duke@1: /*
ohair@554:  * Copyright (c) 1999, 2009, Oracle and/or its affiliates. All rights reserved.
duke@1:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1:  *
duke@1:  * This code is free software; you can redistribute it and/or modify it
duke@1:  * under the terms of the GNU General Public License version 2 only, as
ohair@554:  * published by the Free Software Foundation.  Oracle designates this
duke@1:  * particular file as subject to the "Classpath" exception as provided
ohair@554:  * by Oracle in the LICENSE file that accompanied this code.
duke@1:  *
duke@1:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@1:  * version 2 for more details (a copy is included in the LICENSE file that
duke@1:  * accompanied this code).
duke@1:  *
duke@1:  * You should have received a copy of the GNU General Public License version
duke@1:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@1:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1:  *
ohair@554:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554:  * or visit www.oracle.com if you need additional information or have any
ohair@554:  * questions.
duke@1:  */
duke@1: 
duke@1: package com.sun.tools.javac.comp;
duke@1: 
duke@1: import java.util.*;
duke@1: import java.util.Set;
duke@1: 
duke@1: import com.sun.tools.javac.code.*;
duke@1: import com.sun.tools.javac.jvm.*;
duke@1: import com.sun.tools.javac.tree.*;
duke@1: import com.sun.tools.javac.util.*;
duke@1: import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
duke@1: import com.sun.tools.javac.util.List;
duke@1: 
duke@1: import com.sun.tools.javac.tree.JCTree.*;
duke@1: import com.sun.tools.javac.code.Lint;
duke@1: import com.sun.tools.javac.code.Lint.LintCategory;
duke@1: import com.sun.tools.javac.code.Type.*;
duke@1: import com.sun.tools.javac.code.Symbol.*;
duke@1: 
duke@1: import static com.sun.tools.javac.code.Flags.*;
duke@1: import static com.sun.tools.javac.code.Kinds.*;
duke@1: import static com.sun.tools.javac.code.TypeTags.*;
duke@1: 
duke@1: /** Type checking helper class for the attribution phase.
duke@1:  *
jjg@581:  *  <p><b>This is NOT part of any supported API.
jjg@581:  *  If you write code that depends on this, you do so at your own risk.
duke@1:  *  This code and its internal interfaces are subject to change or
duke@1:  *  deletion without notice.</b>
duke@1:  */
duke@1: public class Check {
duke@1:     protected static final Context.Key<Check> checkKey =
duke@1:         new Context.Key<Check>();
duke@1: 
jjg@113:     private final Names names;
duke@1:     private final Log log;
duke@1:     private final Symtab syms;
duke@1:     private final Infer infer;
duke@1:     private final Types types;
mcimadamore@89:     private final JCDiagnostic.Factory diags;
duke@1:     private final boolean skipAnnotations;
mcimadamore@359:     private boolean warnOnSyntheticConflicts;
jjg@576:     private boolean suppressAbortOnBadClassFile;
duke@1:     private final TreeInfo treeinfo;
duke@1: 
duke@1:     // The set of lint options currently in effect. It is initialized
duke@1:     // from the context, and then is set/reset as needed by Attr as it
duke@1:     // visits all the various parts of the trees during attribution.
duke@1:     private Lint lint;
duke@1: 
duke@1:     public static Check instance(Context context) {
duke@1:         Check instance = context.get(checkKey);
duke@1:         if (instance == null)
duke@1:             instance = new Check(context);
duke@1:         return instance;
duke@1:     }
duke@1: 
duke@1:     protected Check(Context context) {
duke@1:         context.put(checkKey, this);
duke@1: 
jjg@113:         names = Names.instance(context);
duke@1:         log = Log.instance(context);
duke@1:         syms = Symtab.instance(context);
duke@1:         infer = Infer.instance(context);
duke@1:         this.types = Types.instance(context);
mcimadamore@89:         diags = JCDiagnostic.Factory.instance(context);
duke@1:         Options options = Options.instance(context);
duke@1:         lint = Lint.instance(context);
duke@1:         treeinfo = TreeInfo.instance(context);
duke@1: 
duke@1:         Source source = Source.instance(context);
duke@1:         allowGenerics = source.allowGenerics();
duke@1:         allowAnnotations = source.allowAnnotations();
jjg@398:         allowCovariantReturns = source.allowCovariantReturns();
duke@1:         complexInference = options.get("-complexinference") != null;
duke@1:         skipAnnotations = options.get("skipAnnotations") != null;
mcimadamore@359:         warnOnSyntheticConflicts = options.get("warnOnSyntheticConflicts") != null;
jjg@576:         suppressAbortOnBadClassFile = options.get("suppressAbortOnBadClassFile") != null;
duke@1: 
jjg@398:         Target target = Target.instance(context);
jjg@398:         syntheticNameChar = target.syntheticNameChar();
jjg@398: 
duke@1:         boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
duke@1:         boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
mcimadamore@580:         boolean verboseVarargs = lint.isEnabled(LintCategory.VARARGS);
jjg@377:         boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
jjg@60:         boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
duke@1: 
jjg@60:         deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
jjg@60:                 enforceMandatoryWarnings, "deprecated");
jjg@60:         uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
jjg@60:                 enforceMandatoryWarnings, "unchecked");
mcimadamore@580:         unsafeVarargsHandler = new MandatoryWarningHandler(log, verboseVarargs,
mcimadamore@580:                 enforceMandatoryWarnings, "varargs");
jjg@377:         sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
jjg@377:                 enforceMandatoryWarnings, "sunapi");
duke@1:     }
duke@1: 
duke@1:     /** Switch: generics enabled?
duke@1:      */
duke@1:     boolean allowGenerics;
duke@1: 
duke@1:     /** Switch: annotations enabled?
duke@1:      */
duke@1:     boolean allowAnnotations;
duke@1: 
jjg@398:     /** Switch: covariant returns enabled?
jjg@398:      */
jjg@398:     boolean allowCovariantReturns;
jjg@398: 
duke@1:     /** Switch: -complexinference option set?
duke@1:      */
duke@1:     boolean complexInference;
duke@1: 
jjg@398:     /** Character for synthetic names
jjg@398:      */
jjg@398:     char syntheticNameChar;
jjg@398: 
duke@1:     /** A table mapping flat names of all compiled classes in this run to their
duke@1:      *  symbols; maintained from outside.
duke@1:      */
duke@1:     public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
duke@1: 
duke@1:     /** A handler for messages about deprecated usage.
duke@1:      */
duke@1:     private MandatoryWarningHandler deprecationHandler;
duke@1: 
duke@1:     /** A handler for messages about unchecked or unsafe usage.
duke@1:      */
duke@1:     private MandatoryWarningHandler uncheckedHandler;
duke@1: 
mcimadamore@580:     /** A handler for messages about unchecked or unsafe vararg method decl.
mcimadamore@580:      */
mcimadamore@580:     private MandatoryWarningHandler unsafeVarargsHandler;
mcimadamore@580: 
jjg@582:     /** A handler for messages about using proprietary API.
jjg@377:      */
jjg@377:     private MandatoryWarningHandler sunApiHandler;
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Errors and Warnings
duke@1:  **************************************************************************/
duke@1: 
duke@1:     Lint setLint(Lint newLint) {
duke@1:         Lint prev = lint;
duke@1:         lint = newLint;
duke@1:         return prev;
duke@1:     }
duke@1: 
duke@1:     /** Warn about deprecated symbol.
duke@1:      *  @param pos        Position to be used for error reporting.
duke@1:      *  @param sym        The deprecated symbol.
duke@1:      */
duke@1:     void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
duke@1:         if (!lint.isSuppressed(LintCategory.DEPRECATION))
duke@1:             deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
duke@1:     }
duke@1: 
duke@1:     /** Warn about unchecked operation.
duke@1:      *  @param pos        Position to be used for error reporting.
duke@1:      *  @param msg        A string describing the problem.
duke@1:      */
duke@1:     public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
duke@1:         if (!lint.isSuppressed(LintCategory.UNCHECKED))
duke@1:             uncheckedHandler.report(pos, msg, args);
duke@1:     }
duke@1: 
mcimadamore@580:     /** Warn about unsafe vararg method decl.
mcimadamore@580:      *  @param pos        Position to be used for error reporting.
mcimadamore@580:      *  @param sym        The deprecated symbol.
mcimadamore@580:      */
mcimadamore@580:     void warnUnsafeVararg(DiagnosticPosition pos, Type elemType) {
mcimadamore@580:         if (!lint.isSuppressed(LintCategory.VARARGS))
mcimadamore@580:             unsafeVarargsHandler.report(pos, "varargs.non.reifiable.type", elemType);
mcimadamore@580:     }
mcimadamore@580: 
jjg@582:     /** Warn about using proprietary API.
jjg@377:      *  @param pos        Position to be used for error reporting.
jjg@377:      *  @param msg        A string describing the problem.
jjg@377:      */
jjg@377:     public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
jjg@377:         if (!lint.isSuppressed(LintCategory.SUNAPI))
jjg@377:             sunApiHandler.report(pos, msg, args);
jjg@377:     }
jjg@377: 
jjg@505:     public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
jjg@505:         if (lint.isEnabled(LintCategory.STATIC))
jjg@505:             log.warning(pos, msg, args);
jjg@505:     }
jjg@505: 
duke@1:     /**
duke@1:      * Report any deferred diagnostics.
duke@1:      */
duke@1:     public void reportDeferredDiagnostics() {
duke@1:         deprecationHandler.reportDeferredDiagnostic();
duke@1:         uncheckedHandler.reportDeferredDiagnostic();
mcimadamore@580:         unsafeVarargsHandler.reportDeferredDiagnostic();
jjg@377:         sunApiHandler.reportDeferredDiagnostic();
duke@1:     }
duke@1: 
duke@1: 
duke@1:     /** Report a failure to complete a class.
duke@1:      *  @param pos        Position to be used for error reporting.
duke@1:      *  @param ex         The failure to report.
duke@1:      */
duke@1:     public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
jjg@12:         log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
jjg@576:         if (ex instanceof ClassReader.BadClassFile
jjg@576:                 && !suppressAbortOnBadClassFile) throw new Abort();
duke@1:         else return syms.errType;
duke@1:     }
duke@1: 
duke@1:     /** Report a type error.
duke@1:      *  @param pos        Position to be used for error reporting.
duke@1:      *  @param problem    A string describing the error.
duke@1:      *  @param found      The type that was found.
duke@1:      *  @param req        The type that was required.
duke@1:      */
duke@1:     Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
duke@1:         log.error(pos, "prob.found.req",
duke@1:                   problem, found, req);
jjg@110:         return types.createErrorType(found);
duke@1:     }
duke@1: 
duke@1:     Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
duke@1:         log.error(pos, "prob.found.req.1", problem, found, req, explanation);
jjg@110:         return types.createErrorType(found);
duke@1:     }
duke@1: 
duke@1:     /** Report an error that wrong type tag was found.
duke@1:      *  @param pos        Position to be used for error reporting.
duke@1:      *  @param required   An internationalized string describing the type tag
duke@1:      *                    required.
duke@1:      *  @param found      The type that was found.
duke@1:      */
duke@1:     Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
jrose@267:         // this error used to be raised by the parser,
jrose@267:         // but has been delayed to this point:
jrose@267:         if (found instanceof Type && ((Type)found).tag == VOID) {
jrose@267:             log.error(pos, "illegal.start.of.type");
jrose@267:             return syms.errType;
jrose@267:         }
duke@1:         log.error(pos, "type.found.req", found, required);
jjg@110:         return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
duke@1:     }
duke@1: 
duke@1:     /** Report an error that symbol cannot be referenced before super
duke@1:      *  has been called.
duke@1:      *  @param pos        Position to be used for error reporting.
duke@1:      *  @param sym        The referenced symbol.
duke@1:      */
duke@1:     void earlyRefError(DiagnosticPosition pos, Symbol sym) {
duke@1:         log.error(pos, "cant.ref.before.ctor.called", sym);
duke@1:     }
duke@1: 
duke@1:     /** Report duplicate declaration error.
duke@1:      */
duke@1:     void duplicateError(DiagnosticPosition pos, Symbol sym) {
duke@1:         if (!sym.type.isErroneous()) {
duke@1:             log.error(pos, "already.defined", sym, sym.location());
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Report array/varargs duplicate declaration
duke@1:      */
duke@1:     void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
duke@1:         if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
duke@1:             log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
duke@1:         }
duke@1:     }
duke@1: 
duke@1: /* ************************************************************************
duke@1:  * duplicate declaration checking
duke@1:  *************************************************************************/
duke@1: 
duke@1:     /** Check that variable does not hide variable with same name in
duke@1:      *  immediately enclosing local scope.
duke@1:      *  @param pos           Position for error reporting.
duke@1:      *  @param v             The symbol.
duke@1:      *  @param s             The scope.
duke@1:      */
duke@1:     void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
duke@1:         if (s.next != null) {
duke@1:             for (Scope.Entry e = s.next.lookup(v.name);
duke@1:                  e.scope != null && e.sym.owner == v.owner;
duke@1:                  e = e.next()) {
duke@1:                 if (e.sym.kind == VAR &&
duke@1:                     (e.sym.owner.kind & (VAR | MTH)) != 0 &&
duke@1:                     v.name != names.error) {
duke@1:                     duplicateError(pos, e.sym);
duke@1:                     return;
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Check that a class or interface does not hide a class or
duke@1:      *  interface with same name in immediately enclosing local scope.
