src/share/classes/com/sun/tools/javac/comp/Attr.java

Fri, 10 May 2013 15:15:50 +0200

author
jlahoda
date
Fri, 10 May 2013 15:15:50 +0200
changeset 1734
8dd528992c15
parent 1697
950e8ac120f0
child 1755
ddb4a2bfcd82
permissions
-rw-r--r--

8012929: Trees.getElement should work not only for declaration trees, but also for use-trees
Reviewed-by: jjg
Contributed-by: Dusan Balek <dbalek@netbeans.org>, Jan Lahoda <jlahoda@netbeans.org>

     1 /*
     2  * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.  Oracle designates this
     8  * particular file as subject to the "Classpath" exception as provided
     9  * by Oracle in the LICENSE file that accompanied this code.
    10  *
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    14  * version 2 for more details (a copy is included in the LICENSE file that
    15  * accompanied this code).
    16  *
    17  * You should have received a copy of the GNU General Public License version
    18  * 2 along with this work; if not, write to the Free Software Foundation,
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    20  *
    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    22  * or visit www.oracle.com if you need additional information or have any
    23  * questions.
    24  */
    26 package com.sun.tools.javac.comp;
    28 import java.util.*;
    30 import javax.lang.model.element.ElementKind;
    31 import javax.lang.model.type.TypeKind;
    32 import javax.tools.JavaFileObject;
    34 import com.sun.source.tree.IdentifierTree;
    35 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
    36 import com.sun.source.tree.MemberSelectTree;
    37 import com.sun.source.tree.TreeVisitor;
    38 import com.sun.source.util.SimpleTreeVisitor;
    39 import com.sun.tools.javac.code.*;
    40 import com.sun.tools.javac.code.Lint.LintCategory;
    41 import com.sun.tools.javac.code.Symbol.*;
    42 import com.sun.tools.javac.code.Type.*;
    43 import com.sun.tools.javac.comp.Check.CheckContext;
    44 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
    45 import com.sun.tools.javac.comp.Infer.InferenceContext;
    46 import com.sun.tools.javac.comp.Infer.FreeTypeListener;
    47 import com.sun.tools.javac.jvm.*;
    48 import com.sun.tools.javac.tree.*;
    49 import com.sun.tools.javac.tree.JCTree.*;
    50 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
    51 import com.sun.tools.javac.util.*;
    52 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
    53 import com.sun.tools.javac.util.List;
    54 import static com.sun.tools.javac.code.Flags.*;
    55 import static com.sun.tools.javac.code.Flags.ANNOTATION;
    56 import static com.sun.tools.javac.code.Flags.BLOCK;
    57 import static com.sun.tools.javac.code.Kinds.*;
    58 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
    59 import static com.sun.tools.javac.code.TypeTag.*;
    60 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
    61 import static com.sun.tools.javac.tree.JCTree.Tag.*;
    63 /** This is the main context-dependent analysis phase in GJC. It
    64  *  encompasses name resolution, type checking and constant folding as
    65  *  subtasks. Some subtasks involve auxiliary classes.
    66  *  @see Check
    67  *  @see Resolve
    68  *  @see ConstFold
    69  *  @see Infer
    70  *
    71  *  <p><b>This is NOT part of any supported API.
    72  *  If you write code that depends on this, you do so at your own risk.
    73  *  This code and its internal interfaces are subject to change or
    74  *  deletion without notice.</b>
    75  */
    76 public class Attr extends JCTree.Visitor {
    77     protected static final Context.Key<Attr> attrKey =
    78         new Context.Key<Attr>();
    80     final Names names;
    81     final Log log;
    82     final Symtab syms;
    83     final Resolve rs;
    84     final Infer infer;
    85     final DeferredAttr deferredAttr;
    86     final Check chk;
    87     final Flow flow;
    88     final MemberEnter memberEnter;
    89     final TreeMaker make;
    90     final ConstFold cfolder;
    91     final Enter enter;
    92     final Target target;
    93     final Types types;
    94     final JCDiagnostic.Factory diags;
    95     final Annotate annotate;
    96     final DeferredLintHandler deferredLintHandler;
    98     public static Attr instance(Context context) {
    99         Attr instance = context.get(attrKey);
   100         if (instance == null)
   101             instance = new Attr(context);
   102         return instance;
   103     }
   105     protected Attr(Context context) {
   106         context.put(attrKey, this);
   108         names = Names.instance(context);
   109         log = Log.instance(context);
   110         syms = Symtab.instance(context);
   111         rs = Resolve.instance(context);
   112         chk = Check.instance(context);
   113         flow = Flow.instance(context);
   114         memberEnter = MemberEnter.instance(context);
   115         make = TreeMaker.instance(context);
   116         enter = Enter.instance(context);
   117         infer = Infer.instance(context);
   118         deferredAttr = DeferredAttr.instance(context);
   119         cfolder = ConstFold.instance(context);
   120         target = Target.instance(context);
   121         types = Types.instance(context);
   122         diags = JCDiagnostic.Factory.instance(context);
   123         annotate = Annotate.instance(context);
   124         deferredLintHandler = DeferredLintHandler.instance(context);
   126         Options options = Options.instance(context);
   128         Source source = Source.instance(context);
   129         allowGenerics = source.allowGenerics();
   130         allowVarargs = source.allowVarargs();
   131         allowEnums = source.allowEnums();
   132         allowBoxing = source.allowBoxing();
   133         allowCovariantReturns = source.allowCovariantReturns();
   134         allowAnonOuterThis = source.allowAnonOuterThis();
   135         allowStringsInSwitch = source.allowStringsInSwitch();
   136         allowPoly = source.allowPoly();
   137         allowLambda = source.allowLambda();
   138         allowDefaultMethods = source.allowDefaultMethods();
   139         sourceName = source.name;
   140         relax = (options.isSet("-retrofit") ||
   141                  options.isSet("-relax"));
   142         findDiamonds = options.get("findDiamond") != null &&
   143                  source.allowDiamond();
   144         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
   145         identifyLambdaCandidate = options.getBoolean("identifyLambdaCandidate", false);
   147         statInfo = new ResultInfo(NIL, Type.noType);
   148         varInfo = new ResultInfo(VAR, Type.noType);
   149         unknownExprInfo = new ResultInfo(VAL, Type.noType);
   150         unknownTypeInfo = new ResultInfo(TYP, Type.noType);
   151         unknownTypeExprInfo = new ResultInfo(Kinds.TYP | Kinds.VAL, Type.noType);
   152         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
   153     }
   155     /** Switch: relax some constraints for retrofit mode.
   156      */
   157     boolean relax;
   159     /** Switch: support target-typing inference
   160      */
   161     boolean allowPoly;
   163     /** Switch: support generics?
   164      */
   165     boolean allowGenerics;
   167     /** Switch: allow variable-arity methods.
   168      */
   169     boolean allowVarargs;
   171     /** Switch: support enums?
   172      */
   173     boolean allowEnums;
   175     /** Switch: support boxing and unboxing?
   176      */
   177     boolean allowBoxing;
   179     /** Switch: support covariant result types?
   180      */
   181     boolean allowCovariantReturns;
   183     /** Switch: support lambda expressions ?
   184      */
   185     boolean allowLambda;
   187     /** Switch: support default methods ?
   188      */
   189     boolean allowDefaultMethods;
   191     /** Switch: allow references to surrounding object from anonymous
   192      * objects during constructor call?
   193      */
   194     boolean allowAnonOuterThis;
   196     /** Switch: generates a warning if diamond can be safely applied
   197      *  to a given new expression
   198      */
   199     boolean findDiamonds;
   201     /**
   202      * Internally enables/disables diamond finder feature
   203      */
   204     static final boolean allowDiamondFinder = true;
   206     /**
   207      * Switch: warn about use of variable before declaration?
   208      * RFE: 6425594
   209      */
   210     boolean useBeforeDeclarationWarning;
   212     /**
   213      * Switch: generate warnings whenever an anonymous inner class that is convertible
   214      * to a lambda expression is found
   215      */
   216     boolean identifyLambdaCandidate;
   218     /**
   219      * Switch: allow strings in switch?
   220      */
   221     boolean allowStringsInSwitch;
   223     /**
   224      * Switch: name of source level; used for error reporting.
   225      */
   226     String sourceName;
   228     /** Check kind and type of given tree against protokind and prototype.
   229      *  If check succeeds, store type in tree and return it.
   230      *  If check fails, store errType in tree and return it.
   231      *  No checks are performed if the prototype is a method type.
   232      *  It is not necessary in this case since we know that kind and type
   233      *  are correct.
   234      *
   235      *  @param tree     The tree whose kind and type is checked
   236      *  @param ownkind  The computed kind of the tree
   237      *  @param resultInfo  The expected result of the tree
   238      */
   239     Type check(final JCTree tree, final Type found, final int ownkind, final ResultInfo resultInfo) {
   240         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
   241         Type owntype = found;
   242         if (!owntype.hasTag(ERROR) && !resultInfo.pt.hasTag(METHOD) && !resultInfo.pt.hasTag(FORALL)) {
   243             if (inferenceContext.free(found)) {
   244                 inferenceContext.addFreeTypeListener(List.of(found, resultInfo.pt), new FreeTypeListener() {
   245                     @Override
   246                     public void typesInferred(InferenceContext inferenceContext) {
   247                         ResultInfo pendingResult =
   248                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
   249                         check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
   250                     }
   251                 });
   252                 return tree.type = resultInfo.pt;
   253             } else {
   254                 if ((ownkind & ~resultInfo.pkind) == 0) {
   255                     owntype = resultInfo.check(tree, owntype);
   256                 } else {
   257                     log.error(tree.pos(), "unexpected.type",
   258                             kindNames(resultInfo.pkind),
   259                             kindName(ownkind));
   260                     owntype = types.createErrorType(owntype);
   261                 }
   262             }
   263         }
   264         tree.type = owntype;
   265         return owntype;
   266     }
   268     /** Is given blank final variable assignable, i.e. in a scope where it
   269      *  may be assigned to even though it is final?
   270      *  @param v      The blank final variable.
   271      *  @param env    The current environment.
   272      */
   273     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
   274         Symbol owner = owner(env);
   275            // owner refers to the innermost variable, method or
   276            // initializer block declaration at this point.
   277         return
   278             v.owner == owner
   279             ||
   280             ((owner.name == names.init ||    // i.e. we are in a constructor
   281               owner.kind == VAR ||           // i.e. we are in a variable initializer
   282               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
   283              &&
   284              v.owner == owner.owner
   285              &&
   286              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
   287     }
   289     /**
   290      * Return the innermost enclosing owner symbol in a given attribution context
   291      */
   292     Symbol owner(Env<AttrContext> env) {
   293         while (true) {
   294             switch (env.tree.getTag()) {
   295                 case VARDEF:
   296                     //a field can be owner
   297                     VarSymbol vsym = ((JCVariableDecl)env.tree).sym;
   298                     if (vsym.owner.kind == TYP) {
   299                         return vsym;
   300                     }
   301                     break;
   302                 case METHODDEF:
   303                     //method def is always an owner
   304                     return ((JCMethodDecl)env.tree).sym;
   305                 case CLASSDEF:
   306                     //class def is always an owner
   307                     return ((JCClassDecl)env.tree).sym;
   308                 case LAMBDA:
   309                     //a lambda is an owner - return a fresh synthetic method symbol
   310                     return new MethodSymbol(0, names.empty, null, syms.methodClass);
   311                 case BLOCK:
   312                     //static/instance init blocks are owner
   313                     Symbol blockSym = env.info.scope.owner;
   314                     if ((blockSym.flags() & BLOCK) != 0) {
   315                         return blockSym;
   316                     }
   317                     break;
   318                 case TOPLEVEL:
   319                     //toplevel is always an owner (for pkge decls)
   320                     return env.info.scope.owner;
   321             }
   322             Assert.checkNonNull(env.next);
   323             env = env.next;
   324         }
   325     }
   327     /** Check that variable can be assigned to.
   328      *  @param pos    The current source code position.
   329      *  @param v      The assigned varaible
   330      *  @param base   If the variable is referred to in a Select, the part
   331      *                to the left of the `.', null otherwise.
   332      *  @param env    The current environment.
   333      */
   334     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
   335         if ((v.flags() & FINAL) != 0 &&
   336             ((v.flags() & HASINIT) != 0
   337              ||
   338              !((base == null ||
   339                (base.hasTag(IDENT) && TreeInfo.name(base) == names._this)) &&
   340                isAssignableAsBlankFinal(v, env)))) {
   341             if (v.isResourceVariable()) { //TWR resource
   342                 log.error(pos, "try.resource.may.not.be.assigned", v);
   343             } else {
   344                 log.error(pos, "cant.assign.val.to.final.var", v);
   345             }
   346         }
   347     }
   349     /** Does tree represent a static reference to an identifier?
   350      *  It is assumed that tree is either a SELECT or an IDENT.
   351      *  We have to weed out selects from non-type names here.
   352      *  @param tree    The candidate tree.
   353      */
   354     boolean isStaticReference(JCTree tree) {
   355         if (tree.hasTag(SELECT)) {
   356             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
   357             if (lsym == null || lsym.kind != TYP) {
   358                 return false;
   359             }
   360         }
   361         return true;
   362     }
   364     /** Is this symbol a type?
   365      */
   366     static boolean isType(Symbol sym) {
   367         return sym != null && sym.kind == TYP;
   368     }
   370     /** The current `this' symbol.
   371      *  @param env    The current environment.
   372      */
   373     Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
   374         return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
   375     }
   377     /** Attribute a parsed identifier.
   378      * @param tree Parsed identifier name
   379      * @param topLevel The toplevel to use
   380      */
   381     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
   382         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
   383         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
   384                                            syms.errSymbol.name,
   385                                            null, null, null, null);
   386         localEnv.enclClass.sym = syms.errSymbol;
   387         return tree.accept(identAttributer, localEnv);
   388     }
   389     // where
   390         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
   391         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
   392             @Override
   393             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
   394                 Symbol site = visit(node.getExpression(), env);
   395                 if (site.kind == ERR)
   396                     return site;
   397                 Name name = (Name)node.getIdentifier();
   398                 if (site.kind == PCK) {
   399                     env.toplevel.packge = (PackageSymbol)site;
   400                     return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
   401                 } else {
   402                     env.enclClass.sym = (ClassSymbol)site;
   403                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
   404                 }
   405             }
   407             @Override
   408             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
   409                 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
   410             }
   411         }
   413     public Type coerce(Type etype, Type ttype) {
   414         return cfolder.coerce(etype, ttype);
   415     }
   417     public Type attribType(JCTree node, TypeSymbol sym) {
   418         Env<AttrContext> env = enter.typeEnvs.get(sym);
   419         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
   420         return attribTree(node, localEnv, unknownTypeInfo);
   421     }
   423     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
   424         // Attribute qualifying package or class.
   425         JCFieldAccess s = (JCFieldAccess)tree.qualid;
   426         return attribTree(s.selected,
   427                        env,
   428                        new ResultInfo(tree.staticImport ? TYP : (TYP | PCK),
   429                        Type.noType));
   430     }
   432     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
   433         breakTree = tree;
   434         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
   435         try {
   436             attribExpr(expr, env);
   437         } catch (BreakAttr b) {
   438             return b.env;
   439         } catch (AssertionError ae) {
   440             if (ae.getCause() instanceof BreakAttr) {
   441                 return ((BreakAttr)(ae.getCause())).env;
   442             } else {
   443                 throw ae;
   444             }
   445         } finally {
   446             breakTree = null;
   447             log.useSource(prev);
   448         }
   449         return env;
   450     }
   452     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
   453         breakTree = tree;
   454         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
   455         try {
   456             attribStat(stmt, env);
   457         } catch (BreakAttr b) {
   458             return b.env;
   459         } catch (AssertionError ae) {
   460             if (ae.getCause() instanceof BreakAttr) {
   461                 return ((BreakAttr)(ae.getCause())).env;
   462             } else {
   463                 throw ae;
   464             }
   465         } finally {
   466             breakTree = null;
   467             log.useSource(prev);
   468         }
   469         return env;
   470     }
   472     private JCTree breakTree = null;
   474     private static class BreakAttr extends RuntimeException {
   475         static final long serialVersionUID = -6924771130405446405L;
   476         private Env<AttrContext> env;
   477         private BreakAttr(Env<AttrContext> env) {
   478             this.env = copyEnv(env);
   479         }
   481         private Env<AttrContext> copyEnv(Env<AttrContext> env) {
   482             Env<AttrContext> newEnv =
   483                     env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
   484             if (newEnv.outer != null) {
   485                 newEnv.outer = copyEnv(newEnv.outer);
   486             }
   487             return newEnv;
   488         }
   490         private Scope copyScope(Scope sc) {
   491             Scope newScope = new Scope(sc.owner);
   492             List<Symbol> elemsList = List.nil();
   493             while (sc != null) {
   494                 for (Scope.Entry e = sc.elems ; e != null ; e = e.sibling) {
   495                     elemsList = elemsList.prepend(e.sym);
   496                 }
   497                 sc = sc.next;
   498             }
   499             for (Symbol s : elemsList) {
   500                 newScope.enter(s);
   501             }
   502             return newScope;
   503         }
   504     }
   506     class ResultInfo {
   507         final int pkind;
   508         final Type pt;
   509         final CheckContext checkContext;
   511         ResultInfo(int pkind, Type pt) {
   512             this(pkind, pt, chk.basicHandler);
   513         }
   515         protected ResultInfo(int pkind, Type pt, CheckContext checkContext) {
   516             this.pkind = pkind;
   517             this.pt = pt;
   518             this.checkContext = checkContext;
   519         }
   521         protected Type check(final DiagnosticPosition pos, final Type found) {
   522             return chk.checkType(pos, found, pt, checkContext);
   523         }
   525         protected ResultInfo dup(Type newPt) {
   526             return new ResultInfo(pkind, newPt, checkContext);
   527         }
   529         protected ResultInfo dup(CheckContext newContext) {
   530             return new ResultInfo(pkind, pt, newContext);
   531         }
   532     }
   534     class RecoveryInfo extends ResultInfo {
   536         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
   537             super(Kinds.VAL, Type.recoveryType, new Check.NestedCheckContext(chk.basicHandler) {
   538                 @Override
   539                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
   540                     return deferredAttrContext;
   541                 }
   542                 @Override
   543                 public boolean compatible(Type found, Type req, Warner warn) {
   544                     return true;
   545                 }
   546                 @Override
   547                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
   548                     chk.basicHandler.report(pos, details);
   549                 }
   550             });
   551         }
   553         @Override
   554         protected Type check(DiagnosticPosition pos, Type found) {
   555             return chk.checkNonVoid(pos, super.check(pos, found));
   556         }
   557     }
   559     final ResultInfo statInfo;
   560     final ResultInfo varInfo;
   561     final ResultInfo unknownExprInfo;
   562     final ResultInfo unknownTypeInfo;
   563     final ResultInfo unknownTypeExprInfo;
   564     final ResultInfo recoveryInfo;
   566     Type pt() {
   567         return resultInfo.pt;
   568     }
   570     int pkind() {
   571         return resultInfo.pkind;
   572     }
   574 /* ************************************************************************
   575  * Visitor methods
   576  *************************************************************************/
   578     /** Visitor argument: the current environment.
   579      */
   580     Env<AttrContext> env;
   582     /** Visitor argument: the currently expected attribution result.
   583      */
   584     ResultInfo resultInfo;
   586     /** Visitor result: the computed type.
   587      */
   588     Type result;
   590     /** Visitor method: attribute a tree, catching any completion failure
   591      *  exceptions. Return the tree's type.
   592      *
   593      *  @param tree    The tree to be visited.
   594      *  @param env     The environment visitor argument.
   595      *  @param resultInfo   The result info visitor argument.
   596      */
   597     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
   598         Env<AttrContext> prevEnv = this.env;
   599         ResultInfo prevResult = this.resultInfo;
   600         try {
   601             this.env = env;
   602             this.resultInfo = resultInfo;
   603             tree.accept(this);
   604             if (tree == breakTree &&
   605                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
   606                 throw new BreakAttr(env);
   607             }
   608             return result;
   609         } catch (CompletionFailure ex) {
   610             tree.type = syms.errType;
   611             return chk.completionError(tree.pos(), ex);
   612         } finally {
   613             this.env = prevEnv;
   614             this.resultInfo = prevResult;
   615         }
   616     }
   618     /** Derived visitor method: attribute an expression tree.
