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

Mon, 12 Aug 2013 17:28:31 +0100

author
mcimadamore
date
Mon, 12 Aug 2013 17:28:31 +0100
changeset 1946
af80273f630a
parent 1924
cd9e8cea1b3c
child 1955
ec77c7b46c37
permissions
-rw-r--r--

8021567: Javac doesn't report \"java: reference to method is ambiguous\" any more
Summary: Javac incorrectly forgets about constant folding results within lambdas
Reviewed-by: jjg, vromero

     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         allowTypeAnnos = source.allowTypeAnnotations();
   138         allowLambda = source.allowLambda();
   139         allowDefaultMethods = source.allowDefaultMethods();
   140         sourceName = source.name;
   141         relax = (options.isSet("-retrofit") ||
   142                  options.isSet("-relax"));
   143         findDiamonds = options.get("findDiamond") != null &&
   144                  source.allowDiamond();
   145         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
   146         identifyLambdaCandidate = options.getBoolean("identifyLambdaCandidate", false);
   148         statInfo = new ResultInfo(NIL, Type.noType);
   149         varInfo = new ResultInfo(VAR, Type.noType);
   150         unknownExprInfo = new ResultInfo(VAL, Type.noType);
   151         unknownAnyPolyInfo = new ResultInfo(VAL, Infer.anyPoly);
   152         unknownTypeInfo = new ResultInfo(TYP, Type.noType);
   153         unknownTypeExprInfo = new ResultInfo(Kinds.TYP | Kinds.VAL, Type.noType);
   154         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
   155     }
   157     /** Switch: relax some constraints for retrofit mode.
   158      */
   159     boolean relax;
   161     /** Switch: support target-typing inference
   162      */
   163     boolean allowPoly;
   165     /** Switch: support type annotations.
   166      */
   167     boolean allowTypeAnnos;
   169     /** Switch: support generics?
   170      */
   171     boolean allowGenerics;
   173     /** Switch: allow variable-arity methods.
   174      */
   175     boolean allowVarargs;
   177     /** Switch: support enums?
   178      */
   179     boolean allowEnums;
   181     /** Switch: support boxing and unboxing?
   182      */
   183     boolean allowBoxing;
   185     /** Switch: support covariant result types?
   186      */
   187     boolean allowCovariantReturns;
   189     /** Switch: support lambda expressions ?
   190      */
   191     boolean allowLambda;
   193     /** Switch: support default methods ?
   194      */
   195     boolean allowDefaultMethods;
   197     /** Switch: allow references to surrounding object from anonymous
   198      * objects during constructor call?
   199      */
   200     boolean allowAnonOuterThis;
   202     /** Switch: generates a warning if diamond can be safely applied
   203      *  to a given new expression
   204      */
   205     boolean findDiamonds;
   207     /**
   208      * Internally enables/disables diamond finder feature
   209      */
   210     static final boolean allowDiamondFinder = true;
   212     /**
   213      * Switch: warn about use of variable before declaration?
   214      * RFE: 6425594
   215      */
   216     boolean useBeforeDeclarationWarning;
   218     /**
   219      * Switch: generate warnings whenever an anonymous inner class that is convertible
   220      * to a lambda expression is found
   221      */
   222     boolean identifyLambdaCandidate;
   224     /**
   225      * Switch: allow strings in switch?
   226      */
   227     boolean allowStringsInSwitch;
   229     /**
   230      * Switch: name of source level; used for error reporting.
   231      */
   232     String sourceName;
   234     /** Check kind and type of given tree against protokind and prototype.
   235      *  If check succeeds, store type in tree and return it.
   236      *  If check fails, store errType in tree and return it.
   237      *  No checks are performed if the prototype is a method type.
   238      *  It is not necessary in this case since we know that kind and type
   239      *  are correct.
   240      *
   241      *  @param tree     The tree whose kind and type is checked
   242      *  @param ownkind  The computed kind of the tree
   243      *  @param resultInfo  The expected result of the tree
   244      */
   245     Type check(final JCTree tree, final Type found, final int ownkind, final ResultInfo resultInfo) {
   246         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
   247         Type owntype = found;
   248         if (!owntype.hasTag(ERROR) && !resultInfo.pt.hasTag(METHOD) && !resultInfo.pt.hasTag(FORALL)) {
   249             if (allowPoly && inferenceContext.free(found)) {
   250                 inferenceContext.addFreeTypeListener(List.of(found, resultInfo.pt), new FreeTypeListener() {
   251                     @Override
   252                     public void typesInferred(InferenceContext inferenceContext) {
   253                         ResultInfo pendingResult =
   254                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
   255                         check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
   256                     }
   257                 });
   258                 return tree.type = resultInfo.pt;
   259             } else {
   260                 if ((ownkind & ~resultInfo.pkind) == 0) {
   261                     owntype = resultInfo.check(tree, owntype);
   262                 } else {
   263                     log.error(tree.pos(), "unexpected.type",
   264                             kindNames(resultInfo.pkind),
   265                             kindName(ownkind));
   266                     owntype = types.createErrorType(owntype);
   267                 }
   268             }
   269         }
   270         tree.type = owntype;
   271         return owntype;
   272     }
   274     /** Is given blank final variable assignable, i.e. in a scope where it
   275      *  may be assigned to even though it is final?
   276      *  @param v      The blank final variable.
   277      *  @param env    The current environment.
   278      */
   279     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
   280         Symbol owner = owner(env);
   281            // owner refers to the innermost variable, method or
   282            // initializer block declaration at this point.
   283         return
   284             v.owner == owner
   285             ||
   286             ((owner.name == names.init ||    // i.e. we are in a constructor
   287               owner.kind == VAR ||           // i.e. we are in a variable initializer
   288               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
   289              &&
   290              v.owner == owner.owner
   291              &&
   292              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
   293     }
   295     /**
   296      * Return the innermost enclosing owner symbol in a given attribution context
   297      */
   298     Symbol owner(Env<AttrContext> env) {
   299         while (true) {
   300             switch (env.tree.getTag()) {
   301                 case VARDEF:
   302                     //a field can be owner
   303                     VarSymbol vsym = ((JCVariableDecl)env.tree).sym;
   304                     if (vsym.owner.kind == TYP) {
   305                         return vsym;
   306                     }
   307                     break;
   308                 case METHODDEF:
   309                     //method def is always an owner
   310                     return ((JCMethodDecl)env.tree).sym;
   311                 case CLASSDEF:
   312                     //class def is always an owner
   313                     return ((JCClassDecl)env.tree).sym;
   314                 case LAMBDA:
   315                     //a lambda is an owner - return a fresh synthetic method symbol
   316                     return new MethodSymbol(0, names.empty, null, syms.methodClass);
   317                 case BLOCK:
   318                     //static/instance init blocks are owner
   319                     Symbol blockSym = env.info.scope.owner;
   320                     if ((blockSym.flags() & BLOCK) != 0) {
   321                         return blockSym;
   322                     }
   323                     break;
   324                 case TOPLEVEL:
   325                     //toplevel is always an owner (for pkge decls)
   326                     return env.info.scope.owner;
   327             }
   328             Assert.checkNonNull(env.next);
   329             env = env.next;
   330         }
   331     }
   333     /** Check that variable can be assigned to.
   334      *  @param pos    The current source code position.
   335      *  @param v      The assigned varaible
   336      *  @param base   If the variable is referred to in a Select, the part
   337      *                to the left of the `.', null otherwise.
   338      *  @param env    The current environment.
   339      */
   340     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
   341         if ((v.flags() & FINAL) != 0 &&
   342             ((v.flags() & HASINIT) != 0
   343              ||
   344              !((base == null ||
   345                (base.hasTag(IDENT) && TreeInfo.name(base) == names._this)) &&
   346                isAssignableAsBlankFinal(v, env)))) {
   347             if (v.isResourceVariable()) { //TWR resource
   348                 log.error(pos, "try.resource.may.not.be.assigned", v);
   349             } else {
   350                 log.error(pos, "cant.assign.val.to.final.var", v);
   351             }
   352         }
   353     }
   355     /** Does tree represent a static reference to an identifier?
   356      *  It is assumed that tree is either a SELECT or an IDENT.
   357      *  We have to weed out selects from non-type names here.
   358      *  @param tree    The candidate tree.
   359      */
   360     boolean isStaticReference(JCTree tree) {
   361         if (tree.hasTag(SELECT)) {
   362             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
   363             if (lsym == null || lsym.kind != TYP) {
   364                 return false;
   365             }
   366         }
   367         return true;
   368     }
   370     /** Is this symbol a type?
   371      */
   372     static boolean isType(Symbol sym) {
   373         return sym != null && sym.kind == TYP;
   374     }
   376     /** The current `this' symbol.
   377      *  @param env    The current environment.
   378      */
   379     Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
   380         return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
   381     }
   383     /** Attribute a parsed identifier.
   384      * @param tree Parsed identifier name
   385      * @param topLevel The toplevel to use
   386      */
   387     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
   388         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
   389         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
   390                                            syms.errSymbol.name,
   391                                            null, null, null, null);
   392         localEnv.enclClass.sym = syms.errSymbol;
   393         return tree.accept(identAttributer, localEnv);
   394     }
   395     // where
   396         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
   397         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
   398             @Override
   399             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
   400                 Symbol site = visit(node.getExpression(), env);
   401                 if (site.kind == ERR)
   402                     return site;
   403                 Name name = (Name)node.getIdentifier();
   404                 if (site.kind == PCK) {
   405                     env.toplevel.packge = (PackageSymbol)site;
   406                     return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
   407                 } else {
   408                     env.enclClass.sym = (ClassSymbol)site;
   409                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
   410                 }
   411             }
   413             @Override
   414             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
   415                 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
   416             }
   417         }
   419     public Type coerce(Type etype, Type ttype) {
   420         return cfolder.coerce(etype, ttype);
   421     }
   423     public Type attribType(JCTree node, TypeSymbol sym) {
   424         Env<AttrContext> env = enter.typeEnvs.get(sym);
   425         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
   426         return attribTree(node, localEnv, unknownTypeInfo);
   427     }
   429     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
   430         // Attribute qualifying package or class.
   431         JCFieldAccess s = (JCFieldAccess)tree.qualid;
   432         return attribTree(s.selected,
   433                        env,
   434                        new ResultInfo(tree.staticImport ? TYP : (TYP | PCK),
   435                        Type.noType));
   436     }
   438     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
   439         breakTree = tree;
   440         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
   441         try {
   442             attribExpr(expr, env);
   443         } catch (BreakAttr b) {
   444             return b.env;
   445         } catch (AssertionError ae) {
   446             if (ae.getCause() instanceof BreakAttr) {
   447                 return ((BreakAttr)(ae.getCause())).env;
   448             } else {
   449                 throw ae;
   450             }
   451         } finally {
   452             breakTree = null;
   453             log.useSource(prev);
   454         }
   455         return env;
   456     }
   458     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
   459         breakTree = tree;
   460         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
   461         try {
   462             attribStat(stmt, env);
   463         } catch (BreakAttr b) {
   464             return b.env;
   465         } catch (AssertionError ae) {
   466             if (ae.getCause() instanceof BreakAttr) {
   467                 return ((BreakAttr)(ae.getCause())).env;
   468             } else {
   469                 throw ae;
   470             }
   471         } finally {
   472             breakTree = null;
   473             log.useSource(prev);
   474         }
   475         return env;
   476     }
   478     private JCTree breakTree = null;
   480     private static class BreakAttr extends RuntimeException {
   481         static final long serialVersionUID = -6924771130405446405L;
   482         private Env<AttrContext> env;
   483         private BreakAttr(Env<AttrContext> env) {
   484             this.env = env;
   485         }
   486     }
   488     class ResultInfo {
   489         final int pkind;
   490         final Type pt;
   491         final CheckContext checkContext;
   493         ResultInfo(int pkind, Type pt) {
   494             this(pkind, pt, chk.basicHandler);
   495         }
   497         protected ResultInfo(int pkind, Type pt, CheckContext checkContext) {
   498             this.pkind = pkind;
   499             this.pt = pt;
   500             this.checkContext = checkContext;
   501         }
   503         protected Type check(final DiagnosticPosition pos, final Type found) {
   504             return chk.checkType(pos, found, pt, checkContext);
   505         }
   507         protected ResultInfo dup(Type newPt) {
   508             return new ResultInfo(pkind, newPt, checkContext);
   509         }
   511         protected ResultInfo dup(CheckContext newContext) {
   512             return new ResultInfo(pkind, pt, newContext);
   513         }
   514     }
   516     class RecoveryInfo extends ResultInfo {
   518         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
   519             super(Kinds.VAL, Type.recoveryType, new Check.NestedCheckContext(chk.basicHandler) {
   520                 @Override
   521                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
   522                     return deferredAttrContext;
   523                 }
   524                 @Override
   525                 public boolean compatible(Type found, Type req, Warner warn) {
   526                     return true;
   527                 }
   528                 @Override
   529                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
   530                     chk.basicHandler.report(pos, details);
   531                 }
   532             });
   533         }
   534     }
   536     final ResultInfo statInfo;
   537     final ResultInfo varInfo;
   538     final ResultInfo unknownAnyPolyInfo;
   539     final ResultInfo unknownExprInfo;
   540     final ResultInfo unknownTypeInfo;
   541     final ResultInfo unknownTypeExprInfo;
   542     final ResultInfo recoveryInfo;
   544     Type pt() {
   545         return resultInfo.pt;
   546     }
   548     int pkind() {
   549         return resultInfo.pkind;
   550     }
   552 /* ************************************************************************
   553  * Visitor methods
   554  *************************************************************************/
   556     /** Visitor argument: the current environment.
   557      */
   558     Env<AttrContext> env;
   560     /** Visitor argument: the currently expected attribution result.
   561      */
   562     ResultInfo resultInfo;
   564     /** Visitor result: the computed type.
   565      */
   566     Type result;
   568     /** Visitor method: attribute a tree, catching any completion failure
   569      *  exceptions. Return the tree's type.
   570      *
   571      *  @param tree    The tree to be visited.
   572      *  @param env     The environment visitor argument.
   573      *  @param resultInfo   The result info visitor argument.
   574      */
   575     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
   576         Env<AttrContext> prevEnv = this.env;
   577         ResultInfo prevResult = this.resultInfo;
   578         try {
   579             this.env = env;
   580             this.resultInfo = resultInfo;
   581             tree.accept(this);
   582             if (tree == breakTree &&
   583                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
   584                 throw new BreakAttr(copyEnv(env));
   585             }
   586             return result;
   587         } catch (CompletionFailure ex) {
   588             tree.type = syms.errType;
   589             return chk.completionError(tree.pos(), ex);
   590         } finally {
   591             this.env = prevEnv;
   592             this.resultInfo = prevResult;
   593         }
   594     }
   596     Env<AttrContext> copyEnv(Env<AttrContext> env) {
   597         Env<AttrContext> newEnv =
   598                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
   599         if (newEnv.outer != null) {
   600             newEnv.outer = copyEnv(newEnv.outer);
   601         }
   602         return newEnv;
   603     }
   605     Scope copyScope(Scope sc) {
   606         Scope newScope = new Scope(sc.owner);
   607         List<Symbol> elemsList = List.nil();
   608         while (sc != null) {
   609             for (Scope.Entry e = sc.elems ; e != null ; e = e.sibling) {
   610                 elemsList = elemsList.prepend(e.sym);
   611             }
   612             sc = sc.next;
   613         }
   614         for (Symbol s : elemsList) {
   615             newScope.enter(s);
   616         }
   617         return newScope;
   618     }
   620     /** Derived visitor method: attribute an expression tree.
   621      */
   622     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
   623         return attribTree(tree, env, new ResultInfo(VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
   624     }
   626     /** Derived visitor method: attribute an expression tree with
   627      *  no constraints on the computed type.
   628      */
   629     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
   630         return attribTree(tree, env, unknownExprInfo);
   631     }
   633     /** Derived visitor method: attribute a type tree.
   634      */
   635     public Type attribType(JCTree tree, Env<AttrContext> env) {
   636         Type result = attribType(tree, env, Type.noType);
   637         return result;
   638     }
   640     /** Derived visitor method: attribute a type tree.
   641      */
   642     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
   643         Type result = attribTree(tree, env, new ResultInfo(TYP, pt));
   644         return result;
   645     }
   647     /** Derived visitor method: attribute a statement or definition tree.
   648      */
   649     public Type attribStat(JCTree tree, Env<AttrContext> env) {
   650         return attribTree(tree, env, statInfo);
   651     }
   653     /** Attribute a list of expressions, returning a list of types.
   654      */
   655     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
   656         ListBuffer<Type> ts = new ListBuffer<Type>();
   657         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
   658             ts.append(attribExpr(l.head, env, pt));
   659         return ts.toList();
   660     }
   662     /** Attribute a list of statements, returning nothing.
   663      */
   664     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
   665         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
   666             attribStat(l.head, env);
   667     }
   669     /** Attribute the arguments in a method call, returning the method kind.
   670      */
   671     int attribArgs(List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
   672         int kind = VAL;
   673         for (JCExpression arg : trees) {
   674             Type argtype;
   675             if (allowPoly && deferredAttr.isDeferred(env, arg)) {
   676                 argtype = deferredAttr.new DeferredType(arg, env);
   677                 kind |= POLY;
   678             } else {
   679                 argtype = chk.checkNonVoid(arg, attribTree(arg, env, unknownAnyPolyInfo));
   680             }
   681             argtypes.append(argtype);
   682         }
   683         return kind;
   684     }
   686     /** Attribute a type argument list, returning a list of types.
   687      *  Caller is responsible for calling checkRefTypes.
   688      */
   689     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
   690         ListBuffer<Type> argtypes = new ListBuffer<Type>();
   691         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
   692             argtypes.append(attribType(l.head, env));
   693         return argtypes.toList();
   694     }
   696     /** Attribute a type argument list, returning a list of types.
   697      *  Check that all the types are references.
   698      */
   699     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
   700         List<Type> types = attribAnyTypes(trees, env);
   701         return chk.checkRefTypes(trees, types);
   702     }
   704     /**
   705      * Attribute type variables (of generic classes or methods).
   706      * Compound types are attributed later in attribBounds.
   707      * @param typarams the type variables to enter
   708      * @param env      the current environment
   709      */
   710     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
   711         for (JCTypeParameter tvar : typarams) {
   712             TypeVar a = (TypeVar)tvar.type;
   713             a.tsym.flags_field |= UNATTRIBUTED;
   714             a.bound = Type.noType;
   715             if (!tvar.bounds.isEmpty()) {
   716                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
   717                 for (JCExpression bound : tvar.bounds.tail)
   718                     bounds = bounds.prepend(attribType(bound, env));
   719                 types.setBounds(a, bounds.reverse());
   720             } else {
   721                 // if no bounds are given, assume a single bound of
   722                 // java.lang.Object.
   723                 types.setBounds(a, List.of(syms.objectType));
   724             }
   725             a.tsym.flags_field &= ~UNATTRIBUTED;
   726         }
   727         for (JCTypeParameter tvar : typarams) {
   728             chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
   729         }
   730     }
   732     /**
   733      * Attribute the type references in a list of annotations.
   734      */
   735     void attribAnnotationTypes(List<JCAnnotation> annotations,
   736                                Env<AttrContext> env) {
   737         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
   738             JCAnnotation a = al.head;
   739             attribType(a.annotationType, env);
   740         }
   741     }
   743     /**
   744      * Attribute a "lazy constant value".
   745      *  @param env         The env for the const value
   746      *  @param initializer The initializer for the const value
   747      *  @param type        The expected type, or null
   748      *  @see VarSymbol#setLazyConstValue
   749      */
   750     public Object attribLazyConstantValue(Env<AttrContext> env,
   751                                       JCTree.JCExpression initializer,
   752                                       Type type) {
   754         /*  When this env was created, it didn't have the correct lint nor had
   755          *  annotations has been processed.
   756          *  But now at this phase we have already processed annotations and the
   757          *  correct lint must have been set in chk, so we should use that one to
   758          *  attribute the initializer.
   759          */
   760         Lint prevLint = env.info.lint;
   761         env.info.lint = chk.getLint();
   763         JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
   765         try {
   766             // Use null as symbol to not attach the type annotation to any symbol.
   767             // The initializer will later also be visited and then we'll attach
   768             // to the symbol.
   769             // This prevents having multiple type annotations, just because of
   770             // lazy constant value evaluation.