duke@1:      *  @param pos           Position for error reporting.
duke@1:      *  @param c             The symbol.
duke@1:      *  @param s             The scope.
duke@1:      */
duke@1:     void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
duke@1:         if (s.next != null) {
duke@1:             for (Scope.Entry e = s.next.lookup(c.name);
duke@1:                  e.scope != null && e.sym.owner == c.owner;
duke@1:                  e = e.next()) {
duke@1:                 if (e.sym.kind == TYP &&
duke@1:                     (e.sym.owner.kind & (VAR | MTH)) != 0 &&
duke@1:                     c.name != names.error) {
duke@1:                     duplicateError(pos, e.sym);
duke@1:                     return;
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Check that class does not have the same name as one of
duke@1:      *  its enclosing classes, or as a class defined in its enclosing scope.
duke@1:      *  return true if class is unique in its enclosing scope.
duke@1:      *  @param pos           Position for error reporting.
duke@1:      *  @param name          The class name.
duke@1:      *  @param s             The enclosing scope.
duke@1:      */
duke@1:     boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
duke@1:         for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
duke@1:             if (e.sym.kind == TYP && e.sym.name != names.error) {
duke@1:                 duplicateError(pos, e.sym);
duke@1:                 return false;
duke@1:             }
duke@1:         }
duke@1:         for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
duke@1:             if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
duke@1:                 duplicateError(pos, sym);
duke@1:                 return true;
duke@1:             }
duke@1:         }
duke@1:         return true;
duke@1:     }
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Class name generation
duke@1:  **************************************************************************/
duke@1: 
duke@1:     /** Return name of local class.
duke@1:      *  This is of the form    <enclClass> $ n <classname>
duke@1:      *  where
duke@1:      *    enclClass is the flat name of the enclosing class,
duke@1:      *    classname is the simple name of the local class
duke@1:      */
duke@1:     Name localClassName(ClassSymbol c) {
duke@1:         for (int i=1; ; i++) {
duke@1:             Name flatname = names.
duke@1:                 fromString("" + c.owner.enclClass().flatname +
jjg@398:                            syntheticNameChar + i +
duke@1:                            c.name);
duke@1:             if (compiled.get(flatname) == null) return flatname;
duke@1:         }
duke@1:     }
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Type Checking
duke@1:  **************************************************************************/
duke@1: 
duke@1:     /** Check that a given type is assignable to a given proto-type.
duke@1:      *  If it is, return the type, otherwise return errType.
duke@1:      *  @param pos        Position to be used for error reporting.
duke@1:      *  @param found      The type that was found.
duke@1:      *  @param req        The type that was required.
duke@1:      */
duke@1:     Type checkType(DiagnosticPosition pos, Type found, Type req) {
duke@1:         if (req.tag == ERROR)
duke@1:             return req;
mcimadamore@536:         if (found.tag == FORALL)
mcimadamore@536:             return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
duke@1:         if (req.tag == NONE)
duke@1:             return found;
duke@1:         if (types.isAssignable(found, req, convertWarner(pos, found, req)))
duke@1:             return found;
duke@1:         if (found.tag <= DOUBLE && req.tag <= DOUBLE)
mcimadamore@89:             return typeError(pos, diags.fragment("possible.loss.of.precision"), found, req);
duke@1:         if (found.isSuperBound()) {
duke@1:             log.error(pos, "assignment.from.super-bound", found);
jjg@110:             return types.createErrorType(found);
duke@1:         }
duke@1:         if (req.isExtendsBound()) {
duke@1:             log.error(pos, "assignment.to.extends-bound", req);
jjg@110:             return types.createErrorType(found);
duke@1:         }
mcimadamore@89:         return typeError(pos, diags.fragment("incompatible.types"), found, req);
duke@1:     }
duke@1: 
duke@1:     /** Instantiate polymorphic type to some prototype, unless
duke@1:      *  prototype is `anyPoly' in which case polymorphic type
duke@1:      *  is returned unchanged.
duke@1:      */
mcimadamore@383:     Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) throws Infer.NoInstanceException {
duke@1:         if (pt == Infer.anyPoly && complexInference) {
duke@1:             return t;
duke@1:         } else if (pt == Infer.anyPoly || pt.tag == NONE) {
duke@1:             Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
duke@1:             return instantiatePoly(pos, t, newpt, warn);
duke@1:         } else if (pt.tag == ERROR) {
duke@1:             return pt;
duke@1:         } else {
mcimadamore@536:             try {
mcimadamore@536:                 return infer.instantiateExpr(t, pt, warn);
mcimadamore@536:             } catch (Infer.NoInstanceException ex) {
mcimadamore@536:                 if (ex.isAmbiguous) {
mcimadamore@536:                     JCDiagnostic d = ex.getDiagnostic();
mcimadamore@536:                     log.error(pos,
mcimadamore@536:                               "undetermined.type" + (d!=null ? ".1" : ""),
mcimadamore@536:                               t, d);
mcimadamore@536:                     return types.createErrorType(pt);
mcimadamore@536:                 } else {
mcimadamore@536:                     JCDiagnostic d = ex.getDiagnostic();
mcimadamore@536:                     return typeError(pos,
mcimadamore@536:                                      diags.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
mcimadamore@536:                                      t, pt);
mcimadamore@536:                 }
mcimadamore@536:             } catch (Infer.InvalidInstanceException ex) {
mcimadamore@536:                 JCDiagnostic d = ex.getDiagnostic();
mcimadamore@536:                 log.error(pos, "invalid.inferred.types", t.tvars, d);
mcimadamore@536:                 return types.createErrorType(pt);
mcimadamore@536:             }
duke@1:         }
mcimadamore@536:     }
duke@1: 
duke@1:     /** Check that a given type can be cast to a given target type.
duke@1:      *  Return the result of the cast.
duke@1:      *  @param pos        Position to be used for error reporting.
duke@1:      *  @param found      The type that is being cast.
duke@1:      *  @param req        The target type of the cast.
duke@1:      */
duke@1:     Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
duke@1:         if (found.tag == FORALL) {
duke@1:             instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
duke@1:             return req;
duke@1:         } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
duke@1:             return req;
duke@1:         } else {
duke@1:             return typeError(pos,
mcimadamore@89:                              diags.fragment("inconvertible.types"),
duke@1:                              found, req);
duke@1:         }
duke@1:     }
duke@1: //where
duke@1:         /** Is type a type variable, or a (possibly multi-dimensional) array of
duke@1:          *  type variables?
duke@1:          */
duke@1:         boolean isTypeVar(Type t) {
duke@1:             return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
duke@1:         }
duke@1: 
duke@1:     /** Check that a type is within some bounds.
duke@1:      *
duke@1:      *  Used in TypeApply to verify that, e.g., X in V<X> is a valid
duke@1:      *  type argument.
duke@1:      *  @param pos           Position to be used for error reporting.
duke@1:      *  @param a             The type that should be bounded by bs.
duke@1:      *  @param bs            The bound.
duke@1:      */
duke@1:     private void checkExtends(DiagnosticPosition pos, Type a, TypeVar bs) {
mcimadamore@154:          if (a.isUnbound()) {
mcimadamore@154:              return;
mcimadamore@154:          } else if (a.tag != WILDCARD) {
mcimadamore@154:              a = types.upperBound(a);
mcimadamore@154:              for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
mcimadamore@154:                  if (!types.isSubtype(a, l.head)) {
mcimadamore@154:                      log.error(pos, "not.within.bounds", a);
mcimadamore@154:                      return;
mcimadamore@154:                  }
mcimadamore@154:              }
mcimadamore@154:          } else if (a.isExtendsBound()) {
mcimadamore@154:              if (!types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings))
mcimadamore@154:                  log.error(pos, "not.within.bounds", a);
mcimadamore@154:          } else if (a.isSuperBound()) {
mcimadamore@154:              if (types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound()))
mcimadamore@154:                  log.error(pos, "not.within.bounds", a);
mcimadamore@154:          }
mcimadamore@154:      }
mcimadamore@154: 
mcimadamore@154:     /** Check that a type is within some bounds.
mcimadamore@154:      *
mcimadamore@154:      *  Used in TypeApply to verify that, e.g., X in V<X> is a valid
mcimadamore@154:      *  type argument.
mcimadamore@154:      *  @param pos           Position to be used for error reporting.
mcimadamore@154:      *  @param a             The type that should be bounded by bs.
mcimadamore@154:      *  @param bs            The bound.
mcimadamore@154:      */
mcimadamore@154:     private void checkCapture(JCTypeApply tree) {
mcimadamore@154:         List<JCExpression> args = tree.getTypeArguments();
mcimadamore@154:         for (Type arg : types.capture(tree.type).getTypeArguments()) {
mcimadamore@154:             if (arg.tag == TYPEVAR && arg.getUpperBound().isErroneous()) {
mcimadamore@154:                 log.error(args.head.pos, "not.within.bounds", args.head.type);
mcimadamore@154:                 break;
mcimadamore@79:             }
mcimadamore@154:             args = args.tail;
mcimadamore@79:         }
mcimadamore@154:      }
duke@1: 
duke@1:     /** Check that type is different from 'void'.
duke@1:      *  @param pos           Position to be used for error reporting.
duke@1:      *  @param t             The type to be checked.
duke@1:      */
duke@1:     Type checkNonVoid(DiagnosticPosition pos, Type t) {
duke@1:         if (t.tag == VOID) {
duke@1:             log.error(pos, "void.not.allowed.here");
jjg@110:             return types.createErrorType(t);
duke@1:         } else {
duke@1:             return t;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Check that type is a class or interface type.
duke@1:      *  @param pos           Position to be used for error reporting.
duke@1:      *  @param t             The type to be checked.
duke@1:      */
duke@1:     Type checkClassType(DiagnosticPosition pos, Type t) {
duke@1:         if (t.tag != CLASS && t.tag != ERROR)
duke@1:             return typeTagError(pos,
mcimadamore@89:                                 diags.fragment("type.req.class"),
duke@1:                                 (t.tag == TYPEVAR)
mcimadamore@89:                                 ? diags.fragment("type.parameter", t)
duke@1:                                 : t);
duke@1:         else
duke@1:             return t;
duke@1:     }
duke@1: 
duke@1:     /** Check that type is a class or interface type.
duke@1:      *  @param pos           Position to be used for error reporting.
duke@1:      *  @param t             The type to be checked.
duke@1:      *  @param noBounds    True if type bounds are illegal here.
duke@1:      */
duke@1:     Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
duke@1:         t = checkClassType(pos, t);
duke@1:         if (noBounds && t.isParameterized()) {
duke@1:             List<Type> args = t.getTypeArguments();
duke@1:             while (args.nonEmpty()) {
duke@1:                 if (args.head.tag == WILDCARD)
duke@1:                     return typeTagError(pos,
jjg@598:                                         diags.fragment("type.req.exact"),
duke@1:                                         args.head);
duke@1:                 args = args.tail;
duke@1:             }
duke@1:         }
duke@1:         return t;
duke@1:     }
duke@1: 
duke@1:     /** Check that type is a reifiable class, interface or array type.
duke@1:      *  @param pos           Position to be used for error reporting.
duke@1:      *  @param t             The type to be checked.
duke@1:      */
duke@1:     Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
duke@1:         if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
duke@1:             return typeTagError(pos,
mcimadamore@89:                                 diags.fragment("type.req.class.array"),
duke@1:                                 t);
duke@1:         } else if (!types.isReifiable(t)) {
duke@1:             log.error(pos, "illegal.generic.type.for.instof");
jjg@110:             return types.createErrorType(t);
duke@1:         } else {
duke@1:             return t;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Check that type is a reference type, i.e. a class, interface or array type
duke@1:      *  or a type variable.
duke@1:      *  @param pos           Position to be used for error reporting.
duke@1:      *  @param t             The type to be checked.
duke@1:      */
duke@1:     Type checkRefType(DiagnosticPosition pos, Type t) {
duke@1:         switch (t.tag) {
duke@1:         case CLASS:
duke@1:         case ARRAY:
duke@1:         case TYPEVAR:
duke@1:         case WILDCARD:
duke@1:         case ERROR:
duke@1:             return t;
duke@1:         default:
duke@1:             return typeTagError(pos,
mcimadamore@89:                                 diags.fragment("type.req.ref"),
duke@1:                                 t);
duke@1:         }
duke@1:     }
duke@1: 
jrose@267:     /** Check that each type is a reference type, i.e. a class, interface or array type
jrose@267:      *  or a type variable.
jrose@267:      *  @param trees         Original trees, used for error reporting.
jrose@267:      *  @param types         The types to be checked.
jrose@267:      */
jrose@267:     List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
jrose@267:         List<JCExpression> tl = trees;
jrose@267:         for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
jrose@267:             l.head = checkRefType(tl.head.pos(), l.head);
jrose@267:             tl = tl.tail;
jrose@267:         }
jrose@267:         return types;
jrose@267:     }
jrose@267: 
duke@1:     /** Check that type is a null or reference type.
duke@1:      *  @param pos           Position to be used for error reporting.