   619      */
   620     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
   621         return attribTree(tree, env, new ResultInfo(VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
   622     }
   624     /** Derived visitor method: attribute an expression tree with
   625      *  no constraints on the computed type.
   626      */
   627     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
   628         return attribTree(tree, env, unknownExprInfo);
   629     }
   631     /** Derived visitor method: attribute a type tree.
   632      */
   633     public Type attribType(JCTree tree, Env<AttrContext> env) {
   634         Type result = attribType(tree, env, Type.noType);
   635         return result;
   636     }
   638     /** Derived visitor method: attribute a type tree.
   639      */
   640     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
   641         Type result = attribTree(tree, env, new ResultInfo(TYP, pt));
   642         return result;
   643     }
   645     /** Derived visitor method: attribute a statement or definition tree.
   646      */
   647     public Type attribStat(JCTree tree, Env<AttrContext> env) {
   648         return attribTree(tree, env, statInfo);
   649     }
   651     /** Attribute a list of expressions, returning a list of types.
   652      */
   653     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
   654         ListBuffer<Type> ts = new ListBuffer<Type>();
   655         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
   656             ts.append(attribExpr(l.head, env, pt));
   657         return ts.toList();
   658     }
   660     /** Attribute a list of statements, returning nothing.
   661      */
   662     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
   663         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
   664             attribStat(l.head, env);
   665     }
   667     /** Attribute the arguments in a method call, returning a list of types.
   668      */
   669     List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
   670         ListBuffer<Type> argtypes = new ListBuffer<Type>();
   671         for (JCExpression arg : trees) {
   672             Type argtype = allowPoly && deferredAttr.isDeferred(env, arg) ?
   673                     deferredAttr.new DeferredType(arg, env) :
   674                     chk.checkNonVoid(arg, attribExpr(arg, env, Infer.anyPoly));
   675             argtypes.append(argtype);
   676         }
   677         return argtypes.toList();
   678     }
   680     /** Attribute a type argument list, returning a list of types.
   681      *  Caller is responsible for calling checkRefTypes.
   682      */
   683     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
   684         ListBuffer<Type> argtypes = new ListBuffer<Type>();
   685         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
   686             argtypes.append(attribType(l.head, env));
   687         return argtypes.toList();
   688     }
   690     /** Attribute a type argument list, returning a list of types.
   691      *  Check that all the types are references.
   692      */
   693     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
   694         List<Type> types = attribAnyTypes(trees, env);
   695         return chk.checkRefTypes(trees, types);
   696     }
   698     /**
   699      * Attribute type variables (of generic classes or methods).
   700      * Compound types are attributed later in attribBounds.
   701      * @param typarams the type variables to enter
   702      * @param env      the current environment
   703      */
   704     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
   705         for (JCTypeParameter tvar : typarams) {
   706             TypeVar a = (TypeVar)tvar.type;
   707             a.tsym.flags_field |= UNATTRIBUTED;
   708             a.bound = Type.noType;
   709             if (!tvar.bounds.isEmpty()) {
   710                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
   711                 for (JCExpression bound : tvar.bounds.tail)
   712                     bounds = bounds.prepend(attribType(bound, env));
   713                 types.setBounds(a, bounds.reverse());
   714             } else {
   715                 // if no bounds are given, assume a single bound of
   716                 // java.lang.Object.
   717                 types.setBounds(a, List.of(syms.objectType));
   718             }
   719             a.tsym.flags_field &= ~UNATTRIBUTED;
   720         }
   721         for (JCTypeParameter tvar : typarams) {
   722             chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
   723         }
   724     }
   726     /**
   727      * Attribute the type references in a list of annotations.
   728      */
   729     void attribAnnotationTypes(List<JCAnnotation> annotations,
   730                                Env<AttrContext> env) {
   731         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
   732             JCAnnotation a = al.head;
   733             attribType(a.annotationType, env);
   734         }
   735     }
   737     /**
   738      * Attribute a "lazy constant value".
   739      *  @param env         The env for the const value
   740      *  @param initializer The initializer for the const value
   741      *  @param type        The expected type, or null
   742      *  @see VarSymbol#setLazyConstValue
   743      */
   744     public Object attribLazyConstantValue(Env<AttrContext> env,
   745                                       JCTree.JCExpression initializer,
   746                                       Type type) {
   748         // in case no lint value has been set up for this env, scan up
   749         // env stack looking for smallest enclosing env for which it is set.
   750         Env<AttrContext> lintEnv = env;
   751         while (lintEnv.info.lint == null)
   752             lintEnv = lintEnv.next;
   754         // Having found the enclosing lint value, we can initialize the lint value for this class
   755         // ... but ...
   756         // There's a problem with evaluating annotations in the right order, such that
   757         // env.info.enclVar.attributes_field might not yet have been evaluated, and so might be
   758         // null. In that case, calling augment will throw an NPE. To avoid this, for now we
   759         // revert to the jdk 6 behavior and ignore the (unevaluated) attributes.
   760         if (env.info.enclVar.annotations.pendingCompletion()) {
   761             env.info.lint = lintEnv.info.lint;
   762         } else {
   763             env.info.lint = lintEnv.info.lint.augment(env.info.enclVar.annotations,
   764                                                       env.info.enclVar.flags());
   765         }
   767         Lint prevLint = chk.setLint(env.info.lint);
   768         JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
   770         try {
   771             memberEnter.typeAnnotate(initializer, env, env.info.enclVar);
   772             annotate.flush();
   773             Type itype = attribExpr(initializer, env, type);
   774             if (itype.constValue() != null)
   775                 return coerce(itype, type).constValue();
   776             else
   777                 return null;
   778         } finally {
   779             env.info.lint = prevLint;
   780             log.useSource(prevSource);
   781         }
   782     }
   784     /** Attribute type reference in an `extends' or `implements' clause.
   785      *  Supertypes of anonymous inner classes are usually already attributed.
   786      *
   787      *  @param tree              The tree making up the type reference.
   788      *  @param env               The environment current at the reference.
   789      *  @param classExpected     true if only a class is expected here.
   790      *  @param interfaceExpected true if only an interface is expected here.
   791      */
   792     Type attribBase(JCTree tree,
   793                     Env<AttrContext> env,
   794                     boolean classExpected,
   795                     boolean interfaceExpected,
   796                     boolean checkExtensible) {
   797         Type t = tree.type != null ?
   798             tree.type :
   799             attribType(tree, env);
   800         return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
   801     }
   802     Type checkBase(Type t,
   803                    JCTree tree,
   804                    Env<AttrContext> env,
   805                    boolean classExpected,
   806                    boolean interfaceExpected,
   807                    boolean checkExtensible) {
   808         if (t.isErroneous())
   809             return t;
   810         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
   811             // check that type variable is already visible
   812             if (t.getUpperBound() == null) {
   813                 log.error(tree.pos(), "illegal.forward.ref");
   814                 return types.createErrorType(t);
   815             }
   816         } else {
   817             t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
   818         }
   819         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
   820             log.error(tree.pos(), "intf.expected.here");
   821             // return errType is necessary since otherwise there might
   822             // be undetected cycles which cause attribution to loop
   823             return types.createErrorType(t);
   824         } else if (checkExtensible &&
   825                    classExpected &&
   826                    (t.tsym.flags() & INTERFACE) != 0) {
   827                 log.error(tree.pos(), "no.intf.expected.here");
   828             return types.createErrorType(t);
   829         }
   830         if (checkExtensible &&
   831             ((t.tsym.flags() & FINAL) != 0)) {
   832             log.error(tree.pos(),
   833                       "cant.inherit.from.final", t.tsym);
   834         }
   835         chk.checkNonCyclic(tree.pos(), t);
   836         return t;
   837     }
   839     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
   840         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
   841         id.type = env.info.scope.owner.type;
   842         id.sym = env.info.scope.owner;
   843         return id.type;
   844     }
   846     public void visitClassDef(JCClassDecl tree) {
   847         // Local classes have not been entered yet, so we need to do it now:
   848         if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
   849             enter.classEnter(tree, env);
   851         ClassSymbol c = tree.sym;
   852         if (c == null) {
   853             // exit in case something drastic went wrong during enter.
   854             result = null;
   855         } else {
   856             // make sure class has been completed:
   857             c.complete();
   859             // If this class appears as an anonymous class
   860             // in a superclass constructor call where
   861             // no explicit outer instance is given,
   862             // disable implicit outer instance from being passed.
   863             // (This would be an illegal access to "this before super").
   864             if (env.info.isSelfCall &&
   865                 env.tree.hasTag(NEWCLASS) &&
   866                 ((JCNewClass) env.tree).encl == null)
   867             {
   868                 c.flags_field |= NOOUTERTHIS;
   869             }
   870             attribClass(tree.pos(), c);
   871             result = tree.type = c.type;
   872         }
   873     }
   875     public void visitMethodDef(JCMethodDecl tree) {
   876         MethodSymbol m = tree.sym;
   877         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
   879         Lint lint = env.info.lint.augment(m.annotations, m.flags());
   880         Lint prevLint = chk.setLint(lint);
   881         MethodSymbol prevMethod = chk.setMethod(m);
   882         try {
   883             deferredLintHandler.flush(tree.pos());
   884             chk.checkDeprecatedAnnotation(tree.pos(), m);
   887             // Create a new environment with local scope
   888             // for attributing the method.
   889             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
   890             localEnv.info.lint = lint;
   892             attribStats(tree.typarams, localEnv);
   894             // If we override any other methods, check that we do so properly.
   895             // JLS ???
   896             if (m.isStatic()) {
   897                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
   898             } else {
   899                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
   900             }
   901             chk.checkOverride(tree, m);
   903             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
   904                 log.error(tree, "default.overrides.object.member", m.name, Kinds.kindName(m.location()), m.location());
   905             }
   907             // Enter all type parameters into the local method scope.
   908             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
   909                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
   911             ClassSymbol owner = env.enclClass.sym;
   912             if ((owner.flags() & ANNOTATION) != 0 &&
   913                 tree.params.nonEmpty())
   914                 log.error(tree.params.head.pos(),
   915                           "intf.annotation.members.cant.have.params");
   917             // Attribute all value parameters.
   918             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
   919                 attribStat(l.head, localEnv);
   920             }
   922             chk.checkVarargsMethodDecl(localEnv, tree);
   924             // Check that type parameters are well-formed.
   925             chk.validate(tree.typarams, localEnv);
   927             // Check that result type is well-formed.
   928             chk.validate(tree.restype, localEnv);
   930             // Check that receiver type is well-formed.
   931             if (tree.recvparam != null) {
   932                 // Use a new environment to check the receiver parameter.
   933                 // Otherwise I get "might not have been initialized" errors.
   934                 // Is there a better way?
   935                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
   936                 attribType(tree.recvparam, newEnv);
   937                 chk.validate(tree.recvparam, newEnv);
   938                 if (!(tree.recvparam.type == m.owner.type || types.isSameType(tree.recvparam.type, m.owner.type))) {
   939                     // The == covers the common non-generic case, but for generic classes we need isSameType;
   940                     // note that equals didn't work.
   941                     log.error(tree.recvparam.pos(), "incorrect.receiver.type");
   942                 }
   943             }
   945             // annotation method checks
   946             if ((owner.flags() & ANNOTATION) != 0) {
   947                 // annotation method cannot have throws clause
   948                 if (tree.thrown.nonEmpty()) {
   949                     log.error(tree.thrown.head.pos(),
   950                             "throws.not.allowed.in.intf.annotation");
   951                 }
   952                 // annotation method cannot declare type-parameters
   953                 if (tree.typarams.nonEmpty()) {
   954                     log.error(tree.typarams.head.pos(),
   955                             "intf.annotation.members.cant.have.type.params");
   956                 }
   957                 // validate annotation method's return type (could be an annotation type)
   958                 chk.validateAnnotationType(tree.restype);
   959                 // ensure that annotation method does not clash with members of Object/Annotation
   960                 chk.validateAnnotationMethod(tree.pos(), m);
   962                 if (tree.defaultValue != null) {
   963                     // if default value is an annotation, check it is a well-formed
   964                     // annotation value (e.g. no duplicate values, no missing values, etc.)
   965                     chk.validateAnnotationTree(tree.defaultValue);
   966                 }
   967             }
   969             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
   970                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
   972             if (tree.body == null) {
   973                 // Empty bodies are only allowed for
   974                 // abstract, native, or interface methods, or for methods
   975                 // in a retrofit signature class.
   976                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0 &&
   977                     !relax)
   978                     log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
   979                 if (tree.defaultValue != null) {
   980                     if ((owner.flags() & ANNOTATION) == 0)
   981                         log.error(tree.pos(),
   982                                   "default.allowed.in.intf.annotation.member");
   983                 }
   984             } else if ((tree.sym.flags() & ABSTRACT) != 0 && !isDefaultMethod) {
   985                 if ((owner.flags() & INTERFACE) != 0) {
   986                     log.error(tree.body.pos(), "intf.meth.cant.have.body");
   987                 } else {
   988                     log.error(tree.pos(), "abstract.meth.cant.have.body");
   989                 }
   990             } else if ((tree.mods.flags & NATIVE) != 0) {
   991                 log.error(tree.pos(), "native.meth.cant.have.body");
   992             } else {
   993                 // Add an implicit super() call unless an explicit call to
   994                 // super(...) or this(...) is given
   995                 // or we are compiling class java.lang.Object.
   996                 if (tree.name == names.init && owner.type != syms.objectType) {
   997                     JCBlock body = tree.body;
   998                     if (body.stats.isEmpty() ||
   999                         !TreeInfo.isSelfCall(body.stats.head)) {
  1000                         body.stats = body.stats.
  1001                             prepend(memberEnter.SuperCall(make.at(body.pos),
  1002                                                           List.<Type>nil(),
  1003                                                           List.<JCVariableDecl>nil(),
  1004                                                           false));
  1005                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
  1006                                (tree.mods.flags & GENERATEDCONSTR) == 0 &&
  1007                                TreeInfo.isSuperCall(body.stats.head)) {
  1008                         // enum constructors are not allowed to call super
  1009                         // directly, so make sure there aren't any super calls
  1010                         // in enum constructors, except in the compiler
  1011                         // generated one.
  1012                         log.error(tree.body.stats.head.pos(),
  1013                                   "call.to.super.not.allowed.in.enum.ctor",
  1014                                   env.enclClass.sym);
  1018                 // Attribute all type annotations in the body
  1019                 memberEnter.typeAnnotate(tree.body, localEnv, m);
  1020                 annotate.flush();
  1022                 // Attribute method body.
  1023                 attribStat(tree.body, localEnv);
  1026             localEnv.info.scope.leave();
  1027             result = tree.type = m.type;
  1028             chk.validateAnnotations(tree.mods.annotations, m);
  1030         finally {
  1031             chk.setLint(prevLint);
  1032             chk.setMethod(prevMethod);
  1036     public void visitVarDef(JCVariableDecl tree) {
  1037         // Local variables have not been entered yet, so we need to do it now:
  1038         if (env.info.scope.owner.kind == MTH) {
  1039             if (tree.sym != null) {
  1040                 // parameters have already been entered
  1041                 env.info.scope.enter(tree.sym);
  1042             } else {
  1043                 memberEnter.memberEnter(tree, env);
  1044                 annotate.flush();
  1046         } else {
  1047             if (tree.init != null) {
  1048                 // Field initializer expression need to be entered.
  1049                 memberEnter.typeAnnotate(tree.init, env, tree.sym);
  1050                 annotate.flush();
  1054         VarSymbol v = tree.sym;
  1055         Lint lint = env.info.lint.augment(v.annotations, v.flags());
  1056         Lint prevLint = chk.setLint(lint);
  1058         // Check that the variable's declared type is well-formed.
  1059         chk.validate(tree.vartype, env);
  1060         deferredLintHandler.flush(tree.pos());
  1062         try {
  1063             chk.checkDeprecatedAnnotation(tree.pos(), v);
  1065             if (tree.init != null) {
  1066                 if ((v.flags_field & FINAL) != 0 &&
  1067                         !tree.init.hasTag(NEWCLASS) &&
  1068                         !tree.init.hasTag(LAMBDA) &&
  1069                         !tree.init.hasTag(REFERENCE)) {
  1070                     // In this case, `v' is final.  Ensure that it's initializer is
  1071                     // evaluated.
  1072                     v.getConstValue(); // ensure initializer is evaluated
  1073                 } else {
  1074                     // Attribute initializer in a new environment
  1075                     // with the declared variable as owner.
  1076                     // Check that initializer conforms to variable's declared type.
  1077                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
  1078                     initEnv.info.lint = lint;
  1079                     // In order to catch self-references, we set the variable's
  1080                     // declaration position to maximal possible value, effectively
  1081                     // marking the variable as undefined.
  1082                     initEnv.info.enclVar = v;
  1083                     attribExpr(tree.init, initEnv, v.type);
  1086             result = tree.type = v.type;
  1087             chk.validateAnnotations(tree.mods.annotations, v);
  1089         finally {
  1090             chk.setLint(prevLint);
  1094     public void visitSkip(JCSkip tree) {
  1095         result = null;
  1098     public void visitBlock(JCBlock tree) {
  1099         if (env.info.scope.owner.kind == TYP) {
  1100             // Block is a static or instance initializer;
  1101             // let the owner of the environment be a freshly
  1102             // created BLOCK-method.
  1103             Env<AttrContext> localEnv =
  1104                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
  1105             localEnv.info.scope.owner =
  1106                 new MethodSymbol(tree.flags | BLOCK |
  1107                     env.info.scope.owner.flags() & STRICTFP, names.empty, null,
  1108                     env.info.scope.owner);
  1109             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
  1111             // Attribute all type annotations in the block
  1112             memberEnter.typeAnnotate(tree, localEnv, localEnv.info.scope.owner);
  1113             annotate.flush();
  1115             attribStats(tree.stats, localEnv);
  1116         } else {
  1117             // Create a new local environment with a local scope.
  1118             Env<AttrContext> localEnv =
  1119                 env.dup(tree, env.info.dup(env.info.scope.dup()));
  1120             try {
  1121                 attribStats(tree.stats, localEnv);
  1122             } finally {
  1123                 localEnv.info.scope.leave();
  1126         result = null;
  1129     public void visitDoLoop(JCDoWhileLoop tree) {
  1130         attribStat(tree.body, env.dup(tree));
  1131         attribExpr(tree.cond, env, syms.booleanType);
  1132         result = null;
  1135     public void visitWhileLoop(JCWhileLoop tree) {
  1136         attribExpr(tree.cond, env, syms.booleanType);
  1137         attribStat(tree.body, env.dup(tree));
  1138         result = null;
  1141     public void visitForLoop(JCForLoop tree) {
  1142         Env<AttrContext> loopEnv =
  1143             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
  1144         try {
  1145             attribStats(tree.init, loopEnv);
  1146             if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
  1147             loopEnv.tree = tree; // before, we were not in loop!
  1148             attribStats(tree.step, loopEnv);
  1149             attribStat(tree.body, loopEnv);
  1150             result = null;
  1152         finally {
  1153             loopEnv.info.scope.leave();
  1157     public void visitForeachLoop(JCEnhancedForLoop tree) {
  1158         Env<AttrContext> loopEnv =
  1159             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
  1160         try {
  1161             attribStat(tree.var, loopEnv);
  1162             Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
  1163             chk.checkNonVoid(tree.pos(), exprType);
  1164             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
  1165             if (elemtype == null) {
  1166                 // or perhaps expr implements Iterable<T>?
  1167                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
  1168                 if (base == null) {
  1169                     log.error(tree.expr.pos(),
  1170                             "foreach.not.applicable.to.type",
  1171                             exprType,
  1172                             diags.fragment("type.req.array.or.iterable"));
  1173                     elemtype = types.createErrorType(exprType);
  1174                 } else {
  1175                     List<Type> iterableParams = base.allparams();
  1176                     elemtype = iterableParams.isEmpty()
  1177                         ? syms.objectType
  1178                         : types.upperBound(iterableParams.head);
  1181             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
  1182             loopEnv.tree = tree; // before, we were not in loop!