   771             memberEnter.typeAnnotate(initializer, env, null);
   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             }
   779         } finally {
   780             env.info.lint = prevLint;
   781             log.useSource(prevSource);
   782         }
   783     }
   785     /** Attribute type reference in an `extends' or `implements' clause.
   786      *  Supertypes of anonymous inner classes are usually already attributed.
   787      *
   788      *  @param tree              The tree making up the type reference.
   789      *  @param env               The environment current at the reference.
   790      *  @param classExpected     true if only a class is expected here.
   791      *  @param interfaceExpected true if only an interface is expected here.
   792      */
   793     Type attribBase(JCTree tree,
   794                     Env<AttrContext> env,
   795                     boolean classExpected,
   796                     boolean interfaceExpected,
   797                     boolean checkExtensible) {
   798         Type t = tree.type != null ?
   799             tree.type :
   800             attribType(tree, env);
   801         return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
   802     }
   803     Type checkBase(Type t,
   804                    JCTree tree,
   805                    Env<AttrContext> env,
   806                    boolean classExpected,
   807                    boolean interfaceExpected,
   808                    boolean checkExtensible) {
   809         if (t.isErroneous())
   810             return t;
   811         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
   812             // check that type variable is already visible
   813             if (t.getUpperBound() == null) {
   814                 log.error(tree.pos(), "illegal.forward.ref");
   815                 return types.createErrorType(t);
   816             }
   817         } else {
   818             t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
   819         }
   820         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
   821             log.error(tree.pos(), "intf.expected.here");
   822             // return errType is necessary since otherwise there might
   823             // be undetected cycles which cause attribution to loop
   824             return types.createErrorType(t);
   825         } else if (checkExtensible &&
   826                    classExpected &&
   827                    (t.tsym.flags() & INTERFACE) != 0) {
   828                 log.error(tree.pos(), "no.intf.expected.here");
   829             return types.createErrorType(t);
   830         }
   831         if (checkExtensible &&
   832             ((t.tsym.flags() & FINAL) != 0)) {
   833             log.error(tree.pos(),
   834                       "cant.inherit.from.final", t.tsym);
   835         }
   836         chk.checkNonCyclic(tree.pos(), t);
   837         return t;
   838     }
   840     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
   841         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
   842         id.type = env.info.scope.owner.type;
   843         id.sym = env.info.scope.owner;
   844         return id.type;
   845     }
   847     public void visitClassDef(JCClassDecl tree) {
   848         // Local classes have not been entered yet, so we need to do it now:
   849         if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
   850             enter.classEnter(tree, env);
   852         ClassSymbol c = tree.sym;
   853         if (c == null) {
   854             // exit in case something drastic went wrong during enter.
   855             result = null;
   856         } else {
   857             // make sure class has been completed:
   858             c.complete();
   860             // If this class appears as an anonymous class
   861             // in a superclass constructor call where
   862             // no explicit outer instance is given,
   863             // disable implicit outer instance from being passed.
   864             // (This would be an illegal access to "this before super").
   865             if (env.info.isSelfCall &&
   866                 env.tree.hasTag(NEWCLASS) &&
   867                 ((JCNewClass) env.tree).encl == null)
   868             {
   869                 c.flags_field |= NOOUTERTHIS;
   870             }
   871             attribClass(tree.pos(), c);
   872             result = tree.type = c.type;
   873         }
   874     }
   876     public void visitMethodDef(JCMethodDecl tree) {
   877         MethodSymbol m = tree.sym;
   878         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
   880         Lint lint = env.info.lint.augment(m);
   881         Lint prevLint = chk.setLint(lint);
   882         MethodSymbol prevMethod = chk.setMethod(m);
   883         try {
   884             deferredLintHandler.flush(tree.pos());
   885             chk.checkDeprecatedAnnotation(tree.pos(), m);
   888             // Create a new environment with local scope
   889             // for attributing the method.
   890             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
   891             localEnv.info.lint = lint;
   893             attribStats(tree.typarams, localEnv);
   895             // If we override any other methods, check that we do so properly.
   896             // JLS ???
   897             if (m.isStatic()) {
   898                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
   899             } else {
   900                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
   901             }
   902             chk.checkOverride(tree, m);
   904             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
   905                 log.error(tree, "default.overrides.object.member", m.name, Kinds.kindName(m.location()), m.location());
   906             }
   908             // Enter all type parameters into the local method scope.
   909             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
   910                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
   912             ClassSymbol owner = env.enclClass.sym;
   913             if ((owner.flags() & ANNOTATION) != 0 &&
   914                 tree.params.nonEmpty())
   915                 log.error(tree.params.head.pos(),
   916                           "intf.annotation.members.cant.have.params");
   918             // Attribute all value parameters.
   919             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
   920                 attribStat(l.head, localEnv);
   921             }
   923             chk.checkVarargsMethodDecl(localEnv, tree);
   925             // Check that type parameters are well-formed.
   926             chk.validate(tree.typarams, localEnv);
   928             // Check that result type is well-formed.
   929             chk.validate(tree.restype, localEnv);
   931             // Check that receiver type is well-formed.
   932             if (tree.recvparam != null) {
   933                 // Use a new environment to check the receiver parameter.
   934                 // Otherwise I get "might not have been initialized" errors.
   935                 // Is there a better way?
   936                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
   937                 attribType(tree.recvparam, newEnv);
   938                 chk.validate(tree.recvparam, newEnv);
   939             }
   941             // annotation method checks
   942             if ((owner.flags() & ANNOTATION) != 0) {
   943                 // annotation method cannot have throws clause
   944                 if (tree.thrown.nonEmpty()) {
   945                     log.error(tree.thrown.head.pos(),
   946                             "throws.not.allowed.in.intf.annotation");
   947                 }
   948                 // annotation method cannot declare type-parameters
   949                 if (tree.typarams.nonEmpty()) {
   950                     log.error(tree.typarams.head.pos(),
   951                             "intf.annotation.members.cant.have.type.params");
   952                 }
   953                 // validate annotation method's return type (could be an annotation type)
   954                 chk.validateAnnotationType(tree.restype);
   955                 // ensure that annotation method does not clash with members of Object/Annotation
   956                 chk.validateAnnotationMethod(tree.pos(), m);
   958                 if (tree.defaultValue != null) {
   959                     // if default value is an annotation, check it is a well-formed
   960                     // annotation value (e.g. no duplicate values, no missing values, etc.)
   961                     chk.validateAnnotationTree(tree.defaultValue);
   962                 }
   963             }
   965             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
   966                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
   968             if (tree.body == null) {
   969                 // Empty bodies are only allowed for
   970                 // abstract, native, or interface methods, or for methods
   971                 // in a retrofit signature class.
   972                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0 &&
   973                     !relax)
   974                     log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
   975                 if (tree.defaultValue != null) {
   976                     if ((owner.flags() & ANNOTATION) == 0)
   977                         log.error(tree.pos(),
   978                                   "default.allowed.in.intf.annotation.member");
   979                 }
   980             } else if ((tree.sym.flags() & ABSTRACT) != 0 && !isDefaultMethod) {
   981                 if ((owner.flags() & INTERFACE) != 0) {
   982                     log.error(tree.body.pos(), "intf.meth.cant.have.body");
   983                 } else {
   984                     log.error(tree.pos(), "abstract.meth.cant.have.body");
   985                 }
   986             } else if ((tree.mods.flags & NATIVE) != 0) {
   987                 log.error(tree.pos(), "native.meth.cant.have.body");
   988             } else {
   989                 // Add an implicit super() call unless an explicit call to
   990                 // super(...) or this(...) is given
   991                 // or we are compiling class java.lang.Object.
   992                 if (tree.name == names.init && owner.type != syms.objectType) {
   993                     JCBlock body = tree.body;
   994                     if (body.stats.isEmpty() ||
   995                         !TreeInfo.isSelfCall(body.stats.head)) {
   996                         body.stats = body.stats.
   997                             prepend(memberEnter.SuperCall(make.at(body.pos),
   998                                                           List.<Type>nil(),
   999                                                           List.<JCVariableDecl>nil(),
  1000                                                           false));
  1001                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
  1002                                (tree.mods.flags & GENERATEDCONSTR) == 0 &&
  1003                                TreeInfo.isSuperCall(body.stats.head)) {
  1004                         // enum constructors are not allowed to call super
  1005                         // directly, so make sure there aren't any super calls
  1006                         // in enum constructors, except in the compiler
  1007                         // generated one.
  1008                         log.error(tree.body.stats.head.pos(),
  1009                                   "call.to.super.not.allowed.in.enum.ctor",
  1010                                   env.enclClass.sym);
  1014                 // Attribute all type annotations in the body
  1015                 memberEnter.typeAnnotate(tree.body, localEnv, m);
  1016                 annotate.flush();
  1018                 // Attribute method body.
  1019                 attribStat(tree.body, localEnv);
  1022             localEnv.info.scope.leave();
  1023             result = tree.type = m.type;
  1024             chk.validateAnnotations(tree.mods.annotations, m);
  1026         finally {
  1027             chk.setLint(prevLint);
  1028             chk.setMethod(prevMethod);
  1032     public void visitVarDef(JCVariableDecl tree) {
  1033         // Local variables have not been entered yet, so we need to do it now:
  1034         if (env.info.scope.owner.kind == MTH) {
  1035             if (tree.sym != null) {
  1036                 // parameters have already been entered
  1037                 env.info.scope.enter(tree.sym);
  1038             } else {
  1039                 memberEnter.memberEnter(tree, env);
  1040                 annotate.flush();
  1042         } else {
  1043             if (tree.init != null) {
  1044                 // Field initializer expression need to be entered.
  1045                 memberEnter.typeAnnotate(tree.init, env, tree.sym);
  1046                 annotate.flush();
  1050         VarSymbol v = tree.sym;
  1051         Lint lint = env.info.lint.augment(v);
  1052         Lint prevLint = chk.setLint(lint);
  1054         // Check that the variable's declared type is well-formed.
  1055         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
  1056                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
  1057                 (tree.sym.flags() & PARAMETER) != 0;
  1058         chk.validate(tree.vartype, env, !isImplicitLambdaParameter);
  1059         deferredLintHandler.flush(tree.pos());
  1061         try {
  1062             chk.checkDeprecatedAnnotation(tree.pos(), v);
  1064             if (tree.init != null) {
  1065                 if ((v.flags_field & FINAL) != 0 &&
  1066                         !tree.init.hasTag(NEWCLASS) &&
  1067                         !tree.init.hasTag(LAMBDA) &&
  1068                         !tree.init.hasTag(REFERENCE)) {
  1069                     // In this case, `v' is final.  Ensure that it's initializer is
  1070                     // evaluated.
  1071                     v.getConstValue(); // ensure initializer is evaluated
  1072                 } else {
  1073                     // Attribute initializer in a new environment
  1074                     // with the declared variable as owner.
  1075                     // Check that initializer conforms to variable's declared type.
  1076                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
  1077                     initEnv.info.lint = lint;
  1078                     // In order to catch self-references, we set the variable's
  1079                     // declaration position to maximal possible value, effectively
  1080                     // marking the variable as undefined.
  1081                     initEnv.info.enclVar = v;
  1082                     attribExpr(tree.init, initEnv, v.type);
  1085             result = tree.type = v.type;
  1086             chk.validateAnnotations(tree.mods.annotations, v);
  1088         finally {
  1089             chk.setLint(prevLint);
  1093     public void visitSkip(JCSkip tree) {
  1094         result = null;
  1097     public void visitBlock(JCBlock tree) {
  1098         if (env.info.scope.owner.kind == TYP) {
  1099             // Block is a static or instance initializer;
  1100             // let the owner of the environment be a freshly
  1101             // created BLOCK-method.
  1102             Env<AttrContext> localEnv =
  1103                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
  1104             localEnv.info.scope.owner =
  1105                 new MethodSymbol(tree.flags | BLOCK |
  1106                     env.info.scope.owner.flags() & STRICTFP, names.empty, null,
  1107                     env.info.scope.owner);
  1108             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
  1110             // Attribute all type annotations in the block
  1111             memberEnter.typeAnnotate(tree, localEnv, localEnv.info.scope.owner);
  1112             annotate.flush();
  1115                 // Store init and clinit type annotations with the ClassSymbol
  1116                 // to allow output in Gen.normalizeDefs.
  1117                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
  1118                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
  1119                 if ((tree.flags & STATIC) != 0) {
  1120                     cs.appendClassInitTypeAttributes(tas);
  1121                 } else {
  1122                     cs.appendInitTypeAttributes(tas);
  1126             attribStats(tree.stats, localEnv);
  1127         } else {
  1128             // Create a new local environment with a local scope.
  1129             Env<AttrContext> localEnv =
  1130                 env.dup(tree, env.info.dup(env.info.scope.dup()));
  1131             try {
  1132                 attribStats(tree.stats, localEnv);
  1133             } finally {
  1134                 localEnv.info.scope.leave();
  1137         result = null;
  1140     public void visitDoLoop(JCDoWhileLoop tree) {
  1141         attribStat(tree.body, env.dup(tree));
  1142         attribExpr(tree.cond, env, syms.booleanType);
  1143         result = null;
  1146     public void visitWhileLoop(JCWhileLoop tree) {
  1147         attribExpr(tree.cond, env, syms.booleanType);
  1148         attribStat(tree.body, env.dup(tree));
  1149         result = null;
  1152     public void visitForLoop(JCForLoop tree) {
  1153         Env<AttrContext> loopEnv =
  1154             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
  1155         try {
  1156             attribStats(tree.init, loopEnv);
  1157             if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
  1158             loopEnv.tree = tree; // before, we were not in loop!
  1159             attribStats(tree.step, loopEnv);
  1160             attribStat(tree.body, loopEnv);
  1161             result = null;
  1163         finally {
  1164             loopEnv.info.scope.leave();
  1168     public void visitForeachLoop(JCEnhancedForLoop tree) {
  1169         Env<AttrContext> loopEnv =
  1170             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
  1171         try {
  1172             //the Formal Parameter of a for-each loop is not in the scope when
  1173             //attributing the for-each expression; we mimick this by attributing
  1174             //the for-each expression first (against original scope).
  1175             Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
  1176             attribStat(tree.var, loopEnv);
  1177             chk.checkNonVoid(tree.pos(), exprType);
  1178             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
  1179             if (elemtype == null) {
  1180                 // or perhaps expr implements Iterable<T>?
  1181                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
  1182                 if (base == null) {
  1183                     log.error(tree.expr.pos(),
  1184                             "foreach.not.applicable.to.type",
  1185                             exprType,
  1186                             diags.fragment("type.req.array.or.iterable"));
  1187                     elemtype = types.createErrorType(exprType);
  1188                 } else {
  1189                     List<Type> iterableParams = base.allparams();
  1190                     elemtype = iterableParams.isEmpty()
  1191                         ? syms.objectType
  1192                         : types.upperBound(iterableParams.head);
  1195             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
  1196             loopEnv.tree = tree; // before, we were not in loop!
  1197             attribStat(tree.body, loopEnv);
  1198             result = null;
  1200         finally {
  1201             loopEnv.info.scope.leave();
  1205     public void visitLabelled(JCLabeledStatement tree) {
  1206         // Check that label is not used in an enclosing statement
  1207         Env<AttrContext> env1 = env;
  1208         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
  1209             if (env1.tree.hasTag(LABELLED) &&
  1210                 ((JCLabeledStatement) env1.tree).label == tree.label) {
  1211                 log.error(tree.pos(), "label.already.in.use",
  1212                           tree.label);
  1213                 break;
  1215             env1 = env1.next;
  1218         attribStat(tree.body, env.dup(tree));
  1219         result = null;
  1222     public void visitSwitch(JCSwitch tree) {
  1223         Type seltype = attribExpr(tree.selector, env);
  1225         Env<AttrContext> switchEnv =
  1226             env.dup(tree, env.info.dup(env.info.scope.dup()));
  1228         try {
  1230             boolean enumSwitch =
  1231                 allowEnums &&
  1232                 (seltype.tsym.flags() & Flags.ENUM) != 0;
  1233             boolean stringSwitch = false;
  1234             if (types.isSameType(seltype, syms.stringType)) {
  1235                 if (allowStringsInSwitch) {
  1236                     stringSwitch = true;
  1237                 } else {
  1238                     log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName);
  1241             if (!enumSwitch && !stringSwitch)
  1242                 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
  1244             // Attribute all cases and
  1245             // check that there are no duplicate case labels or default clauses.
  1246             Set<Object> labels = new HashSet<Object>(); // The set of case labels.
  1247             boolean hasDefault = false;      // Is there a default label?
  1248             for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
  1249                 JCCase c = l.head;
  1250                 Env<AttrContext> caseEnv =
  1251                     switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
  1252                 try {
  1253                     if (c.pat != null) {
  1254                         if (enumSwitch) {
  1255                             Symbol sym = enumConstant(c.pat, seltype);
  1256                             if (sym == null) {
  1257                                 log.error(c.pat.pos(), "enum.label.must.be.unqualified.enum");
  1258                             } else if (!labels.add(sym)) {
  1259                                 log.error(c.pos(), "duplicate.case.label");
  1261                         } else {
  1262                             Type pattype = attribExpr(c.pat, switchEnv, seltype);
  1263                             if (!pattype.hasTag(ERROR)) {
  1264                                 if (pattype.constValue() == null) {
  1265                                     log.error(c.pat.pos(),
  1266                                               (stringSwitch ? "string.const.req" : "const.expr.req"));
  1267                                 } else if (labels.contains(pattype.constValue())) {
  1268                                     log.error(c.pos(), "duplicate.case.label");
  1269                                 } else {
  1270                                     labels.add(pattype.constValue());
  1274                     } else if (hasDefault) {
  1275                         log.error(c.pos(), "duplicate.default.label");
  1276                     } else {
  1277                         hasDefault = true;
  1279                     attribStats(c.stats, caseEnv);
  1280                 } finally {
  1281                     caseEnv.info.scope.leave();
  1282                     addVars(c.stats, switchEnv.info.scope);
  1286             result = null;
  1288         finally {
  1289             switchEnv.info.scope.leave();
  1292     // where
  1293         /** Add any variables defined in stats to the switch scope. */
  1294         private static void addVars(List<JCStatement> stats, Scope switchScope) {
  1295             for (;stats.nonEmpty(); stats = stats.tail) {
  1296                 JCTree stat = stats.head;
  1297                 if (stat.hasTag(VARDEF))
  1298                     switchScope.enter(((JCVariableDecl) stat).sym);
  1301     // where
  1302     /** Return the selected enumeration constant symbol, or null. */
  1303     private Symbol enumConstant(JCTree tree, Type enumType) {
  1304         if (!tree.hasTag(IDENT)) {
  1305             log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
  1306             return syms.errSymbol;
  1308         JCIdent ident = (JCIdent)tree;
  1309         Name name = ident.name;
  1310         for (Scope.Entry e = enumType.tsym.members().lookup(name);
  1311              e.scope != null; e = e.next()) {
  1312             if (e.sym.kind == VAR) {
  1313                 Symbol s = ident.sym = e.sym;
  1314                 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
  1315                 ident.type = s.type;
  1316                 return ((s.flags_field & Flags.ENUM) == 0)
  1317                     ? null : s;
  1320         return null;
  1323     public void visitSynchronized(JCSynchronized tree) {
  1324         chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
  1325         attribStat(tree.body, env);
  1326         result = null;
  1329     public void visitTry(JCTry tree) {
  1330         // Create a new local environment with a local
  1331         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
  1332         try {
  1333             boolean isTryWithResource = tree.resources.nonEmpty();
  1334             // Create a nested environment for attributing the try block if needed
  1335             Env<AttrContext> tryEnv = isTryWithResource ?
  1336                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
  1337                 localEnv;
  1338             try {
  1339                 // Attribute resource declarations
  1340                 for (JCTree resource : tree.resources) {
  1341                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
  1342                         @Override
  1343                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
  1344                             chk.basicHandler.report(pos, diags.fragment("try.not.applicable.to.type", details));
  1346                     };
  1347                     ResultInfo twrResult = new ResultInfo(VAL, syms.autoCloseableType, twrContext);
  1348                     if (resource.hasTag(VARDEF)) {
  1349                         attribStat(resource, tryEnv);
  1350                         twrResult.check(resource, resource.type);
  1352                         //check that resource type cannot throw InterruptedException
  1353                         checkAutoCloseable(resource.pos(), localEnv, resource.type);
  1355                         VarSymbol var = ((JCVariableDecl) resource).sym;
  1356                         var.setData(ElementKind.RESOURCE_VARIABLE);
  1357                     } else {
  1358                         attribTree(resource, tryEnv, twrResult);
  1361                 // Attribute body
  1362                 attribStat(tree.body, tryEnv);
  1363             } finally {
  1364                 if (isTryWithResource)
  1365                     tryEnv.info.scope.leave();
  1368             // Attribute catch clauses
  1369             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
  1370                 JCCatch c = l.head;
  1371                 Env<AttrContext> catchEnv =
  1372                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
  1373                 try {
  1374                     Type ctype = attribStat(c.param, catchEnv);
  1375                     if (TreeInfo.isMultiCatch(c)) {
  1376                         //multi-catch parameter is implicitly marked as final
  1377                         c.param.sym.flags_field |= FINAL | UNION;
  1379                     if (c.param.sym.kind == Kinds.VAR) {
  1380                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
  1382                     chk.checkType(c.param.vartype.pos(),
  1383                                   chk.checkClassType(c.param.vartype.pos(), ctype),
  1384                                   syms.throwableType);
  1385                     attribStat(c.body, catchEnv);
  1386                 } finally {
  1387                     catchEnv.info.scope.leave();
  1391             // Attribute finalizer
  1392             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
  1393             result = null;
  1395         finally {
  1396             localEnv.info.scope.leave();
  1400     void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
  1401         if (!resource.isErroneous() &&
  1402             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
  1403             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
  1404             Symbol close = syms.noSymbol;
  1405             Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log);
  1406             try {
  1407                 close = rs.resolveQualifiedMethod(pos,
  1408                         env,
  1409                         resource,
  1410                         names.close,
  1411                         List.<Type>nil(),
  1412                         List.<Type>nil());
  1414             finally {
  1415                 log.popDiagnosticHandler(discardHandler);
  1417             if (close.kind == MTH &&
  1418                     close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
  1419                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
  1420                     env.info.lint.isEnabled(LintCategory.TRY)) {
  1421                 log.warning(LintCategory.TRY, pos, "try.resource.throws.interrupted.exc", resource);
  1426     public void visitConditional(JCConditional tree) {
  1427         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
  1429         tree.polyKind = (!allowPoly ||
  1430                 pt().hasTag(NONE) && pt() != Type.recoveryType ||
  1431                 isBooleanOrNumeric(env, tree)) ?