duke@1:      *  @param t             The type to be checked.
duke@1:      */
duke@1:     Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
duke@1:         switch (t.tag) {
duke@1:         case CLASS:
duke@1:         case ARRAY:
duke@1:         case TYPEVAR:
duke@1:         case WILDCARD:
duke@1:         case BOT:
duke@1:         case ERROR:
duke@1:             return t;
duke@1:         default:
duke@1:             return typeTagError(pos,
mcimadamore@89:                                 diags.fragment("type.req.ref"),
duke@1:                                 t);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Check that flag set does not contain elements of two conflicting sets. s
duke@1:      *  Return true if it doesn't.
duke@1:      *  @param pos           Position to be used for error reporting.
duke@1:      *  @param flags         The set of flags to be checked.
duke@1:      *  @param set1          Conflicting flags set #1.
duke@1:      *  @param set2          Conflicting flags set #2.
duke@1:      */
duke@1:     boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
duke@1:         if ((flags & set1) != 0 && (flags & set2) != 0) {
duke@1:             log.error(pos,
duke@1:                       "illegal.combination.of.modifiers",
mcimadamore@80:                       asFlagSet(TreeInfo.firstFlag(flags & set1)),
mcimadamore@80:                       asFlagSet(TreeInfo.firstFlag(flags & set2)));
duke@1:             return false;
duke@1:         } else
duke@1:             return true;
duke@1:     }
duke@1: 
mcimadamore@537:     /** Check that the type inferred using the diamond operator does not contain
mcimadamore@537:      *  non-denotable types such as captured types or intersection types.
mcimadamore@537:      *  @param t the type inferred using the diamond operator
mcimadamore@537:      */
mcimadamore@537:     List<Type> checkDiamond(ClassType t) {
mcimadamore@537:         DiamondTypeChecker dtc = new DiamondTypeChecker();
mcimadamore@537:         ListBuffer<Type> buf = ListBuffer.lb();
mcimadamore@537:         for (Type arg : t.getTypeArguments()) {
mcimadamore@537:             if (!dtc.visit(arg, null)) {
mcimadamore@537:                 buf.append(arg);
mcimadamore@537:             }
mcimadamore@537:         }
mcimadamore@537:         return buf.toList();
mcimadamore@537:     }
mcimadamore@537: 
mcimadamore@537:     static class DiamondTypeChecker extends Types.SimpleVisitor<Boolean, Void> {
mcimadamore@537:         public Boolean visitType(Type t, Void s) {
mcimadamore@537:             return true;
mcimadamore@537:         }
mcimadamore@537:         @Override
mcimadamore@537:         public Boolean visitClassType(ClassType t, Void s) {
mcimadamore@537:             if (t.isCompound()) {
mcimadamore@537:                 return false;
mcimadamore@537:             }
mcimadamore@537:             for (Type targ : t.getTypeArguments()) {
mcimadamore@537:                 if (!visit(targ, s)) {
mcimadamore@537:                     return false;
mcimadamore@537:                 }
mcimadamore@537:             }
mcimadamore@537:             return true;
mcimadamore@537:         }
mcimadamore@537:         @Override
mcimadamore@537:         public Boolean visitCapturedType(CapturedType t, Void s) {
mcimadamore@537:             return false;
mcimadamore@537:         }
mcimadamore@537:     }
mcimadamore@537: 
mcimadamore@580:     void checkVarargMethodDecl(JCMethodDecl tree) {
mcimadamore@580:         MethodSymbol m = tree.sym;
mcimadamore@580:         //check the element type of the vararg
mcimadamore@580:         if (m.isVarArgs()) {
mcimadamore@580:             Type varargElemType = types.elemtype(tree.params.last().type);
mcimadamore@580:             if (!types.isReifiable(varargElemType)) {
mcimadamore@580:                 warnUnsafeVararg(tree.params.head.pos(), varargElemType);
mcimadamore@580:             }
mcimadamore@580:         }
mcimadamore@580:     }
mcimadamore@580: 
mcimadamore@547:     /**
mcimadamore@547:      * Check that vararg method call is sound
mcimadamore@547:      * @param pos Position to be used for error reporting.
mcimadamore@547:      * @param argtypes Actual arguments supplied to vararg method.
mcimadamore@547:      */
mcimadamore@580:     void checkVararg(DiagnosticPosition pos, List<Type> argtypes, Symbol msym, Env<AttrContext> env) {
mcimadamore@580:         Env<AttrContext> calleeLintEnv = env;
mcimadamore@580:         while (calleeLintEnv.info.lint == null)
mcimadamore@580:             calleeLintEnv = calleeLintEnv.next;
mcimadamore@580:         Lint calleeLint = calleeLintEnv.info.lint.augment(msym.attributes_field, msym.flags());
mcimadamore@547:         Type argtype = argtypes.last();
mcimadamore@580:         if (!types.isReifiable(argtype) && !calleeLint.isSuppressed(Lint.LintCategory.VARARGS)) {
mcimadamore@547:             warnUnchecked(pos,
mcimadamore@547:                               "unchecked.generic.array.creation",
mcimadamore@547:                               argtype);
mcimadamore@580:         }
mcimadamore@547:     }
mcimadamore@547: 
duke@1:     /** Check that given modifiers are legal for given symbol and
duke@1:      *  return modifiers together with any implicit modififiers for that symbol.
duke@1:      *  Warning: we can't use flags() here since this method
duke@1:      *  is called during class enter, when flags() would cause a premature
duke@1:      *  completion.
duke@1:      *  @param pos           Position to be used for error reporting.
duke@1:      *  @param flags         The set of modifiers given in a definition.
duke@1:      *  @param sym           The defined symbol.
duke@1:      */
duke@1:     long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
duke@1:         long mask;
duke@1:         long implicit = 0;
duke@1:         switch (sym.kind) {
duke@1:         case VAR:
duke@1:             if (sym.owner.kind != TYP)
duke@1:                 mask = LocalVarFlags;
duke@1:             else if ((sym.owner.flags_field & INTERFACE) != 0)
duke@1:                 mask = implicit = InterfaceVarFlags;
duke@1:             else
duke@1:                 mask = VarFlags;
duke@1:             break;
duke@1:         case MTH:
duke@1:             if (sym.name == names.init) {
duke@1:                 if ((sym.owner.flags_field & ENUM) != 0) {
duke@1:                     // enum constructors cannot be declared public or
duke@1:                     // protected and must be implicitly or explicitly
duke@1:                     // private
duke@1:                     implicit = PRIVATE;
duke@1:                     mask = PRIVATE;
duke@1:                 } else
duke@1:                     mask = ConstructorFlags;
duke@1:             }  else if ((sym.owner.flags_field & INTERFACE) != 0)
duke@1:                 mask = implicit = InterfaceMethodFlags;
duke@1:             else {
duke@1:                 mask = MethodFlags;
duke@1:             }
duke@1:             // Imply STRICTFP if owner has STRICTFP set.
duke@1:             if (((flags|implicit) & Flags.ABSTRACT) == 0)
duke@1:               implicit |= sym.owner.flags_field & STRICTFP;
duke@1:             break;
duke@1:         case TYP:
duke@1:             if (sym.isLocal()) {
duke@1:                 mask = LocalClassFlags;
jjg@113:                 if (sym.name.isEmpty()) { // Anonymous class
duke@1:                     // Anonymous classes in static methods are themselves static;
duke@1:                     // that's why we admit STATIC here.
duke@1:                     mask |= STATIC;
duke@1:                     // JLS: Anonymous classes are final.
duke@1:                     implicit |= FINAL;
duke@1:                 }
duke@1:                 if ((sym.owner.flags_field & STATIC) == 0 &&
duke@1:                     (flags & ENUM) != 0)
duke@1:                     log.error(pos, "enums.must.be.static");
duke@1:             } else if (sym.owner.kind == TYP) {
duke@1:                 mask = MemberClassFlags;
duke@1:                 if (sym.owner.owner.kind == PCK ||
duke@1:                     (sym.owner.flags_field & STATIC) != 0)
duke@1:                     mask |= STATIC;
duke@1:                 else if ((flags & ENUM) != 0)
duke@1:                     log.error(pos, "enums.must.be.static");
duke@1:                 // Nested interfaces and enums are always STATIC (Spec ???)
duke@1:                 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
duke@1:             } else {
duke@1:                 mask = ClassFlags;
duke@1:             }
duke@1:             // Interfaces are always ABSTRACT
duke@1:             if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
duke@1: 
duke@1:             if ((flags & ENUM) != 0) {
duke@1:                 // enums can't be declared abstract or final
duke@1:                 mask &= ~(ABSTRACT | FINAL);
duke@1:                 implicit |= implicitEnumFinalFlag(tree);
duke@1:             }
duke@1:             // Imply STRICTFP if owner has STRICTFP set.
duke@1:             implicit |= sym.owner.flags_field & STRICTFP;
duke@1:             break;
duke@1:         default:
duke@1:             throw new AssertionError();
duke@1:         }
duke@1:         long illegal = flags & StandardFlags & ~mask;
duke@1:         if (illegal != 0) {
duke@1:             if ((illegal & INTERFACE) != 0) {
duke@1:                 log.error(pos, "intf.not.allowed.here");
duke@1:                 mask |= INTERFACE;
duke@1:             }
duke@1:             else {
duke@1:                 log.error(pos,
mcimadamore@80:                           "mod.not.allowed.here", asFlagSet(illegal));
duke@1:             }
duke@1:         }
duke@1:         else if ((sym.kind == TYP ||
duke@1:                   // ISSUE: Disallowing abstract&private is no longer appropriate
duke@1:                   // in the presence of inner classes. Should it be deleted here?
duke@1:                   checkDisjoint(pos, flags,
duke@1:                                 ABSTRACT,
duke@1:                                 PRIVATE | STATIC))
duke@1:                  &&
duke@1:                  checkDisjoint(pos, flags,
duke@1:                                ABSTRACT | INTERFACE,
duke@1:                                FINAL | NATIVE | SYNCHRONIZED)
duke@1:                  &&
duke@1:                  checkDisjoint(pos, flags,
duke@1:                                PUBLIC,
duke@1:                                PRIVATE | PROTECTED)
duke@1:                  &&
duke@1:                  checkDisjoint(pos, flags,
duke@1:                                PRIVATE,
duke@1:                                PUBLIC | PROTECTED)
duke@1:                  &&
duke@1:                  checkDisjoint(pos, flags,
duke@1:                                FINAL,
duke@1:                                VOLATILE)
duke@1:                  &&
duke@1:                  (sym.kind == TYP ||
duke@1:                   checkDisjoint(pos, flags,
duke@1:                                 ABSTRACT | NATIVE,
duke@1:                                 STRICTFP))) {
duke@1:             // skip
duke@1:         }
duke@1:         return flags & (mask | ~StandardFlags) | implicit;
duke@1:     }
duke@1: 
duke@1: 
duke@1:     /** Determine if this enum should be implicitly final.
duke@1:      *
duke@1:      *  If the enum has no specialized enum contants, it is final.
duke@1:      *
duke@1:      *  If the enum does have specialized enum contants, it is
duke@1:      *  <i>not</i> final.
duke@1:      */
duke@1:     private long implicitEnumFinalFlag(JCTree tree) {
duke@1:         if (tree.getTag() != JCTree.CLASSDEF) return 0;
duke@1:         class SpecialTreeVisitor extends JCTree.Visitor {
duke@1:             boolean specialized;
duke@1:             SpecialTreeVisitor() {
duke@1:                 this.specialized = false;
duke@1:             };
duke@1: 
jjg@398:             @Override
duke@1:             public void visitTree(JCTree tree) { /* no-op */ }
duke@1: 
jjg@398:             @Override
duke@1:             public void visitVarDef(JCVariableDecl tree) {
duke@1:                 if ((tree.mods.flags & ENUM) != 0) {
duke@1:                     if (tree.init instanceof JCNewClass &&
duke@1:                         ((JCNewClass) tree.init).def != null) {
duke@1:                         specialized = true;
duke@1:                     }
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1: 
duke@1:         SpecialTreeVisitor sts = new SpecialTreeVisitor();
duke@1:         JCClassDecl cdef = (JCClassDecl) tree;
duke@1:         for (JCTree defs: cdef.defs) {
duke@1:             defs.accept(sts);
duke@1:             if (sts.specialized) return 0;
duke@1:         }
duke@1:         return FINAL;
duke@1:     }
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Type Validation
duke@1:  **************************************************************************/
duke@1: 
duke@1:     /** Validate a type expression. That is,
duke@1:      *  check that all type arguments of a parametric type are within
duke@1:      *  their bounds. This must be done in a second phase after type attributon
duke@1:      *  since a class might have a subclass as type parameter bound. E.g:
duke@1:      *
duke@1:      *  class B<A extends C> { ... }
duke@1:      *  class C extends B<C> { ... }
duke@1:      *
duke@1:      *  and we can't make sure that the bound is already attributed because
duke@1:      *  of possible cycles.
duke@1:      */
duke@1:     private Validator validator = new Validator();
duke@1: 
duke@1:     /** Visitor method: Validate a type expression, if it is not null, catching
duke@1:      *  and reporting any completion failures.
