1 /*
   2  * Copyright 1999-2009 Sun Microsystems, Inc.  All Rights Reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Sun designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Sun in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  22  * CA 95054 USA or visit www.sun.com if you need additional information or
  23  * have any questions.
  24  */
  25 
  26 package com.sun.tools.javac.comp;
  27 
  28 import java.util.*;
  29 import java.util.Set;
  30 import javax.lang.model.element.ElementKind;
  31 import javax.tools.JavaFileObject;
  32 
  33 import com.sun.tools.javac.code.*;
  34 import com.sun.tools.javac.jvm.*;
  35 import com.sun.tools.javac.tree.*;
  36 import com.sun.tools.javac.util.*;
  37 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  38 import com.sun.tools.javac.util.List;
  39 
  40 import com.sun.tools.javac.jvm.Target;
  41 import com.sun.tools.javac.code.Symbol.*;
  42 import com.sun.tools.javac.tree.JCTree.*;
  43 import com.sun.tools.javac.code.Type.*;
  44 
  45 import com.sun.source.tree.IdentifierTree;
  46 import com.sun.source.tree.MemberSelectTree;
  47 import com.sun.source.tree.TreeVisitor;
  48 import com.sun.source.util.SimpleTreeVisitor;
  49 
  50 import static com.sun.tools.javac.code.Flags.*;
  51 import static com.sun.tools.javac.code.Kinds.*;
  52 import static com.sun.tools.javac.code.TypeTags.*;
  53 
  54 /** This is the main context-dependent analysis phase in GJC. It
  55  *  encompasses name resolution, type checking and constant folding as
  56  *  subtasks. Some subtasks involve auxiliary classes.
  57  *  @see Check
  58  *  @see Resolve
  59  *  @see ConstFold
  60  *  @see Infer
  61  *
  62  *  <p><b>This is NOT part of any API supported by Sun Microsystems.  If
  63  *  you write code that depends on this, you do so at your own risk.
  64  *  This code and its internal interfaces are subject to change or
  65  *  deletion without notice.</b>
  66  */
  67 public class Attr extends JCTree.Visitor {
  68     protected static final Context.Key<Attr> attrKey =
  69         new Context.Key<Attr>();
  70 
  71     final Names names;
  72     final Log log;
  73     final Symtab syms;
  74     final Resolve rs;
  75     final Check chk;
  76     final MemberEnter memberEnter;
  77     final TreeMaker make;
  78     final ConstFold cfolder;
  79     final Enter enter;
  80     final Target target;
  81     final Types types;
  82     final JCDiagnostic.Factory diags;
  83     final Annotate annotate;
  84 
  85     public static Attr instance(Context context) {
  86         Attr instance = context.get(attrKey);
  87         if (instance == null)
  88             instance = new Attr(context);
  89         return instance;
  90     }
  91 
  92     protected Attr(Context context) {
  93         context.put(attrKey, this);
  94 
  95         names = Names.instance(context);
  96         log = Log.instance(context);
  97         syms = Symtab.instance(context);
  98         rs = Resolve.instance(context);
  99         chk = Check.instance(context);
 100         memberEnter = MemberEnter.instance(context);
 101         make = TreeMaker.instance(context);
 102         enter = Enter.instance(context);
 103         cfolder = ConstFold.instance(context);
 104         target = Target.instance(context);
 105         types = Types.instance(context);
 106         diags = JCDiagnostic.Factory.instance(context);
 107         annotate = Annotate.instance(context);
 108 
 109         Options options = Options.instance(context);
 110 
 111         Source source = Source.instance(context);
 112         allowGenerics = source.allowGenerics();
 113         allowVarargs = source.allowVarargs();
 114         allowEnums = source.allowEnums();
 115         allowBoxing = source.allowBoxing();
 116         allowCovariantReturns = source.allowCovariantReturns();
 117         allowAnonOuterThis = source.allowAnonOuterThis();
 118         relax = (options.get("-retrofit") != null ||
 119                  options.get("-relax") != null);
 120         useBeforeDeclarationWarning = options.get("useBeforeDeclarationWarning") != null;
 121         allowInvokedynamic = options.get("invokedynamic") != null;
 122         enableSunApiLintControl = options.get("enableSunApiLintControl") != null;
 123     }
 124 
 125     /** Switch: relax some constraints for retrofit mode.
 126      */
 127     boolean relax;
 128 
 129     /** Switch: support generics?
 130      */
 131     boolean allowGenerics;
 132 
 133     /** Switch: allow variable-arity methods.
 134      */
 135     boolean allowVarargs;
 136 
 137     /** Switch: support enums?
 138      */
 139     boolean allowEnums;
 140 
 141     /** Switch: support boxing and unboxing?
 142      */
 143     boolean allowBoxing;
 144 
 145     /** Switch: support covariant result types?
 146      */
 147     boolean allowCovariantReturns;
 148 
 149     /** Switch: allow references to surrounding object from anonymous
 150      * objects during constructor call?
 151      */
 152     boolean allowAnonOuterThis;
 153 
 154     /** Switch: allow invokedynamic syntax
 155      */
 156     boolean allowInvokedynamic;
 157 
 158     /**
 159      * Switch: warn about use of variable before declaration?
 160      * RFE: 6425594
 161      */
 162     boolean useBeforeDeclarationWarning;
 163 
 164     /**
 165      * Switch: allow lint infrastructure to control Sun proprietary
 166      * API warnings.
 167      */
 168     boolean enableSunApiLintControl;
 169 
 170     /** Check kind and type of given tree against protokind and prototype.
 171      *  If check succeeds, store type in tree and return it.
 172      *  If check fails, store errType in tree and return it.
 173      *  No checks are performed if the prototype is a method type.
 174      *  It is not necessary in this case since we know that kind and type
 175      *  are correct.
 176      *
 177      *  @param tree     The tree whose kind and type is checked
 178      *  @param owntype  The computed type of the tree
 179      *  @param ownkind  The computed kind of the tree
 180      *  @param pkind    The expected kind (or: protokind) of the tree
 181      *  @param pt       The expected type (or: prototype) of the tree
 182      */
 183     Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
 184         if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
 185             if ((ownkind & ~pkind) == 0) {
 186                 owntype = chk.checkType(tree.pos(), owntype, pt);
 187             } else {
 188                 log.error(tree.pos(), "unexpected.type",
 189                           kindNames(pkind),
 190                           kindName(ownkind));
 191                 owntype = types.createErrorType(owntype);
 192             }
 193         }
 194         tree.type = owntype;
 195         return owntype;
 196     }
 197 
 198     Type checkReturn(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
 199         if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
 200             if ((ownkind & ~pkind) == 0) {
 201                 owntype = chk.checkReturnType(tree.pos(), owntype, pt);
 202             } else {
 203                 log.error(tree.pos(), "unexpected.type",
 204                           kindNames(pkind),
 205                           kindName(ownkind));
 206                 owntype = types.createErrorType(owntype);
 207             }
 208         }
 209         tree.type = owntype;
 210         return owntype;
 211     }
 212 
 213     /** Is given blank final variable assignable, i.e. in a scope where it
 214      *  may be assigned to even though it is final?
 215      *  @param v      The blank final variable.
 216      *  @param env    The current environment.
 217      */
 218     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 219         Symbol owner = env.info.scope.owner;
 220            // owner refers to the innermost variable, method or
 221            // initializer block declaration at this point.
 222         return
 223             v.owner == owner
 224             ||
 225             ((owner.name == names.init ||    // i.e. we are in a constructor
 226               owner.kind == VAR ||           // i.e. we are in a variable initializer
 227               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 228              &&
 229              v.owner == owner.owner
 230              &&
 231              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 232     }
 233 
 234     /** Check that variable can be assigned to.
 235      *  @param pos    The current source code position.
 236      *  @param v      The assigned varaible
 237      *  @param base   If the variable is referred to in a Select, the part
 238      *                to the left of the `.', null otherwise.
 239      *  @param env    The current environment.
 240      */
 241     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 242         if ((v.flags() & FINAL) != 0 &&
 243             ((v.flags() & HASINIT) != 0
 244              ||
 245              !((base == null ||
 246                (base.getTag() == JCTree.IDENT && TreeInfo.name(base) == names._this)) &&
 247                isAssignableAsBlankFinal(v, env)))) {
 248             log.error(pos, "cant.assign.val.to.final.var", v);
 249         }
 250     }
 251 
 252     /** Does tree represent a static reference to an identifier?
 253      *  It is assumed that tree is either a SELECT or an IDENT.
 254      *  We have to weed out selects from non-type names here.
 255      *  @param tree    The candidate tree.
 256      */
 257     boolean isStaticReference(JCTree tree) {
 258         if (tree.getTag() == JCTree.SELECT) {
 259             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 260             if (lsym == null || lsym.kind != TYP) {
 261                 return false;
 262             }
 263         }
 264         return true;
 265     }
 266 
 267     /** Is this symbol a type?
 268      */
 269     static boolean isType(Symbol sym) {
 270         return sym != null && sym.kind == TYP;
 271     }
 272 
 273     /** The current `this' symbol.
 274      *  @param env    The current environment.
 275      */
 276     Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
 277         return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
 278     }
 279 
 280     /** Attribute a parsed identifier.
 281      * @param tree Parsed identifier name
 282      * @param topLevel The toplevel to use
 283      */
 284     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 285         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 286         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 287                                            syms.errSymbol.name,
 288                                            null, null, null, null);
 289         localEnv.enclClass.sym = syms.errSymbol;
 290         return tree.accept(identAttributer, localEnv);
 291     }
 292     // where
 293         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 294         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 295             @Override
 296             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 297                 Symbol site = visit(node.getExpression(), env);
 298                 if (site.kind == ERR)
 299                     return site;
 300                 Name name = (Name)node.getIdentifier();
 301                 if (site.kind == PCK) {
 302                     env.toplevel.packge = (PackageSymbol)site;
 303                     return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
 304                 } else {
 305                     env.enclClass.sym = (ClassSymbol)site;
 306                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 307                 }
 308             }
 309 
 310             @Override
 311             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 312                 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
 313             }
 314         }
 315 
 316     public Type coerce(Type etype, Type ttype) {
 317         return cfolder.coerce(etype, ttype);
 318     }
 319 
 320     public Type attribType(JCTree node, TypeSymbol sym) {
 321         Env<AttrContext> env = enter.typeEnvs.get(sym);
 322         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 323         return attribTree(node, localEnv, Kinds.TYP, Type.noType);
 324     }
 325 
 326     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 327         breakTree = tree;
 328         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 329         try {
 330             attribExpr(expr, env);
 331         } catch (BreakAttr b) {
 332             return b.env;
 333         } finally {
 334             breakTree = null;
 335             log.useSource(prev);
 336         }
 337         return env;
 338     }
 339 
 340     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 341         breakTree = tree;
 342         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 343         try {
 344             attribStat(stmt, env);
 345         } catch (BreakAttr b) {
 346             return b.env;
 347         } finally {
 348             breakTree = null;
 349             log.useSource(prev);
 350         }
 351         return env;
 352     }
 353 
 354     private JCTree breakTree = null;
 355 
 356     private static class BreakAttr extends RuntimeException {
 357         static final long serialVersionUID = -6924771130405446405L;
 358         private Env<AttrContext> env;
 359         private BreakAttr(Env<AttrContext> env) {
 360             this.env = env;
 361         }
 362     }
 363 
 364 
 365 /* ************************************************************************
 366  * Visitor methods
 367  *************************************************************************/
 368 
 369     /** Visitor argument: the current environment.
 370      */
 371     Env<AttrContext> env;
 372 
 373     /** Visitor argument: the currently expected proto-kind.
 374      */
 375     int pkind;
 376 
 377     /** Visitor argument: the currently expected proto-type.
 378      */
 379     Type pt;
 380 
 381     /** Visitor result: the computed type.
 382      */
 383     Type result;
 384 
 385     /** Visitor method: attribute a tree, catching any completion failure
 386      *  exceptions. Return the tree's type.
 387      *
 388      *  @param tree    The tree to be visited.
 389      *  @param env     The environment visitor argument.
 390      *  @param pkind   The protokind visitor argument.
 391      *  @param pt      The prototype visitor argument.
 392      */
 393     Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) {
 394         Env<AttrContext> prevEnv = this.env;
 395         int prevPkind = this.pkind;
 396         Type prevPt = this.pt;
 397         try {
 398             this.env = env;
 399             this.pkind = pkind;
 400             this.pt = pt;
 401             tree.accept(this);
 402             if (tree == breakTree)
 403                 throw new BreakAttr(env);
 404             return result;
 405         } catch (CompletionFailure ex) {
 406             tree.type = syms.errType;
 407             return chk.completionError(tree.pos(), ex);
 408         } finally {
 409             this.env = prevEnv;
 410             this.pkind = prevPkind;
 411             this.pt = prevPt;
 412         }
 413     }
 414 
 415     /** Derived visitor method: attribute an expression tree.
 416      */
 417     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 418         return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
 419     }
 420 
 421     /** Derived visitor method: attribute an expression tree with
 422      *  no constraints on the computed type.
 423      */
 424     Type attribExpr(JCTree tree, Env<AttrContext> env) {
 425         return attribTree(tree, env, VAL, Type.noType);
 426     }
 427 
 428     /** Derived visitor method: attribute a type tree.
 429      */
 430     Type attribType(JCTree tree, Env<AttrContext> env) {
 431         Type result = attribType(tree, env, Type.noType);
 432         return result;
 433     }
 434 
 435     /** Derived visitor method: attribute a type tree.
 436      */
 437     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 438         Type result = attribTree(tree, env, TYP, pt);
 439         return result;
 440     }
 441 
 442     /** Derived visitor method: attribute a statement or definition tree.