  1183             attribStat(tree.body, loopEnv);
  1184             result = null;
  1186         finally {
  1187             loopEnv.info.scope.leave();
  1191     public void visitLabelled(JCLabeledStatement tree) {
  1192         // Check that label is not used in an enclosing statement
  1193         Env<AttrContext> env1 = env;
  1194         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
  1195             if (env1.tree.hasTag(LABELLED) &&
  1196                 ((JCLabeledStatement) env1.tree).label == tree.label) {
  1197                 log.error(tree.pos(), "label.already.in.use",
  1198                           tree.label);
  1199                 break;
  1201             env1 = env1.next;
  1204         attribStat(tree.body, env.dup(tree));
  1205         result = null;
  1208     public void visitSwitch(JCSwitch tree) {
  1209         Type seltype = attribExpr(tree.selector, env);
  1211         Env<AttrContext> switchEnv =
  1212             env.dup(tree, env.info.dup(env.info.scope.dup()));
  1214         try {
  1216             boolean enumSwitch =
  1217                 allowEnums &&
  1218                 (seltype.tsym.flags() & Flags.ENUM) != 0;
  1219             boolean stringSwitch = false;
  1220             if (types.isSameType(seltype, syms.stringType)) {
  1221                 if (allowStringsInSwitch) {
  1222                     stringSwitch = true;
  1223                 } else {
  1224                     log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName);
  1227             if (!enumSwitch && !stringSwitch)
  1228                 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
  1230             // Attribute all cases and
  1231             // check that there are no duplicate case labels or default clauses.
  1232             Set<Object> labels = new HashSet<Object>(); // The set of case labels.
  1233             boolean hasDefault = false;      // Is there a default label?
  1234             for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
  1235                 JCCase c = l.head;
  1236                 Env<AttrContext> caseEnv =
  1237                     switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
  1238                 try {
  1239                     if (c.pat != null) {
  1240                         if (enumSwitch) {
  1241                             Symbol sym = enumConstant(c.pat, seltype);
  1242                             if (sym == null) {
  1243                                 log.error(c.pat.pos(), "enum.label.must.be.unqualified.enum");
  1244                             } else if (!labels.add(sym)) {
  1245                                 log.error(c.pos(), "duplicate.case.label");
  1247                         } else {
  1248                             Type pattype = attribExpr(c.pat, switchEnv, seltype);
  1249                             if (!pattype.hasTag(ERROR)) {
  1250                                 if (pattype.constValue() == null) {
  1251                                     log.error(c.pat.pos(),
  1252                                               (stringSwitch ? "string.const.req" : "const.expr.req"));
  1253                                 } else if (labels.contains(pattype.constValue())) {
  1254                                     log.error(c.pos(), "duplicate.case.label");
  1255                                 } else {
  1256                                     labels.add(pattype.constValue());
  1260                     } else if (hasDefault) {
  1261                         log.error(c.pos(), "duplicate.default.label");
  1262                     } else {
  1263                         hasDefault = true;
  1265                     attribStats(c.stats, caseEnv);
  1266                 } finally {
  1267                     caseEnv.info.scope.leave();
  1268                     addVars(c.stats, switchEnv.info.scope);
  1272             result = null;
  1274         finally {
  1275             switchEnv.info.scope.leave();
  1278     // where
  1279         /** Add any variables defined in stats to the switch scope. */
  1280         private static void addVars(List<JCStatement> stats, Scope switchScope) {
  1281             for (;stats.nonEmpty(); stats = stats.tail) {
  1282                 JCTree stat = stats.head;
  1283                 if (stat.hasTag(VARDEF))
  1284                     switchScope.enter(((JCVariableDecl) stat).sym);
  1287     // where
  1288     /** Return the selected enumeration constant symbol, or null. */
  1289     private Symbol enumConstant(JCTree tree, Type enumType) {
  1290         if (!tree.hasTag(IDENT)) {
  1291             log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
  1292             return syms.errSymbol;
  1294         JCIdent ident = (JCIdent)tree;
  1295         Name name = ident.name;
  1296         for (Scope.Entry e = enumType.tsym.members().lookup(name);
  1297              e.scope != null; e = e.next()) {
  1298             if (e.sym.kind == VAR) {
  1299                 Symbol s = ident.sym = e.sym;
  1300                 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
  1301                 ident.type = s.type;
  1302                 return ((s.flags_field & Flags.ENUM) == 0)
  1303                     ? null : s;
  1306         return null;
  1309     public void visitSynchronized(JCSynchronized tree) {
  1310         chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
  1311         attribStat(tree.body, env);
  1312         result = null;
  1315     public void visitTry(JCTry tree) {
  1316         // Create a new local environment with a local
  1317         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
  1318         try {
  1319             boolean isTryWithResource = tree.resources.nonEmpty();
  1320             // Create a nested environment for attributing the try block if needed
  1321             Env<AttrContext> tryEnv = isTryWithResource ?
  1322                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
  1323                 localEnv;
  1324             try {
  1325                 // Attribute resource declarations
  1326                 for (JCTree resource : tree.resources) {
  1327                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
  1328                         @Override
  1329                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
  1330                             chk.basicHandler.report(pos, diags.fragment("try.not.applicable.to.type", details));
  1332                     };
  1333                     ResultInfo twrResult = new ResultInfo(VAL, syms.autoCloseableType, twrContext);
  1334                     if (resource.hasTag(VARDEF)) {
  1335                         attribStat(resource, tryEnv);
  1336                         twrResult.check(resource, resource.type);
  1338                         //check that resource type cannot throw InterruptedException
  1339                         checkAutoCloseable(resource.pos(), localEnv, resource.type);
  1341                         VarSymbol var = ((JCVariableDecl) resource).sym;
  1342                         var.setData(ElementKind.RESOURCE_VARIABLE);
  1343                     } else {
  1344                         attribTree(resource, tryEnv, twrResult);
  1347                 // Attribute body
  1348                 attribStat(tree.body, tryEnv);
  1349             } finally {
  1350                 if (isTryWithResource)
  1351                     tryEnv.info.scope.leave();
  1354             // Attribute catch clauses
  1355             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
  1356                 JCCatch c = l.head;
  1357                 Env<AttrContext> catchEnv =
  1358                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
  1359                 try {
  1360                     Type ctype = attribStat(c.param, catchEnv);
  1361                     if (TreeInfo.isMultiCatch(c)) {
  1362                         //multi-catch parameter is implicitly marked as final
  1363                         c.param.sym.flags_field |= FINAL | UNION;
  1365                     if (c.param.sym.kind == Kinds.VAR) {
  1366                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
  1368                     chk.checkType(c.param.vartype.pos(),
  1369                                   chk.checkClassType(c.param.vartype.pos(), ctype),
  1370                                   syms.throwableType);
  1371                     attribStat(c.body, catchEnv);
  1372                 } finally {
  1373                     catchEnv.info.scope.leave();
  1377             // Attribute finalizer
  1378             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
  1379             result = null;
  1381         finally {
  1382             localEnv.info.scope.leave();
  1386     void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
  1387         if (!resource.isErroneous() &&
  1388             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
  1389             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
  1390             Symbol close = syms.noSymbol;
  1391             Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log);
  1392             try {
  1393                 close = rs.resolveQualifiedMethod(pos,
  1394                         env,
  1395                         resource,
  1396                         names.close,
  1397                         List.<Type>nil(),
  1398                         List.<Type>nil());
  1400             finally {
  1401                 log.popDiagnosticHandler(discardHandler);
  1403             if (close.kind == MTH &&
  1404                     close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
  1405                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
  1406                     env.info.lint.isEnabled(LintCategory.TRY)) {
  1407                 log.warning(LintCategory.TRY, pos, "try.resource.throws.interrupted.exc", resource);
  1412     public void visitConditional(JCConditional tree) {
  1413         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
  1415         tree.polyKind = (!allowPoly ||
  1416                 pt().hasTag(NONE) && pt() != Type.recoveryType ||
  1417                 isBooleanOrNumeric(env, tree)) ?
  1418                 PolyKind.STANDALONE : PolyKind.POLY;
  1420         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
  1421             //cannot get here (i.e. it means we are returning from void method - which is already an error)
  1422             resultInfo.checkContext.report(tree, diags.fragment("conditional.target.cant.be.void"));
  1423             result = tree.type = types.createErrorType(resultInfo.pt);
  1424             return;
  1427         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
  1428                 unknownExprInfo :
  1429                 resultInfo.dup(new Check.NestedCheckContext(resultInfo.checkContext) {
  1430                     //this will use enclosing check context to check compatibility of
  1431                     //subexpression against target type; if we are in a method check context,
  1432                     //depending on whether boxing is allowed, we could have incompatibilities
  1433                     @Override
  1434                     public void report(DiagnosticPosition pos, JCDiagnostic details) {
  1435                         enclosingContext.report(pos, diags.fragment("incompatible.type.in.conditional", details));
  1437                 });
  1439         Type truetype = attribTree(tree.truepart, env, condInfo);
  1440         Type falsetype = attribTree(tree.falsepart, env, condInfo);
  1442         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(tree, truetype, falsetype) : pt();
  1443         if (condtype.constValue() != null &&
  1444                 truetype.constValue() != null &&
  1445                 falsetype.constValue() != null &&
  1446                 !owntype.hasTag(NONE)) {
  1447             //constant folding
  1448             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
  1450         result = check(tree, owntype, VAL, resultInfo);
  1452     //where
  1453         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
  1454             switch (tree.getTag()) {
  1455                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
  1456                               ((JCLiteral)tree).typetag == BOOLEAN ||
  1457                               ((JCLiteral)tree).typetag == BOT;
  1458                 case LAMBDA: case REFERENCE: return false;
  1459                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
  1460                 case CONDEXPR:
  1461                     JCConditional condTree = (JCConditional)tree;
  1462                     return isBooleanOrNumeric(env, condTree.truepart) &&
  1463                             isBooleanOrNumeric(env, condTree.falsepart);
  1464                 case APPLY:
  1465                     JCMethodInvocation speculativeMethodTree =
  1466                             (JCMethodInvocation)deferredAttr.attribSpeculative(tree, env, unknownExprInfo);
  1467                     Type owntype = TreeInfo.symbol(speculativeMethodTree.meth).type.getReturnType();
  1468                     return types.unboxedTypeOrType(owntype).isPrimitive();
  1469                 case NEWCLASS:
  1470                     JCExpression className =
  1471                             removeClassParams.translate(((JCNewClass)tree).clazz);
  1472                     JCExpression speculativeNewClassTree =
  1473                             (JCExpression)deferredAttr.attribSpeculative(className, env, unknownTypeInfo);
  1474                     return types.unboxedTypeOrType(speculativeNewClassTree.type).isPrimitive();
  1475                 default:
  1476                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo).type;
  1477                     speculativeType = types.unboxedTypeOrType(speculativeType);
  1478                     return speculativeType.isPrimitive();
  1481         //where
  1482             TreeTranslator removeClassParams = new TreeTranslator() {
  1483                 @Override
  1484                 public void visitTypeApply(JCTypeApply tree) {
  1485                     result = translate(tree.clazz);
  1487             };
  1489         /** Compute the type of a conditional expression, after
  1490          *  checking that it exists.  See JLS 15.25. Does not take into
  1491          *  account the special case where condition and both arms
  1492          *  are constants.
  1494          *  @param pos      The source position to be used for error
  1495          *                  diagnostics.
  1496          *  @param thentype The type of the expression's then-part.
  1497          *  @param elsetype The type of the expression's else-part.
  1498          */
  1499         private Type condType(DiagnosticPosition pos,
  1500                                Type thentype, Type elsetype) {
  1501             // If same type, that is the result
  1502             if (types.isSameType(thentype, elsetype))
  1503                 return thentype.baseType();
  1505             Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
  1506                 ? thentype : types.unboxedType(thentype);
  1507             Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
  1508                 ? elsetype : types.unboxedType(elsetype);
  1510             // Otherwise, if both arms can be converted to a numeric
  1511             // type, return the least numeric type that fits both arms
  1512             // (i.e. return larger of the two, or return int if one
  1513             // arm is short, the other is char).
  1514             if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
  1515                 // If one arm has an integer subrange type (i.e., byte,
  1516                 // short, or char), and the other is an integer constant
  1517                 // that fits into the subrange, return the subrange type.
  1518                 if (thenUnboxed.getTag().isStrictSubRangeOf(INT) && elseUnboxed.hasTag(INT) &&
  1519                     types.isAssignable(elseUnboxed, thenUnboxed))
  1520                     return thenUnboxed.baseType();
  1521                 if (elseUnboxed.getTag().isStrictSubRangeOf(INT) && thenUnboxed.hasTag(INT) &&
  1522                     types.isAssignable(thenUnboxed, elseUnboxed))
  1523                     return elseUnboxed.baseType();
  1525                 for (TypeTag tag : TypeTag.values()) {
  1526                     if (tag.ordinal() >= TypeTag.getTypeTagCount()) break;
  1527                     Type candidate = syms.typeOfTag[tag.ordinal()];
  1528                     if (candidate != null &&
  1529                         candidate.isPrimitive() &&
  1530                         types.isSubtype(thenUnboxed, candidate) &&
  1531                         types.isSubtype(elseUnboxed, candidate))
  1532                         return candidate;
  1536             // Those were all the cases that could result in a primitive
  1537             if (allowBoxing) {
  1538                 if (thentype.isPrimitive())
  1539                     thentype = types.boxedClass(thentype).type;
  1540                 if (elsetype.isPrimitive())
  1541                     elsetype = types.boxedClass(elsetype).type;
  1544             if (types.isSubtype(thentype, elsetype))
  1545                 return elsetype.baseType();
  1546             if (types.isSubtype(elsetype, thentype))
  1547                 return thentype.baseType();
  1549             if (!allowBoxing || thentype.hasTag(VOID) || elsetype.hasTag(VOID)) {
  1550                 log.error(pos, "neither.conditional.subtype",
  1551                           thentype, elsetype);
  1552                 return thentype.baseType();
  1555             // both are known to be reference types.  The result is
  1556             // lub(thentype,elsetype). This cannot fail, as it will
  1557             // always be possible to infer "Object" if nothing better.
  1558             return types.lub(thentype.baseType(), elsetype.baseType());
  1561     public void visitIf(JCIf tree) {
  1562         attribExpr(tree.cond, env, syms.booleanType);
  1563         attribStat(tree.thenpart, env);
  1564         if (tree.elsepart != null)
  1565             attribStat(tree.elsepart, env);
  1566         chk.checkEmptyIf(tree);
  1567         result = null;
  1570     public void visitExec(JCExpressionStatement tree) {
  1571         //a fresh environment is required for 292 inference to work properly ---
  1572         //see Infer.instantiatePolymorphicSignatureInstance()
  1573         Env<AttrContext> localEnv = env.dup(tree);
  1574         attribExpr(tree.expr, localEnv);
  1575         result = null;
  1578     public void visitBreak(JCBreak tree) {
  1579         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
  1580         result = null;
  1583     public void visitContinue(JCContinue tree) {
  1584         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
  1585         result = null;
  1587     //where
  1588         /** Return the target of a break or continue statement, if it exists,
  1589          *  report an error if not.
  1590          *  Note: The target of a labelled break or continue is the
  1591          *  (non-labelled) statement tree referred to by the label,
  1592          *  not the tree representing the labelled statement itself.
  1594          *  @param pos     The position to be used for error diagnostics
  1595          *  @param tag     The tag of the jump statement. This is either
  1596          *                 Tree.BREAK or Tree.CONTINUE.
  1597          *  @param label   The label of the jump statement, or null if no
  1598          *                 label is given.
  1599          *  @param env     The environment current at the jump statement.
  1600          */
  1601         private JCTree findJumpTarget(DiagnosticPosition pos,
  1602                                     JCTree.Tag tag,
  1603                                     Name label,
  1604                                     Env<AttrContext> env) {
  1605             // Search environments outwards from the point of jump.
  1606             Env<AttrContext> env1 = env;
  1607             LOOP:
  1608             while (env1 != null) {
  1609                 switch (env1.tree.getTag()) {
  1610                     case LABELLED:
  1611                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
  1612                         if (label == labelled.label) {
  1613                             // If jump is a continue, check that target is a loop.
  1614                             if (tag == CONTINUE) {
  1615                                 if (!labelled.body.hasTag(DOLOOP) &&
  1616                                         !labelled.body.hasTag(WHILELOOP) &&
  1617                                         !labelled.body.hasTag(FORLOOP) &&
  1618                                         !labelled.body.hasTag(FOREACHLOOP))
  1619                                     log.error(pos, "not.loop.label", label);
  1620                                 // Found labelled statement target, now go inwards
  1621                                 // to next non-labelled tree.
  1622                                 return TreeInfo.referencedStatement(labelled);
  1623                             } else {
  1624                                 return labelled;
  1627                         break;
  1628                     case DOLOOP:
  1629                     case WHILELOOP:
  1630                     case FORLOOP:
  1631                     case FOREACHLOOP:
  1632                         if (label == null) return env1.tree;
  1633                         break;
  1634                     case SWITCH:
  1635                         if (label == null && tag == BREAK) return env1.tree;
  1636                         break;
  1637                     case LAMBDA:
  1638                     case METHODDEF:
  1639                     case CLASSDEF:
  1640                         break LOOP;
  1641                     default:
  1643                 env1 = env1.next;
  1645             if (label != null)
  1646                 log.error(pos, "undef.label", label);
  1647             else if (tag == CONTINUE)
  1648                 log.error(pos, "cont.outside.loop");
  1649             else
  1650                 log.error(pos, "break.outside.switch.loop");
  1651             return null;
  1654     public void visitReturn(JCReturn tree) {
  1655         // Check that there is an enclosing method which is
  1656         // nested within than the enclosing class.
  1657         if (env.info.returnResult == null) {
  1658             log.error(tree.pos(), "ret.outside.meth");
  1659         } else {
  1660             // Attribute return expression, if it exists, and check that
  1661             // it conforms to result type of enclosing method.
  1662             if (tree.expr != null) {
  1663                 if (env.info.returnResult.pt.hasTag(VOID)) {
  1664                     env.info.returnResult.checkContext.report(tree.expr.pos(),
  1665                               diags.fragment("unexpected.ret.val"));
  1667                 attribTree(tree.expr, env, env.info.returnResult);
  1668             } else if (!env.info.returnResult.pt.hasTag(VOID)) {
  1669                 env.info.returnResult.checkContext.report(tree.pos(),
  1670                               diags.fragment("missing.ret.val"));
  1673         result = null;
  1676     public void visitThrow(JCThrow tree) {
  1677         Type owntype = attribExpr(tree.expr, env, allowPoly ? Type.noType : syms.throwableType);
  1678         if (allowPoly) {
  1679             chk.checkType(tree, owntype, syms.throwableType);
  1681         result = null;
  1684     public void visitAssert(JCAssert tree) {
  1685         attribExpr(tree.cond, env, syms.booleanType);
  1686         if (tree.detail != null) {
  1687             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
  1689         result = null;
  1692      /** Visitor method for method invocations.
  1693      *  NOTE: The method part of an application will have in its type field
  1694      *        the return type of the method, not the method's type itself!
  1695      */
  1696     public void visitApply(JCMethodInvocation tree) {
  1697         // The local environment of a method application is
  1698         // a new environment nested in the current one.
  1699         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
  1701         // The types of the actual method arguments.
  1702         List<Type> argtypes;
  1704         // The types of the actual method type arguments.
  1705         List<Type> typeargtypes = null;
  1707         Name methName = TreeInfo.name(tree.meth);
  1709         boolean isConstructorCall =
  1710             methName == names._this || methName == names._super;
  1712         if (isConstructorCall) {
  1713             // We are seeing a ...this(...) or ...super(...) call.
  1714             // Check that this is the first statement in a constructor.
  1715             if (checkFirstConstructorStat(tree, env)) {
  1717                 // Record the fact
  1718                 // that this is a constructor call (using isSelfCall).
  1719                 localEnv.info.isSelfCall = true;
  1721                 // Attribute arguments, yielding list of argument types.
  1722                 argtypes = attribArgs(tree.args, localEnv);
  1723                 typeargtypes = attribTypes(tree.typeargs, localEnv);
  1725                 // Variable `site' points to the class in which the called
  1726                 // constructor is defined.
  1727                 Type site = env.enclClass.sym.type;
  1728                 if (methName == names._super) {
  1729                     if (site == syms.objectType) {
  1730                         log.error(tree.meth.pos(), "no.superclass", site);
  1731                         site = types.createErrorType(syms.objectType);
  1732                     } else {
  1733                         site = types.supertype(site);
  1737                 if (site.hasTag(CLASS)) {
  1738                     Type encl = site.getEnclosingType();
  1739                     while (encl != null && encl.hasTag(TYPEVAR))
  1740                         encl = encl.getUpperBound();
  1741                     if (encl.hasTag(CLASS)) {
  1742                         // we are calling a nested class
  1744                         if (tree.meth.hasTag(SELECT)) {
  1745                             JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
  1747                             // We are seeing a prefixed call, of the form
  1748                             //     <expr>.super(...).
