197 owner.kind == VAR || // i.e. we are in a variable initializer
198 (owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
199 &&
200 v.owner == owner.owner
201 &&
202 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
203 }
205 /** Check that variable can be assigned to.
206 * @param pos The current source code position.
207 * @param v The assigned varaible
208 * @param base If the variable is referred to in a Select, the part
209 * to the left of the `.', null otherwise.
210 * @param env The current environment.
211 */
212 void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
213 if ((v.flags() & FINAL) != 0 &&
214 ((v.flags() & HASINIT) != 0
215 ||
216 !((base == null ||
217 (base.getTag() == JCTree.IDENT && TreeInfo.name(base) == names._this)) &&
218 isAssignableAsBlankFinal(v, env)))) {
219 log.error(pos, "cant.assign.val.to.final.var", v);
220 }
221 }
223 /** Does tree represent a static reference to an identifier?
224 * It is assumed that tree is either a SELECT or an IDENT.
225 * We have to weed out selects from non-type names here.
226 * @param tree The candidate tree.
227 */
228 boolean isStaticReference(JCTree tree) {
229 if (tree.getTag() == JCTree.SELECT) {
230 Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
231 if (lsym == null || lsym.kind != TYP) {
232 return false;
233 }
234 }
235 return true;
236 }
238 /** Is this symbol a type?
239 */
240 static boolean isType(Symbol sym) {
241 return sym != null && sym.kind == TYP;
242 }
244 /** The current `this' symbol.
245 * @param env The current environment.
246 */
247 Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
248 return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
249 }
251 /** Attribute a parsed identifier.
252 * @param tree Parsed identifier name
253 * @param topLevel The toplevel to use
254 */
255 public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
256 Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
257 localEnv.enclClass = make.ClassDef(make.Modifiers(0),
258 syms.errSymbol.name,
259 null, null, null, null);
260 localEnv.enclClass.sym = syms.errSymbol;
261 return tree.accept(identAttributer, localEnv);
262 }
263 // where
264 private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
265 private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
266 @Override
267 public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
268 Symbol site = visit(node.getExpression(), env);
269 if (site.kind == ERR)
270 return site;
271 Name name = (Name)node.getIdentifier();
272 if (site.kind == PCK) {
273 env.toplevel.packge = (PackageSymbol)site;
274 return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
275 } else {
276 env.enclClass.sym = (ClassSymbol)site;
277 return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
278 }
279 }
281 @Override
282 public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
283 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
284 }
285 }
287 public Type coerce(Type etype, Type ttype) {
288 return cfolder.coerce(etype, ttype);
289 }
291 public Type attribType(JCTree node, TypeSymbol sym) {
292 Env<AttrContext> env = enter.typeEnvs.get(sym);
293 Env<AttrContext> localEnv = env.dup(node, env.info.dup());
294 return attribTree(node, localEnv, Kinds.TYP, Type.noType);
295 }
297 public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
298 breakTree = tree;
299 JavaFileObject prev = log.useSource(null);
300 try {
301 attribExpr(expr, env);
302 } catch (BreakAttr b) {
303 return b.env;
304 } finally {
305 breakTree = null;
306 log.useSource(prev);
307 }
308 return env;
309 }
311 public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
312 breakTree = tree;
313 JavaFileObject prev = log.useSource(null);
314 try {
315 attribStat(stmt, env);
316 } catch (BreakAttr b) {
317 return b.env;
318 } finally {
319 breakTree = null;
320 log.useSource(prev);
321 }
322 return env;
323 }
325 private JCTree breakTree = null;
327 private static class BreakAttr extends RuntimeException {
328 static final long serialVersionUID = -6924771130405446405L;
329 private Env<AttrContext> env;
330 private BreakAttr(Env<AttrContext> env) {
331 this.env = env;
332 }
333 }
336 /* ************************************************************************
337 * Visitor methods
338 *************************************************************************/
340 /** Visitor argument: the current environment.
341 */
342 Env<AttrContext> env;
344 /** Visitor argument: the currently expected proto-kind.
345 */
346 int pkind;
348 /** Visitor argument: the currently expected proto-type.
349 */
350 Type pt;
352 /** Visitor result: the computed type.
353 */
354 Type result;
356 /** Visitor method: attribute a tree, catching any completion failure
357 * exceptions. Return the tree's type.
358 *
359 * @param tree The tree to be visited.
360 * @param env The environment visitor argument.
361 * @param pkind The protokind visitor argument.
362 * @param pt The prototype visitor argument.
363 */
364 Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) {
365 Env<AttrContext> prevEnv = this.env;
366 int prevPkind = this.pkind;
367 Type prevPt = this.pt;
368 try {
369 this.env = env;
370 this.pkind = pkind;
371 this.pt = pt;
372 tree.accept(this);
373 if (tree == breakTree)
374 throw new BreakAttr(env);
375 return result;
376 } catch (CompletionFailure ex) {
377 tree.type = syms.errType;
378 return chk.completionError(tree.pos(), ex);
379 } finally {
380 this.env = prevEnv;
381 this.pkind = prevPkind;
382 this.pt = prevPt;
383 }
384 }
386 /** Derived visitor method: attribute an expression tree.
387 */
388 public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
389 return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
390 }
392 /** Derived visitor method: attribute an expression tree with
393 * no constraints on the computed type.
394 */
395 Type attribExpr(JCTree tree, Env<AttrContext> env) {
396 return attribTree(tree, env, VAL, Type.noType);
397 }
399 /** Derived visitor method: attribute a type tree.
400 */
401 Type attribType(JCTree tree, Env<AttrContext> env) {
402 Type result = attribTree(tree, env, TYP, Type.noType);
403 return result;
404 }
406 /** Derived visitor method: attribute a statement or definition tree.
407 */
408 public Type attribStat(JCTree tree, Env<AttrContext> env) {
409 return attribTree(tree, env, NIL, Type.noType);
410 }
412 /** Attribute a list of expressions, returning a list of types.
413 */
414 List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
415 ListBuffer<Type> ts = new ListBuffer<Type>();
416 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
417 ts.append(attribExpr(l.head, env, pt));
418 return ts.toList();
419 }
421 /** Attribute a list of statements, returning nothing.
422 */
423 <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
424 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
425 attribStat(l.head, env);
426 }
428 /** Attribute the arguments in a method call, returning a list of types.
429 */
430 List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
431 ListBuffer<Type> argtypes = new ListBuffer<Type>();
432 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
433 argtypes.append(chk.checkNonVoid(
434 l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly))));
435 return argtypes.toList();
436 }
438 /** Attribute a type argument list, returning a list of types.
439 */
440 List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
441 ListBuffer<Type> argtypes = new ListBuffer<Type>();
442 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
443 argtypes.append(chk.checkRefType(l.head.pos(), attribType(l.head, env)));
444 return argtypes.toList();
445 }
448 /**
449 * Attribute type variables (of generic classes or methods).
450 * Compound types are attributed later in attribBounds.
451 * @param typarams the type variables to enter
452 * @param env the current environment
453 */
454 void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
455 for (JCTypeParameter tvar : typarams) {
456 TypeVar a = (TypeVar)tvar.type;
457 a.tsym.flags_field |= UNATTRIBUTED;
458 a.bound = Type.noType;
459 if (!tvar.bounds.isEmpty()) {
460 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
461 for (JCExpression bound : tvar.bounds.tail)
462 bounds = bounds.prepend(attribType(bound, env));
463 types.setBounds(a, bounds.reverse());
464 } else {
465 // if no bounds are given, assume a single bound of
466 // java.lang.Object.
467 types.setBounds(a, List.of(syms.objectType));
468 }
469 a.tsym.flags_field &= ~UNATTRIBUTED;
470 }
471 for (JCTypeParameter tvar : typarams)
472 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
473 attribStats(typarams, env);
474 }
476 void attribBounds(List<JCTypeParameter> typarams) {
477 for (JCTypeParameter typaram : typarams) {
478 Type bound = typaram.type.getUpperBound();
479 if (bound != null && bound.tsym instanceof ClassSymbol) {
480 ClassSymbol c = (ClassSymbol)bound.tsym;
481 if ((c.flags_field & COMPOUND) != 0) {
482 assert (c.flags_field & UNATTRIBUTED) != 0 : c;
483 attribClass(typaram.pos(), c);
484 }
485 }
486 }
487 }
489 /**
490 * Attribute the type references in a list of annotations.
491 */
492 void attribAnnotationTypes(List<JCAnnotation> annotations,
493 Env<AttrContext> env) {
494 for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
495 JCAnnotation a = al.head;
496 attribType(a.annotationType, env);
497 }
498 }
500 /** Attribute type reference in an `extends' or `implements' clause.
501 *
502 * @param tree The tree making up the type reference.
503 * @param env The environment current at the reference.
504 * @param classExpected true if only a class is expected here.
505 * @param interfaceExpected true if only an interface is expected here.
506 */
507 Type attribBase(JCTree tree,
508 Env<AttrContext> env,
509 boolean classExpected,
510 boolean interfaceExpected,
511 boolean checkExtensible) {
512 Type t = attribType(tree, env);
513 return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
514 }
515 Type checkBase(Type t,
516 JCTree tree,
517 Env<AttrContext> env,
518 boolean classExpected,
519 boolean interfaceExpected,
520 boolean checkExtensible) {
521 if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
522 // check that type variable is already visible
523 if (t.getUpperBound() == null) {
524 log.error(tree.pos(), "illegal.forward.ref");
525 return syms.errType;
526 }
527 } else {
528 t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
529 }
530 if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
531 log.error(tree.pos(), "intf.expected.here");
532 // return errType is necessary since otherwise there might
533 // be undetected cycles which cause attribution to loop
534 return syms.errType;
535 } else if (checkExtensible &&
536 classExpected &&
537 (t.tsym.flags() & INTERFACE) != 0) {
538 log.error(tree.pos(), "no.intf.expected.here");
539 return syms.errType;
540 }
541 if (checkExtensible &&
542 ((t.tsym.flags() & FINAL) != 0)) {
543 log.error(tree.pos(),
544 "cant.inherit.from.final", t.tsym);
545 }
546 chk.checkNonCyclic(tree.pos(), t);
547 return t;
548 }
550 public void visitClassDef(JCClassDecl tree) {
551 // Local classes have not been entered yet, so we need to do it now:
552 if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
553 enter.classEnter(tree, env);
555 ClassSymbol c = tree.sym;
556 if (c == null) {
557 // exit in case something drastic went wrong during enter.
558 result = null;
559 } else {
560 // make sure class has been completed:
561 c.complete();
563 // If this class appears as an anonymous class
564 // in a superclass constructor call where
565 // no explicit outer instance is given,
566 // disable implicit outer instance from being passed.
567 // (This would be an illegal access to "this before super").
568 if (env.info.isSelfCall &&
569 env.tree.getTag() == JCTree.NEWCLASS &&
570 ((JCNewClass) env.tree).encl == null)
571 {
572 c.flags_field |= NOOUTERTHIS;
573 }
574 attribClass(tree.pos(), c);
575 result = tree.type = c.type;
576 }
577 }
579 public void visitMethodDef(JCMethodDecl tree) {
580 MethodSymbol m = tree.sym;
582 Lint lint = env.info.lint.augment(m.attributes_field, m.flags());
583 Lint prevLint = chk.setLint(lint);
584 try {
585 chk.checkDeprecatedAnnotation(tree.pos(), m);
587 attribBounds(tree.typarams);
589 // If we override any other methods, check that we do so properly.