  1432                 PolyKind.STANDALONE : PolyKind.POLY;
  1434         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
  1435             //cannot get here (i.e. it means we are returning from void method - which is already an error)
  1436             resultInfo.checkContext.report(tree, diags.fragment("conditional.target.cant.be.void"));
  1437             result = tree.type = types.createErrorType(resultInfo.pt);
  1438             return;
  1441         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
  1442                 unknownExprInfo :
  1443                 resultInfo.dup(new Check.NestedCheckContext(resultInfo.checkContext) {
  1444                     //this will use enclosing check context to check compatibility of
  1445                     //subexpression against target type; if we are in a method check context,
  1446                     //depending on whether boxing is allowed, we could have incompatibilities
  1447                     @Override
  1448                     public void report(DiagnosticPosition pos, JCDiagnostic details) {
  1449                         enclosingContext.report(pos, diags.fragment("incompatible.type.in.conditional", details));
  1451                 });
  1453         Type truetype = attribTree(tree.truepart, env, condInfo);
  1454         Type falsetype = attribTree(tree.falsepart, env, condInfo);
  1456         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(tree, truetype, falsetype) : pt();
  1457         if (condtype.constValue() != null &&
  1458                 truetype.constValue() != null &&
  1459                 falsetype.constValue() != null &&
  1460                 !owntype.hasTag(NONE)) {
  1461             //constant folding
  1462             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
  1464         result = check(tree, owntype, VAL, resultInfo);
  1466     //where
  1467         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
  1468             switch (tree.getTag()) {
  1469                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
  1470                               ((JCLiteral)tree).typetag == BOOLEAN ||
  1471                               ((JCLiteral)tree).typetag == BOT;
  1472                 case LAMBDA: case REFERENCE: return false;
  1473                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
  1474                 case CONDEXPR:
  1475                     JCConditional condTree = (JCConditional)tree;
  1476                     return isBooleanOrNumeric(env, condTree.truepart) &&
  1477                             isBooleanOrNumeric(env, condTree.falsepart);
  1478                 case APPLY:
  1479                     JCMethodInvocation speculativeMethodTree =
  1480                             (JCMethodInvocation)deferredAttr.attribSpeculative(tree, env, unknownExprInfo);
  1481                     Type owntype = TreeInfo.symbol(speculativeMethodTree.meth).type.getReturnType();
  1482                     return types.unboxedTypeOrType(owntype).isPrimitive();
  1483                 case NEWCLASS:
  1484                     JCExpression className =
  1485                             removeClassParams.translate(((JCNewClass)tree).clazz);
  1486                     JCExpression speculativeNewClassTree =
  1487                             (JCExpression)deferredAttr.attribSpeculative(className, env, unknownTypeInfo);
  1488                     return types.unboxedTypeOrType(speculativeNewClassTree.type).isPrimitive();
  1489                 default:
  1490                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo).type;
  1491                     speculativeType = types.unboxedTypeOrType(speculativeType);
  1492                     return speculativeType.isPrimitive();
  1495         //where
  1496             TreeTranslator removeClassParams = new TreeTranslator() {
  1497                 @Override
  1498                 public void visitTypeApply(JCTypeApply tree) {
  1499                     result = translate(tree.clazz);
  1501             };
  1503         /** Compute the type of a conditional expression, after
  1504          *  checking that it exists.  See JLS 15.25. Does not take into
  1505          *  account the special case where condition and both arms
  1506          *  are constants.
  1508          *  @param pos      The source position to be used for error
  1509          *                  diagnostics.
  1510          *  @param thentype The type of the expression's then-part.
  1511          *  @param elsetype The type of the expression's else-part.
  1512          */
  1513         private Type condType(DiagnosticPosition pos,
  1514                                Type thentype, Type elsetype) {
  1515             // If same type, that is the result
  1516             if (types.isSameType(thentype, elsetype))
  1517                 return thentype.baseType();
  1519             Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
  1520                 ? thentype : types.unboxedType(thentype);
  1521             Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
  1522                 ? elsetype : types.unboxedType(elsetype);
  1524             // Otherwise, if both arms can be converted to a numeric
  1525             // type, return the least numeric type that fits both arms
  1526             // (i.e. return larger of the two, or return int if one
  1527             // arm is short, the other is char).
  1528             if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
  1529                 // If one arm has an integer subrange type (i.e., byte,
  1530                 // short, or char), and the other is an integer constant
  1531                 // that fits into the subrange, return the subrange type.
  1532                 if (thenUnboxed.getTag().isStrictSubRangeOf(INT) &&
  1533                     elseUnboxed.hasTag(INT) &&
  1534                     types.isAssignable(elseUnboxed, thenUnboxed)) {
  1535                     return thenUnboxed.baseType();
  1537                 if (elseUnboxed.getTag().isStrictSubRangeOf(INT) &&
  1538                     thenUnboxed.hasTag(INT) &&
  1539                     types.isAssignable(thenUnboxed, elseUnboxed)) {
  1540                     return elseUnboxed.baseType();
  1543                 for (TypeTag tag : primitiveTags) {
  1544                     Type candidate = syms.typeOfTag[tag.ordinal()];
  1545                     if (types.isSubtype(thenUnboxed, candidate) &&
  1546                         types.isSubtype(elseUnboxed, candidate)) {
  1547                         return candidate;
  1552             // Those were all the cases that could result in a primitive
  1553             if (allowBoxing) {
  1554                 if (thentype.isPrimitive())
  1555                     thentype = types.boxedClass(thentype).type;
  1556                 if (elsetype.isPrimitive())
  1557                     elsetype = types.boxedClass(elsetype).type;
  1560             if (types.isSubtype(thentype, elsetype))
  1561                 return elsetype.baseType();
  1562             if (types.isSubtype(elsetype, thentype))
  1563                 return thentype.baseType();
  1565             if (!allowBoxing || thentype.hasTag(VOID) || elsetype.hasTag(VOID)) {
  1566                 log.error(pos, "neither.conditional.subtype",
  1567                           thentype, elsetype);
  1568                 return thentype.baseType();
  1571             // both are known to be reference types.  The result is
  1572             // lub(thentype,elsetype). This cannot fail, as it will
  1573             // always be possible to infer "Object" if nothing better.
  1574             return types.lub(thentype.baseType(), elsetype.baseType());
  1577     final static TypeTag[] primitiveTags = new TypeTag[]{
  1578         BYTE,
  1579         CHAR,
  1580         SHORT,
  1581         INT,
  1582         LONG,
  1583         FLOAT,
  1584         DOUBLE,
  1585         BOOLEAN,
  1586     };
  1588     public void visitIf(JCIf tree) {
  1589         attribExpr(tree.cond, env, syms.booleanType);
  1590         attribStat(tree.thenpart, env);
  1591         if (tree.elsepart != null)
  1592             attribStat(tree.elsepart, env);
  1593         chk.checkEmptyIf(tree);
  1594         result = null;
  1597     public void visitExec(JCExpressionStatement tree) {
  1598         //a fresh environment is required for 292 inference to work properly ---
  1599         //see Infer.instantiatePolymorphicSignatureInstance()
  1600         Env<AttrContext> localEnv = env.dup(tree);
  1601         attribExpr(tree.expr, localEnv);
  1602         result = null;
  1605     public void visitBreak(JCBreak tree) {
  1606         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
  1607         result = null;
  1610     public void visitContinue(JCContinue tree) {
  1611         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
  1612         result = null;
  1614     //where
  1615         /** Return the target of a break or continue statement, if it exists,
  1616          *  report an error if not.
  1617          *  Note: The target of a labelled break or continue is the
  1618          *  (non-labelled) statement tree referred to by the label,
  1619          *  not the tree representing the labelled statement itself.
  1621          *  @param pos     The position to be used for error diagnostics
  1622          *  @param tag     The tag of the jump statement. This is either
  1623          *                 Tree.BREAK or Tree.CONTINUE.
  1624          *  @param label   The label of the jump statement, or null if no
  1625          *                 label is given.
  1626          *  @param env     The environment current at the jump statement.
  1627          */
  1628         private JCTree findJumpTarget(DiagnosticPosition pos,
  1629                                     JCTree.Tag tag,
  1630                                     Name label,
  1631                                     Env<AttrContext> env) {
  1632             // Search environments outwards from the point of jump.
  1633             Env<AttrContext> env1 = env;
  1634             LOOP:
  1635             while (env1 != null) {
  1636                 switch (env1.tree.getTag()) {
  1637                     case LABELLED:
  1638                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
  1639                         if (label == labelled.label) {
  1640                             // If jump is a continue, check that target is a loop.
  1641                             if (tag == CONTINUE) {
  1642                                 if (!labelled.body.hasTag(DOLOOP) &&
  1643                                         !labelled.body.hasTag(WHILELOOP) &&
  1644                                         !labelled.body.hasTag(FORLOOP) &&
  1645                                         !labelled.body.hasTag(FOREACHLOOP))
  1646                                     log.error(pos, "not.loop.label", label);
  1647                                 // Found labelled statement target, now go inwards
  1648                                 // to next non-labelled tree.
  1649                                 return TreeInfo.referencedStatement(labelled);
  1650                             } else {
  1651                                 return labelled;
  1654                         break;
  1655                     case DOLOOP:
  1656                     case WHILELOOP:
  1657                     case FORLOOP:
  1658                     case FOREACHLOOP:
  1659                         if (label == null) return env1.tree;
  1660                         break;
  1661                     case SWITCH:
  1662                         if (label == null && tag == BREAK) return env1.tree;
  1663                         break;
  1664                     case LAMBDA:
  1665                     case METHODDEF:
  1666                     case CLASSDEF:
  1667                         break LOOP;
  1668                     default:
  1670                 env1 = env1.next;
  1672             if (label != null)
  1673                 log.error(pos, "undef.label", label);
  1674             else if (tag == CONTINUE)
  1675                 log.error(pos, "cont.outside.loop");
  1676             else
  1677                 log.error(pos, "break.outside.switch.loop");
  1678             return null;
  1681     public void visitReturn(JCReturn tree) {
  1682         // Check that there is an enclosing method which is
  1683         // nested within than the enclosing class.
  1684         if (env.info.returnResult == null) {
  1685             log.error(tree.pos(), "ret.outside.meth");
  1686         } else {
  1687             // Attribute return expression, if it exists, and check that
  1688             // it conforms to result type of enclosing method.
  1689             if (tree.expr != null) {
  1690                 if (env.info.returnResult.pt.hasTag(VOID)) {
  1691                     env.info.returnResult.checkContext.report(tree.expr.pos(),
  1692                               diags.fragment("unexpected.ret.val"));
  1694                 attribTree(tree.expr, env, env.info.returnResult);
  1695             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
  1696                     !env.info.returnResult.pt.hasTag(NONE)) {
  1697                 env.info.returnResult.checkContext.report(tree.pos(),
  1698                               diags.fragment("missing.ret.val"));
  1701         result = null;
  1704     public void visitThrow(JCThrow tree) {
  1705         Type owntype = attribExpr(tree.expr, env, allowPoly ? Type.noType : syms.throwableType);
  1706         if (allowPoly) {
  1707             chk.checkType(tree, owntype, syms.throwableType);
  1709         result = null;
  1712     public void visitAssert(JCAssert tree) {
  1713         attribExpr(tree.cond, env, syms.booleanType);
  1714         if (tree.detail != null) {
  1715             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
  1717         result = null;
  1720      /** Visitor method for method invocations.
  1721      *  NOTE: The method part of an application will have in its type field
  1722      *        the return type of the method, not the method's type itself!
  1723      */
  1724     public void visitApply(JCMethodInvocation tree) {
  1725         // The local environment of a method application is
  1726         // a new environment nested in the current one.
  1727         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
  1729         // The types of the actual method arguments.
  1730         List<Type> argtypes;
  1732         // The types of the actual method type arguments.
  1733         List<Type> typeargtypes = null;
  1735         Name methName = TreeInfo.name(tree.meth);
  1737         boolean isConstructorCall =
  1738             methName == names._this || methName == names._super;
  1740         ListBuffer<Type> argtypesBuf = ListBuffer.lb();
  1741         if (isConstructorCall) {
  1742             // We are seeing a ...this(...) or ...super(...) call.
  1743             // Check that this is the first statement in a constructor.
  1744             if (checkFirstConstructorStat(tree, env)) {
  1746                 // Record the fact
  1747                 // that this is a constructor call (using isSelfCall).
  1748                 localEnv.info.isSelfCall = true;
  1750                 // Attribute arguments, yielding list of argument types.
  1751                 attribArgs(tree.args, localEnv, argtypesBuf);
  1752                 argtypes = argtypesBuf.toList();
  1753                 typeargtypes = attribTypes(tree.typeargs, localEnv);
  1755                 // Variable `site' points to the class in which the called
  1756                 // constructor is defined.
  1757                 Type site = env.enclClass.sym.type;
  1758                 if (methName == names._super) {
  1759                     if (site == syms.objectType) {
  1760                         log.error(tree.meth.pos(), "no.superclass", site);
  1761                         site = types.createErrorType(syms.objectType);
  1762                     } else {
  1763                         site = types.supertype(site);
  1767                 if (site.hasTag(CLASS)) {
  1768                     Type encl = site.getEnclosingType();
  1769                     while (encl != null && encl.hasTag(TYPEVAR))
  1770                         encl = encl.getUpperBound();
  1771                     if (encl.hasTag(CLASS)) {
  1772                         // we are calling a nested class
  1774                         if (tree.meth.hasTag(SELECT)) {
  1775                             JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
  1777                             // We are seeing a prefixed call, of the form
  1778                             //     <expr>.super(...).
  1779                             // Check that the prefix expression conforms
  1780                             // to the outer instance type of the class.
  1781                             chk.checkRefType(qualifier.pos(),
  1782                                              attribExpr(qualifier, localEnv,
  1783                                                         encl));
  1784                         } else if (methName == names._super) {
  1785                             // qualifier omitted; check for existence
  1786                             // of an appropriate implicit qualifier.
  1787                             rs.resolveImplicitThis(tree.meth.pos(),
  1788                                                    localEnv, site, true);
  1790                     } else if (tree.meth.hasTag(SELECT)) {
  1791                         log.error(tree.meth.pos(), "illegal.qual.not.icls",
  1792                                   site.tsym);
  1795                     // if we're calling a java.lang.Enum constructor,
  1796                     // prefix the implicit String and int parameters
  1797                     if (site.tsym == syms.enumSym && allowEnums)
  1798                         argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
  1800                     // Resolve the called constructor under the assumption
  1801                     // that we are referring to a superclass instance of the
  1802                     // current instance (JLS ???).
  1803                     boolean selectSuperPrev = localEnv.info.selectSuper;
  1804                     localEnv.info.selectSuper = true;
  1805                     localEnv.info.pendingResolutionPhase = null;
  1806                     Symbol sym = rs.resolveConstructor(
  1807                         tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
  1808                     localEnv.info.selectSuper = selectSuperPrev;
  1810                     // Set method symbol to resolved constructor...
  1811                     TreeInfo.setSymbol(tree.meth, sym);
  1813                     // ...and check that it is legal in the current context.
  1814                     // (this will also set the tree's type)
  1815                     Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
  1816                     checkId(tree.meth, site, sym, localEnv, new ResultInfo(MTH, mpt));
  1818                 // Otherwise, `site' is an error type and we do nothing
  1820             result = tree.type = syms.voidType;
  1821         } else {
  1822             // Otherwise, we are seeing a regular method call.
  1823             // Attribute the arguments, yielding list of argument types, ...
  1824             int kind = attribArgs(tree.args, localEnv, argtypesBuf);
  1825             argtypes = argtypesBuf.toList();
  1826             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
  1828             // ... and attribute the method using as a prototype a methodtype
  1829             // whose formal argument types is exactly the list of actual
  1830             // arguments (this will also set the method symbol).
  1831             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
  1832             localEnv.info.pendingResolutionPhase = null;
  1833             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
  1835             // Compute the result type.
  1836             Type restype = mtype.getReturnType();
  1837             if (restype.hasTag(WILDCARD))
  1838                 throw new AssertionError(mtype);
  1840             Type qualifier = (tree.meth.hasTag(SELECT))
  1841                     ? ((JCFieldAccess) tree.meth).selected.type
  1842                     : env.enclClass.sym.type;
  1843             restype = adjustMethodReturnType(qualifier, methName, argtypes, restype);
  1845             chk.checkRefTypes(tree.typeargs, typeargtypes);
  1847             // Check that value of resulting type is admissible in the
  1848             // current context.  Also, capture the return type
  1849             result = check(tree, capture(restype), VAL, resultInfo);
  1851         chk.validate(tree.typeargs, localEnv);
  1853     //where
  1854         Type adjustMethodReturnType(Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
  1855             if (allowCovariantReturns &&
  1856                     methodName == names.clone &&
  1857                 types.isArray(qualifierType)) {
  1858                 // as a special case, array.clone() has a result that is
  1859                 // the same as static type of the array being cloned
  1860                 return qualifierType;
  1861             } else if (allowGenerics &&
  1862                     methodName == names.getClass &&
  1863                     argtypes.isEmpty()) {
  1864                 // as a special case, x.getClass() has type Class<? extends |X|>
  1865                 return new ClassType(restype.getEnclosingType(),
  1866                               List.<Type>of(new WildcardType(types.erasure(qualifierType),
  1867                                                                BoundKind.EXTENDS,
  1868                                                                syms.boundClass)),
  1869                               restype.tsym);
  1870             } else {
  1871                 return restype;
  1875         /** Check that given application node appears as first statement
  1876          *  in a constructor call.
  1877          *  @param tree   The application node
  1878          *  @param env    The environment current at the application.
  1879          */
  1880         boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
  1881             JCMethodDecl enclMethod = env.enclMethod;
  1882             if (enclMethod != null && enclMethod.name == names.init) {
  1883                 JCBlock body = enclMethod.body;
  1884                 if (body.stats.head.hasTag(EXEC) &&
  1885                     ((JCExpressionStatement) body.stats.head).expr == tree)
  1886                     return true;
  1888             log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
  1889                       TreeInfo.name(tree.meth));
  1890             return false;
  1893         /** Obtain a method type with given argument types.
