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

Wed, 16 Jan 2013 17:40:28 +0000

author
mcimadamore
date
Wed, 16 Jan 2013 17:40:28 +0000
changeset 1498
1afdf1f1472b
parent 1492
df694c775e8a
child 1510
7873d37f5b37
permissions
-rw-r--r--

8005964: Regression: difference in error recovery after ambiguity causes JCK test failure
Summary: Wrong implementation of ResolveError.access in AmbiguityError
Reviewed-by: jjh

     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.*;
    29 import java.util.Set;
    31 import javax.lang.model.element.ElementKind;
    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.InferenceContext.FreeTypeListener;
    47 import com.sun.tools.javac.jvm.*;
    48 import com.sun.tools.javac.jvm.Target;
    49 import com.sun.tools.javac.tree.*;
    50 import com.sun.tools.javac.tree.JCTree.*;
    51 import com.sun.tools.javac.util.*;
    52 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
    53 import com.sun.tools.javac.util.List;
    54 import static com.sun.tools.javac.code.Flags.*;
    55 import static com.sun.tools.javac.code.Flags.ANNOTATION;
    56 import static com.sun.tools.javac.code.Flags.BLOCK;
    57 import static com.sun.tools.javac.code.Kinds.*;
    58 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
    59 import static com.sun.tools.javac.code.TypeTag.*;
    60 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
    61 import static com.sun.tools.javac.tree.JCTree.Tag.*;
    63 /** This is the main context-dependent analysis phase in GJC. It
    64  *  encompasses name resolution, type checking and constant folding as
    65  *  subtasks. Some subtasks involve auxiliary classes.
    66  *  @see Check
    67  *  @see Resolve
    68  *  @see ConstFold
    69  *  @see Infer
    70  *
    71  *  <p><b>This is NOT part of any supported API.
    72  *  If you write code that depends on this, you do so at your own risk.
    73  *  This code and its internal interfaces are subject to change or
    74  *  deletion without notice.</b>
    75  */
    76 public class Attr extends JCTree.Visitor {
    77     protected static final Context.Key<Attr> attrKey =
    78         new Context.Key<Attr>();
    80     final Names names;
    81     final Log log;
    82     final Symtab syms;
    83     final Resolve rs;
    84     final Infer infer;
    85     final DeferredAttr deferredAttr;
    86     final Check chk;
    87     final Flow flow;
    88     final MemberEnter memberEnter;
    89     final TreeMaker make;
    90     final ConstFold cfolder;
    91     final Enter enter;
    92     final Target target;
    93     final Types types;
    94     final JCDiagnostic.Factory diags;
    95     final Annotate annotate;
    96     final DeferredLintHandler deferredLintHandler;
    98     public static Attr instance(Context context) {
    99         Attr instance = context.get(attrKey);
   100         if (instance == null)
   101             instance = new Attr(context);
   102         return instance;
   103     }
   105     protected Attr(Context context) {
   106         context.put(attrKey, this);
   108         names = Names.instance(context);
   109         log = Log.instance(context);
   110         syms = Symtab.instance(context);
   111         rs = Resolve.instance(context);
   112         chk = Check.instance(context);
   113         flow = Flow.instance(context);
   114         memberEnter = MemberEnter.instance(context);
   115         make = TreeMaker.instance(context);
   116         enter = Enter.instance(context);
   117         infer = Infer.instance(context);
   118         deferredAttr = DeferredAttr.instance(context);
   119         cfolder = ConstFold.instance(context);
   120         target = Target.instance(context);
   121         types = Types.instance(context);
   122         diags = JCDiagnostic.Factory.instance(context);
   123         annotate = Annotate.instance(context);
   124         deferredLintHandler = DeferredLintHandler.instance(context);
   126         Options options = Options.instance(context);
   128         Source source = Source.instance(context);
   129         allowGenerics = source.allowGenerics();
   130         allowVarargs = source.allowVarargs();
   131         allowEnums = source.allowEnums();
   132         allowBoxing = source.allowBoxing();
   133         allowCovariantReturns = source.allowCovariantReturns();
   134         allowAnonOuterThis = source.allowAnonOuterThis();
   135         allowStringsInSwitch = source.allowStringsInSwitch();
   136         allowPoly = source.allowPoly();
   137         allowLambda = source.allowLambda();
   138         allowDefaultMethods = source.allowDefaultMethods();
   139         sourceName = source.name;
   140         relax = (options.isSet("-retrofit") ||
   141                  options.isSet("-relax"));
   142         findDiamonds = options.get("findDiamond") != null &&
   143                  source.allowDiamond();
   144         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
   145         identifyLambdaCandidate = options.getBoolean("identifyLambdaCandidate", false);
   147         statInfo = new ResultInfo(NIL, Type.noType);
   148         varInfo = new ResultInfo(VAR, Type.noType);
   149         unknownExprInfo = new ResultInfo(VAL, Type.noType);
   150         unknownTypeInfo = new ResultInfo(TYP, Type.noType);
   151         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
   152     }
   154     /** Switch: relax some constraints for retrofit mode.
   155      */
   156     boolean relax;
   158     /** Switch: support target-typing inference
   159      */
   160     boolean allowPoly;
   162     /** Switch: support generics?
   163      */
   164     boolean allowGenerics;
   166     /** Switch: allow variable-arity methods.
   167      */
   168     boolean allowVarargs;
   170     /** Switch: support enums?
   171      */
   172     boolean allowEnums;
   174     /** Switch: support boxing and unboxing?
   175      */
   176     boolean allowBoxing;
   178     /** Switch: support covariant result types?
   179      */
   180     boolean allowCovariantReturns;
   182     /** Switch: support lambda expressions ?
   183      */
   184     boolean allowLambda;
   186     /** Switch: support default methods ?
   187      */
   188     boolean allowDefaultMethods;
   190     /** Switch: allow references to surrounding object from anonymous
   191      * objects during constructor call?
   192      */
   193     boolean allowAnonOuterThis;
   195     /** Switch: generates a warning if diamond can be safely applied
   196      *  to a given new expression
   197      */
   198     boolean findDiamonds;
   200     /**
   201      * Internally enables/disables diamond finder feature
   202      */
   203     static final boolean allowDiamondFinder = true;
   205     /**
   206      * Switch: warn about use of variable before declaration?
   207      * RFE: 6425594
   208      */
   209     boolean useBeforeDeclarationWarning;
   211     /**
   212      * Switch: generate warnings whenever an anonymous inner class that is convertible
   213      * to a lambda expression is found
   214      */
   215     boolean identifyLambdaCandidate;
   217     /**
   218      * Switch: allow strings in switch?
   219      */
   220     boolean allowStringsInSwitch;
   222     /**
   223      * Switch: name of source level; used for error reporting.
   224      */
   225     String sourceName;
   227     /** Check kind and type of given tree against protokind and prototype.
   228      *  If check succeeds, store type in tree and return it.
   229      *  If check fails, store errType in tree and return it.
   230      *  No checks are performed if the prototype is a method type.
   231      *  It is not necessary in this case since we know that kind and type
   232      *  are correct.
   233      *
   234      *  @param tree     The tree whose kind and type is checked
   235      *  @param ownkind  The computed kind of the tree
   236      *  @param resultInfo  The expected result of the tree
   237      */
   238     Type check(final JCTree tree, final Type found, final int ownkind, final ResultInfo resultInfo) {
   239         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
   240         Type owntype = found;
   241         if (!owntype.hasTag(ERROR) && !resultInfo.pt.hasTag(METHOD) && !resultInfo.pt.hasTag(FORALL)) {
   242             if (inferenceContext.free(found)) {
   243                 inferenceContext.addFreeTypeListener(List.of(found, resultInfo.pt), new FreeTypeListener() {
   244                     @Override
   245                     public void typesInferred(InferenceContext inferenceContext) {
   246                         ResultInfo pendingResult =
   247                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt, types));
   248                         check(tree, inferenceContext.asInstType(found, types), ownkind, pendingResult);
   249                     }
   250                 });
   251                 return tree.type = resultInfo.pt;
   252             } else {
   253                 if ((ownkind & ~resultInfo.pkind) == 0) {
   254                     owntype = resultInfo.check(tree, owntype);
   255                 } else {
   256                     log.error(tree.pos(), "unexpected.type",
   257                             kindNames(resultInfo.pkind),
   258                             kindName(ownkind));
   259                     owntype = types.createErrorType(owntype);
   260                 }
   261             }
   262         }
   263         tree.type = owntype;
   264         return owntype;
   265     }
   267     /** Is given blank final variable assignable, i.e. in a scope where it
   268      *  may be assigned to even though it is final?
   269      *  @param v      The blank final variable.
   270      *  @param env    The current environment.
   271      */
   272     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
   273         Symbol owner = owner(env);
   274            // owner refers to the innermost variable, method or
   275            // initializer block declaration at this point.