duke@1:      */
mcimadamore@122:     void validate(JCTree tree, Env<AttrContext> env) {
duke@1:         try {
mcimadamore@122:             if (tree != null) {
mcimadamore@122:                 validator.env = env;
mcimadamore@122:                 tree.accept(validator);
mcimadamore@122:                 checkRaw(tree, env);
mcimadamore@122:             }
duke@1:         } catch (CompletionFailure ex) {
duke@1:             completionError(tree.pos(), ex);
duke@1:         }
duke@1:     }
mcimadamore@122:     //where
mcimadamore@122:     void checkRaw(JCTree tree, Env<AttrContext> env) {
mcimadamore@122:         if (lint.isEnabled(Lint.LintCategory.RAW) &&
mcimadamore@122:             tree.type.tag == CLASS &&
mcimadamore@564:             !TreeInfo.isDiamond(tree) &&
mcimadamore@122:             !env.enclClass.name.isEmpty() &&  //anonymous or intersection
mcimadamore@122:             tree.type.isRaw()) {
mcimadamore@122:             log.warning(tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
mcimadamore@122:         }
mcimadamore@122:     }
duke@1: 
duke@1:     /** Visitor method: Validate a list of type expressions.
duke@1:      */
mcimadamore@122:     void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
duke@1:         for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
mcimadamore@122:             validate(l.head, env);
duke@1:     }
duke@1: 
duke@1:     /** A visitor class for type validation.
duke@1:      */
duke@1:     class Validator extends JCTree.Visitor {
duke@1: 
jjg@398:         @Override
duke@1:         public void visitTypeArray(JCArrayTypeTree tree) {
mcimadamore@122:             validate(tree.elemtype, env);
duke@1:         }
duke@1: 
jjg@398:         @Override
duke@1:         public void visitTypeApply(JCTypeApply tree) {
duke@1:             if (tree.type.tag == CLASS) {
mcimadamore@158:                 List<Type> formals = tree.type.tsym.type.allparams();
mcimadamore@158:                 List<Type> actuals = tree.type.allparams();
duke@1:                 List<JCExpression> args = tree.arguments;
mcimadamore@158:                 List<Type> forms = tree.type.tsym.type.getTypeArguments();
mcimadamore@561:                 ListBuffer<Type> tvars_buf = new ListBuffer<Type>();
duke@1: 
duke@1:                 // For matching pairs of actual argument types `a' and
duke@1:                 // formal type parameters with declared bound `b' ...
duke@1:                 while (args.nonEmpty() && forms.nonEmpty()) {
mcimadamore@122:                     validate(args.head, env);
duke@1: 
duke@1:                     // exact type arguments needs to know their
duke@1:                     // bounds (for upper and lower bound
duke@1:                     // calculations).  So we create new TypeVars with
duke@1:                     // bounds substed with actuals.
duke@1:                     tvars_buf.append(types.substBound(((TypeVar)forms.head),
duke@1:                                                       formals,
mcimadamore@78:                                                       actuals));
duke@1: 
duke@1:                     args = args.tail;
duke@1:                     forms = forms.tail;
duke@1:                 }
duke@1: 
duke@1:                 args = tree.arguments;
mcimadamore@154:                 List<Type> tvars_cap = types.substBounds(formals,
mcimadamore@154:                                           formals,
mcimadamore@158:                                           types.capture(tree.type).allparams());
mcimadamore@154:                 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
mcimadamore@154:                     // Let the actual arguments know their bound
mcimadamore@154:                     args.head.type.withTypeVar((TypeVar)tvars_cap.head);
mcimadamore@154:                     args = args.tail;
mcimadamore@154:                     tvars_cap = tvars_cap.tail;
mcimadamore@154:                 }
mcimadamore@154: 
mcimadamore@154:                 args = tree.arguments;
mcimadamore@561:                 List<Type> tvars = tvars_buf.toList();
mcimadamore@154: 
duke@1:                 while (args.nonEmpty() && tvars.nonEmpty()) {
mcimadamore@561:                     Type actual = types.subst(args.head.type,
mcimadamore@561:                         tree.type.tsym.type.getTypeArguments(),
mcimadamore@561:                         tvars_buf.toList());
mcimadamore@154:                     checkExtends(args.head.pos(),
mcimadamore@561:                                  actual,
mcimadamore@561:                                  (TypeVar)tvars.head);
duke@1:                     args = args.tail;
duke@1:                     tvars = tvars.tail;
duke@1:                 }
duke@1: 
mcimadamore@154:                 checkCapture(tree);
mcimadamore@536: 
duke@1:                 // Check that this type is either fully parameterized, or
duke@1:                 // not parameterized at all.
duke@1:                 if (tree.type.getEnclosingType().isRaw())
duke@1:                     log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
duke@1:                 if (tree.clazz.getTag() == JCTree.SELECT)
duke@1:                     visitSelectInternal((JCFieldAccess)tree.clazz);
duke@1:             }
duke@1:         }
duke@1: 
jjg@398:         @Override
duke@1:         public void visitTypeParameter(JCTypeParameter tree) {
mcimadamore@122:             validate(tree.bounds, env);
duke@1:             checkClassBounds(tree.pos(), tree.type);
duke@1:         }
duke@1: 
duke@1:         @Override
duke@1:         public void visitWildcard(JCWildcard tree) {
duke@1:             if (tree.inner != null)
mcimadamore@122:                 validate(tree.inner, env);
duke@1:         }
duke@1: 
jjg@398:         @Override
duke@1:         public void visitSelect(JCFieldAccess tree) {
duke@1:             if (tree.type.tag == CLASS) {
duke@1:                 visitSelectInternal(tree);
duke@1: 
duke@1:                 // Check that this type is either fully parameterized, or
duke@1:                 // not parameterized at all.
duke@1:                 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
duke@1:                     log.error(tree.pos(), "improperly.formed.type.param.missing");
duke@1:             }
duke@1:         }
duke@1:         public void visitSelectInternal(JCFieldAccess tree) {
mcimadamore@122:             if (tree.type.tsym.isStatic() &&
duke@1:                 tree.selected.type.isParameterized()) {
duke@1:                 // The enclosing type is not a class, so we are
duke@1:                 // looking at a static member type.  However, the
duke@1:                 // qualifying expression is parameterized.
duke@1:                 log.error(tree.pos(), "cant.select.static.class.from.param.type");
duke@1:             } else {
duke@1:                 // otherwise validate the rest of the expression
mcimadamore@122:                 tree.selected.accept(this);
duke@1:             }
duke@1:         }
duke@1: 
jjg@398:         @Override
jjg@308:         public void visitAnnotatedType(JCAnnotatedType tree) {
jjg@308:             tree.underlyingType.accept(this);
jjg@308:         }
jjg@308: 
duke@1:         /** Default visitor method: do nothing.
duke@1:          */
jjg@398:         @Override
duke@1:         public void visitTree(JCTree tree) {
duke@1:         }
mcimadamore@122: 
mcimadamore@122:         Env<AttrContext> env;
duke@1:     }
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Exception checking
duke@1:  **************************************************************************/
duke@1: 
duke@1:     /* The following methods treat classes as sets that contain
duke@1:      * the class itself and all their subclasses
duke@1:      */
duke@1: 
duke@1:     /** Is given type a subtype of some of the types in given list?
duke@1:      */
duke@1:     boolean subset(Type t, List<Type> ts) {
duke@1:         for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
duke@1:             if (types.isSubtype(t, l.head)) return true;
duke@1:         return false;
duke@1:     }
duke@1: 
duke@1:     /** Is given type a subtype or supertype of
duke@1:      *  some of the types in given list?
duke@1:      */
duke@1:     boolean intersects(Type t, List<Type> ts) {
duke@1:         for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
duke@1:             if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
duke@1:         return false;
duke@1:     }
duke@1: 
duke@1:     /** Add type set to given type list, unless it is a subclass of some class
duke@1:      *  in the list.
duke@1:      */
duke@1:     List<Type> incl(Type t, List<Type> ts) {
duke@1:         return subset(t, ts) ? ts : excl(t, ts).prepend(t);
duke@1:     }
duke@1: 
duke@1:     /** Remove type set from type set list.
duke@1:      */
duke@1:     List<Type> excl(Type t, List<Type> ts) {
duke@1:         if (ts.isEmpty()) {
duke@1:             return ts;
duke@1:         } else {
duke@1:             List<Type> ts1 = excl(t, ts.tail);
duke@1:             if (types.isSubtype(ts.head, t)) return ts1;
duke@1:             else if (ts1 == ts.tail) return ts;
duke@1:             else return ts1.prepend(ts.head);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Form the union of two type set lists.
duke@1:      */
duke@1:     List<Type> union(List<Type> ts1, List<Type> ts2) {
duke@1:         List<Type> ts = ts1;
duke@1:         for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
duke@1:             ts = incl(l.head, ts);
duke@1:         return ts;
duke@1:     }
duke@1: 
duke@1:     /** Form the difference of two type lists.
duke@1:      */
duke@1:     List<Type> diff(List<Type> ts1, List<Type> ts2) {
duke@1:         List<Type> ts = ts1;
duke@1:         for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
duke@1:             ts = excl(l.head, ts);
duke@1:         return ts;
duke@1:     }
duke@1: 
duke@1:     /** Form the intersection of two type lists.
duke@1:      */
duke@1:     public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
duke@1:         List<Type> ts = List.nil();
duke@1:         for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
duke@1:             if (subset(l.head, ts2)) ts = incl(l.head, ts);
duke@1:         for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
duke@1:             if (subset(l.head, ts1)) ts = incl(l.head, ts);
duke@1:         return ts;
duke@1:     }
duke@1: 
duke@1:     /** Is exc an exception symbol that need not be declared?
duke@1:      */
duke@1:     boolean isUnchecked(ClassSymbol exc) {
duke@1:         return
duke@1:             exc.kind == ERR ||
duke@1:             exc.isSubClass(syms.errorType.tsym, types) ||
duke@1:             exc.isSubClass(syms.runtimeExceptionType.tsym, types);
duke@1:     }
duke@1: 
duke@1:     /** Is exc an exception type that need not be declared?
duke@1:      */
duke@1:     boolean isUnchecked(Type exc) {
duke@1:         return
duke@1:             (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
duke@1:             (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
duke@1:             exc.tag == BOT;
duke@1:     }
duke@1: 
duke@1:     /** Same, but handling completion failures.
duke@1:      */
duke@1:     boolean isUnchecked(DiagnosticPosition pos, Type exc) {
duke@1:         try {
duke@1:             return isUnchecked(exc);
duke@1:         } catch (CompletionFailure ex) {
duke@1:             completionError(pos, ex);
duke@1:             return true;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Is exc handled by given exception list?
duke@1:      */
duke@1:     boolean isHandled(Type exc, List<Type> handled) {
duke@1:         return isUnchecked(exc) || subset(exc, handled);
duke@1:     }
duke@1: 
duke@1:     /** Return all exceptions in thrown list that are not in handled list.
duke@1:      *  @param thrown     The list of thrown exceptions.
duke@1:      *  @param handled    The list of handled exceptions.
duke@1:      */
mcimadamore@362:     List<Type> unhandled(List<Type> thrown, List<Type> handled) {
duke@1:         List<Type> unhandled = List.nil();
duke@1:         for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
duke@1:             if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
duke@1:         return unhandled;
duke@1:     }
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Overriding/Implementation checking
duke@1:  **************************************************************************/
duke@1: 
duke@1:     /** The level of access protection given by a flag set,
duke@1:      *  where PRIVATE is highest and PUBLIC is lowest.
duke@1:      */
duke@1:     static int protection(long flags) {
duke@1:         switch ((short)(flags & AccessFlags)) {
duke@1:         case PRIVATE: return 3;
duke@1:         case PROTECTED: return 1;
duke@1:         default:
duke@1:         case PUBLIC: return 0;
duke@1:         case 0: return 2;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** A customized "cannot override" error message.
duke@1:      *  @param m      The overriding method.
duke@1:      *  @param other  The overridden method.
duke@1:      *  @return       An internationalized string.
duke@1:      */
mcimadamore@89:     Object cannotOverride(MethodSymbol m, MethodSymbol other) {
duke@1:         String key;
duke@1:         if ((other.owner.flags() & INTERFACE) == 0)
duke@1:             key = "cant.override";
duke@1:         else if ((m.owner.flags() & INTERFACE) == 0)
duke@1:             key = "cant.implement";
duke@1:         else
duke@1:             key = "clashes.with";
mcimadamore@89:         return diags.fragment(key, m, m.location(), other, other.location());
duke@1:     }
duke@1: 
duke@1:     /** A customized "override" warning message.
duke@1:      *  @param m      The overriding method.
duke@1:      *  @param other  The overridden method.
duke@1:      *  @return       An internationalized string.
duke@1:      */
mcimadamore@89:     Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
duke@1:         String key;
duke@1:         if ((other.owner.flags() & INTERFACE) == 0)
duke@1:             key = "unchecked.override";
duke@1:         else if ((m.owner.flags() & INTERFACE) == 0)
duke@1:             key = "unchecked.implement";
duke@1:         else
duke@1:             key = "unchecked.clash.with";
mcimadamore@89:         return diags.fragment(key, m, m.location(), other, other.location());
duke@1:     }
duke@1: 
duke@1:     /** A customized "override" warning message.