  1749                             // Check that the prefix expression conforms
  1750                             // to the outer instance type of the class.
  1751                             chk.checkRefType(qualifier.pos(),
  1752                                              attribExpr(qualifier, localEnv,
  1753                                                         encl));
  1754                         } else if (methName == names._super) {
  1755                             // qualifier omitted; check for existence
  1756                             // of an appropriate implicit qualifier.
  1757                             rs.resolveImplicitThis(tree.meth.pos(),
  1758                                                    localEnv, site, true);
  1760                     } else if (tree.meth.hasTag(SELECT)) {
  1761                         log.error(tree.meth.pos(), "illegal.qual.not.icls",
  1762                                   site.tsym);
  1765                     // if we're calling a java.lang.Enum constructor,
  1766                     // prefix the implicit String and int parameters
  1767                     if (site.tsym == syms.enumSym && allowEnums)
  1768                         argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
  1770                     // Resolve the called constructor under the assumption
  1771                     // that we are referring to a superclass instance of the
  1772                     // current instance (JLS ???).
  1773                     boolean selectSuperPrev = localEnv.info.selectSuper;
  1774                     localEnv.info.selectSuper = true;
  1775                     localEnv.info.pendingResolutionPhase = null;
  1776                     Symbol sym = rs.resolveConstructor(
  1777                         tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
  1778                     localEnv.info.selectSuper = selectSuperPrev;
  1780                     // Set method symbol to resolved constructor...
  1781                     TreeInfo.setSymbol(tree.meth, sym);
  1783                     // ...and check that it is legal in the current context.
  1784                     // (this will also set the tree's type)
  1785                     Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
  1786                     checkId(tree.meth, site, sym, localEnv, new ResultInfo(MTH, mpt));
  1788                 // Otherwise, `site' is an error type and we do nothing
  1790             result = tree.type = syms.voidType;
  1791         } else {
  1792             // Otherwise, we are seeing a regular method call.
  1793             // Attribute the arguments, yielding list of argument types, ...
  1794             argtypes = attribArgs(tree.args, localEnv);
  1795             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
  1797             // ... and attribute the method using as a prototype a methodtype
  1798             // whose formal argument types is exactly the list of actual
  1799             // arguments (this will also set the method symbol).
  1800             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
  1801             localEnv.info.pendingResolutionPhase = null;
  1802             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(VAL, mpt, resultInfo.checkContext));
  1804             // Compute the result type.
  1805             Type restype = mtype.getReturnType();
  1806             if (restype.hasTag(WILDCARD))
  1807                 throw new AssertionError(mtype);
  1809             Type qualifier = (tree.meth.hasTag(SELECT))
  1810                     ? ((JCFieldAccess) tree.meth).selected.type
  1811                     : env.enclClass.sym.type;
  1812             restype = adjustMethodReturnType(qualifier, methName, argtypes, restype);
  1814             chk.checkRefTypes(tree.typeargs, typeargtypes);
  1816             // Check that value of resulting type is admissible in the
  1817             // current context.  Also, capture the return type
  1818             result = check(tree, capture(restype), VAL, resultInfo);
  1820             if (localEnv.info.lastResolveVarargs())
  1821                 Assert.check(result.isErroneous() || tree.varargsElement != null);
  1823         chk.validate(tree.typeargs, localEnv);
  1825     //where
  1826         Type adjustMethodReturnType(Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
  1827             if (allowCovariantReturns &&
  1828                     methodName == names.clone &&
  1829                 types.isArray(qualifierType)) {
  1830                 // as a special case, array.clone() has a result that is
  1831                 // the same as static type of the array being cloned
  1832                 return qualifierType;
  1833             } else if (allowGenerics &&
  1834                     methodName == names.getClass &&
  1835                     argtypes.isEmpty()) {
  1836                 // as a special case, x.getClass() has type Class<? extends |X|>
  1837                 return new ClassType(restype.getEnclosingType(),
  1838                               List.<Type>of(new WildcardType(types.erasure(qualifierType),
  1839                                                                BoundKind.EXTENDS,
  1840                                                                syms.boundClass)),
  1841                               restype.tsym);
  1842             } else {
  1843                 return restype;
  1847         /** Check that given application node appears as first statement
  1848          *  in a constructor call.
  1849          *  @param tree   The application node
  1850          *  @param env    The environment current at the application.
  1851          */
  1852         boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
  1853             JCMethodDecl enclMethod = env.enclMethod;
  1854             if (enclMethod != null && enclMethod.name == names.init) {
  1855                 JCBlock body = enclMethod.body;
  1856                 if (body.stats.head.hasTag(EXEC) &&
  1857                     ((JCExpressionStatement) body.stats.head).expr == tree)
  1858                     return true;
  1860             log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
  1861                       TreeInfo.name(tree.meth));
  1862             return false;
  1865         /** Obtain a method type with given argument types.
  1866          */
  1867         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
  1868             MethodType mt = new MethodType(argtypes, restype, List.<Type>nil(), syms.methodClass);
  1869             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
  1872     public void visitNewClass(final JCNewClass tree) {
  1873         Type owntype = types.createErrorType(tree.type);
  1875         // The local environment of a class creation is
  1876         // a new environment nested in the current one.
  1877         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
  1879         // The anonymous inner class definition of the new expression,
  1880         // if one is defined by it.
  1881         JCClassDecl cdef = tree.def;
  1883         // If enclosing class is given, attribute it, and
  1884         // complete class name to be fully qualified
  1885         JCExpression clazz = tree.clazz; // Class field following new
  1886         JCExpression clazzid;            // Identifier in class field
  1887         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
  1888         annoclazzid = null;
  1890         if (clazz.hasTag(TYPEAPPLY)) {
  1891             clazzid = ((JCTypeApply) clazz).clazz;
  1892             if (clazzid.hasTag(ANNOTATED_TYPE)) {
  1893                 annoclazzid = (JCAnnotatedType) clazzid;
  1894                 clazzid = annoclazzid.underlyingType;
  1896         } else {
  1897             if (clazz.hasTag(ANNOTATED_TYPE)) {
  1898                 annoclazzid = (JCAnnotatedType) clazz;
  1899                 clazzid = annoclazzid.underlyingType;
  1900             } else {
  1901                 clazzid = clazz;
  1905         JCExpression clazzid1 = clazzid; // The same in fully qualified form
  1907         if (tree.encl != null) {
  1908             // We are seeing a qualified new, of the form
  1909             //    <expr>.new C <...> (...) ...
  1910             // In this case, we let clazz stand for the name of the
  1911             // allocated class C prefixed with the type of the qualifier
  1912             // expression, so that we can
  1913             // resolve it with standard techniques later. I.e., if
  1914             // <expr> has type T, then <expr>.new C <...> (...)
  1915             // yields a clazz T.C.
  1916             Type encltype = chk.checkRefType(tree.encl.pos(),
  1917                                              attribExpr(tree.encl, env));
  1918             // TODO 308: in <expr>.new C, do we also want to add the type annotations
  1919             // from expr to the combined type, or not? Yes, do this.
  1920             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
  1921                                                  ((JCIdent) clazzid).name);
  1923             if (clazz.hasTag(ANNOTATED_TYPE)) {
  1924                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
  1925                 List<JCAnnotation> annos = annoType.annotations;
  1927                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
  1928                     clazzid1 = make.at(tree.pos).
  1929                         TypeApply(clazzid1,
  1930                                   ((JCTypeApply) clazz).arguments);
  1933                 clazzid1 = make.at(tree.pos).
  1934                     AnnotatedType(annos, clazzid1);
  1935             } else if (clazz.hasTag(TYPEAPPLY)) {
  1936                 clazzid1 = make.at(tree.pos).
  1937                     TypeApply(clazzid1,
  1938                               ((JCTypeApply) clazz).arguments);
  1941             clazz = clazzid1;
  1944         // Attribute clazz expression and store
  1945         // symbol + type back into the attributed tree.
  1946         Type clazztype = TreeInfo.isEnumInit(env.tree) ?
  1947             attribIdentAsEnumType(env, (JCIdent)clazz) :
  1948             attribType(clazz, env);
  1950         clazztype = chk.checkDiamond(tree, clazztype);
  1951         chk.validate(clazz, localEnv);
  1952         if (tree.encl != null) {
  1953             // We have to work in this case to store
  1954             // symbol + type back into the attributed tree.
  1955             tree.clazz.type = clazztype;
  1956             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
  1957             clazzid.type = ((JCIdent) clazzid).sym.type;
  1958             if (annoclazzid != null) {
  1959                 annoclazzid.type = clazzid.type;
  1961             if (!clazztype.isErroneous()) {
  1962                 if (cdef != null && clazztype.tsym.isInterface()) {
  1963                     log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
  1964                 } else if (clazztype.tsym.isStatic()) {
  1965                     log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
  1968         } else if (!clazztype.tsym.isInterface() &&
  1969                    clazztype.getEnclosingType().hasTag(CLASS)) {
  1970             // Check for the existence of an apropos outer instance
  1971             rs.resolveImplicitThis(tree.pos(), env, clazztype);
  1974         // Attribute constructor arguments.
  1975         List<Type> argtypes = attribArgs(tree.args, localEnv);
  1976         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
  1978         // If we have made no mistakes in the class type...
  1979         if (clazztype.hasTag(CLASS)) {
  1980             // Enums may not be instantiated except implicitly
  1981             if (allowEnums &&
  1982                 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
  1983                 (!env.tree.hasTag(VARDEF) ||
  1984                  (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
  1985                  ((JCVariableDecl) env.tree).init != tree))
  1986                 log.error(tree.pos(), "enum.cant.be.instantiated");
  1987             // Check that class is not abstract
  1988             if (cdef == null &&
  1989                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
  1990                 log.error(tree.pos(), "abstract.cant.be.instantiated",
  1991                           clazztype.tsym);
  1992             } else if (cdef != null && clazztype.tsym.isInterface()) {
  1993                 // Check that no constructor arguments are given to
  1994                 // anonymous classes implementing an interface
  1995                 if (!argtypes.isEmpty())
  1996                     log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
  1998                 if (!typeargtypes.isEmpty())
  1999                     log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
  2001                 // Error recovery: pretend no arguments were supplied.
  2002                 argtypes = List.nil();
  2003                 typeargtypes = List.nil();
  2004             } else if (TreeInfo.isDiamond(tree)) {
  2005                 ClassType site = new ClassType(clazztype.getEnclosingType(),
  2006                             clazztype.tsym.type.getTypeArguments(),
  2007                             clazztype.tsym);
  2009                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
  2010                 diamondEnv.info.selectSuper = cdef != null;
  2011                 diamondEnv.info.pendingResolutionPhase = null;
  2013                 //if the type of the instance creation expression is a class type
  2014                 //apply method resolution inference (JLS 15.12.2.7). The return type
  2015                 //of the resolved constructor will be a partially instantiated type
  2016                 Symbol constructor = rs.resolveDiamond(tree.pos(),
  2017                             diamondEnv,
  2018                             site,
  2019                             argtypes,
  2020                             typeargtypes);
  2021                 tree.constructor = constructor.baseSymbol();
  2023                 final TypeSymbol csym = clazztype.tsym;
  2024                 ResultInfo diamondResult = new ResultInfo(MTH, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes), new Check.NestedCheckContext(resultInfo.checkContext) {
  2025                     @Override
  2026                     public void report(DiagnosticPosition _unused, JCDiagnostic details) {
  2027                         enclosingContext.report(tree.clazz,
  2028                                 diags.fragment("cant.apply.diamond.1", diags.fragment("diamond", csym), details));
  2030                 });
  2031                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
  2032                 constructorType = checkId(tree, site,
  2033                         constructor,
  2034                         diamondEnv,
  2035                         diamondResult);
  2037                 tree.clazz.type = types.createErrorType(clazztype);
  2038                 if (!constructorType.isErroneous()) {
  2039                     tree.clazz.type = clazztype = constructorType.getReturnType();
  2040                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
  2042                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
  2045             // Resolve the called constructor under the assumption
  2046             // that we are referring to a superclass instance of the
  2047             // current instance (JLS ???).
  2048             else {
  2049                 //the following code alters some of the fields in the current
  2050                 //AttrContext - hence, the current context must be dup'ed in
  2051                 //order to avoid downstream failures
  2052                 Env<AttrContext> rsEnv = localEnv.dup(tree);
  2053                 rsEnv.info.selectSuper = cdef != null;
  2054                 rsEnv.info.pendingResolutionPhase = null;
  2055                 tree.constructor = rs.resolveConstructor(
  2056                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
  2057                 if (cdef == null) { //do not check twice!
  2058                     tree.constructorType = checkId(tree,
  2059                             clazztype,
  2060                             tree.constructor,
  2061                             rsEnv,
  2062                             new ResultInfo(MTH, newMethodTemplate(syms.voidType, argtypes, typeargtypes)));
  2063                     if (rsEnv.info.lastResolveVarargs())
  2064                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
  2066                 findDiamondIfNeeded(localEnv, tree, clazztype);
  2069             if (cdef != null) {
  2070                 // We are seeing an anonymous class instance creation.
  2071                 // In this case, the class instance creation
  2072                 // expression
  2073                 //
  2074                 //    E.new <typeargs1>C<typargs2>(args) { ... }
  2075                 //
  2076                 // is represented internally as
  2077                 //
  2078                 //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
  2079                 //
  2080                 // This expression is then *transformed* as follows:
  2081                 //
  2082                 // (1) add a STATIC flag to the class definition
  2083                 //     if the current environment is static
  2084                 // (2) add an extends or implements clause
  2085                 // (3) add a constructor.
  2086                 //
  2087                 // For instance, if C is a class, and ET is the type of E,
  2088                 // the expression
  2089                 //
  2090                 //    E.new <typeargs1>C<typargs2>(args) { ... }
  2091                 //
  2092                 // is translated to (where X is a fresh name and typarams is the
  2093                 // parameter list of the super constructor):
  2094                 //
  2095                 //   new <typeargs1>X(<*nullchk*>E, args) where
  2096                 //     X extends C<typargs2> {
  2097                 //       <typarams> X(ET e, args) {
  2098                 //         e.<typeargs1>super(args)
  2099                 //       }
  2100                 //       ...
  2101                 //     }
  2102                 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
  2104                 if (clazztype.tsym.isInterface()) {
  2105                     cdef.implementing = List.of(clazz);
  2106                 } else {
  2107                     cdef.extending = clazz;
  2110                 attribStat(cdef, localEnv);
  2112                 checkLambdaCandidate(tree, cdef.sym, clazztype);
  2114                 // If an outer instance is given,
  2115                 // prefix it to the constructor arguments
  2116                 // and delete it from the new expression
  2117                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
  2118                     tree.args = tree.args.prepend(makeNullCheck(tree.encl));
  2119                     argtypes = argtypes.prepend(tree.encl.type);
  2120                     tree.encl = null;
  2123                 // Reassign clazztype and recompute constructor.
  2124                 clazztype = cdef.sym.type;
  2125                 Symbol sym = tree.constructor = rs.resolveConstructor(
  2126                     tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
  2127                 Assert.check(sym.kind < AMBIGUOUS);
  2128                 tree.constructor = sym;
  2129                 tree.constructorType = checkId(tree,
  2130                     clazztype,
  2131                     tree.constructor,
  2132                     localEnv,
  2133                     new ResultInfo(VAL, newMethodTemplate(syms.voidType, argtypes, typeargtypes)));
  2136             if (tree.constructor != null && tree.constructor.kind == MTH)
  2137                 owntype = clazztype;
  2139         result = check(tree, owntype, VAL, resultInfo);
  2140         chk.validate(tree.typeargs, localEnv);
  2142     //where
  2143         void findDiamondIfNeeded(Env<AttrContext> env, JCNewClass tree, Type clazztype) {
  2144             if (tree.def == null &&
  2145                     !clazztype.isErroneous() &&
  2146                     clazztype.getTypeArguments().nonEmpty() &&
  2147                     findDiamonds) {
  2148                 JCTypeApply ta = (JCTypeApply)tree.clazz;
  2149                 List<JCExpression> prevTypeargs = ta.arguments;
  2150                 try {
  2151                     //create a 'fake' diamond AST node by removing type-argument trees
  2152                     ta.arguments = List.nil();
  2153                     ResultInfo findDiamondResult = new ResultInfo(VAL,
  2154                             resultInfo.checkContext.inferenceContext().free(resultInfo.pt) ? Type.noType : pt());
  2155                     Type inferred = deferredAttr.attribSpeculative(tree, env, findDiamondResult).type;
  2156                     Type polyPt = allowPoly ?
  2157                             syms.objectType :
  2158                             clazztype;
  2159                     if (!inferred.isErroneous() &&
  2160                         types.isAssignable(inferred, pt().hasTag(NONE) ? polyPt : pt(), types.noWarnings)) {
  2161                         String key = types.isSameType(clazztype, inferred) ?
  2162                             "diamond.redundant.args" :
  2163                             "diamond.redundant.args.1";
  2164                         log.warning(tree.clazz.pos(), key, clazztype, inferred);
  2166                 } finally {
  2167                     ta.arguments = prevTypeargs;
  2172             private void checkLambdaCandidate(JCNewClass tree, ClassSymbol csym, Type clazztype) {
  2173                 if (allowLambda &&
  2174                         identifyLambdaCandidate &&
  2175                         clazztype.hasTag(CLASS) &&
  2176                         !pt().hasTag(NONE) &&
  2177                         types.isFunctionalInterface(clazztype.tsym)) {
  2178                     Symbol descriptor = types.findDescriptorSymbol(clazztype.tsym);
  2179                     int count = 0;
  2180                     boolean found = false;
  2181                     for (Symbol sym : csym.members().getElements()) {
  2182                         if ((sym.flags() & SYNTHETIC) != 0 ||
  2183                                 sym.isConstructor()) continue;
  2184                         count++;
  2185                         if (sym.kind != MTH ||
  2186                                 !sym.name.equals(descriptor.name)) continue;
  2187                         Type mtype = types.memberType(clazztype, sym);
  2188                         if (types.overrideEquivalent(mtype, types.memberType(clazztype, descriptor))) {
  2189                             found = true;
  2192                     if (found && count == 1) {
  2193                         log.note(tree.def, "potential.lambda.found");
  2198     /** Make an attributed null check tree.
  2199      */
  2200     public JCExpression makeNullCheck(JCExpression arg) {
  2201         // optimization: X.this is never null; skip null check
  2202         Name name = TreeInfo.name(arg);
  2203         if (name == names._this || name == names._super) return arg;
  2205         JCTree.Tag optag = NULLCHK;
  2206         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
  2207         tree.operator = syms.nullcheck;
  2208         tree.type = arg.type;
  2209         return tree;
  2212     public void visitNewArray(JCNewArray tree) {
  2213         Type owntype = types.createErrorType(tree.type);
  2214         Env<AttrContext> localEnv = env.dup(tree);
  2215         Type elemtype;
  2216         if (tree.elemtype != null) {
  2217             elemtype = attribType(tree.elemtype, localEnv);
  2218             chk.validate(tree.elemtype, localEnv);
  2219             owntype = elemtype;
  2220             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
  2221                 attribExpr(l.head, localEnv, syms.intType);
  2222                 owntype = new ArrayType(owntype, syms.arrayClass);
  2224         } else {
  2225             // we are seeing an untyped aggregate { ... }
  2226             // this is allowed only if the prototype is an array
  2227             if (pt().hasTag(ARRAY)) {
  2228                 elemtype = types.elemtype(pt());
  2229             } else {
  2230                 if (!pt().hasTag(ERROR)) {
  2231                     log.error(tree.pos(), "illegal.initializer.for.type",
  2232                               pt());
  2234                 elemtype = types.createErrorType(pt());
  2237         if (tree.elems != null) {
  2238             attribExprs(tree.elems, localEnv, elemtype);
  2239             owntype = new ArrayType(elemtype, syms.arrayClass);
  2241         if (!types.isReifiable(elemtype))
  2242             log.error(tree.pos(), "generic.array.creation");
  2243         result = check(tree, owntype, VAL, resultInfo);
  2246     /*
  2247      * A lambda expression can only be attributed when a target-type is available.
  2248      * In addition, if the target-type is that of a functional interface whose
  2249      * descriptor contains inference variables in argument position the lambda expression
  2250      * is 'stuck' (see DeferredAttr).