   276         return
   277             v.owner == owner
   278             ||
   279             ((owner.name == names.init ||    // i.e. we are in a constructor
   280               owner.kind == VAR ||           // i.e. we are in a variable initializer
   281               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
   282              &&
   283              v.owner == owner.owner
   284              &&
   285              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
   286     }
   288     /**
   289      * Return the innermost enclosing owner symbol in a given attribution context
   290      */
   291     Symbol owner(Env<AttrContext> env) {
   292         while (true) {
   293             switch (env.tree.getTag()) {
   294                 case VARDEF:
   295                     //a field can be owner
   296                     VarSymbol vsym = ((JCVariableDecl)env.tree).sym;
   297                     if (vsym.owner.kind == TYP) {
   298                         return vsym;
   299                     }
   300                     break;
   301                 case METHODDEF:
   302                     //method def is always an owner
   303                     return ((JCMethodDecl)env.tree).sym;
   304                 case CLASSDEF:
   305                     //class def is always an owner
   306                     return ((JCClassDecl)env.tree).sym;
   307                 case LAMBDA:
   308                     //a lambda is an owner - return a fresh synthetic method symbol
   309                     return new MethodSymbol(0, names.empty, null, syms.methodClass);
   310                 case BLOCK:
   311                     //static/instance init blocks are owner
   312                     Symbol blockSym = env.info.scope.owner;
   313                     if ((blockSym.flags() & BLOCK) != 0) {
   314                         return blockSym;
   315                     }
   316                     break;
   317                 case TOPLEVEL:
   318                     //toplevel is always an owner (for pkge decls)
   319                     return env.info.scope.owner;
   320             }
   321             Assert.checkNonNull(env.next);
   322             env = env.next;
   323         }
   324     }
   326     /** Check that variable can be assigned to.
   327      *  @param pos    The current source code position.
   328      *  @param v      The assigned varaible
   329      *  @param base   If the variable is referred to in a Select, the part
   330      *                to the left of the `.', null otherwise.
   331      *  @param env    The current environment.
   332      */
   333     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
   334         if ((v.flags() & FINAL) != 0 &&
   335             ((v.flags() & HASINIT) != 0
   336              ||
   337              !((base == null ||
   338                (base.hasTag(IDENT) && TreeInfo.name(base) == names._this)) &&
   339                isAssignableAsBlankFinal(v, env)))) {
   340             if (v.isResourceVariable()) { //TWR resource
   341                 log.error(pos, "try.resource.may.not.be.assigned", v);
   342             } else {
   343                 log.error(pos, "cant.assign.val.to.final.var", v);
   344             }
   345         }
   346     }
   348     /** Does tree represent a static reference to an identifier?
   349      *  It is assumed that tree is either a SELECT or an IDENT.
   350      *  We have to weed out selects from non-type names here.
   351      *  @param tree    The candidate tree.
   352      */
   353     boolean isStaticReference(JCTree tree) {
   354         if (tree.hasTag(SELECT)) {
   355             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
   356             if (lsym == null || lsym.kind != TYP) {
   357                 return false;
   358             }
   359         }
   360         return true;
   361     }
   363     /** Is this symbol a type?
   364      */
   365     static boolean isType(Symbol sym) {
   366         return sym != null && sym.kind == TYP;
   367     }
   369     /** The current `this' symbol.
   370      *  @param env    The current environment.
   371      */
   372     Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
   373         return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
   374     }
   376     /** Attribute a parsed identifier.
   377      * @param tree Parsed identifier name
   378      * @param topLevel The toplevel to use
   379      */
   380     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
   381         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
   382         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
   383                                            syms.errSymbol.name,
   384                                            null, null, null, null);
   385         localEnv.enclClass.sym = syms.errSymbol;
   386         return tree.accept(identAttributer, localEnv);
   387     }
   388     // where
   389         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
   390         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
   391             @Override
   392             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
   393                 Symbol site = visit(node.getExpression(), env);
   394                 if (site.kind == ERR)
   395                     return site;
   396                 Name name = (Name)node.getIdentifier();
   397                 if (site.kind == PCK) {
   398                     env.toplevel.packge = (PackageSymbol)site;
   399                     return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK);
   400                 } else {
   401                     env.enclClass.sym = (ClassSymbol)site;
   402                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
   403                 }
   404             }
   406             @Override
   407             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
   408                 return rs.findIdent(env, (Name)node.getName(), TYP | PCK);
   409             }
   410         }
   412     public Type coerce(Type etype, Type ttype) {
   413         return cfolder.coerce(etype, ttype);
   414     }
   416     public Type attribType(JCTree node, TypeSymbol sym) {
   417         Env<AttrContext> env = enter.typeEnvs.get(sym);
   418         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
   419         return attribTree(node, localEnv, unknownTypeInfo);
   420     }
   422     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
   423         // Attribute qualifying package or class.
   424         JCFieldAccess s = (JCFieldAccess)tree.qualid;
   425         return attribTree(s.selected,
   426                        env,
   427                        new ResultInfo(tree.staticImport ? TYP : (TYP | PCK),
   428                        Type.noType));
   429     }
   431     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
   432         breakTree = tree;
   433         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
   434         try {
   435             attribExpr(expr, env);
   436         } catch (BreakAttr b) {
   437             return b.env;
   438         } catch (AssertionError ae) {
   439             if (ae.getCause() instanceof BreakAttr) {
   440                 return ((BreakAttr)(ae.getCause())).env;
   441             } else {
   442                 throw ae;
   443             }
   444         } finally {
   445             breakTree = null;
   446             log.useSource(prev);
   447         }
   448         return env;
   449     }
   451     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
   452         breakTree = tree;
   453         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
   454         try {
   455             attribStat(stmt, env);
   456         } catch (BreakAttr b) {
   457             return b.env;
   458         } catch (AssertionError ae) {
   459             if (ae.getCause() instanceof BreakAttr) {
   460                 return ((BreakAttr)(ae.getCause())).env;
   461             } else {
   462                 throw ae;
   463             }
   464         } finally {
   465             breakTree = null;
   466             log.useSource(prev);
   467         }
   468         return env;
   469     }
   471     private JCTree breakTree = null;
   473     private static class BreakAttr extends RuntimeException {
   474         static final long serialVersionUID = -6924771130405446405L;
   475         private Env<AttrContext> env;
   476         private BreakAttr(Env<AttrContext> env) {
   477             this.env = copyEnv(env);
   478         }
   480         private Env<AttrContext> copyEnv(Env<AttrContext> env) {
   481             Env<AttrContext> newEnv =
   482                     env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
   483             if (newEnv.outer != null) {
   484                 newEnv.outer = copyEnv(newEnv.outer);
   485             }
   486             return newEnv;
   487         }
   489         private Scope copyScope(Scope sc) {
   490             Scope newScope = new Scope(sc.owner);
   491             List<Symbol> elemsList = List.nil();
   492             while (sc != null) {
   493                 for (Scope.Entry e = sc.elems ; e != null ; e = e.sibling) {
   494                     elemsList = elemsList.prepend(e.sym);
   495                 }
   496                 sc = sc.next;
   497             }
   498             for (Symbol s : elemsList) {
   499                 newScope.enter(s);
   500             }
   501             return newScope;
   502         }
   503     }
   505     class ResultInfo {
   506         final int pkind;
   507         final Type pt;
   508         final CheckContext checkContext;
   510         ResultInfo(int pkind, Type pt) {
   511             this(pkind, pt, chk.basicHandler);
   512         }
   514         protected ResultInfo(int pkind, Type pt, CheckContext checkContext) {
   515             this.pkind = pkind;
   516             this.pt = pt;
   517             this.checkContext = checkContext;
   518         }
   520         protected Type check(final DiagnosticPosition pos, final Type found) {
   521             return chk.checkType(pos, found, pt, checkContext);
   522         }
   524         protected ResultInfo dup(Type newPt) {
   525             return new ResultInfo(pkind, newPt, checkContext);
   526         }
   528         protected ResultInfo dup(CheckContext newContext) {
   529             return new ResultInfo(pkind, pt, newContext);
   530         }
   531     }
   533     class RecoveryInfo extends ResultInfo {
   535         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
   536             super(Kinds.VAL, Type.recoveryType, new Check.NestedCheckContext(chk.basicHandler) {
   537                 @Override
   538                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
   539                     return deferredAttrContext;
   540                 }
   541                 @Override
   542                 public boolean compatible(Type found, Type req, Warner warn) {
   543                     return true;
   544                 }
   545                 @Override
   546                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
   547                     chk.basicHandler.report(pos, details);
   548                 }
   549             });
   550         }
   552         @Override
   553         protected Type check(DiagnosticPosition pos, Type found) {
   554             return chk.checkNonVoid(pos, super.check(pos, found));
   555         }
   556     }
   558     final ResultInfo statInfo;
   559     final ResultInfo varInfo;
   560     final ResultInfo unknownExprInfo;
   561     final ResultInfo unknownTypeInfo;
   562     final ResultInfo recoveryInfo;
   564     Type pt() {
   565         return resultInfo.pt;
   566     }
   568     int pkind() {
   569         return resultInfo.pkind;
   570     }
   572 /* ************************************************************************
   573  * Visitor methods
   574  *************************************************************************/
   576     /** Visitor argument: the current environment.
   577      */
   578     Env<AttrContext> env;
   580     /** Visitor argument: the currently expected attribution result.
   581      */
   582     ResultInfo resultInfo;
   584     /** Visitor result: the computed type.
   585      */
   586     Type result;
   588     /** Visitor method: attribute a tree, catching any completion failure
   589      *  exceptions. Return the tree's type.
   590      *
   591      *  @param tree    The tree to be visited.
   592      *  @param env     The environment visitor argument.
   593      *  @param resultInfo   The result info visitor argument.
   594      */
   595     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
   596         Env<AttrContext> prevEnv = this.env;
   597         ResultInfo prevResult = this.resultInfo;
   598         try {
   599             this.env = env;
   600             this.resultInfo = resultInfo;
   601             tree.accept(this);
   602             if (tree == breakTree &&
   603                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
   604                 throw new BreakAttr(env);
   605             }
   606             return result;
   607         } catch (CompletionFailure ex) {
   608             tree.type = syms.errType;
   609             return chk.completionError(tree.pos(), ex);
   610         } finally {
   611             this.env = prevEnv;
   612             this.resultInfo = prevResult;
   613         }
   614     }
   616     /** Derived visitor method: attribute an expression tree.