duke@1:      *  @param m      The overriding method.
duke@1:      *  @param other  The overridden method.
duke@1:      *  @return       An internationalized string.
duke@1:      */
mcimadamore@89:     Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
duke@1:         String key;
duke@1:         if ((other.owner.flags() & INTERFACE) == 0)
duke@1:             key = "varargs.override";
duke@1:         else  if ((m.owner.flags() & INTERFACE) == 0)
duke@1:             key = "varargs.implement";
duke@1:         else
duke@1:             key = "varargs.clash.with";
mcimadamore@89:         return diags.fragment(key, m, m.location(), other, other.location());
duke@1:     }
duke@1: 
duke@1:     /** Check that this method conforms with overridden method 'other'.
duke@1:      *  where `origin' is the class where checking started.
duke@1:      *  Complications:
duke@1:      *  (1) Do not check overriding of synthetic methods
duke@1:      *      (reason: they might be final).
duke@1:      *      todo: check whether this is still necessary.
duke@1:      *  (2) Admit the case where an interface proxy throws fewer exceptions
duke@1:      *      than the method it implements. Augment the proxy methods with the
duke@1:      *      undeclared exceptions in this case.
duke@1:      *  (3) When generics are enabled, admit the case where an interface proxy
duke@1:      *      has a result type
duke@1:      *      extended by the result type of the method it implements.
duke@1:      *      Change the proxies result type to the smaller type in this case.
duke@1:      *
duke@1:      *  @param tree         The tree from which positions
duke@1:      *                      are extracted for errors.
duke@1:      *  @param m            The overriding method.
duke@1:      *  @param other        The overridden method.
duke@1:      *  @param origin       The class of which the overriding method
duke@1:      *                      is a member.
duke@1:      */
duke@1:     void checkOverride(JCTree tree,
duke@1:                        MethodSymbol m,
duke@1:                        MethodSymbol other,
duke@1:                        ClassSymbol origin) {
duke@1:         // Don't check overriding of synthetic methods or by bridge methods.
duke@1:         if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
duke@1:             return;
duke@1:         }
duke@1: 
duke@1:         // Error if static method overrides instance method (JLS 8.4.6.2).
duke@1:         if ((m.flags() & STATIC) != 0 &&
duke@1:                    (other.flags() & STATIC) == 0) {
duke@1:             log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
duke@1:                       cannotOverride(m, other));
duke@1:             return;
duke@1:         }
duke@1: 
duke@1:         // Error if instance method overrides static or final
duke@1:         // method (JLS 8.4.6.1).
duke@1:         if ((other.flags() & FINAL) != 0 ||
duke@1:                  (m.flags() & STATIC) == 0 &&
duke@1:                  (other.flags() & STATIC) != 0) {
duke@1:             log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
duke@1:                       cannotOverride(m, other),
mcimadamore@80:                       asFlagSet(other.flags() & (FINAL | STATIC)));
duke@1:             return;
duke@1:         }
duke@1: 
duke@1:         if ((m.owner.flags() & ANNOTATION) != 0) {
duke@1:             // handled in validateAnnotationMethod
duke@1:             return;
duke@1:         }
duke@1: 
duke@1:         // Error if overriding method has weaker access (JLS 8.4.6.3).
duke@1:         if ((origin.flags() & INTERFACE) == 0 &&
duke@1:                  protection(m.flags()) > protection(other.flags())) {
duke@1:             log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
duke@1:                       cannotOverride(m, other),
mcimadamore@80:                       other.flags() == 0 ?
mcimadamore@80:                           Flag.PACKAGE :
mcimadamore@80:                           asFlagSet(other.flags() & AccessFlags));
duke@1:             return;
duke@1:         }
duke@1: 
duke@1:         Type mt = types.memberType(origin.type, m);
duke@1:         Type ot = types.memberType(origin.type, other);
duke@1:         // Error if overriding result type is different
duke@1:         // (or, in the case of generics mode, not a subtype) of
duke@1:         // overridden result type. We have to rename any type parameters
duke@1:         // before comparing types.
duke@1:         List<Type> mtvars = mt.getTypeArguments();
duke@1:         List<Type> otvars = ot.getTypeArguments();
duke@1:         Type mtres = mt.getReturnType();
duke@1:         Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
duke@1: 
duke@1:         overrideWarner.warned = false;
duke@1:         boolean resultTypesOK =
tbell@202:             types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
duke@1:         if (!resultTypesOK) {
jjg@398:             if (!allowCovariantReturns &&
duke@1:                 m.owner != origin &&
duke@1:                 m.owner.isSubClass(other.owner, types)) {
duke@1:                 // allow limited interoperability with covariant returns
duke@1:             } else {
mcimadamore@362:                 log.error(TreeInfo.diagnosticPositionFor(m, tree),
mcimadamore@362:                           "override.incompatible.ret",
mcimadamore@362:                           cannotOverride(m, other),
duke@1:                           mtres, otres);
duke@1:                 return;
duke@1:             }
duke@1:         } else if (overrideWarner.warned) {
duke@1:             warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
mcimadamore@362:                     "override.unchecked.ret",
mcimadamore@362:                     uncheckedOverrides(m, other),
mcimadamore@362:                     mtres, otres);
duke@1:         }
duke@1: 
duke@1:         // Error if overriding method throws an exception not reported
duke@1:         // by overridden method.
duke@1:         List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
mcimadamore@362:         List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
mcimadamore@362:         List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
mcimadamore@362:         if (unhandledErased.nonEmpty()) {
duke@1:             log.error(TreeInfo.diagnosticPositionFor(m, tree),
duke@1:                       "override.meth.doesnt.throw",
duke@1:                       cannotOverride(m, other),
mcimadamore@362:                       unhandledUnerased.head);
mcimadamore@362:             return;
mcimadamore@362:         }
mcimadamore@362:         else if (unhandledUnerased.nonEmpty()) {
mcimadamore@362:             warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
mcimadamore@362:                           "override.unchecked.thrown",
mcimadamore@362:                          cannotOverride(m, other),
mcimadamore@362:                          unhandledUnerased.head);
duke@1:             return;
duke@1:         }
duke@1: 
duke@1:         // Optional warning if varargs don't agree
duke@1:         if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
duke@1:             && lint.isEnabled(Lint.LintCategory.OVERRIDES)) {
duke@1:             log.warning(TreeInfo.diagnosticPositionFor(m, tree),
duke@1:                         ((m.flags() & Flags.VARARGS) != 0)
duke@1:                         ? "override.varargs.missing"
duke@1:                         : "override.varargs.extra",
duke@1:                         varargsOverrides(m, other));
duke@1:         }
duke@1: 
duke@1:         // Warn if instance method overrides bridge method (compiler spec ??)
duke@1:         if ((other.flags() & BRIDGE) != 0) {
duke@1:             log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
duke@1:                         uncheckedOverrides(m, other));
duke@1:         }
duke@1: 
duke@1:         // Warn if a deprecated method overridden by a non-deprecated one.
duke@1:         if ((other.flags() & DEPRECATED) != 0
duke@1:             && (m.flags() & DEPRECATED) == 0
duke@1:             && m.outermostClass() != other.outermostClass()
duke@1:             && !isDeprecatedOverrideIgnorable(other, origin)) {
duke@1:             warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
duke@1:         }
duke@1:     }
duke@1:     // where
duke@1:         private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
duke@1:             // If the method, m, is defined in an interface, then ignore the issue if the method
duke@1:             // is only inherited via a supertype and also implemented in the supertype,
duke@1:             // because in that case, we will rediscover the issue when examining the method
duke@1:             // in the supertype.
duke@1:             // If the method, m, is not defined in an interface, then the only time we need to
duke@1:             // address the issue is when the method is the supertype implemementation: any other
duke@1:             // case, we will have dealt with when examining the supertype classes
duke@1:             ClassSymbol mc = m.enclClass();
duke@1:             Type st = types.supertype(origin.type);
duke@1:             if (st.tag != CLASS)
duke@1:                 return true;
duke@1:             MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
duke@1: 
duke@1:             if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
duke@1:                 List<Type> intfs = types.interfaces(origin.type);
duke@1:                 return (intfs.contains(mc.type) ? false : (stimpl != null));
duke@1:             }
duke@1:             else
duke@1:                 return (stimpl != m);
duke@1:         }
duke@1: 
duke@1: 
duke@1:     // used to check if there were any unchecked conversions
duke@1:     Warner overrideWarner = new Warner();
duke@1: 
duke@1:     /** Check that a class does not inherit two concrete methods
duke@1:      *  with the same signature.
duke@1:      *  @param pos          Position to be used for error reporting.
duke@1:      *  @param site         The class type to be checked.
duke@1:      */
duke@1:     public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
duke@1:         Type sup = types.supertype(site);
duke@1:         if (sup.tag != CLASS) return;
duke@1: 
duke@1:         for (Type t1 = sup;
duke@1:              t1.tsym.type.isParameterized();
duke@1:              t1 = types.supertype(t1)) {
duke@1:             for (Scope.Entry e1 = t1.tsym.members().elems;
duke@1:                  e1 != null;
duke@1:                  e1 = e1.sibling) {
duke@1:                 Symbol s1 = e1.sym;
duke@1:                 if (s1.kind != MTH ||
duke@1:                     (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
duke@1:                     !s1.isInheritedIn(site.tsym, types) ||
duke@1:                     ((MethodSymbol)s1).implementation(site.tsym,
duke@1:                                                       types,
duke@1:                                                       true) != s1)
duke@1:                     continue;
duke@1:                 Type st1 = types.memberType(t1, s1);
duke@1:                 int s1ArgsLength = st1.getParameterTypes().length();
duke@1:                 if (st1 == s1.type) continue;
duke@1: 
duke@1:                 for (Type t2 = sup;
duke@1:                      t2.tag == CLASS;
duke@1:                      t2 = types.supertype(t2)) {
mcimadamore@24:                     for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
duke@1:                          e2.scope != null;
duke@1:                          e2 = e2.next()) {
duke@1:                         Symbol s2 = e2.sym;
duke@1:                         if (s2 == s1 ||
duke@1:                             s2.kind != MTH ||
duke@1:                             (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
duke@1:                             s2.type.getParameterTypes().length() != s1ArgsLength ||
duke@1:                             !s2.isInheritedIn(site.tsym, types) ||
duke@1:                             ((MethodSymbol)s2).implementation(site.tsym,
duke@1:                                                               types,
duke@1:                                                               true) != s2)
duke@1:                             continue;
duke@1:                         Type st2 = types.memberType(t2, s2);
duke@1:                         if (types.overrideEquivalent(st1, st2))
duke@1:                             log.error(pos, "concrete.inheritance.conflict",
duke@1:                                       s1, t1, s2, t2, sup);
duke@1:                     }
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Check that classes (or interfaces) do not each define an abstract
duke@1:      *  method with same name and arguments but incompatible return types.
duke@1:      *  @param pos          Position to be used for error reporting.
duke@1:      *  @param t1           The first argument type.
duke@1:      *  @param t2           The second argument type.
duke@1:      */
duke@1:     public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
duke@1:                                             Type t1,
duke@1:                                             Type t2) {
duke@1:         return checkCompatibleAbstracts(pos, t1, t2,
duke@1:                                         types.makeCompoundType(t1, t2));
duke@1:     }
duke@1: 
duke@1:     public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
duke@1:                                             Type t1,
duke@1:                                             Type t2,
duke@1:                                             Type site) {
duke@1:         Symbol sym = firstIncompatibility(t1, t2, site);
duke@1:         if (sym != null) {
duke@1:             log.error(pos, "types.incompatible.diff.ret",
duke@1:                       t1, t2, sym.name +
duke@1:                       "(" + types.memberType(t2, sym).getParameterTypes() + ")");
duke@1:             return false;
duke@1:         }
duke@1:         return true;
duke@1:     }
duke@1: 
duke@1:     /** Return the first method which is defined with same args
duke@1:      *  but different return types in two given interfaces, or null if none
duke@1:      *  exists.
duke@1:      *  @param t1     The first type.
duke@1:      *  @param t2     The second type.
duke@1:      *  @param site   The most derived type.
duke@1:      *  @returns symbol from t2 that conflicts with one in t1.