590 // JLS ???
591 chk.checkOverride(tree, m);
593 // Create a new environment with local scope
594 // for attributing the method.
595 Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
597 localEnv.info.lint = lint;
599 // Enter all type parameters into the local method scope.
600 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
601 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
603 ClassSymbol owner = env.enclClass.sym;
604 if ((owner.flags() & ANNOTATION) != 0 &&
605 tree.params.nonEmpty())
606 log.error(tree.params.head.pos(),
607 "intf.annotation.members.cant.have.params");
609 // Attribute all value parameters.
610 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
611 attribStat(l.head, localEnv);
612 }
614 // Check that type parameters are well-formed.
615 chk.validateTypeParams(tree.typarams);
616 if ((owner.flags() & ANNOTATION) != 0 &&
617 tree.typarams.nonEmpty())
618 log.error(tree.typarams.head.pos(),
619 "intf.annotation.members.cant.have.type.params");
621 // Check that result type is well-formed.
622 chk.validate(tree.restype);
623 if ((owner.flags() & ANNOTATION) != 0)
624 chk.validateAnnotationType(tree.restype);
626 if ((owner.flags() & ANNOTATION) != 0)
627 chk.validateAnnotationMethod(tree.pos(), m);
629 // Check that all exceptions mentioned in the throws clause extend
630 // java.lang.Throwable.
631 if ((owner.flags() & ANNOTATION) != 0 && tree.thrown.nonEmpty())
632 log.error(tree.thrown.head.pos(),
633 "throws.not.allowed.in.intf.annotation");
634 for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
635 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
637 if (tree.body == null) {
638 // Empty bodies are only allowed for
639 // abstract, native, or interface methods, or for methods
640 // in a retrofit signature class.
641 if ((owner.flags() & INTERFACE) == 0 &&
642 (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 &&
643 !relax)
644 log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
645 if (tree.defaultValue != null) {
646 if ((owner.flags() & ANNOTATION) == 0)
647 log.error(tree.pos(),
648 "default.allowed.in.intf.annotation.member");
649 }
650 } else if ((owner.flags() & INTERFACE) != 0) {
651 log.error(tree.body.pos(), "intf.meth.cant.have.body");
652 } else if ((tree.mods.flags & ABSTRACT) != 0) {
653 log.error(tree.pos(), "abstract.meth.cant.have.body");
654 } else if ((tree.mods.flags & NATIVE) != 0) {
655 log.error(tree.pos(), "native.meth.cant.have.body");
656 } else {
657 // Add an implicit super() call unless an explicit call to
658 // super(...) or this(...) is given
659 // or we are compiling class java.lang.Object.
660 if (tree.name == names.init && owner.type != syms.objectType) {
661 JCBlock body = tree.body;
662 if (body.stats.isEmpty() ||
663 !TreeInfo.isSelfCall(body.stats.head)) {
664 body.stats = body.stats.
665 prepend(memberEnter.SuperCall(make.at(body.pos),
666 List.<Type>nil(),
667 List.<JCVariableDecl>nil(),
668 false));
669 } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
670 (tree.mods.flags & GENERATEDCONSTR) == 0 &&
671 TreeInfo.isSuperCall(body.stats.head)) {
672 // enum constructors are not allowed to call super
673 // directly, so make sure there aren't any super calls
674 // in enum constructors, except in the compiler
675 // generated one.
676 log.error(tree.body.stats.head.pos(),
677 "call.to.super.not.allowed.in.enum.ctor",
678 env.enclClass.sym);
679 }
680 }
682 // Attribute method body.
683 attribStat(tree.body, localEnv);
684 }
685 localEnv.info.scope.leave();
686 result = tree.type = m.type;
687 chk.validateAnnotations(tree.mods.annotations, m);
689 }
690 finally {
691 chk.setLint(prevLint);
692 }
693 }
695 public void visitVarDef(JCVariableDecl tree) {
696 // Local variables have not been entered yet, so we need to do it now:
697 if (env.info.scope.owner.kind == MTH) {
698 if (tree.sym != null) {
699 // parameters have already been entered
700 env.info.scope.enter(tree.sym);
701 } else {
702 memberEnter.memberEnter(tree, env);
703 annotate.flush();
704 }
705 }
707 // Check that the variable's declared type is well-formed.
708 chk.validate(tree.vartype);
710 VarSymbol v = tree.sym;
711 Lint lint = env.info.lint.augment(v.attributes_field, v.flags());
712 Lint prevLint = chk.setLint(lint);
714 try {
715 chk.checkDeprecatedAnnotation(tree.pos(), v);
717 if (tree.init != null) {
718 if ((v.flags_field & FINAL) != 0 && tree.init.getTag() != JCTree.NEWCLASS) {
719 // In this case, `v' is final. Ensure that it's initializer is
720 // evaluated.
721 v.getConstValue(); // ensure initializer is evaluated
722 } else {
723 // Attribute initializer in a new environment
724 // with the declared variable as owner.
725 // Check that initializer conforms to variable's declared type.
726 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
727 initEnv.info.lint = lint;
728 // In order to catch self-references, we set the variable's
729 // declaration position to maximal possible value, effectively
730 // marking the variable as undefined.
731 v.pos = Position.MAXPOS;
732 attribExpr(tree.init, initEnv, v.type);
733 v.pos = tree.pos;
734 }
735 }
736 result = tree.type = v.type;
737 chk.validateAnnotations(tree.mods.annotations, v);
738 }
739 finally {
740 chk.setLint(prevLint);
741 }
742 }
744 public void visitSkip(JCSkip tree) {
745 result = null;
746 }
748 public void visitBlock(JCBlock tree) {
749 if (env.info.scope.owner.kind == TYP) {
750 // Block is a static or instance initializer;
751 // let the owner of the environment be a freshly
752 // created BLOCK-method.
753 Env<AttrContext> localEnv =
754 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
755 localEnv.info.scope.owner =
756 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
757 env.info.scope.owner);
758 if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
759 attribStats(tree.stats, localEnv);
760 } else {
761 // Create a new local environment with a local scope.
762 Env<AttrContext> localEnv =
763 env.dup(tree, env.info.dup(env.info.scope.dup()));
764 attribStats(tree.stats, localEnv);
765 localEnv.info.scope.leave();
766 }
767 result = null;
768 }
770 public void visitDoLoop(JCDoWhileLoop tree) {
771 attribStat(tree.body, env.dup(tree));
772 attribExpr(tree.cond, env, syms.booleanType);
773 result = null;
774 }
776 public void visitWhileLoop(JCWhileLoop tree) {
777 attribExpr(tree.cond, env, syms.booleanType);
778 attribStat(tree.body, env.dup(tree));
779 result = null;
780 }
782 public void visitForLoop(JCForLoop tree) {
783 Env<AttrContext> loopEnv =
784 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
785 attribStats(tree.init, loopEnv);
786 if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
787 loopEnv.tree = tree; // before, we were not in loop!
788 attribStats(tree.step, loopEnv);
789 attribStat(tree.body, loopEnv);
790 loopEnv.info.scope.leave();
791 result = null;
792 }
794 public void visitForeachLoop(JCEnhancedForLoop tree) {
795 Env<AttrContext> loopEnv =
796 env.dup(env.tree, env.info.dup(env.info.scope.dup()));
797 attribStat(tree.var, loopEnv);
798 Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
799 chk.checkNonVoid(tree.pos(), exprType);
800 Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
801 if (elemtype == null) {
802 // or perhaps expr implements Iterable<T>?
803 Type base = types.asSuper(exprType, syms.iterableType.tsym);
804 if (base == null) {
805 log.error(tree.expr.pos(), "foreach.not.applicable.to.type");
806 elemtype = syms.errType;
807 } else {
808 List<Type> iterableParams = base.allparams();
809 elemtype = iterableParams.isEmpty()
810 ? syms.objectType
811 : types.upperBound(iterableParams.head);
812 }
813 }
814 chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
815 loopEnv.tree = tree; // before, we were not in loop!
816 attribStat(tree.body, loopEnv);
817 loopEnv.info.scope.leave();
818 result = null;
819 }
821 public void visitLabelled(JCLabeledStatement tree) {
822 // Check that label is not used in an enclosing statement
823 Env<AttrContext> env1 = env;
824 while (env1 != null && env1.tree.getTag() != JCTree.CLASSDEF) {
825 if (env1.tree.getTag() == JCTree.LABELLED &&
826 ((JCLabeledStatement) env1.tree).label == tree.label) {
827 log.error(tree.pos(), "label.already.in.use",
828 tree.label);
829 break;
830 }
831 env1 = env1.next;
832 }
834 attribStat(tree.body, env.dup(tree));
835 result = null;
836 }
838 public void visitSwitch(JCSwitch tree) {
839 Type seltype = attribExpr(tree.selector, env);
841 Env<AttrContext> switchEnv =
842 env.dup(tree, env.info.dup(env.info.scope.dup()));
844 boolean enumSwitch =
845 allowEnums &&
846 (seltype.tsym.flags() & Flags.ENUM) != 0;
847 if (!enumSwitch)
848 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
850 // Attribute all cases and
851 // check that there are no duplicate case labels or default clauses.
852 Set<Object> labels = new HashSet<Object>(); // The set of case labels.
853 boolean hasDefault = false; // Is there a default label?
854 for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
855 JCCase c = l.head;
856 Env<AttrContext> caseEnv =
857 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
858 if (c.pat != null) {
859 if (enumSwitch) {
860 Symbol sym = enumConstant(c.pat, seltype);
861 if (sym == null) {
862 log.error(c.pat.pos(), "enum.const.req");
863 } else if (!labels.add(sym)) {
864 log.error(c.pos(), "duplicate.case.label");
865 }
866 } else {
867 Type pattype = attribExpr(c.pat, switchEnv, seltype);
868 if (pattype.tag != ERROR) {
869 if (pattype.constValue() == null) {
870 log.error(c.pat.pos(), "const.expr.req");
871 } else if (labels.contains(pattype.constValue())) {
872 log.error(c.pos(), "duplicate.case.label");
873 } else {
874 labels.add(pattype.constValue());
875 }
876 }
877 }
878 } else if (hasDefault) {
879 log.error(c.pos(), "duplicate.default.label");
880 } else {
881 hasDefault = true;
882 }
883 attribStats(c.stats, caseEnv);
884 caseEnv.info.scope.leave();
885 addVars(c.stats, switchEnv.info.scope);
886 }
888 switchEnv.info.scope.leave();
889 result = null;
890 }
891 // where
892 /** Add any variables defined in stats to the switch scope. */
893 private static void addVars(List<JCStatement> stats, Scope switchScope) {
894 for (;stats.nonEmpty(); stats = stats.tail) {
895 JCTree stat = stats.head;
896 if (stat.getTag() == JCTree.VARDEF)
897 switchScope.enter(((JCVariableDecl) stat).sym);
898 }
899 }
900 // where
901 /** Return the selected enumeration constant symbol, or null. */
902 private Symbol enumConstant(JCTree tree, Type enumType) {
903 if (tree.getTag() != JCTree.IDENT) {
904 log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
905 return syms.errSymbol;
906 }
907 JCIdent ident = (JCIdent)tree;
908 Name name = ident.name;
909 for (Scope.Entry e = enumType.tsym.members().lookup(name);
910 e.scope != null; e = e.next()) {
911 if (e.sym.kind == VAR) {
912 Symbol s = ident.sym = e.sym;
913 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
914 ident.type = s.type;
915 return ((s.flags_field & Flags.ENUM) == 0)
916 ? null : s;
917 }
918 }
919 return null;
920 }
922 public void visitSynchronized(JCSynchronized tree) {
923 chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
924 attribStat(tree.body, env);
925 result = null;
926 }
928 public void visitTry(JCTry tree) {
929 // Attribute body
930 attribStat(tree.body, env.dup(tree, env.info.dup()));
932 // Attribute catch clauses
933 for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
934 JCCatch c = l.head;
935 Env<AttrContext> catchEnv =
936 env.dup(c, env.info.dup(env.info.scope.dup()));
937 Type ctype = attribStat(c.param, catchEnv);
938 if (c.param.type.tsym.kind == Kinds.VAR) {
939 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
940 }
941 chk.checkType(c.param.vartype.pos(),
942 chk.checkClassType(c.param.vartype.pos(), ctype),
943 syms.throwableType);
944 attribStat(c.body, catchEnv);
945 catchEnv.info.scope.leave();
946 }
948 // Attribute finalizer
949 if (tree.finalizer != null) attribStat(tree.finalizer, env);
950 result = null;
951 }
953 public void visitConditional(JCConditional tree) {
954 attribExpr(tree.cond, env, syms.booleanType);
955 attribExpr(tree.truepart, env);
956 attribExpr(tree.falsepart, env);
957 result = check(tree,
958 capture(condType(tree.pos(), tree.cond.type,
959 tree.truepart.type, tree.falsepart.type)),
960 VAL, pkind, pt);
961 }
962 //where
963 /** Compute the type of a conditional expression, after
964 * checking that it exists. See Spec 15.25.