  1894          */
  1895         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
  1896             MethodType mt = new MethodType(argtypes, restype, List.<Type>nil(), syms.methodClass);
  1897             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
  1900     public void visitNewClass(final JCNewClass tree) {
  1901         Type owntype = types.createErrorType(tree.type);
  1903         // The local environment of a class creation is
  1904         // a new environment nested in the current one.
  1905         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
  1907         // The anonymous inner class definition of the new expression,
  1908         // if one is defined by it.
  1909         JCClassDecl cdef = tree.def;
  1911         // If enclosing class is given, attribute it, and
  1912         // complete class name to be fully qualified
  1913         JCExpression clazz = tree.clazz; // Class field following new
  1914         JCExpression clazzid;            // Identifier in class field
  1915         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
  1916         annoclazzid = null;
  1918         if (clazz.hasTag(TYPEAPPLY)) {
  1919             clazzid = ((JCTypeApply) clazz).clazz;
  1920             if (clazzid.hasTag(ANNOTATED_TYPE)) {
  1921                 annoclazzid = (JCAnnotatedType) clazzid;
  1922                 clazzid = annoclazzid.underlyingType;
  1924         } else {
  1925             if (clazz.hasTag(ANNOTATED_TYPE)) {
  1926                 annoclazzid = (JCAnnotatedType) clazz;
  1927                 clazzid = annoclazzid.underlyingType;
  1928             } else {
  1929                 clazzid = clazz;
  1933         JCExpression clazzid1 = clazzid; // The same in fully qualified form
  1935         if (tree.encl != null) {
  1936             // We are seeing a qualified new, of the form
  1937             //    <expr>.new C <...> (...) ...
  1938             // In this case, we let clazz stand for the name of the
  1939             // allocated class C prefixed with the type of the qualifier
  1940             // expression, so that we can
  1941             // resolve it with standard techniques later. I.e., if
  1942             // <expr> has type T, then <expr>.new C <...> (...)
  1943             // yields a clazz T.C.
  1944             Type encltype = chk.checkRefType(tree.encl.pos(),
  1945                                              attribExpr(tree.encl, env));
  1946             // TODO 308: in <expr>.new C, do we also want to add the type annotations
  1947             // from expr to the combined type, or not? Yes, do this.
  1948             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
  1949                                                  ((JCIdent) clazzid).name);
  1951             EndPosTable endPosTable = this.env.toplevel.endPositions;
  1952             endPosTable.storeEnd(clazzid1, tree.getEndPosition(endPosTable));
  1953             if (clazz.hasTag(ANNOTATED_TYPE)) {
  1954                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
  1955                 List<JCAnnotation> annos = annoType.annotations;
  1957                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
  1958                     clazzid1 = make.at(tree.pos).
  1959                         TypeApply(clazzid1,
  1960                                   ((JCTypeApply) clazz).arguments);
  1963                 clazzid1 = make.at(tree.pos).
  1964                     AnnotatedType(annos, clazzid1);
  1965             } else if (clazz.hasTag(TYPEAPPLY)) {
  1966                 clazzid1 = make.at(tree.pos).
  1967                     TypeApply(clazzid1,
  1968                               ((JCTypeApply) clazz).arguments);
  1971             clazz = clazzid1;
  1974         // Attribute clazz expression and store
  1975         // symbol + type back into the attributed tree.
  1976         Type clazztype = TreeInfo.isEnumInit(env.tree) ?
  1977             attribIdentAsEnumType(env, (JCIdent)clazz) :
  1978             attribType(clazz, env);
  1980         clazztype = chk.checkDiamond(tree, clazztype);
  1981         chk.validate(clazz, localEnv);
  1982         if (tree.encl != null) {
  1983             // We have to work in this case to store
  1984             // symbol + type back into the attributed tree.
  1985             tree.clazz.type = clazztype;
  1986             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
  1987             clazzid.type = ((JCIdent) clazzid).sym.type;
  1988             if (annoclazzid != null) {
  1989                 annoclazzid.type = clazzid.type;
  1991             if (!clazztype.isErroneous()) {
  1992                 if (cdef != null && clazztype.tsym.isInterface()) {
  1993                     log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
  1994                 } else if (clazztype.tsym.isStatic()) {
  1995                     log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
  1998         } else if (!clazztype.tsym.isInterface() &&
  1999                    clazztype.getEnclosingType().hasTag(CLASS)) {
  2000             // Check for the existence of an apropos outer instance
  2001             rs.resolveImplicitThis(tree.pos(), env, clazztype);
  2004         // Attribute constructor arguments.
  2005         ListBuffer<Type> argtypesBuf = ListBuffer.lb();
  2006         int pkind = attribArgs(tree.args, localEnv, argtypesBuf);
  2007         List<Type> argtypes = argtypesBuf.toList();
  2008         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
  2010         // If we have made no mistakes in the class type...
  2011         if (clazztype.hasTag(CLASS)) {
  2012             // Enums may not be instantiated except implicitly
  2013             if (allowEnums &&
  2014                 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
  2015                 (!env.tree.hasTag(VARDEF) ||
  2016                  (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
  2017                  ((JCVariableDecl) env.tree).init != tree))
  2018                 log.error(tree.pos(), "enum.cant.be.instantiated");
  2019             // Check that class is not abstract
  2020             if (cdef == null &&
  2021                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
  2022                 log.error(tree.pos(), "abstract.cant.be.instantiated",
  2023                           clazztype.tsym);
  2024             } else if (cdef != null && clazztype.tsym.isInterface()) {
  2025                 // Check that no constructor arguments are given to
  2026                 // anonymous classes implementing an interface
  2027                 if (!argtypes.isEmpty())
  2028                     log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
  2030                 if (!typeargtypes.isEmpty())
  2031                     log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
  2033                 // Error recovery: pretend no arguments were supplied.
  2034                 argtypes = List.nil();
  2035                 typeargtypes = List.nil();
  2036             } else if (TreeInfo.isDiamond(tree)) {
  2037                 ClassType site = new ClassType(clazztype.getEnclosingType(),
  2038                             clazztype.tsym.type.getTypeArguments(),
  2039                             clazztype.tsym);
  2041                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
  2042                 diamondEnv.info.selectSuper = cdef != null;
  2043                 diamondEnv.info.pendingResolutionPhase = null;
  2045                 //if the type of the instance creation expression is a class type
  2046                 //apply method resolution inference (JLS 15.12.2.7). The return type
  2047                 //of the resolved constructor will be a partially instantiated type
  2048                 Symbol constructor = rs.resolveDiamond(tree.pos(),
  2049                             diamondEnv,
  2050                             site,
  2051                             argtypes,
  2052                             typeargtypes);
  2053                 tree.constructor = constructor.baseSymbol();
  2055                 final TypeSymbol csym = clazztype.tsym;
  2056                 ResultInfo diamondResult = new ResultInfo(MTH, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes), new Check.NestedCheckContext(resultInfo.checkContext) {
  2057                     @Override
  2058                     public void report(DiagnosticPosition _unused, JCDiagnostic details) {
  2059                         enclosingContext.report(tree.clazz,
  2060                                 diags.fragment("cant.apply.diamond.1", diags.fragment("diamond", csym), details));
  2062                 });
  2063                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
  2064                 constructorType = checkId(tree, site,
  2065                         constructor,
  2066                         diamondEnv,
  2067                         diamondResult);
  2069                 tree.clazz.type = types.createErrorType(clazztype);
  2070                 if (!constructorType.isErroneous()) {
  2071                     tree.clazz.type = clazztype = constructorType.getReturnType();
  2072                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
  2074                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
  2077             // Resolve the called constructor under the assumption
  2078             // that we are referring to a superclass instance of the
  2079             // current instance (JLS ???).
  2080             else {
  2081                 //the following code alters some of the fields in the current
  2082                 //AttrContext - hence, the current context must be dup'ed in
  2083                 //order to avoid downstream failures
  2084                 Env<AttrContext> rsEnv = localEnv.dup(tree);
  2085                 rsEnv.info.selectSuper = cdef != null;
  2086                 rsEnv.info.pendingResolutionPhase = null;
  2087                 tree.constructor = rs.resolveConstructor(
  2088                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
  2089                 if (cdef == null) { //do not check twice!
  2090                     tree.constructorType = checkId(tree,
  2091                             clazztype,
  2092                             tree.constructor,
  2093                             rsEnv,
  2094                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes)));
  2095                     if (rsEnv.info.lastResolveVarargs())
  2096                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
  2098                 if (cdef == null &&
  2099                         !clazztype.isErroneous() &&
  2100                         clazztype.getTypeArguments().nonEmpty() &&
  2101                         findDiamonds) {
  2102                     findDiamond(localEnv, tree, clazztype);
  2106             if (cdef != null) {
  2107                 // We are seeing an anonymous class instance creation.
  2108                 // In this case, the class instance creation
  2109                 // expression
  2110                 //
  2111                 //    E.new <typeargs1>C<typargs2>(args) { ... }
  2112                 //
  2113                 // is represented internally as
  2114                 //
  2115                 //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
  2116                 //
  2117                 // This expression is then *transformed* as follows:
  2118                 //
  2119                 // (1) add a STATIC flag to the class definition
  2120                 //     if the current environment is static
  2121                 // (2) add an extends or implements clause
  2122                 // (3) add a constructor.
  2123                 //
  2124                 // For instance, if C is a class, and ET is the type of E,
  2125                 // the expression
  2126                 //
  2127                 //    E.new <typeargs1>C<typargs2>(args) { ... }
  2128                 //
  2129                 // is translated to (where X is a fresh name and typarams is the
  2130                 // parameter list of the super constructor):
  2131                 //
  2132                 //   new <typeargs1>X(<*nullchk*>E, args) where
  2133                 //     X extends C<typargs2> {
  2134                 //       <typarams> X(ET e, args) {
  2135                 //         e.<typeargs1>super(args)
  2136                 //       }
  2137                 //       ...
  2138                 //     }
  2139                 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
  2141                 if (clazztype.tsym.isInterface()) {
  2142                     cdef.implementing = List.of(clazz);
  2143                 } else {
  2144                     cdef.extending = clazz;
  2147                 attribStat(cdef, localEnv);
  2149                 checkLambdaCandidate(tree, cdef.sym, clazztype);
  2151                 // If an outer instance is given,
  2152                 // prefix it to the constructor arguments
  2153                 // and delete it from the new expression
  2154                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
  2155                     tree.args = tree.args.prepend(makeNullCheck(tree.encl));
  2156                     argtypes = argtypes.prepend(tree.encl.type);
  2157                     tree.encl = null;
  2160                 // Reassign clazztype and recompute constructor.
  2161                 clazztype = cdef.sym.type;
  2162                 Symbol sym = tree.constructor = rs.resolveConstructor(
  2163                     tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
  2164                 Assert.check(sym.kind < AMBIGUOUS);
  2165                 tree.constructor = sym;
  2166                 tree.constructorType = checkId(tree,
  2167                     clazztype,
  2168                     tree.constructor,
  2169                     localEnv,
  2170                     new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes)));
  2171             } else {
  2172                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
  2173                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
  2174                             tree.clazz.type.tsym);
  2178             if (tree.constructor != null && tree.constructor.kind == MTH)
  2179                 owntype = clazztype;
  2181         result = check(tree, owntype, VAL, resultInfo);
  2182         chk.validate(tree.typeargs, localEnv);
  2184     //where
  2185         void findDiamond(Env<AttrContext> env, JCNewClass tree, Type clazztype) {
  2186             JCTypeApply ta = (JCTypeApply)tree.clazz;
  2187             List<JCExpression> prevTypeargs = ta.arguments;
  2188             try {
  2189                 //create a 'fake' diamond AST node by removing type-argument trees
  2190                 ta.arguments = List.nil();
  2191                 ResultInfo findDiamondResult = new ResultInfo(VAL,
  2192                         resultInfo.checkContext.inferenceContext().free(resultInfo.pt) ? Type.noType : pt());
  2193                 Type inferred = deferredAttr.attribSpeculative(tree, env, findDiamondResult).type;
  2194                 Type polyPt = allowPoly ?
  2195                         syms.objectType :
  2196                         clazztype;
  2197                 if (!inferred.isErroneous() &&
  2198                     (allowPoly && pt() == Infer.anyPoly ?
  2199                         types.isSameType(inferred, clazztype) :
  2200                         types.isAssignable(inferred, pt().hasTag(NONE) ? polyPt : pt(), types.noWarnings))) {
  2201                     String key = types.isSameType(clazztype, inferred) ?
  2202                         "diamond.redundant.args" :
  2203                         "diamond.redundant.args.1";
  2204                     log.warning(tree.clazz.pos(), key, clazztype, inferred);
  2206             } finally {
  2207                 ta.arguments = prevTypeargs;
  2211             private void checkLambdaCandidate(JCNewClass tree, ClassSymbol csym, Type clazztype) {
  2212                 if (allowLambda &&
  2213                         identifyLambdaCandidate &&
  2214                         clazztype.hasTag(CLASS) &&
  2215                         !pt().hasTag(NONE) &&
  2216                         types.isFunctionalInterface(clazztype.tsym)) {
  2217                     Symbol descriptor = types.findDescriptorSymbol(clazztype.tsym);
  2218                     int count = 0;
  2219                     boolean found = false;
  2220                     for (Symbol sym : csym.members().getElements()) {
  2221                         if ((sym.flags() & SYNTHETIC) != 0 ||
  2222                                 sym.isConstructor()) continue;
  2223                         count++;
  2224                         if (sym.kind != MTH ||
  2225                                 !sym.name.equals(descriptor.name)) continue;
  2226                         Type mtype = types.memberType(clazztype, sym);
  2227                         if (types.overrideEquivalent(mtype, types.memberType(clazztype, descriptor))) {
  2228                             found = true;
  2231                     if (found && count == 1) {
  2232                         log.note(tree.def, "potential.lambda.found");
  2237     private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
  2238             Symbol sym) {
  2239         // Ensure that no declaration annotations are present.
  2240         // Note that a tree type might be an AnnotatedType with
  2241         // empty annotations, if only declaration annotations were given.
  2242         // This method will raise an error for such a type.
  2243         for (JCAnnotation ai : annotations) {
  2244             if (TypeAnnotations.annotationType(syms, names, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
  2245                 log.error(ai.pos(), "annotation.type.not.applicable");
  2251     /** Make an attributed null check tree.
  2252      */
  2253     public JCExpression makeNullCheck(JCExpression arg) {
  2254         // optimization: X.this is never null; skip null check
  2255         Name name = TreeInfo.name(arg);
  2256         if (name == names._this || name == names._super) return arg;
  2258         JCTree.Tag optag = NULLCHK;
  2259         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
  2260         tree.operator = syms.nullcheck;
  2261         tree.type = arg.type;
  2262         return tree;
  2265     public void visitNewArray(JCNewArray tree) {
  2266         Type owntype = types.createErrorType(tree.type);
  2267         Env<AttrContext> localEnv = env.dup(tree);
  2268         Type elemtype;
  2269         if (tree.elemtype != null) {
  2270             elemtype = attribType(tree.elemtype, localEnv);
  2271             chk.validate(tree.elemtype, localEnv);
  2272             owntype = elemtype;
  2273             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
  2274                 attribExpr(l.head, localEnv, syms.intType);
  2275                 owntype = new ArrayType(owntype, syms.arrayClass);
  2277             if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
  2278                 checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
  2279                         tree.elemtype.type.tsym);
  2281         } else {
  2282             // we are seeing an untyped aggregate { ... }
  2283             // this is allowed only if the prototype is an array
  2284             if (pt().hasTag(ARRAY)) {
  2285                 elemtype = types.elemtype(pt());
  2286             } else {
  2287                 if (!pt().hasTag(ERROR)) {
  2288                     log.error(tree.pos(), "illegal.initializer.for.type",
  2289                               pt());
  2291                 elemtype = types.createErrorType(pt());
  2294         if (tree.elems != null) {
  2295             attribExprs(tree.elems, localEnv, elemtype);
  2296             owntype = new ArrayType(elemtype, syms.arrayClass);
  2298         if (!types.isReifiable(elemtype))
  2299             log.error(tree.pos(), "generic.array.creation");
  2300         result = check(tree, owntype, VAL, resultInfo);
  2303     /*
  2304      * A lambda expression can only be attributed when a target-type is available.
  2305      * In addition, if the target-type is that of a functional interface whose
  2306      * descriptor contains inference variables in argument position the lambda expression
  2307      * is 'stuck' (see DeferredAttr).
  2308      */
  2309     @Override
  2310     public void visitLambda(final JCLambda that) {
  2311         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
  2312             if (pt().hasTag(NONE)) {
  2313                 //lambda only allowed in assignment or method invocation/cast context
  2314                 log.error(that.pos(), "unexpected.lambda");
  2316             result = that.type = types.createErrorType(pt());
  2317             return;
  2319         //create an environment for attribution of the lambda expression
  2320         final Env<AttrContext> localEnv = lambdaEnv(that, env);
  2321         boolean needsRecovery =
  2322                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
  2323         try {
  2324             Type target = pt();
  2325             List<Type> explicitParamTypes = null;
  2326             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
  2327                 //attribute lambda parameters
  2328                 attribStats(that.params, localEnv);
  2329                 explicitParamTypes = TreeInfo.types(that.params);
  2330                 target = infer.instantiateFunctionalInterface(that, target, explicitParamTypes, resultInfo.checkContext);
  2333             Type lambdaType;
  2334             if (pt() != Type.recoveryType) {
  2335                 target = targetChecker.visit(target, that);
  2336                 lambdaType = types.findDescriptorType(target);
  2337             } else {
  2338                 target = Type.recoveryType;
  2339                 lambdaType = fallbackDescriptorType(that);
  2342             setFunctionalInfo(localEnv, that, pt(), lambdaType, target, resultInfo.checkContext);
  2344             if (lambdaType.hasTag(FORALL)) {
  2345                 //lambda expression target desc cannot be a generic method
  2346                 resultInfo.checkContext.report(that, diags.fragment("invalid.generic.lambda.target",
  2347                         lambdaType, kindName(target.tsym), target.tsym));
  2348                 result = that.type = types.createErrorType(pt());
  2349                 return;
  2352             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
  2353                 //add param type info in the AST
  2354                 List<Type> actuals = lambdaType.getParameterTypes();
  2355                 List<JCVariableDecl> params = that.params;
  2357                 boolean arityMismatch = false;
  2359                 while (params.nonEmpty()) {
  2360                     if (actuals.isEmpty()) {
  2361                         //not enough actuals to perform lambda parameter inference
  2362                         arityMismatch = true;
  2364                     //reset previously set info
  2365                     Type argType = arityMismatch ?
  2366                             syms.errType :
  2367                             actuals.head;
  2368                     params.head.vartype = make.at(params.head).Type(argType);
  2369                     params.head.sym = null;
  2370                     actuals = actuals.isEmpty() ?
  2371                             actuals :
  2372                             actuals.tail;
  2373                     params = params.tail;
  2376                 //attribute lambda parameters
  2377                 attribStats(that.params, localEnv);
  2379                 if (arityMismatch) {
  2380                     resultInfo.checkContext.report(that, diags.fragment("incompatible.arg.types.in.lambda"));
  2381                         result = that.type = types.createErrorType(target);
  2382                         return;
  2386             //from this point on, no recovery is needed; if we are in assignment context
  2387             //we will be able to attribute the whole lambda body, regardless of errors;
  2388             //if we are in a 'check' method context, and the lambda is not compatible
  2389             //with the target-type, it will be recovered anyway in Attr.checkId
  2390             needsRecovery = false;
  2392             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
  2393                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
  2394                     new FunctionalReturnContext(resultInfo.checkContext);
  2396             ResultInfo bodyResultInfo = lambdaType.getReturnType() == Type.recoveryType ?
  2397                 recoveryInfo :
  2398                 new ResultInfo(VAL, lambdaType.getReturnType(), funcContext);
  2399             localEnv.info.returnResult = bodyResultInfo;
  2401             Log.DeferredDiagnosticHandler lambdaDeferredHandler = new Log.DeferredDiagnosticHandler(log);
  2402             try {
  2403                 if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
  2404                     attribTree(that.getBody(), localEnv, bodyResultInfo);
  2405                 } else {
  2406                     JCBlock body = (JCBlock)that.body;
  2407                     attribStats(body.stats, localEnv);
  2410                 if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.SPECULATIVE) {
  2411                     //check for errors in lambda body
  2412                     for (JCDiagnostic deferredDiag : lambdaDeferredHandler.getDiagnostics()) {
  2413                         if (deferredDiag.getKind() == JCDiagnostic.Kind.ERROR) {
  2414                             resultInfo.checkContext
  2415                                     .report(that, diags.fragment("bad.arg.types.in.lambda", TreeInfo.types(that.params),
  2416                                     deferredDiag)); //hidden diag parameter
  2417                             //we mark the lambda as erroneous - this is crucial in the recovery step
  2418                             //as parameter-dependent type error won't be reported in that stage,
  2419                             //meaning that a lambda will be deemed erroeneous only if there is
  2420                             //a target-independent error (which will cause method diagnostic
  2421                             //to be skipped).