  2251      */
  2252     @Override
  2253     public void visitLambda(final JCLambda that) {
  2254         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
  2255             if (pt().hasTag(NONE)) {
  2256                 //lambda only allowed in assignment or method invocation/cast context
  2257                 log.error(that.pos(), "unexpected.lambda");
  2259             result = that.type = types.createErrorType(pt());
  2260             return;
  2262         //create an environment for attribution of the lambda expression
  2263         final Env<AttrContext> localEnv = lambdaEnv(that, env);
  2264         boolean needsRecovery =
  2265                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
  2266         try {
  2267             Type target = pt();
  2268             List<Type> explicitParamTypes = null;
  2269             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
  2270                 //attribute lambda parameters
  2271                 attribStats(that.params, localEnv);
  2272                 explicitParamTypes = TreeInfo.types(that.params);
  2273                 target = infer.instantiateFunctionalInterface(that, target, explicitParamTypes, resultInfo.checkContext);
  2276             Type lambdaType;
  2277             if (pt() != Type.recoveryType) {
  2278                 target = targetChecker.visit(target, that);
  2279                 lambdaType = types.findDescriptorType(target);
  2280                 chk.checkFunctionalInterface(that, target);
  2281             } else {
  2282                 target = Type.recoveryType;
  2283                 lambdaType = fallbackDescriptorType(that);
  2286             setFunctionalInfo(that, pt(), lambdaType, target, resultInfo.checkContext.inferenceContext());
  2288             if (lambdaType.hasTag(FORALL)) {
  2289                 //lambda expression target desc cannot be a generic method
  2290                 resultInfo.checkContext.report(that, diags.fragment("invalid.generic.lambda.target",
  2291                         lambdaType, kindName(target.tsym), target.tsym));
  2292                 result = that.type = types.createErrorType(pt());
  2293                 return;
  2296             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
  2297                 //add param type info in the AST
  2298                 List<Type> actuals = lambdaType.getParameterTypes();
  2299                 List<JCVariableDecl> params = that.params;
  2301                 boolean arityMismatch = false;
  2303                 while (params.nonEmpty()) {
  2304                     if (actuals.isEmpty()) {
  2305                         //not enough actuals to perform lambda parameter inference
  2306                         arityMismatch = true;
  2308                     //reset previously set info
  2309                     Type argType = arityMismatch ?
  2310                             syms.errType :
  2311                             actuals.head;
  2312                     params.head.vartype = make.Type(argType);
  2313                     params.head.sym = null;
  2314                     actuals = actuals.isEmpty() ?
  2315                             actuals :
  2316                             actuals.tail;
  2317                     params = params.tail;
  2320                 //attribute lambda parameters
  2321                 attribStats(that.params, localEnv);
  2323                 if (arityMismatch) {
  2324                     resultInfo.checkContext.report(that, diags.fragment("incompatible.arg.types.in.lambda"));
  2325                         result = that.type = types.createErrorType(target);
  2326                         return;
  2330             //from this point on, no recovery is needed; if we are in assignment context
  2331             //we will be able to attribute the whole lambda body, regardless of errors;
  2332             //if we are in a 'check' method context, and the lambda is not compatible
  2333             //with the target-type, it will be recovered anyway in Attr.checkId
  2334             needsRecovery = false;
  2336             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
  2337                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
  2338                     new FunctionalReturnContext(resultInfo.checkContext);
  2340             ResultInfo bodyResultInfo = lambdaType.getReturnType() == Type.recoveryType ?
  2341                 recoveryInfo :
  2342                 new ResultInfo(VAL, lambdaType.getReturnType(), funcContext);
  2343             localEnv.info.returnResult = bodyResultInfo;
  2345             Log.DeferredDiagnosticHandler lambdaDeferredHandler = new Log.DeferredDiagnosticHandler(log);
  2346             try {
  2347                 if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
  2348                     attribTree(that.getBody(), localEnv, bodyResultInfo);
  2349                 } else {
  2350                     JCBlock body = (JCBlock)that.body;
  2351                     attribStats(body.stats, localEnv);
  2354                 if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.SPECULATIVE) {
  2355                     //check for errors in lambda body
  2356                     for (JCDiagnostic deferredDiag : lambdaDeferredHandler.getDiagnostics()) {
  2357                         if (deferredDiag.getKind() == JCDiagnostic.Kind.ERROR) {
  2358                             resultInfo.checkContext
  2359                                     .report(that, diags.fragment("bad.arg.types.in.lambda", TreeInfo.types(that.params)));
  2360                             //we mark the lambda as erroneous - this is crucial in the recovery step
  2361                             //as parameter-dependent type error won't be reported in that stage,
  2362                             //meaning that a lambda will be deemed erroeneous only if there is
  2363                             //a target-independent error (which will cause method diagnostic
  2364                             //to be skipped).
  2365                             result = that.type = types.createErrorType(target);
  2366                             return;
  2370             } finally {
  2371                 lambdaDeferredHandler.reportDeferredDiagnostics();
  2372                 log.popDiagnosticHandler(lambdaDeferredHandler);
  2375             result = check(that, target, VAL, resultInfo);
  2377             boolean isSpeculativeRound =
  2378                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
  2380             postAttr(that);
  2381             flow.analyzeLambda(env, that, make, isSpeculativeRound);
  2383             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext, isSpeculativeRound);
  2385             if (!isSpeculativeRound) {
  2386                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, target);
  2388             result = check(that, target, VAL, resultInfo);
  2389         } catch (Types.FunctionDescriptorLookupError ex) {
  2390             JCDiagnostic cause = ex.getDiagnostic();
  2391             resultInfo.checkContext.report(that, cause);
  2392             result = that.type = types.createErrorType(pt());
  2393             return;
  2394         } finally {
  2395             localEnv.info.scope.leave();
  2396             if (needsRecovery) {
  2397                 attribTree(that, env, recoveryInfo);
  2401     //where
  2402         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
  2404             @Override
  2405             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
  2406                 return t.isCompound() ?
  2407                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
  2410             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
  2411                 Symbol desc = types.findDescriptorSymbol(makeNotionalInterface(ict));
  2412                 Type target = null;
  2413                 for (Type bound : ict.getExplicitComponents()) {
  2414                     TypeSymbol boundSym = bound.tsym;
  2415                     if (types.isFunctionalInterface(boundSym) &&
  2416                             types.findDescriptorSymbol(boundSym) == desc) {
  2417                         target = bound;
  2418                     } else if (!boundSym.isInterface() || (boundSym.flags() & ANNOTATION) != 0) {
  2419                         //bound must be an interface
  2420                         reportIntersectionError(pos, "not.an.intf.component", boundSym);
  2423                 return target != null ?
  2424                         target :
  2425                         ict.getExplicitComponents().head; //error recovery
  2428             private TypeSymbol makeNotionalInterface(IntersectionClassType ict) {
  2429                 ListBuffer<Type> targs = ListBuffer.lb();
  2430                 ListBuffer<Type> supertypes = ListBuffer.lb();
  2431                 for (Type i : ict.interfaces_field) {
  2432                     if (i.isParameterized()) {
  2433                         targs.appendList(i.tsym.type.allparams());
  2435                     supertypes.append(i.tsym.type);
  2437                 IntersectionClassType notionalIntf =
  2438                         (IntersectionClassType)types.makeCompoundType(supertypes.toList());
  2439                 notionalIntf.allparams_field = targs.toList();
  2440                 notionalIntf.tsym.flags_field |= INTERFACE;
  2441                 return notionalIntf.tsym;
  2444             private void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) {
  2445                 resultInfo.checkContext.report(pos, diags.fragment("bad.intersection.target.for.functional.expr",
  2446                         diags.fragment(key, args)));
  2448         };
  2450         private Type fallbackDescriptorType(JCExpression tree) {
  2451             switch (tree.getTag()) {
  2452                 case LAMBDA:
  2453                     JCLambda lambda = (JCLambda)tree;
  2454                     List<Type> argtypes = List.nil();
  2455                     for (JCVariableDecl param : lambda.params) {
  2456                         argtypes = param.vartype != null ?
  2457                                 argtypes.append(param.vartype.type) :
  2458                                 argtypes.append(syms.errType);
  2460                     return new MethodType(argtypes, Type.recoveryType,
  2461                             List.of(syms.throwableType), syms.methodClass);
  2462                 case REFERENCE:
  2463                     return new MethodType(List.<Type>nil(), Type.recoveryType,
  2464                             List.of(syms.throwableType), syms.methodClass);
  2465                 default:
  2466                     Assert.error("Cannot get here!");
  2468             return null;
  2471         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
  2472                 final InferenceContext inferenceContext, final Type... ts) {
  2473             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
  2476         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
  2477                 final InferenceContext inferenceContext, final List<Type> ts) {
  2478             if (inferenceContext.free(ts)) {
  2479                 inferenceContext.addFreeTypeListener(ts, new FreeTypeListener() {
  2480                     @Override
  2481                     public void typesInferred(InferenceContext inferenceContext) {
  2482                         checkAccessibleTypes(pos, env, inferenceContext, inferenceContext.asInstTypes(ts));
  2484                 });
  2485             } else {
  2486                 for (Type t : ts) {
  2487                     rs.checkAccessibleType(env, t);
  2492         /**
  2493          * Lambda/method reference have a special check context that ensures
  2494          * that i.e. a lambda return type is compatible with the expected
  2495          * type according to both the inherited context and the assignment
  2496          * context.
  2497          */
  2498         class FunctionalReturnContext extends Check.NestedCheckContext {
  2500             FunctionalReturnContext(CheckContext enclosingContext) {
  2501                 super(enclosingContext);
  2504             @Override
  2505             public boolean compatible(Type found, Type req, Warner warn) {
  2506                 //return type must be compatible in both current context and assignment context
  2507                 return chk.basicHandler.compatible(found, inferenceContext().asFree(req), warn);
  2510             @Override
  2511             public void report(DiagnosticPosition pos, JCDiagnostic details) {
  2512                 enclosingContext.report(pos, diags.fragment("incompatible.ret.type.in.lambda", details));
  2516         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
  2518             JCExpression expr;
  2520             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
  2521                 super(enclosingContext);
  2522                 this.expr = expr;
  2525             @Override
  2526             public boolean compatible(Type found, Type req, Warner warn) {
  2527                 //a void return is compatible with an expression statement lambda
  2528                 return TreeInfo.isExpressionStatement(expr) && req.hasTag(VOID) ||
  2529                         super.compatible(found, req, warn);
  2533         /**
  2534         * Lambda compatibility. Check that given return types, thrown types, parameter types
  2535         * are compatible with the expected functional interface descriptor. This means that:
  2536         * (i) parameter types must be identical to those of the target descriptor; (ii) return
  2537         * types must be compatible with the return type of the expected descriptor;
  2538         * (iii) thrown types must be 'included' in the thrown types list of the expected
  2539         * descriptor.
  2540         */
  2541         private void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext, boolean speculativeAttr) {
  2542             Type returnType = checkContext.inferenceContext().asFree(descriptor.getReturnType());
  2544             //return values have already been checked - but if lambda has no return
  2545             //values, we must ensure that void/value compatibility is correct;
  2546             //this amounts at checking that, if a lambda body can complete normally,
  2547             //the descriptor's return type must be void
  2548             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
  2549                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
  2550                 checkContext.report(tree, diags.fragment("incompatible.ret.type.in.lambda",
  2551                         diags.fragment("missing.ret.val", returnType)));
  2554             List<Type> argTypes = checkContext.inferenceContext().asFree(descriptor.getParameterTypes());
  2555             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
  2556                 checkContext.report(tree, diags.fragment("incompatible.arg.types.in.lambda"));
  2559             if (!speculativeAttr) {
  2560                 List<Type> thrownTypes = checkContext.inferenceContext().asFree(descriptor.getThrownTypes());
  2561                 if (chk.unhandled(tree.inferredThrownTypes == null ? List.<Type>nil() : tree.inferredThrownTypes, thrownTypes).nonEmpty()) {
  2562                     log.error(tree, "incompatible.thrown.types.in.lambda", tree.inferredThrownTypes);
  2567         private Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
  2568             Env<AttrContext> lambdaEnv;
  2569             Symbol owner = env.info.scope.owner;
  2570             if (owner.kind == VAR && owner.owner.kind == TYP) {
  2571                 //field initializer
  2572                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared()));
  2573                 lambdaEnv.info.scope.owner =
  2574                     new MethodSymbol(0, names.empty, null,
  2575                                      env.info.scope.owner);
  2576             } else {
  2577                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
  2579             return lambdaEnv;
  2582     @Override
  2583     public void visitReference(final JCMemberReference that) {
  2584         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
  2585             if (pt().hasTag(NONE)) {
  2586                 //method reference only allowed in assignment or method invocation/cast context
  2587                 log.error(that.pos(), "unexpected.mref");
  2589             result = that.type = types.createErrorType(pt());
  2590             return;
  2592         final Env<AttrContext> localEnv = env.dup(that);
  2593         try {
  2594             //attribute member reference qualifier - if this is a constructor
  2595             //reference, the expected kind must be a type
  2596             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
  2598             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
  2599                 exprType = chk.checkConstructorRefType(that.expr, exprType);
  2602             if (exprType.isErroneous()) {
  2603                 //if the qualifier expression contains problems,
  2604                 //give up attribution of method reference
  2605                 result = that.type = exprType;
  2606                 return;
  2609             if (TreeInfo.isStaticSelector(that.expr, names) &&
  2610                     (that.getMode() != ReferenceMode.NEW || !that.expr.type.isRaw())) {
  2611                 //if the qualifier is a type, validate it
  2612                 chk.validate(that.expr, env);
  2615             //attrib type-arguments
  2616             List<Type> typeargtypes = List.nil();
  2617             if (that.typeargs != null) {
  2618                 typeargtypes = attribTypes(that.typeargs, localEnv);
  2621             Type target;
  2622             Type desc;
  2623             if (pt() != Type.recoveryType) {
  2624                 target = targetChecker.visit(pt(), that);
  2625                 desc = types.findDescriptorType(target);
  2626                 chk.checkFunctionalInterface(that, target);
  2627             } else {
  2628                 target = Type.recoveryType;
  2629                 desc = fallbackDescriptorType(that);
  2632             setFunctionalInfo(that, pt(), desc, target, resultInfo.checkContext.inferenceContext());
  2633             List<Type> argtypes = desc.getParameterTypes();
  2635             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult =
  2636                     rs.resolveMemberReference(that.pos(), localEnv, that,
  2637                         that.expr.type, that.name, argtypes, typeargtypes, true, rs.resolveMethodCheck);
  2639             Symbol refSym = refResult.fst;
  2640             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
  2642             if (refSym.kind != MTH) {
  2643                 boolean targetError;
  2644                 switch (refSym.kind) {
  2645                     case ABSENT_MTH:
  2646                         targetError = false;
  2647                         break;
  2648                     case WRONG_MTH:
  2649                     case WRONG_MTHS:
  2650                     case AMBIGUOUS:
  2651                     case HIDDEN:
  2652                     case STATICERR:
  2653                     case MISSING_ENCL:
  2654                         targetError = true;
  2655                         break;
  2656                     default:
  2657                         Assert.error("unexpected result kind " + refSym.kind);
  2658                         targetError = false;
  2661                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym).getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
  2662                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
  2664                 JCDiagnostic.DiagnosticType diagKind = targetError ?
  2665                         JCDiagnostic.DiagnosticType.FRAGMENT : JCDiagnostic.DiagnosticType.ERROR;
  2667                 JCDiagnostic diag = diags.create(diagKind, log.currentSource(), that,
  2668                         "invalid.mref", Kinds.kindName(that.getMode()), detailsDiag);
  2670                 if (targetError && target == Type.recoveryType) {
  2671                     //a target error doesn't make sense during recovery stage
  2672                     //as we don't know what actual parameter types are
  2673                     result = that.type = target;
  2674                     return;
  2675                 } else {
  2676                     if (targetError) {
  2677                         resultInfo.checkContext.report(that, diag);
  2678                     } else {
  2679                         log.report(diag);
  2681                     result = that.type = types.createErrorType(target);
  2682                     return;
  2686             that.sym = refSym.baseSymbol();
  2687             that.kind = lookupHelper.referenceKind(that.sym);
  2688             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
  2690             if (desc.getReturnType() == Type.recoveryType) {
  2691                 // stop here
  2692                 result = that.type = target;
  2693                 return;
  2696             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
  2698                 if (!that.kind.isUnbound() &&
  2699                         that.getMode() == ReferenceMode.INVOKE &&
  2700                         TreeInfo.isStaticSelector(that.expr, names) &&
  2701                         !that.sym.isStatic()) {
  2702                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2703                             diags.fragment("non-static.cant.be.ref", Kinds.kindName(refSym), refSym));
  2704                     result = that.type = types.createErrorType(target);
  2705                     return;
  2708                 if (that.kind.isUnbound() &&
  2709                         that.getMode() == ReferenceMode.INVOKE &&
  2710                         TreeInfo.isStaticSelector(that.expr, names) &&
  2711                         that.sym.isStatic()) {
  2712                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2713                             diags.fragment("static.method.in.unbound.lookup", Kinds.kindName(refSym), refSym));
  2714                     result = that.type = types.createErrorType(target);
  2715                     return;
  2718                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
  2719                         exprType.getTypeArguments().nonEmpty()) {
  2720                     //static ref with class type-args
  2721                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2722                             diags.fragment("static.mref.with.targs"));
  2723                     result = that.type = types.createErrorType(target);
  2724                     return;
  2727                 if (that.sym.isStatic() && !TreeInfo.isStaticSelector(that.expr, names) &&
  2728                         !that.kind.isUnbound()) {
  2729                     //no static bound mrefs
  2730                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2731                             diags.fragment("static.bound.mref"));
  2732                     result = that.type = types.createErrorType(target);
  2733                     return;
  2736                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
  2737                     // Check that super-qualified symbols are not abstract (JLS)
  2738                     rs.checkNonAbstract(that.pos(), that.sym);
  2742             that.sym = refSym.baseSymbol();
  2743             that.kind = lookupHelper.referenceKind(that.sym);
  2745             ResultInfo checkInfo =
  2746                     resultInfo.dup(newMethodTemplate(
  2747                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
  2748                         lookupHelper.argtypes,
  2749                         typeargtypes));
  2751             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
  2753             if (!refType.isErroneous()) {
  2754                 refType = types.createMethodTypeWithReturn(refType,
  2755                         adjustMethodReturnType(lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
  2758             //go ahead with standard method reference compatibility check - note that param check
  2759             //is a no-op (as this has been taken care during method applicability)
  2760             boolean isSpeculativeRound =
  2761                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
  2762             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
  2763             if (!isSpeculativeRound) {
  2764                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, target);
  2766             result = check(that, target, VAL, resultInfo);
  2767         } catch (Types.FunctionDescriptorLookupError ex) {
  2768             JCDiagnostic cause = ex.getDiagnostic();
  2769             resultInfo.checkContext.report(that, cause);
  2770             result = that.type = types.createErrorType(pt());
  2771             return;
  2774     //where
  2775         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
  2776             //if this is a constructor reference, the expected kind must be a type
  2777             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ? VAL | TYP : TYP, Type.noType);
  2781     @SuppressWarnings("fallthrough")
  2782     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
  2783         Type returnType = checkContext.inferenceContext().asFree(descriptor.getReturnType());
  2785         Type resType;
  2786         switch (tree.getMode()) {
  2787             case NEW:
  2788                 if (!tree.expr.type.isRaw()) {
  2789                     resType = tree.expr.type;
  2790                     break;
  2792             default:
  2793                 resType = refType.getReturnType();
  2796         Type incompatibleReturnType = resType;
  2798         if (returnType.hasTag(VOID)) {
  2799             incompatibleReturnType = null;
  2802         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
  2803             if (resType.isErroneous() ||
  2804                     new FunctionalReturnContext(checkContext).compatible(resType, returnType, types.noWarnings)) {
  2805                 incompatibleReturnType = null;
  2809         if (incompatibleReturnType != null) {
  2810             checkContext.report(tree, diags.fragment("incompatible.ret.type.in.mref",
  2811                     diags.fragment("inconvertible.types", resType, descriptor.getReturnType())));
  2814         if (!speculativeAttr) {
  2815             List<Type> thrownTypes = checkContext.inferenceContext().asFree(descriptor.getThrownTypes());
  2816             if (chk.unhandled(refType.getThrownTypes(), thrownTypes).nonEmpty()) {
  2817                 log.error(tree, "incompatible.thrown.types.in.mref", refType.getThrownTypes());
  2822     /**
  2823      * Set functional type info on the underlying AST. Note: as the target descriptor
  2824      * might contain inference variables, we might need to register an hook in the
  2825      * current inference context.