965 *
966 * @param pos The source position to be used for
967 * error diagnostics.
968 * @param condtype The type of the expression's condition.
969 * @param thentype The type of the expression's then-part.
970 * @param elsetype The type of the expression's else-part.
971 */
972 private Type condType(DiagnosticPosition pos,
973 Type condtype,
974 Type thentype,
975 Type elsetype) {
976 Type ctype = condType1(pos, condtype, thentype, elsetype);
978 // If condition and both arms are numeric constants,
979 // evaluate at compile-time.
980 return ((condtype.constValue() != null) &&
981 (thentype.constValue() != null) &&
982 (elsetype.constValue() != null))
983 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
984 : ctype;
985 }
986 /** Compute the type of a conditional expression, after
987 * checking that it exists. Does not take into
988 * account the special case where condition and both arms
989 * are constants.
990 *
991 * @param pos The source position to be used for error
992 * diagnostics.
993 * @param condtype The type of the expression's condition.
994 * @param thentype The type of the expression's then-part.
995 * @param elsetype The type of the expression's else-part.
996 */
997 private Type condType1(DiagnosticPosition pos, Type condtype,
998 Type thentype, Type elsetype) {
999 // If same type, that is the result
1000 if (types.isSameType(thentype, elsetype))
1001 return thentype.baseType();
1003 Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1004 ? thentype : types.unboxedType(thentype);
1005 Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1006 ? elsetype : types.unboxedType(elsetype);
1008 // Otherwise, if both arms can be converted to a numeric
1009 // type, return the least numeric type that fits both arms
1010 // (i.e. return larger of the two, or return int if one
1011 // arm is short, the other is char).
1012 if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1013 // If one arm has an integer subrange type (i.e., byte,
1014 // short, or char), and the other is an integer constant
1015 // that fits into the subrange, return the subrange type.
1016 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1017 types.isAssignable(elseUnboxed, thenUnboxed))
1018 return thenUnboxed.baseType();
1019 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1020 types.isAssignable(thenUnboxed, elseUnboxed))
1021 return elseUnboxed.baseType();
1023 for (int i = BYTE; i < VOID; i++) {
1024 Type candidate = syms.typeOfTag[i];
1025 if (types.isSubtype(thenUnboxed, candidate) &&
1026 types.isSubtype(elseUnboxed, candidate))
1027 return candidate;
1028 }
1029 }
1031 // Those were all the cases that could result in a primitive
1032 if (allowBoxing) {
1033 if (thentype.isPrimitive())
1034 thentype = types.boxedClass(thentype).type;
1035 if (elsetype.isPrimitive())
1036 elsetype = types.boxedClass(elsetype).type;
1037 }
1039 if (types.isSubtype(thentype, elsetype))
1040 return elsetype.baseType();
1041 if (types.isSubtype(elsetype, thentype))
1042 return thentype.baseType();
1044 if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1045 log.error(pos, "neither.conditional.subtype",
1046 thentype, elsetype);
1047 return thentype.baseType();
1048 }
1050 // both are known to be reference types. The result is
1051 // lub(thentype,elsetype). This cannot fail, as it will
1052 // always be possible to infer "Object" if nothing better.
1053 return types.lub(thentype.baseType(), elsetype.baseType());
1054 }
1056 public void visitIf(JCIf tree) {
1057 attribExpr(tree.cond, env, syms.booleanType);
1058 attribStat(tree.thenpart, env);
1059 if (tree.elsepart != null)
1060 attribStat(tree.elsepart, env);
1061 chk.checkEmptyIf(tree);
1062 result = null;
1063 }
1065 public void visitExec(JCExpressionStatement tree) {
1066 attribExpr(tree.expr, env);
1067 result = null;
1068 }
1070 public void visitBreak(JCBreak tree) {
1071 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1072 result = null;
1073 }
1075 public void visitContinue(JCContinue tree) {
1076 tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1077 result = null;
1078 }
1079 //where
1080 /** Return the target of a break or continue statement, if it exists,
1081 * report an error if not.
1082 * Note: The target of a labelled break or continue is the
1083 * (non-labelled) statement tree referred to by the label,
1084 * not the tree representing the labelled statement itself.
1085 *
1086 * @param pos The position to be used for error diagnostics
1087 * @param tag The tag of the jump statement. This is either
1088 * Tree.BREAK or Tree.CONTINUE.
1089 * @param label The label of the jump statement, or null if no
1090 * label is given.
1091 * @param env The environment current at the jump statement.
1092 */
1093 private JCTree findJumpTarget(DiagnosticPosition pos,
1094 int tag,
1095 Name label,
1096 Env<AttrContext> env) {
1097 // Search environments outwards from the point of jump.
1098 Env<AttrContext> env1 = env;
1099 LOOP:
1100 while (env1 != null) {
1101 switch (env1.tree.getTag()) {
1102 case JCTree.LABELLED:
1103 JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1104 if (label == labelled.label) {
1105 // If jump is a continue, check that target is a loop.
1106 if (tag == JCTree.CONTINUE) {
1107 if (labelled.body.getTag() != JCTree.DOLOOP &&
1108 labelled.body.getTag() != JCTree.WHILELOOP &&
1109 labelled.body.getTag() != JCTree.FORLOOP &&
1110 labelled.body.getTag() != JCTree.FOREACHLOOP)
1111 log.error(pos, "not.loop.label", label);
1112 // Found labelled statement target, now go inwards
1113 // to next non-labelled tree.
1114 return TreeInfo.referencedStatement(labelled);
1115 } else {
1116 return labelled;
1117 }
1118 }
1119 break;
1120 case JCTree.DOLOOP:
1121 case JCTree.WHILELOOP:
1122 case JCTree.FORLOOP:
1123 case JCTree.FOREACHLOOP:
1124 if (label == null) return env1.tree;
1125 break;
1126 case JCTree.SWITCH:
1127 if (label == null && tag == JCTree.BREAK) return env1.tree;
1128 break;
1129 case JCTree.METHODDEF:
1130 case JCTree.CLASSDEF:
1131 break LOOP;
1132 default:
1133 }
1134 env1 = env1.next;
1135 }
1136 if (label != null)
1137 log.error(pos, "undef.label", label);
1138 else if (tag == JCTree.CONTINUE)
1139 log.error(pos, "cont.outside.loop");
1140 else
1141 log.error(pos, "break.outside.switch.loop");
1142 return null;
1143 }
1145 public void visitReturn(JCReturn tree) {
1146 // Check that there is an enclosing method which is
1147 // nested within than the enclosing class.
1148 if (env.enclMethod == null ||
1149 env.enclMethod.sym.owner != env.enclClass.sym) {
1150 log.error(tree.pos(), "ret.outside.meth");
1152 } else {
1153 // Attribute return expression, if it exists, and check that
1154 // it conforms to result type of enclosing method.
1155 Symbol m = env.enclMethod.sym;
1156 if (m.type.getReturnType().tag == VOID) {
1157 if (tree.expr != null)
1158 log.error(tree.expr.pos(),
1159 "cant.ret.val.from.meth.decl.void");
1160 } else if (tree.expr == null) {
1161 log.error(tree.pos(), "missing.ret.val");
1162 } else {
1163 attribExpr(tree.expr, env, m.type.getReturnType());
1164 }
1165 }
1166 result = null;
1167 }
1169 public void visitThrow(JCThrow tree) {
1170 attribExpr(tree.expr, env, syms.throwableType);
1171 result = null;
1172 }
1174 public void visitAssert(JCAssert tree) {
1175 attribExpr(tree.cond, env, syms.booleanType);
1176 if (tree.detail != null) {
1177 chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1178 }
1179 result = null;
1180 }
1182 /** Visitor method for method invocations.
1183 * NOTE: The method part of an application will have in its type field
1184 * the return type of the method, not the method's type itself!
1185 */
1186 public void visitApply(JCMethodInvocation tree) {
1187 // The local environment of a method application is
1188 // a new environment nested in the current one.
1189 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1191 // The types of the actual method arguments.
1192 List<Type> argtypes;
1194 // The types of the actual method type arguments.
1195 List<Type> typeargtypes = null;
1197 Name methName = TreeInfo.name(tree.meth);
1199 boolean isConstructorCall =
1200 methName == names._this || methName == names._super;
1202 if (isConstructorCall) {
1203 // We are seeing a ...this(...) or ...super(...) call.
1204 // Check that this is the first statement in a constructor.
1205 if (checkFirstConstructorStat(tree, env)) {
1207 // Record the fact
1208 // that this is a constructor call (using isSelfCall).
1209 localEnv.info.isSelfCall = true;
1211 // Attribute arguments, yielding list of argument types.
1212 argtypes = attribArgs(tree.args, localEnv);
1213 typeargtypes = attribTypes(tree.typeargs, localEnv);
1215 // Variable `site' points to the class in which the called
1216 // constructor is defined.
1217 Type site = env.enclClass.sym.type;
1218 if (methName == names._super) {
1219 if (site == syms.objectType) {
1220 log.error(tree.meth.pos(), "no.superclass", site);
1221 site = syms.errType;
1222 } else {
1223 site = types.supertype(site);
1224 }
1225 }
1227 if (site.tag == CLASS) {
1228 if (site.getEnclosingType().tag == CLASS) {
1229 // we are calling a nested class
1231 if (tree.meth.getTag() == JCTree.SELECT) {
1232 JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1234 // We are seeing a prefixed call, of the form
1235 // <expr>.super(...).
1236 // Check that the prefix expression conforms
1237 // to the outer instance type of the class.