duke@1:      */
duke@1:     private Symbol firstIncompatibility(Type t1, Type t2, Type site) {
duke@1:         Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
duke@1:         closure(t1, interfaces1);
duke@1:         Map<TypeSymbol,Type> interfaces2;
duke@1:         if (t1 == t2)
duke@1:             interfaces2 = interfaces1;
duke@1:         else
duke@1:             closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
duke@1: 
duke@1:         for (Type t3 : interfaces1.values()) {
duke@1:             for (Type t4 : interfaces2.values()) {
duke@1:                 Symbol s = firstDirectIncompatibility(t3, t4, site);
duke@1:                 if (s != null) return s;
duke@1:             }
duke@1:         }
duke@1:         return null;
duke@1:     }
duke@1: 
duke@1:     /** Compute all the supertypes of t, indexed by type symbol. */
duke@1:     private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
duke@1:         if (t.tag != CLASS) return;
duke@1:         if (typeMap.put(t.tsym, t) == null) {
duke@1:             closure(types.supertype(t), typeMap);
duke@1:             for (Type i : types.interfaces(t))
duke@1:                 closure(i, typeMap);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
duke@1:     private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
duke@1:         if (t.tag != CLASS) return;
duke@1:         if (typesSkip.get(t.tsym) != null) return;
duke@1:         if (typeMap.put(t.tsym, t) == null) {
duke@1:             closure(types.supertype(t), typesSkip, typeMap);
duke@1:             for (Type i : types.interfaces(t))
duke@1:                 closure(i, typesSkip, typeMap);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Return the first method in t2 that conflicts with a method from t1. */
duke@1:     private Symbol firstDirectIncompatibility(Type t1, Type t2, Type site) {
duke@1:         for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
duke@1:             Symbol s1 = e1.sym;
duke@1:             Type st1 = null;
duke@1:             if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
duke@1:             Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
duke@1:             if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
duke@1:             for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
duke@1:                 Symbol s2 = e2.sym;
duke@1:                 if (s1 == s2) continue;
duke@1:                 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
duke@1:                 if (st1 == null) st1 = types.memberType(t1, s1);
duke@1:                 Type st2 = types.memberType(t2, s2);
duke@1:                 if (types.overrideEquivalent(st1, st2)) {
duke@1:                     List<Type> tvars1 = st1.getTypeArguments();
duke@1:                     List<Type> tvars2 = st2.getTypeArguments();
duke@1:                     Type rt1 = st1.getReturnType();
duke@1:                     Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
duke@1:                     boolean compat =
duke@1:                         types.isSameType(rt1, rt2) ||
duke@1:                         rt1.tag >= CLASS && rt2.tag >= CLASS &&
duke@1:                         (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
mcimadamore@59:                          types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
mcimadamore@59:                          checkCommonOverriderIn(s1,s2,site);
duke@1:                     if (!compat) return s2;
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1:         return null;
duke@1:     }
mcimadamore@59:     //WHERE
mcimadamore@59:     boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
mcimadamore@59:         Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
mcimadamore@59:         Type st1 = types.memberType(site, s1);
mcimadamore@59:         Type st2 = types.memberType(site, s2);
mcimadamore@59:         closure(site, supertypes);
mcimadamore@59:         for (Type t : supertypes.values()) {
mcimadamore@59:             for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
mcimadamore@59:                 Symbol s3 = e.sym;
mcimadamore@59:                 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
mcimadamore@59:                 Type st3 = types.memberType(site,s3);
mcimadamore@59:                 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
mcimadamore@59:                     if (s3.owner == site.tsym) {
mcimadamore@59:                         return true;
mcimadamore@59:                     }
mcimadamore@59:                     List<Type> tvars1 = st1.getTypeArguments();
mcimadamore@59:                     List<Type> tvars2 = st2.getTypeArguments();
mcimadamore@59:                     List<Type> tvars3 = st3.getTypeArguments();
mcimadamore@59:                     Type rt1 = st1.getReturnType();
mcimadamore@59:                     Type rt2 = st2.getReturnType();
mcimadamore@59:                     Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
mcimadamore@59:                     Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
mcimadamore@59:                     boolean compat =
mcimadamore@59:                         rt13.tag >= CLASS && rt23.tag >= CLASS &&
mcimadamore@59:                         (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
mcimadamore@59:                          types.covariantReturnType(rt23, rt2, Warner.noWarnings));
mcimadamore@59:                     if (compat)
mcimadamore@59:                         return true;
mcimadamore@59:                 }
mcimadamore@59:             }
mcimadamore@59:         }
mcimadamore@59:         return false;
mcimadamore@59:     }
duke@1: 
duke@1:     /** Check that a given method conforms with any method it overrides.
duke@1:      *  @param tree         The tree from which positions are extracted
duke@1:      *                      for errors.
duke@1:      *  @param m            The overriding method.
duke@1:      */
duke@1:     void checkOverride(JCTree tree, MethodSymbol m) {
duke@1:         ClassSymbol origin = (ClassSymbol)m.owner;
duke@1:         if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
duke@1:             if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
duke@1:                 log.error(tree.pos(), "enum.no.finalize");
duke@1:                 return;
duke@1:             }
duke@1:         for (Type t = types.supertype(origin.type); t.tag == CLASS;
duke@1:              t = types.supertype(t)) {
duke@1:             TypeSymbol c = t.tsym;
duke@1:             Scope.Entry e = c.members().lookup(m.name);
duke@1:             while (e.scope != null) {
duke@1:                 if (m.overrides(e.sym, origin, types, false))
duke@1:                     checkOverride(tree, m, (MethodSymbol)e.sym, origin);
mcimadamore@252:                 else if (e.sym.kind == MTH &&
mcimadamore@252:                         e.sym.isInheritedIn(origin, types) &&
mcimadamore@252:                         (e.sym.flags() & SYNTHETIC) == 0 &&
mcimadamore@252:                         !m.isConstructor()) {
mcimadamore@24:                     Type er1 = m.erasure(types);
mcimadamore@24:                     Type er2 = e.sym.erasure(types);
mcimadamore@252:                     if (types.isSameTypes(er1.getParameterTypes(),
mcimadamore@252:                             er2.getParameterTypes())) {
mcimadamore@24:                             log.error(TreeInfo.diagnosticPositionFor(m, tree),
mcimadamore@24:                                     "name.clash.same.erasure.no.override",
mcimadamore@24:                                     m, m.location(),
mcimadamore@24:                                     e.sym, e.sym.location());
mcimadamore@24:                     }
mcimadamore@24:                 }
duke@1:                 e = e.next();
duke@1:             }
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Check that all abstract members of given class have definitions.
duke@1:      *  @param pos          Position to be used for error reporting.
duke@1:      *  @param c            The class.
duke@1:      */
duke@1:     void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
duke@1:         try {
duke@1:             MethodSymbol undef = firstUndef(c, c);
duke@1:             if (undef != null) {
duke@1:                 if ((c.flags() & ENUM) != 0 &&
duke@1:                     types.supertype(c.type).tsym == syms.enumSym &&
duke@1:                     (c.flags() & FINAL) == 0) {
duke@1:                     // add the ABSTRACT flag to an enum
duke@1:                     c.flags_field |= ABSTRACT;
duke@1:                 } else {
duke@1:                     MethodSymbol undef1 =
duke@1:                         new MethodSymbol(undef.flags(), undef.name,
duke@1:                                          types.memberType(c.type, undef), undef.owner);
duke@1:                     log.error(pos, "does.not.override.abstract",
duke@1:                               c, undef1, undef1.location());
duke@1:                 }
duke@1:             }
duke@1:         } catch (CompletionFailure ex) {
duke@1:             completionError(pos, ex);
duke@1:         }
duke@1:     }
duke@1: //where
duke@1:         /** Return first abstract member of class `c' that is not defined
duke@1:          *  in `impl', null if there is none.
duke@1:          */
duke@1:         private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
duke@1:             MethodSymbol undef = null;
duke@1:             // Do not bother to search in classes that are not abstract,
duke@1:             // since they cannot have abstract members.
duke@1:             if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
duke@1:                 Scope s = c.members();
duke@1:                 for (Scope.Entry e = s.elems;
duke@1:                      undef == null && e != null;
duke@1:                      e = e.sibling) {
duke@1:                     if (e.sym.kind == MTH &&
duke@1:                         (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
duke@1:                         MethodSymbol absmeth = (MethodSymbol)e.sym;
duke@1:                         MethodSymbol implmeth = absmeth.implementation(impl, types, true);
duke@1:                         if (implmeth == null || implmeth == absmeth)
duke@1:                             undef = absmeth;
duke@1:                     }
duke@1:                 }
duke@1:                 if (undef == null) {
duke@1:                     Type st = types.supertype(c.type);
duke@1:                     if (st.tag == CLASS)
duke@1:                         undef = firstUndef(impl, (ClassSymbol)st.tsym);
duke@1:                 }
duke@1:                 for (List<Type> l = types.interfaces(c.type);
duke@1:                      undef == null && l.nonEmpty();
duke@1:                      l = l.tail) {
duke@1:                     undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
duke@1:                 }
duke@1:             }
duke@1:             return undef;
duke@1:         }
duke@1: 
duke@1:     /** Check for cyclic references. Issue an error if the
duke@1:      *  symbol of the type referred to has a LOCKED flag set.
duke@1:      *
duke@1:      *  @param pos      Position to be used for error reporting.
duke@1:      *  @param t        The type referred to.
duke@1:      */
duke@1:     void checkNonCyclic(DiagnosticPosition pos, Type t) {
duke@1:         checkNonCyclicInternal(pos, t);
duke@1:     }
duke@1: 
duke@1: 
duke@1:     void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
mcimadamore@236:         checkNonCyclic1(pos, t, List.<TypeVar>nil());
duke@1:     }
duke@1: 
mcimadamore@236:     private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
duke@1:         final TypeVar tv;
mcimadamore@42:         if  (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
mcimadamore@42:             return;
duke@1:         if (seen.contains(t)) {
duke@1:             tv = (TypeVar)t;
jjg@110:             tv.bound = types.createErrorType(t);
duke@1:             log.error(pos, "cyclic.inheritance", t);
duke@1:         } else if (t.tag == TYPEVAR) {
duke@1:             tv = (TypeVar)t;
mcimadamore@236:             seen = seen.prepend(tv);
duke@1:             for (Type b : types.getBounds(tv))
duke@1:                 checkNonCyclic1(pos, b, seen);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Check for cyclic references. Issue an error if the
duke@1:      *  symbol of the type referred to has a LOCKED flag set.
duke@1:      *
duke@1:      *  @param pos      Position to be used for error reporting.
duke@1:      *  @param t        The type referred to.
duke@1:      *  @returns        True if the check completed on all attributed classes
duke@1:      */
duke@1:     private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
duke@1:         boolean complete = true; // was the check complete?
duke@1:         //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
duke@1:         Symbol c = t.tsym;
duke@1:         if ((c.flags_field & ACYCLIC) != 0) return true;
duke@1: 
duke@1:         if ((c.flags_field & LOCKED) != 0) {
duke@1:             noteCyclic(pos, (ClassSymbol)c);
duke@1:         } else if (!c.type.isErroneous()) {
duke@1:             try {
duke@1:                 c.flags_field |= LOCKED;
duke@1:                 if (c.type.tag == CLASS) {
duke@1:                     ClassType clazz = (ClassType)c.type;
duke@1:                     if (clazz.interfaces_field != null)
duke@1:                         for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
duke@1:                             complete &= checkNonCyclicInternal(pos, l.head);
duke@1:                     if (clazz.supertype_field != null) {
duke@1:                         Type st = clazz.supertype_field;
duke@1:                         if (st != null && st.tag == CLASS)
duke@1:                             complete &= checkNonCyclicInternal(pos, st);
duke@1:                     }
duke@1:                     if (c.owner.kind == TYP)
duke@1:                         complete &= checkNonCyclicInternal(pos, c.owner.type);
duke@1:                 }
duke@1:             } finally {
duke@1:                 c.flags_field &= ~LOCKED;
duke@1:             }
duke@1:         }
duke@1:         if (complete)
duke@1:             complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
duke@1:         if (complete) c.flags_field |= ACYCLIC;
duke@1:         return complete;
duke@1:     }
duke@1: 
duke@1:     /** Note that we found an inheritance cycle. */
duke@1:     private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
duke@1:         log.error(pos, "cyclic.inheritance", c);
duke@1:         for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
jjg@110:             l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
duke@1:         Type st = types.supertype(c.type);
duke@1:         if (st.tag == CLASS)
jjg@110:             ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
jjg@110:         c.type = types.createErrorType(c, c.type);
duke@1:         c.flags_field |= ACYCLIC;
duke@1:     }
duke@1: 
duke@1:     /** Check that all methods which implement some
duke@1:      *  method conform to the method they implement.
duke@1:      *  @param tree         The class definition whose members are checked.
duke@1:      */
duke@1:     void checkImplementations(JCClassDecl tree) {
duke@1:         checkImplementations(tree, tree.sym);
duke@1:     }
duke@1: //where
duke@1:         /** Check that all methods which implement some
duke@1:          *  method in `ic' conform to the method they implement.
duke@1:          */
duke@1:         void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
duke@1:             ClassSymbol origin = tree.sym;
duke@1:             for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
duke@1:                 ClassSymbol lc = (ClassSymbol)l.head.tsym;
duke@1:                 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
duke@1:                     for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
duke@1:                         if (e.sym.kind == MTH &&
duke@1:                             (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
duke@1:                             MethodSymbol absmeth = (MethodSymbol)e.sym;
duke@1:                             MethodSymbol implmeth = absmeth.implementation(origin, types, false);
duke@1:                             if (implmeth != null && implmeth != absmeth &&
duke@1:                                 (implmeth.owner.flags() & INTERFACE) ==
duke@1:                                 (origin.flags() & INTERFACE)) {
duke@1:                                 // don't check if implmeth is in a class, yet
duke@1:                                 // origin is an interface. This case arises only
duke@1:                                 // if implmeth is declared in Object. The reason is
duke@1:                                 // that interfaces really don't inherit from
duke@1:                                 // Object it's just that the compiler represents
duke@1:                                 // things that way.