 443      */
 444     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 445         return attribTree(tree, env, NIL, Type.noType);
 446     }
 447 
 448     /** Attribute a list of expressions, returning a list of types.
 449      */
 450     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 451         ListBuffer<Type> ts = new ListBuffer<Type>();
 452         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 453             ts.append(attribExpr(l.head, env, pt));
 454         return ts.toList();
 455     }
 456 
 457     /** Attribute a list of statements, returning nothing.
 458      */
 459     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 460         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 461             attribStat(l.head, env);
 462     }
 463 
 464     /** Attribute the arguments in a method call, returning a list of types.
 465      */
 466     List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
 467         ListBuffer<Type> argtypes = new ListBuffer<Type>();
 468         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 469             argtypes.append(chk.checkNonVoid(
 470                 l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly))));
 471         return argtypes.toList();
 472     }
 473 
 474     /** Attribute a type argument list, returning a list of types.
 475      *  Caller is responsible for calling checkRefTypes.
 476      */
 477     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 478         ListBuffer<Type> argtypes = new ListBuffer<Type>();
 479         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 480             argtypes.append(attribType(l.head, env));
 481         return argtypes.toList();
 482     }
 483 
 484     /** Attribute a type argument list, returning a list of types.
 485      *  Check that all the types are references.
 486      */
 487     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 488         List<Type> types = attribAnyTypes(trees, env);
 489         return chk.checkRefTypes(trees, types);
 490     }
 491 
 492     /**
 493      * Attribute type variables (of generic classes or methods).
 494      * Compound types are attributed later in attribBounds.
 495      * @param typarams the type variables to enter
 496      * @param env      the current environment
 497      */
 498     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
 499         for (JCTypeParameter tvar : typarams) {
 500             TypeVar a = (TypeVar)tvar.type;
 501             a.tsym.flags_field |= UNATTRIBUTED;
 502             a.bound = Type.noType;
 503             if (!tvar.bounds.isEmpty()) {
 504                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 505                 for (JCExpression bound : tvar.bounds.tail)
 506                     bounds = bounds.prepend(attribType(bound, env));
 507                 types.setBounds(a, bounds.reverse());
 508             } else {
 509                 // if no bounds are given, assume a single bound of
 510                 // java.lang.Object.
 511                 types.setBounds(a, List.of(syms.objectType));
 512             }
 513             a.tsym.flags_field &= ~UNATTRIBUTED;
 514         }
 515         for (JCTypeParameter tvar : typarams)
 516             chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 517         attribStats(typarams, env);
 518     }
 519 
 520     void attribBounds(List<JCTypeParameter> typarams) {
 521         for (JCTypeParameter typaram : typarams) {
 522             Type bound = typaram.type.getUpperBound();
 523             if (bound != null && bound.tsym instanceof ClassSymbol) {
 524                 ClassSymbol c = (ClassSymbol)bound.tsym;
 525                 if ((c.flags_field & COMPOUND) != 0) {
 526                     assert (c.flags_field & UNATTRIBUTED) != 0 : c;
 527                     attribClass(typaram.pos(), c);
 528                 }
 529             }
 530         }
 531     }
 532 
 533     /**
 534      * Attribute the type references in a list of annotations.
 535      */
 536     void attribAnnotationTypes(List<JCAnnotation> annotations,
 537                                Env<AttrContext> env) {
 538         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 539             JCAnnotation a = al.head;
 540             attribType(a.annotationType, env);
 541         }
 542     }
 543 
 544     /** Attribute type reference in an `extends' or `implements' clause.
 545      *
 546      *  @param tree              The tree making up the type reference.
 547      *  @param env               The environment current at the reference.
 548      *  @param classExpected     true if only a class is expected here.
 549      *  @param interfaceExpected true if only an interface is expected here.
 550      */
 551     Type attribBase(JCTree tree,
 552                     Env<AttrContext> env,
 553                     boolean classExpected,
 554                     boolean interfaceExpected,
 555                     boolean checkExtensible) {
 556         Type t = attribType(tree, env);
 557         return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 558     }
 559     Type checkBase(Type t,
 560                    JCTree tree,
 561                    Env<AttrContext> env,
 562                    boolean classExpected,
 563                    boolean interfaceExpected,
 564                    boolean checkExtensible) {
 565         if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
 566             // check that type variable is already visible
 567             if (t.getUpperBound() == null) {
 568                 log.error(tree.pos(), "illegal.forward.ref");
 569                 return types.createErrorType(t);
 570             }
 571         } else {
 572             t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
 573         }
 574         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 575             log.error(tree.pos(), "intf.expected.here");
 576             // return errType is necessary since otherwise there might
 577             // be undetected cycles which cause attribution to loop
 578             return types.createErrorType(t);
 579         } else if (checkExtensible &&
 580                    classExpected &&
 581                    (t.tsym.flags() & INTERFACE) != 0) {
 582             log.error(tree.pos(), "no.intf.expected.here");
 583             return types.createErrorType(t);
 584         }
 585         if (checkExtensible &&
 586             ((t.tsym.flags() & FINAL) != 0)) {
 587             log.error(tree.pos(),
 588                       "cant.inherit.from.final", t.tsym);
 589         }
 590         chk.checkNonCyclic(tree.pos(), t);
 591         return t;
 592     }
 593 
 594     public void visitClassDef(JCClassDecl tree) {
 595         // Local classes have not been entered yet, so we need to do it now:
 596         if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
 597             enter.classEnter(tree, env);
 598 
 599         ClassSymbol c = tree.sym;
 600         if (c == null) {
 601             // exit in case something drastic went wrong during enter.
 602             result = null;
 603         } else {
 604             // make sure class has been completed:
 605             c.complete();
 606 
 607             // If this class appears as an anonymous class
 608             // in a superclass constructor call where
 609             // no explicit outer instance is given,
 610             // disable implicit outer instance from being passed.
 611             // (This would be an illegal access to "this before super").
 612             if (env.info.isSelfCall &&
 613                 env.tree.getTag() == JCTree.NEWCLASS &&
 614                 ((JCNewClass) env.tree).encl == null)
 615             {
 616                 c.flags_field |= NOOUTERTHIS;
 617             }
 618             attribClass(tree.pos(), c);
 619             result = tree.type = c.type;
 620         }
 621     }
 622 
 623     public void visitMethodDef(JCMethodDecl tree) {
 624         MethodSymbol m = tree.sym;
 625 
 626         Lint lint = env.info.lint.augment(m.attributes_field, m.flags());
 627         Lint prevLint = chk.setLint(lint);
 628         try {
 629             chk.checkDeprecatedAnnotation(tree.pos(), m);
 630 
 631             attribBounds(tree.typarams);
 632 
 633             // If we override any other methods, check that we do so properly.
 634             // JLS ???
 635             chk.checkOverride(tree, m);
 636 
 637             // Create a new environment with local scope
 638             // for attributing the method.
 639             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
 640 
 641             localEnv.info.lint = lint;
 642 
 643             // Enter all type parameters into the local method scope.
 644             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
 645                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
 646 
 647             ClassSymbol owner = env.enclClass.sym;
 648             if ((owner.flags() & ANNOTATION) != 0 &&
 649                 tree.params.nonEmpty())
 650                 log.error(tree.params.head.pos(),
 651                           "intf.annotation.members.cant.have.params");
 652 
 653             // Attribute all value parameters.
 654             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
 655                 attribStat(l.head, localEnv);
 656             }
 657 
 658             // Check that type parameters are well-formed.
 659             chk.validate(tree.typarams, localEnv);
 660             if ((owner.flags() & ANNOTATION) != 0 &&
 661                 tree.typarams.nonEmpty())
 662                 log.error(tree.typarams.head.pos(),
 663                           "intf.annotation.members.cant.have.type.params");
 664 
 665             // Check that result type is well-formed.
 666             chk.validate(tree.restype, localEnv);
 667             if ((owner.flags() & ANNOTATION) != 0)
 668                 chk.validateAnnotationType(tree.restype);
 669 
 670             if ((owner.flags() & ANNOTATION) != 0)
 671                 chk.validateAnnotationMethod(tree.pos(), m);
 672 
 673             // Check that all exceptions mentioned in the throws clause extend
 674             // java.lang.Throwable.
 675             if ((owner.flags() & ANNOTATION) != 0 && tree.thrown.nonEmpty())
 676                 log.error(tree.thrown.head.pos(),
 677                           "throws.not.allowed.in.intf.annotation");
 678             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
 679                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
 680 
 681             if (tree.body == null) {
 682                 // Empty bodies are only allowed for
 683                 // abstract, native, or interface methods, or for methods
 684                 // in a retrofit signature class.
 685                 if ((owner.flags() & INTERFACE) == 0 &&
 686                     (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 &&
 687                     !relax)
 688                     log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
 689                 if (tree.defaultValue != null) {
 690                     if ((owner.flags() & ANNOTATION) == 0)
 691                         log.error(tree.pos(),
 692                                   "default.allowed.in.intf.annotation.member");
 693                 }
 694             } else if ((owner.flags() & INTERFACE) != 0) {
 695                 log.error(tree.body.pos(), "intf.meth.cant.have.body");
 696             } else if ((tree.mods.flags & ABSTRACT) != 0) {
 697                 log.error(tree.pos(), "abstract.meth.cant.have.body");
 698             } else if ((tree.mods.flags & NATIVE) != 0) {
 699                 log.error(tree.pos(), "native.meth.cant.have.body");
 700             } else {
 701                 // Add an implicit super() call unless an explicit call to
 702                 // super(...) or this(...) is given
 703                 // or we are compiling class java.lang.Object.
 704                 if (tree.name == names.init && owner.type != syms.objectType) {
 705                     JCBlock body = tree.body;
 706                     if (body.stats.isEmpty() ||
 707                         !TreeInfo.isSelfCall(body.stats.head)) {
 708                         body.stats = body.stats.
 709                             prepend(memberEnter.SuperCall(make.at(body.pos),
 710                                                           List.<Type>nil(),
 711                                                           List.<JCVariableDecl>nil(),
 712                                                           false));
 713                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
 714                                (tree.mods.flags & GENERATEDCONSTR) == 0 &&
 715                                TreeInfo.isSuperCall(body.stats.head)) {
 716                         // enum constructors are not allowed to call super
 717                         // directly, so make sure there aren't any super calls
 718                         // in enum constructors, except in the compiler
 719                         // generated one.
 720                         log.error(tree.body.stats.head.pos(),
 721                                   "call.to.super.not.allowed.in.enum.ctor",
 722                                   env.enclClass.sym);
 723                     }
 724                 }
 725 
 726                 // Attribute method body.
 727                 attribStat(tree.body, localEnv);
 728             }
 729             localEnv.info.scope.leave();
 730             result = tree.type = m.type;
 731             chk.validateAnnotations(tree.mods.annotations, m);
 732         }
 733         finally {
 734             chk.setLint(prevLint);
 735         }
 736     }
 737 
 738     public void visitVarDef(JCVariableDecl tree) {
 739         // Local variables have not been entered yet, so we need to do it now:
 740         if (env.info.scope.owner.kind == MTH) {
 741             if (tree.sym != null) {
 742                 // parameters have already been entered
 743                 env.info.scope.enter(tree.sym);
 744             } else {
 745                 memberEnter.memberEnter(tree, env);
 746                 annotate.flush();
 747             }
 748         }
 749 
 750         VarSymbol v = tree.sym;
 751         Lint lint = env.info.lint.augment(v.attributes_field, v.flags());
 752         Lint prevLint = chk.setLint(lint);
 753 
 754         // Check that the variable's declared type is well-formed.
 755         chk.validate(tree.vartype, env);
 756 
 757         try {
 758             chk.checkDeprecatedAnnotation(tree.pos(), v);
 759 
 760             if (tree.init != null) {
 761                 if ((v.flags_field & FINAL) != 0 && tree.init.getTag() != JCTree.NEWCLASS) {
 762                     // In this case, `v' is final.  Ensure that it's initializer is
 763                     // evaluated.
 764                     v.getConstValue(); // ensure initializer is evaluated
 765                 } else {
 766                     // Attribute initializer in a new environment
 767                     // with the declared variable as owner.
 768                     // Check that initializer conforms to variable's declared type.
 769                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
 770                     initEnv.info.lint = lint;
 771                     // In order to catch self-references, we set the variable's
 772                     // declaration position to maximal possible value, effectively
 773                     // marking the variable as undefined.
 774                     initEnv.info.enclVar = v;
 775                     attribExpr(tree.init, initEnv, v.type);
 776                 }
 777             }
 778             result = tree.type = v.type;
 779             chk.validateAnnotations(tree.mods.annotations, v);
 780         }
 781         finally {
 782             chk.setLint(prevLint);
 783         }
 784     }
 785 
 786     public void visitSkip(JCSkip tree) {
 787         result = null;
 788     }
 789 
 790     public void visitBlock(JCBlock tree) {
 791         if (env.info.scope.owner.kind == TYP) {
 792             // Block is a static or instance initializer;
 793             // let the owner of the environment be a freshly
 794             // created BLOCK-method.
 795             Env<AttrContext> localEnv =
 796                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
 797             localEnv.info.scope.owner =
 798                 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
 799                                  env.info.scope.owner);
 800             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
 801             attribStats(tree.stats, localEnv);
 802         } else {
 803             // Create a new local environment with a local scope.