   617      */
   618     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
   619         return attribTree(tree, env, new ResultInfo(VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
   620     }
   622     /** Derived visitor method: attribute an expression tree with
   623      *  no constraints on the computed type.
   624      */
   625     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
   626         return attribTree(tree, env, unknownExprInfo);
   627     }
   629     /** Derived visitor method: attribute a type tree.
   630      */
   631     public Type attribType(JCTree tree, Env<AttrContext> env) {
   632         Type result = attribType(tree, env, Type.noType);
   633         return result;
   634     }
   636     /** Derived visitor method: attribute a type tree.
   637      */
   638     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
   639         Type result = attribTree(tree, env, new ResultInfo(TYP, pt));
   640         return result;
   641     }
   643     /** Derived visitor method: attribute a statement or definition tree.
   644      */
   645     public Type attribStat(JCTree tree, Env<AttrContext> env) {
   646         return attribTree(tree, env, statInfo);
   647     }
   649     /** Attribute a list of expressions, returning a list of types.
   650      */
   651     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
   652         ListBuffer<Type> ts = new ListBuffer<Type>();
   653         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
   654             ts.append(attribExpr(l.head, env, pt));
   655         return ts.toList();
   656     }
   658     /** Attribute a list of statements, returning nothing.
   659      */
   660     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
   661         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
   662             attribStat(l.head, env);
   663     }
   665     /** Attribute the arguments in a method call, returning a list of types.
   666      */
   667     List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
   668         ListBuffer<Type> argtypes = new ListBuffer<Type>();
   669         for (JCExpression arg : trees) {
   670             Type argtype = allowPoly && TreeInfo.isPoly(arg, env.tree) ?
   671                     deferredAttr.new DeferredType(arg, env) :
   672                     chk.checkNonVoid(arg, attribExpr(arg, env, Infer.anyPoly));
   673             argtypes.append(argtype);
   674         }
   675         return argtypes.toList();
   676     }
   678     /** Attribute a type argument list, returning a list of types.
   679      *  Caller is responsible for calling checkRefTypes.
   680      */
   681     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
   682         ListBuffer<Type> argtypes = new ListBuffer<Type>();
   683         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
   684             argtypes.append(attribType(l.head, env));
   685         return argtypes.toList();
   686     }
   688     /** Attribute a type argument list, returning a list of types.
   689      *  Check that all the types are references.
   690      */
   691     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
   692         List<Type> types = attribAnyTypes(trees, env);
   693         return chk.checkRefTypes(trees, types);
   694     }
   696     /**
   697      * Attribute type variables (of generic classes or methods).
   698      * Compound types are attributed later in attribBounds.
   699      * @param typarams the type variables to enter
   700      * @param env      the current environment
   701      */
   702     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
   703         for (JCTypeParameter tvar : typarams) {
   704             TypeVar a = (TypeVar)tvar.type;
   705             a.tsym.flags_field |= UNATTRIBUTED;
   706             a.bound = Type.noType;
   707             if (!tvar.bounds.isEmpty()) {
   708                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
   709                 for (JCExpression bound : tvar.bounds.tail)
   710                     bounds = bounds.prepend(attribType(bound, env));
   711                 types.setBounds(a, bounds.reverse());
   712             } else {
   713                 // if no bounds are given, assume a single bound of
   714                 // java.lang.Object.
   715                 types.setBounds(a, List.of(syms.objectType));
   716             }
   717             a.tsym.flags_field &= ~UNATTRIBUTED;
   718         }
   719         for (JCTypeParameter tvar : typarams) {
   720             chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
   721         }
   722     }
   724     /**
   725      * Attribute the type references in a list of annotations.
   726      */
   727     void attribAnnotationTypes(List<JCAnnotation> annotations,
   728                                Env<AttrContext> env) {
   729         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
   730             JCAnnotation a = al.head;
   731             attribType(a.annotationType, env);
   732         }
   733     }
   735     /**
   736      * Attribute a "lazy constant value".
   737      *  @param env         The env for the const value
   738      *  @param initializer The initializer for the const value
   739      *  @param type        The expected type, or null
   740      *  @see VarSymbol#setLazyConstValue
   741      */
   742     public Object attribLazyConstantValue(Env<AttrContext> env,
   743                                       JCTree.JCExpression initializer,
   744                                       Type type) {
   746         // in case no lint value has been set up for this env, scan up
   747         // env stack looking for smallest enclosing env for which it is set.
   748         Env<AttrContext> lintEnv = env;
   749         while (lintEnv.info.lint == null)
   750             lintEnv = lintEnv.next;
   752         // Having found the enclosing lint value, we can initialize the lint value for this class
   753         // ... but ...
   754         // There's a problem with evaluating annotations in the right order, such that
   755         // env.info.enclVar.attributes_field might not yet have been evaluated, and so might be
   756         // null. In that case, calling augment will throw an NPE. To avoid this, for now we
   757         // revert to the jdk 6 behavior and ignore the (unevaluated) attributes.
   758         if (env.info.enclVar.annotations.pendingCompletion()) {
   759             env.info.lint = lintEnv.info.lint;
   760         } else {
   761             env.info.lint = lintEnv.info.lint.augment(env.info.enclVar.annotations,
   762                                                       env.info.enclVar.flags());
   763         }
   765         Lint prevLint = chk.setLint(env.info.lint);
   766         JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
   768         try {
   769             Type itype = attribExpr(initializer, env, type);
   770             if (itype.constValue() != null)
   771                 return coerce(itype, type).constValue();
   772             else
   773                 return null;
   774         } finally {
   775             env.info.lint = prevLint;
   776             log.useSource(prevSource);
   777         }
   778     }
   780     /** Attribute type reference in an `extends' or `implements' clause.
   781      *  Supertypes of anonymous inner classes are usually already attributed.
   782      *
   783      *  @param tree              The tree making up the type reference.
   784      *  @param env               The environment current at the reference.
   785      *  @param classExpected     true if only a class is expected here.
   786      *  @param interfaceExpected true if only an interface is expected here.
   787      */
   788     Type attribBase(JCTree tree,
   789                     Env<AttrContext> env,
   790                     boolean classExpected,
   791                     boolean interfaceExpected,
   792                     boolean checkExtensible) {
   793         Type t = tree.type != null ?
   794             tree.type :
   795             attribType(tree, env);
   796         return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
   797     }
   798     Type checkBase(Type t,
   799                    JCTree tree,
   800                    Env<AttrContext> env,
   801                    boolean classExpected,
   802                    boolean interfaceExpected,
   803                    boolean checkExtensible) {
   804         if (t.isErroneous())
   805             return t;
   806         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
   807             // check that type variable is already visible
   808             if (t.getUpperBound() == null) {
   809                 log.error(tree.pos(), "illegal.forward.ref");
   810                 return types.createErrorType(t);
   811             }
   812         } else {
   813             t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics);
   814         }
   815         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
   816             log.error(tree.pos(), "intf.expected.here");
   817             // return errType is necessary since otherwise there might
   818             // be undetected cycles which cause attribution to loop
   819             return types.createErrorType(t);
   820         } else if (checkExtensible &&
   821                    classExpected &&
   822                    (t.tsym.flags() & INTERFACE) != 0) {
   823                 log.error(tree.pos(), "no.intf.expected.here");
   824             return types.createErrorType(t);
   825         }
   826         if (checkExtensible &&
   827             ((t.tsym.flags() & FINAL) != 0)) {
   828             log.error(tree.pos(),
   829                       "cant.inherit.from.final", t.tsym);
   830         }
   831         chk.checkNonCyclic(tree.pos(), t);
   832         return t;
   833     }
   835     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
   836         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
   837         id.type = env.info.scope.owner.type;
   838         id.sym = env.info.scope.owner;
   839         return id.type;
   840     }
   842     public void visitClassDef(JCClassDecl tree) {
   843         // Local classes have not been entered yet, so we need to do it now:
   844         if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
   845             enter.classEnter(tree, env);
   847         ClassSymbol c = tree.sym;
   848         if (c == null) {
   849             // exit in case something drastic went wrong during enter.
   850             result = null;
   851         } else {
   852             // make sure class has been completed:
   853             c.complete();
   855             // If this class appears as an anonymous class
   856             // in a superclass constructor call where
   857             // no explicit outer instance is given,
   858             // disable implicit outer instance from being passed.
   859             // (This would be an illegal access to "this before super").
   860             if (env.info.isSelfCall &&
   861                 env.tree.hasTag(NEWCLASS) &&
   862                 ((JCNewClass) env.tree).encl == null)
   863             {
   864                 c.flags_field |= NOOUTERTHIS;
   865             }
   866             attribClass(tree.pos(), c);
   867             result = tree.type = c.type;
   868         }
   869     }
   871     public void visitMethodDef(JCMethodDecl tree) {
   872         MethodSymbol m = tree.sym;
   873         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
   875         Lint lint = env.info.lint.augment(m.annotations, m.flags());
   876         Lint prevLint = chk.setLint(lint);
   877         MethodSymbol prevMethod = chk.setMethod(m);
   878         try {
   879             deferredLintHandler.flush(tree.pos());
   880             chk.checkDeprecatedAnnotation(tree.pos(), m);
   882             // Create a new environment with local scope
   883             // for attributing the method.
   884             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
   885             localEnv.info.lint = lint;
   887             attribStats(tree.typarams, localEnv);
   889             // If we override any other methods, check that we do so properly.
   890             // JLS ???