duke@1:                                 checkOverride(tree, implmeth, absmeth, origin);
duke@1:                             }
duke@1:                         }
duke@1:                     }
duke@1:                 }
duke@1:             }
duke@1:         }
duke@1: 
duke@1:     /** Check that all abstract methods implemented by a class are
duke@1:      *  mutually compatible.
duke@1:      *  @param pos          Position to be used for error reporting.
duke@1:      *  @param c            The class whose interfaces are checked.
duke@1:      */
duke@1:     void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
duke@1:         List<Type> supertypes = types.interfaces(c);
duke@1:         Type supertype = types.supertype(c);
duke@1:         if (supertype.tag == CLASS &&
duke@1:             (supertype.tsym.flags() & ABSTRACT) != 0)
duke@1:             supertypes = supertypes.prepend(supertype);
duke@1:         for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
duke@1:             if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
duke@1:                 !checkCompatibleAbstracts(pos, l.head, l.head, c))
duke@1:                 return;
duke@1:             for (List<Type> m = supertypes; m != l; m = m.tail)
duke@1:                 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
duke@1:                     return;
duke@1:         }
duke@1:         checkCompatibleConcretes(pos, c);
duke@1:     }
duke@1: 
mcimadamore@359:     void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
mcimadamore@359:         for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
mcimadamore@359:             for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
mcimadamore@359:                 // VM allows methods and variables with differing types
mcimadamore@359:                 if (sym.kind == e.sym.kind &&
mcimadamore@359:                     types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
mcimadamore@359:                     sym != e.sym &&
mcimadamore@359:                     (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
mcimadamore@359:                     (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
mcimadamore@359:                     syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
mcimadamore@359:                     return;
mcimadamore@359:                 }
mcimadamore@359:             }
mcimadamore@359:         }
mcimadamore@359:     }
mcimadamore@359: 
mcimadamore@359:     /** Report a conflict between a user symbol and a synthetic symbol.
mcimadamore@359:      */
mcimadamore@359:     private void syntheticError(DiagnosticPosition pos, Symbol sym) {
mcimadamore@359:         if (!sym.type.isErroneous()) {
mcimadamore@359:             if (warnOnSyntheticConflicts) {
mcimadamore@359:                 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
mcimadamore@359:             }
mcimadamore@359:             else {
mcimadamore@359:                 log.error(pos, "synthetic.name.conflict", sym, sym.location());
mcimadamore@359:             }
mcimadamore@359:         }
mcimadamore@359:     }
mcimadamore@359: 
duke@1:     /** Check that class c does not implement directly or indirectly
duke@1:      *  the same parameterized interface with two different argument lists.
duke@1:      *  @param pos          Position to be used for error reporting.
duke@1:      *  @param type         The type whose interfaces are checked.
duke@1:      */
duke@1:     void checkClassBounds(DiagnosticPosition pos, Type type) {
duke@1:         checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
duke@1:     }
duke@1: //where
duke@1:         /** Enter all interfaces of type `type' into the hash table `seensofar'
duke@1:          *  with their class symbol as key and their type as value. Make
duke@1:          *  sure no class is entered with two different types.
duke@1:          */
duke@1:         void checkClassBounds(DiagnosticPosition pos,
duke@1:                               Map<TypeSymbol,Type> seensofar,
duke@1:                               Type type) {
duke@1:             if (type.isErroneous()) return;
duke@1:             for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
duke@1:                 Type it = l.head;
duke@1:                 Type oldit = seensofar.put(it.tsym, it);
duke@1:                 if (oldit != null) {
duke@1:                     List<Type> oldparams = oldit.allparams();
duke@1:                     List<Type> newparams = it.allparams();
duke@1:                     if (!types.containsTypeEquivalent(oldparams, newparams))
duke@1:                         log.error(pos, "cant.inherit.diff.arg",
duke@1:                                   it.tsym, Type.toString(oldparams),
duke@1:                                   Type.toString(newparams));
duke@1:                 }
duke@1:                 checkClassBounds(pos, seensofar, it);
duke@1:             }
duke@1:             Type st = types.supertype(type);
duke@1:             if (st != null) checkClassBounds(pos, seensofar, st);
duke@1:         }
duke@1: 
duke@1:     /** Enter interface into into set.
duke@1:      *  If it existed already, issue a "repeated interface" error.
duke@1:      */
duke@1:     void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
duke@1:         if (its.contains(it))
duke@1:             log.error(pos, "repeated.interface");
duke@1:         else {
duke@1:             its.add(it);
duke@1:         }
duke@1:     }
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Check annotations
duke@1:  **************************************************************************/
duke@1: 
duke@1:     /** Annotation types are restricted to primitives, String, an
duke@1:      *  enum, an annotation, Class, Class<?>, Class<? extends
duke@1:      *  Anything>, arrays of the preceding.
duke@1:      */
duke@1:     void validateAnnotationType(JCTree restype) {
duke@1:         // restype may be null if an error occurred, so don't bother validating it
duke@1:         if (restype != null) {
duke@1:             validateAnnotationType(restype.pos(), restype.type);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     void validateAnnotationType(DiagnosticPosition pos, Type type) {
duke@1:         if (type.isPrimitive()) return;
duke@1:         if (types.isSameType(type, syms.stringType)) return;
duke@1:         if ((type.tsym.flags() & Flags.ENUM) != 0) return;
duke@1:         if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
duke@1:         if (types.lowerBound(type).tsym == syms.classType.tsym) return;
duke@1:         if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
duke@1:             validateAnnotationType(pos, types.elemtype(type));
duke@1:             return;
duke@1:         }
duke@1:         log.error(pos, "invalid.annotation.member.type");
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * "It is also a compile-time error if any method declared in an
duke@1:      * annotation type has a signature that is override-equivalent to
duke@1:      * that of any public or protected method declared in class Object
duke@1:      * or in the interface annotation.Annotation."
duke@1:      *
duke@1:      * @jls3 9.6 Annotation Types
duke@1:      */
duke@1:     void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
duke@1:         for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
duke@1:             Scope s = sup.tsym.members();
duke@1:             for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
duke@1:                 if (e.sym.kind == MTH &&
duke@1:                     (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
duke@1:                     types.overrideEquivalent(m.type, e.sym.type))
duke@1:                     log.error(pos, "intf.annotation.member.clash", e.sym, sup);
duke@1:             }
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Check the annotations of a symbol.
duke@1:      */
duke@1:     public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
duke@1:         if (skipAnnotations) return;
duke@1:         for (JCAnnotation a : annotations)
duke@1:             validateAnnotation(a, s);
duke@1:     }
duke@1: 
jjg@308:     /** Check the type annotations
jjg@308:      */
jjg@308:     public void validateTypeAnnotations(List<JCTypeAnnotation> annotations, boolean isTypeParameter) {
jjg@308:         if (skipAnnotations) return;
jjg@308:         for (JCTypeAnnotation a : annotations)
jjg@308:             validateTypeAnnotation(a, isTypeParameter);
jjg@308:     }
jjg@308: 
duke@1:     /** Check an annotation of a symbol.
duke@1:      */
duke@1:     public void validateAnnotation(JCAnnotation a, Symbol s) {
duke@1:         validateAnnotation(a);
duke@1: 
duke@1:         if (!annotationApplicable(a, s))
duke@1:             log.error(a.pos(), "annotation.type.not.applicable");
duke@1: 
duke@1:         if (a.annotationType.type.tsym == syms.overrideType.tsym) {
duke@1:             if (!isOverrider(s))
duke@1:                 log.error(a.pos(), "method.does.not.override.superclass");
duke@1:         }
duke@1:     }
duke@1: 
jjg@308:     public void validateTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
jjg@308:         if (a.type == null)
jjg@308:             throw new AssertionError("annotation tree hasn't been attributed yet: " + a);
jjg@308:         validateAnnotation(a);
jjg@308: 
jjg@308:         if (!isTypeAnnotation(a, isTypeParameter))
jjg@308:             log.error(a.pos(), "annotation.type.not.applicable");
jjg@308:     }
jjg@308: 
duke@1:     /** Is s a method symbol that overrides a method in a superclass? */
duke@1:     boolean isOverrider(Symbol s) {
duke@1:         if (s.kind != MTH || s.isStatic())
duke@1:             return false;
duke@1:         MethodSymbol m = (MethodSymbol)s;
duke@1:         TypeSymbol owner = (TypeSymbol)m.owner;
duke@1:         for (Type sup : types.closure(owner.type)) {
duke@1:             if (sup == owner.type)
duke@1:                 continue; // skip "this"
duke@1:             Scope scope = sup.tsym.members();
duke@1:             for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
duke@1:                 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
duke@1:                     return true;
duke@1:             }
duke@1:         }
duke@1:         return false;
duke@1:     }
duke@1: 
jjg@308:     /** Is the annotation applicable to type annotations */
jjg@308:     boolean isTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
jjg@308:         Attribute.Compound atTarget =
jjg@308:             a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
jjg@308:         if (atTarget == null) return true;
jjg@308:         Attribute atValue = atTarget.member(names.value);
jjg@308:         if (!(atValue instanceof Attribute.Array)) return true; // error recovery
jjg@308:         Attribute.Array arr = (Attribute.Array) atValue;
jjg@308:         for (Attribute app : arr.values) {
jjg@308:             if (!(app instanceof Attribute.Enum)) return true; // recovery
jjg@308:             Attribute.Enum e = (Attribute.Enum) app;
jjg@308:             if (!isTypeParameter && e.value.name == names.TYPE_USE)
jjg@308:                 return true;
jjg@308:             else if (isTypeParameter && e.value.name == names.TYPE_PARAMETER)
jjg@308:                 return true;
jjg@308:         }
jjg@308:         return false;
jjg@308:     }
jjg@308: 
duke@1:     /** Is the annotation applicable to the symbol? */
duke@1:     boolean annotationApplicable(JCAnnotation a, Symbol s) {
duke@1:         Attribute.Compound atTarget =
duke@1:             a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
duke@1:         if (atTarget == null) return true;
duke@1:         Attribute atValue = atTarget.member(names.value);
duke@1:         if (!(atValue instanceof Attribute.Array)) return true; // error recovery
duke@1:         Attribute.Array arr = (Attribute.Array) atValue;
duke@1:         for (Attribute app : arr.values) {
duke@1:             if (!(app instanceof Attribute.Enum)) return true; // recovery
duke@1:             Attribute.Enum e = (Attribute.Enum) app;
duke@1:             if (e.value.name == names.TYPE)
duke@1:                 { if (s.kind == TYP) return true; }
duke@1:             else if (e.value.name == names.FIELD)
duke@1:                 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
duke@1:             else if (e.value.name == names.METHOD)
duke@1:                 { if (s.kind == MTH && !s.isConstructor()) return true; }
duke@1:             else if (e.value.name == names.PARAMETER)
duke@1:                 { if (s.kind == VAR &&
duke@1:                       s.owner.kind == MTH &&
duke@1:                       (s.flags() & PARAMETER) != 0)
duke@1:                     return true;
duke@1:                 }
duke@1:             else if (e.value.name == names.CONSTRUCTOR)
duke@1:                 { if (s.kind == MTH && s.isConstructor()) return true; }
duke@1:             else if (e.value.name == names.LOCAL_VARIABLE)
duke@1:                 { if (s.kind == VAR && s.owner.kind == MTH &&
duke@1:                       (s.flags() & PARAMETER) == 0)
duke@1:                     return true;
duke@1:                 }
duke@1:             else if (e.value.name == names.ANNOTATION_TYPE)
duke@1:                 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
duke@1:                     return true;
duke@1:                 }
duke@1:             else if (e.value.name == names.PACKAGE)
duke@1:                 { if (s.kind == PCK) return true; }
jjg@308:             else if (e.value.name == names.TYPE_USE)
jjg@308:                 { if (s.kind == TYP ||
jjg@308:                       s.kind == VAR ||
jjg@308:                       (s.kind == MTH && !s.isConstructor() &&
jjg@308:                        s.type.getReturnType().tag != VOID))
jjg@308:                     return true;
jjg@308:                 }
duke@1:             else
duke@1:                 return true; // recovery
duke@1:         }
duke@1:         return false;
duke@1:     }
duke@1: 
duke@1:     /** Check an annotation value.