1238 chk.checkRefType(qualifier.pos(),
1239 attribExpr(qualifier, localEnv,
1240 site.getEnclosingType()));
1241 } else if (methName == names._super) {
1242 // qualifier omitted; check for existence
1243 // of an appropriate implicit qualifier.
1244 rs.resolveImplicitThis(tree.meth.pos(),
1245 localEnv, site);
1246 }
1247 } else if (tree.meth.getTag() == JCTree.SELECT) {
1248 log.error(tree.meth.pos(), "illegal.qual.not.icls",
1249 site.tsym);
1250 }
1252 // if we're calling a java.lang.Enum constructor,
1253 // prefix the implicit String and int parameters
1254 if (site.tsym == syms.enumSym && allowEnums)
1255 argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1257 // Resolve the called constructor under the assumption
1258 // that we are referring to a superclass instance of the
1259 // current instance (JLS ???).
1260 boolean selectSuperPrev = localEnv.info.selectSuper;
1261 localEnv.info.selectSuper = true;
1262 localEnv.info.varArgs = false;
1263 Symbol sym = rs.resolveConstructor(
1264 tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1265 localEnv.info.selectSuper = selectSuperPrev;
1267 // Set method symbol to resolved constructor...
1268 TreeInfo.setSymbol(tree.meth, sym);
1270 // ...and check that it is legal in the current context.
1271 // (this will also set the tree's type)
1272 Type mpt = newMethTemplate(argtypes, typeargtypes);
1273 checkId(tree.meth, site, sym, localEnv, MTH,
1274 mpt, tree.varargsElement != null);
1275 }
1276 // Otherwise, `site' is an error type and we do nothing
1277 }
1278 result = tree.type = syms.voidType;
1279 } else {
1280 // Otherwise, we are seeing a regular method call.
1281 // Attribute the arguments, yielding list of argument types, ...
1282 argtypes = attribArgs(tree.args, localEnv);
1283 typeargtypes = attribTypes(tree.typeargs, localEnv);
1285 // ... and attribute the method using as a prototype a methodtype
1286 // whose formal argument types is exactly the list of actual
1287 // arguments (this will also set the method symbol).
1288 Type mpt = newMethTemplate(argtypes, typeargtypes);
1289 localEnv.info.varArgs = false;
1290 Type mtype = attribExpr(tree.meth, localEnv, mpt);
1291 if (localEnv.info.varArgs)
1292 assert mtype.isErroneous() || tree.varargsElement != null;
1294 // Compute the result type.
1295 Type restype = mtype.getReturnType();
1296 assert restype.tag != WILDCARD : mtype;
1298 // as a special case, array.clone() has a result that is
1299 // the same as static type of the array being cloned
1300 if (tree.meth.getTag() == JCTree.SELECT &&
1301 allowCovariantReturns &&
1302 methName == names.clone &&
1303 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1304 restype = ((JCFieldAccess) tree.meth).selected.type;
1306 // as a special case, x.getClass() has type Class<? extends |X|>
1307 if (allowGenerics &&
1308 methName == names.getClass && tree.args.isEmpty()) {
1309 Type qualifier = (tree.meth.getTag() == JCTree.SELECT)
1310 ? ((JCFieldAccess) tree.meth).selected.type
1311 : env.enclClass.sym.type;
1312 restype = new
1313 ClassType(restype.getEnclosingType(),
1314 List.<Type>of(new WildcardType(types.erasure(qualifier),
1315 BoundKind.EXTENDS,
1316 syms.boundClass)),
1317 restype.tsym);
1318 }
1320 // Check that value of resulting type is admissible in the
1321 // current context. Also, capture the return type
1322 result = check(tree, capture(restype), VAL, pkind, pt);
1323 }
1324 chk.validate(tree.typeargs);
1325 }
1326 //where
1327 /** Check that given application node appears as first statement
1328 * in a constructor call.
1329 * @param tree The application node
1330 * @param env The environment current at the application.
1331 */
1332 boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1333 JCMethodDecl enclMethod = env.enclMethod;
1334 if (enclMethod != null && enclMethod.name == names.init) {
1335 JCBlock body = enclMethod.body;
1336 if (body.stats.head.getTag() == JCTree.EXEC &&
1337 ((JCExpressionStatement) body.stats.head).expr == tree)
1338 return true;
1339 }
1340 log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1341 TreeInfo.name(tree.meth));
1342 return false;
1343 }
1345 /** Obtain a method type with given argument types.
1346 */
1347 Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
1348 MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
1349 return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1350 }
1352 public void visitNewClass(JCNewClass tree) {
1353 Type owntype = syms.errType;
1355 // The local environment of a class creation is
1356 // a new environment nested in the current one.
1357 Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1359 // The anonymous inner class definition of the new expression,
1360 // if one is defined by it.
1361 JCClassDecl cdef = tree.def;
1363 // If enclosing class is given, attribute it, and
1364 // complete class name to be fully qualified
1365 JCExpression clazz = tree.clazz; // Class field following new
1366 JCExpression clazzid = // Identifier in class field
1367 (clazz.getTag() == JCTree.TYPEAPPLY)
1368 ? ((JCTypeApply) clazz).clazz
1369 : clazz;
1371 JCExpression clazzid1 = clazzid; // The same in fully qualified form
1373 if (tree.encl != null) {
1374 // We are seeing a qualified new, of the form
1375 // <expr>.new C <...> (...) ...
1376 // In this case, we let clazz stand for the name of the
1377 // allocated class C prefixed with the type of the qualifier
1378 // expression, so that we can
1379 // resolve it with standard techniques later. I.e., if
1380 // <expr> has type T, then <expr>.new C <...> (...)
1381 // yields a clazz T.C.
1382 Type encltype = chk.checkRefType(tree.encl.pos(),
1383 attribExpr(tree.encl, env));
1384 clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1385 ((JCIdent) clazzid).name);
1386 if (clazz.getTag() == JCTree.TYPEAPPLY)
1387 clazz = make.at(tree.pos).
1388 TypeApply(clazzid1,
1389 ((JCTypeApply) clazz).arguments);
1390 else
1391 clazz = clazzid1;
1392 // System.out.println(clazz + " generated.");//DEBUG
1393 }
1395 // Attribute clazz expression and store
1396 // symbol + type back into the attributed tree.
1397 Type clazztype = chk.checkClassType(
1398 tree.clazz.pos(), attribType(clazz, env), true);
1399 chk.validate(clazz);
1400 if (tree.encl != null) {
1401 // We have to work in this case to store
1402 // symbol + type back into the attributed tree.
1403 tree.clazz.type = clazztype;
1404 TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1405 clazzid.type = ((JCIdent) clazzid).sym.type;
1406 if (!clazztype.isErroneous()) {
1407 if (cdef != null && clazztype.tsym.isInterface()) {
1408 log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1409 } else if (clazztype.tsym.isStatic()) {
1410 log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1411 }
1412 }
1413 } else if (!clazztype.tsym.isInterface() &&
1414 clazztype.getEnclosingType().tag == CLASS) {
1415 // Check for the existence of an apropos outer instance
1416 rs.resolveImplicitThis(tree.pos(), env, clazztype);
1417 }
1419 // Attribute constructor arguments.
1420 List<Type> argtypes = attribArgs(tree.args, localEnv);
1421 List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1423 // If we have made no mistakes in the class type...
1424 if (clazztype.tag == CLASS) {
1425 // Enums may not be instantiated except implicitly
1426 if (allowEnums &&
1427 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1428 (env.tree.getTag() != JCTree.VARDEF ||
1429 (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1430 ((JCVariableDecl) env.tree).init != tree))
1431 log.error(tree.pos(), "enum.cant.be.instantiated");
1432 // Check that class is not abstract
1433 if (cdef == null &&
1434 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1435 log.error(tree.pos(), "abstract.cant.be.instantiated",
1436 clazztype.tsym);
1437 } else if (cdef != null && clazztype.tsym.isInterface()) {
1438 // Check that no constructor arguments are given to
1439 // anonymous classes implementing an interface
1440 if (!argtypes.isEmpty())
1441 log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1443 if (!typeargtypes.isEmpty())
1444 log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1446 // Error recovery: pretend no arguments were supplied.
1447 argtypes = List.nil();
1448 typeargtypes = List.nil();
1449 }
1451 // Resolve the called constructor under the assumption
1452 // that we are referring to a superclass instance of the
1453 // current instance (JLS ???).
1454 else {
1455 localEnv.info.selectSuper = cdef != null;
1456 localEnv.info.varArgs = false;
1457 tree.constructor = rs.resolveConstructor(
1458 tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
1459 Type ctorType = checkMethod(clazztype,
1460 tree.constructor,
1461 localEnv,
1462 tree.args,
1463 argtypes,
1464 typeargtypes,
1465 localEnv.info.varArgs);
1466 if (localEnv.info.varArgs)
1467 assert ctorType.isErroneous() || tree.varargsElement != null;
1468 }
1470 if (cdef != null) {
1471 // We are seeing an anonymous class instance creation.
1472 // In this case, the class instance creation
1473 // expression
1474 //
1475 // E.new <typeargs1>C<typargs2>(args) { ... }
1476 //
1477 // is represented internally as
1478 //
1479 // E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
1480 //
1481 // This expression is then *transformed* as follows:
1482 //
1483 // (1) add a STATIC flag to the class definition
1484 // if the current environment is static
1485 // (2) add an extends or implements clause
1486 // (3) add a constructor.
1487 //
1488 // For instance, if C is a class, and ET is the type of E,
1489 // the expression
1490 //
1491 // E.new <typeargs1>C<typargs2>(args) { ... }
1492 //
1493 // is translated to (where X is a fresh name and typarams is the
1494 // parameter list of the super constructor):
1495 //
1496 // new <typeargs1>X(<*nullchk*>E, args) where
1497 // X extends C<typargs2> {
1498 // <typarams> X(ET e, args) {
1499 // e.<typeargs1>super(args)
1500 // }
1501 // ...
1502 // }
1503 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1505 if (clazztype.tsym.isInterface()) {
1506 cdef.implementing = List.of(clazz);
1507 } else {
1508 cdef.extending = clazz;
1509 }
1511 attribStat(cdef, localEnv);
1513 // If an outer instance is given,
1514 // prefix it to the constructor arguments
1515 // and delete it from the new expression
1516 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1517 tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1518 argtypes = argtypes.prepend(tree.encl.type);
1519 tree.encl = null;
1520 }
1522 // Reassign clazztype and recompute constructor.
1523 clazztype = cdef.sym.type;
1524 Symbol sym = rs.resolveConstructor(
1525 tree.pos(), localEnv, clazztype, argtypes,
1526 typeargtypes, true, tree.varargsElement != null);
1527 assert sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous();
1528 tree.constructor = sym;
1529 }
1531 if (tree.constructor != null && tree.constructor.kind == MTH)
1532 owntype = clazztype;
1533 }
1534 result = check(tree, owntype, VAL, pkind, pt);
1535 chk.validate(tree.typeargs);
1536 }
1538 /** Make an attributed null check tree.