   891             if (m.isStatic()) {
   892                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
   893             } else {
   894                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
   895             }
   896             chk.checkOverride(tree, m);
   898             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
   899                 log.error(tree, "default.overrides.object.member", m.name, Kinds.kindName(m.location()), m.location());
   900             }
   902             // Enter all type parameters into the local method scope.
   903             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
   904                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
   906             ClassSymbol owner = env.enclClass.sym;
   907             if ((owner.flags() & ANNOTATION) != 0 &&
   908                 tree.params.nonEmpty())
   909                 log.error(tree.params.head.pos(),
   910                           "intf.annotation.members.cant.have.params");
   912             // Attribute all value parameters.
   913             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
   914                 attribStat(l.head, localEnv);
   915             }
   917             chk.checkVarargsMethodDecl(localEnv, tree);
   919             // Check that type parameters are well-formed.
   920             chk.validate(tree.typarams, localEnv);
   922             // Check that result type is well-formed.
   923             chk.validate(tree.restype, localEnv);
   925             // annotation method checks
   926             if ((owner.flags() & ANNOTATION) != 0) {
   927                 // annotation method cannot have throws clause
   928                 if (tree.thrown.nonEmpty()) {
   929                     log.error(tree.thrown.head.pos(),
   930                             "throws.not.allowed.in.intf.annotation");
   931                 }
   932                 // annotation method cannot declare type-parameters
   933                 if (tree.typarams.nonEmpty()) {
   934                     log.error(tree.typarams.head.pos(),
   935                             "intf.annotation.members.cant.have.type.params");
   936                 }
   937                 // validate annotation method's return type (could be an annotation type)
   938                 chk.validateAnnotationType(tree.restype);
   939                 // ensure that annotation method does not clash with members of Object/Annotation
   940                 chk.validateAnnotationMethod(tree.pos(), m);
   942                 if (tree.defaultValue != null) {
   943                     // if default value is an annotation, check it is a well-formed
   944                     // annotation value (e.g. no duplicate values, no missing values, etc.)
   945                     chk.validateAnnotationTree(tree.defaultValue);
   946                 }
   947             }
   949             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
   950                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
   952             if (tree.body == null) {
   953                 // Empty bodies are only allowed for
   954                 // abstract, native, or interface methods, or for methods
   955                 // in a retrofit signature class.
   956                 if (isDefaultMethod || ((owner.flags() & INTERFACE) == 0 &&
   957                     (tree.mods.flags & (ABSTRACT | NATIVE)) == 0) &&
   958                     !relax)
   959                     log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
   960                 if (tree.defaultValue != null) {
   961                     if ((owner.flags() & ANNOTATION) == 0)
   962                         log.error(tree.pos(),
   963                                   "default.allowed.in.intf.annotation.member");
   964                 }
   965             } else if ((tree.sym.flags() & ABSTRACT) != 0 && !isDefaultMethod) {
   966                 if ((owner.flags() & INTERFACE) != 0) {
   967                     log.error(tree.body.pos(), "intf.meth.cant.have.body");
   968                 } else {
   969                     log.error(tree.pos(), "abstract.meth.cant.have.body");
   970                 }
   971             } else if ((tree.mods.flags & NATIVE) != 0) {
   972                 log.error(tree.pos(), "native.meth.cant.have.body");
   973             } else {
   974                 // Add an implicit super() call unless an explicit call to
   975                 // super(...) or this(...) is given
   976                 // or we are compiling class java.lang.Object.
   977                 if (tree.name == names.init && owner.type != syms.objectType) {
   978                     JCBlock body = tree.body;
   979                     if (body.stats.isEmpty() ||
   980                         !TreeInfo.isSelfCall(body.stats.head)) {
   981                         body.stats = body.stats.
   982                             prepend(memberEnter.SuperCall(make.at(body.pos),
   983                                                           List.<Type>nil(),
   984                                                           List.<JCVariableDecl>nil(),
   985                                                           false));
   986                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
   987                                (tree.mods.flags & GENERATEDCONSTR) == 0 &&
   988                                TreeInfo.isSuperCall(body.stats.head)) {
   989                         // enum constructors are not allowed to call super
   990                         // directly, so make sure there aren't any super calls
   991                         // in enum constructors, except in the compiler
   992                         // generated one.
   993                         log.error(tree.body.stats.head.pos(),
   994                                   "call.to.super.not.allowed.in.enum.ctor",
   995                                   env.enclClass.sym);
   996                     }
   997                 }
   999                 // Attribute method body.
  1000                 attribStat(tree.body, localEnv);
  1002             localEnv.info.scope.leave();
  1003             result = tree.type = m.type;
  1004             chk.validateAnnotations(tree.mods.annotations, m);
  1006         finally {
  1007             chk.setLint(prevLint);
  1008             chk.setMethod(prevMethod);
  1012     public void visitVarDef(JCVariableDecl tree) {
  1013         // Local variables have not been entered yet, so we need to do it now:
  1014         if (env.info.scope.owner.kind == MTH) {
  1015             if (tree.sym != null) {
  1016                 // parameters have already been entered
  1017                 env.info.scope.enter(tree.sym);
  1018             } else {
  1019                 memberEnter.memberEnter(tree, env);
  1020                 annotate.flush();
  1024         VarSymbol v = tree.sym;
  1025         Lint lint = env.info.lint.augment(v.annotations, v.flags());
  1026         Lint prevLint = chk.setLint(lint);
  1028         // Check that the variable's declared type is well-formed.
  1029         chk.validate(tree.vartype, env);
  1030         deferredLintHandler.flush(tree.pos());
  1032         try {
  1033             chk.checkDeprecatedAnnotation(tree.pos(), v);
  1035             if (tree.init != null) {
  1036                 if ((v.flags_field & FINAL) != 0 &&
  1037                         !tree.init.hasTag(NEWCLASS) &&
  1038                         !tree.init.hasTag(LAMBDA) &&
  1039                         !tree.init.hasTag(REFERENCE)) {
  1040                     // In this case, `v' is final.  Ensure that it's initializer is
  1041                     // evaluated.
  1042                     v.getConstValue(); // ensure initializer is evaluated
  1043                 } else {
  1044                     // Attribute initializer in a new environment
  1045                     // with the declared variable as owner.
  1046                     // Check that initializer conforms to variable's declared type.
  1047                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
  1048                     initEnv.info.lint = lint;
  1049                     // In order to catch self-references, we set the variable's
  1050                     // declaration position to maximal possible value, effectively
  1051                     // marking the variable as undefined.
  1052                     initEnv.info.enclVar = v;
  1053                     attribExpr(tree.init, initEnv, v.type);
  1056             result = tree.type = v.type;
  1057             chk.validateAnnotations(tree.mods.annotations, v);
  1059         finally {
  1060             chk.setLint(prevLint);
  1064     public void visitSkip(JCSkip tree) {
  1065         result = null;
  1068     public void visitBlock(JCBlock tree) {
  1069         if (env.info.scope.owner.kind == TYP) {
  1070             // Block is a static or instance initializer;
  1071             // let the owner of the environment be a freshly
  1072             // created BLOCK-method.
  1073             Env<AttrContext> localEnv =
  1074                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared()));
  1075             localEnv.info.scope.owner =
  1076                 new MethodSymbol(tree.flags | BLOCK, names.empty, null,
  1077                                  env.info.scope.owner);
  1078             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
  1079             attribStats(tree.stats, localEnv);
  1080         } else {
  1081             // Create a new local environment with a local scope.
  1082             Env<AttrContext> localEnv =
  1083                 env.dup(tree, env.info.dup(env.info.scope.dup()));
  1084             try {
  1085                 attribStats(tree.stats, localEnv);
  1086             } finally {
  1087                 localEnv.info.scope.leave();
  1090         result = null;
  1093     public void visitDoLoop(JCDoWhileLoop tree) {
  1094         attribStat(tree.body, env.dup(tree));
  1095         attribExpr(tree.cond, env, syms.booleanType);
  1096         result = null;
  1099     public void visitWhileLoop(JCWhileLoop tree) {
  1100         attribExpr(tree.cond, env, syms.booleanType);
  1101         attribStat(tree.body, env.dup(tree));
  1102         result = null;
  1105     public void visitForLoop(JCForLoop tree) {
  1106         Env<AttrContext> loopEnv =
  1107             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
  1108         try {
  1109             attribStats(tree.init, loopEnv);
  1110             if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType);
  1111             loopEnv.tree = tree; // before, we were not in loop!
  1112             attribStats(tree.step, loopEnv);
  1113             attribStat(tree.body, loopEnv);
  1114             result = null;
  1116         finally {
  1117             loopEnv.info.scope.leave();
  1121     public void visitForeachLoop(JCEnhancedForLoop tree) {
  1122         Env<AttrContext> loopEnv =
  1123             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
  1124         try {
  1125             attribStat(tree.var, loopEnv);
  1126             Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
  1127             chk.checkNonVoid(tree.pos(), exprType);
  1128             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
  1129             if (elemtype == null) {
  1130                 // or perhaps expr implements Iterable<T>?
  1131                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
  1132                 if (base == null) {
  1133                     log.error(tree.expr.pos(),
  1134                             "foreach.not.applicable.to.type",
  1135                             exprType,
  1136                             diags.fragment("type.req.array.or.iterable"));
  1137                     elemtype = types.createErrorType(exprType);
  1138                 } else {
  1139                     List<Type> iterableParams = base.allparams();
  1140                     elemtype = iterableParams.isEmpty()
  1141                         ? syms.objectType
  1142                         : types.upperBound(iterableParams.head);
  1145             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
  1146             loopEnv.tree = tree; // before, we were not in loop!