  2422                             result = that.type = types.createErrorType(target);
  2423                             return;
  2427             } finally {
  2428                 lambdaDeferredHandler.reportDeferredDiagnostics();
  2429                 log.popDiagnosticHandler(lambdaDeferredHandler);
  2432             result = check(that, target, VAL, resultInfo);
  2434             boolean isSpeculativeRound =
  2435                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
  2437             preFlow(that);
  2438             flow.analyzeLambda(env, that, make, isSpeculativeRound);
  2440             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext, isSpeculativeRound);
  2442             if (!isSpeculativeRound) {
  2443                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, target);
  2445             result = check(that, target, VAL, resultInfo);
  2446         } catch (Types.FunctionDescriptorLookupError ex) {
  2447             JCDiagnostic cause = ex.getDiagnostic();
  2448             resultInfo.checkContext.report(that, cause);
  2449             result = that.type = types.createErrorType(pt());
  2450             return;
  2451         } finally {
  2452             localEnv.info.scope.leave();
  2453             if (needsRecovery) {
  2454                 attribTree(that, env, recoveryInfo);
  2458     //where
  2459         void preFlow(JCLambda tree) {
  2460             new PostAttrAnalyzer() {
  2461                 @Override
  2462                 public void scan(JCTree tree) {
  2463                     if (tree == null ||
  2464                             (tree.type != null &&
  2465                             tree.type == Type.stuckType)) {
  2466                         //don't touch stuck expressions!
  2467                         return;
  2469                     super.scan(tree);
  2471             }.scan(tree);
  2474         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
  2476             @Override
  2477             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
  2478                 return t.isCompound() ?
  2479                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
  2482             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
  2483                 Symbol desc = types.findDescriptorSymbol(makeNotionalInterface(ict));
  2484                 Type target = null;
  2485                 for (Type bound : ict.getExplicitComponents()) {
  2486                     TypeSymbol boundSym = bound.tsym;
  2487                     if (types.isFunctionalInterface(boundSym) &&
  2488                             types.findDescriptorSymbol(boundSym) == desc) {
  2489                         target = bound;
  2490                     } else if (!boundSym.isInterface() || (boundSym.flags() & ANNOTATION) != 0) {
  2491                         //bound must be an interface
  2492                         reportIntersectionError(pos, "not.an.intf.component", boundSym);
  2495                 return target != null ?
  2496                         target :
  2497                         ict.getExplicitComponents().head; //error recovery
  2500             private TypeSymbol makeNotionalInterface(IntersectionClassType ict) {
  2501                 ListBuffer<Type> targs = ListBuffer.lb();
  2502                 ListBuffer<Type> supertypes = ListBuffer.lb();
  2503                 for (Type i : ict.interfaces_field) {
  2504                     if (i.isParameterized()) {
  2505                         targs.appendList(i.tsym.type.allparams());
  2507                     supertypes.append(i.tsym.type);
  2509                 IntersectionClassType notionalIntf =
  2510                         (IntersectionClassType)types.makeCompoundType(supertypes.toList());
  2511                 notionalIntf.allparams_field = targs.toList();
  2512                 notionalIntf.tsym.flags_field |= INTERFACE;
  2513                 return notionalIntf.tsym;
  2516             private void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) {
  2517                 resultInfo.checkContext.report(pos, diags.fragment("bad.intersection.target.for.functional.expr",
  2518                         diags.fragment(key, args)));
  2520         };
  2522         private Type fallbackDescriptorType(JCExpression tree) {
  2523             switch (tree.getTag()) {
  2524                 case LAMBDA:
  2525                     JCLambda lambda = (JCLambda)tree;
  2526                     List<Type> argtypes = List.nil();
  2527                     for (JCVariableDecl param : lambda.params) {
  2528                         argtypes = param.vartype != null ?
  2529                                 argtypes.append(param.vartype.type) :
  2530                                 argtypes.append(syms.errType);
  2532                     return new MethodType(argtypes, Type.recoveryType,
  2533                             List.of(syms.throwableType), syms.methodClass);
  2534                 case REFERENCE:
  2535                     return new MethodType(List.<Type>nil(), Type.recoveryType,
  2536                             List.of(syms.throwableType), syms.methodClass);
  2537                 default:
  2538                     Assert.error("Cannot get here!");
  2540             return null;
  2543         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
  2544                 final InferenceContext inferenceContext, final Type... ts) {
  2545             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
  2548         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
  2549                 final InferenceContext inferenceContext, final List<Type> ts) {
  2550             if (inferenceContext.free(ts)) {
  2551                 inferenceContext.addFreeTypeListener(ts, new FreeTypeListener() {
  2552                     @Override
  2553                     public void typesInferred(InferenceContext inferenceContext) {
  2554                         checkAccessibleTypes(pos, env, inferenceContext, inferenceContext.asInstTypes(ts));
  2556                 });
  2557             } else {
  2558                 for (Type t : ts) {
  2559                     rs.checkAccessibleType(env, t);
  2564         /**
  2565          * Lambda/method reference have a special check context that ensures
  2566          * that i.e. a lambda return type is compatible with the expected
  2567          * type according to both the inherited context and the assignment
  2568          * context.
  2569          */
  2570         class FunctionalReturnContext extends Check.NestedCheckContext {
  2572             FunctionalReturnContext(CheckContext enclosingContext) {
  2573                 super(enclosingContext);
  2576             @Override
  2577             public boolean compatible(Type found, Type req, Warner warn) {
  2578                 //return type must be compatible in both current context and assignment context
  2579                 return chk.basicHandler.compatible(found, inferenceContext().asFree(req), warn);
  2582             @Override
  2583             public void report(DiagnosticPosition pos, JCDiagnostic details) {
  2584                 enclosingContext.report(pos, diags.fragment("incompatible.ret.type.in.lambda", details));
  2588         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
  2590             JCExpression expr;
  2592             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
  2593                 super(enclosingContext);
  2594                 this.expr = expr;
  2597             @Override
  2598             public boolean compatible(Type found, Type req, Warner warn) {
  2599                 //a void return is compatible with an expression statement lambda
  2600                 return TreeInfo.isExpressionStatement(expr) && req.hasTag(VOID) ||
  2601                         super.compatible(found, req, warn);
  2605         /**
  2606         * Lambda compatibility. Check that given return types, thrown types, parameter types
  2607         * are compatible with the expected functional interface descriptor. This means that:
  2608         * (i) parameter types must be identical to those of the target descriptor; (ii) return
  2609         * types must be compatible with the return type of the expected descriptor;
  2610         * (iii) thrown types must be 'included' in the thrown types list of the expected
  2611         * descriptor.
  2612         */
  2613         private void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext, boolean speculativeAttr) {
  2614             Type returnType = checkContext.inferenceContext().asFree(descriptor.getReturnType());
  2616             //return values have already been checked - but if lambda has no return
  2617             //values, we must ensure that void/value compatibility is correct;
  2618             //this amounts at checking that, if a lambda body can complete normally,
  2619             //the descriptor's return type must be void
  2620             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
  2621                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
  2622                 checkContext.report(tree, diags.fragment("incompatible.ret.type.in.lambda",
  2623                         diags.fragment("missing.ret.val", returnType)));
  2626             List<Type> argTypes = checkContext.inferenceContext().asFree(descriptor.getParameterTypes());
  2627             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
  2628                 checkContext.report(tree, diags.fragment("incompatible.arg.types.in.lambda"));
  2631             if (!speculativeAttr) {
  2632                 List<Type> thrownTypes = checkContext.inferenceContext().asFree(descriptor.getThrownTypes());
  2633                 if (chk.unhandled(tree.inferredThrownTypes == null ? List.<Type>nil() : tree.inferredThrownTypes, thrownTypes).nonEmpty()) {
  2634                     log.error(tree, "incompatible.thrown.types.in.lambda", tree.inferredThrownTypes);
  2639         private Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
  2640             Env<AttrContext> lambdaEnv;
  2641             Symbol owner = env.info.scope.owner;
  2642             if (owner.kind == VAR && owner.owner.kind == TYP) {
  2643                 //field initializer
  2644                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared()));
  2645                 lambdaEnv.info.scope.owner =
  2646                     new MethodSymbol((owner.flags() & STATIC) | BLOCK, names.empty, null,
  2647                                      env.info.scope.owner);
  2648             } else {
  2649                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
  2651             return lambdaEnv;
  2654     @Override
  2655     public void visitReference(final JCMemberReference that) {
  2656         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
  2657             if (pt().hasTag(NONE)) {
  2658                 //method reference only allowed in assignment or method invocation/cast context
  2659                 log.error(that.pos(), "unexpected.mref");
  2661             result = that.type = types.createErrorType(pt());
  2662             return;
  2664         final Env<AttrContext> localEnv = env.dup(that);
  2665         try {
  2666             //attribute member reference qualifier - if this is a constructor
  2667             //reference, the expected kind must be a type
  2668             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
  2670             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
  2671                 exprType = chk.checkConstructorRefType(that.expr, exprType);
  2674             if (exprType.isErroneous()) {
  2675                 //if the qualifier expression contains problems,
  2676                 //give up attribution of method reference
  2677                 result = that.type = exprType;
  2678                 return;
  2681             if (TreeInfo.isStaticSelector(that.expr, names)) {
  2682                 //if the qualifier is a type, validate it; raw warning check is
  2683                 //omitted as we don't know at this stage as to whether this is a
  2684                 //raw selector (because of inference)
  2685                 chk.validate(that.expr, env, false);
  2688             //attrib type-arguments
  2689             List<Type> typeargtypes = List.nil();
  2690             if (that.typeargs != null) {
  2691                 typeargtypes = attribTypes(that.typeargs, localEnv);
  2694             Type target;
  2695             Type desc;
  2696             if (pt() != Type.recoveryType) {
  2697                 target = targetChecker.visit(pt(), that);
  2698                 desc = types.findDescriptorType(target);
  2699             } else {
  2700                 target = Type.recoveryType;
  2701                 desc = fallbackDescriptorType(that);
  2704             setFunctionalInfo(localEnv, that, pt(), desc, target, resultInfo.checkContext);
  2705             List<Type> argtypes = desc.getParameterTypes();
  2706             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
  2708             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
  2709                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
  2712             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
  2713             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
  2714             try {
  2715                 refResult = rs.resolveMemberReference(that.pos(), localEnv, that, that.expr.type,
  2716                         that.name, argtypes, typeargtypes, true, referenceCheck,
  2717                         resultInfo.checkContext.inferenceContext());
  2718             } finally {
  2719                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
  2722             Symbol refSym = refResult.fst;
  2723             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
  2725             if (refSym.kind != MTH) {
  2726                 boolean targetError;
  2727                 switch (refSym.kind) {
  2728                     case ABSENT_MTH:
  2729                         targetError = false;
  2730                         break;
  2731                     case WRONG_MTH:
  2732                     case WRONG_MTHS:
  2733                     case AMBIGUOUS:
  2734                     case HIDDEN:
  2735                     case STATICERR:
  2736                     case MISSING_ENCL:
  2737                         targetError = true;
  2738                         break;
  2739                     default:
  2740                         Assert.error("unexpected result kind " + refSym.kind);
  2741                         targetError = false;
  2744                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym).getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
  2745                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
  2747                 JCDiagnostic.DiagnosticType diagKind = targetError ?
  2748                         JCDiagnostic.DiagnosticType.FRAGMENT : JCDiagnostic.DiagnosticType.ERROR;
  2750                 JCDiagnostic diag = diags.create(diagKind, log.currentSource(), that,
  2751                         "invalid.mref", Kinds.kindName(that.getMode()), detailsDiag);
  2753                 if (targetError && target == Type.recoveryType) {
  2754                     //a target error doesn't make sense during recovery stage
  2755                     //as we don't know what actual parameter types are
  2756                     result = that.type = target;
  2757                     return;
  2758                 } else {
  2759                     if (targetError) {
  2760                         resultInfo.checkContext.report(that, diag);
  2761                     } else {
  2762                         log.report(diag);
  2764                     result = that.type = types.createErrorType(target);
  2765                     return;
  2769             that.sym = refSym.baseSymbol();
  2770             that.kind = lookupHelper.referenceKind(that.sym);
  2771             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
  2773             if (desc.getReturnType() == Type.recoveryType) {
  2774                 // stop here
  2775                 result = that.type = target;
  2776                 return;
  2779             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
  2781                 if (that.getMode() == ReferenceMode.INVOKE &&
  2782                         TreeInfo.isStaticSelector(that.expr, names) &&
  2783                         that.kind.isUnbound() &&
  2784                         !desc.getParameterTypes().head.isParameterized()) {
  2785                     chk.checkRaw(that.expr, localEnv);
  2788                 if (!that.kind.isUnbound() &&
  2789                         that.getMode() == ReferenceMode.INVOKE &&
  2790                         TreeInfo.isStaticSelector(that.expr, names) &&
  2791                         !that.sym.isStatic()) {
  2792                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2793                             diags.fragment("non-static.cant.be.ref", Kinds.kindName(refSym), refSym));
  2794                     result = that.type = types.createErrorType(target);
  2795                     return;
  2798                 if (that.kind.isUnbound() &&
  2799                         that.getMode() == ReferenceMode.INVOKE &&
  2800                         TreeInfo.isStaticSelector(that.expr, names) &&
  2801                         that.sym.isStatic()) {
  2802                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2803                             diags.fragment("static.method.in.unbound.lookup", Kinds.kindName(refSym), refSym));
  2804                     result = that.type = types.createErrorType(target);
  2805                     return;
  2808                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
  2809                         exprType.getTypeArguments().nonEmpty()) {
  2810                     //static ref with class type-args
  2811                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2812                             diags.fragment("static.mref.with.targs"));
  2813                     result = that.type = types.createErrorType(target);
  2814                     return;
  2817                 if (that.sym.isStatic() && !TreeInfo.isStaticSelector(that.expr, names) &&
  2818                         !that.kind.isUnbound()) {
  2819                     //no static bound mrefs
  2820                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2821                             diags.fragment("static.bound.mref"));
  2822                     result = that.type = types.createErrorType(target);
  2823                     return;
  2826                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
  2827                     // Check that super-qualified symbols are not abstract (JLS)
  2828                     rs.checkNonAbstract(that.pos(), that.sym);
  2832             ResultInfo checkInfo =
  2833                     resultInfo.dup(newMethodTemplate(
  2834                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
  2835                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes));
  2837             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
  2839             if (that.kind.isUnbound() &&
  2840                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
  2841                 //re-generate inference constraints for unbound receiver
  2842                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asFree(argtypes.head), exprType)) {
  2843                     //cannot happen as this has already been checked - we just need
  2844                     //to regenerate the inference constraints, as that has been lost
  2845                     //as a result of the call to inferenceContext.save()
  2846                     Assert.error("Can't get here");
  2850             if (!refType.isErroneous()) {
  2851                 refType = types.createMethodTypeWithReturn(refType,
  2852                         adjustMethodReturnType(lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
  2855             //go ahead with standard method reference compatibility check - note that param check
  2856             //is a no-op (as this has been taken care during method applicability)
  2857             boolean isSpeculativeRound =
  2858                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
  2859             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
  2860             if (!isSpeculativeRound) {
  2861                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, target);
  2863             result = check(that, target, VAL, resultInfo);
  2864         } catch (Types.FunctionDescriptorLookupError ex) {
  2865             JCDiagnostic cause = ex.getDiagnostic();
  2866             resultInfo.checkContext.report(that, cause);
  2867             result = that.type = types.createErrorType(pt());
  2868             return;
  2871     //where
  2872         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
  2873             //if this is a constructor reference, the expected kind must be a type
  2874             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ? VAL | TYP : TYP, Type.noType);
  2878     @SuppressWarnings("fallthrough")
  2879     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
  2880         Type returnType = checkContext.inferenceContext().asFree(descriptor.getReturnType());
  2882         Type resType;
  2883         switch (tree.getMode()) {
  2884             case NEW:
  2885                 if (!tree.expr.type.isRaw()) {
  2886                     resType = tree.expr.type;
  2887                     break;
  2889             default:
  2890                 resType = refType.getReturnType();
  2893         Type incompatibleReturnType = resType;
  2895         if (returnType.hasTag(VOID)) {
  2896             incompatibleReturnType = null;
  2899         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
  2900             if (resType.isErroneous() ||
  2901                     new FunctionalReturnContext(checkContext).compatible(resType, returnType, types.noWarnings)) {
  2902                 incompatibleReturnType = null;
  2906         if (incompatibleReturnType != null) {
  2907             checkContext.report(tree, diags.fragment("incompatible.ret.type.in.mref",
  2908                     diags.fragment("inconvertible.types", resType, descriptor.getReturnType())));
  2911         if (!speculativeAttr) {
  2912             List<Type> thrownTypes = checkContext.inferenceContext().asFree(descriptor.getThrownTypes());
  2913             if (chk.unhandled(refType.getThrownTypes(), thrownTypes).nonEmpty()) {
  2914                 log.error(tree, "incompatible.thrown.types.in.mref", refType.getThrownTypes());
  2919     /**
  2920      * Set functional type info on the underlying AST. Note: as the target descriptor
  2921      * might contain inference variables, we might need to register an hook in the
  2922      * current inference context.
  2923      */
  2924     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
  2925             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
  2926         if (checkContext.inferenceContext().free(descriptorType)) {
  2927             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType), new FreeTypeListener() {
  2928                 public void typesInferred(InferenceContext inferenceContext) {
  2929                     setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
  2930                             inferenceContext.asInstType(primaryTarget), checkContext);
  2932             });
  2933         } else {
  2934             ListBuffer<Type> targets = ListBuffer.lb();
  2935             if (pt.hasTag(CLASS)) {
  2936                 if (pt.isCompound()) {
  2937                     targets.append(types.removeWildcards(primaryTarget)); //this goes first
  2938                     for (Type t : ((IntersectionClassType)pt()).interfaces_field) {
  2939                         if (t != primaryTarget) {
  2940                             targets.append(types.removeWildcards(t));
  2943                 } else {
  2944                     targets.append(types.removeWildcards(primaryTarget));
  2947             fExpr.targets = targets.toList();
  2948             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
  2949                     pt != Type.recoveryType) {
  2950                 //check that functional interface class is well-formed
  2951                 ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
  2952                         names.empty, List.of(fExpr.targets.head), ABSTRACT);
  2953                 if (csym != null) {
  2954                     chk.checkImplementations(env.tree, csym, csym);
  2960     public void visitParens(JCParens tree) {
  2961         Type owntype = attribTree(tree.expr, env, resultInfo);
  2962         result = check(tree, owntype, pkind(), resultInfo);
  2963         Symbol sym = TreeInfo.symbol(tree);
  2964         if (sym != null && (sym.kind&(TYP|PCK)) != 0)
  2965             log.error(tree.pos(), "illegal.start.of.type");
  2968     public void visitAssign(JCAssign tree) {
  2969         Type owntype = attribTree(tree.lhs, env.dup(tree), varInfo);
  2970         Type capturedType = capture(owntype);
  2971         attribExpr(tree.rhs, env, owntype);
  2972         result = check(tree, capturedType, VAL, resultInfo);
  2975     public void visitAssignop(JCAssignOp tree) {
  2976         // Attribute arguments.
  2977         Type owntype = attribTree(tree.lhs, env, varInfo);
  2978         Type operand = attribExpr(tree.rhs, env);
  2979         // Find operator.