1539 */
1540 public JCExpression makeNullCheck(JCExpression arg) {
1541 // optimization: X.this is never null; skip null check
1542 Name name = TreeInfo.name(arg);
1543 if (name == names._this || name == names._super) return arg;
1545 int optag = JCTree.NULLCHK;
1546 JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1547 tree.operator = syms.nullcheck;
1548 tree.type = arg.type;
1549 return tree;
1550 }
1552 public void visitNewArray(JCNewArray tree) {
1553 Type owntype = syms.errType;
1554 Type elemtype;
1555 if (tree.elemtype != null) {
1556 elemtype = attribType(tree.elemtype, env);
1557 chk.validate(tree.elemtype);
1558 owntype = elemtype;
1559 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1560 attribExpr(l.head, env, syms.intType);
1561 owntype = new ArrayType(owntype, syms.arrayClass);
1562 }
1563 } else {
1564 // we are seeing an untyped aggregate { ... }
1565 // this is allowed only if the prototype is an array
1566 if (pt.tag == ARRAY) {
1567 elemtype = types.elemtype(pt);
1568 } else {
1569 if (pt.tag != ERROR) {
1570 log.error(tree.pos(), "illegal.initializer.for.type",
1571 pt);
1572 }
1573 elemtype = syms.errType;
1574 }
1575 }
1576 if (tree.elems != null) {
1577 attribExprs(tree.elems, env, elemtype);
1578 owntype = new ArrayType(elemtype, syms.arrayClass);
1579 }
1580 if (!types.isReifiable(elemtype))
1581 log.error(tree.pos(), "generic.array.creation");
1582 result = check(tree, owntype, VAL, pkind, pt);
1583 }
1585 public void visitParens(JCParens tree) {
1586 Type owntype = attribTree(tree.expr, env, pkind, pt);
1587 result = check(tree, owntype, pkind, pkind, pt);
1588 Symbol sym = TreeInfo.symbol(tree);
1589 if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1590 log.error(tree.pos(), "illegal.start.of.type");
1591 }
1593 public void visitAssign(JCAssign tree) {
1594 Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1595 Type capturedType = capture(owntype);
1596 attribExpr(tree.rhs, env, owntype);
1597 result = check(tree, capturedType, VAL, pkind, pt);
1598 }
1600 public void visitAssignop(JCAssignOp tree) {
1601 // Attribute arguments.
1602 Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
1603 Type operand = attribExpr(tree.rhs, env);
1604 // Find operator.
1605 Symbol operator = tree.operator = rs.resolveBinaryOperator(
1606 tree.pos(), tree.getTag() - JCTree.ASGOffset, env,
1607 owntype, operand);
1609 if (operator.kind == MTH) {
1610 chk.checkOperator(tree.pos(),
1611 (OperatorSymbol)operator,
1612 tree.getTag() - JCTree.ASGOffset,
1613 owntype,
1614 operand);
1615 chk.checkDivZero(tree.rhs.pos(), operator, operand);
1616 chk.checkCastable(tree.rhs.pos(),
1617 operator.type.getReturnType(),
1618 owntype);
1619 }
1620 result = check(tree, owntype, VAL, pkind, pt);
1621 }
1623 public void visitUnary(JCUnary tree) {
1624 // Attribute arguments.
1625 Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1626 ? attribTree(tree.arg, env, VAR, Type.noType)
1627 : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
1629 // Find operator.
1630 Symbol operator = tree.operator =
1631 rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
1633 Type owntype = syms.errType;
1634 if (operator.kind == MTH) {
1635 owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1636 ? tree.arg.type
1637 : operator.type.getReturnType();
1638 int opc = ((OperatorSymbol)operator).opcode;
1640 // If the argument is constant, fold it.
1641 if (argtype.constValue() != null) {
1642 Type ctype = cfolder.fold1(opc, argtype);
1643 if (ctype != null) {
1644 owntype = cfolder.coerce(ctype, owntype);
1646 // Remove constant types from arguments to
1647 // conserve space. The parser will fold concatenations
1648 // of string literals; the code here also
1649 // gets rid of intermediate results when some of the
1650 // operands are constant identifiers.
1651 if (tree.arg.type.tsym == syms.stringType.tsym) {
1652 tree.arg.type = syms.stringType;
1653 }
1654 }
1655 }
1656 }
1657 result = check(tree, owntype, VAL, pkind, pt);
1658 }
1660 public void visitBinary(JCBinary tree) {
1661 // Attribute arguments.
1662 Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
1663 Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
1665 // Find operator.
1666 Symbol operator = tree.operator =
1667 rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
1669 Type owntype = syms.errType;
1670 if (operator.kind == MTH) {
1671 owntype = operator.type.getReturnType();
1672 int opc = chk.checkOperator(tree.lhs.pos(),
1673 (OperatorSymbol)operator,
1674 tree.getTag(),
1675 left,
1676 right);
1678 // If both arguments are constants, fold them.
1679 if (left.constValue() != null && right.constValue() != null) {
1680 Type ctype = cfolder.fold2(opc, left, right);
1681 if (ctype != null) {
1682 owntype = cfolder.coerce(ctype, owntype);
1684 // Remove constant types from arguments to
1685 // conserve space. The parser will fold concatenations
1686 // of string literals; the code here also
1687 // gets rid of intermediate results when some of the
1688 // operands are constant identifiers.
1689 if (tree.lhs.type.tsym == syms.stringType.tsym) {
1690 tree.lhs.type = syms.stringType;
1691 }
1692 if (tree.rhs.type.tsym == syms.stringType.tsym) {
1693 tree.rhs.type = syms.stringType;
1694 }
1695 }
1696 }
1698 // Check that argument types of a reference ==, != are
1699 // castable to each other, (JLS???).
1700 if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
1701 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
1702 log.error(tree.pos(), "incomparable.types", left, right);
1703 }
1704 }
1706 chk.checkDivZero(tree.rhs.pos(), operator, right);
1707 }
1708 result = check(tree, owntype, VAL, pkind, pt);
1709 }
1711 public void visitTypeCast(JCTypeCast tree) {
1712 Type clazztype = attribType(tree.clazz, env);
1713 Type exprtype = attribExpr(tree.expr, env, Infer.anyPoly);
1714 Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1715 if (exprtype.constValue() != null)
1716 owntype = cfolder.coerce(exprtype, owntype);
1717 result = check(tree, capture(owntype), VAL, pkind, pt);
1718 }
1720 public void visitTypeTest(JCInstanceOf tree) {
1721 Type exprtype = chk.checkNullOrRefType(
1722 tree.expr.pos(), attribExpr(tree.expr, env));
1723 Type clazztype = chk.checkReifiableReferenceType(
1724 tree.clazz.pos(), attribType(tree.clazz, env));
1725 chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1726 result = check(tree, syms.booleanType, VAL, pkind, pt);
1727 }
1729 public void visitIndexed(JCArrayAccess tree) {
1730 Type owntype = syms.errType;
1731 Type atype = attribExpr(tree.indexed, env);
1732 attribExpr(tree.index, env, syms.intType);
1733 if (types.isArray(atype))
1734 owntype = types.elemtype(atype);
1735 else if (atype.tag != ERROR)
1736 log.error(tree.pos(), "array.req.but.found", atype);
1737 if ((pkind & VAR) == 0) owntype = capture(owntype);
1738 result = check(tree, owntype, VAR, pkind, pt);
1739 }
1741 public void visitIdent(JCIdent tree) {
1742 Symbol sym;
1743 boolean varArgs = false;
1745 // Find symbol
1746 if (pt.tag == METHOD || pt.tag == FORALL) {
1747 // If we are looking for a method, the prototype `pt' will be a
1748 // method type with the type of the call's arguments as parameters.
1749 env.info.varArgs = false;
1750 sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
1751 varArgs = env.info.varArgs;
1752 } else if (tree.sym != null && tree.sym.kind != VAR) {
1753 sym = tree.sym;
1754 } else {
1755 sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
1756 }
1757 tree.sym = sym;
1759 // (1) Also find the environment current for the class where
1760 // sym is defined (`symEnv').
1761 // Only for pre-tiger versions (1.4 and earlier):
1762 // (2) Also determine whether we access symbol out of an anonymous
1763 // class in a this or super call. This is illegal for instance
1764 // members since such classes don't carry a this$n link.
1765 // (`noOuterThisPath').
1766 Env<AttrContext> symEnv = env;
1767 boolean noOuterThisPath = false;
1768 if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
1769 (sym.kind & (VAR | MTH | TYP)) != 0 &&
1770 sym.owner.kind == TYP &&
1771 tree.name != names._this && tree.name != names._super) {
1773 // Find environment in which identifier is defined.
1774 while (symEnv.outer != null &&
1775 !sym.isMemberOf(symEnv.enclClass.sym, types)) {
1776 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
1777 noOuterThisPath = !allowAnonOuterThis;
1778 symEnv = symEnv.outer;
1779 }
1780 }
1782 // If symbol is a variable, ...
1783 if (sym.kind == VAR) {
1784 VarSymbol v = (VarSymbol)sym;
1786 // ..., evaluate its initializer, if it has one, and check for
1787 // illegal forward reference.
1788 checkInit(tree, env, v, false);
1790 // If symbol is a local variable accessed from an embedded
1791 // inner class check that it is final.
1792 if (v.owner.kind == MTH &&
1793 v.owner != env.info.scope.owner &&
1794 (v.flags_field & FINAL) == 0) {
1795 log.error(tree.pos(),
1796 "local.var.accessed.from.icls.needs.final",
1797 v);
1798 }
1800 // If we are expecting a variable (as opposed to a value), check
1801 // that the variable is assignable in the current environment.
1802 if (pkind == VAR)
1803 checkAssignable(tree.pos(), v, null, env);
1804 }
1806 // In a constructor body,
1807 // if symbol is a field or instance method, check that it is
1808 // not accessed before the supertype constructor is called.
1809 if ((symEnv.info.isSelfCall || noOuterThisPath) &&
1810 (sym.kind & (VAR | MTH)) != 0 &&
1811 sym.owner.kind == TYP &&
1812 (sym.flags() & STATIC) == 0) {
1813 chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
1814 }
1815 Env<AttrContext> env1 = env;
1816 if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
1817 // If the found symbol is inaccessible, then it is
1818 // accessed through an enclosing instance. Locate this
1819 // enclosing instance:
1820 while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
1821 env1 = env1.outer;
1822 }
1823 result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
1824 }
1826 public void visitSelect(JCFieldAccess tree) {
1827 // Determine the expected kind of the qualifier expression.
1828 int skind = 0;
1829 if (tree.name == names._this || tree.name == names._super ||
1830 tree.name == names._class)
1831 {
1832 skind = TYP;
1833 } else {
1834 if ((pkind & PCK) != 0) skind = skind | PCK;
1835 if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
1836 if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
1837 }
1839 // Attribute the qualifier expression, and determine its symbol (if any).
1840 Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
1841 if ((pkind & (PCK | TYP)) == 0)
1842 site = capture(site); // Capture field access
1844 // don't allow T.class T[].class, etc
1845 if (skind == TYP) {
1846 Type elt = site;
1847 while (elt.tag == ARRAY)
1848 elt = ((ArrayType)elt).elemtype;
1849 if (elt.tag == TYPEVAR) {
1850 log.error(tree.pos(), "type.var.cant.be.deref");
1851 result = syms.errType;
1852 return;
1853 }
1854 }
1856 // If qualifier symbol is a type or `super', assert `selectSuper'
1857 // for the selection. This is relevant for determining whether
1858 // protected symbols are accessible.
1859 Symbol sitesym = TreeInfo.symbol(tree.selected);
1860 boolean selectSuperPrev = env.info.selectSuper;
1861 env.info.selectSuper =
1862 sitesym != null &&
1863 sitesym.name == names._super;
1865 // If selected expression is polymorphic, strip
1866 // type parameters and remember in env.info.tvars, so that
1867 // they can be added later (in Attr.checkId and Infer.instantiateMethod).