  2826      */
  2827     private void setFunctionalInfo(final JCFunctionalExpression fExpr, final Type pt,
  2828             final Type descriptorType, final Type primaryTarget, InferenceContext inferenceContext) {
  2829         if (inferenceContext.free(descriptorType)) {
  2830             inferenceContext.addFreeTypeListener(List.of(pt, descriptorType), new FreeTypeListener() {
  2831                 public void typesInferred(InferenceContext inferenceContext) {
  2832                     setFunctionalInfo(fExpr, pt, inferenceContext.asInstType(descriptorType),
  2833                             inferenceContext.asInstType(primaryTarget), inferenceContext);
  2835             });
  2836         } else {
  2837             ListBuffer<TypeSymbol> targets = ListBuffer.lb();
  2838             if (pt.hasTag(CLASS)) {
  2839                 if (pt.isCompound()) {
  2840                     targets.append(primaryTarget.tsym); //this goes first
  2841                     for (Type t : ((IntersectionClassType)pt()).interfaces_field) {
  2842                         if (t != primaryTarget) {
  2843                             targets.append(t.tsym);
  2846                 } else {
  2847                     targets.append(pt.tsym);
  2850             fExpr.targets = targets.toList();
  2851             fExpr.descriptorType = descriptorType;
  2855     public void visitParens(JCParens tree) {
  2856         Type owntype = attribTree(tree.expr, env, resultInfo);
  2857         result = check(tree, owntype, pkind(), resultInfo);
  2858         Symbol sym = TreeInfo.symbol(tree);
  2859         if (sym != null && (sym.kind&(TYP|PCK)) != 0)
  2860             log.error(tree.pos(), "illegal.start.of.type");
  2863     public void visitAssign(JCAssign tree) {
  2864         Type owntype = attribTree(tree.lhs, env.dup(tree), varInfo);
  2865         Type capturedType = capture(owntype);
  2866         attribExpr(tree.rhs, env, owntype);
  2867         result = check(tree, capturedType, VAL, resultInfo);
  2870     public void visitAssignop(JCAssignOp tree) {
  2871         // Attribute arguments.
  2872         Type owntype = attribTree(tree.lhs, env, varInfo);
  2873         Type operand = attribExpr(tree.rhs, env);
  2874         // Find operator.
  2875         Symbol operator = tree.operator = rs.resolveBinaryOperator(
  2876             tree.pos(), tree.getTag().noAssignOp(), env,
  2877             owntype, operand);
  2879         if (operator.kind == MTH &&
  2880                 !owntype.isErroneous() &&
  2881                 !operand.isErroneous()) {
  2882             chk.checkOperator(tree.pos(),
  2883                               (OperatorSymbol)operator,
  2884                               tree.getTag().noAssignOp(),
  2885                               owntype,
  2886                               operand);
  2887             chk.checkDivZero(tree.rhs.pos(), operator, operand);
  2888             chk.checkCastable(tree.rhs.pos(),
  2889                               operator.type.getReturnType(),
  2890                               owntype);
  2892         result = check(tree, owntype, VAL, resultInfo);
  2895     public void visitUnary(JCUnary tree) {
  2896         // Attribute arguments.
  2897         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
  2898             ? attribTree(tree.arg, env, varInfo)
  2899             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
  2901         // Find operator.
  2902         Symbol operator = tree.operator =
  2903             rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
  2905         Type owntype = types.createErrorType(tree.type);
  2906         if (operator.kind == MTH &&
  2907                 !argtype.isErroneous()) {
  2908             owntype = (tree.getTag().isIncOrDecUnaryOp())
  2909                 ? tree.arg.type
  2910                 : operator.type.getReturnType();
  2911             int opc = ((OperatorSymbol)operator).opcode;
  2913             // If the argument is constant, fold it.
  2914             if (argtype.constValue() != null) {
  2915                 Type ctype = cfolder.fold1(opc, argtype);
  2916                 if (ctype != null) {
  2917                     owntype = cfolder.coerce(ctype, owntype);
  2919                     // Remove constant types from arguments to
  2920                     // conserve space. The parser will fold concatenations
  2921                     // of string literals; the code here also
  2922                     // gets rid of intermediate results when some of the
  2923                     // operands are constant identifiers.
  2924                     if (tree.arg.type.tsym == syms.stringType.tsym) {
  2925                         tree.arg.type = syms.stringType;
  2930         result = check(tree, owntype, VAL, resultInfo);
  2933     public void visitBinary(JCBinary tree) {
  2934         // Attribute arguments.
  2935         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
  2936         Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
  2938         // Find operator.
  2939         Symbol operator = tree.operator =
  2940             rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
  2942         Type owntype = types.createErrorType(tree.type);
  2943         if (operator.kind == MTH &&
  2944                 !left.isErroneous() &&
  2945                 !right.isErroneous()) {
  2946             owntype = operator.type.getReturnType();
  2947             int opc = chk.checkOperator(tree.lhs.pos(),
  2948                                         (OperatorSymbol)operator,
  2949                                         tree.getTag(),
  2950                                         left,
  2951                                         right);
  2953             // If both arguments are constants, fold them.
  2954             if (left.constValue() != null && right.constValue() != null) {
  2955                 Type ctype = cfolder.fold2(opc, left, right);
  2956                 if (ctype != null) {
  2957                     owntype = cfolder.coerce(ctype, owntype);
  2959                     // Remove constant types from arguments to
  2960                     // conserve space. The parser will fold concatenations
  2961                     // of string literals; the code here also
  2962                     // gets rid of intermediate results when some of the
  2963                     // operands are constant identifiers.
  2964                     if (tree.lhs.type.tsym == syms.stringType.tsym) {
  2965                         tree.lhs.type = syms.stringType;
  2967                     if (tree.rhs.type.tsym == syms.stringType.tsym) {
  2968                         tree.rhs.type = syms.stringType;
  2973             // Check that argument types of a reference ==, != are
  2974             // castable to each other, (JLS???).
  2975             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
  2976                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
  2977                     log.error(tree.pos(), "incomparable.types", left, right);
  2981             chk.checkDivZero(tree.rhs.pos(), operator, right);
  2983         result = check(tree, owntype, VAL, resultInfo);
  2986     public void visitTypeCast(final JCTypeCast tree) {
  2987         Type clazztype = attribType(tree.clazz, env);
  2988         chk.validate(tree.clazz, env, false);
  2989         //a fresh environment is required for 292 inference to work properly ---
  2990         //see Infer.instantiatePolymorphicSignatureInstance()
  2991         Env<AttrContext> localEnv = env.dup(tree);
  2992         //should we propagate the target type?
  2993         final ResultInfo castInfo;
  2994         JCExpression expr = TreeInfo.skipParens(tree.expr);
  2995         boolean isPoly = expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE);
  2996         if (isPoly) {
  2997             //expression is a poly - we need to propagate target type info
  2998             castInfo = new ResultInfo(VAL, clazztype, new Check.NestedCheckContext(resultInfo.checkContext) {
  2999                 @Override
  3000                 public boolean compatible(Type found, Type req, Warner warn) {
  3001                     return types.isCastable(found, req, warn);
  3003             });
  3004         } else {
  3005             //standalone cast - target-type info is not propagated
  3006             castInfo = unknownExprInfo;
  3008         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
  3009         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
  3010         if (exprtype.constValue() != null)
  3011             owntype = cfolder.coerce(exprtype, owntype);
  3012         result = check(tree, capture(owntype), VAL, resultInfo);
  3013         if (!isPoly)
  3014             chk.checkRedundantCast(localEnv, tree);
  3017     public void visitTypeTest(JCInstanceOf tree) {
  3018         Type exprtype = chk.checkNullOrRefType(
  3019             tree.expr.pos(), attribExpr(tree.expr, env));
  3020         Type clazztype = chk.checkReifiableReferenceType(
  3021             tree.clazz.pos(), attribType(tree.clazz, env));
  3022         chk.validate(tree.clazz, env, false);
  3023         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
  3024         result = check(tree, syms.booleanType, VAL, resultInfo);
  3027     public void visitIndexed(JCArrayAccess tree) {
  3028         Type owntype = types.createErrorType(tree.type);
  3029         Type atype = attribExpr(tree.indexed, env);
  3030         attribExpr(tree.index, env, syms.intType);
  3031         if (types.isArray(atype))
  3032             owntype = types.elemtype(atype);
  3033         else if (!atype.hasTag(ERROR))
  3034             log.error(tree.pos(), "array.req.but.found", atype);
  3035         if ((pkind() & VAR) == 0) owntype = capture(owntype);
  3036         result = check(tree, owntype, VAR, resultInfo);
  3039     public void visitIdent(JCIdent tree) {
  3040         Symbol sym;
  3042         // Find symbol
  3043         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
  3044             // If we are looking for a method, the prototype `pt' will be a
  3045             // method type with the type of the call's arguments as parameters.
  3046             env.info.pendingResolutionPhase = null;
  3047             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
  3048         } else if (tree.sym != null && tree.sym.kind != VAR) {
  3049             sym = tree.sym;
  3050         } else {
  3051             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
  3053         tree.sym = sym;
  3055         // (1) Also find the environment current for the class where
  3056         //     sym is defined (`symEnv').
  3057         // Only for pre-tiger versions (1.4 and earlier):
  3058         // (2) Also determine whether we access symbol out of an anonymous
  3059         //     class in a this or super call.  This is illegal for instance
  3060         //     members since such classes don't carry a this$n link.
  3061         //     (`noOuterThisPath').
  3062         Env<AttrContext> symEnv = env;
  3063         boolean noOuterThisPath = false;
  3064         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
  3065             (sym.kind & (VAR | MTH | TYP)) != 0 &&
  3066             sym.owner.kind == TYP &&
  3067             tree.name != names._this && tree.name != names._super) {
  3069             // Find environment in which identifier is defined.
  3070             while (symEnv.outer != null &&
  3071                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
  3072                 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
  3073                     noOuterThisPath = !allowAnonOuterThis;
  3074                 symEnv = symEnv.outer;
  3078         // If symbol is a variable, ...
  3079         if (sym.kind == VAR) {
  3080             VarSymbol v = (VarSymbol)sym;
  3082             // ..., evaluate its initializer, if it has one, and check for
  3083             // illegal forward reference.
  3084             checkInit(tree, env, v, false);
  3086             // If we are expecting a variable (as opposed to a value), check
  3087             // that the variable is assignable in the current environment.
  3088             if (pkind() == VAR)
  3089                 checkAssignable(tree.pos(), v, null, env);
  3092         // In a constructor body,
  3093         // if symbol is a field or instance method, check that it is
  3094         // not accessed before the supertype constructor is called.
  3095         if ((symEnv.info.isSelfCall || noOuterThisPath) &&
  3096             (sym.kind & (VAR | MTH)) != 0 &&
  3097             sym.owner.kind == TYP &&
  3098             (sym.flags() & STATIC) == 0) {
  3099             chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
  3101         Env<AttrContext> env1 = env;
  3102         if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
  3103             // If the found symbol is inaccessible, then it is
  3104             // accessed through an enclosing instance.  Locate this
  3105             // enclosing instance:
  3106             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
  3107                 env1 = env1.outer;
  3109         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
  3112     public void visitSelect(JCFieldAccess tree) {
  3113         // Determine the expected kind of the qualifier expression.
  3114         int skind = 0;
  3115         if (tree.name == names._this || tree.name == names._super ||
  3116             tree.name == names._class)
  3118             skind = TYP;
  3119         } else {
  3120             if ((pkind() & PCK) != 0) skind = skind | PCK;
  3121             if ((pkind() & TYP) != 0) skind = skind | TYP | PCK;
  3122             if ((pkind() & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
  3125         // Attribute the qualifier expression, and determine its symbol (if any).
  3126         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Infer.anyPoly));
  3127         if ((pkind() & (PCK | TYP)) == 0)
  3128             site = capture(site); // Capture field access
  3130         // don't allow T.class T[].class, etc
  3131         if (skind == TYP) {
  3132             Type elt = site;
  3133             while (elt.hasTag(ARRAY))
  3134                 elt = ((ArrayType)elt).elemtype;
  3135             if (elt.hasTag(TYPEVAR)) {
  3136                 log.error(tree.pos(), "type.var.cant.be.deref");
  3137                 result = types.createErrorType(tree.type);
  3138                 return;
  3142         // If qualifier symbol is a type or `super', assert `selectSuper'
  3143         // for the selection. This is relevant for determining whether
  3144         // protected symbols are accessible.
  3145         Symbol sitesym = TreeInfo.symbol(tree.selected);
  3146         boolean selectSuperPrev = env.info.selectSuper;
  3147         env.info.selectSuper =
  3148             sitesym != null &&
  3149             sitesym.name == names._super;
  3151         // Determine the symbol represented by the selection.
  3152         env.info.pendingResolutionPhase = null;
  3153         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
  3154         if (sym.exists() && !isType(sym) && (pkind() & (PCK | TYP)) != 0) {
  3155             site = capture(site);
  3156             sym = selectSym(tree, sitesym, site, env, resultInfo);
  3158         boolean varArgs = env.info.lastResolveVarargs();
  3159         tree.sym = sym;
  3161         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
  3162             while (site.hasTag(TYPEVAR)) site = site.getUpperBound();
  3163             site = capture(site);
  3166         // If that symbol is a variable, ...
  3167         if (sym.kind == VAR) {
  3168             VarSymbol v = (VarSymbol)sym;
  3170             // ..., evaluate its initializer, if it has one, and check for
  3171             // illegal forward reference.
  3172             checkInit(tree, env, v, true);
  3174             // If we are expecting a variable (as opposed to a value), check
  3175             // that the variable is assignable in the current environment.
  3176             if (pkind() == VAR)
  3177                 checkAssignable(tree.pos(), v, tree.selected, env);
  3180         if (sitesym != null &&
  3181                 sitesym.kind == VAR &&
  3182                 ((VarSymbol)sitesym).isResourceVariable() &&
  3183                 sym.kind == MTH &&
  3184                 sym.name.equals(names.close) &&
  3185                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
  3186                 env.info.lint.isEnabled(LintCategory.TRY)) {
  3187             log.warning(LintCategory.TRY, tree, "try.explicit.close.call");
  3190         // Disallow selecting a type from an expression
  3191         if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
  3192             tree.type = check(tree.selected, pt(),
  3193                               sitesym == null ? VAL : sitesym.kind, new ResultInfo(TYP|PCK, pt()));
  3196         if (isType(sitesym)) {
  3197             if (sym.name == names._this) {
  3198                 // If `C' is the currently compiled class, check that
  3199                 // C.this' does not appear in a call to a super(...)
  3200                 if (env.info.isSelfCall &&
  3201                     site.tsym == env.enclClass.sym) {
  3202                     chk.earlyRefError(tree.pos(), sym);
  3204             } else {
  3205                 // Check if type-qualified fields or methods are static (JLS)
  3206                 if ((sym.flags() & STATIC) == 0 &&
  3207                     !env.next.tree.hasTag(REFERENCE) &&
  3208                     sym.name != names._super &&
  3209                     (sym.kind == VAR || sym.kind == MTH)) {
  3210                     rs.accessBase(rs.new StaticError(sym),
  3211                               tree.pos(), site, sym.name, true);
  3214         } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
  3215             // If the qualified item is not a type and the selected item is static, report
  3216             // a warning. Make allowance for the class of an array type e.g. Object[].class)
  3217             chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
  3220         // If we are selecting an instance member via a `super', ...
  3221         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
  3223             // Check that super-qualified symbols are not abstract (JLS)
  3224             rs.checkNonAbstract(tree.pos(), sym);
  3226             if (site.isRaw()) {
  3227                 // Determine argument types for site.
  3228                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
  3229                 if (site1 != null) site = site1;
  3233         env.info.selectSuper = selectSuperPrev;
  3234         result = checkId(tree, site, sym, env, resultInfo);
  3236     //where
  3237         /** Determine symbol referenced by a Select expression,
  3239          *  @param tree   The select tree.
  3240          *  @param site   The type of the selected expression,
  3241          *  @param env    The current environment.
  3242          *  @param resultInfo The current result.
  3243          */
  3244         private Symbol selectSym(JCFieldAccess tree,
  3245                                  Symbol location,
  3246                                  Type site,
  3247                                  Env<AttrContext> env,
  3248                                  ResultInfo resultInfo) {
  3249             DiagnosticPosition pos = tree.pos();
  3250             Name name = tree.name;
  3251             switch (site.getTag()) {
  3252             case PACKAGE:
  3253                 return rs.accessBase(
  3254                     rs.findIdentInPackage(env, site.tsym, name, resultInfo.pkind),
  3255                     pos, location, site, name, true);
  3256             case ARRAY:
  3257             case CLASS:
  3258                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
  3259                     return rs.resolveQualifiedMethod(
  3260                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
  3261                 } else if (name == names._this || name == names._super) {
  3262                     return rs.resolveSelf(pos, env, site.tsym, name);
  3263                 } else if (name == names._class) {
  3264                     // In this case, we have already made sure in
  3265                     // visitSelect that qualifier expression is a type.
  3266                     Type t = syms.classType;
  3267                     List<Type> typeargs = allowGenerics
  3268                         ? List.of(types.erasure(site))
  3269                         : List.<Type>nil();
  3270                     t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
  3271                     return new VarSymbol(
  3272                         STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
  3273                 } else {
  3274                     // We are seeing a plain identifier as selector.
  3275                     Symbol sym = rs.findIdentInType(env, site, name, resultInfo.pkind);
  3276                     if ((resultInfo.pkind & ERRONEOUS) == 0)
  3277                         sym = rs.accessBase(sym, pos, location, site, name, true);
  3278                     return sym;
  3280             case WILDCARD:
  3281                 throw new AssertionError(tree);
  3282             case TYPEVAR:
  3283                 // Normally, site.getUpperBound() shouldn't be null.
  3284                 // It should only happen during memberEnter/attribBase
  3285                 // when determining the super type which *must* beac
  3286                 // done before attributing the type variables.  In
  3287                 // other words, we are seeing this illegal program:
  3288                 // class B<T> extends A<T.foo> {}
  3289                 Symbol sym = (site.getUpperBound() != null)
  3290                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
  3291                     : null;
  3292                 if (sym == null) {
  3293                     log.error(pos, "type.var.cant.be.deref");
  3294                     return syms.errSymbol;
  3295                 } else {
  3296                     Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
  3297                         rs.new AccessError(env, site, sym) :
  3298                                 sym;
  3299                     rs.accessBase(sym2, pos, location, site, name, true);
  3300                     return sym;
  3302             case ERROR:
  3303                 // preserve identifier names through errors
  3304                 return types.createErrorType(name, site.tsym, site).tsym;
  3305             default:
  3306                 // The qualifier expression is of a primitive type -- only
  3307                 // .class is allowed for these.
  3308                 if (name == names._class) {
  3309                     // In this case, we have already made sure in Select that
  3310                     // qualifier expression is a type.
  3311                     Type t = syms.classType;
  3312                     Type arg = types.boxedClass(site).type;
  3313                     t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
  3314                     return new VarSymbol(
  3315                         STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
  3316                 } else {
  3317                     log.error(pos, "cant.deref", site);
  3318                     return syms.errSymbol;
  3323         /** Determine type of identifier or select expression and check that
  3324          *  (1) the referenced symbol is not deprecated
  3325          *  (2) the symbol's type is safe (@see checkSafe)
  3326          *  (3) if symbol is a variable, check that its type and kind are
  3327          *      compatible with the prototype and protokind.
  3328          *  (4) if symbol is an instance field of a raw type,
  3329          *      which is being assigned to, issue an unchecked warning if its
  3330          *      type changes under erasure.
  3331          *  (5) if symbol is an instance method of a raw type, issue an
  3332          *      unchecked warning if its argument types change under erasure.
  3333          *  If checks succeed:
  3334          *    If symbol is a constant, return its constant type
  3335          *    else if symbol is a method, return its result type
  3336          *    otherwise return its type.
  3337          *  Otherwise return errType.
  3339          *  @param tree       The syntax tree representing the identifier
  3340          *  @param site       If this is a select, the type of the selected
  3341          *                    expression, otherwise the type of the current class.
  3342          *  @param sym        The symbol representing the identifier.
  3343          *  @param env        The current environment.