 804             Env<AttrContext> localEnv =
 805                 env.dup(tree, env.info.dup(env.info.scope.dup()));
 806             attribStats(tree.stats, localEnv);
 807             localEnv.info.scope.leave();
 808         }
 809         result = null;
 810     }
 811 
 812     public void visitDoLoop(JCDoWhileLoop tree) {
 813         attribStat(tree.body, env.dup(tree));
 814         attribExpr(tree.cond, env, syms.booleanType);
 815         result = null;
 816     }
 817 
 818     public void visitWhileLoop(JCWhileLoop tree) {
 819         attribExpr(tree.cond, env, syms.booleanType);
 820         attribStat(tree.body, env.dup(tree));
 821         result = null;
 822     }
 823 
 824     public void visitForLoop(JCForLoop tree) {
 825         Env<AttrContext> loopEnv =
 826             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
 827         attribStats(tree.init, loopEnv);
 828         if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
 829         loopEnv.tree = tree; // before, we were not in loop!
 830         attribStats(tree.step, loopEnv);
 831         attribStat(tree.body, loopEnv);
 832         loopEnv.info.scope.leave();
 833         result = null;
 834     }
 835 
 836     public void visitForeachLoop(JCEnhancedForLoop tree) {
 837         Env<AttrContext> loopEnv =
 838             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
 839         attribStat(tree.var, loopEnv);
 840         Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
 841         chk.checkNonVoid(tree.pos(), exprType);
 842         Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
 843         if (elemtype == null) {
 844             // or perhaps expr implements Iterable<T>?
 845             Type base = types.asSuper(exprType, syms.iterableType.tsym);
 846             if (base == null) {
 847                 log.error(tree.expr.pos(), "foreach.not.applicable.to.type");
 848                 elemtype = types.createErrorType(exprType);
 849             } else {
 850                 List<Type> iterableParams = base.allparams();
 851                 elemtype = iterableParams.isEmpty()
 852                     ? syms.objectType
 853                     : types.upperBound(iterableParams.head);
 854             }
 855         }
 856         chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
 857         loopEnv.tree = tree; // before, we were not in loop!
 858         attribStat(tree.body, loopEnv);
 859         loopEnv.info.scope.leave();
 860         result = null;
 861     }
 862 
 863     public void visitLabelled(JCLabeledStatement tree) {
 864         // Check that label is not used in an enclosing statement
 865         Env<AttrContext> env1 = env;
 866         while (env1 != null && env1.tree.getTag() != JCTree.CLASSDEF) {
 867             if (env1.tree.getTag() == JCTree.LABELLED &&
 868                 ((JCLabeledStatement) env1.tree).label == tree.label) {
 869                 log.error(tree.pos(), "label.already.in.use",
 870                           tree.label);
 871                 break;
 872             }
 873             env1 = env1.next;
 874         }
 875 
 876         attribStat(tree.body, env.dup(tree));
 877         result = null;
 878     }
 879 
 880     public void visitSwitch(JCSwitch tree) {
 881         Type seltype = attribExpr(tree.selector, env);
 882 
 883         Env<AttrContext> switchEnv =
 884             env.dup(tree, env.info.dup(env.info.scope.dup()));
 885 
 886         boolean enumSwitch =
 887             allowEnums &&
 888             (seltype.tsym.flags() & Flags.ENUM) != 0;
 889         if (!enumSwitch)
 890             seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
 891 
 892         // Attribute all cases and
 893         // check that there are no duplicate case labels or default clauses.
 894         Set<Object> labels = new HashSet<Object>(); // The set of case labels.
 895         boolean hasDefault = false;      // Is there a default label?
 896         for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
 897             JCCase c = l.head;
 898             Env<AttrContext> caseEnv =
 899                 switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
 900             if (c.pat != null) {
 901                 if (enumSwitch) {
 902                     Symbol sym = enumConstant(c.pat, seltype);
 903                     if (sym == null) {
 904                         log.error(c.pat.pos(), "enum.const.req");
 905                     } else if (!labels.add(sym)) {
 906                         log.error(c.pos(), "duplicate.case.label");
 907                     }
 908                 } else {
 909                     Type pattype = attribExpr(c.pat, switchEnv, seltype);
 910                     if (pattype.tag != ERROR) {
 911                         if (pattype.constValue() == null) {
 912                             log.error(c.pat.pos(), "const.expr.req");
 913                         } else if (labels.contains(pattype.constValue())) {
 914                             log.error(c.pos(), "duplicate.case.label");
 915                         } else {
 916                             labels.add(pattype.constValue());
 917                         }
 918                     }
 919                 }
 920             } else if (hasDefault) {
 921                 log.error(c.pos(), "duplicate.default.label");
 922             } else {
 923                 hasDefault = true;
 924             }
 925             attribStats(c.stats, caseEnv);
 926             caseEnv.info.scope.leave();
 927             addVars(c.stats, switchEnv.info.scope);
 928         }
 929 
 930         switchEnv.info.scope.leave();
 931         result = null;
 932     }
 933     // where
 934         /** Add any variables defined in stats to the switch scope. */
 935         private static void addVars(List<JCStatement> stats, Scope switchScope) {
 936             for (;stats.nonEmpty(); stats = stats.tail) {
 937                 JCTree stat = stats.head;
 938                 if (stat.getTag() == JCTree.VARDEF)
 939                     switchScope.enter(((JCVariableDecl) stat).sym);
 940             }
 941         }
 942     // where
 943     /** Return the selected enumeration constant symbol, or null. */
 944     private Symbol enumConstant(JCTree tree, Type enumType) {
 945         if (tree.getTag() != JCTree.IDENT) {
 946             log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
 947             return syms.errSymbol;
 948         }
 949         JCIdent ident = (JCIdent)tree;
 950         Name name = ident.name;
 951         for (Scope.Entry e = enumType.tsym.members().lookup(name);
 952              e.scope != null; e = e.next()) {
 953             if (e.sym.kind == VAR) {
 954                 Symbol s = ident.sym = e.sym;
 955                 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
 956                 ident.type = s.type;
 957                 return ((s.flags_field & Flags.ENUM) == 0)
 958                     ? null : s;
 959             }
 960         }
 961         return null;
 962     }
 963 
 964     public void visitSynchronized(JCSynchronized tree) {
 965         chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
 966         attribStat(tree.body, env);
 967         result = null;
 968     }
 969 
 970     public void visitTry(JCTry tree) {
 971         // Attribute body
 972         attribStat(tree.body, env.dup(tree, env.info.dup()));
 973 
 974         // Attribute catch clauses
 975         for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
 976             JCCatch c = l.head;
 977             Env<AttrContext> catchEnv =
 978                 env.dup(c, env.info.dup(env.info.scope.dup()));
 979             Type ctype = attribStat(c.param, catchEnv);
 980             if (c.param.type.tsym.kind == Kinds.VAR) {
 981                 c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
 982             }
 983             chk.checkType(c.param.vartype.pos(),
 984                           chk.checkClassType(c.param.vartype.pos(), ctype),
 985                           syms.throwableType);
 986             attribStat(c.body, catchEnv);
 987             catchEnv.info.scope.leave();
 988         }
 989 
 990         // Attribute finalizer
 991         if (tree.finalizer != null) attribStat(tree.finalizer, env);
 992         result = null;
 993     }
 994 
 995     public void visitConditional(JCConditional tree) {
 996         attribExpr(tree.cond, env, syms.booleanType);
 997         attribExpr(tree.truepart, env);
 998         attribExpr(tree.falsepart, env);
 999         result = check(tree,
1000                        capture(condType(tree.pos(), tree.cond.type,
1001                                         tree.truepart.type, tree.falsepart.type)),
1002                        VAL, pkind, pt);
1003     }
1004     //where
1005         /** Compute the type of a conditional expression, after
1006          *  checking that it exists. See Spec 15.25.
1007          *
1008          *  @param pos      The source position to be used for
1009          *                  error diagnostics.
1010          *  @param condtype The type of the expression's condition.
1011          *  @param thentype The type of the expression's then-part.
1012          *  @param elsetype The type of the expression's else-part.
1013          */
1014         private Type condType(DiagnosticPosition pos,
1015                               Type condtype,
1016                               Type thentype,
1017                               Type elsetype) {
1018             Type ctype = condType1(pos, condtype, thentype, elsetype);
1019 
1020             // If condition and both arms are numeric constants,
1021             // evaluate at compile-time.
1022             return ((condtype.constValue() != null) &&
1023                     (thentype.constValue() != null) &&
1024                     (elsetype.constValue() != null))
1025                 ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype)
1026                 : ctype;
1027         }
1028         /** Compute the type of a conditional expression, after
1029          *  checking that it exists.  Does not take into
1030          *  account the special case where condition and both arms
1031          *  are constants.
1032          *
1033          *  @param pos      The source position to be used for error
1034          *                  diagnostics.
1035          *  @param condtype The type of the expression's condition.
1036          *  @param thentype The type of the expression's then-part.
1037          *  @param elsetype The type of the expression's else-part.
1038          */
1039         private Type condType1(DiagnosticPosition pos, Type condtype,
1040                                Type thentype, Type elsetype) {
1041             // If same type, that is the result
1042             if (types.isSameType(thentype, elsetype))
1043                 return thentype.baseType();
1044 
1045             Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
1046                 ? thentype : types.unboxedType(thentype);
1047             Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
1048                 ? elsetype : types.unboxedType(elsetype);
1049 
1050             // Otherwise, if both arms can be converted to a numeric
1051             // type, return the least numeric type that fits both arms
1052             // (i.e. return larger of the two, or return int if one
1053             // arm is short, the other is char).
1054             if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
1055                 // If one arm has an integer subrange type (i.e., byte,
1056                 // short, or char), and the other is an integer constant
1057                 // that fits into the subrange, return the subrange type.
1058                 if (thenUnboxed.tag < INT && elseUnboxed.tag == INT &&
1059                     types.isAssignable(elseUnboxed, thenUnboxed))
1060                     return thenUnboxed.baseType();
1061                 if (elseUnboxed.tag < INT && thenUnboxed.tag == INT &&
1062                     types.isAssignable(thenUnboxed, elseUnboxed))
1063                     return elseUnboxed.baseType();
1064 
1065                 for (int i = BYTE; i < VOID; i++) {
1066                     Type candidate = syms.typeOfTag[i];
1067                     if (types.isSubtype(thenUnboxed, candidate) &&
1068                         types.isSubtype(elseUnboxed, candidate))
1069                         return candidate;
1070                 }
1071             }
1072 
1073             // Those were all the cases that could result in a primitive
1074             if (allowBoxing) {
1075                 if (thentype.isPrimitive())
1076                     thentype = types.boxedClass(thentype).type;
1077                 if (elsetype.isPrimitive())
1078                     elsetype = types.boxedClass(elsetype).type;
1079             }
1080 
1081             if (types.isSubtype(thentype, elsetype))
1082                 return elsetype.baseType();
1083             if (types.isSubtype(elsetype, thentype))
1084                 return thentype.baseType();
1085 
1086             if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
1087                 log.error(pos, "neither.conditional.subtype",
1088                           thentype, elsetype);
1089                 return thentype.baseType();
1090             }
1091 
1092             // both are known to be reference types.  The result is
1093             // lub(thentype,elsetype). This cannot fail, as it will
1094             // always be possible to infer "Object" if nothing better.
1095             return types.lub(thentype.baseType(), elsetype.baseType());
1096         }
1097 
1098     public void visitIf(JCIf tree) {
1099         attribExpr(tree.cond, env, syms.booleanType);
1100         attribStat(tree.thenpart, env);
1101         if (tree.elsepart != null)
1102             attribStat(tree.elsepart, env);
1103         chk.checkEmptyIf(tree);
1104         result = null;
1105     }
1106 
1107     public void visitExec(JCExpressionStatement tree) {
1108         attribExpr(tree.expr, env);
1109         result = null;
1110     }
1111 
1112     public void visitBreak(JCBreak tree) {
1113         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1114         result = null;
1115     }
1116 
1117     public void visitContinue(JCContinue tree) {
1118         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
1119         result = null;
1120     }
1121     //where
1122         /** Return the target of a break or continue statement, if it exists,
1123          *  report an error if not.
1124          *  Note: The target of a labelled break or continue is the
1125          *  (non-labelled) statement tree referred to by the label,
1126          *  not the tree representing the labelled statement itself.
1127          *
1128          *  @param pos     The position to be used for error diagnostics
1129          *  @param tag     The tag of the jump statement. This is either
1130          *                 Tree.BREAK or Tree.CONTINUE.
1131          *  @param label   The label of the jump statement, or null if no
1132          *                 label is given.
1133          *  @param env     The environment current at the jump statement.
1134          */
1135         private JCTree findJumpTarget(DiagnosticPosition pos,
1136                                     int tag,
1137                                     Name label,
1138                                     Env<AttrContext> env) {
1139             // Search environments outwards from the point of jump.
1140             Env<AttrContext> env1 = env;
1141             LOOP:
1142             while (env1 != null) {
1143                 switch (env1.tree.getTag()) {
1144                 case JCTree.LABELLED:
1145                     JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
1146                     if (label == labelled.label) {
1147                         // If jump is a continue, check that target is a loop.
1148                         if (tag == JCTree.CONTINUE) {
1149                             if (labelled.body.getTag() != JCTree.DOLOOP &&
1150                                 labelled.body.getTag() != JCTree.WHILELOOP &&
1151                                 labelled.body.getTag() != JCTree.FORLOOP &&
1152                                 labelled.body.getTag() != JCTree.FOREACHLOOP)
1153                                 log.error(pos, "not.loop.label", label);
1154                             // Found labelled statement target, now go inwards
1155                             // to next non-labelled tree.