1868 if (tree.selected.type.tag == FORALL) {
1869 ForAll pstype = (ForAll)tree.selected.type;
1870 env.info.tvars = pstype.tvars;
1871 site = tree.selected.type = pstype.qtype;
1872 }
1874 // Determine the symbol represented by the selection.
1875 env.info.varArgs = false;
1876 Symbol sym = selectSym(tree, site, env, pt, pkind);
1877 if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
1878 site = capture(site);
1879 sym = selectSym(tree, site, env, pt, pkind);
1880 }
1881 boolean varArgs = env.info.varArgs;
1882 tree.sym = sym;
1884 if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
1885 while (site.tag == TYPEVAR) site = site.getUpperBound();
1886 site = capture(site);
1887 }
1889 // If that symbol is a variable, ...
1890 if (sym.kind == VAR) {
1891 VarSymbol v = (VarSymbol)sym;
1893 // ..., evaluate its initializer, if it has one, and check for
1894 // illegal forward reference.
1895 checkInit(tree, env, v, true);
1897 // If we are expecting a variable (as opposed to a value), check
1898 // that the variable is assignable in the current environment.
1899 if (pkind == VAR)
1900 checkAssignable(tree.pos(), v, tree.selected, env);
1901 }
1903 // Disallow selecting a type from an expression
1904 if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
1905 tree.type = check(tree.selected, pt,
1906 sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
1907 }
1909 if (isType(sitesym)) {
1910 if (sym.name == names._this) {
1911 // If `C' is the currently compiled class, check that
1912 // C.this' does not appear in a call to a super(...)
1913 if (env.info.isSelfCall &&
1914 site.tsym == env.enclClass.sym) {
1915 chk.earlyRefError(tree.pos(), sym);
1916 }
1917 } else {
1918 // Check if type-qualified fields or methods are static (JLS)
1919 if ((sym.flags() & STATIC) == 0 &&
1920 sym.name != names._super &&
1921 (sym.kind == VAR || sym.kind == MTH)) {
1922 rs.access(rs.new StaticError(sym),
1923 tree.pos(), site, sym.name, true);
1924 }
1925 }
1926 }
1928 // If we are selecting an instance member via a `super', ...
1929 if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
1931 // Check that super-qualified symbols are not abstract (JLS)
1932 rs.checkNonAbstract(tree.pos(), sym);
1934 if (site.isRaw()) {
1935 // Determine argument types for site.
1936 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
1937 if (site1 != null) site = site1;
1938 }
1939 }
1941 env.info.selectSuper = selectSuperPrev;
1942 result = checkId(tree, site, sym, env, pkind, pt, varArgs);
1943 env.info.tvars = List.nil();
1944 }
1945 //where
1946 /** Determine symbol referenced by a Select expression,
1947 *
1948 * @param tree The select tree.
1949 * @param site The type of the selected expression,
1950 * @param env The current environment.
1951 * @param pt The current prototype.
1952 * @param pkind The expected kind(s) of the Select expression.
1953 */
1954 private Symbol selectSym(JCFieldAccess tree,
1955 Type site,
1956 Env<AttrContext> env,
1957 Type pt,
1958 int pkind) {
1959 DiagnosticPosition pos = tree.pos();
1960 Name name = tree.name;
1962 switch (site.tag) {
1963 case PACKAGE:
1964 return rs.access(
1965 rs.findIdentInPackage(env, site.tsym, name, pkind),
1966 pos, site, name, true);
1967 case ARRAY:
1968 case CLASS:
1969 if (pt.tag == METHOD || pt.tag == FORALL) {
1970 return rs.resolveQualifiedMethod(
1971 pos, env, site, name, pt.getParameterTypes(), pt.getTypeArguments());
1972 } else if (name == names._this || name == names._super) {
1973 return rs.resolveSelf(pos, env, site.tsym, name);
1974 } else if (name == names._class) {
1975 // In this case, we have already made sure in
1976 // visitSelect that qualifier expression is a type.
1977 Type t = syms.classType;
1978 List<Type> typeargs = allowGenerics
1979 ? List.of(types.erasure(site))
1980 : List.<Type>nil();
1981 t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
1982 return new VarSymbol(
1983 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
1984 } else {
1985 // We are seeing a plain identifier as selector.
1986 Symbol sym = rs.findIdentInType(env, site, name, pkind);
1987 if ((pkind & ERRONEOUS) == 0)
1988 sym = rs.access(sym, pos, site, name, true);
1989 return sym;
1990 }
1991 case WILDCARD:
1992 throw new AssertionError(tree);
1993 case TYPEVAR:
1994 // Normally, site.getUpperBound() shouldn't be null.
1995 // It should only happen during memberEnter/attribBase
1996 // when determining the super type which *must* be
1997 // done before attributing the type variables. In
1998 // other words, we are seeing this illegal program:
1999 // class B<T> extends A<T.foo> {}
2000 Symbol sym = (site.getUpperBound() != null)
2001 ? selectSym(tree, capture(site.getUpperBound()), env, pt, pkind)
2002 : null;
2003 if (sym == null || isType(sym)) {
2004 log.error(pos, "type.var.cant.be.deref");
2005 return syms.errSymbol;
2006 } else {
2007 return sym;
2008 }
2009 case ERROR:
2010 // preserve identifier names through errors
2011 return new ErrorType(name, site.tsym).tsym;
2012 default:
2013 // The qualifier expression is of a primitive type -- only
2014 // .class is allowed for these.
2015 if (name == names._class) {
2016 // In this case, we have already made sure in Select that
2017 // qualifier expression is a type.
2018 Type t = syms.classType;
2019 Type arg = types.boxedClass(site).type;
2020 t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2021 return new VarSymbol(
2022 STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2023 } else {
2024 log.error(pos, "cant.deref", site);
2025 return syms.errSymbol;
2026 }
2027 }
2028 }
2030 /** Determine type of identifier or select expression and check that
2031 * (1) the referenced symbol is not deprecated
2032 * (2) the symbol's type is safe (@see checkSafe)
2033 * (3) if symbol is a variable, check that its type and kind are
2034 * compatible with the prototype and protokind.
2035 * (4) if symbol is an instance field of a raw type,
2036 * which is being assigned to, issue an unchecked warning if its
2037 * type changes under erasure.
2038 * (5) if symbol is an instance method of a raw type, issue an
2039 * unchecked warning if its argument types change under erasure.
2040 * If checks succeed:
2041 * If symbol is a constant, return its constant type
2042 * else if symbol is a method, return its result type
2043 * otherwise return its type.
2044 * Otherwise return errType.
2045 *
2046 * @param tree The syntax tree representing the identifier
2047 * @param site If this is a select, the type of the selected
2048 * expression, otherwise the type of the current class.
2049 * @param sym The symbol representing the identifier.
2050 * @param env The current environment.
2051 * @param pkind The set of expected kinds.
2052 * @param pt The expected type.
2053 */
2054 Type checkId(JCTree tree,
2055 Type site,
2056 Symbol sym,
2057 Env<AttrContext> env,
2058 int pkind,
2059 Type pt,
2060 boolean useVarargs) {
2061 if (pt.isErroneous()) return syms.errType;
2062 Type owntype; // The computed type of this identifier occurrence.
2063 switch (sym.kind) {
2064 case TYP:
2065 // For types, the computed type equals the symbol's type,
2066 // except for two situations:
2067 owntype = sym.type;
2068 if (owntype.tag == CLASS) {
2069 Type ownOuter = owntype.getEnclosingType();
2071 // (a) If the symbol's type is parameterized, erase it
2072 // because no type parameters were given.
2073 // We recover generic outer type later in visitTypeApply.
2074 if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2075 owntype = types.erasure(owntype);
2076 }
2078 // (b) If the symbol's type is an inner class, then
2079 // we have to interpret its outer type as a superclass
2080 // of the site type. Example:
2081 //
2082 // class Tree<A> { class Visitor { ... } }
2083 // class PointTree extends Tree<Point> { ... }
2084 // ...PointTree.Visitor...
2085 //
2086 // Then the type of the last expression above is
2087 // Tree<Point>.Visitor.
2088 else if (ownOuter.tag == CLASS && site != ownOuter) {
2089 Type normOuter = site;
2090 if (normOuter.tag == CLASS)
2091 normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2092 if (normOuter == null) // perhaps from an import
2093 normOuter = types.erasure(ownOuter);
2094 if (normOuter != ownOuter)
2095 owntype = new ClassType(
2096 normOuter, List.<Type>nil(), owntype.tsym);
2097 }
2098 }
2099 break;
2100 case VAR:
2101 VarSymbol v = (VarSymbol)sym;
2102 // Test (4): if symbol is an instance field of a raw type,
2103 // which is being assigned to, issue an unchecked warning if
2104 // its type changes under erasure.
2105 if (allowGenerics &&
2106 pkind == VAR &&
2107 v.owner.kind == TYP &&
2108 (v.flags() & STATIC) == 0 &&
2109 (site.tag == CLASS || site.tag == TYPEVAR)) {
2110 Type s = types.asOuterSuper(site, v.owner);
2111 if (s != null &&
2112 s.isRaw() &&
2113 !types.isSameType(v.type, v.erasure(types))) {
2114 chk.warnUnchecked(tree.pos(),
2115 "unchecked.assign.to.var",
2116 v, s);
2117 }
2118 }
2119 // The computed type of a variable is the type of the
2120 // variable symbol, taken as a member of the site type.
2121 owntype = (sym.owner.kind == TYP &&
2122 sym.name != names._this && sym.name != names._super)
2123 ? types.memberType(site, sym)
2124 : sym.type;
2126 if (env.info.tvars.nonEmpty()) {
2127 Type owntype1 = new ForAll(env.info.tvars, owntype);
2128 for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2129 if (!owntype.contains(l.head)) {
2130 log.error(tree.pos(), "undetermined.type", owntype1);
2131 owntype1 = syms.errType;
2132 }
2133 owntype = owntype1;
2134 }
2136 // If the variable is a constant, record constant value in
2137 // computed type.
2138 if (v.getConstValue() != null && isStaticReference(tree))
2139 owntype = owntype.constType(v.getConstValue());
2141 if (pkind == VAL) {
2142 owntype = capture(owntype); // capture "names as expressions"
2143 }
2144 break;
2145 case MTH: {
2146 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2147 owntype = checkMethod(site, sym, env, app.args,
2148 pt.getParameterTypes(), pt.getTypeArguments(),
2149 env.info.varArgs);
2150 break;
2151 }
2152 case PCK: case ERR:
2153 owntype = sym.type;
2154 break;
2155 default:
2156 throw new AssertionError("unexpected kind: " + sym.kind +
2157 " in tree " + tree);
2158 }
2160 // Test (1): emit a `deprecation' warning if symbol is deprecated.
2161 // (for constructors, the error was given when the constructor was
2162 // resolved)
2163 if (sym.name != names.init &&
2164 (sym.flags() & DEPRECATED) != 0 &&
2165 (env.info.scope.owner.flags() & DEPRECATED) == 0 &&
2166 sym.outermostClass() != env.info.scope.owner.outermostClass())
2167 chk.warnDeprecated(tree.pos(), sym);
2169 if ((sym.flags() & PROPRIETARY) != 0)
2170 log.strictWarning(tree.pos(), "sun.proprietary", sym);
2172 // Test (3): if symbol is a variable, check that its type and
2173 // kind are compatible with the prototype and protokind.