duke@1:      */
duke@1:     public void validateAnnotation(JCAnnotation a) {
duke@1:         if (a.type.isErroneous()) return;
duke@1: 
duke@1:         // collect an inventory of the members
duke@1:         Set<MethodSymbol> members = new HashSet<MethodSymbol>();
duke@1:         for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
duke@1:              e != null;
duke@1:              e = e.sibling)
duke@1:             if (e.sym.kind == MTH)
duke@1:                 members.add((MethodSymbol) e.sym);
duke@1: 
duke@1:         // count them off as they're annotated
duke@1:         for (JCTree arg : a.args) {
duke@1:             if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
duke@1:             JCAssign assign = (JCAssign) arg;
duke@1:             Symbol m = TreeInfo.symbol(assign.lhs);
duke@1:             if (m == null || m.type.isErroneous()) continue;
duke@1:             if (!members.remove(m))
jjg@479:                 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
duke@1:                           m.name, a.type);
duke@1:             if (assign.rhs.getTag() == ANNOTATION)
duke@1:                 validateAnnotation((JCAnnotation)assign.rhs);
duke@1:         }
duke@1: 
duke@1:         // all the remaining ones better have default values
duke@1:         for (MethodSymbol m : members)
duke@1:             if (m.defaultValue == null && !m.type.isErroneous())
duke@1:                 log.error(a.pos(), "annotation.missing.default.value",
duke@1:                           a.type, m.name);
duke@1: 
duke@1:         // special case: java.lang.annotation.Target must not have
duke@1:         // repeated values in its value member
duke@1:         if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
duke@1:             a.args.tail == null)
duke@1:             return;
duke@1: 
duke@1:         if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
duke@1:         JCAssign assign = (JCAssign) a.args.head;
duke@1:         Symbol m = TreeInfo.symbol(assign.lhs);
duke@1:         if (m.name != names.value) return;
duke@1:         JCTree rhs = assign.rhs;
duke@1:         if (rhs.getTag() != JCTree.NEWARRAY) return;
duke@1:         JCNewArray na = (JCNewArray) rhs;
duke@1:         Set<Symbol> targets = new HashSet<Symbol>();
duke@1:         for (JCTree elem : na.elems) {
duke@1:             if (!targets.add(TreeInfo.symbol(elem))) {
duke@1:                 log.error(elem.pos(), "repeated.annotation.target");
duke@1:             }
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
duke@1:         if (allowAnnotations &&
duke@1:             lint.isEnabled(Lint.LintCategory.DEP_ANN) &&
duke@1:             (s.flags() & DEPRECATED) != 0 &&
duke@1:             !syms.deprecatedType.isErroneous() &&
duke@1:             s.attribute(syms.deprecatedType.tsym) == null) {
duke@1:             log.warning(pos, "missing.deprecated.annotation");
duke@1:         }
duke@1:     }
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Check for recursive annotation elements.
duke@1:  **************************************************************************/
duke@1: 
duke@1:     /** Check for cycles in the graph of annotation elements.
duke@1:      */
duke@1:     void checkNonCyclicElements(JCClassDecl tree) {
duke@1:         if ((tree.sym.flags_field & ANNOTATION) == 0) return;
duke@1:         assert (tree.sym.flags_field & LOCKED) == 0;
duke@1:         try {
duke@1:             tree.sym.flags_field |= LOCKED;
duke@1:             for (JCTree def : tree.defs) {
duke@1:                 if (def.getTag() != JCTree.METHODDEF) continue;
duke@1:                 JCMethodDecl meth = (JCMethodDecl)def;
duke@1:                 checkAnnotationResType(meth.pos(), meth.restype.type);
duke@1:             }
duke@1:         } finally {
duke@1:             tree.sym.flags_field &= ~LOCKED;
duke@1:             tree.sym.flags_field |= ACYCLIC_ANN;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
duke@1:         if ((tsym.flags_field & ACYCLIC_ANN) != 0)
duke@1:             return;
duke@1:         if ((tsym.flags_field & LOCKED) != 0) {
duke@1:             log.error(pos, "cyclic.annotation.element");
duke@1:             return;
duke@1:         }
duke@1:         try {
duke@1:             tsym.flags_field |= LOCKED;
duke@1:             for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
duke@1:                 Symbol s = e.sym;
duke@1:                 if (s.kind != Kinds.MTH)
duke@1:                     continue;
duke@1:                 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
duke@1:             }
duke@1:         } finally {
duke@1:             tsym.flags_field &= ~LOCKED;
duke@1:             tsym.flags_field |= ACYCLIC_ANN;
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     void checkAnnotationResType(DiagnosticPosition pos, Type type) {
duke@1:         switch (type.tag) {
duke@1:         case TypeTags.CLASS:
duke@1:             if ((type.tsym.flags() & ANNOTATION) != 0)
duke@1:                 checkNonCyclicElementsInternal(pos, type.tsym);
duke@1:             break;
duke@1:         case TypeTags.ARRAY:
duke@1:             checkAnnotationResType(pos, types.elemtype(type));
duke@1:             break;
duke@1:         default:
duke@1:             break; // int etc
duke@1:         }
duke@1:     }
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Check for cycles in the constructor call graph.
duke@1:  **************************************************************************/
duke@1: 
duke@1:     /** Check for cycles in the graph of constructors calling other
duke@1:      *  constructors.
duke@1:      */
duke@1:     void checkCyclicConstructors(JCClassDecl tree) {
duke@1:         Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
duke@1: 
duke@1:         // enter each constructor this-call into the map
duke@1:         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
duke@1:             JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
duke@1:             if (app == null) continue;
duke@1:             JCMethodDecl meth = (JCMethodDecl) l.head;
duke@1:             if (TreeInfo.name(app.meth) == names._this) {
duke@1:                 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
duke@1:             } else {
duke@1:                 meth.sym.flags_field |= ACYCLIC;
duke@1:             }
duke@1:         }
duke@1: 
duke@1:         // Check for cycles in the map
duke@1:         Symbol[] ctors = new Symbol[0];
duke@1:         ctors = callMap.keySet().toArray(ctors);
duke@1:         for (Symbol caller : ctors) {
duke@1:             checkCyclicConstructor(tree, caller, callMap);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Look in the map to see if the given constructor is part of a
duke@1:      *  call cycle.
duke@1:      */
duke@1:     private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
duke@1:                                         Map<Symbol,Symbol> callMap) {
duke@1:         if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
duke@1:             if ((ctor.flags_field & LOCKED) != 0) {
duke@1:                 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
duke@1:                           "recursive.ctor.invocation");
duke@1:             } else {
duke@1:                 ctor.flags_field |= LOCKED;
duke@1:                 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
duke@1:                 ctor.flags_field &= ~LOCKED;
duke@1:             }
duke@1:             ctor.flags_field |= ACYCLIC;
duke@1:         }
duke@1:     }
duke@1: 
duke@1: /* *************************************************************************
duke@1:  * Miscellaneous
duke@1:  **************************************************************************/
duke@1: 
duke@1:     /**
duke@1:      * Return the opcode of the operator but emit an error if it is an
duke@1:      * error.
duke@1:      * @param pos        position for error reporting.
duke@1:      * @param operator   an operator
duke@1:      * @param tag        a tree tag
duke@1:      * @param left       type of left hand side
duke@1:      * @param right      type of right hand side
duke@1:      */
duke@1:     int checkOperator(DiagnosticPosition pos,
duke@1:                        OperatorSymbol operator,
duke@1:                        int tag,
duke@1:                        Type left,
duke@1:                        Type right) {
duke@1:         if (operator.opcode == ByteCodes.error) {
duke@1:             log.error(pos,
duke@1:                       "operator.cant.be.applied",
duke@1:                       treeinfo.operatorName(tag),
mcimadamore@80:                       List.of(left, right));
duke@1:         }
duke@1:         return operator.opcode;
duke@1:     }
duke@1: 
duke@1: 
duke@1:     /**
duke@1:      *  Check for division by integer constant zero
duke@1:      *  @param pos           Position for error reporting.
duke@1:      *  @param operator      The operator for the expression
duke@1:      *  @param operand       The right hand operand for the expression
duke@1:      */
duke@1:     void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
duke@1:         if (operand.constValue() != null
duke@1:             && lint.isEnabled(Lint.LintCategory.DIVZERO)
duke@1:             && operand.tag <= LONG
duke@1:             && ((Number) (operand.constValue())).longValue() == 0) {
duke@1:             int opc = ((OperatorSymbol)operator).opcode;
duke@1:             if (opc == ByteCodes.idiv || opc == ByteCodes.imod
duke@1:                 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
duke@1:                 log.warning(pos, "div.zero");
duke@1:             }
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * Check for empty statements after if
duke@1:      */
duke@1:     void checkEmptyIf(JCIf tree) {
duke@1:         if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(Lint.LintCategory.EMPTY))
duke@1:             log.warning(tree.thenpart.pos(), "empty.if");
duke@1:     }
duke@1: 
duke@1:     /** Check that symbol is unique in given scope.
duke@1:      *  @param pos           Position for error reporting.
duke@1:      *  @param sym           The symbol.
duke@1:      *  @param s             The scope.
duke@1:      */
duke@1:     boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
duke@1:         if (sym.type.isErroneous())
duke@1:             return true;
duke@1:         if (sym.owner.name == names.any) return false;
duke@1:         for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
duke@1:             if (sym != e.sym &&
duke@1:                 sym.kind == e.sym.kind &&
duke@1:                 sym.name != names.error &&
mcimadamore@252:                 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
duke@1:                 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
duke@1:                     varargsDuplicateError(pos, sym, e.sym);
mcimadamore@252:                 else if (sym.kind == MTH && !types.overrideEquivalent(sym.type, e.sym.type))
mcimadamore@252:                     duplicateErasureError(pos, sym, e.sym);
duke@1:                 else
duke@1:                     duplicateError(pos, e.sym);
duke@1:                 return false;
duke@1:             }
duke@1:         }
duke@1:         return true;
duke@1:     }
mcimadamore@252:     //where
mcimadamore@252:     /** Report duplicate declaration error.
mcimadamore@252:      */
mcimadamore@252:     void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
mcimadamore@252:         if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
mcimadamore@252:             log.error(pos, "name.clash.same.erasure", sym1, sym2);
mcimadamore@252:         }
mcimadamore@252:     }
duke@1: 
duke@1:     /** Check that single-type import is not already imported or top-level defined,
duke@1:      *  but make an exception for two single-type imports which denote the same type.
duke@1:      *  @param pos           Position for error reporting.
duke@1:      *  @param sym           The symbol.
duke@1:      *  @param s             The scope
duke@1:      */
duke@1:     boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
duke@1:         return checkUniqueImport(pos, sym, s, false);
duke@1:     }
duke@1: 
duke@1:     /** Check that static single-type import is not already imported or top-level defined,
duke@1:      *  but make an exception for two single-type imports which denote the same type.
duke@1:      *  @param pos           Position for error reporting.
duke@1:      *  @param sym           The symbol.
duke@1:      *  @param s             The scope
duke@1:      *  @param staticImport  Whether or not this was a static import
duke@1:      */
duke@1:     boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
duke@1:         return checkUniqueImport(pos, sym, s, true);
duke@1:     }
duke@1: 
duke@1:     /** Check that single-type import is not already imported or top-level defined,
duke@1:      *  but make an exception for two single-type imports which denote the same type.
duke@1:      *  @param pos           Position for error reporting.
duke@1:      *  @param sym           The symbol.
duke@1:      *  @param s             The scope.
duke@1:      *  @param staticImport  Whether or not this was a static import
duke@1:      */
duke@1:     private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
duke@1:         for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
duke@1:             // is encountered class entered via a class declaration?
duke@1:             boolean isClassDecl = e.scope == s;
duke@1:             if ((isClassDecl || sym != e.sym) &&
duke@1:                 sym.kind == e.sym.kind &&
duke@1:                 sym.name != names.error) {
duke@1:                 if (!e.sym.type.isErroneous()) {
duke@1:                     String what = e.sym.toString();
duke@1:                     if (!isClassDecl) {
duke@1:                         if (staticImport)
duke@1:                             log.error(pos, "already.defined.static.single.import", what);
duke@1:                         else
duke@1:                             log.error(pos, "already.defined.single.import", what);
duke@1:                     }
duke@1:                     else if (sym != e.sym)
duke@1:                         log.error(pos, "already.defined.this.unit", what);
duke@1:                 }
duke@1:                 return false;
duke@1:             }
duke@1:         }
duke@1:         return true;
duke@1:     }
duke@1: 
duke@1:     /** Check that a qualified name is in canonical form (for import decls).
duke@1:      */
duke@1:     public void checkCanonical(JCTree tree) {
duke@1:         if (!isCanonical(tree))
duke@1:             log.error(tree.pos(), "import.requires.canonical",
duke@1:                       TreeInfo.symbol(tree));
duke@1:     }
duke@1:         // where
duke@1:         private boolean isCanonical(JCTree tree) {
duke@1:             while (tree.getTag() == JCTree.SELECT) {
duke@1:                 JCFieldAccess s = (JCFieldAccess) tree;
duke@1:                 if (s.sym.owner != TreeInfo.symbol(s.selected))
duke@1:                     return false;
duke@1:                 tree = s.selected;
duke@1:             }
duke@1:             return true;
duke@1:         }
duke@1: 
duke@1:     private class ConversionWarner extends Warner {
duke@1:         final String key;
duke@1:         final Type found;
duke@1:         final Type expected;
duke@1:         public ConversionWarner(DiagnosticPosition pos, String key, Type found, Type expected) {
duke@1:             super(pos);
duke@1:             this.key = key;
duke@1:             this.found = found;
duke@1:             this.expected = expected;
duke@1:         }
duke@1: 
jjg@398:         @Override
duke@1:         public void warnUnchecked() {
duke@1:             boolean warned = this.warned;
duke@1:             super.warnUnchecked();
duke@1:             if (warned) return; // suppress redundant diagnostics
mcimadamore@89:             Object problem = diags.fragment(key);
duke@1:             Check.this.warnUnchecked(pos(), "prob.found.req", problem, found, expected);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
duke@1:         return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
duke@1:     }
duke@1: 
duke@1:     public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
duke@1:         return new ConversionWarner(pos, "unchecked.assign", found, expected);
duke@1:     }
duke@1: }