1156                             return TreeInfo.referencedStatement(labelled);
1157                         } else {
1158                             return labelled;
1159                         }
1160                     }
1161                     break;
1162                 case JCTree.DOLOOP:
1163                 case JCTree.WHILELOOP:
1164                 case JCTree.FORLOOP:
1165                 case JCTree.FOREACHLOOP:
1166                     if (label == null) return env1.tree;
1167                     break;
1168                 case JCTree.SWITCH:
1169                     if (label == null && tag == JCTree.BREAK) return env1.tree;
1170                     break;
1171                 case JCTree.METHODDEF:
1172                 case JCTree.CLASSDEF:
1173                     break LOOP;
1174                 default:
1175                 }
1176                 env1 = env1.next;
1177             }
1178             if (label != null)
1179                 log.error(pos, "undef.label", label);
1180             else if (tag == JCTree.CONTINUE)
1181                 log.error(pos, "cont.outside.loop");
1182             else
1183                 log.error(pos, "break.outside.switch.loop");
1184             return null;
1185         }
1186 
1187     public void visitReturn(JCReturn tree) {
1188         // Check that there is an enclosing method which is
1189         // nested within than the enclosing class.
1190         if (env.enclMethod == null ||
1191             env.enclMethod.sym.owner != env.enclClass.sym) {
1192             log.error(tree.pos(), "ret.outside.meth");
1193 
1194         } else {
1195             // Attribute return expression, if it exists, and check that
1196             // it conforms to result type of enclosing method.
1197             Symbol m = env.enclMethod.sym;
1198             if (m.type.getReturnType().tag == VOID) {
1199                 if (tree.expr != null)
1200                     log.error(tree.expr.pos(),
1201                               "cant.ret.val.from.meth.decl.void");
1202             } else if (tree.expr == null) {
1203                 log.error(tree.pos(), "missing.ret.val");
1204             } else {
1205                 attribExpr(tree.expr, env, m.type.getReturnType());
1206             }
1207         }
1208         result = null;
1209     }
1210 
1211     public void visitThrow(JCThrow tree) {
1212         attribExpr(tree.expr, env, syms.throwableType);
1213         result = null;
1214     }
1215 
1216     public void visitAssert(JCAssert tree) {
1217         attribExpr(tree.cond, env, syms.booleanType);
1218         if (tree.detail != null) {
1219             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
1220         }
1221         result = null;
1222     }
1223 
1224      /** Visitor method for method invocations.
1225      *  NOTE: The method part of an application will have in its type field
1226      *        the return type of the method, not the method's type itself!
1227      */
1228     public void visitApply(JCMethodInvocation tree) {
1229         // The local environment of a method application is
1230         // a new environment nested in the current one.
1231         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1232 
1233         // The types of the actual method arguments.
1234         List<Type> argtypes;
1235 
1236         // The types of the actual method type arguments.
1237         List<Type> typeargtypes = null;
1238         boolean typeargtypesNonRefOK = false;
1239 
1240         Name methName = TreeInfo.name(tree.meth);
1241 
1242         boolean isConstructorCall =
1243             methName == names._this || methName == names._super;
1244 
1245         if (isConstructorCall) {
1246             // We are seeing a ...this(...) or ...super(...) call.
1247             // Check that this is the first statement in a constructor.
1248             if (checkFirstConstructorStat(tree, env)) {
1249 
1250                 // Record the fact
1251                 // that this is a constructor call (using isSelfCall).
1252                 localEnv.info.isSelfCall = true;
1253 
1254                 // Attribute arguments, yielding list of argument types.
1255                 argtypes = attribArgs(tree.args, localEnv);
1256                 typeargtypes = attribTypes(tree.typeargs, localEnv);
1257 
1258                 // Variable `site' points to the class in which the called
1259                 // constructor is defined.
1260                 Type site = env.enclClass.sym.type;
1261                 if (methName == names._super) {
1262                     if (site == syms.objectType) {
1263                         log.error(tree.meth.pos(), "no.superclass", site);
1264                         site = types.createErrorType(syms.objectType);
1265                     } else {
1266                         site = types.supertype(site);
1267                     }
1268                 }
1269 
1270                 if (site.tag == CLASS) {
1271                     Type encl = site.getEnclosingType();
1272                     while (encl != null && encl.tag == TYPEVAR)
1273                         encl = encl.getUpperBound();
1274                     if (encl.tag == CLASS) {
1275                         // we are calling a nested class
1276 
1277                         if (tree.meth.getTag() == JCTree.SELECT) {
1278                             JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
1279 
1280                             // We are seeing a prefixed call, of the form
1281                             //     <expr>.super(...).
1282                             // Check that the prefix expression conforms
1283                             // to the outer instance type of the class.
1284                             chk.checkRefType(qualifier.pos(),
1285                                              attribExpr(qualifier, localEnv,
1286                                                         encl));
1287                         } else if (methName == names._super) {
1288                             // qualifier omitted; check for existence
1289                             // of an appropriate implicit qualifier.
1290                             rs.resolveImplicitThis(tree.meth.pos(),
1291                                                    localEnv, site);
1292                         }
1293                     } else if (tree.meth.getTag() == JCTree.SELECT) {
1294                         log.error(tree.meth.pos(), "illegal.qual.not.icls",
1295                                   site.tsym);
1296                     }
1297 
1298                     // if we're calling a java.lang.Enum constructor,
1299                     // prefix the implicit String and int parameters
1300                     if (site.tsym == syms.enumSym && allowEnums)
1301                         argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
1302 
1303                     // Resolve the called constructor under the assumption
1304                     // that we are referring to a superclass instance of the
1305                     // current instance (JLS ???).
1306                     boolean selectSuperPrev = localEnv.info.selectSuper;
1307                     localEnv.info.selectSuper = true;
1308                     localEnv.info.varArgs = false;
1309                     Symbol sym = rs.resolveConstructor(
1310                         tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
1311                     localEnv.info.selectSuper = selectSuperPrev;
1312 
1313                     // Set method symbol to resolved constructor...
1314                     TreeInfo.setSymbol(tree.meth, sym);
1315 
1316                     // ...and check that it is legal in the current context.
1317                     // (this will also set the tree's type)
1318                     Type mpt = newMethTemplate(argtypes, typeargtypes);
1319                     checkId(tree.meth, site, sym, localEnv, MTH,
1320                             mpt, tree.varargsElement != null);
1321                 }
1322                 // Otherwise, `site' is an error type and we do nothing
1323             }
1324             result = tree.type = syms.voidType;
1325         } else {
1326             // Otherwise, we are seeing a regular method call.
1327             // Attribute the arguments, yielding list of argument types, ...
1328             argtypes = attribArgs(tree.args, localEnv);
1329             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
1330 
1331             // ... and attribute the method using as a prototype a methodtype
1332             // whose formal argument types is exactly the list of actual
1333             // arguments (this will also set the method symbol).
1334             Type mpt = newMethTemplate(argtypes, typeargtypes);
1335             localEnv.info.varArgs = false;
1336             Type mtype = attribExpr(tree.meth, localEnv, mpt);
1337             if (localEnv.info.varArgs)
1338                 assert mtype.isErroneous() || tree.varargsElement != null;
1339 
1340             // Compute the result type.
1341             Type restype = mtype.getReturnType();
1342             assert restype.tag != WILDCARD : mtype;
1343 
1344             // as a special case, array.clone() has a result that is
1345             // the same as static type of the array being cloned
1346             if (tree.meth.getTag() == JCTree.SELECT &&
1347                 allowCovariantReturns &&
1348                 methName == names.clone &&
1349                 types.isArray(((JCFieldAccess) tree.meth).selected.type))
1350                 restype = ((JCFieldAccess) tree.meth).selected.type;
1351 
1352             // as a special case, x.getClass() has type Class<? extends |X|>
1353             if (allowGenerics &&
1354                 methName == names.getClass && tree.args.isEmpty()) {
1355                 Type qualifier = (tree.meth.getTag() == JCTree.SELECT)
1356                     ? ((JCFieldAccess) tree.meth).selected.type
1357                     : env.enclClass.sym.type;
1358                 restype = new
1359                     ClassType(restype.getEnclosingType(),
1360                               List.<Type>of(new WildcardType(types.erasure(qualifier),
1361                                                                BoundKind.EXTENDS,
1362                                                                syms.boundClass)),
1363                               restype.tsym);
1364             }
1365 
1366             // as a special case, MethodHandle.<T>invoke(abc) and InvokeDynamic.<T>foo(abc)
1367             // has type <T>, and T can be a primitive type.
1368             if (tree.meth.getTag() == JCTree.SELECT && !typeargtypes.isEmpty()) {
1369               Type selt = ((JCFieldAccess) tree.meth).selected.type;
1370               if ((selt == syms.methodHandleType && methName == names.invoke) || selt == syms.invokeDynamicType) {
1371                   assert types.isSameType(restype, typeargtypes.head) : mtype;
1372                   typeargtypesNonRefOK = true;
1373               }
1374             }
1375 
1376             if (!typeargtypesNonRefOK) {
1377                 chk.checkRefTypes(tree.typeargs, typeargtypes);
1378             }
1379 
1380             // Check that value of resulting type is admissible in the
1381             // current context.  Also, capture the return type
1382             result = checkReturn(tree, capture(restype), VAL, pkind, pt);
1383         }
1384         chk.validate(tree.typeargs, localEnv);
1385     }
1386     //where
1387         /** Check that given application node appears as first statement
1388          *  in a constructor call.
1389          *  @param tree   The application node
1390          *  @param env    The environment current at the application.
1391          */
1392         boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
1393             JCMethodDecl enclMethod = env.enclMethod;
1394             if (enclMethod != null && enclMethod.name == names.init) {
1395                 JCBlock body = enclMethod.body;
1396                 if (body.stats.head.getTag() == JCTree.EXEC &&
1397                     ((JCExpressionStatement) body.stats.head).expr == tree)
1398                     return true;
1399             }
1400             log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
1401                       TreeInfo.name(tree.meth));
1402             return false;
1403         }
1404 
1405         /** Obtain a method type with given argument types.
1406          */
1407         Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
1408             MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
1409             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
1410         }
1411 
1412     public void visitNewClass(JCNewClass tree) {
1413         Type owntype = types.createErrorType(tree.type);
1414 
1415         // The local environment of a class creation is
1416         // a new environment nested in the current one.
1417         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
1418 
1419         // The anonymous inner class definition of the new expression,
1420         // if one is defined by it.
1421         JCClassDecl cdef = tree.def;
1422 
1423         // If enclosing class is given, attribute it, and
1424         // complete class name to be fully qualified
1425         JCExpression clazz = tree.clazz; // Class field following new
1426         JCExpression clazzid =          // Identifier in class field
1427             (clazz.getTag() == JCTree.TYPEAPPLY)
1428             ? ((JCTypeApply) clazz).clazz
1429             : clazz;
1430 
1431         JCExpression clazzid1 = clazzid; // The same in fully qualified form
1432 
1433         if (tree.encl != null) {
1434             // We are seeing a qualified new, of the form
1435             //    <expr>.new C <...> (...) ...
1436             // In this case, we let clazz stand for the name of the
1437             // allocated class C prefixed with the type of the qualifier
1438             // expression, so that we can
1439             // resolve it with standard techniques later. I.e., if
1440             // <expr> has type T, then <expr>.new C <...> (...)
1441             // yields a clazz T.C.
1442             Type encltype = chk.checkRefType(tree.encl.pos(),
1443                                              attribExpr(tree.encl, env));
1444             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
1445                                                  ((JCIdent) clazzid).name);
1446             if (clazz.getTag() == JCTree.TYPEAPPLY)
1447                 clazz = make.at(tree.pos).
1448                     TypeApply(clazzid1,
1449                               ((JCTypeApply) clazz).arguments);
1450             else
1451                 clazz = clazzid1;
1452 //          System.out.println(clazz + " generated.");//DEBUG
1453         }
1454 
1455         // Attribute clazz expression and store
1456         // symbol + type back into the attributed tree.
1457         Type clazztype = attribType(clazz, env);
1458         chk.validate(clazz, localEnv);
1459         clazztype = chk.checkNewClassType(clazz.pos(), clazztype, true, pt);
1460         if (tree.encl != null) {
1461             // We have to work in this case to store
1462             // symbol + type back into the attributed tree.
1463             tree.clazz.type = clazztype;
1464             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
1465             clazzid.type = ((JCIdent) clazzid).sym.type;
1466             if (!clazztype.isErroneous()) {
1467                 if (cdef != null && clazztype.tsym.isInterface()) {
1468                     log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
1469                 } else if (clazztype.tsym.isStatic()) {
1470                     log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
1471                 }
1472             }
1473         } else if (!clazztype.tsym.isInterface() &&
1474                    clazztype.getEnclosingType().tag == CLASS) {
1475             // Check for the existence of an apropos outer instance
1476             rs.resolveImplicitThis(tree.pos(), env, clazztype);
1477         }
1478 
1479         // Attribute constructor arguments.
1480         List<Type> argtypes = attribArgs(tree.args, localEnv);
1481         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
1482 
1483         // If we have made no mistakes in the class type...
1484         if (clazztype.tag == CLASS) {
1485             // Enums may not be instantiated except implicitly
1486             if (allowEnums &&
1487                 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
1488                 (env.tree.getTag() != JCTree.VARDEF ||
1489                  (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
1490                  ((JCVariableDecl) env.tree).init != tree))
1491                 log.error(tree.pos(), "enum.cant.be.instantiated");
1492             // Check that class is not abstract
1493             if (cdef == null &&
1494                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
1495                 log.error(tree.pos(), "abstract.cant.be.instantiated",
1496                           clazztype.tsym);
1497             } else if (cdef != null && clazztype.tsym.isInterface()) {
1498                 // Check that no constructor arguments are given to
1499                 // anonymous classes implementing an interface
1500                 if (!argtypes.isEmpty())
1501                     log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
1502 
1503                 if (!typeargtypes.isEmpty())
1504                     log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
1505 
1506                 // Error recovery: pretend no arguments were supplied.
1507                 argtypes = List.nil();
1508                 typeargtypes = List.nil();
1509             }
1510 
1511             // Resolve the called constructor under the assumption
1512             // that we are referring to a superclass instance of the
1513             // current instance (JLS ???).