2174 return check(tree, owntype, sym.kind, pkind, pt);
2175 }
2177 /** Check that variable is initialized and evaluate the variable's
2178 * initializer, if not yet done. Also check that variable is not
2179 * referenced before it is defined.
2180 * @param tree The tree making up the variable reference.
2181 * @param env The current environment.
2182 * @param v The variable's symbol.
2183 */
2184 private void checkInit(JCTree tree,
2185 Env<AttrContext> env,
2186 VarSymbol v,
2187 boolean onlyWarning) {
2188 // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2189 // tree.pos + " " + v.pos + " " +
2190 // Resolve.isStatic(env));//DEBUG
2192 // A forward reference is diagnosed if the declaration position
2193 // of the variable is greater than the current tree position
2194 // and the tree and variable definition occur in the same class
2195 // definition. Note that writes don't count as references.
2196 // This check applies only to class and instance
2197 // variables. Local variables follow different scope rules,
2198 // and are subject to definite assignment checking.
2199 if (v.pos > tree.pos &&
2200 v.owner.kind == TYP &&
2201 canOwnInitializer(env.info.scope.owner) &&
2202 v.owner == env.info.scope.owner.enclClass() &&
2203 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2204 (env.tree.getTag() != JCTree.ASSIGN ||
2205 TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2207 if (!onlyWarning || isStaticEnumField(v)) {
2208 log.error(tree.pos(), "illegal.forward.ref");
2209 } else if (useBeforeDeclarationWarning) {
2210 log.warning(tree.pos(), "forward.ref", v);
2211 }
2212 }
2214 v.getConstValue(); // ensure initializer is evaluated
2216 checkEnumInitializer(tree, env, v);
2217 }
2219 /**
2220 * Check for illegal references to static members of enum. In
2221 * an enum type, constructors and initializers may not
2222 * reference its static members unless they are constant.
2223 *
2224 * @param tree The tree making up the variable reference.
2225 * @param env The current environment.
2226 * @param v The variable's symbol.
2227 * @see JLS 3rd Ed. (8.9 Enums)
2228 */
2229 private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2230 // JLS 3rd Ed.:
2231 //
2232 // "It is a compile-time error to reference a static field
2233 // of an enum type that is not a compile-time constant
2234 // (15.28) from constructors, instance initializer blocks,
2235 // or instance variable initializer expressions of that
2236 // type. It is a compile-time error for the constructors,
2237 // instance initializer blocks, or instance variable
2238 // initializer expressions of an enum constant e to refer
2239 // to itself or to an enum constant of the same type that
2240 // is declared to the right of e."
2241 if (isStaticEnumField(v)) {
2242 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2244 if (enclClass == null || enclClass.owner == null)
2245 return;
2247 // See if the enclosing class is the enum (or a
2248 // subclass thereof) declaring v. If not, this
2249 // reference is OK.
2250 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2251 return;
2253 // If the reference isn't from an initializer, then
2254 // the reference is OK.
2255 if (!Resolve.isInitializer(env))
2256 return;
2258 log.error(tree.pos(), "illegal.enum.static.ref");
2259 }
2260 }
2262 /** Is the given symbol a static, non-constant field of an Enum?
2263 * Note: enum literals should not be regarded as such
2264 */
2265 private boolean isStaticEnumField(VarSymbol v) {
2266 return Flags.isEnum(v.owner) &&
2267 Flags.isStatic(v) &&
2268 !Flags.isConstant(v) &&
2269 v.name != names._class;
2270 }
2272 /** Can the given symbol be the owner of code which forms part
2273 * if class initialization? This is the case if the symbol is
2274 * a type or field, or if the symbol is the synthetic method.
2275 * owning a block.
2276 */
2277 private boolean canOwnInitializer(Symbol sym) {
2278 return
2279 (sym.kind & (VAR | TYP)) != 0 ||
2280 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2281 }
2283 Warner noteWarner = new Warner();
2285 /**
2286 * Check that method arguments conform to its instantation.
2287 **/
2288 public Type checkMethod(Type site,
2289 Symbol sym,
2290 Env<AttrContext> env,
2291 final List<JCExpression> argtrees,
2292 List<Type> argtypes,
2293 List<Type> typeargtypes,
2294 boolean useVarargs) {
2295 // Test (5): if symbol is an instance method of a raw type, issue
2296 // an unchecked warning if its argument types change under erasure.
2297 if (allowGenerics &&
2298 (sym.flags() & STATIC) == 0 &&
2299 (site.tag == CLASS || site.tag == TYPEVAR)) {
2300 Type s = types.asOuterSuper(site, sym.owner);
2301 if (s != null && s.isRaw() &&
2302 !types.isSameTypes(sym.type.getParameterTypes(),
2303 sym.erasure(types).getParameterTypes())) {
2304 chk.warnUnchecked(env.tree.pos(),
2305 "unchecked.call.mbr.of.raw.type",
2306 sym, s);
2307 }
2308 }
2310 // Compute the identifier's instantiated type.
2311 // For methods, we need to compute the instance type by
2312 // Resolve.instantiate from the symbol's type as well as
2313 // any type arguments and value arguments.
2314 noteWarner.warned = false;
2315 Type owntype = rs.instantiate(env,
2316 site,
2317 sym,
2318 argtypes,
2319 typeargtypes,
2320 true,
2321 useVarargs,
2322 noteWarner);
2323 boolean warned = noteWarner.warned;
2325 // If this fails, something went wrong; we should not have
2326 // found the identifier in the first place.
2327 if (owntype == null) {
2328 if (!pt.isErroneous())
2329 log.error(env.tree.pos(),
2330 "internal.error.cant.instantiate",
2331 sym, site,
2332 Type.toString(pt.getParameterTypes()));
2333 owntype = syms.errType;
2334 } else {
2335 // System.out.println("call : " + env.tree);
2336 // System.out.println("method : " + owntype);
2337 // System.out.println("actuals: " + argtypes);
2338 List<Type> formals = owntype.getParameterTypes();
2339 Type last = useVarargs ? formals.last() : null;
2340 if (sym.name==names.init &&
2341 sym.owner == syms.enumSym)
2342 formals = formals.tail.tail;
2343 List<JCExpression> args = argtrees;
2344 while (formals.head != last) {
2345 JCTree arg = args.head;
2346 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2347 assertConvertible(arg, arg.type, formals.head, warn);
2348 warned |= warn.warned;
2349 args = args.tail;
2350 formals = formals.tail;
2351 }
2352 if (useVarargs) {
2353 Type varArg = types.elemtype(last);
2354 while (args.tail != null) {
2355 JCTree arg = args.head;
2356 Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2357 assertConvertible(arg, arg.type, varArg, warn);
2358 warned |= warn.warned;
2359 args = args.tail;
2360 }
2361 } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2362 // non-varargs call to varargs method
2363 Type varParam = owntype.getParameterTypes().last();
2364 Type lastArg = argtypes.last();
2365 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2366 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2367 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2368 types.elemtype(varParam),
2369 varParam);
2370 }
2372 if (warned && sym.type.tag == FORALL) {
2373 String typeargs = "";
2374 if (typeargtypes != null && typeargtypes.nonEmpty()) {
2375 typeargs = "<" + Type.toString(typeargtypes) + ">";
2376 }
2377 chk.warnUnchecked(env.tree.pos(),
2378 "unchecked.meth.invocation.applied",
2379 sym,
2380 sym.location(),
2381 typeargs,
2382 Type.toString(argtypes));
2383 owntype = new MethodType(owntype.getParameterTypes(),
2384 types.erasure(owntype.getReturnType()),
2385 owntype.getThrownTypes(),
2386 syms.methodClass);
2387 }
2388 if (useVarargs) {
2389 JCTree tree = env.tree;
2390 Type argtype = owntype.getParameterTypes().last();
2391 if (!types.isReifiable(argtype))
2392 chk.warnUnchecked(env.tree.pos(),
2393 "unchecked.generic.array.creation",
2394 argtype);
2395 Type elemtype = types.elemtype(argtype);
2396 switch (tree.getTag()) {
2397 case JCTree.APPLY:
2398 ((JCMethodInvocation) tree).varargsElement = elemtype;
2399 break;
2400 case JCTree.NEWCLASS:
2401 ((JCNewClass) tree).varargsElement = elemtype;
2402 break;
2403 default:
2404 throw new AssertionError(""+tree);
2405 }
2406 }
2407 }
2408 return owntype;
2409 }
2411 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2412 if (types.isConvertible(actual, formal, warn))
2413 return;
2415 if (formal.isCompound()
2416 && types.isSubtype(actual, types.supertype(formal))
2417 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2418 return;
2420 if (false) {
2421 // TODO: make assertConvertible work
2422 chk.typeError(tree.pos(), JCDiagnostic.fragment("incompatible.types"), actual, formal);
2423 throw new AssertionError("Tree: " + tree
2424 + " actual:" + actual
2425 + " formal: " + formal);
2426 }
2427 }
2429 public void visitLiteral(JCLiteral tree) {
2430 result = check(
2431 tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2432 }
2433 //where
2434 /** Return the type of a literal with given type tag.
2435 */
2436 Type litType(int tag) {
2437 return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2438 }
2440 public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2441 result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2442 }
2444 public void visitTypeArray(JCArrayTypeTree tree) {
2445 Type etype = attribType(tree.elemtype, env);
2446 Type type = new ArrayType(etype, syms.arrayClass);
2447 result = check(tree, type, TYP, pkind, pt);
2448 }
2450 /** Visitor method for parameterized types.
2451 * Bound checking is left until later, since types are attributed
2452 * before supertype structure is completely known
2453 */
2454 public void visitTypeApply(JCTypeApply tree) {
2455 Type owntype = syms.errType;
2457 // Attribute functor part of application and make sure it's a class.
2458 Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2460 // Attribute type parameters
2461 List<Type> actuals = attribTypes(tree.arguments, env);
2463 if (clazztype.tag == CLASS) {
2464 List<Type> formals = clazztype.tsym.type.getTypeArguments();
2466 if (actuals.length() == formals.length()) {
2467 List<Type> a = actuals;
2468 List<Type> f = formals;
2469 while (a.nonEmpty()) {
2470 a.head = a.head.withTypeVar(f.head);
2471 a = a.tail;
2472 f = f.tail;
2473 }
2474 // Compute the proper generic outer
2475 Type clazzOuter = clazztype.getEnclosingType();
2476 if (clazzOuter.tag == CLASS) {
2477 Type site;
2478 if (tree.clazz.getTag() == JCTree.IDENT) {
2479 site = env.enclClass.sym.type;
2480 } else if (tree.clazz.getTag() == JCTree.SELECT) {
2481 site = ((JCFieldAccess) tree.clazz).selected.type;
2482 } else throw new AssertionError(""+tree);
2483 if (clazzOuter.tag == CLASS && site != clazzOuter) {
2484 if (site.tag == CLASS)
2485 site = types.asOuterSuper(site, clazzOuter.tsym);
2486 if (site == null)
2487 site = types.erasure(clazzOuter);
2488 clazzOuter = site;
2489 }
2490 }
2491 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2492 } else {
2493 if (formals.length() != 0) {
2494 log.error(tree.pos(), "wrong.number.type.args",
2495 Integer.toString(formals.length()));
2496 } else {
2497 log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2498 }
2499 owntype = syms.errType;
2500 }
2501 }
2502 result = check(tree, owntype, TYP, pkind, pt);
2503 }
2505 public void visitTypeParameter(JCTypeParameter tree) {
2506 TypeVar a = (TypeVar)tree.type;
2507 Set<Type> boundSet = new HashSet<Type>();
2508 if (a.bound.isErroneous())
2509 return;
2510 List<Type> bs = types.getBounds(a);
2511 if (tree.bounds.nonEmpty()) {
2512 // accept class or interface or typevar as first bound.