  1147             attribStat(tree.body, loopEnv);
  1148             result = null;
  1150         finally {
  1151             loopEnv.info.scope.leave();
  1155     public void visitLabelled(JCLabeledStatement tree) {
  1156         // Check that label is not used in an enclosing statement
  1157         Env<AttrContext> env1 = env;
  1158         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
  1159             if (env1.tree.hasTag(LABELLED) &&
  1160                 ((JCLabeledStatement) env1.tree).label == tree.label) {
  1161                 log.error(tree.pos(), "label.already.in.use",
  1162                           tree.label);
  1163                 break;
  1165             env1 = env1.next;
  1168         attribStat(tree.body, env.dup(tree));
  1169         result = null;
  1172     public void visitSwitch(JCSwitch tree) {
  1173         Type seltype = attribExpr(tree.selector, env);
  1175         Env<AttrContext> switchEnv =
  1176             env.dup(tree, env.info.dup(env.info.scope.dup()));
  1178         try {
  1180             boolean enumSwitch =
  1181                 allowEnums &&
  1182                 (seltype.tsym.flags() & Flags.ENUM) != 0;
  1183             boolean stringSwitch = false;
  1184             if (types.isSameType(seltype, syms.stringType)) {
  1185                 if (allowStringsInSwitch) {
  1186                     stringSwitch = true;
  1187                 } else {
  1188                     log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName);
  1191             if (!enumSwitch && !stringSwitch)
  1192                 seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);
  1194             // Attribute all cases and
  1195             // check that there are no duplicate case labels or default clauses.
  1196             Set<Object> labels = new HashSet<Object>(); // The set of case labels.
  1197             boolean hasDefault = false;      // Is there a default label?
  1198             for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
  1199                 JCCase c = l.head;
  1200                 Env<AttrContext> caseEnv =
  1201                     switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
  1202                 try {
  1203                     if (c.pat != null) {
  1204                         if (enumSwitch) {
  1205                             Symbol sym = enumConstant(c.pat, seltype);
  1206                             if (sym == null) {
  1207                                 log.error(c.pat.pos(), "enum.label.must.be.unqualified.enum");
  1208                             } else if (!labels.add(sym)) {
  1209                                 log.error(c.pos(), "duplicate.case.label");
  1211                         } else {
  1212                             Type pattype = attribExpr(c.pat, switchEnv, seltype);
  1213                             if (!pattype.hasTag(ERROR)) {
  1214                                 if (pattype.constValue() == null) {
  1215                                     log.error(c.pat.pos(),
  1216                                               (stringSwitch ? "string.const.req" : "const.expr.req"));
  1217                                 } else if (labels.contains(pattype.constValue())) {
  1218                                     log.error(c.pos(), "duplicate.case.label");
  1219                                 } else {
  1220                                     labels.add(pattype.constValue());
  1224                     } else if (hasDefault) {
  1225                         log.error(c.pos(), "duplicate.default.label");
  1226                     } else {
  1227                         hasDefault = true;
  1229                     attribStats(c.stats, caseEnv);
  1230                 } finally {
  1231                     caseEnv.info.scope.leave();
  1232                     addVars(c.stats, switchEnv.info.scope);
  1236             result = null;
  1238         finally {
  1239             switchEnv.info.scope.leave();
  1242     // where
  1243         /** Add any variables defined in stats to the switch scope. */
  1244         private static void addVars(List<JCStatement> stats, Scope switchScope) {
  1245             for (;stats.nonEmpty(); stats = stats.tail) {
  1246                 JCTree stat = stats.head;
  1247                 if (stat.hasTag(VARDEF))
  1248                     switchScope.enter(((JCVariableDecl) stat).sym);
  1251     // where
  1252     /** Return the selected enumeration constant symbol, or null. */
  1253     private Symbol enumConstant(JCTree tree, Type enumType) {
  1254         if (!tree.hasTag(IDENT)) {
  1255             log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
  1256             return syms.errSymbol;
  1258         JCIdent ident = (JCIdent)tree;
  1259         Name name = ident.name;
  1260         for (Scope.Entry e = enumType.tsym.members().lookup(name);
  1261              e.scope != null; e = e.next()) {
  1262             if (e.sym.kind == VAR) {
  1263                 Symbol s = ident.sym = e.sym;
  1264                 ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
  1265                 ident.type = s.type;
  1266                 return ((s.flags_field & Flags.ENUM) == 0)
  1267                     ? null : s;
  1270         return null;
  1273     public void visitSynchronized(JCSynchronized tree) {
  1274         chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
  1275         attribStat(tree.body, env);
  1276         result = null;
  1279     public void visitTry(JCTry tree) {
  1280         // Create a new local environment with a local
  1281         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
  1282         try {
  1283             boolean isTryWithResource = tree.resources.nonEmpty();
  1284             // Create a nested environment for attributing the try block if needed
  1285             Env<AttrContext> tryEnv = isTryWithResource ?
  1286                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
  1287                 localEnv;
  1288             try {
  1289                 // Attribute resource declarations
  1290                 for (JCTree resource : tree.resources) {
  1291                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
  1292                         @Override
  1293                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
  1294                             chk.basicHandler.report(pos, diags.fragment("try.not.applicable.to.type", details));
  1296                     };
  1297                     ResultInfo twrResult = new ResultInfo(VAL, syms.autoCloseableType, twrContext);
  1298                     if (resource.hasTag(VARDEF)) {
  1299                         attribStat(resource, tryEnv);
  1300                         twrResult.check(resource, resource.type);
  1302                         //check that resource type cannot throw InterruptedException
  1303                         checkAutoCloseable(resource.pos(), localEnv, resource.type);
  1305                         VarSymbol var = (VarSymbol)TreeInfo.symbolFor(resource);
  1306                         var.setData(ElementKind.RESOURCE_VARIABLE);
  1307                     } else {
  1308                         attribTree(resource, tryEnv, twrResult);
  1311                 // Attribute body
  1312                 attribStat(tree.body, tryEnv);
  1313             } finally {
  1314                 if (isTryWithResource)
  1315                     tryEnv.info.scope.leave();
  1318             // Attribute catch clauses
  1319             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
  1320                 JCCatch c = l.head;
  1321                 Env<AttrContext> catchEnv =
  1322                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
  1323                 try {
  1324                     Type ctype = attribStat(c.param, catchEnv);
  1325                     if (TreeInfo.isMultiCatch(c)) {
  1326                         //multi-catch parameter is implicitly marked as final
  1327                         c.param.sym.flags_field |= FINAL | UNION;
  1329                     if (c.param.sym.kind == Kinds.VAR) {
  1330                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
  1332                     chk.checkType(c.param.vartype.pos(),
  1333                                   chk.checkClassType(c.param.vartype.pos(), ctype),
  1334                                   syms.throwableType);
  1335                     attribStat(c.body, catchEnv);
  1336                 } finally {
  1337                     catchEnv.info.scope.leave();
  1341             // Attribute finalizer
  1342             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
  1343             result = null;
  1345         finally {
  1346             localEnv.info.scope.leave();
  1350     void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
  1351         if (!resource.isErroneous() &&
  1352             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
  1353             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
  1354             Symbol close = syms.noSymbol;
  1355             Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log);
  1356             try {
  1357                 close = rs.resolveQualifiedMethod(pos,
  1358                         env,
  1359                         resource,
  1360                         names.close,
  1361                         List.<Type>nil(),
  1362                         List.<Type>nil());
  1364             finally {
  1365                 log.popDiagnosticHandler(discardHandler);
  1367             if (close.kind == MTH &&
  1368                     close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
  1369                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
  1370                     env.info.lint.isEnabled(LintCategory.TRY)) {
  1371                 log.warning(LintCategory.TRY, pos, "try.resource.throws.interrupted.exc", resource);
  1376     public void visitConditional(JCConditional tree) {
  1377         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
  1379         boolean standaloneConditional = !allowPoly ||
  1380                 pt().hasTag(NONE) && pt() != Type.recoveryType ||
  1381                 isBooleanOrNumeric(env, tree);
  1383         if (!standaloneConditional && resultInfo.pt.hasTag(VOID)) {
  1384             //cannot get here (i.e. it means we are returning from void method - which is already an error)
  1385             resultInfo.checkContext.report(tree, diags.fragment("conditional.target.cant.be.void"));
  1386             result = tree.type = types.createErrorType(resultInfo.pt);
  1387             return;
  1390         ResultInfo condInfo = standaloneConditional ?
  1391                 unknownExprInfo :
  1392                 resultInfo.dup(new Check.NestedCheckContext(resultInfo.checkContext) {
  1393                     //this will use enclosing check context to check compatibility of
  1394                     //subexpression against target type; if we are in a method check context,
  1395                     //depending on whether boxing is allowed, we could have incompatibilities
  1396                     @Override
  1397                     public void report(DiagnosticPosition pos, JCDiagnostic details) {
  1398                         enclosingContext.report(pos, diags.fragment("incompatible.type.in.conditional", details));
  1400                 });
  1402         Type truetype = attribTree(tree.truepart, env, condInfo);
  1403         Type falsetype = attribTree(tree.falsepart, env, condInfo);
  1405         Type owntype = standaloneConditional ? condType(tree, truetype, falsetype) : pt();
  1406         if (condtype.constValue() != null &&
  1407                 truetype.constValue() != null &&
  1408                 falsetype.constValue() != null &&
  1409                 !owntype.hasTag(NONE)) {
  1410             //constant folding
  1411             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
  1413         result = check(tree, owntype, VAL, resultInfo);
  1415     //where
  1416         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
  1417             switch (tree.getTag()) {
  1418                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
  1419                               ((JCLiteral)tree).typetag == BOOLEAN ||
  1420                               ((JCLiteral)tree).typetag == BOT;
  1421                 case LAMBDA: case REFERENCE: return false;
  1422                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
  1423                 case CONDEXPR:
  1424                     JCConditional condTree = (JCConditional)tree;
  1425                     return isBooleanOrNumeric(env, condTree.truepart) &&
  1426                             isBooleanOrNumeric(env, condTree.falsepart);
  1427                 default:
  1428                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo).type;
  1429                     speculativeType = types.unboxedTypeOrType(speculativeType);
  1430                     return speculativeType.isPrimitive();
  1434         /** Compute the type of a conditional expression, after
  1435          *  checking that it exists.  See JLS 15.25. Does not take into
  1436          *  account the special case where condition and both arms
  1437          *  are constants.