1514             else {
1515                 localEnv.info.selectSuper = cdef != null;
1516                 localEnv.info.varArgs = false;
1517                 tree.constructor = rs.resolveConstructor(
1518                     tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
1519                 tree.constructorType = checkMethod(clazztype,
1520                                             tree.constructor,
1521                                             localEnv,
1522                                             tree.args,
1523                                             argtypes,
1524                                             typeargtypes,
1525                                             localEnv.info.varArgs);
1526                 if (localEnv.info.varArgs)
1527                     assert tree.constructorType.isErroneous() || tree.varargsElement != null;
1528             }
1529 
1530             if (cdef != null) {
1531                 // We are seeing an anonymous class instance creation.
1532                 // In this case, the class instance creation
1533                 // expression
1534                 //
1535                 //    E.new <typeargs1>C<typargs2>(args) { ... }
1536                 //
1537                 // is represented internally as
1538                 //
1539                 //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
1540                 //
1541                 // This expression is then *transformed* as follows:
1542                 //
1543                 // (1) add a STATIC flag to the class definition
1544                 //     if the current environment is static
1545                 // (2) add an extends or implements clause
1546                 // (3) add a constructor.
1547                 //
1548                 // For instance, if C is a class, and ET is the type of E,
1549                 // the expression
1550                 //
1551                 //    E.new <typeargs1>C<typargs2>(args) { ... }
1552                 //
1553                 // is translated to (where X is a fresh name and typarams is the
1554                 // parameter list of the super constructor):
1555                 //
1556                 //   new <typeargs1>X(<*nullchk*>E, args) where
1557                 //     X extends C<typargs2> {
1558                 //       <typarams> X(ET e, args) {
1559                 //         e.<typeargs1>super(args)
1560                 //       }
1561                 //       ...
1562                 //     }
1563                 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
1564                 clazz = TreeInfo.isDiamond(tree) ?
1565                     make.Type(clazztype)
1566                     : clazz;
1567                 if (clazztype.tsym.isInterface()) {
1568                     cdef.implementing = List.of(clazz);
1569                 } else {
1570                     cdef.extending = clazz;
1571                 }
1572 
1573                 attribStat(cdef, localEnv);
1574 
1575                 // If an outer instance is given,
1576                 // prefix it to the constructor arguments
1577                 // and delete it from the new expression
1578                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
1579                     tree.args = tree.args.prepend(makeNullCheck(tree.encl));
1580                     argtypes = argtypes.prepend(tree.encl.type);
1581                     tree.encl = null;
1582                 }
1583 
1584                 // Reassign clazztype and recompute constructor.
1585                 clazztype = cdef.sym.type;
1586                 Symbol sym = rs.resolveConstructor(
1587                     tree.pos(), localEnv, clazztype, argtypes,
1588                     typeargtypes, true, tree.varargsElement != null);
1589                 assert sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous();
1590                 tree.constructor = sym;
1591                 if (tree.constructor.kind > ERRONEOUS) {
1592                     tree.constructorType =  syms.errType;
1593                 }
1594                 else {
1595                     tree.constructorType = checkMethod(clazztype,
1596                             tree.constructor,
1597                             localEnv,
1598                             tree.args,
1599                             argtypes,
1600                             typeargtypes,
1601                             localEnv.info.varArgs);
1602                 }
1603             }
1604 
1605             if (tree.constructor != null && tree.constructor.kind == MTH)
1606                 owntype = clazztype;
1607         }
1608         result = check(tree, owntype, VAL, pkind, pt);
1609         chk.validate(tree.typeargs, localEnv);
1610     }
1611 
1612     /** Make an attributed null check tree.
1613      */
1614     public JCExpression makeNullCheck(JCExpression arg) {
1615         // optimization: X.this is never null; skip null check
1616         Name name = TreeInfo.name(arg);
1617         if (name == names._this || name == names._super) return arg;
1618 
1619         int optag = JCTree.NULLCHK;
1620         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
1621         tree.operator = syms.nullcheck;
1622         tree.type = arg.type;
1623         return tree;
1624     }
1625 
1626     public void visitNewArray(JCNewArray tree) {
1627         Type owntype = types.createErrorType(tree.type);
1628         Type elemtype;
1629         if (tree.elemtype != null) {
1630             elemtype = attribType(tree.elemtype, env);
1631             chk.validate(tree.elemtype, env);
1632             owntype = elemtype;
1633             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1634                 attribExpr(l.head, env, syms.intType);
1635                 owntype = new ArrayType(owntype, syms.arrayClass);
1636             }
1637         } else {
1638             // we are seeing an untyped aggregate { ... }
1639             // this is allowed only if the prototype is an array
1640             if (pt.tag == ARRAY) {
1641                 elemtype = types.elemtype(pt);
1642             } else {
1643                 if (pt.tag != ERROR) {
1644                     log.error(tree.pos(), "illegal.initializer.for.type",
1645                               pt);
1646                 }
1647                 elemtype = types.createErrorType(pt);
1648             }
1649         }
1650         if (tree.elems != null) {
1651             attribExprs(tree.elems, env, elemtype);
1652             owntype = new ArrayType(elemtype, syms.arrayClass);
1653         }
1654         if (!types.isReifiable(elemtype))
1655             log.error(tree.pos(), "generic.array.creation");
1656         result = check(tree, owntype, VAL, pkind, pt);
1657     }
1658 
1659     public void visitParens(JCParens tree) {
1660         Type owntype = attribTree(tree.expr, env, pkind, pt);
1661         result = check(tree, owntype, pkind, pkind, pt);
1662         Symbol sym = TreeInfo.symbol(tree);
1663         if (sym != null && (sym.kind&(TYP|PCK)) != 0)
1664             log.error(tree.pos(), "illegal.start.of.type");
1665     }
1666 
1667     public void visitAssign(JCAssign tree) {
1668         Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
1669         Type capturedType = capture(owntype);
1670         attribExpr(tree.rhs, env, owntype);
1671         result = check(tree, capturedType, VAL, pkind, pt);
1672     }
1673 
1674     public void visitAssignop(JCAssignOp tree) {
1675         // Attribute arguments.
1676         Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
1677         Type operand = attribExpr(tree.rhs, env);
1678         // Find operator.
1679         Symbol operator = tree.operator = rs.resolveBinaryOperator(
1680             tree.pos(), tree.getTag() - JCTree.ASGOffset, env,
1681             owntype, operand);
1682 
1683         if (operator.kind == MTH) {
1684             chk.checkOperator(tree.pos(),
1685                               (OperatorSymbol)operator,
1686                               tree.getTag() - JCTree.ASGOffset,
1687                               owntype,
1688                               operand);
1689             chk.checkDivZero(tree.rhs.pos(), operator, operand);
1690             chk.checkCastable(tree.rhs.pos(),
1691                               operator.type.getReturnType(),
1692                               owntype);
1693         }
1694         result = check(tree, owntype, VAL, pkind, pt);
1695     }
1696 
1697     public void visitUnary(JCUnary tree) {
1698         // Attribute arguments.
1699         Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1700             ? attribTree(tree.arg, env, VAR, Type.noType)
1701             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
1702 
1703         // Find operator.
1704         Symbol operator = tree.operator =
1705             rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
1706 
1707         Type owntype = types.createErrorType(tree.type);
1708         if (operator.kind == MTH) {
1709             owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC)
1710                 ? tree.arg.type
1711                 : operator.type.getReturnType();
1712             int opc = ((OperatorSymbol)operator).opcode;
1713 
1714             // If the argument is constant, fold it.
1715             if (argtype.constValue() != null) {
1716                 Type ctype = cfolder.fold1(opc, argtype);
1717                 if (ctype != null) {
1718                     owntype = cfolder.coerce(ctype, owntype);
1719 
1720                     // Remove constant types from arguments to
1721                     // conserve space. The parser will fold concatenations
1722                     // of string literals; the code here also
1723                     // gets rid of intermediate results when some of the
1724                     // operands are constant identifiers.
1725                     if (tree.arg.type.tsym == syms.stringType.tsym) {
1726                         tree.arg.type = syms.stringType;
1727                     }
1728                 }
1729             }
1730         }
1731         result = check(tree, owntype, VAL, pkind, pt);
1732     }
1733 
1734     public void visitBinary(JCBinary tree) {
1735         // Attribute arguments.
1736         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
1737         Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
1738 
1739         // Find operator.
1740         Symbol operator = tree.operator =
1741             rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
1742 
1743         Type owntype = types.createErrorType(tree.type);
1744         if (operator.kind == MTH) {
1745             owntype = operator.type.getReturnType();
1746             int opc = chk.checkOperator(tree.lhs.pos(),
1747                                         (OperatorSymbol)operator,
1748                                         tree.getTag(),
1749                                         left,
1750                                         right);
1751 
1752             // If both arguments are constants, fold them.
1753             if (left.constValue() != null && right.constValue() != null) {
1754                 Type ctype = cfolder.fold2(opc, left, right);
1755                 if (ctype != null) {
1756                     owntype = cfolder.coerce(ctype, owntype);
1757 
1758                     // Remove constant types from arguments to
1759                     // conserve space. The parser will fold concatenations
1760                     // of string literals; the code here also
1761                     // gets rid of intermediate results when some of the
1762                     // operands are constant identifiers.
1763                     if (tree.lhs.type.tsym == syms.stringType.tsym) {
1764                         tree.lhs.type = syms.stringType;
1765                     }
1766                     if (tree.rhs.type.tsym == syms.stringType.tsym) {
1767                         tree.rhs.type = syms.stringType;
1768                     }
1769                 }
1770             }
1771 
1772             // Check that argument types of a reference ==, != are
1773             // castable to each other, (JLS???).
1774             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
1775                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
1776                     log.error(tree.pos(), "incomparable.types", left, right);
1777                 }
1778             }
1779 
1780             chk.checkDivZero(tree.rhs.pos(), operator, right);
1781         }
1782         result = check(tree, owntype, VAL, pkind, pt);
1783     }
1784 
1785     public void visitTypeCast(JCTypeCast tree) {
1786         Type clazztype = attribType(tree.clazz, env);
1787         chk.validate(tree.clazz, env);
1788         Type exprtype = attribExpr(tree.expr, env, Infer.anyPoly);
1789         Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1790         if (exprtype.constValue() != null)
1791             owntype = cfolder.coerce(exprtype, owntype);
1792         result = check(tree, capture(owntype), VAL, pkind, pt);
1793     }
1794 
1795     public void visitTypeTest(JCInstanceOf tree) {
1796         Type exprtype = chk.checkNullOrRefType(
1797             tree.expr.pos(), attribExpr(tree.expr, env));
1798         Type clazztype = chk.checkReifiableReferenceType(
1799             tree.clazz.pos(), attribType(tree.clazz, env));
1800         chk.validate(tree.clazz, env);
1801         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
1802         result = check(tree, syms.booleanType, VAL, pkind, pt);
1803     }
1804 
1805     public void visitIndexed(JCArrayAccess tree) {
1806         Type owntype = types.createErrorType(tree.type);
1807         Type atype = attribExpr(tree.indexed, env);
1808         attribExpr(tree.index, env, syms.intType);
1809         if (types.isArray(atype))
1810             owntype = types.elemtype(atype);
1811         else if (atype.tag != ERROR)
1812             log.error(tree.pos(), "array.req.but.found", atype);
1813         if ((pkind & VAR) == 0) owntype = capture(owntype);
1814         result = check(tree, owntype, VAR, pkind, pt);
1815     }
1816 
1817     public void visitIdent(JCIdent tree) {
1818         Symbol sym;
1819         boolean varArgs = false;
1820 
1821         // Find symbol
1822         if (pt.tag == METHOD || pt.tag == FORALL) {
1823             // If we are looking for a method, the prototype `pt' will be a
1824             // method type with the type of the call's arguments as parameters.
1825             env.info.varArgs = false;
1826             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments());
1827             varArgs = env.info.varArgs;
1828         } else if (tree.sym != null && tree.sym.kind != VAR) {
1829             sym = tree.sym;
1830         } else {
1831             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
1832         }
1833         tree.sym = sym;
1834 
1835         // (1) Also find the environment current for the class where
1836         //     sym is defined (`symEnv').
1837         // Only for pre-tiger versions (1.4 and earlier):
1838         // (2) Also determine whether we access symbol out of an anonymous
1839         //     class in a this or super call.  This is illegal for instance
1840         //     members since such classes don't carry a this$n link.
1841         //     (`noOuterThisPath').
1842         Env<AttrContext> symEnv = env;
1843         boolean noOuterThisPath = false;
1844         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
1845             (sym.kind & (VAR | MTH | TYP)) != 0 &&
1846             sym.owner.kind == TYP &&
1847             tree.name != names._this && tree.name != names._super) {
1848 
1849             // Find environment in which identifier is defined.
1850             while (symEnv.outer != null &&
1851                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
1852                 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
1853                     noOuterThisPath = !allowAnonOuterThis;
1854                 symEnv = symEnv.outer;
1855             }
1856         }
1857 
1858         // If symbol is a variable, ...
1859         if (sym.kind == VAR) {
1860             VarSymbol v = (VarSymbol)sym;
1861 
1862             // ..., evaluate its initializer, if it has one, and check for
1863             // illegal forward reference.
1864             checkInit(tree, env, v, false);
1865 
1866             // If symbol is a local variable accessed from an embedded
1867             // inner class check that it is final.
1868             if (v.owner.kind == MTH &&
1869                 v.owner != env.info.scope.owner &&
1870                 (v.flags_field & FINAL) == 0) {
1871                 log.error(tree.pos(),
1872                           "local.var.accessed.from.icls.needs.final",
1873                           v);
1874             }
1875 
1876             // If we are expecting a variable (as opposed to a value), check
1877             // that the variable is assignable in the current environment.