2513 Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2514 boundSet.add(types.erasure(b));
2515 if (b.tag == TYPEVAR) {
2516 // if first bound was a typevar, do not accept further bounds.
2517 if (tree.bounds.tail.nonEmpty()) {
2518 log.error(tree.bounds.tail.head.pos(),
2519 "type.var.may.not.be.followed.by.other.bounds");
2520 tree.bounds = List.of(tree.bounds.head);
2521 a.bound = bs.head;
2522 }
2523 } else {
2524 // if first bound was a class or interface, accept only interfaces
2525 // as further bounds.
2526 for (JCExpression bound : tree.bounds.tail) {
2527 bs = bs.tail;
2528 Type i = checkBase(bs.head, bound, env, false, true, false);
2529 if (i.tag == CLASS)
2530 chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
2531 }
2532 }
2533 }
2534 bs = types.getBounds(a);
2536 // in case of multiple bounds ...
2537 if (bs.length() > 1) {
2538 // ... the variable's bound is a class type flagged COMPOUND
2539 // (see comment for TypeVar.bound).
2540 // In this case, generate a class tree that represents the
2541 // bound class, ...
2542 JCTree extending;
2543 List<JCExpression> implementing;
2544 if ((bs.head.tsym.flags() & INTERFACE) == 0) {
2545 extending = tree.bounds.head;
2546 implementing = tree.bounds.tail;
2547 } else {
2548 extending = null;
2549 implementing = tree.bounds;
2550 }
2551 JCClassDecl cd = make.at(tree.pos).ClassDef(
2552 make.Modifiers(PUBLIC | ABSTRACT),
2553 tree.name, List.<JCTypeParameter>nil(),
2554 extending, implementing, List.<JCTree>nil());
2556 ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
2557 assert (c.flags() & COMPOUND) != 0;
2558 cd.sym = c;
2559 c.sourcefile = env.toplevel.sourcefile;
2561 // ... and attribute the bound class
2562 c.flags_field |= UNATTRIBUTED;
2563 Env<AttrContext> cenv = enter.classEnv(cd, env);
2564 enter.typeEnvs.put(c, cenv);
2565 }
2566 }
2569 public void visitWildcard(JCWildcard tree) {
2570 //- System.err.println("visitWildcard("+tree+");");//DEBUG
2571 Type type = (tree.kind.kind == BoundKind.UNBOUND)
2572 ? syms.objectType
2573 : attribType(tree.inner, env);
2574 result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
2575 tree.kind.kind,
2576 syms.boundClass),
2577 TYP, pkind, pt);
2578 }
2580 public void visitAnnotation(JCAnnotation tree) {
2581 log.error(tree.pos(), "annotation.not.valid.for.type", pt);
2582 result = tree.type = syms.errType;
2583 }
2585 public void visitErroneous(JCErroneous tree) {
2586 if (tree.errs != null)
2587 for (JCTree err : tree.errs)
2588 attribTree(err, env, ERR, pt);
2589 result = tree.type = syms.errType;
2590 }
2592 /** Default visitor method for all other trees.
2593 */
2594 public void visitTree(JCTree tree) {
2595 throw new AssertionError();
2596 }
2598 /** Main method: attribute class definition associated with given class symbol.
2599 * reporting completion failures at the given position.
2600 * @param pos The source position at which completion errors are to be
2601 * reported.
2602 * @param c The class symbol whose definition will be attributed.
2603 */
2604 public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
2605 try {
2606 annotate.flush();
2607 attribClass(c);
2608 } catch (CompletionFailure ex) {
2609 chk.completionError(pos, ex);
2610 }
2611 }
2613 /** Attribute class definition associated with given class symbol.
2614 * @param c The class symbol whose definition will be attributed.
2615 */
2616 void attribClass(ClassSymbol c) throws CompletionFailure {
2617 if (c.type.tag == ERROR) return;
2619 // Check for cycles in the inheritance graph, which can arise from
2620 // ill-formed class files.
2621 chk.checkNonCyclic(null, c.type);
2623 Type st = types.supertype(c.type);
2624 if ((c.flags_field & Flags.COMPOUND) == 0) {
2625 // First, attribute superclass.
2626 if (st.tag == CLASS)
2627 attribClass((ClassSymbol)st.tsym);
2629 // Next attribute owner, if it is a class.
2630 if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
2631 attribClass((ClassSymbol)c.owner);
2632 }
2634 // The previous operations might have attributed the current class
2635 // if there was a cycle. So we test first whether the class is still
2636 // UNATTRIBUTED.
2637 if ((c.flags_field & UNATTRIBUTED) != 0) {
2638 c.flags_field &= ~UNATTRIBUTED;
2640 // Get environment current at the point of class definition.
2641 Env<AttrContext> env = enter.typeEnvs.get(c);
2643 // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
2644 // because the annotations were not available at the time the env was created. Therefore,
2645 // we look up the environment chain for the first enclosing environment for which the
2646 // lint value is set. Typically, this is the parent env, but might be further if there
2647 // are any envs created as a result of TypeParameter nodes.
2648 Env<AttrContext> lintEnv = env;
2649 while (lintEnv.info.lint == null)
2650 lintEnv = lintEnv.next;
2652 // Having found the enclosing lint value, we can initialize the lint value for this class
2653 env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
2655 Lint prevLint = chk.setLint(env.info.lint);
2656 JavaFileObject prev = log.useSource(c.sourcefile);
2658 try {
2659 // java.lang.Enum may not be subclassed by a non-enum
2660 if (st.tsym == syms.enumSym &&
2661 ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
2662 log.error(env.tree.pos(), "enum.no.subclassing");
2664 // Enums may not be extended by source-level classes
2665 if (st.tsym != null &&
2666 ((st.tsym.flags_field & Flags.ENUM) != 0) &&
2667 ((c.flags_field & Flags.ENUM) == 0) &&
2668 !target.compilerBootstrap(c)) {
2669 log.error(env.tree.pos(), "enum.types.not.extensible");
2670 }
2671 attribClassBody(env, c);
2673 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
2674 } finally {
2675 log.useSource(prev);
2676 chk.setLint(prevLint);
2677 }
2679 }
2680 }
2682 public void visitImport(JCImport tree) {
2683 // nothing to do
2684 }
2686 /** Finish the attribution of a class. */
2687 private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
2688 JCClassDecl tree = (JCClassDecl)env.tree;
2689 assert c == tree.sym;
2691 // Validate annotations
2692 chk.validateAnnotations(tree.mods.annotations, c);
2694 // Validate type parameters, supertype and interfaces.
2695 attribBounds(tree.typarams);
2696 chk.validateTypeParams(tree.typarams);
2697 chk.validate(tree.extending);
2698 chk.validate(tree.implementing);
2700 // If this is a non-abstract class, check that it has no abstract
2701 // methods or unimplemented methods of an implemented interface.
2702 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
2703 if (!relax)
2704 chk.checkAllDefined(tree.pos(), c);
2705 }
2707 if ((c.flags() & ANNOTATION) != 0) {
2708 if (tree.implementing.nonEmpty())
2709 log.error(tree.implementing.head.pos(),
2710 "cant.extend.intf.annotation");
2711 if (tree.typarams.nonEmpty())
2712 log.error(tree.typarams.head.pos(),
2713 "intf.annotation.cant.have.type.params");
2714 } else {
2715 // Check that all extended classes and interfaces
2716 // are compatible (i.e. no two define methods with same arguments
2717 // yet different return types). (JLS 8.4.6.3)
2718 chk.checkCompatibleSupertypes(tree.pos(), c.type);
2719 }
2721 // Check that class does not import the same parameterized interface
2722 // with two different argument lists.
2723 chk.checkClassBounds(tree.pos(), c.type);
2725 tree.type = c.type;
2727 boolean assertsEnabled = false;
2728 assert assertsEnabled = true;
2729 if (assertsEnabled) {
2730 for (List<JCTypeParameter> l = tree.typarams;
2731 l.nonEmpty(); l = l.tail)
2732 assert env.info.scope.lookup(l.head.name).scope != null;
2733 }
2735 // Check that a generic class doesn't extend Throwable
2736 if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
2737 log.error(tree.extending.pos(), "generic.throwable");
2739 // Check that all methods which implement some
2740 // method conform to the method they implement.
2741 chk.checkImplementations(tree);
2743 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2744 // Attribute declaration
2745 attribStat(l.head, env);
2746 // Check that declarations in inner classes are not static (JLS 8.1.2)
2747 // Make an exception for static constants.
2748 if (c.owner.kind != PCK &&
2749 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
2750 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
2751 Symbol sym = null;
2752 if (l.head.getTag() == JCTree.VARDEF) sym = ((JCVariableDecl) l.head).sym;
2753 if (sym == null ||
2754 sym.kind != VAR ||
2755 ((VarSymbol) sym).getConstValue() == null)
2756 log.error(l.head.pos(), "icls.cant.have.static.decl");
2757 }
2758 }
2760 // Check for cycles among non-initial constructors.
2761 chk.checkCyclicConstructors(tree);
2763 // Check for cycles among annotation elements.
2764 chk.checkNonCyclicElements(tree);
2766 // Check for proper use of serialVersionUID
2767 if (env.info.lint.isEnabled(Lint.LintCategory.SERIAL) &&
2768 isSerializable(c) &&
2769 (c.flags() & Flags.ENUM) == 0 &&
2770 (c.flags() & ABSTRACT) == 0) {
2771 checkSerialVersionUID(tree, c);
2772 }
2773 }
2774 // where
2775 /** check if a class is a subtype of Serializable, if that is available. */
2776 private boolean isSerializable(ClassSymbol c) {
2777 try {
2778 syms.serializableType.complete();
2779 }
2780 catch (CompletionFailure e) {
2781 return false;
2782 }
2783 return types.isSubtype(c.type, syms.serializableType);
2784 }
2786 /** Check that an appropriate serialVersionUID member is defined. */
2787 private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
2789 // check for presence of serialVersionUID
2790 Scope.Entry e = c.members().lookup(names.serialVersionUID);
2791 while (e.scope != null && e.sym.kind != VAR) e = e.next();
2792 if (e.scope == null) {
2793 log.warning(tree.pos(), "missing.SVUID", c);
2794 return;
2795 }
2797 // check that it is static final
2798 VarSymbol svuid = (VarSymbol)e.sym;
2799 if ((svuid.flags() & (STATIC | FINAL)) !=
2800 (STATIC | FINAL))
2801 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
2803 // check that it is long
2804 else if (svuid.type.tag != TypeTags.LONG)
2805 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
2807 // check constant
2808 else if (svuid.getConstValue() == null)
2809 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
2810 }
2812 private Type capture(Type type) {
2813 return types.capture(type);
2814 }
2815 }