  1439          *  @param pos      The source position to be used for error
  1440          *                  diagnostics.
  1441          *  @param thentype The type of the expression's then-part.
  1442          *  @param elsetype The type of the expression's else-part.
  1443          */
  1444         private Type condType(DiagnosticPosition pos,
  1445                                Type thentype, Type elsetype) {
  1446             // If same type, that is the result
  1447             if (types.isSameType(thentype, elsetype))
  1448                 return thentype.baseType();
  1450             Type thenUnboxed = (!allowBoxing || thentype.isPrimitive())
  1451                 ? thentype : types.unboxedType(thentype);
  1452             Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive())
  1453                 ? elsetype : types.unboxedType(elsetype);
  1455             // Otherwise, if both arms can be converted to a numeric
  1456             // type, return the least numeric type that fits both arms
  1457             // (i.e. return larger of the two, or return int if one
  1458             // arm is short, the other is char).
  1459             if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
  1460                 // If one arm has an integer subrange type (i.e., byte,
  1461                 // short, or char), and the other is an integer constant
  1462                 // that fits into the subrange, return the subrange type.
  1463                 if (thenUnboxed.getTag().isStrictSubRangeOf(INT) && elseUnboxed.hasTag(INT) &&
  1464                     types.isAssignable(elseUnboxed, thenUnboxed))
  1465                     return thenUnboxed.baseType();
  1466                 if (elseUnboxed.getTag().isStrictSubRangeOf(INT) && thenUnboxed.hasTag(INT) &&
  1467                     types.isAssignable(thenUnboxed, elseUnboxed))
  1468                     return elseUnboxed.baseType();
  1470                 for (TypeTag tag : TypeTag.values()) {
  1471                     if (tag.ordinal() >= TypeTag.getTypeTagCount()) break;
  1472                     Type candidate = syms.typeOfTag[tag.ordinal()];
  1473                     if (candidate != null &&
  1474                         candidate.isPrimitive() &&
  1475                         types.isSubtype(thenUnboxed, candidate) &&
  1476                         types.isSubtype(elseUnboxed, candidate))
  1477                         return candidate;
  1481             // Those were all the cases that could result in a primitive
  1482             if (allowBoxing) {
  1483                 if (thentype.isPrimitive())
  1484                     thentype = types.boxedClass(thentype).type;
  1485                 if (elsetype.isPrimitive())
  1486                     elsetype = types.boxedClass(elsetype).type;
  1489             if (types.isSubtype(thentype, elsetype))
  1490                 return elsetype.baseType();
  1491             if (types.isSubtype(elsetype, thentype))
  1492                 return thentype.baseType();
  1494             if (!allowBoxing || thentype.hasTag(VOID) || elsetype.hasTag(VOID)) {
  1495                 log.error(pos, "neither.conditional.subtype",
  1496                           thentype, elsetype);
  1497                 return thentype.baseType();
  1500             // both are known to be reference types.  The result is
  1501             // lub(thentype,elsetype). This cannot fail, as it will
  1502             // always be possible to infer "Object" if nothing better.
  1503             return types.lub(thentype.baseType(), elsetype.baseType());
  1506     public void visitIf(JCIf tree) {
  1507         attribExpr(tree.cond, env, syms.booleanType);
  1508         attribStat(tree.thenpart, env);
  1509         if (tree.elsepart != null)
  1510             attribStat(tree.elsepart, env);
  1511         chk.checkEmptyIf(tree);
  1512         result = null;
  1515     public void visitExec(JCExpressionStatement tree) {
  1516         //a fresh environment is required for 292 inference to work properly ---
  1517         //see Infer.instantiatePolymorphicSignatureInstance()
  1518         Env<AttrContext> localEnv = env.dup(tree);
  1519         attribExpr(tree.expr, localEnv);
  1520         result = null;
  1523     public void visitBreak(JCBreak tree) {
  1524         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
  1525         result = null;
  1528     public void visitContinue(JCContinue tree) {
  1529         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
  1530         result = null;
  1532     //where
  1533         /** Return the target of a break or continue statement, if it exists,
  1534          *  report an error if not.
  1535          *  Note: The target of a labelled break or continue is the
  1536          *  (non-labelled) statement tree referred to by the label,
  1537          *  not the tree representing the labelled statement itself.
  1539          *  @param pos     The position to be used for error diagnostics
  1540          *  @param tag     The tag of the jump statement. This is either
  1541          *                 Tree.BREAK or Tree.CONTINUE.
  1542          *  @param label   The label of the jump statement, or null if no
  1543          *                 label is given.
  1544          *  @param env     The environment current at the jump statement.
  1545          */
  1546         private JCTree findJumpTarget(DiagnosticPosition pos,
  1547                                     JCTree.Tag tag,
  1548                                     Name label,
  1549                                     Env<AttrContext> env) {
  1550             // Search environments outwards from the point of jump.
  1551             Env<AttrContext> env1 = env;
  1552             LOOP:
  1553             while (env1 != null) {
  1554                 switch (env1.tree.getTag()) {
  1555                     case LABELLED:
  1556                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
  1557                         if (label == labelled.label) {
  1558                             // If jump is a continue, check that target is a loop.
  1559                             if (tag == CONTINUE) {
  1560                                 if (!labelled.body.hasTag(DOLOOP) &&
  1561                                         !labelled.body.hasTag(WHILELOOP) &&
  1562                                         !labelled.body.hasTag(FORLOOP) &&
  1563                                         !labelled.body.hasTag(FOREACHLOOP))
  1564                                     log.error(pos, "not.loop.label", label);
  1565                                 // Found labelled statement target, now go inwards
  1566                                 // to next non-labelled tree.
  1567                                 return TreeInfo.referencedStatement(labelled);
  1568                             } else {
  1569                                 return labelled;
  1572                         break;
  1573                     case DOLOOP:
  1574                     case WHILELOOP:
  1575                     case FORLOOP:
  1576                     case FOREACHLOOP:
  1577                         if (label == null) return env1.tree;
  1578                         break;
  1579                     case SWITCH:
  1580                         if (label == null && tag == BREAK) return env1.tree;
  1581                         break;
  1582                     case LAMBDA:
  1583                     case METHODDEF:
  1584                     case CLASSDEF:
  1585                         break LOOP;
  1586                     default:
  1588                 env1 = env1.next;
  1590             if (label != null)
  1591                 log.error(pos, "undef.label", label);
  1592             else if (tag == CONTINUE)
  1593                 log.error(pos, "cont.outside.loop");
  1594             else
  1595                 log.error(pos, "break.outside.switch.loop");
  1596             return null;
  1599     public void visitReturn(JCReturn tree) {
  1600         // Check that there is an enclosing method which is
  1601         // nested within than the enclosing class.
  1602         if (env.info.returnResult == null) {
  1603             log.error(tree.pos(), "ret.outside.meth");
  1604         } else {
  1605             // Attribute return expression, if it exists, and check that
  1606             // it conforms to result type of enclosing method.
  1607             if (tree.expr != null) {
  1608                 if (env.info.returnResult.pt.hasTag(VOID)) {
  1609                     env.info.returnResult.checkContext.report(tree.expr.pos(),
  1610                               diags.fragment("unexpected.ret.val"));
  1612                 attribTree(tree.expr, env, env.info.returnResult);
  1613             } else if (!env.info.returnResult.pt.hasTag(VOID)) {
  1614                 env.info.returnResult.checkContext.report(tree.pos(),
  1615                               diags.fragment("missing.ret.val"));
  1618         result = null;
  1621     public void visitThrow(JCThrow tree) {
  1622         Type owntype = attribExpr(tree.expr, env, allowPoly ? Type.noType : syms.throwableType);
  1623         if (allowPoly) {
  1624             chk.checkType(tree, owntype, syms.throwableType);
  1626         result = null;
  1629     public void visitAssert(JCAssert tree) {
  1630         attribExpr(tree.cond, env, syms.booleanType);
  1631         if (tree.detail != null) {
  1632             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
  1634         result = null;
  1637      /** Visitor method for method invocations.
  1638      *  NOTE: The method part of an application will have in its type field
  1639      *        the return type of the method, not the method's type itself!
  1640      */
  1641     public void visitApply(JCMethodInvocation tree) {
  1642         // The local environment of a method application is
  1643         // a new environment nested in the current one.
  1644         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
  1646         // The types of the actual method arguments.
  1647         List<Type> argtypes;
  1649         // The types of the actual method type arguments.
  1650         List<Type> typeargtypes = null;
  1652         Name methName = TreeInfo.name(tree.meth);
  1654         boolean isConstructorCall =
  1655             methName == names._this || methName == names._super;
  1657         if (isConstructorCall) {
  1658             // We are seeing a ...this(...) or ...super(...) call.
  1659             // Check that this is the first statement in a constructor.