1878             if (pkind == VAR)
1879                 checkAssignable(tree.pos(), v, null, env);
1880         }
1881 
1882         // In a constructor body,
1883         // if symbol is a field or instance method, check that it is
1884         // not accessed before the supertype constructor is called.
1885         if ((symEnv.info.isSelfCall || noOuterThisPath) &&
1886             (sym.kind & (VAR | MTH)) != 0 &&
1887             sym.owner.kind == TYP &&
1888             (sym.flags() & STATIC) == 0) {
1889             chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
1890         }
1891         Env<AttrContext> env1 = env;
1892         if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
1893             // If the found symbol is inaccessible, then it is
1894             // accessed through an enclosing instance.  Locate this
1895             // enclosing instance:
1896             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
1897                 env1 = env1.outer;
1898         }
1899         result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs);
1900     }
1901 
1902     public void visitSelect(JCFieldAccess tree) {
1903         // Determine the expected kind of the qualifier expression.
1904         int skind = 0;
1905         if (tree.name == names._this || tree.name == names._super ||
1906             tree.name == names._class)
1907         {
1908             skind = TYP;
1909         } else {
1910             if ((pkind & PCK) != 0) skind = skind | PCK;
1911             if ((pkind & TYP) != 0) skind = skind | TYP | PCK;
1912             if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
1913         }
1914 
1915         // Attribute the qualifier expression, and determine its symbol (if any).
1916         Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
1917         if ((pkind & (PCK | TYP)) == 0)
1918             site = capture(site); // Capture field access
1919 
1920         // don't allow T.class T[].class, etc
1921         if (skind == TYP) {
1922             Type elt = site;
1923             while (elt.tag == ARRAY)
1924                 elt = ((ArrayType)elt).elemtype;
1925             if (elt.tag == TYPEVAR) {
1926                 log.error(tree.pos(), "type.var.cant.be.deref");
1927                 result = types.createErrorType(tree.type);
1928                 return;
1929             }
1930         }
1931 
1932         // If qualifier symbol is a type or `super', assert `selectSuper'
1933         // for the selection. This is relevant for determining whether
1934         // protected symbols are accessible.
1935         Symbol sitesym = TreeInfo.symbol(tree.selected);
1936         boolean selectSuperPrev = env.info.selectSuper;
1937         env.info.selectSuper =
1938             sitesym != null &&
1939             sitesym.name == names._super;
1940 
1941         // If selected expression is polymorphic, strip
1942         // type parameters and remember in env.info.tvars, so that
1943         // they can be added later (in Attr.checkId and Infer.instantiateMethod).
1944         if (tree.selected.type.tag == FORALL) {
1945             ForAll pstype = (ForAll)tree.selected.type;
1946             env.info.tvars = pstype.tvars;
1947             site = tree.selected.type = pstype.qtype;
1948         }
1949 
1950         // Determine the symbol represented by the selection.
1951         env.info.varArgs = false;
1952         Symbol sym = selectSym(tree, site, env, pt, pkind);
1953         if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
1954             site = capture(site);
1955             sym = selectSym(tree, site, env, pt, pkind);
1956         }
1957         boolean varArgs = env.info.varArgs;
1958         tree.sym = sym;
1959 
1960         if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) {
1961             while (site.tag == TYPEVAR) site = site.getUpperBound();
1962             site = capture(site);
1963         }
1964 
1965         // If that symbol is a variable, ...
1966         if (sym.kind == VAR) {
1967             VarSymbol v = (VarSymbol)sym;
1968 
1969             // ..., evaluate its initializer, if it has one, and check for
1970             // illegal forward reference.
1971             checkInit(tree, env, v, true);
1972 
1973             // If we are expecting a variable (as opposed to a value), check
1974             // that the variable is assignable in the current environment.
1975             if (pkind == VAR)
1976                 checkAssignable(tree.pos(), v, tree.selected, env);
1977         }
1978 
1979         // Disallow selecting a type from an expression
1980         if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
1981             tree.type = check(tree.selected, pt,
1982                               sitesym == null ? VAL : sitesym.kind, TYP|PCK, pt);
1983         }
1984 
1985         if (isType(sitesym)) {
1986             if (sym.name == names._this) {
1987                 // If `C' is the currently compiled class, check that
1988                 // C.this' does not appear in a call to a super(...)
1989                 if (env.info.isSelfCall &&
1990                     site.tsym == env.enclClass.sym) {
1991                     chk.earlyRefError(tree.pos(), sym);
1992                 }
1993             } else {
1994                 // Check if type-qualified fields or methods are static (JLS)
1995                 if ((sym.flags() & STATIC) == 0 &&
1996                     sym.name != names._super &&
1997                     (sym.kind == VAR || sym.kind == MTH)) {
1998                     rs.access(rs.new StaticError(sym),
1999                               tree.pos(), site, sym.name, true);
2000                 }
2001             }
2002         }
2003 
2004         // If we are selecting an instance member via a `super', ...
2005         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
2006 
2007             // Check that super-qualified symbols are not abstract (JLS)
2008             rs.checkNonAbstract(tree.pos(), sym);
2009 
2010             if (site.isRaw()) {
2011                 // Determine argument types for site.
2012                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
2013                 if (site1 != null) site = site1;
2014             }
2015         }
2016 
2017         env.info.selectSuper = selectSuperPrev;
2018         result = checkId(tree, site, sym, env, pkind, pt, varArgs);
2019         env.info.tvars = List.nil();
2020     }
2021     //where
2022         /** Determine symbol referenced by a Select expression,
2023          *
2024          *  @param tree   The select tree.
2025          *  @param site   The type of the selected expression,
2026          *  @param env    The current environment.
2027          *  @param pt     The current prototype.
2028          *  @param pkind  The expected kind(s) of the Select expression.
2029          */
2030         private Symbol selectSym(JCFieldAccess tree,
2031                                  Type site,
2032                                  Env<AttrContext> env,
2033                                  Type pt,
2034                                  int pkind) {
2035             DiagnosticPosition pos = tree.pos();
2036             Name name = tree.name;
2037 
2038             switch (site.tag) {
2039             case PACKAGE:
2040                 return rs.access(
2041                     rs.findIdentInPackage(env, site.tsym, name, pkind),
2042                     pos, site, name, true);
2043             case ARRAY:
2044             case CLASS:
2045                 if (pt.tag == METHOD || pt.tag == FORALL) {
2046                     return rs.resolveQualifiedMethod(
2047                         pos, env, site, name, pt.getParameterTypes(), pt.getTypeArguments());
2048                 } else if (name == names._this || name == names._super) {
2049                     return rs.resolveSelf(pos, env, site.tsym, name);
2050                 } else if (name == names._class) {
2051                     // In this case, we have already made sure in
2052                     // visitSelect that qualifier expression is a type.
2053                     Type t = syms.classType;
2054                     List<Type> typeargs = allowGenerics
2055                         ? List.of(types.erasure(site))
2056                         : List.<Type>nil();
2057                     t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
2058                     return new VarSymbol(
2059                         STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2060                 } else {
2061                     // We are seeing a plain identifier as selector.
2062                     Symbol sym = rs.findIdentInType(env, site, name, pkind);
2063                     if ((pkind & ERRONEOUS) == 0)
2064                         sym = rs.access(sym, pos, site, name, true);
2065                     return sym;
2066                 }
2067             case WILDCARD:
2068                 throw new AssertionError(tree);
2069             case TYPEVAR:
2070                 // Normally, site.getUpperBound() shouldn't be null.
2071                 // It should only happen during memberEnter/attribBase
2072                 // when determining the super type which *must* be
2073                 // done before attributing the type variables.  In
2074                 // other words, we are seeing this illegal program:
2075                 // class B<T> extends A<T.foo> {}
2076                 Symbol sym = (site.getUpperBound() != null)
2077                     ? selectSym(tree, capture(site.getUpperBound()), env, pt, pkind)
2078                     : null;
2079                 if (sym == null) {
2080                     log.error(pos, "type.var.cant.be.deref");
2081                     return syms.errSymbol;
2082                 } else {
2083                     Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
2084                         rs.new AccessError(env, site, sym) :
2085                                 sym;
2086                     rs.access(sym2, pos, site, name, true);
2087                     return sym;
2088                 }
2089             case ERROR:
2090                 // preserve identifier names through errors
2091                 return types.createErrorType(name, site.tsym, site).tsym;
2092             default:
2093                 // The qualifier expression is of a primitive type -- only
2094                 // .class is allowed for these.
2095                 if (name == names._class) {
2096                     // In this case, we have already made sure in Select that
2097                     // qualifier expression is a type.
2098                     Type t = syms.classType;
2099                     Type arg = types.boxedClass(site).type;
2100                     t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
2101                     return new VarSymbol(
2102                         STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
2103                 } else {
2104                     log.error(pos, "cant.deref", site);
2105                     return syms.errSymbol;
2106                 }
2107             }
2108         }
2109 
2110         /** Determine type of identifier or select expression and check that
2111          *  (1) the referenced symbol is not deprecated
2112          *  (2) the symbol's type is safe (@see checkSafe)
2113          *  (3) if symbol is a variable, check that its type and kind are
2114          *      compatible with the prototype and protokind.
2115          *  (4) if symbol is an instance field of a raw type,
2116          *      which is being assigned to, issue an unchecked warning if its
2117          *      type changes under erasure.
2118          *  (5) if symbol is an instance method of a raw type, issue an
2119          *      unchecked warning if its argument types change under erasure.
2120          *  If checks succeed:
2121          *    If symbol is a constant, return its constant type
2122          *    else if symbol is a method, return its result type
2123          *    otherwise return its type.
2124          *  Otherwise return errType.
2125          *
2126          *  @param tree       The syntax tree representing the identifier
2127          *  @param site       If this is a select, the type of the selected
2128          *                    expression, otherwise the type of the current class.
2129          *  @param sym        The symbol representing the identifier.
2130          *  @param env        The current environment.
2131          *  @param pkind      The set of expected kinds.
2132          *  @param pt         The expected type.
2133          */
2134         Type checkId(JCTree tree,
2135                      Type site,
2136                      Symbol sym,
2137                      Env<AttrContext> env,
2138                      int pkind,
2139                      Type pt,
2140                      boolean useVarargs) {
2141             if (pt.isErroneous()) return types.createErrorType(site);
2142             Type owntype; // The computed type of this identifier occurrence.
2143             switch (sym.kind) {
2144             case TYP:
2145                 // For types, the computed type equals the symbol's type,
2146                 // except for two situations:
2147                 owntype = sym.type;
2148                 if (owntype.tag == CLASS) {
2149                     Type ownOuter = owntype.getEnclosingType();
2150 
2151                     // (a) If the symbol's type is parameterized, erase it
2152                     // because no type parameters were given.
2153                     // We recover generic outer type later in visitTypeApply.
2154                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
2155                         owntype = types.erasure(owntype);
2156                     }
2157 
2158                     // (b) If the symbol's type is an inner class, then
2159                     // we have to interpret its outer type as a superclass
2160                     // of the site type. Example:
2161                     //
2162                     // class Tree<A> { class Visitor { ... } }
2163                     // class PointTree extends Tree<Point> { ... }
2164                     // ...PointTree.Visitor...
2165                     //
2166                     // Then the type of the last expression above is
2167                     // Tree<Point>.Visitor.
2168                     else if (ownOuter.tag == CLASS && site != ownOuter) {
2169                         Type normOuter = site;
2170                         if (normOuter.tag == CLASS)
2171                             normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
2172                         if (normOuter == null) // perhaps from an import
2173                             normOuter = types.erasure(ownOuter);
2174                         if (normOuter != ownOuter)
2175                             owntype = new ClassType(
2176                                 normOuter, List.<Type>nil(), owntype.tsym);
2177                     }
2178                 }
2179                 break;
2180             case VAR:
2181                 VarSymbol v = (VarSymbol)sym;
2182                 // Test (4): if symbol is an instance field of a raw type,
2183                 // which is being assigned to, issue an unchecked warning if
2184                 // its type changes under erasure.
2185                 if (allowGenerics &&
2186                     pkind == VAR &&
2187                     v.owner.kind == TYP &&
2188                     (v.flags() & STATIC) == 0 &&
2189                     (site.tag == CLASS || site.tag == TYPEVAR)) {
2190                     Type s = types.asOuterSuper(site, v.owner);
2191                     if (s != null &&
2192                         s.isRaw() &&
2193                         !types.isSameType(v.type, v.erasure(types))) {
2194                         chk.warnUnchecked(tree.pos(),
2195                                           "unchecked.assign.to.var",
2196                                           v, s);
2197                     }
2198                 }
2199                 // The computed type of a variable is the type of the
2200                 // variable symbol, taken as a member of the site type.
2201                 owntype = (sym.owner.kind == TYP &&
2202                            sym.name != names._this && sym.name != names._super)
2203                     ? types.memberType(site, sym)
2204                     : sym.type;
2205 
2206                 if (env.info.tvars.nonEmpty()) {
2207                     Type owntype1 = new ForAll(env.info.tvars, owntype);
2208                     for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
2209                         if (!owntype.contains(l.head)) {
2210                             log.error(tree.pos(), "undetermined.type", owntype1);
2211                             owntype1 = types.createErrorType(owntype1);
2212                         }
2213                     owntype = owntype1;
2214                 }
2215 
2216                 // If the variable is a constant, record constant value in
2217                 // computed type.