  3344          *  @param resultInfo    The expected result
  3345          */
  3346         Type checkId(JCTree tree,
  3347                      Type site,
  3348                      Symbol sym,
  3349                      Env<AttrContext> env,
  3350                      ResultInfo resultInfo) {
  3351             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
  3352                     checkMethodId(tree, site, sym, env, resultInfo) :
  3353                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
  3356         Type checkMethodId(JCTree tree,
  3357                      Type site,
  3358                      Symbol sym,
  3359                      Env<AttrContext> env,
  3360                      ResultInfo resultInfo) {
  3361             boolean isPolymorhicSignature =
  3362                 sym.kind == MTH && ((MethodSymbol)sym.baseSymbol()).isSignaturePolymorphic(types);
  3363             return isPolymorhicSignature ?
  3364                     checkSigPolyMethodId(tree, site, sym, env, resultInfo) :
  3365                     checkMethodIdInternal(tree, site, sym, env, resultInfo);
  3368         Type checkSigPolyMethodId(JCTree tree,
  3369                      Type site,
  3370                      Symbol sym,
  3371                      Env<AttrContext> env,
  3372                      ResultInfo resultInfo) {
  3373             //recover original symbol for signature polymorphic methods
  3374             checkMethodIdInternal(tree, site, sym.baseSymbol(), env, resultInfo);
  3375             env.info.pendingResolutionPhase = Resolve.MethodResolutionPhase.BASIC;
  3376             return sym.type;
  3379         Type checkMethodIdInternal(JCTree tree,
  3380                      Type site,
  3381                      Symbol sym,
  3382                      Env<AttrContext> env,
  3383                      ResultInfo resultInfo) {
  3384             Type pt = resultInfo.pt.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, sym, env.info.pendingResolutionPhase));
  3385             Type owntype = checkIdInternal(tree, site, sym, pt, env, resultInfo);
  3386             resultInfo.pt.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
  3387             return owntype;
  3390         Type checkIdInternal(JCTree tree,
  3391                      Type site,
  3392                      Symbol sym,
  3393                      Type pt,
  3394                      Env<AttrContext> env,
  3395                      ResultInfo resultInfo) {
  3396             if (pt.isErroneous()) {
  3397                 return types.createErrorType(site);
  3399             Type owntype; // The computed type of this identifier occurrence.
  3400             switch (sym.kind) {
  3401             case TYP:
  3402                 // For types, the computed type equals the symbol's type,
  3403                 // except for two situations:
  3404                 owntype = sym.type;
  3405                 if (owntype.hasTag(CLASS)) {
  3406                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
  3407                     Type ownOuter = owntype.getEnclosingType();
  3409                     // (a) If the symbol's type is parameterized, erase it
  3410                     // because no type parameters were given.
  3411                     // We recover generic outer type later in visitTypeApply.
  3412                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
  3413                         owntype = types.erasure(owntype);
  3416                     // (b) If the symbol's type is an inner class, then
  3417                     // we have to interpret its outer type as a superclass
  3418                     // of the site type. Example:
  3419                     //
  3420                     // class Tree<A> { class Visitor { ... } }
  3421                     // class PointTree extends Tree<Point> { ... }
  3422                     // ...PointTree.Visitor...
  3423                     //
  3424                     // Then the type of the last expression above is
  3425                     // Tree<Point>.Visitor.
  3426                     else if (ownOuter.hasTag(CLASS) && site != ownOuter) {
  3427                         Type normOuter = site;
  3428                         if (normOuter.hasTag(CLASS)) {
  3429                             normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
  3430                             if (site.isAnnotated()) {
  3431                                 // Propagate any type annotations.
  3432                                 // TODO: should asEnclosingSuper do this?
  3433                                 // Note that the type annotations in site will be updated
  3434                                 // by annotateType. Therefore, modify site instead
  3435                                 // of creating a new AnnotatedType.
  3436                                 ((AnnotatedType)site).underlyingType = normOuter;
  3437                                 normOuter = site;
  3440                         if (normOuter == null) // perhaps from an import
  3441                             normOuter = types.erasure(ownOuter);
  3442                         if (normOuter != ownOuter)
  3443                             owntype = new ClassType(
  3444                                 normOuter, List.<Type>nil(), owntype.tsym);
  3447                 break;
  3448             case VAR:
  3449                 VarSymbol v = (VarSymbol)sym;
  3450                 // Test (4): if symbol is an instance field of a raw type,
  3451                 // which is being assigned to, issue an unchecked warning if
  3452                 // its type changes under erasure.
  3453                 if (allowGenerics &&
  3454                     resultInfo.pkind == VAR &&
  3455                     v.owner.kind == TYP &&
  3456                     (v.flags() & STATIC) == 0 &&
  3457                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
  3458                     Type s = types.asOuterSuper(site, v.owner);
  3459                     if (s != null &&
  3460                         s.isRaw() &&
  3461                         !types.isSameType(v.type, v.erasure(types))) {
  3462                         chk.warnUnchecked(tree.pos(),
  3463                                           "unchecked.assign.to.var",
  3464                                           v, s);
  3467                 // The computed type of a variable is the type of the
  3468                 // variable symbol, taken as a member of the site type.
  3469                 owntype = (sym.owner.kind == TYP &&
  3470                            sym.name != names._this && sym.name != names._super)
  3471                     ? types.memberType(site, sym)
  3472                     : sym.type;
  3474                 // If the variable is a constant, record constant value in
  3475                 // computed type.
  3476                 if (v.getConstValue() != null && isStaticReference(tree))
  3477                     owntype = owntype.constType(v.getConstValue());
  3479                 if (resultInfo.pkind == VAL) {
  3480                     owntype = capture(owntype); // capture "names as expressions"
  3482                 break;
  3483             case MTH: {
  3484                 owntype = checkMethod(site, sym,
  3485                         new ResultInfo(VAL, resultInfo.pt.getReturnType(), resultInfo.checkContext),
  3486                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
  3487                         resultInfo.pt.getTypeArguments());
  3488                 break;
  3490             case PCK: case ERR:
  3491                 owntype = sym.type;
  3492                 break;
  3493             default:
  3494                 throw new AssertionError("unexpected kind: " + sym.kind +
  3495                                          " in tree " + tree);
  3498             // Test (1): emit a `deprecation' warning if symbol is deprecated.
  3499             // (for constructors, the error was given when the constructor was
  3500             // resolved)
  3502             if (sym.name != names.init) {
  3503                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
  3504                 chk.checkSunAPI(tree.pos(), sym);
  3505                 chk.checkProfile(tree.pos(), sym);
  3508             // Test (3): if symbol is a variable, check that its type and
  3509             // kind are compatible with the prototype and protokind.
  3510             return check(tree, owntype, sym.kind, resultInfo);
  3513         /** Check that variable is initialized and evaluate the variable's
  3514          *  initializer, if not yet done. Also check that variable is not
  3515          *  referenced before it is defined.
  3516          *  @param tree    The tree making up the variable reference.
  3517          *  @param env     The current environment.
  3518          *  @param v       The variable's symbol.
  3519          */
  3520         private void checkInit(JCTree tree,
  3521                                Env<AttrContext> env,
  3522                                VarSymbol v,
  3523                                boolean onlyWarning) {
  3524 //          System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
  3525 //                             tree.pos + " " + v.pos + " " +
  3526 //                             Resolve.isStatic(env));//DEBUG
  3528             // A forward reference is diagnosed if the declaration position
  3529             // of the variable is greater than the current tree position
  3530             // and the tree and variable definition occur in the same class
  3531             // definition.  Note that writes don't count as references.
  3532             // This check applies only to class and instance
  3533             // variables.  Local variables follow different scope rules,
  3534             // and are subject to definite assignment checking.
  3535             if ((env.info.enclVar == v || v.pos > tree.pos) &&
  3536                 v.owner.kind == TYP &&
  3537                 canOwnInitializer(owner(env)) &&
  3538                 v.owner == env.info.scope.owner.enclClass() &&
  3539                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
  3540                 (!env.tree.hasTag(ASSIGN) ||
  3541                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
  3542                 String suffix = (env.info.enclVar == v) ?
  3543                                 "self.ref" : "forward.ref";
  3544                 if (!onlyWarning || isStaticEnumField(v)) {
  3545                     log.error(tree.pos(), "illegal." + suffix);
  3546                 } else if (useBeforeDeclarationWarning) {
  3547                     log.warning(tree.pos(), suffix, v);
  3551             v.getConstValue(); // ensure initializer is evaluated
  3553             checkEnumInitializer(tree, env, v);
  3556         /**
  3557          * Check for illegal references to static members of enum.  In
  3558          * an enum type, constructors and initializers may not
  3559          * reference its static members unless they are constant.
  3561          * @param tree    The tree making up the variable reference.
  3562          * @param env     The current environment.
  3563          * @param v       The variable's symbol.
  3564          * @jls  section 8.9 Enums
  3565          */
  3566         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
  3567             // JLS:
  3568             //
  3569             // "It is a compile-time error to reference a static field
  3570             // of an enum type that is not a compile-time constant
  3571             // (15.28) from constructors, instance initializer blocks,
  3572             // or instance variable initializer expressions of that
  3573             // type. It is a compile-time error for the constructors,
  3574             // instance initializer blocks, or instance variable
  3575             // initializer expressions of an enum constant e to refer
  3576             // to itself or to an enum constant of the same type that
  3577             // is declared to the right of e."
  3578             if (isStaticEnumField(v)) {
  3579                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
  3581                 if (enclClass == null || enclClass.owner == null)
  3582                     return;
  3584                 // See if the enclosing class is the enum (or a
  3585                 // subclass thereof) declaring v.  If not, this
  3586                 // reference is OK.
  3587                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
  3588                     return;
  3590                 // If the reference isn't from an initializer, then
  3591                 // the reference is OK.
  3592                 if (!Resolve.isInitializer(env))
  3593                     return;
  3595                 log.error(tree.pos(), "illegal.enum.static.ref");
  3599         /** Is the given symbol a static, non-constant field of an Enum?
  3600          *  Note: enum literals should not be regarded as such
  3601          */
  3602         private boolean isStaticEnumField(VarSymbol v) {
  3603             return Flags.isEnum(v.owner) &&
  3604                    Flags.isStatic(v) &&
  3605                    !Flags.isConstant(v) &&
  3606                    v.name != names._class;
  3609         /** Can the given symbol be the owner of code which forms part
  3610          *  if class initialization? This is the case if the symbol is
  3611          *  a type or field, or if the symbol is the synthetic method.
  3612          *  owning a block.
  3613          */
  3614         private boolean canOwnInitializer(Symbol sym) {
  3615             return
  3616                 (sym.kind & (VAR | TYP)) != 0 ||
  3617                 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
  3620     Warner noteWarner = new Warner();
  3622     /**
  3623      * Check that method arguments conform to its instantiation.
  3624      **/
  3625     public Type checkMethod(Type site,
  3626                             Symbol sym,
  3627                             ResultInfo resultInfo,
  3628                             Env<AttrContext> env,
  3629                             final List<JCExpression> argtrees,
  3630                             List<Type> argtypes,
  3631                             List<Type> typeargtypes) {
  3632         // Test (5): if symbol is an instance method of a raw type, issue
  3633         // an unchecked warning if its argument types change under erasure.
  3634         if (allowGenerics &&
  3635             (sym.flags() & STATIC) == 0 &&
  3636             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
  3637             Type s = types.asOuterSuper(site, sym.owner);
  3638             if (s != null && s.isRaw() &&
  3639                 !types.isSameTypes(sym.type.getParameterTypes(),
  3640                                    sym.erasure(types).getParameterTypes())) {
  3641                 chk.warnUnchecked(env.tree.pos(),
  3642                                   "unchecked.call.mbr.of.raw.type",
  3643                                   sym, s);
  3647         if (env.info.defaultSuperCallSite != null) {
  3648             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
  3649                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
  3650                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
  3651                 List<MethodSymbol> icand_sup =
  3652                         types.interfaceCandidates(sup, (MethodSymbol)sym);
  3653                 if (icand_sup.nonEmpty() &&
  3654                         icand_sup.head != sym &&
  3655                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
  3656                     log.error(env.tree.pos(), "illegal.default.super.call", env.info.defaultSuperCallSite,
  3657                         diags.fragment("overridden.default", sym, sup));
  3658                     break;
  3661             env.info.defaultSuperCallSite = null;
  3664         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
  3665             JCMethodInvocation app = (JCMethodInvocation)env.tree;
  3666             if (app.meth.hasTag(SELECT) &&
  3667                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
  3668                 log.error(env.tree.pos(), "illegal.static.intf.meth.call", site);
  3672         // Compute the identifier's instantiated type.
  3673         // For methods, we need to compute the instance type by
  3674         // Resolve.instantiate from the symbol's type as well as
  3675         // any type arguments and value arguments.
  3676         noteWarner.clear();
  3677         try {
  3678             Type owntype = rs.checkMethod(
  3679                     env,
  3680                     site,
  3681                     sym,
  3682                     resultInfo,
  3683                     argtypes,
  3684                     typeargtypes,
  3685                     noteWarner);
  3687             return chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
  3688                     noteWarner.hasNonSilentLint(LintCategory.UNCHECKED));
  3689         } catch (Infer.InferenceException ex) {
  3690             //invalid target type - propagate exception outwards or report error
  3691             //depending on the current check context
  3692             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
  3693             return types.createErrorType(site);
  3694         } catch (Resolve.InapplicableMethodException ex) {
  3695             Assert.error(ex.getDiagnostic().getMessage(Locale.getDefault()));
  3696             return null;
  3700     public void visitLiteral(JCLiteral tree) {
  3701         result = check(
  3702             tree, litType(tree.typetag).constType(tree.value), VAL, resultInfo);
  3704     //where
  3705     /** Return the type of a literal with given type tag.
  3706      */
  3707     Type litType(TypeTag tag) {
  3708         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
  3711     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
  3712         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], TYP, resultInfo);
  3715     public void visitTypeArray(JCArrayTypeTree tree) {
  3716         Type etype = attribType(tree.elemtype, env);
  3717         Type type = new ArrayType(etype, syms.arrayClass);
  3718         result = check(tree, type, TYP, resultInfo);
  3721     /** Visitor method for parameterized types.
  3722      *  Bound checking is left until later, since types are attributed
  3723      *  before supertype structure is completely known
  3724      */
  3725     public void visitTypeApply(JCTypeApply tree) {
  3726         Type owntype = types.createErrorType(tree.type);
  3728         // Attribute functor part of application and make sure it's a class.
  3729         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
  3731         // Attribute type parameters
  3732         List<Type> actuals = attribTypes(tree.arguments, env);
  3734         if (clazztype.hasTag(CLASS)) {
  3735             List<Type> formals = clazztype.tsym.type.getTypeArguments();
  3736             if (actuals.isEmpty()) //diamond
  3737                 actuals = formals;
  3739             if (actuals.length() == formals.length()) {
  3740                 List<Type> a = actuals;
  3741                 List<Type> f = formals;
  3742                 while (a.nonEmpty()) {
  3743                     a.head = a.head.withTypeVar(f.head);
  3744                     a = a.tail;
  3745                     f = f.tail;
  3747                 // Compute the proper generic outer
  3748                 Type clazzOuter = clazztype.getEnclosingType();
  3749                 if (clazzOuter.hasTag(CLASS)) {
  3750                     Type site;
  3751                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
  3752                     if (clazz.hasTag(IDENT)) {
  3753                         site = env.enclClass.sym.type;
  3754                     } else if (clazz.hasTag(SELECT)) {
  3755                         site = ((JCFieldAccess) clazz).selected.type;
  3756                     } else throw new AssertionError(""+tree);
  3757                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
  3758                         if (site.hasTag(CLASS))
  3759                             site = types.asOuterSuper(site, clazzOuter.tsym);
  3760                         if (site == null)
  3761                             site = types.erasure(clazzOuter);
  3762                         clazzOuter = site;
  3765                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
  3766             } else {
  3767                 if (formals.length() != 0) {
  3768                     log.error(tree.pos(), "wrong.number.type.args",
  3769                               Integer.toString(formals.length()));
  3770                 } else {
  3771                     log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
  3773                 owntype = types.createErrorType(tree.type);
  3776         result = check(tree, owntype, TYP, resultInfo);
  3779     public void visitTypeUnion(JCTypeUnion tree) {
  3780         ListBuffer<Type> multicatchTypes = ListBuffer.lb();
  3781         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
  3782         for (JCExpression typeTree : tree.alternatives) {
  3783             Type ctype = attribType(typeTree, env);
  3784             ctype = chk.checkType(typeTree.pos(),
  3785                           chk.checkClassType(typeTree.pos(), ctype),
  3786                           syms.throwableType);
  3787             if (!ctype.isErroneous()) {
  3788                 //check that alternatives of a union type are pairwise
  3789                 //unrelated w.r.t. subtyping
  3790                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
  3791                     for (Type t : multicatchTypes) {
  3792                         boolean sub = types.isSubtype(ctype, t);
  3793                         boolean sup = types.isSubtype(t, ctype);
  3794                         if (sub || sup) {
  3795                             //assume 'a' <: 'b'
  3796                             Type a = sub ? ctype : t;
  3797                             Type b = sub ? t : ctype;
  3798                             log.error(typeTree.pos(), "multicatch.types.must.be.disjoint", a, b);
  3802                 multicatchTypes.append(ctype);
  3803                 if (all_multicatchTypes != null)
  3804                     all_multicatchTypes.append(ctype);
  3805             } else {
  3806                 if (all_multicatchTypes == null) {
  3807                     all_multicatchTypes = ListBuffer.lb();
  3808                     all_multicatchTypes.appendList(multicatchTypes);
  3810                 all_multicatchTypes.append(ctype);
  3813         Type t = check(tree, types.lub(multicatchTypes.toList()), TYP, resultInfo);
  3814         if (t.hasTag(CLASS)) {
  3815             List<Type> alternatives =
  3816                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
  3817             t = new UnionClassType((ClassType) t, alternatives);
  3819         tree.type = result = t;
  3822     public void visitTypeIntersection(JCTypeIntersection tree) {
  3823         attribTypes(tree.bounds, env);
  3824         tree.type = result = checkIntersection(tree, tree.bounds);
  3827     public void visitTypeParameter(JCTypeParameter tree) {
  3828         TypeVar typeVar = (TypeVar) tree.type;
  3830         if (tree.annotations != null && tree.annotations.nonEmpty()) {
  3831             AnnotatedType antype = new AnnotatedType(typeVar);
  3832             annotateType(antype, tree.annotations);
  3833             tree.type = antype;
  3836         if (!typeVar.bound.isErroneous()) {
  3837             //fixup type-parameter bound computed in 'attribTypeVariables'
  3838             typeVar.bound = checkIntersection(tree, tree.bounds);
  3842     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
  3843         Set<Type> boundSet = new HashSet<Type>();
  3844         if (bounds.nonEmpty()) {
  3845             // accept class or interface or typevar as first bound.
  3846             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
  3847             boundSet.add(types.erasure(bounds.head.type));
  3848             if (bounds.head.type.isErroneous()) {
  3849                 return bounds.head.type;
  3851             else if (bounds.head.type.hasTag(TYPEVAR)) {
  3852                 // if first bound was a typevar, do not accept further bounds.
  3853                 if (bounds.tail.nonEmpty()) {
  3854                     log.error(bounds.tail.head.pos(),
  3855                               "type.var.may.not.be.followed.by.other.bounds");
  3856                     return bounds.head.type;
  3858             } else {
  3859                 // if first bound was a class or interface, accept only interfaces
  3860                 // as further bounds.
  3861                 for (JCExpression bound : bounds.tail) {
  3862                     bound.type = checkBase(bound.type, bound, env, false, true, false);
  3863                     if (bound.type.isErroneous()) {
  3864                         bounds = List.of(bound);
  3866                     else if (bound.type.hasTag(CLASS)) {
  3867                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
  3873         if (bounds.length() == 0) {
  3874             return syms.objectType;
  3875         } else if (bounds.length() == 1) {
  3876             return bounds.head.type;
  3877         } else {
  3878             Type owntype = types.makeCompoundType(TreeInfo.types(bounds));
  3879             if (tree.hasTag(TYPEINTERSECTION)) {
  3880                 ((IntersectionClassType)owntype).intersectionKind =
  3881                         IntersectionClassType.IntersectionKind.EXPLICIT;
  3883             // ... the variable's bound is a class type flagged COMPOUND
  3884             // (see comment for TypeVar.bound).
  3885             // In this case, generate a class tree that represents the
  3886             // bound class, ...