  2980         Symbol operator = tree.operator = rs.resolveBinaryOperator(
  2981             tree.pos(), tree.getTag().noAssignOp(), env,
  2982             owntype, operand);
  2984         if (operator.kind == MTH &&
  2985                 !owntype.isErroneous() &&
  2986                 !operand.isErroneous()) {
  2987             chk.checkOperator(tree.pos(),
  2988                               (OperatorSymbol)operator,
  2989                               tree.getTag().noAssignOp(),
  2990                               owntype,
  2991                               operand);
  2992             chk.checkDivZero(tree.rhs.pos(), operator, operand);
  2993             chk.checkCastable(tree.rhs.pos(),
  2994                               operator.type.getReturnType(),
  2995                               owntype);
  2997         result = check(tree, owntype, VAL, resultInfo);
  3000     public void visitUnary(JCUnary tree) {
  3001         // Attribute arguments.
  3002         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
  3003             ? attribTree(tree.arg, env, varInfo)
  3004             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
  3006         // Find operator.
  3007         Symbol operator = tree.operator =
  3008             rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
  3010         Type owntype = types.createErrorType(tree.type);
  3011         if (operator.kind == MTH &&
  3012                 !argtype.isErroneous()) {
  3013             owntype = (tree.getTag().isIncOrDecUnaryOp())
  3014                 ? tree.arg.type
  3015                 : operator.type.getReturnType();
  3016             int opc = ((OperatorSymbol)operator).opcode;
  3018             // If the argument is constant, fold it.
  3019             if (argtype.constValue() != null) {
  3020                 Type ctype = cfolder.fold1(opc, argtype);
  3021                 if (ctype != null) {
  3022                     owntype = cfolder.coerce(ctype, owntype);
  3024                     // Remove constant types from arguments to
  3025                     // conserve space. The parser will fold concatenations
  3026                     // of string literals; the code here also
  3027                     // gets rid of intermediate results when some of the
  3028                     // operands are constant identifiers.
  3029                     if (tree.arg.type.tsym == syms.stringType.tsym) {
  3030                         tree.arg.type = syms.stringType;
  3035         result = check(tree, owntype, VAL, resultInfo);
  3038     public void visitBinary(JCBinary tree) {
  3039         // Attribute arguments.
  3040         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
  3041         Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
  3043         // Find operator.
  3044         Symbol operator = tree.operator =
  3045             rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
  3047         Type owntype = types.createErrorType(tree.type);
  3048         if (operator.kind == MTH &&
  3049                 !left.isErroneous() &&
  3050                 !right.isErroneous()) {
  3051             owntype = operator.type.getReturnType();
  3052             // This will figure out when unboxing can happen and
  3053             // choose the right comparison operator.
  3054             int opc = chk.checkOperator(tree.lhs.pos(),
  3055                                         (OperatorSymbol)operator,
  3056                                         tree.getTag(),
  3057                                         left,
  3058                                         right);
  3060             // If both arguments are constants, fold them.
  3061             if (left.constValue() != null && right.constValue() != null) {
  3062                 Type ctype = cfolder.fold2(opc, left, right);
  3063                 if (ctype != null) {
  3064                     owntype = cfolder.coerce(ctype, owntype);
  3066                     // Remove constant types from arguments to
  3067                     // conserve space. The parser will fold concatenations
  3068                     // of string literals; the code here also
  3069                     // gets rid of intermediate results when some of the
  3070                     // operands are constant identifiers.
  3071                     if (tree.lhs.type.tsym == syms.stringType.tsym) {
  3072                         tree.lhs.type = syms.stringType;
  3074                     if (tree.rhs.type.tsym == syms.stringType.tsym) {
  3075                         tree.rhs.type = syms.stringType;
  3080             // Check that argument types of a reference ==, != are
  3081             // castable to each other, (JLS 15.21).  Note: unboxing
  3082             // comparisons will not have an acmp* opc at this point.
  3083             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
  3084                 if (!types.isEqualityComparable(left, right,
  3085                                                 new Warner(tree.pos()))) {
  3086                     log.error(tree.pos(), "incomparable.types", left, right);
  3090             chk.checkDivZero(tree.rhs.pos(), operator, right);
  3092         result = check(tree, owntype, VAL, resultInfo);
  3095     public void visitTypeCast(final JCTypeCast tree) {
  3096         Type clazztype = attribType(tree.clazz, env);
  3097         chk.validate(tree.clazz, env, false);
  3098         //a fresh environment is required for 292 inference to work properly ---
  3099         //see Infer.instantiatePolymorphicSignatureInstance()
  3100         Env<AttrContext> localEnv = env.dup(tree);
  3101         //should we propagate the target type?
  3102         final ResultInfo castInfo;
  3103         JCExpression expr = TreeInfo.skipParens(tree.expr);
  3104         boolean isPoly = allowPoly && (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
  3105         if (isPoly) {
  3106             //expression is a poly - we need to propagate target type info
  3107             castInfo = new ResultInfo(VAL, clazztype, new Check.NestedCheckContext(resultInfo.checkContext) {
  3108                 @Override
  3109                 public boolean compatible(Type found, Type req, Warner warn) {
  3110                     return types.isCastable(found, req, warn);
  3112             });
  3113         } else {
  3114             //standalone cast - target-type info is not propagated
  3115             castInfo = unknownExprInfo;
  3117         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
  3118         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
  3119         if (exprtype.constValue() != null)
  3120             owntype = cfolder.coerce(exprtype, owntype);
  3121         result = check(tree, capture(owntype), VAL, resultInfo);
  3122         if (!isPoly)
  3123             chk.checkRedundantCast(localEnv, tree);
  3126     public void visitTypeTest(JCInstanceOf tree) {
  3127         Type exprtype = chk.checkNullOrRefType(
  3128             tree.expr.pos(), attribExpr(tree.expr, env));
  3129         Type clazztype = chk.checkReifiableReferenceType(
  3130             tree.clazz.pos(), attribType(tree.clazz, env));
  3131         chk.validate(tree.clazz, env, false);
  3132         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
  3133         result = check(tree, syms.booleanType, VAL, resultInfo);
  3136     public void visitIndexed(JCArrayAccess tree) {
  3137         Type owntype = types.createErrorType(tree.type);
  3138         Type atype = attribExpr(tree.indexed, env);
  3139         attribExpr(tree.index, env, syms.intType);
  3140         if (types.isArray(atype))
  3141             owntype = types.elemtype(atype);
  3142         else if (!atype.hasTag(ERROR))
  3143             log.error(tree.pos(), "array.req.but.found", atype);
  3144         if ((pkind() & VAR) == 0) owntype = capture(owntype);
  3145         result = check(tree, owntype, VAR, resultInfo);
  3148     public void visitIdent(JCIdent tree) {
  3149         Symbol sym;
  3151         // Find symbol
  3152         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
  3153             // If we are looking for a method, the prototype `pt' will be a
  3154             // method type with the type of the call's arguments as parameters.
  3155             env.info.pendingResolutionPhase = null;
  3156             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
  3157         } else if (tree.sym != null && tree.sym.kind != VAR) {
  3158             sym = tree.sym;
  3159         } else {
  3160             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
  3162         tree.sym = sym;
  3164         // (1) Also find the environment current for the class where
  3165         //     sym is defined (`symEnv').
  3166         // Only for pre-tiger versions (1.4 and earlier):
  3167         // (2) Also determine whether we access symbol out of an anonymous
  3168         //     class in a this or super call.  This is illegal for instance
  3169         //     members since such classes don't carry a this$n link.
  3170         //     (`noOuterThisPath').
  3171         Env<AttrContext> symEnv = env;
  3172         boolean noOuterThisPath = false;
  3173         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
  3174             (sym.kind & (VAR | MTH | TYP)) != 0 &&
  3175             sym.owner.kind == TYP &&
  3176             tree.name != names._this && tree.name != names._super) {
  3178             // Find environment in which identifier is defined.
  3179             while (symEnv.outer != null &&
  3180                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
  3181                 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
  3182                     noOuterThisPath = !allowAnonOuterThis;
  3183                 symEnv = symEnv.outer;
  3187         // If symbol is a variable, ...
  3188         if (sym.kind == VAR) {
  3189             VarSymbol v = (VarSymbol)sym;
  3191             // ..., evaluate its initializer, if it has one, and check for
  3192             // illegal forward reference.
  3193             checkInit(tree, env, v, false);
  3195             // If we are expecting a variable (as opposed to a value), check
  3196             // that the variable is assignable in the current environment.
  3197             if (pkind() == VAR)
  3198                 checkAssignable(tree.pos(), v, null, env);
  3201         // In a constructor body,
  3202         // if symbol is a field or instance method, check that it is
  3203         // not accessed before the supertype constructor is called.
  3204         if ((symEnv.info.isSelfCall || noOuterThisPath) &&
  3205             (sym.kind & (VAR | MTH)) != 0 &&
  3206             sym.owner.kind == TYP &&
  3207             (sym.flags() & STATIC) == 0) {
  3208             chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
  3210         Env<AttrContext> env1 = env;
  3211         if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
  3212             // If the found symbol is inaccessible, then it is
  3213             // accessed through an enclosing instance.  Locate this
  3214             // enclosing instance:
  3215             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
  3216                 env1 = env1.outer;
  3218         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
  3221     public void visitSelect(JCFieldAccess tree) {
  3222         // Determine the expected kind of the qualifier expression.
  3223         int skind = 0;
  3224         if (tree.name == names._this || tree.name == names._super ||
  3225             tree.name == names._class)
  3227             skind = TYP;
  3228         } else {
  3229             if ((pkind() & PCK) != 0) skind = skind | PCK;
  3230             if ((pkind() & TYP) != 0) skind = skind | TYP | PCK;
  3231             if ((pkind() & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
  3234         // Attribute the qualifier expression, and determine its symbol (if any).
  3235         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Infer.anyPoly));
  3236         if ((pkind() & (PCK | TYP)) == 0)
  3237             site = capture(site); // Capture field access
  3239         // don't allow T.class T[].class, etc
  3240         if (skind == TYP) {
  3241             Type elt = site;
  3242             while (elt.hasTag(ARRAY))
  3243                 elt = ((ArrayType)elt.unannotatedType()).elemtype;
  3244             if (elt.hasTag(TYPEVAR)) {
  3245                 log.error(tree.pos(), "type.var.cant.be.deref");
  3246                 result = types.createErrorType(tree.type);
  3247                 return;
  3251         // If qualifier symbol is a type or `super', assert `selectSuper'
  3252         // for the selection. This is relevant for determining whether
  3253         // protected symbols are accessible.
  3254         Symbol sitesym = TreeInfo.symbol(tree.selected);
  3255         boolean selectSuperPrev = env.info.selectSuper;
  3256         env.info.selectSuper =
  3257             sitesym != null &&
  3258             sitesym.name == names._super;
  3260         // Determine the symbol represented by the selection.
  3261         env.info.pendingResolutionPhase = null;
  3262         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
  3263         if (sym.exists() && !isType(sym) && (pkind() & (PCK | TYP)) != 0) {
  3264             site = capture(site);
  3265             sym = selectSym(tree, sitesym, site, env, resultInfo);
  3267         boolean varArgs = env.info.lastResolveVarargs();
  3268         tree.sym = sym;
  3270         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
  3271             while (site.hasTag(TYPEVAR)) site = site.getUpperBound();
  3272             site = capture(site);
  3275         // If that symbol is a variable, ...
  3276         if (sym.kind == VAR) {
  3277             VarSymbol v = (VarSymbol)sym;
  3279             // ..., evaluate its initializer, if it has one, and check for
  3280             // illegal forward reference.
  3281             checkInit(tree, env, v, true);
  3283             // If we are expecting a variable (as opposed to a value), check
  3284             // that the variable is assignable in the current environment.
  3285             if (pkind() == VAR)
  3286                 checkAssignable(tree.pos(), v, tree.selected, env);
  3289         if (sitesym != null &&
  3290                 sitesym.kind == VAR &&
  3291                 ((VarSymbol)sitesym).isResourceVariable() &&
  3292                 sym.kind == MTH &&
  3293                 sym.name.equals(names.close) &&
  3294                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
  3295                 env.info.lint.isEnabled(LintCategory.TRY)) {
  3296             log.warning(LintCategory.TRY, tree, "try.explicit.close.call");
  3299         // Disallow selecting a type from an expression
  3300         if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
  3301             tree.type = check(tree.selected, pt(),
  3302                               sitesym == null ? VAL : sitesym.kind, new ResultInfo(TYP|PCK, pt()));
  3305         if (isType(sitesym)) {
  3306             if (sym.name == names._this) {
  3307                 // If `C' is the currently compiled class, check that
  3308                 // C.this' does not appear in a call to a super(...)
  3309                 if (env.info.isSelfCall &&
  3310                     site.tsym == env.enclClass.sym) {
  3311                     chk.earlyRefError(tree.pos(), sym);
  3313             } else {
  3314                 // Check if type-qualified fields or methods are static (JLS)
  3315                 if ((sym.flags() & STATIC) == 0 &&
  3316                     !env.next.tree.hasTag(REFERENCE) &&
  3317                     sym.name != names._super &&
  3318                     (sym.kind == VAR || sym.kind == MTH)) {
  3319                     rs.accessBase(rs.new StaticError(sym),
  3320                               tree.pos(), site, sym.name, true);
  3323         } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
  3324             // If the qualified item is not a type and the selected item is static, report
  3325             // a warning. Make allowance for the class of an array type e.g. Object[].class)
  3326             chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
  3329         // If we are selecting an instance member via a `super', ...
  3330         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
  3332             // Check that super-qualified symbols are not abstract (JLS)
  3333             rs.checkNonAbstract(tree.pos(), sym);
  3335             if (site.isRaw()) {
  3336                 // Determine argument types for site.
  3337                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
  3338                 if (site1 != null) site = site1;
  3342         env.info.selectSuper = selectSuperPrev;
  3343         result = checkId(tree, site, sym, env, resultInfo);
  3345     //where
  3346         /** Determine symbol referenced by a Select expression,
  3348          *  @param tree   The select tree.
  3349          *  @param site   The type of the selected expression,
  3350          *  @param env    The current environment.
  3351          *  @param resultInfo The current result.
  3352          */
  3353         private Symbol selectSym(JCFieldAccess tree,
  3354                                  Symbol location,
  3355                                  Type site,
  3356                                  Env<AttrContext> env,
  3357                                  ResultInfo resultInfo) {
  3358             DiagnosticPosition pos = tree.pos();
  3359             Name name = tree.name;
  3360             switch (site.getTag()) {
  3361             case PACKAGE:
  3362                 return rs.accessBase(
  3363                     rs.findIdentInPackage(env, site.tsym, name, resultInfo.pkind),
  3364                     pos, location, site, name, true);
  3365             case ARRAY:
  3366             case CLASS:
  3367                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
  3368                     return rs.resolveQualifiedMethod(
  3369                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
  3370                 } else if (name == names._this || name == names._super) {
  3371                     return rs.resolveSelf(pos, env, site.tsym, name);
  3372                 } else if (name == names._class) {
  3373                     // In this case, we have already made sure in
  3374                     // visitSelect that qualifier expression is a type.
  3375                     Type t = syms.classType;
  3376                     List<Type> typeargs = allowGenerics
  3377                         ? List.of(types.erasure(site))
  3378                         : List.<Type>nil();
  3379                     t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
  3380                     return new VarSymbol(
  3381                         STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
  3382                 } else {
  3383                     // We are seeing a plain identifier as selector.
  3384                     Symbol sym = rs.findIdentInType(env, site, name, resultInfo.pkind);
  3385                     if ((resultInfo.pkind & ERRONEOUS) == 0)
  3386                         sym = rs.accessBase(sym, pos, location, site, name, true);
  3387                     return sym;
  3389             case WILDCARD:
  3390                 throw new AssertionError(tree);
  3391             case TYPEVAR:
  3392                 // Normally, site.getUpperBound() shouldn't be null.
  3393                 // It should only happen during memberEnter/attribBase
  3394                 // when determining the super type which *must* beac
  3395                 // done before attributing the type variables.  In
  3396                 // other words, we are seeing this illegal program:
  3397                 // class B<T> extends A<T.foo> {}
  3398                 Symbol sym = (site.getUpperBound() != null)
  3399                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
  3400                     : null;
  3401                 if (sym == null) {
  3402                     log.error(pos, "type.var.cant.be.deref");
  3403                     return syms.errSymbol;
  3404                 } else {
  3405                     Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
  3406                         rs.new AccessError(env, site, sym) :
  3407                                 sym;
  3408                     rs.accessBase(sym2, pos, location, site, name, true);
  3409                     return sym;
  3411             case ERROR:
  3412                 // preserve identifier names through errors
  3413                 return types.createErrorType(name, site.tsym, site).tsym;
  3414             default:
  3415                 // The qualifier expression is of a primitive type -- only
  3416                 // .class is allowed for these.
  3417                 if (name == names._class) {
  3418                     // In this case, we have already made sure in Select that
  3419                     // qualifier expression is a type.
  3420                     Type t = syms.classType;
  3421                     Type arg = types.boxedClass(site).type;
  3422                     t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
  3423                     return new VarSymbol(
  3424                         STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
  3425                 } else {
  3426                     log.error(pos, "cant.deref", site);
  3427                     return syms.errSymbol;
  3432         /** Determine type of identifier or select expression and check that
  3433          *  (1) the referenced symbol is not deprecated
  3434          *  (2) the symbol's type is safe (@see checkSafe)
  3435          *  (3) if symbol is a variable, check that its type and kind are
  3436          *      compatible with the prototype and protokind.
  3437          *  (4) if symbol is an instance field of a raw type,
  3438          *      which is being assigned to, issue an unchecked warning if its
  3439          *      type changes under erasure.
  3440          *  (5) if symbol is an instance method of a raw type, issue an
  3441          *      unchecked warning if its argument types change under erasure.
  3442          *  If checks succeed:
  3443          *    If symbol is a constant, return its constant type
  3444          *    else if symbol is a method, return its result type
  3445          *    otherwise return its type.
  3446          *  Otherwise return errType.
  3448          *  @param tree       The syntax tree representing the identifier
  3449          *  @param site       If this is a select, the type of the selected
  3450          *                    expression, otherwise the type of the current class.
  3451          *  @param sym        The symbol representing the identifier.
  3452          *  @param env        The current environment.
  3453          *  @param resultInfo    The expected result
  3454          */
  3455         Type checkId(JCTree tree,
  3456                      Type site,
  3457                      Symbol sym,
  3458                      Env<AttrContext> env,
  3459                      ResultInfo resultInfo) {
  3460             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
  3461                     checkMethodId(tree, site, sym, env, resultInfo) :
  3462                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
  3465         Type checkMethodId(JCTree tree,
  3466                      Type site,
  3467                      Symbol sym,
  3468                      Env<AttrContext> env,
  3469                      ResultInfo resultInfo) {
  3470             boolean isPolymorhicSignature =
  3471                 (sym.baseSymbol().flags() & SIGNATURE_POLYMORPHIC) != 0;
  3472             return isPolymorhicSignature ?
  3473                     checkSigPolyMethodId(tree, site, sym, env, resultInfo) :
  3474                     checkMethodIdInternal(tree, site, sym, env, resultInfo);
  3477         Type checkSigPolyMethodId(JCTree tree,
  3478                      Type site,
  3479                      Symbol sym,
  3480                      Env<AttrContext> env,
  3481                      ResultInfo resultInfo) {
  3482             //recover original symbol for signature polymorphic methods
  3483             checkMethodIdInternal(tree, site, sym.baseSymbol(), env, resultInfo);
  3484             env.info.pendingResolutionPhase = Resolve.MethodResolutionPhase.BASIC;
  3485             return sym.type;
  3488         Type checkMethodIdInternal(JCTree tree,
  3489                      Type site,
  3490                      Symbol sym,
  3491                      Env<AttrContext> env,
  3492                      ResultInfo resultInfo) {
  3493             if ((resultInfo.pkind & POLY) != 0) {
  3494                 Type pt = resultInfo.pt.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, sym, env.info.pendingResolutionPhase));
  3495                 Type owntype = checkIdInternal(tree, site, sym, pt, env, resultInfo);
  3496                 resultInfo.pt.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
  3497                 return owntype;
  3498             } else {
  3499                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
  3503         Type checkIdInternal(JCTree tree,
  3504                      Type site,
  3505                      Symbol sym,
  3506                      Type pt,
  3507                      Env<AttrContext> env,
  3508                      ResultInfo resultInfo) {
  3509             if (pt.isErroneous()) {
  3510                 return types.createErrorType(site);
  3512             Type owntype; // The computed type of this identifier occurrence.
  3513             switch (sym.kind) {
  3514             case TYP:
  3515                 // For types, the computed type equals the symbol's type,
  3516                 // except for two situations:
  3517                 owntype = sym.type;
  3518                 if (owntype.hasTag(CLASS)) {
  3519                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
  3520                     Type ownOuter = owntype.getEnclosingType();
  3522                     // (a) If the symbol's type is parameterized, erase it
  3523                     // because no type parameters were given.