2218                 if (v.getConstValue() != null && isStaticReference(tree))
2219                     owntype = owntype.constType(v.getConstValue());
2220 
2221                 if (pkind == VAL) {
2222                     owntype = capture(owntype); // capture "names as expressions"
2223                 }
2224                 break;
2225             case MTH: {
2226                 JCMethodInvocation app = (JCMethodInvocation)env.tree;
2227                 owntype = checkMethod(site, sym, env, app.args,
2228                                       pt.getParameterTypes(), pt.getTypeArguments(),
2229                                       env.info.varArgs);
2230                 break;
2231             }
2232             case PCK: case ERR:
2233                 owntype = sym.type;
2234                 break;
2235             default:
2236                 throw new AssertionError("unexpected kind: " + sym.kind +
2237                                          " in tree " + tree);
2238             }
2239 
2240             // Test (1): emit a `deprecation' warning if symbol is deprecated.
2241             // (for constructors, the error was given when the constructor was
2242             // resolved)
2243             if (sym.name != names.init &&
2244                 (sym.flags() & DEPRECATED) != 0 &&
2245                 (env.info.scope.owner.flags() & DEPRECATED) == 0 &&
2246                 sym.outermostClass() != env.info.scope.owner.outermostClass())
2247                 chk.warnDeprecated(tree.pos(), sym);
2248 
2249             if ((sym.flags() & PROPRIETARY) != 0) {
2250                 if (enableSunApiLintControl)
2251                   chk.warnSunApi(tree.pos(), "sun.proprietary", sym);
2252                 else
2253                   log.strictWarning(tree.pos(), "sun.proprietary", sym);
2254             }
2255 
2256             // Test (3): if symbol is a variable, check that its type and
2257             // kind are compatible with the prototype and protokind.
2258             return check(tree, owntype, sym.kind, pkind, pt);
2259         }
2260 
2261         /** Check that variable is initialized and evaluate the variable's
2262          *  initializer, if not yet done. Also check that variable is not
2263          *  referenced before it is defined.
2264          *  @param tree    The tree making up the variable reference.
2265          *  @param env     The current environment.
2266          *  @param v       The variable's symbol.
2267          */
2268         private void checkInit(JCTree tree,
2269                                Env<AttrContext> env,
2270                                VarSymbol v,
2271                                boolean onlyWarning) {
2272 //          System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
2273 //                             tree.pos + " " + v.pos + " " +
2274 //                             Resolve.isStatic(env));//DEBUG
2275 
2276             // A forward reference is diagnosed if the declaration position
2277             // of the variable is greater than the current tree position
2278             // and the tree and variable definition occur in the same class
2279             // definition.  Note that writes don't count as references.
2280             // This check applies only to class and instance
2281             // variables.  Local variables follow different scope rules,
2282             // and are subject to definite assignment checking.
2283             if ((env.info.enclVar == v || v.pos > tree.pos) &&
2284                 v.owner.kind == TYP &&
2285                 canOwnInitializer(env.info.scope.owner) &&
2286                 v.owner == env.info.scope.owner.enclClass() &&
2287                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
2288                 (env.tree.getTag() != JCTree.ASSIGN ||
2289                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
2290                 String suffix = (env.info.enclVar == v) ?
2291                                 "self.ref" : "forward.ref";
2292                 if (!onlyWarning || isStaticEnumField(v)) {
2293                     log.error(tree.pos(), "illegal." + suffix);
2294                 } else if (useBeforeDeclarationWarning) {
2295                     log.warning(tree.pos(), suffix, v);
2296                 }
2297             }
2298 
2299             v.getConstValue(); // ensure initializer is evaluated
2300 
2301             checkEnumInitializer(tree, env, v);
2302         }
2303 
2304         /**
2305          * Check for illegal references to static members of enum.  In
2306          * an enum type, constructors and initializers may not
2307          * reference its static members unless they are constant.
2308          *
2309          * @param tree    The tree making up the variable reference.
2310          * @param env     The current environment.
2311          * @param v       The variable's symbol.
2312          * @see JLS 3rd Ed. (8.9 Enums)
2313          */
2314         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
2315             // JLS 3rd Ed.:
2316             //
2317             // "It is a compile-time error to reference a static field
2318             // of an enum type that is not a compile-time constant
2319             // (15.28) from constructors, instance initializer blocks,
2320             // or instance variable initializer expressions of that
2321             // type. It is a compile-time error for the constructors,
2322             // instance initializer blocks, or instance variable
2323             // initializer expressions of an enum constant e to refer
2324             // to itself or to an enum constant of the same type that
2325             // is declared to the right of e."
2326             if (isStaticEnumField(v)) {
2327                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
2328 
2329                 if (enclClass == null || enclClass.owner == null)
2330                     return;
2331 
2332                 // See if the enclosing class is the enum (or a
2333                 // subclass thereof) declaring v.  If not, this
2334                 // reference is OK.
2335                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
2336                     return;
2337 
2338                 // If the reference isn't from an initializer, then
2339                 // the reference is OK.
2340                 if (!Resolve.isInitializer(env))
2341                     return;
2342 
2343                 log.error(tree.pos(), "illegal.enum.static.ref");
2344             }
2345         }
2346 
2347         /** Is the given symbol a static, non-constant field of an Enum?
2348          *  Note: enum literals should not be regarded as such
2349          */
2350         private boolean isStaticEnumField(VarSymbol v) {
2351             return Flags.isEnum(v.owner) &&
2352                    Flags.isStatic(v) &&
2353                    !Flags.isConstant(v) &&
2354                    v.name != names._class;
2355         }
2356 
2357         /** Can the given symbol be the owner of code which forms part
2358          *  if class initialization? This is the case if the symbol is
2359          *  a type or field, or if the symbol is the synthetic method.
2360          *  owning a block.
2361          */
2362         private boolean canOwnInitializer(Symbol sym) {
2363             return
2364                 (sym.kind & (VAR | TYP)) != 0 ||
2365                 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
2366         }
2367 
2368     Warner noteWarner = new Warner();
2369 
2370     /**
2371      * Check that method arguments conform to its instantation.
2372      **/
2373     public Type checkMethod(Type site,
2374                             Symbol sym,
2375                             Env<AttrContext> env,
2376                             final List<JCExpression> argtrees,
2377                             List<Type> argtypes,
2378                             List<Type> typeargtypes,
2379                             boolean useVarargs) {
2380         // Test (5): if symbol is an instance method of a raw type, issue
2381         // an unchecked warning if its argument types change under erasure.
2382         if (allowGenerics &&
2383             (sym.flags() & STATIC) == 0 &&
2384             (site.tag == CLASS || site.tag == TYPEVAR)) {
2385             Type s = types.asOuterSuper(site, sym.owner);
2386             if (s != null && s.isRaw() &&
2387                 !types.isSameTypes(sym.type.getParameterTypes(),
2388                                    sym.erasure(types).getParameterTypes())) {
2389                 chk.warnUnchecked(env.tree.pos(),
2390                                   "unchecked.call.mbr.of.raw.type",
2391                                   sym, s);
2392             }
2393         }
2394 
2395         // Compute the identifier's instantiated type.
2396         // For methods, we need to compute the instance type by
2397         // Resolve.instantiate from the symbol's type as well as
2398         // any type arguments and value arguments.
2399         noteWarner.warned = false;
2400         Type owntype = rs.instantiate(env,
2401                                       site,
2402                                       sym,
2403                                       argtypes,
2404                                       typeargtypes,
2405                                       true,
2406                                       useVarargs,
2407                                       noteWarner);
2408         boolean warned = noteWarner.warned;
2409 
2410         // If this fails, something went wrong; we should not have
2411         // found the identifier in the first place.
2412         if (owntype == null) {
2413             if (!pt.isErroneous())
2414                 log.error(env.tree.pos(),
2415                           "internal.error.cant.instantiate",
2416                           sym, site,
2417                           Type.toString(pt.getParameterTypes()));
2418             owntype = types.createErrorType(site);
2419         } else {
2420             // System.out.println("call   : " + env.tree);
2421             // System.out.println("method : " + owntype);
2422             // System.out.println("actuals: " + argtypes);
2423             List<Type> formals = owntype.getParameterTypes();
2424             Type last = useVarargs ? formals.last() : null;
2425             if (sym.name==names.init &&
2426                 sym.owner == syms.enumSym)
2427                 formals = formals.tail.tail;
2428             List<JCExpression> args = argtrees;
2429             while (formals.head != last) {
2430                 JCTree arg = args.head;
2431                 Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head);
2432                 assertConvertible(arg, arg.type, formals.head, warn);
2433                 warned |= warn.warned;
2434                 args = args.tail;
2435                 formals = formals.tail;
2436             }
2437             if (useVarargs) {
2438                 Type varArg = types.elemtype(last);
2439                 while (args.tail != null) {
2440                     JCTree arg = args.head;
2441                     Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg);
2442                     assertConvertible(arg, arg.type, varArg, warn);
2443                     warned |= warn.warned;
2444                     args = args.tail;
2445                 }
2446             } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
2447                 // non-varargs call to varargs method
2448                 Type varParam = owntype.getParameterTypes().last();
2449                 Type lastArg = argtypes.last();
2450                 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
2451                     !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
2452                     log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
2453                                 types.elemtype(varParam),
2454                                 varParam);
2455             }
2456 
2457             if (warned && sym.type.tag == FORALL) {
2458                 chk.warnUnchecked(env.tree.pos(),
2459                                   "unchecked.meth.invocation.applied",
2460                                   kindName(sym),
2461                                   sym.name,
2462                                   rs.methodArguments(sym.type.getParameterTypes()),
2463                                   rs.methodArguments(argtypes),
2464                                   kindName(sym.location()),
2465                                   sym.location());
2466                 owntype = new MethodType(owntype.getParameterTypes(),
2467                                          types.erasure(owntype.getReturnType()),
2468                                          owntype.getThrownTypes(),
2469                                          syms.methodClass);
2470             }
2471             if (useVarargs) {
2472                 JCTree tree = env.tree;
2473                 Type argtype = owntype.getParameterTypes().last();
2474                 if (!types.isReifiable(argtype))
2475                     chk.warnUnchecked(env.tree.pos(),
2476                                       "unchecked.generic.array.creation",
2477                                       argtype);
2478                 Type elemtype = types.elemtype(argtype);
2479                 switch (tree.getTag()) {
2480                 case JCTree.APPLY:
2481                     ((JCMethodInvocation) tree).varargsElement = elemtype;
2482                     break;
2483                 case JCTree.NEWCLASS:
2484                     ((JCNewClass) tree).varargsElement = elemtype;
2485                     break;
2486                 default:
2487                     throw new AssertionError(""+tree);
2488                 }
2489             }
2490         }
2491         return owntype;
2492     }
2493 
2494     private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
2495         if (types.isConvertible(actual, formal, warn))
2496             return;
2497 
2498         if (formal.isCompound()
2499             && types.isSubtype(actual, types.supertype(formal))
2500             && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
2501             return;
2502 
2503         if (false) {
2504             // TODO: make assertConvertible work
2505             chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal);
2506             throw new AssertionError("Tree: " + tree
2507                                      + " actual:" + actual
2508                                      + " formal: " + formal);
2509         }
2510     }
2511 
2512     public void visitLiteral(JCLiteral tree) {
2513         result = check(
2514             tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt);
2515     }
2516     //where
2517     /** Return the type of a literal with given type tag.
2518      */
2519     Type litType(int tag) {
2520         return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
2521     }
2522 
2523     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
2524         result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
2525     }
2526 
2527     public void visitTypeArray(JCArrayTypeTree tree) {
2528         Type etype = attribType(tree.elemtype, env);
2529         Type type = new ArrayType(etype, syms.arrayClass);
2530         result = check(tree, type, TYP, pkind, pt);
2531     }
2532 
2533     /** Visitor method for parameterized types.
2534      *  Bound checking is left until later, since types are attributed
2535      *  before supertype structure is completely known
2536      */
2537     public void visitTypeApply(JCTypeApply tree) {
2538         Type owntype = types.createErrorType(tree.type);
2539 
2540         // Attribute functor part of application and make sure it's a class.
2541         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
2542 
2543         // Attribute type parameters
2544         List<Type> actuals = attribTypes(tree.arguments, env);
2545 
2546         if (clazztype.tag == CLASS) {
2547             List<Type> formals = clazztype.tsym.type.getTypeArguments();
2548 
2549             if (actuals.length() == formals.length() || actuals.isEmpty()) {
2550                 List<Type> a = actuals;
2551                 List<Type> f = formals;
2552                 while (a.nonEmpty()) {
2553                     a.head = a.head.withTypeVar(f.head);
2554                     a = a.tail;
2555                     f = f.tail;
2556                 }
2557                 // Compute the proper generic outer
2558                 Type clazzOuter = clazztype.getEnclosingType();
2559                 if (clazzOuter.tag == CLASS) {
2560                     Type site;
2561                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
2562                     if (clazz.getTag() == JCTree.IDENT) {
2563                         site = env.enclClass.sym.type;
2564                     } else if (clazz.getTag() == JCTree.SELECT) {
2565                         site = ((JCFieldAccess) clazz).selected.type;
2566                     } else throw new AssertionError(""+tree);
2567                     if (clazzOuter.tag == CLASS && site != clazzOuter) {
2568                         if (site.tag == CLASS)
2569                             site = types.asOuterSuper(site, clazzOuter.tsym);
2570                         if (site == null)
2571                             site = types.erasure(clazzOuter);
2572                         clazzOuter = site;
2573                     }
2574                 }
2575                 if (actuals.nonEmpty()) {
2576                     owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
2577                 }
2578                 else if (TreeInfo.isDiamond(tree)) {
2579                     //a type apply with no explicit type arguments - diamond operator
2580                     //the result type is a forall F where F's tvars are the type-variables
2581                     //that will be inferred when F is checked against the expected type
2582                     List<Type> ftvars = clazztype.tsym.type.getTypeArguments();
2583                     List<Type> new_tvars = types.newInstances(ftvars);
2584                     clazztype = new ClassType(clazzOuter, new_tvars, clazztype.tsym);
2585                     owntype = new ForAll(new_tvars, clazztype);
2586                 }
2587             } else {
2588                 if (formals.length() != 0) {
2589                     log.error(tree.pos(), "wrong.number.type.args",
2590                               Integer.toString(formals.length()));
2591                 } else {
2592                     log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
2593                 }
2594                 owntype = types.createErrorType(tree.type);
2595             }
2596         }
2597         result = check(tree, owntype, TYP, pkind, pt);
2598     }
2599 
2600     public void visitTypeParameter(JCTypeParameter tree) {
2601         TypeVar a = (TypeVar)tree.type;
2602         Set<Type> boundSet = new HashSet<Type>();
2603         if (a.bound.isErroneous())
2604             return;
2605         List<Type> bs = types.getBounds(a);
2606         if (tree.bounds.nonEmpty()) {
2607             // accept class or interface or typevar as first bound.