  3887             JCExpression extending;
  3888             List<JCExpression> implementing;
  3889             if (!bounds.head.type.isInterface()) {
  3890                 extending = bounds.head;
  3891                 implementing = bounds.tail;
  3892             } else {
  3893                 extending = null;
  3894                 implementing = bounds;
  3896             JCClassDecl cd = make.at(tree).ClassDef(
  3897                 make.Modifiers(PUBLIC | ABSTRACT),
  3898                 names.empty, List.<JCTypeParameter>nil(),
  3899                 extending, implementing, List.<JCTree>nil());
  3901             ClassSymbol c = (ClassSymbol)owntype.tsym;
  3902             Assert.check((c.flags() & COMPOUND) != 0);
  3903             cd.sym = c;
  3904             c.sourcefile = env.toplevel.sourcefile;
  3906             // ... and attribute the bound class
  3907             c.flags_field |= UNATTRIBUTED;
  3908             Env<AttrContext> cenv = enter.classEnv(cd, env);
  3909             enter.typeEnvs.put(c, cenv);
  3910             attribClass(c);
  3911             return owntype;
  3915     public void visitWildcard(JCWildcard tree) {
  3916         //- System.err.println("visitWildcard("+tree+");");//DEBUG
  3917         Type type = (tree.kind.kind == BoundKind.UNBOUND)
  3918             ? syms.objectType
  3919             : attribType(tree.inner, env);
  3920         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
  3921                                               tree.kind.kind,
  3922                                               syms.boundClass),
  3923                        TYP, resultInfo);
  3926     public void visitAnnotation(JCAnnotation tree) {
  3927         log.error(tree.pos(), "annotation.not.valid.for.type", pt());
  3928         result = tree.type = syms.errType;
  3931     public void visitAnnotatedType(JCAnnotatedType tree) {
  3932         Type underlyingType = attribType(tree.getUnderlyingType(), env);
  3933         this.attribAnnotationTypes(tree.annotations, env);
  3934         AnnotatedType antype = new AnnotatedType(underlyingType);
  3935         annotateType(antype, tree.annotations);
  3936         result = tree.type = antype;
  3939     /**
  3940      * Apply the annotations to the particular type.
  3941      */
  3942     public void annotateType(final AnnotatedType type, final List<JCAnnotation> annotations) {
  3943         if (annotations.isEmpty())
  3944             return;
  3945         annotate.typeAnnotation(new Annotate.Annotator() {
  3946             @Override
  3947             public String toString() {
  3948                 return "annotate " + annotations + " onto " + type;
  3950             @Override
  3951             public void enterAnnotation() {
  3952                 List<Attribute.TypeCompound> compounds = fromAnnotations(annotations);
  3953                 type.typeAnnotations = compounds;
  3955         });
  3958     private static List<Attribute.TypeCompound> fromAnnotations(List<JCAnnotation> annotations) {
  3959         if (annotations.isEmpty())
  3960             return List.nil();
  3962         ListBuffer<Attribute.TypeCompound> buf = ListBuffer.lb();
  3963         for (JCAnnotation anno : annotations) {
  3964             buf.append((Attribute.TypeCompound) anno.attribute);
  3966         return buf.toList();
  3969     public void visitErroneous(JCErroneous tree) {
  3970         if (tree.errs != null)
  3971             for (JCTree err : tree.errs)
  3972                 attribTree(err, env, new ResultInfo(ERR, pt()));
  3973         result = tree.type = syms.errType;
  3976     /** Default visitor method for all other trees.
  3977      */
  3978     public void visitTree(JCTree tree) {
  3979         throw new AssertionError();
  3982     /**
  3983      * Attribute an env for either a top level tree or class declaration.
  3984      */
  3985     public void attrib(Env<AttrContext> env) {
  3986         if (env.tree.hasTag(TOPLEVEL))
  3987             attribTopLevel(env);
  3988         else
  3989             attribClass(env.tree.pos(), env.enclClass.sym);
  3992     /**
  3993      * Attribute a top level tree. These trees are encountered when the
  3994      * package declaration has annotations.
  3995      */
  3996     public void attribTopLevel(Env<AttrContext> env) {
  3997         JCCompilationUnit toplevel = env.toplevel;
  3998         try {
  3999             annotate.flush();
  4000             chk.validateAnnotations(toplevel.packageAnnotations, toplevel.packge);
  4001         } catch (CompletionFailure ex) {
  4002             chk.completionError(toplevel.pos(), ex);
  4006     /** Main method: attribute class definition associated with given class symbol.
  4007      *  reporting completion failures at the given position.
  4008      *  @param pos The source position at which completion errors are to be
  4009      *             reported.
  4010      *  @param c   The class symbol whose definition will be attributed.
  4011      */
  4012     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
  4013         try {
  4014             annotate.flush();
  4015             attribClass(c);
  4016         } catch (CompletionFailure ex) {
  4017             chk.completionError(pos, ex);
  4021     /** Attribute class definition associated with given class symbol.
  4022      *  @param c   The class symbol whose definition will be attributed.
  4023      */
  4024     void attribClass(ClassSymbol c) throws CompletionFailure {
  4025         if (c.type.hasTag(ERROR)) return;
  4027         // Check for cycles in the inheritance graph, which can arise from
  4028         // ill-formed class files.
  4029         chk.checkNonCyclic(null, c.type);
  4031         Type st = types.supertype(c.type);
  4032         if ((c.flags_field & Flags.COMPOUND) == 0) {
  4033             // First, attribute superclass.
  4034             if (st.hasTag(CLASS))
  4035                 attribClass((ClassSymbol)st.tsym);
  4037             // Next attribute owner, if it is a class.
  4038             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
  4039                 attribClass((ClassSymbol)c.owner);
  4042         // The previous operations might have attributed the current class
  4043         // if there was a cycle. So we test first whether the class is still
  4044         // UNATTRIBUTED.
  4045         if ((c.flags_field & UNATTRIBUTED) != 0) {
  4046             c.flags_field &= ~UNATTRIBUTED;
  4048             // Get environment current at the point of class definition.
  4049             Env<AttrContext> env = enter.typeEnvs.get(c);
  4051             // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
  4052             // because the annotations were not available at the time the env was created. Therefore,
  4053             // we look up the environment chain for the first enclosing environment for which the
  4054             // lint value is set. Typically, this is the parent env, but might be further if there
  4055             // are any envs created as a result of TypeParameter nodes.
  4056             Env<AttrContext> lintEnv = env;
  4057             while (lintEnv.info.lint == null)
  4058                 lintEnv = lintEnv.next;
  4060             // Having found the enclosing lint value, we can initialize the lint value for this class
  4061             env.info.lint = lintEnv.info.lint.augment(c.annotations, c.flags());
  4063             Lint prevLint = chk.setLint(env.info.lint);
  4064             JavaFileObject prev = log.useSource(c.sourcefile);
  4065             ResultInfo prevReturnRes = env.info.returnResult;
  4067             try {
  4068                 env.info.returnResult = null;
  4069                 // java.lang.Enum may not be subclassed by a non-enum
  4070                 if (st.tsym == syms.enumSym &&
  4071                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
  4072                     log.error(env.tree.pos(), "enum.no.subclassing");
  4074                 // Enums may not be extended by source-level classes
  4075                 if (st.tsym != null &&
  4076                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
  4077                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
  4078                     log.error(env.tree.pos(), "enum.types.not.extensible");
  4080                 attribClassBody(env, c);
  4082                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
  4083                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
  4084             } finally {
  4085                 env.info.returnResult = prevReturnRes;
  4086                 log.useSource(prev);
  4087                 chk.setLint(prevLint);
  4093     public void visitImport(JCImport tree) {
  4094         // nothing to do
  4097     /** Finish the attribution of a class. */
  4098     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
  4099         JCClassDecl tree = (JCClassDecl)env.tree;
  4100         Assert.check(c == tree.sym);
  4102         // Validate annotations
  4103         chk.validateAnnotations(tree.mods.annotations, c);
  4105         // Validate type parameters, supertype and interfaces.
  4106         attribStats(tree.typarams, env);
  4107         if (!c.isAnonymous()) {
  4108             //already checked if anonymous
  4109             chk.validate(tree.typarams, env);
  4110             chk.validate(tree.extending, env);
  4111             chk.validate(tree.implementing, env);
  4114         // If this is a non-abstract class, check that it has no abstract
  4115         // methods or unimplemented methods of an implemented interface.
  4116         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
  4117             if (!relax)
  4118                 chk.checkAllDefined(tree.pos(), c);
  4121         if ((c.flags() & ANNOTATION) != 0) {
  4122             if (tree.implementing.nonEmpty())
  4123                 log.error(tree.implementing.head.pos(),
  4124                           "cant.extend.intf.annotation");
  4125             if (tree.typarams.nonEmpty())
  4126                 log.error(tree.typarams.head.pos(),
  4127                           "intf.annotation.cant.have.type.params");
  4129             // If this annotation has a @Repeatable, validate
  4130             Attribute.Compound repeatable = c.attribute(syms.repeatableType.tsym);
  4131             if (repeatable != null) {
  4132                 // get diagnostic position for error reporting
  4133                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
  4134                 Assert.checkNonNull(cbPos);
  4136                 chk.validateRepeatable(c, repeatable, cbPos);
  4138         } else {
  4139             // Check that all extended classes and interfaces
  4140             // are compatible (i.e. no two define methods with same arguments
  4141             // yet different return types).  (JLS 8.4.6.3)
  4142             chk.checkCompatibleSupertypes(tree.pos(), c.type);
  4143             if (allowDefaultMethods) {
  4144                 chk.checkDefaultMethodClashes(tree.pos(), c.type);
  4148         // Check that class does not import the same parameterized interface
  4149         // with two different argument lists.
  4150         chk.checkClassBounds(tree.pos(), c.type);
  4152         tree.type = c.type;
  4154         for (List<JCTypeParameter> l = tree.typarams;
  4155              l.nonEmpty(); l = l.tail) {
  4156              Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope);
  4159         // Check that a generic class doesn't extend Throwable
  4160         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
  4161             log.error(tree.extending.pos(), "generic.throwable");
  4163         // Check that all methods which implement some
  4164         // method conform to the method they implement.
  4165         chk.checkImplementations(tree);
  4167         //check that a resource implementing AutoCloseable cannot throw InterruptedException
  4168         checkAutoCloseable(tree.pos(), env, c.type);
  4170         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
  4171             // Attribute declaration
  4172             attribStat(l.head, env);
  4173             // Check that declarations in inner classes are not static (JLS 8.1.2)
  4174             // Make an exception for static constants.
  4175             if (c.owner.kind != PCK &&
  4176                 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
  4177                 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
  4178                 Symbol sym = null;
  4179                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
  4180                 if (sym == null ||
  4181                     sym.kind != VAR ||
  4182                     ((VarSymbol) sym).getConstValue() == null)
  4183                     log.error(l.head.pos(), "icls.cant.have.static.decl", c);
  4187         // Check for cycles among non-initial constructors.
  4188         chk.checkCyclicConstructors(tree);
  4190         // Check for cycles among annotation elements.
  4191         chk.checkNonCyclicElements(tree);
  4193         // Check for proper use of serialVersionUID
  4194         if (env.info.lint.isEnabled(LintCategory.SERIAL) &&
  4195             isSerializable(c) &&
  4196             (c.flags() & Flags.ENUM) == 0 &&
  4197             (c.flags() & ABSTRACT) == 0) {
  4198             checkSerialVersionUID(tree, c);
  4201         // Correctly organize the postions of the type annotations
  4202         TypeAnnotations.organizeTypeAnnotationsBodies(this.syms, this.names, this.log, tree);
  4204         // Check type annotations applicability rules
  4205         validateTypeAnnotations(tree);
  4207         // where
  4208         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
  4209         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
  4210             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
  4211                 if (types.isSameType(al.head.annotationType.type, t))
  4212                     return al.head.pos();
  4215             return null;
  4218         /** check if a class is a subtype of Serializable, if that is available. */
  4219         private boolean isSerializable(ClassSymbol c) {
  4220             try {
  4221                 syms.serializableType.complete();
  4223             catch (CompletionFailure e) {
  4224                 return false;
  4226             return types.isSubtype(c.type, syms.serializableType);
  4229         /** Check that an appropriate serialVersionUID member is defined. */
  4230         private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
  4232             // check for presence of serialVersionUID
  4233             Scope.Entry e = c.members().lookup(names.serialVersionUID);
  4234             while (e.scope != null && e.sym.kind != VAR) e = e.next();
  4235             if (e.scope == null) {
  4236                 log.warning(LintCategory.SERIAL,
  4237                         tree.pos(), "missing.SVUID", c);
  4238                 return;
  4241             // check that it is static final
  4242             VarSymbol svuid = (VarSymbol)e.sym;
  4243             if ((svuid.flags() & (STATIC | FINAL)) !=
  4244                 (STATIC | FINAL))
  4245                 log.warning(LintCategory.SERIAL,
  4246                         TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
  4248             // check that it is long
  4249             else if (!svuid.type.hasTag(LONG))
  4250                 log.warning(LintCategory.SERIAL,
  4251                         TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
  4253             // check constant
  4254             else if (svuid.getConstValue() == null)
  4255                 log.warning(LintCategory.SERIAL,
  4256                         TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
  4259     private Type capture(Type type) {
  4260         //do not capture free types
  4261         return resultInfo.checkContext.inferenceContext().free(type) ?
  4262                 type : types.capture(type);
  4265     private void validateTypeAnnotations(JCTree tree) {
  4266         tree.accept(typeAnnotationsValidator);
  4268     //where
  4269     private final JCTree.Visitor typeAnnotationsValidator =
  4270         new TreeScanner() {
  4271         public void visitAnnotation(JCAnnotation tree) {
  4272             if (tree.hasTag(TYPE_ANNOTATION)) {
  4273                 // TODO: It seems to WMD as if the annotation in
  4274                 // parameters, in particular also the recvparam, are never
  4275                 // of type JCTypeAnnotation and therefore never checked!
  4276                 // Luckily this check doesn't really do anything that isn't
  4277                 // also done elsewhere.
  4278                 chk.validateTypeAnnotation(tree, false);
  4280             super.visitAnnotation(tree);
  4282         public void visitTypeParameter(JCTypeParameter tree) {
  4283             chk.validateTypeAnnotations(tree.annotations, true);
  4284             scan(tree.bounds);
  4285             // Don't call super.
  4286             // This is needed because above we call validateTypeAnnotation with
  4287             // false, which would forbid annotations on type parameters.
  4288             // super.visitTypeParameter(tree);
  4290         public void visitMethodDef(JCMethodDecl tree) {
  4291             // Static methods cannot have receiver type annotations.
  4292             // In test case FailOver15.java, the nested method getString has
  4293             // a null sym, because an unknown class is instantiated.
  4294             // I would say it's safe to skip.
  4295             if (tree.sym != null && (tree.sym.flags() & Flags.STATIC) != 0) {
  4296                 if (tree.recvparam != null) {
  4297                     // TODO: better error message. Is the pos good?
  4298                     log.error(tree.recvparam.pos(), "annotation.type.not.applicable");
  4301             if (tree.restype != null && tree.restype.type != null) {
  4302                 validateAnnotatedType(tree.restype, tree.restype.type);
  4304             super.visitMethodDef(tree);
  4306         public void visitVarDef(final JCVariableDecl tree) {
  4307             if (tree.sym != null && tree.sym.type != null)
  4308                 validateAnnotatedType(tree, tree.sym.type);
  4309             super.visitVarDef(tree);
  4311         public void visitTypeCast(JCTypeCast tree) {
  4312             if (tree.clazz != null && tree.clazz.type != null)
  4313                 validateAnnotatedType(tree.clazz, tree.clazz.type);
  4314             super.visitTypeCast(tree);
  4316         public void visitTypeTest(JCInstanceOf tree) {
  4317             if (tree.clazz != null && tree.clazz.type != null)
  4318                 validateAnnotatedType(tree.clazz, tree.clazz.type);
  4319             super.visitTypeTest(tree);
  4321         // TODO: what else do we need?
  4322         // public void visitNewClass(JCNewClass tree) {
  4323         // public void visitNewArray(JCNewArray tree) {
  4325         /* I would want to model this after
  4326          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
  4327          * and override visitSelect and visitTypeApply.
  4328          * However, we only set the annotated type in the top-level type
  4329          * of the symbol.
  4330          * Therefore, we need to override each individual location where a type
  4331          * can occur.
  4332          */
  4333         private void validateAnnotatedType(final JCTree errtree, final Type type) {
  4334             if (type.getEnclosingType() != null &&
  4335                     type != type.getEnclosingType()) {
  4336                 validateEnclosingAnnotatedType(errtree, type.getEnclosingType());
  4338             for (Type targ : type.getTypeArguments()) {
  4339                 validateAnnotatedType(errtree, targ);
  4342         private void validateEnclosingAnnotatedType(final JCTree errtree, final Type type) {
  4343             validateAnnotatedType(errtree, type);
  4344             if (type.tsym != null &&
  4345                     type.tsym.isStatic() &&
  4346                     type.getAnnotationMirrors().nonEmpty()) {
  4347                     // Enclosing static classes cannot have type annotations.
  4348                 log.error(errtree.pos(), "cant.annotate.static.class");
  4351     };
  4353     // <editor-fold desc="post-attribution visitor">
  4355     /**
  4356      * Handle missing types/symbols in an AST. This routine is useful when
  4357      * the compiler has encountered some errors (which might have ended up
  4358      * terminating attribution abruptly); if the compiler is used in fail-over
  4359      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
  4360      * prevents NPE to be progagated during subsequent compilation steps.
  4361      */
  4362     public void postAttr(JCTree tree) {
  4363         new PostAttrAnalyzer().scan(tree);
  4366     class PostAttrAnalyzer extends TreeScanner {
  4368         private void initTypeIfNeeded(JCTree that) {
  4369             if (that.type == null) {
  4370                 that.type = syms.unknownType;
  4374         @Override
  4375         public void scan(JCTree tree) {
  4376             if (tree == null) return;
  4377             if (tree instanceof JCExpression) {
  4378                 initTypeIfNeeded(tree);
  4380             super.scan(tree);
  4383         @Override
  4384         public void visitIdent(JCIdent that) {
  4385             if (that.sym == null) {
  4386                 that.sym = syms.unknownSymbol;
  4390         @Override
  4391         public void visitSelect(JCFieldAccess that) {
  4392             if (that.sym == null) {
  4393                 that.sym = syms.unknownSymbol;
  4395             super.visitSelect(that);
  4398         @Override
  4399         public void visitClassDef(JCClassDecl that) {
  4400             initTypeIfNeeded(that);
  4401             if (that.sym == null) {
  4402                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
  4404             super.visitClassDef(that);
  4407         @Override
  4408         public void visitMethodDef(JCMethodDecl that) {
  4409             initTypeIfNeeded(that);
  4410             if (that.sym == null) {
  4411                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
  4413             super.visitMethodDef(that);
  4416         @Override
  4417         public void visitVarDef(JCVariableDecl that) {
  4418             initTypeIfNeeded(that);
  4419             if (that.sym == null) {
  4420                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
  4421                 that.sym.adr = 0;
  4423             super.visitVarDef(that);
  4426         @Override
  4427         public void visitNewClass(JCNewClass that) {
  4428             if (that.constructor == null) {
  4429                 that.constructor = new MethodSymbol(0, names.init, syms.unknownType, syms.noSymbol);
  4431             if (that.constructorType == null) {
  4432                 that.constructorType = syms.unknownType;
  4434             super.visitNewClass(that);
  4437         @Override
  4438         public void visitAssignop(JCAssignOp that) {
  4439             if (that.operator == null)
  4440                 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
  4441             super.visitAssignop(that);
  4444         @Override
  4445         public void visitBinary(JCBinary that) {
  4446             if (that.operator == null)
  4447                 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
  4448             super.visitBinary(that);
  4451         @Override
  4452         public void visitUnary(JCUnary that) {
  4453             if (that.operator == null)
  4454                 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
  4455             super.visitUnary(that);
  4458         @Override
  4459         public void visitLambda(JCLambda that) {
  4460             super.visitLambda(that);
  4461             if (that.descriptorType == null) {
  4462                 that.descriptorType = syms.unknownType;
  4464             if (that.targets == null) {
  4465                 that.targets = List.nil();
  4469         @Override
  4470         public void visitReference(JCMemberReference that) {
  4471             super.visitReference(that);
  4472             if (that.sym == null) {
  4473                 that.sym = new MethodSymbol(0, names.empty, syms.unknownType, syms.noSymbol);
  4475             if (that.descriptorType == null) {
  4476                 that.descriptorType = syms.unknownType;
  4478             if (that.targets == null) {
  4479                 that.targets = List.nil();
  4483     // </editor-fold>

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