  3524                     // We recover generic outer type later in visitTypeApply.
  3525                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
  3526                         owntype = types.erasure(owntype);
  3529                     // (b) If the symbol's type is an inner class, then
  3530                     // we have to interpret its outer type as a superclass
  3531                     // of the site type. Example:
  3532                     //
  3533                     // class Tree<A> { class Visitor { ... } }
  3534                     // class PointTree extends Tree<Point> { ... }
  3535                     // ...PointTree.Visitor...
  3536                     //
  3537                     // Then the type of the last expression above is
  3538                     // Tree<Point>.Visitor.
  3539                     else if (ownOuter.hasTag(CLASS) && site != ownOuter) {
  3540                         Type normOuter = site;
  3541                         if (normOuter.hasTag(CLASS)) {
  3542                             normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
  3543                             if (site.isAnnotated()) {
  3544                                 // Propagate any type annotations.
  3545                                 // TODO: should asEnclosingSuper do this?
  3546                                 // Note that the type annotations in site will be updated
  3547                                 // by annotateType. Therefore, modify site instead
  3548                                 // of creating a new AnnotatedType.
  3549                                 ((AnnotatedType)site).underlyingType = normOuter;
  3550                                 normOuter = site;
  3553                         if (normOuter == null) // perhaps from an import
  3554                             normOuter = types.erasure(ownOuter);
  3555                         if (normOuter != ownOuter)
  3556                             owntype = new ClassType(
  3557                                 normOuter, List.<Type>nil(), owntype.tsym);
  3560                 break;
  3561             case VAR:
  3562                 VarSymbol v = (VarSymbol)sym;
  3563                 // Test (4): if symbol is an instance field of a raw type,
  3564                 // which is being assigned to, issue an unchecked warning if
  3565                 // its type changes under erasure.
  3566                 if (allowGenerics &&
  3567                     resultInfo.pkind == VAR &&
  3568                     v.owner.kind == TYP &&
  3569                     (v.flags() & STATIC) == 0 &&
  3570                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
  3571                     Type s = types.asOuterSuper(site, v.owner);
  3572                     if (s != null &&
  3573                         s.isRaw() &&
  3574                         !types.isSameType(v.type, v.erasure(types))) {
  3575                         chk.warnUnchecked(tree.pos(),
  3576                                           "unchecked.assign.to.var",
  3577                                           v, s);
  3580                 // The computed type of a variable is the type of the
  3581                 // variable symbol, taken as a member of the site type.
  3582                 owntype = (sym.owner.kind == TYP &&
  3583                            sym.name != names._this && sym.name != names._super)
  3584                     ? types.memberType(site, sym)
  3585                     : sym.type;
  3587                 // If the variable is a constant, record constant value in
  3588                 // computed type.
  3589                 if (v.getConstValue() != null && isStaticReference(tree))
  3590                     owntype = owntype.constType(v.getConstValue());
  3592                 if (resultInfo.pkind == VAL) {
  3593                     owntype = capture(owntype); // capture "names as expressions"
  3595                 break;
  3596             case MTH: {
  3597                 owntype = checkMethod(site, sym,
  3598                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext),
  3599                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
  3600                         resultInfo.pt.getTypeArguments());
  3601                 break;
  3603             case PCK: case ERR:
  3604                 owntype = sym.type;
  3605                 break;
  3606             default:
  3607                 throw new AssertionError("unexpected kind: " + sym.kind +
  3608                                          " in tree " + tree);
  3611             // Test (1): emit a `deprecation' warning if symbol is deprecated.
  3612             // (for constructors, the error was given when the constructor was
  3613             // resolved)
  3615             if (sym.name != names.init) {
  3616                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
  3617                 chk.checkSunAPI(tree.pos(), sym);
  3618                 chk.checkProfile(tree.pos(), sym);
  3621             // Test (3): if symbol is a variable, check that its type and
  3622             // kind are compatible with the prototype and protokind.
  3623             return check(tree, owntype, sym.kind, resultInfo);
  3626         /** Check that variable is initialized and evaluate the variable's
  3627          *  initializer, if not yet done. Also check that variable is not
  3628          *  referenced before it is defined.
  3629          *  @param tree    The tree making up the variable reference.
  3630          *  @param env     The current environment.
  3631          *  @param v       The variable's symbol.
  3632          */
  3633         private void checkInit(JCTree tree,
  3634                                Env<AttrContext> env,
  3635                                VarSymbol v,
  3636                                boolean onlyWarning) {
  3637 //          System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
  3638 //                             tree.pos + " " + v.pos + " " +
  3639 //                             Resolve.isStatic(env));//DEBUG
  3641             // A forward reference is diagnosed if the declaration position
  3642             // of the variable is greater than the current tree position
  3643             // and the tree and variable definition occur in the same class
  3644             // definition.  Note that writes don't count as references.
  3645             // This check applies only to class and instance
  3646             // variables.  Local variables follow different scope rules,
  3647             // and are subject to definite assignment checking.
  3648             if ((env.info.enclVar == v || v.pos > tree.pos) &&
  3649                 v.owner.kind == TYP &&
  3650                 canOwnInitializer(owner(env)) &&
  3651                 v.owner == env.info.scope.owner.enclClass() &&
  3652                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
  3653                 (!env.tree.hasTag(ASSIGN) ||
  3654                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
  3655                 String suffix = (env.info.enclVar == v) ?
  3656                                 "self.ref" : "forward.ref";
  3657                 if (!onlyWarning || isStaticEnumField(v)) {
  3658                     log.error(tree.pos(), "illegal." + suffix);
  3659                 } else if (useBeforeDeclarationWarning) {
  3660                     log.warning(tree.pos(), suffix, v);
  3664             v.getConstValue(); // ensure initializer is evaluated
  3666             checkEnumInitializer(tree, env, v);
  3669         /**
  3670          * Check for illegal references to static members of enum.  In
  3671          * an enum type, constructors and initializers may not
  3672          * reference its static members unless they are constant.
  3674          * @param tree    The tree making up the variable reference.
  3675          * @param env     The current environment.
  3676          * @param v       The variable's symbol.
  3677          * @jls  section 8.9 Enums
  3678          */
  3679         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
  3680             // JLS:
  3681             //
  3682             // "It is a compile-time error to reference a static field
  3683             // of an enum type that is not a compile-time constant
  3684             // (15.28) from constructors, instance initializer blocks,
  3685             // or instance variable initializer expressions of that
  3686             // type. It is a compile-time error for the constructors,
  3687             // instance initializer blocks, or instance variable
  3688             // initializer expressions of an enum constant e to refer
  3689             // to itself or to an enum constant of the same type that
  3690             // is declared to the right of e."
  3691             if (isStaticEnumField(v)) {
  3692                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
  3694                 if (enclClass == null || enclClass.owner == null)
  3695                     return;
  3697                 // See if the enclosing class is the enum (or a
  3698                 // subclass thereof) declaring v.  If not, this
  3699                 // reference is OK.
  3700                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
  3701                     return;
  3703                 // If the reference isn't from an initializer, then
  3704                 // the reference is OK.
  3705                 if (!Resolve.isInitializer(env))
  3706                     return;
  3708                 log.error(tree.pos(), "illegal.enum.static.ref");
  3712         /** Is the given symbol a static, non-constant field of an Enum?
  3713          *  Note: enum literals should not be regarded as such
  3714          */
  3715         private boolean isStaticEnumField(VarSymbol v) {
  3716             return Flags.isEnum(v.owner) &&
  3717                    Flags.isStatic(v) &&
  3718                    !Flags.isConstant(v) &&
  3719                    v.name != names._class;
  3722         /** Can the given symbol be the owner of code which forms part
  3723          *  if class initialization? This is the case if the symbol is
  3724          *  a type or field, or if the symbol is the synthetic method.
  3725          *  owning a block.
  3726          */
  3727         private boolean canOwnInitializer(Symbol sym) {
  3728             return
  3729                 (sym.kind & (VAR | TYP)) != 0 ||
  3730                 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
  3733     Warner noteWarner = new Warner();
  3735     /**
  3736      * Check that method arguments conform to its instantiation.
  3737      **/
  3738     public Type checkMethod(Type site,
  3739                             Symbol sym,
  3740                             ResultInfo resultInfo,
  3741                             Env<AttrContext> env,
  3742                             final List<JCExpression> argtrees,
  3743                             List<Type> argtypes,
  3744                             List<Type> typeargtypes) {
  3745         // Test (5): if symbol is an instance method of a raw type, issue
  3746         // an unchecked warning if its argument types change under erasure.
  3747         if (allowGenerics &&
  3748             (sym.flags() & STATIC) == 0 &&
  3749             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
  3750             Type s = types.asOuterSuper(site, sym.owner);
  3751             if (s != null && s.isRaw() &&
  3752                 !types.isSameTypes(sym.type.getParameterTypes(),
  3753                                    sym.erasure(types).getParameterTypes())) {
  3754                 chk.warnUnchecked(env.tree.pos(),
  3755                                   "unchecked.call.mbr.of.raw.type",
  3756                                   sym, s);
  3760         if (env.info.defaultSuperCallSite != null) {
  3761             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
  3762                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
  3763                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
  3764                 List<MethodSymbol> icand_sup =
  3765                         types.interfaceCandidates(sup, (MethodSymbol)sym);
  3766                 if (icand_sup.nonEmpty() &&
  3767                         icand_sup.head != sym &&
  3768                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
  3769                     log.error(env.tree.pos(), "illegal.default.super.call", env.info.defaultSuperCallSite,
  3770                         diags.fragment("overridden.default", sym, sup));
  3771                     break;
  3774             env.info.defaultSuperCallSite = null;
  3777         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
  3778             JCMethodInvocation app = (JCMethodInvocation)env.tree;
  3779             if (app.meth.hasTag(SELECT) &&
  3780                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
  3781                 log.error(env.tree.pos(), "illegal.static.intf.meth.call", site);
  3785         // Compute the identifier's instantiated type.
  3786         // For methods, we need to compute the instance type by
  3787         // Resolve.instantiate from the symbol's type as well as
  3788         // any type arguments and value arguments.
  3789         noteWarner.clear();
  3790         try {
  3791             Type owntype = rs.checkMethod(
  3792                     env,
  3793                     site,
  3794                     sym,
  3795                     resultInfo,
  3796                     argtypes,
  3797                     typeargtypes,
  3798                     noteWarner);
  3800             DeferredAttr.DeferredTypeMap checkDeferredMap =
  3801                 deferredAttr.new DeferredTypeMap(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
  3803             argtypes = Type.map(argtypes, checkDeferredMap);
  3805             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
  3806                 chk.warnUnchecked(env.tree.pos(),
  3807                         "unchecked.meth.invocation.applied",
  3808                         kindName(sym),
  3809                         sym.name,
  3810                         rs.methodArguments(sym.type.getParameterTypes()),
  3811                         rs.methodArguments(Type.map(argtypes, checkDeferredMap)),
  3812                         kindName(sym.location()),
  3813                         sym.location());
  3814                owntype = new MethodType(owntype.getParameterTypes(),
  3815                        types.erasure(owntype.getReturnType()),
  3816                        types.erasure(owntype.getThrownTypes()),
  3817                        syms.methodClass);
  3820             return chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
  3821                     resultInfo.checkContext.inferenceContext());
  3822         } catch (Infer.InferenceException ex) {
  3823             //invalid target type - propagate exception outwards or report error
  3824             //depending on the current check context
  3825             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
  3826             return types.createErrorType(site);
  3827         } catch (Resolve.InapplicableMethodException ex) {
  3828             Assert.error(ex.getDiagnostic().getMessage(Locale.getDefault()));
  3829             return null;
  3833     public void visitLiteral(JCLiteral tree) {
  3834         result = check(
  3835             tree, litType(tree.typetag).constType(tree.value), VAL, resultInfo);
  3837     //where
  3838     /** Return the type of a literal with given type tag.
  3839      */
  3840     Type litType(TypeTag tag) {
  3841         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
  3844     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
  3845         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], TYP, resultInfo);
  3848     public void visitTypeArray(JCArrayTypeTree tree) {
  3849         Type etype = attribType(tree.elemtype, env);
  3850         Type type = new ArrayType(etype, syms.arrayClass);
  3851         result = check(tree, type, TYP, resultInfo);
  3854     /** Visitor method for parameterized types.
  3855      *  Bound checking is left until later, since types are attributed
  3856      *  before supertype structure is completely known
  3857      */
  3858     public void visitTypeApply(JCTypeApply tree) {
  3859         Type owntype = types.createErrorType(tree.type);
  3861         // Attribute functor part of application and make sure it's a class.
  3862         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
  3864         // Attribute type parameters
  3865         List<Type> actuals = attribTypes(tree.arguments, env);
  3867         if (clazztype.hasTag(CLASS)) {
  3868             List<Type> formals = clazztype.tsym.type.getTypeArguments();
  3869             if (actuals.isEmpty()) //diamond
  3870                 actuals = formals;
  3872             if (actuals.length() == formals.length()) {
  3873                 List<Type> a = actuals;
  3874                 List<Type> f = formals;
  3875                 while (a.nonEmpty()) {
  3876                     a.head = a.head.withTypeVar(f.head);
  3877                     a = a.tail;
  3878                     f = f.tail;
  3880                 // Compute the proper generic outer
  3881                 Type clazzOuter = clazztype.getEnclosingType();
  3882                 if (clazzOuter.hasTag(CLASS)) {
  3883                     Type site;
  3884                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
  3885                     if (clazz.hasTag(IDENT)) {
  3886                         site = env.enclClass.sym.type;
  3887                     } else if (clazz.hasTag(SELECT)) {
  3888                         site = ((JCFieldAccess) clazz).selected.type;
  3889                     } else throw new AssertionError(""+tree);
  3890                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
  3891                         if (site.hasTag(CLASS))
  3892                             site = types.asOuterSuper(site, clazzOuter.tsym);
  3893                         if (site == null)
  3894                             site = types.erasure(clazzOuter);
  3895                         clazzOuter = site;
  3898                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
  3899                 if (clazztype.isAnnotated()) {
  3900                     // Use the same AnnotatedType, because it will have
  3901                     // its annotations set later.
  3902                     ((AnnotatedType)clazztype).underlyingType = owntype;
  3903                     owntype = clazztype;
  3905             } else {
  3906                 if (formals.length() != 0) {
  3907                     log.error(tree.pos(), "wrong.number.type.args",
  3908                               Integer.toString(formals.length()));
  3909                 } else {
  3910                     log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
  3912                 owntype = types.createErrorType(tree.type);
  3915         result = check(tree, owntype, TYP, resultInfo);
  3918     public void visitTypeUnion(JCTypeUnion tree) {
  3919         ListBuffer<Type> multicatchTypes = ListBuffer.lb();
  3920         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
  3921         for (JCExpression typeTree : tree.alternatives) {
  3922             Type ctype = attribType(typeTree, env);
  3923             ctype = chk.checkType(typeTree.pos(),
  3924                           chk.checkClassType(typeTree.pos(), ctype),
  3925                           syms.throwableType);
  3926             if (!ctype.isErroneous()) {
  3927                 //check that alternatives of a union type are pairwise
  3928                 //unrelated w.r.t. subtyping
  3929                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
  3930                     for (Type t : multicatchTypes) {
  3931                         boolean sub = types.isSubtype(ctype, t);
  3932                         boolean sup = types.isSubtype(t, ctype);
  3933                         if (sub || sup) {
  3934                             //assume 'a' <: 'b'
  3935                             Type a = sub ? ctype : t;
  3936                             Type b = sub ? t : ctype;
  3937                             log.error(typeTree.pos(), "multicatch.types.must.be.disjoint", a, b);
  3941                 multicatchTypes.append(ctype);
  3942                 if (all_multicatchTypes != null)
  3943                     all_multicatchTypes.append(ctype);
  3944             } else {
  3945                 if (all_multicatchTypes == null) {
  3946                     all_multicatchTypes = ListBuffer.lb();
  3947                     all_multicatchTypes.appendList(multicatchTypes);
  3949                 all_multicatchTypes.append(ctype);
  3952         Type t = check(tree, types.lub(multicatchTypes.toList()), TYP, resultInfo);
  3953         if (t.hasTag(CLASS)) {
  3954             List<Type> alternatives =
  3955                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
  3956             t = new UnionClassType((ClassType) t, alternatives);
  3958         tree.type = result = t;
  3961     public void visitTypeIntersection(JCTypeIntersection tree) {
  3962         attribTypes(tree.bounds, env);
  3963         tree.type = result = checkIntersection(tree, tree.bounds);
  3966     public void visitTypeParameter(JCTypeParameter tree) {
  3967         TypeVar typeVar = (TypeVar) tree.type;
  3969         if (tree.annotations != null && tree.annotations.nonEmpty()) {
  3970             AnnotatedType antype = new AnnotatedType(typeVar);
  3971             annotateType(antype, tree.annotations);
  3972             tree.type = antype;
  3975         if (!typeVar.bound.isErroneous()) {
  3976             //fixup type-parameter bound computed in 'attribTypeVariables'
  3977             typeVar.bound = checkIntersection(tree, tree.bounds);
  3981     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
  3982         Set<Type> boundSet = new HashSet<Type>();
  3983         if (bounds.nonEmpty()) {
  3984             // accept class or interface or typevar as first bound.
  3985             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
  3986             boundSet.add(types.erasure(bounds.head.type));
  3987             if (bounds.head.type.isErroneous()) {
  3988                 return bounds.head.type;
  3990             else if (bounds.head.type.hasTag(TYPEVAR)) {
  3991                 // if first bound was a typevar, do not accept further bounds.
  3992                 if (bounds.tail.nonEmpty()) {
  3993                     log.error(bounds.tail.head.pos(),
  3994                               "type.var.may.not.be.followed.by.other.bounds");
  3995                     return bounds.head.type;
  3997             } else {
  3998                 // if first bound was a class or interface, accept only interfaces
  3999                 // as further bounds.
  4000                 for (JCExpression bound : bounds.tail) {
  4001                     bound.type = checkBase(bound.type, bound, env, false, true, false);
  4002                     if (bound.type.isErroneous()) {
  4003                         bounds = List.of(bound);
  4005                     else if (bound.type.hasTag(CLASS)) {
  4006                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
  4012         if (bounds.length() == 0) {
  4013             return syms.objectType;
  4014         } else if (bounds.length() == 1) {
  4015             return bounds.head.type;
  4016         } else {
  4017             Type owntype = types.makeCompoundType(TreeInfo.types(bounds));
  4018             if (tree.hasTag(TYPEINTERSECTION)) {
  4019                 ((IntersectionClassType)owntype).intersectionKind =
  4020                         IntersectionClassType.IntersectionKind.EXPLICIT;
  4022             // ... the variable's bound is a class type flagged COMPOUND
  4023             // (see comment for TypeVar.bound).
  4024             // In this case, generate a class tree that represents the
  4025             // bound class, ...
  4026             JCExpression extending;
  4027             List<JCExpression> implementing;
  4028             if (!bounds.head.type.isInterface()) {
  4029                 extending = bounds.head;
  4030                 implementing = bounds.tail;
  4031             } else {
  4032                 extending = null;
  4033                 implementing = bounds;
  4035             JCClassDecl cd = make.at(tree).ClassDef(
  4036                 make.Modifiers(PUBLIC | ABSTRACT),
  4037                 names.empty, List.<JCTypeParameter>nil(),
  4038                 extending, implementing, List.<JCTree>nil());
  4040             ClassSymbol c = (ClassSymbol)owntype.tsym;
  4041             Assert.check((c.flags() & COMPOUND) != 0);
  4042             cd.sym = c;
  4043             c.sourcefile = env.toplevel.sourcefile;
  4045             // ... and attribute the bound class
  4046             c.flags_field |= UNATTRIBUTED;
  4047             Env<AttrContext> cenv = enter.classEnv(cd, env);
  4048             enter.typeEnvs.put(c, cenv);
  4049             attribClass(c);
  4050             return owntype;
  4054     public void visitWildcard(JCWildcard tree) {
  4055         //- System.err.println("visitWildcard("+tree+");");//DEBUG
  4056         Type type = (tree.kind.kind == BoundKind.UNBOUND)
  4057             ? syms.objectType
  4058             : attribType(tree.inner, env);
  4059         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
  4060                                               tree.kind.kind,
  4061                                               syms.boundClass),
  4062                        TYP, resultInfo);
  4065     public void visitAnnotation(JCAnnotation tree) {
  4066         log.error(tree.pos(), "annotation.not.valid.for.type", pt());
  4067         result = tree.type = syms.errType;
  4070     public void visitAnnotatedType(JCAnnotatedType tree) {
  4071         Type underlyingType = attribType(tree.getUnderlyingType(), env);
  4072         this.attribAnnotationTypes(tree.annotations, env);
  4073         AnnotatedType antype = new AnnotatedType(underlyingType);
  4074         annotateType(antype, tree.annotations);
  4075         result = tree.type = antype;
  4078     /**
  4079      * Apply the annotations to the particular type.