2608             Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false);
2609             boundSet.add(types.erasure(b));
2610             if (b.isErroneous()) {
2611                 a.bound = b;
2612             }
2613             else if (b.tag == TYPEVAR) {
2614                 // if first bound was a typevar, do not accept further bounds.
2615                 if (tree.bounds.tail.nonEmpty()) {
2616                     log.error(tree.bounds.tail.head.pos(),
2617                               "type.var.may.not.be.followed.by.other.bounds");
2618                     tree.bounds = List.of(tree.bounds.head);
2619                     a.bound = bs.head;
2620                 }
2621             } else {
2622                 // if first bound was a class or interface, accept only interfaces
2623                 // as further bounds.
2624                 for (JCExpression bound : tree.bounds.tail) {
2625                     bs = bs.tail;
2626                     Type i = checkBase(bs.head, bound, env, false, true, false);
2627                     if (i.isErroneous())
2628                         a.bound = i;
2629                     else if (i.tag == CLASS)
2630                         chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet);
2631                 }
2632             }
2633         }
2634         bs = types.getBounds(a);
2635 
2636         // in case of multiple bounds ...
2637         if (bs.length() > 1) {
2638             // ... the variable's bound is a class type flagged COMPOUND
2639             // (see comment for TypeVar.bound).
2640             // In this case, generate a class tree that represents the
2641             // bound class, ...
2642             JCTree extending;
2643             List<JCExpression> implementing;
2644             if ((bs.head.tsym.flags() & INTERFACE) == 0) {
2645                 extending = tree.bounds.head;
2646                 implementing = tree.bounds.tail;
2647             } else {
2648                 extending = null;
2649                 implementing = tree.bounds;
2650             }
2651             JCClassDecl cd = make.at(tree.pos).ClassDef(
2652                 make.Modifiers(PUBLIC | ABSTRACT),
2653                 tree.name, List.<JCTypeParameter>nil(),
2654                 extending, implementing, List.<JCTree>nil());
2655 
2656             ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
2657             assert (c.flags() & COMPOUND) != 0;
2658             cd.sym = c;
2659             c.sourcefile = env.toplevel.sourcefile;
2660 
2661             // ... and attribute the bound class
2662             c.flags_field |= UNATTRIBUTED;
2663             Env<AttrContext> cenv = enter.classEnv(cd, env);
2664             enter.typeEnvs.put(c, cenv);
2665         }
2666     }
2667 
2668 
2669     public void visitWildcard(JCWildcard tree) {
2670         //- System.err.println("visitWildcard("+tree+");");//DEBUG
2671         Type type = (tree.kind.kind == BoundKind.UNBOUND)
2672             ? syms.objectType
2673             : attribType(tree.inner, env);
2674         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
2675                                               tree.kind.kind,
2676                                               syms.boundClass),
2677                        TYP, pkind, pt);
2678     }
2679 
2680     public void visitAnnotation(JCAnnotation tree) {
2681         log.error(tree.pos(), "annotation.not.valid.for.type", pt);
2682         result = tree.type = syms.errType;
2683     }
2684 
2685     public void visitAnnotatedType(JCAnnotatedType tree) {
2686         result = tree.type = attribType(tree.getUnderlyingType(), env);
2687     }
2688 
2689     public void visitErroneous(JCErroneous tree) {
2690         if (tree.errs != null)
2691             for (JCTree err : tree.errs)
2692                 attribTree(err, env, ERR, pt);
2693         result = tree.type = syms.errType;
2694     }
2695 
2696     /** Default visitor method for all other trees.
2697      */
2698     public void visitTree(JCTree tree) {
2699         throw new AssertionError();
2700     }
2701 
2702     /** Main method: attribute class definition associated with given class symbol.
2703      *  reporting completion failures at the given position.
2704      *  @param pos The source position at which completion errors are to be
2705      *             reported.
2706      *  @param c   The class symbol whose definition will be attributed.
2707      */
2708     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
2709         try {
2710             annotate.flush();
2711             attribClass(c);
2712         } catch (CompletionFailure ex) {
2713             chk.completionError(pos, ex);
2714         }
2715     }
2716 
2717     /** Attribute class definition associated with given class symbol.
2718      *  @param c   The class symbol whose definition will be attributed.
2719      */
2720     void attribClass(ClassSymbol c) throws CompletionFailure {
2721         if (c.type.tag == ERROR) return;
2722 
2723         // Check for cycles in the inheritance graph, which can arise from
2724         // ill-formed class files.
2725         chk.checkNonCyclic(null, c.type);
2726 
2727         Type st = types.supertype(c.type);
2728         if ((c.flags_field & Flags.COMPOUND) == 0) {
2729             // First, attribute superclass.
2730             if (st.tag == CLASS)
2731                 attribClass((ClassSymbol)st.tsym);
2732 
2733             // Next attribute owner, if it is a class.
2734             if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
2735                 attribClass((ClassSymbol)c.owner);
2736         }
2737 
2738         // The previous operations might have attributed the current class
2739         // if there was a cycle. So we test first whether the class is still
2740         // UNATTRIBUTED.
2741         if ((c.flags_field & UNATTRIBUTED) != 0) {
2742             c.flags_field &= ~UNATTRIBUTED;
2743 
2744             // Get environment current at the point of class definition.
2745             Env<AttrContext> env = enter.typeEnvs.get(c);
2746 
2747             // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
2748             // because the annotations were not available at the time the env was created. Therefore,
2749             // we look up the environment chain for the first enclosing environment for which the
2750             // lint value is set. Typically, this is the parent env, but might be further if there
2751             // are any envs created as a result of TypeParameter nodes.
2752             Env<AttrContext> lintEnv = env;
2753             while (lintEnv.info.lint == null)
2754                 lintEnv = lintEnv.next;
2755 
2756             // Having found the enclosing lint value, we can initialize the lint value for this class
2757             env.info.lint = lintEnv.info.lint.augment(c.attributes_field, c.flags());
2758 
2759             Lint prevLint = chk.setLint(env.info.lint);
2760             JavaFileObject prev = log.useSource(c.sourcefile);
2761 
2762             try {
2763                 // java.lang.Enum may not be subclassed by a non-enum
2764                 if (st.tsym == syms.enumSym &&
2765                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
2766                     log.error(env.tree.pos(), "enum.no.subclassing");
2767 
2768                 // Enums may not be extended by source-level classes
2769                 if (st.tsym != null &&
2770                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
2771                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
2772                     !target.compilerBootstrap(c)) {
2773                     log.error(env.tree.pos(), "enum.types.not.extensible");
2774                 }
2775                 attribClassBody(env, c);
2776 
2777                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
2778             } finally {
2779                 log.useSource(prev);
2780                 chk.setLint(prevLint);
2781             }
2782 
2783         }
2784     }
2785 
2786     public void visitImport(JCImport tree) {
2787         // nothing to do
2788     }
2789 
2790     /** Finish the attribution of a class. */
2791     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
2792         JCClassDecl tree = (JCClassDecl)env.tree;
2793         assert c == tree.sym;
2794 
2795         // Validate annotations
2796         chk.validateAnnotations(tree.mods.annotations, c);
2797 
2798         // Validate type parameters, supertype and interfaces.
2799         attribBounds(tree.typarams);
2800         chk.validate(tree.typarams, env);
2801         chk.validate(tree.extending, env);
2802         chk.validate(tree.implementing, env);
2803 
2804         // If this is a non-abstract class, check that it has no abstract
2805         // methods or unimplemented methods of an implemented interface.
2806         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
2807             if (!relax)
2808                 chk.checkAllDefined(tree.pos(), c);
2809         }
2810 
2811         if ((c.flags() & ANNOTATION) != 0) {
2812             if (tree.implementing.nonEmpty())
2813                 log.error(tree.implementing.head.pos(),
2814                           "cant.extend.intf.annotation");
2815             if (tree.typarams.nonEmpty())
2816                 log.error(tree.typarams.head.pos(),
2817                           "intf.annotation.cant.have.type.params");
2818         } else {
2819             // Check that all extended classes and interfaces
2820             // are compatible (i.e. no two define methods with same arguments
2821             // yet different return types).  (JLS 8.4.6.3)
2822             chk.checkCompatibleSupertypes(tree.pos(), c.type);
2823         }
2824 
2825         // Check that class does not import the same parameterized interface
2826         // with two different argument lists.
2827         chk.checkClassBounds(tree.pos(), c.type);
2828 
2829         tree.type = c.type;
2830 
2831         boolean assertsEnabled = false;
2832         assert assertsEnabled = true;
2833         if (assertsEnabled) {
2834             for (List<JCTypeParameter> l = tree.typarams;
2835                  l.nonEmpty(); l = l.tail)
2836                 assert env.info.scope.lookup(l.head.name).scope != null;
2837         }
2838 
2839         // Check that a generic class doesn't extend Throwable
2840         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
2841             log.error(tree.extending.pos(), "generic.throwable");
2842 
2843         // Check that all methods which implement some
2844         // method conform to the method they implement.
2845         chk.checkImplementations(tree);
2846 
2847         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2848             // Attribute declaration
2849             attribStat(l.head, env);
2850             // Check that declarations in inner classes are not static (JLS 8.1.2)
2851             // Make an exception for static constants.
2852             if (c.owner.kind != PCK &&
2853                 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
2854                 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
2855                 Symbol sym = null;
2856                 if (l.head.getTag() == JCTree.VARDEF) sym = ((JCVariableDecl) l.head).sym;
2857                 if (sym == null ||
2858                     sym.kind != VAR ||
2859                     ((VarSymbol) sym).getConstValue() == null)
2860                     log.error(l.head.pos(), "icls.cant.have.static.decl");
2861             }
2862         }
2863 
2864         // Check for cycles among non-initial constructors.
2865         chk.checkCyclicConstructors(tree);
2866 
2867         // Check for cycles among annotation elements.
2868         chk.checkNonCyclicElements(tree);
2869 
2870         // Check for proper use of serialVersionUID
2871         if (env.info.lint.isEnabled(Lint.LintCategory.SERIAL) &&
2872             isSerializable(c) &&
2873             (c.flags() & Flags.ENUM) == 0 &&
2874             (c.flags() & ABSTRACT) == 0) {
2875             checkSerialVersionUID(tree, c);
2876         }
2877 
2878         // Check type annotations applicability rules
2879         validateTypeAnnotations(tree);
2880     }
2881         // where
2882         /** check if a class is a subtype of Serializable, if that is available. */
2883         private boolean isSerializable(ClassSymbol c) {
2884             try {
2885                 syms.serializableType.complete();
2886             }
2887             catch (CompletionFailure e) {
2888                 return false;
2889             }
2890             return types.isSubtype(c.type, syms.serializableType);
2891         }
2892 
2893         /** Check that an appropriate serialVersionUID member is defined. */
2894         private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
2895 
2896             // check for presence of serialVersionUID
2897             Scope.Entry e = c.members().lookup(names.serialVersionUID);
2898             while (e.scope != null && e.sym.kind != VAR) e = e.next();
2899             if (e.scope == null) {
2900                 log.warning(tree.pos(), "missing.SVUID", c);
2901                 return;
2902             }
2903 
2904             // check that it is static final
2905             VarSymbol svuid = (VarSymbol)e.sym;
2906             if ((svuid.flags() & (STATIC | FINAL)) !=
2907                 (STATIC | FINAL))
2908                 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
2909 
2910             // check that it is long
2911             else if (svuid.type.tag != TypeTags.LONG)
2912                 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
2913 
2914             // check constant
2915             else if (svuid.getConstValue() == null)
2916                 log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
2917         }
2918 
2919     private Type capture(Type type) {
2920         return types.capture(type);
2921     }
2922 
2923     private void validateTypeAnnotations(JCTree tree) {
2924         tree.accept(typeAnnotationsValidator);
2925     }
2926     //where
2927     private final JCTree.Visitor typeAnnotationsValidator =
2928         new TreeScanner() {
2929         public void visitAnnotation(JCAnnotation tree) {
2930             if (tree instanceof JCTypeAnnotation) {
2931                 chk.validateTypeAnnotation((JCTypeAnnotation)tree, false);
2932             }
2933             super.visitAnnotation(tree);
2934         }
2935         public void visitTypeParameter(JCTypeParameter tree) {
2936             chk.validateTypeAnnotations(tree.annotations, true);
2937             // don't call super. skip type annotations
2938             scan(tree.bounds);
2939         }
2940         public void visitMethodDef(JCMethodDecl tree) {
2941             // need to check static methods
2942             if ((tree.sym.flags() & Flags.STATIC) != 0) {
2943                 for (JCTypeAnnotation a : tree.receiverAnnotations) {
2944                     if (chk.isTypeAnnotation(a, false))
2945                         log.error(a.pos(), "annotation.type.not.applicable");
2946                 }
2947             }
2948             super.visitMethodDef(tree);
2949         }
2950     };
2951 }