  1660             if (checkFirstConstructorStat(tree, env)) {
  1662                 // Record the fact
  1663                 // that this is a constructor call (using isSelfCall).
  1664                 localEnv.info.isSelfCall = true;
  1666                 // Attribute arguments, yielding list of argument types.
  1667                 argtypes = attribArgs(tree.args, localEnv);
  1668                 typeargtypes = attribTypes(tree.typeargs, localEnv);
  1670                 // Variable `site' points to the class in which the called
  1671                 // constructor is defined.
  1672                 Type site = env.enclClass.sym.type;
  1673                 if (methName == names._super) {
  1674                     if (site == syms.objectType) {
  1675                         log.error(tree.meth.pos(), "no.superclass", site);
  1676                         site = types.createErrorType(syms.objectType);
  1677                     } else {
  1678                         site = types.supertype(site);
  1682                 if (site.hasTag(CLASS)) {
  1683                     Type encl = site.getEnclosingType();
  1684                     while (encl != null && encl.hasTag(TYPEVAR))
  1685                         encl = encl.getUpperBound();
  1686                     if (encl.hasTag(CLASS)) {
  1687                         // we are calling a nested class
  1689                         if (tree.meth.hasTag(SELECT)) {
  1690                             JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
  1692                             // We are seeing a prefixed call, of the form
  1693                             //     <expr>.super(...).
  1694                             // Check that the prefix expression conforms
  1695                             // to the outer instance type of the class.
  1696                             chk.checkRefType(qualifier.pos(),
  1697                                              attribExpr(qualifier, localEnv,
  1698                                                         encl));
  1699                         } else if (methName == names._super) {
  1700                             // qualifier omitted; check for existence
  1701                             // of an appropriate implicit qualifier.
  1702                             rs.resolveImplicitThis(tree.meth.pos(),
  1703                                                    localEnv, site, true);
  1705                     } else if (tree.meth.hasTag(SELECT)) {
  1706                         log.error(tree.meth.pos(), "illegal.qual.not.icls",
  1707                                   site.tsym);
  1710                     // if we're calling a java.lang.Enum constructor,
  1711                     // prefix the implicit String and int parameters
  1712                     if (site.tsym == syms.enumSym && allowEnums)
  1713                         argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
  1715                     // Resolve the called constructor under the assumption
  1716                     // that we are referring to a superclass instance of the
  1717                     // current instance (JLS ???).
  1718                     boolean selectSuperPrev = localEnv.info.selectSuper;
  1719                     localEnv.info.selectSuper = true;
  1720                     localEnv.info.pendingResolutionPhase = null;
  1721                     Symbol sym = rs.resolveConstructor(
  1722                         tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
  1723                     localEnv.info.selectSuper = selectSuperPrev;
  1725                     // Set method symbol to resolved constructor...
  1726                     TreeInfo.setSymbol(tree.meth, sym);
  1728                     // ...and check that it is legal in the current context.
  1729                     // (this will also set the tree's type)
  1730                     Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
  1731                     checkId(tree.meth, site, sym, localEnv, new ResultInfo(MTH, mpt));
  1733                 // Otherwise, `site' is an error type and we do nothing
  1735             result = tree.type = syms.voidType;
  1736         } else {
  1737             // Otherwise, we are seeing a regular method call.
  1738             // Attribute the arguments, yielding list of argument types, ...
  1739             argtypes = attribArgs(tree.args, localEnv);
  1740             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
  1742             // ... and attribute the method using as a prototype a methodtype
  1743             // whose formal argument types is exactly the list of actual
  1744             // arguments (this will also set the method symbol).
  1745             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
  1746             localEnv.info.pendingResolutionPhase = null;
  1747             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(VAL, mpt, resultInfo.checkContext));
  1749             // Compute the result type.
  1750             Type restype = mtype.getReturnType();
  1751             if (restype.hasTag(WILDCARD))
  1752                 throw new AssertionError(mtype);
  1754             Type qualifier = (tree.meth.hasTag(SELECT))
  1755                     ? ((JCFieldAccess) tree.meth).selected.type
  1756                     : env.enclClass.sym.type;
  1757             restype = adjustMethodReturnType(qualifier, methName, argtypes, restype);
  1759             chk.checkRefTypes(tree.typeargs, typeargtypes);
  1761             // Check that value of resulting type is admissible in the
  1762             // current context.  Also, capture the return type
  1763             result = check(tree, capture(restype), VAL, resultInfo);
  1765             if (localEnv.info.lastResolveVarargs())
  1766                 Assert.check(result.isErroneous() || tree.varargsElement != null);
  1768         chk.validate(tree.typeargs, localEnv);
  1770     //where
  1771         Type adjustMethodReturnType(Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
  1772             if (allowCovariantReturns &&
  1773                     methodName == names.clone &&
  1774                 types.isArray(qualifierType)) {
  1775                 // as a special case, array.clone() has a result that is
  1776                 // the same as static type of the array being cloned
  1777                 return qualifierType;
  1778             } else if (allowGenerics &&
  1779                     methodName == names.getClass &&
  1780                     argtypes.isEmpty()) {
  1781                 // as a special case, x.getClass() has type Class<? extends |X|>
  1782                 return new ClassType(restype.getEnclosingType(),
  1783                               List.<Type>of(new WildcardType(types.erasure(qualifierType),
  1784                                                                BoundKind.EXTENDS,
  1785                                                                syms.boundClass)),
  1786                               restype.tsym);
  1787             } else {
  1788                 return restype;
  1792         /** Check that given application node appears as first statement
  1793          *  in a constructor call.
  1794          *  @param tree   The application node
  1795          *  @param env    The environment current at the application.
  1796          */
  1797         boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
  1798             JCMethodDecl enclMethod = env.enclMethod;
  1799             if (enclMethod != null && enclMethod.name == names.init) {
  1800                 JCBlock body = enclMethod.body;
  1801                 if (body.stats.head.hasTag(EXEC) &&
  1802                     ((JCExpressionStatement) body.stats.head).expr == tree)
  1803                     return true;
  1805             log.error(tree.pos(),"call.must.be.first.stmt.in.ctor",
  1806                       TreeInfo.name(tree.meth));
  1807             return false;
  1810         /** Obtain a method type with given argument types.
  1811          */
  1812         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
  1813             MethodType mt = new MethodType(argtypes, restype, List.<Type>nil(), syms.methodClass);
  1814             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
  1817     public void visitNewClass(final JCNewClass tree) {
  1818         Type owntype = types.createErrorType(tree.type);
  1820         // The local environment of a class creation is
  1821         // a new environment nested in the current one.
  1822         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
  1824         // The anonymous inner class definition of the new expression,
  1825         // if one is defined by it.
  1826         JCClassDecl cdef = tree.def;
  1828         // If enclosing class is given, attribute it, and
  1829         // complete class name to be fully qualified
  1830         JCExpression clazz = tree.clazz; // Class field following new
  1831         JCExpression clazzid =          // Identifier in class field
  1832             (clazz.hasTag(TYPEAPPLY))
  1833             ? ((JCTypeApply) clazz).clazz
  1834             : clazz;
  1836         JCExpression clazzid1 = clazzid; // The same in fully qualified form
  1838         if (tree.encl != null) {
  1839             // We are seeing a qualified new, of the form
  1840             //    <expr>.new C <...> (...) ...
  1841             // In this case, we let clazz stand for the name of the
  1842             // allocated class C prefixed with the type of the qualifier
  1843             // expression, so that we can
  1844             // resolve it with standard techniques later. I.e., if
  1845             // <expr> has type T, then <expr>.new C <...> (...)
  1846             // yields a clazz T.C.
  1847             Type encltype = chk.checkRefType(tree.encl.pos(),
  1848                                              attribExpr(tree.encl, env));
  1849             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
  1850                                                  ((JCIdent) clazzid).name);
  1851             if (clazz.hasTag(TYPEAPPLY))
  1852                 clazz = make.at(tree.pos).
  1853                     TypeApply(clazzid1,
  1854                               ((JCTypeApply) clazz).arguments);
  1855             else
  1856                 clazz = clazzid1;
  1859         // Attribute clazz expression and store
  1860         // symbol + type back into the attributed tree.
  1861         Type clazztype = TreeInfo.isEnumInit(env.tree) ?
  1862             attribIdentAsEnumType(env, (JCIdent)clazz) :
  1863             attribType(clazz, env);
  1865         clazztype = chk.checkDiamond(tree, clazztype);
  1866         chk.validate(clazz, localEnv);
  1867         if (tree.encl != null) {
  1868             // We have to work in this case to store
  1869             // symbol + type back into the attributed tree.
  1870             tree.clazz.type = clazztype;
  1871             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
  1872             clazzid.type = ((JCIdent) clazzid).sym.type;
  1873             if (!clazztype.isErroneous()) {
  1874                 if (cdef != null && clazztype.tsym.isInterface()) {
  1875                     log.error(tree.encl.pos(), "anon.class.impl.intf.no.qual.for.new");
  1876                 } else if (clazztype.tsym.isStatic()) {
  1877                     log.error(tree.encl.pos(), "qualified.new.of.static.class", clazztype.tsym);
  1880         } else if (!clazztype.tsym.isInterface() &&
  1881                    clazztype.getEnclosingType().hasTag(CLASS)) {
  1882             // Check for the existence of an apropos outer instance
  1883             rs.resolveImplicitThis(tree.pos(), env, clazztype);
  1886         // Attribute constructor arguments.
  1887         List<Type> argtypes = attribArgs(tree.args, localEnv);
  1888         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
  1890         // If we have made no mistakes in the class type...