  4080      */
  4081     public void annotateType(final AnnotatedType type, final List<JCAnnotation> annotations) {
  4082         if (annotations.isEmpty())
  4083             return;
  4084         annotate.typeAnnotation(new Annotate.Annotator() {
  4085             @Override
  4086             public String toString() {
  4087                 return "annotate " + annotations + " onto " + type;
  4089             @Override
  4090             public void enterAnnotation() {
  4091                 List<Attribute.TypeCompound> compounds = fromAnnotations(annotations);
  4092                 type.typeAnnotations = compounds;
  4094         });
  4097     private static List<Attribute.TypeCompound> fromAnnotations(List<JCAnnotation> annotations) {
  4098         if (annotations.isEmpty())
  4099             return List.nil();
  4101         ListBuffer<Attribute.TypeCompound> buf = ListBuffer.lb();
  4102         for (JCAnnotation anno : annotations) {
  4103             if (anno.attribute != null) {
  4104                 // TODO: this null-check is only needed for an obscure
  4105                 // ordering issue, where annotate.flush is called when
  4106                 // the attribute is not set yet. For an example failure
  4107                 // try the referenceinfos/NestedTypes.java test.
  4108                 // Any better solutions?
  4109                 buf.append((Attribute.TypeCompound) anno.attribute);
  4112         return buf.toList();
  4115     public void visitErroneous(JCErroneous tree) {
  4116         if (tree.errs != null)
  4117             for (JCTree err : tree.errs)
  4118                 attribTree(err, env, new ResultInfo(ERR, pt()));
  4119         result = tree.type = syms.errType;
  4122     /** Default visitor method for all other trees.
  4123      */
  4124     public void visitTree(JCTree tree) {
  4125         throw new AssertionError();
  4128     /**
  4129      * Attribute an env for either a top level tree or class declaration.
  4130      */
  4131     public void attrib(Env<AttrContext> env) {
  4132         if (env.tree.hasTag(TOPLEVEL))
  4133             attribTopLevel(env);
  4134         else
  4135             attribClass(env.tree.pos(), env.enclClass.sym);
  4138     /**
  4139      * Attribute a top level tree. These trees are encountered when the
  4140      * package declaration has annotations.
  4141      */
  4142     public void attribTopLevel(Env<AttrContext> env) {
  4143         JCCompilationUnit toplevel = env.toplevel;
  4144         try {
  4145             annotate.flush();
  4146             chk.validateAnnotations(toplevel.packageAnnotations, toplevel.packge);
  4147         } catch (CompletionFailure ex) {
  4148             chk.completionError(toplevel.pos(), ex);
  4152     /** Main method: attribute class definition associated with given class symbol.
  4153      *  reporting completion failures at the given position.
  4154      *  @param pos The source position at which completion errors are to be
  4155      *             reported.
  4156      *  @param c   The class symbol whose definition will be attributed.
  4157      */
  4158     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
  4159         try {
  4160             annotate.flush();
  4161             attribClass(c);
  4162         } catch (CompletionFailure ex) {
  4163             chk.completionError(pos, ex);
  4167     /** Attribute class definition associated with given class symbol.
  4168      *  @param c   The class symbol whose definition will be attributed.
  4169      */
  4170     void attribClass(ClassSymbol c) throws CompletionFailure {
  4171         if (c.type.hasTag(ERROR)) return;
  4173         // Check for cycles in the inheritance graph, which can arise from
  4174         // ill-formed class files.
  4175         chk.checkNonCyclic(null, c.type);
  4177         Type st = types.supertype(c.type);
  4178         if ((c.flags_field & Flags.COMPOUND) == 0) {
  4179             // First, attribute superclass.
  4180             if (st.hasTag(CLASS))
  4181                 attribClass((ClassSymbol)st.tsym);
  4183             // Next attribute owner, if it is a class.
  4184             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
  4185                 attribClass((ClassSymbol)c.owner);
  4188         // The previous operations might have attributed the current class
  4189         // if there was a cycle. So we test first whether the class is still
  4190         // UNATTRIBUTED.
  4191         if ((c.flags_field & UNATTRIBUTED) != 0) {
  4192             c.flags_field &= ~UNATTRIBUTED;
  4194             // Get environment current at the point of class definition.
  4195             Env<AttrContext> env = enter.typeEnvs.get(c);
  4197             // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
  4198             // because the annotations were not available at the time the env was created. Therefore,
  4199             // we look up the environment chain for the first enclosing environment for which the
  4200             // lint value is set. Typically, this is the parent env, but might be further if there
  4201             // are any envs created as a result of TypeParameter nodes.
  4202             Env<AttrContext> lintEnv = env;
  4203             while (lintEnv.info.lint == null)
  4204                 lintEnv = lintEnv.next;
  4206             // Having found the enclosing lint value, we can initialize the lint value for this class
  4207             env.info.lint = lintEnv.info.lint.augment(c);
  4209             Lint prevLint = chk.setLint(env.info.lint);
  4210             JavaFileObject prev = log.useSource(c.sourcefile);
  4211             ResultInfo prevReturnRes = env.info.returnResult;
  4213             try {
  4214                 env.info.returnResult = null;
  4215                 // java.lang.Enum may not be subclassed by a non-enum
  4216                 if (st.tsym == syms.enumSym &&
  4217                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
  4218                     log.error(env.tree.pos(), "enum.no.subclassing");
  4220                 // Enums may not be extended by source-level classes
  4221                 if (st.tsym != null &&
  4222                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
  4223                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
  4224                     log.error(env.tree.pos(), "enum.types.not.extensible");
  4226                 attribClassBody(env, c);
  4228                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
  4229                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
  4230             } finally {
  4231                 env.info.returnResult = prevReturnRes;
  4232                 log.useSource(prev);
  4233                 chk.setLint(prevLint);
  4239     public void visitImport(JCImport tree) {
  4240         // nothing to do
  4243     /** Finish the attribution of a class. */
  4244     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
  4245         JCClassDecl tree = (JCClassDecl)env.tree;
  4246         Assert.check(c == tree.sym);
  4248         // Validate annotations
  4249         chk.validateAnnotations(tree.mods.annotations, c);
  4251         // Validate type parameters, supertype and interfaces.
  4252         attribStats(tree.typarams, env);
  4253         if (!c.isAnonymous()) {
  4254             //already checked if anonymous
  4255             chk.validate(tree.typarams, env);
  4256             chk.validate(tree.extending, env);
  4257             chk.validate(tree.implementing, env);
  4260         // If this is a non-abstract class, check that it has no abstract
  4261         // methods or unimplemented methods of an implemented interface.
  4262         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
  4263             if (!relax)
  4264                 chk.checkAllDefined(tree.pos(), c);
  4267         if ((c.flags() & ANNOTATION) != 0) {
  4268             if (tree.implementing.nonEmpty())
  4269                 log.error(tree.implementing.head.pos(),
  4270                           "cant.extend.intf.annotation");
  4271             if (tree.typarams.nonEmpty())
  4272                 log.error(tree.typarams.head.pos(),
  4273                           "intf.annotation.cant.have.type.params");
  4275             // If this annotation has a @Repeatable, validate
  4276             Attribute.Compound repeatable = c.attribute(syms.repeatableType.tsym);
  4277             if (repeatable != null) {
  4278                 // get diagnostic position for error reporting
  4279                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
  4280                 Assert.checkNonNull(cbPos);
  4282                 chk.validateRepeatable(c, repeatable, cbPos);
  4284         } else {
  4285             // Check that all extended classes and interfaces
  4286             // are compatible (i.e. no two define methods with same arguments
  4287             // yet different return types).  (JLS 8.4.6.3)
  4288             chk.checkCompatibleSupertypes(tree.pos(), c.type);
  4289             if (allowDefaultMethods) {
  4290                 chk.checkDefaultMethodClashes(tree.pos(), c.type);
  4294         // Check that class does not import the same parameterized interface
  4295         // with two different argument lists.
  4296         chk.checkClassBounds(tree.pos(), c.type);
  4298         tree.type = c.type;
  4300         for (List<JCTypeParameter> l = tree.typarams;
  4301              l.nonEmpty(); l = l.tail) {
  4302              Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope);
  4305         // Check that a generic class doesn't extend Throwable
  4306         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
  4307             log.error(tree.extending.pos(), "generic.throwable");
  4309         // Check that all methods which implement some
  4310         // method conform to the method they implement.
  4311         chk.checkImplementations(tree);
  4313         //check that a resource implementing AutoCloseable cannot throw InterruptedException
  4314         checkAutoCloseable(tree.pos(), env, c.type);
  4316         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
  4317             // Attribute declaration
  4318             attribStat(l.head, env);
  4319             // Check that declarations in inner classes are not static (JLS 8.1.2)
  4320             // Make an exception for static constants.
  4321             if (c.owner.kind != PCK &&
  4322                 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
  4323                 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
  4324                 Symbol sym = null;
  4325                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
  4326                 if (sym == null ||
  4327                     sym.kind != VAR ||
  4328                     ((VarSymbol) sym).getConstValue() == null)
  4329                     log.error(l.head.pos(), "icls.cant.have.static.decl", c);
  4333         // Check for cycles among non-initial constructors.
  4334         chk.checkCyclicConstructors(tree);
  4336         // Check for cycles among annotation elements.
  4337         chk.checkNonCyclicElements(tree);
  4339         // Check for proper use of serialVersionUID
  4340         if (env.info.lint.isEnabled(LintCategory.SERIAL) &&
  4341             isSerializable(c) &&
  4342             (c.flags() & Flags.ENUM) == 0 &&
  4343             checkForSerial(c)) {
  4344             checkSerialVersionUID(tree, c);
  4346         if (allowTypeAnnos) {
  4347             // Correctly organize the postions of the type annotations
  4348             TypeAnnotations.organizeTypeAnnotationsBodies(this.syms, this.names, this.log, tree);
  4350             // Check type annotations applicability rules
  4351             validateTypeAnnotations(tree);
  4354         // where
  4355         boolean checkForSerial(ClassSymbol c) {
  4356             if ((c.flags() & ABSTRACT) == 0) {
  4357                 return true;
  4358             } else {
  4359                 return c.members().anyMatch(anyNonAbstractOrDefaultMethod);
  4363         public static final Filter<Symbol> anyNonAbstractOrDefaultMethod = new Filter<Symbol>() {
  4364             @Override
  4365             public boolean accepts(Symbol s) {
  4366                 return s.kind == Kinds.MTH &&
  4367                        (s.flags() & (DEFAULT | ABSTRACT)) != ABSTRACT;
  4369         };
  4371         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
  4372         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
  4373             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
  4374                 if (types.isSameType(al.head.annotationType.type, t))
  4375                     return al.head.pos();
  4378             return null;
  4381         /** check if a class is a subtype of Serializable, if that is available. */
  4382         private boolean isSerializable(ClassSymbol c) {
  4383             try {
  4384                 syms.serializableType.complete();
  4386             catch (CompletionFailure e) {
  4387                 return false;
  4389             return types.isSubtype(c.type, syms.serializableType);
  4392         /** Check that an appropriate serialVersionUID member is defined. */
  4393         private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
  4395             // check for presence of serialVersionUID
  4396             Scope.Entry e = c.members().lookup(names.serialVersionUID);
  4397             while (e.scope != null && e.sym.kind != VAR) e = e.next();
  4398             if (e.scope == null) {
  4399                 log.warning(LintCategory.SERIAL,
  4400                         tree.pos(), "missing.SVUID", c);
  4401                 return;
  4404             // check that it is static final
  4405             VarSymbol svuid = (VarSymbol)e.sym;
  4406             if ((svuid.flags() & (STATIC | FINAL)) !=
  4407                 (STATIC | FINAL))
  4408                 log.warning(LintCategory.SERIAL,
  4409                         TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
  4411             // check that it is long
  4412             else if (!svuid.type.hasTag(LONG))
  4413                 log.warning(LintCategory.SERIAL,
  4414                         TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
  4416             // check constant
  4417             else if (svuid.getConstValue() == null)
  4418                 log.warning(LintCategory.SERIAL,
  4419                         TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
  4422     private Type capture(Type type) {
  4423         return types.capture(type);
  4426     private void validateTypeAnnotations(JCTree tree) {
  4427         tree.accept(typeAnnotationsValidator);
  4429     //where
  4430     private final JCTree.Visitor typeAnnotationsValidator = new TreeScanner() {
  4432         private boolean checkAllAnnotations = false;
  4434         public void visitAnnotation(JCAnnotation tree) {
  4435             if (tree.hasTag(TYPE_ANNOTATION) || checkAllAnnotations) {
  4436                 chk.validateTypeAnnotation(tree, false);
  4438             super.visitAnnotation(tree);
  4440         public void visitTypeParameter(JCTypeParameter tree) {
  4441             chk.validateTypeAnnotations(tree.annotations, true);
  4442             scan(tree.bounds);
  4443             // Don't call super.
  4444             // This is needed because above we call validateTypeAnnotation with
  4445             // false, which would forbid annotations on type parameters.
  4446             // super.visitTypeParameter(tree);
  4448         public void visitMethodDef(JCMethodDecl tree) {
  4449             if (tree.recvparam != null &&
  4450                     tree.recvparam.vartype.type.getKind() != TypeKind.ERROR) {
  4451                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations,
  4452                         tree.recvparam.vartype.type.tsym);
  4454             if (tree.restype != null && tree.restype.type != null) {
  4455                 validateAnnotatedType(tree.restype, tree.restype.type);
  4457             super.visitMethodDef(tree);
  4459         public void visitVarDef(final JCVariableDecl tree) {
  4460             if (tree.sym != null && tree.sym.type != null)
  4461                 validateAnnotatedType(tree, tree.sym.type);
  4462             super.visitVarDef(tree);
  4464         public void visitTypeCast(JCTypeCast tree) {
  4465             if (tree.clazz != null && tree.clazz.type != null)
  4466                 validateAnnotatedType(tree.clazz, tree.clazz.type);
  4467             super.visitTypeCast(tree);
  4469         public void visitTypeTest(JCInstanceOf tree) {
  4470             if (tree.clazz != null && tree.clazz.type != null)
  4471                 validateAnnotatedType(tree.clazz, tree.clazz.type);
  4472             super.visitTypeTest(tree);
  4474         public void visitNewClass(JCNewClass tree) {
  4475             if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
  4476                 boolean prevCheck = this.checkAllAnnotations;
  4477                 try {
  4478                     this.checkAllAnnotations = true;
  4479                     scan(((JCAnnotatedType)tree.clazz).annotations);
  4480                 } finally {
  4481                     this.checkAllAnnotations = prevCheck;
  4484             super.visitNewClass(tree);
  4486         public void visitNewArray(JCNewArray tree) {
  4487             if (tree.elemtype != null && tree.elemtype.hasTag(ANNOTATED_TYPE)) {
  4488                 boolean prevCheck = this.checkAllAnnotations;
  4489                 try {
  4490                     this.checkAllAnnotations = true;
  4491                     scan(((JCAnnotatedType)tree.elemtype).annotations);
  4492                 } finally {
  4493                     this.checkAllAnnotations = prevCheck;
  4496             super.visitNewArray(tree);
  4499         /* I would want to model this after
  4500          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
  4501          * and override visitSelect and visitTypeApply.
  4502          * However, we only set the annotated type in the top-level type
  4503          * of the symbol.
  4504          * Therefore, we need to override each individual location where a type
  4505          * can occur.
  4506          */
  4507         private void validateAnnotatedType(final JCTree errtree, final Type type) {
  4508             if (type.getEnclosingType() != null &&
  4509                     type != type.getEnclosingType()) {
  4510                 validateEnclosingAnnotatedType(errtree, type.getEnclosingType());
  4512             for (Type targ : type.getTypeArguments()) {
  4513                 validateAnnotatedType(errtree, targ);
  4516         private void validateEnclosingAnnotatedType(final JCTree errtree, final Type type) {
  4517             validateAnnotatedType(errtree, type);
  4518             if (type.tsym != null &&
  4519                     type.tsym.isStatic() &&
  4520                     type.getAnnotationMirrors().nonEmpty()) {
  4521                     // Enclosing static classes cannot have type annotations.
  4522                 log.error(errtree.pos(), "cant.annotate.static.class");
  4525     };
  4527     // <editor-fold desc="post-attribution visitor">
  4529     /**
  4530      * Handle missing types/symbols in an AST. This routine is useful when
  4531      * the compiler has encountered some errors (which might have ended up
  4532      * terminating attribution abruptly); if the compiler is used in fail-over
  4533      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
  4534      * prevents NPE to be progagated during subsequent compilation steps.
  4535      */
  4536     public void postAttr(JCTree tree) {
  4537         new PostAttrAnalyzer().scan(tree);
  4540     class PostAttrAnalyzer extends TreeScanner {
  4542         private void initTypeIfNeeded(JCTree that) {
  4543             if (that.type == null) {
  4544                 that.type = syms.unknownType;
  4548         @Override
  4549         public void scan(JCTree tree) {
  4550             if (tree == null) return;
  4551             if (tree instanceof JCExpression) {
  4552                 initTypeIfNeeded(tree);
  4554             super.scan(tree);
  4557         @Override
  4558         public void visitIdent(JCIdent that) {
  4559             if (that.sym == null) {
  4560                 that.sym = syms.unknownSymbol;
  4564         @Override
  4565         public void visitSelect(JCFieldAccess that) {
  4566             if (that.sym == null) {
  4567                 that.sym = syms.unknownSymbol;
  4569             super.visitSelect(that);
  4572         @Override
  4573         public void visitClassDef(JCClassDecl that) {
  4574             initTypeIfNeeded(that);
  4575             if (that.sym == null) {
  4576                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
  4578             super.visitClassDef(that);
  4581         @Override
  4582         public void visitMethodDef(JCMethodDecl that) {
  4583             initTypeIfNeeded(that);
  4584             if (that.sym == null) {
  4585                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
  4587             super.visitMethodDef(that);
  4590         @Override
  4591         public void visitVarDef(JCVariableDecl that) {
  4592             initTypeIfNeeded(that);
  4593             if (that.sym == null) {
  4594                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
  4595                 that.sym.adr = 0;
  4597             super.visitVarDef(that);
  4600         @Override
  4601         public void visitNewClass(JCNewClass that) {
  4602             if (that.constructor == null) {
  4603                 that.constructor = new MethodSymbol(0, names.init, syms.unknownType, syms.noSymbol);
  4605             if (that.constructorType == null) {
  4606                 that.constructorType = syms.unknownType;
  4608             super.visitNewClass(that);
  4611         @Override
  4612         public void visitAssignop(JCAssignOp that) {
  4613             if (that.operator == null)
  4614                 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
  4615             super.visitAssignop(that);
  4618         @Override
  4619         public void visitBinary(JCBinary that) {
  4620             if (that.operator == null)
  4621                 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
  4622             super.visitBinary(that);
  4625         @Override
  4626         public void visitUnary(JCUnary that) {
  4627             if (that.operator == null)
  4628                 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
  4629             super.visitUnary(that);
  4632         @Override
  4633         public void visitLambda(JCLambda that) {
  4634             super.visitLambda(that);
  4635             if (that.targets == null) {
  4636                 that.targets = List.nil();
  4640         @Override
  4641         public void visitReference(JCMemberReference that) {
  4642             super.visitReference(that);
  4643             if (that.sym == null) {
  4644                 that.sym = new MethodSymbol(0, names.empty, syms.unknownType, syms.noSymbol);
  4646             if (that.targets == null) {
  4647                 that.targets = List.nil();
  4651     // </editor-fold>

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