  1891         if (clazztype.hasTag(CLASS)) {
  1892             // Enums may not be instantiated except implicitly
  1893             if (allowEnums &&
  1894                 (clazztype.tsym.flags_field&Flags.ENUM) != 0 &&
  1895                 (!env.tree.hasTag(VARDEF) ||
  1896                  (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 ||
  1897                  ((JCVariableDecl) env.tree).init != tree))
  1898                 log.error(tree.pos(), "enum.cant.be.instantiated");
  1899             // Check that class is not abstract
  1900             if (cdef == null &&
  1901                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
  1902                 log.error(tree.pos(), "abstract.cant.be.instantiated",
  1903                           clazztype.tsym);
  1904             } else if (cdef != null && clazztype.tsym.isInterface()) {
  1905                 // Check that no constructor arguments are given to
  1906                 // anonymous classes implementing an interface
  1907                 if (!argtypes.isEmpty())
  1908                     log.error(tree.args.head.pos(), "anon.class.impl.intf.no.args");
  1910                 if (!typeargtypes.isEmpty())
  1911                     log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs");
  1913                 // Error recovery: pretend no arguments were supplied.
  1914                 argtypes = List.nil();
  1915                 typeargtypes = List.nil();
  1916             } else if (TreeInfo.isDiamond(tree)) {
  1917                 ClassType site = new ClassType(clazztype.getEnclosingType(),
  1918                             clazztype.tsym.type.getTypeArguments(),
  1919                             clazztype.tsym);
  1921                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
  1922                 diamondEnv.info.selectSuper = cdef != null;
  1923                 diamondEnv.info.pendingResolutionPhase = null;
  1925                 //if the type of the instance creation expression is a class type
  1926                 //apply method resolution inference (JLS 15.12.2.7). The return type
  1927                 //of the resolved constructor will be a partially instantiated type
  1928                 Symbol constructor = rs.resolveDiamond(tree.pos(),
  1929                             diamondEnv,
  1930                             site,
  1931                             argtypes,
  1932                             typeargtypes);
  1933                 tree.constructor = constructor.baseSymbol();
  1935                 final TypeSymbol csym = clazztype.tsym;
  1936                 ResultInfo diamondResult = new ResultInfo(MTH, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes), new Check.NestedCheckContext(resultInfo.checkContext) {
  1937                     @Override
  1938                     public void report(DiagnosticPosition _unused, JCDiagnostic details) {
  1939                         enclosingContext.report(tree.clazz,
  1940                                 diags.fragment("cant.apply.diamond.1", diags.fragment("diamond", csym), details));
  1942                 });
  1943                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
  1944                 constructorType = checkId(tree, site,
  1945                         constructor,
  1946                         diamondEnv,
  1947                         diamondResult);
  1949                 tree.clazz.type = types.createErrorType(clazztype);
  1950                 if (!constructorType.isErroneous()) {
  1951                     tree.clazz.type = clazztype = constructorType.getReturnType();
  1952                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
  1954                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
  1957             // Resolve the called constructor under the assumption
  1958             // that we are referring to a superclass instance of the
  1959             // current instance (JLS ???).
  1960             else {
  1961                 //the following code alters some of the fields in the current
  1962                 //AttrContext - hence, the current context must be dup'ed in
  1963                 //order to avoid downstream failures
  1964                 Env<AttrContext> rsEnv = localEnv.dup(tree);
  1965                 rsEnv.info.selectSuper = cdef != null;
  1966                 rsEnv.info.pendingResolutionPhase = null;
  1967                 tree.constructor = rs.resolveConstructor(
  1968                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
  1969                 if (cdef == null) { //do not check twice!
  1970                     tree.constructorType = checkId(tree,
  1971                             clazztype,
  1972                             tree.constructor,
  1973                             rsEnv,
  1974                             new ResultInfo(MTH, newMethodTemplate(syms.voidType, argtypes, typeargtypes)));
  1975                     if (rsEnv.info.lastResolveVarargs())
  1976                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
  1978                 findDiamondIfNeeded(localEnv, tree, clazztype);
  1981             if (cdef != null) {
  1982                 // We are seeing an anonymous class instance creation.
  1983                 // In this case, the class instance creation
  1984                 // expression
  1985                 //
  1986                 //    E.new <typeargs1>C<typargs2>(args) { ... }
  1987                 //
  1988                 // is represented internally as
  1989                 //
  1990                 //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
  1991                 //
  1992                 // This expression is then *transformed* as follows:
  1993                 //
  1994                 // (1) add a STATIC flag to the class definition
  1995                 //     if the current environment is static
  1996                 // (2) add an extends or implements clause
  1997                 // (3) add a constructor.
  1998                 //
  1999                 // For instance, if C is a class, and ET is the type of E,
  2000                 // the expression
  2001                 //
  2002                 //    E.new <typeargs1>C<typargs2>(args) { ... }
  2003                 //
  2004                 // is translated to (where X is a fresh name and typarams is the
  2005                 // parameter list of the super constructor):
  2006                 //
  2007                 //   new <typeargs1>X(<*nullchk*>E, args) where
  2008                 //     X extends C<typargs2> {
  2009                 //       <typarams> X(ET e, args) {
  2010                 //         e.<typeargs1>super(args)
  2011                 //       }
  2012                 //       ...
  2013                 //     }
  2014                 if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
  2016                 if (clazztype.tsym.isInterface()) {
  2017                     cdef.implementing = List.of(clazz);
  2018                 } else {
  2019                     cdef.extending = clazz;
  2022                 attribStat(cdef, localEnv);
  2024                 checkLambdaCandidate(tree, cdef.sym, clazztype);
  2026                 // If an outer instance is given,
  2027                 // prefix it to the constructor arguments
  2028                 // and delete it from the new expression
  2029                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
  2030                     tree.args = tree.args.prepend(makeNullCheck(tree.encl));
  2031                     argtypes = argtypes.prepend(tree.encl.type);
  2032                     tree.encl = null;
  2035                 // Reassign clazztype and recompute constructor.
  2036                 clazztype = cdef.sym.type;
  2037                 Symbol sym = tree.constructor = rs.resolveConstructor(
  2038                     tree.pos(), localEnv, clazztype, argtypes, typeargtypes);
  2039                 Assert.check(sym.kind < AMBIGUOUS);
  2040                 tree.constructor = sym;
  2041                 tree.constructorType = checkId(tree,
  2042                     clazztype,
  2043                     tree.constructor,
  2044                     localEnv,
  2045                     new ResultInfo(VAL, newMethodTemplate(syms.voidType, argtypes, typeargtypes)));
  2048             if (tree.constructor != null && tree.constructor.kind == MTH)
  2049                 owntype = clazztype;
  2051         result = check(tree, owntype, VAL, resultInfo);
  2052         chk.validate(tree.typeargs, localEnv);
  2054     //where
  2055         void findDiamondIfNeeded(Env<AttrContext> env, JCNewClass tree, Type clazztype) {
  2056             if (tree.def == null &&
  2057                     !clazztype.isErroneous() &&
  2058                     clazztype.getTypeArguments().nonEmpty() &&
  2059                     findDiamonds) {
  2060                 JCTypeApply ta = (JCTypeApply)tree.clazz;
  2061                 List<JCExpression> prevTypeargs = ta.arguments;
  2062                 try {
  2063                     //create a 'fake' diamond AST node by removing type-argument trees
  2064                     ta.arguments = List.nil();
  2065                     ResultInfo findDiamondResult = new ResultInfo(VAL,
  2066                             resultInfo.checkContext.inferenceContext().free(resultInfo.pt) ? Type.noType : pt());
  2067                     Type inferred = deferredAttr.attribSpeculative(tree, env, findDiamondResult).type;
  2068                     if (!inferred.isErroneous() &&
  2069                         types.isAssignable(inferred, pt().hasTag(NONE) ? syms.objectType : pt(), types.noWarnings)) {
  2070                         String key = types.isSameType(clazztype, inferred) ?
  2071                             "diamond.redundant.args" :
  2072                             "diamond.redundant.args.1";
  2073                         log.warning(tree.clazz.pos(), key, clazztype, inferred);
  2075                 } finally {
  2076                     ta.arguments = prevTypeargs;
  2081             private void checkLambdaCandidate(JCNewClass tree, ClassSymbol csym, Type clazztype) {
  2082                 if (allowLambda &&
  2083                         identifyLambdaCandidate &&
  2084                         clazztype.hasTag(CLASS) &&
  2085                         !pt().hasTag(NONE) &&
  2086                         types.isFunctionalInterface(clazztype.tsym)) {
  2087                     Symbol descriptor = types.findDescriptorSymbol(clazztype.tsym);
  2088                     int count = 0;
  2089                     boolean found = false;
  2090                     for (Symbol sym : csym.members().getElements()) {
  2091                         if ((sym.flags() & SYNTHETIC) != 0 ||
  2092                                 sym.isConstructor()) continue;
  2093                         count++;
  2094                         if (sym.kind != MTH ||
  2095                                 !sym.name.equals(descriptor.name)) continue;
  2096                         Type mtype = types.memberType(clazztype, sym);
  2097                         if (types.overrideEquivalent(mtype, types.memberType(clazztype, descriptor))) {
  2098                             found = true;
  2101                     if (found && count == 1) {
  2102                         log.note(tree.def, "potential.lambda.found");
  2107     /** Make an attributed null check tree.
  2108      */
  2109     public JCExpression makeNullCheck(JCExpression arg) {
  2110         // optimization: X.this is never null; skip null check
  2111         Name name = TreeInfo.name(arg);
  2112         if (name == names._this || name == names._super) return arg;
  2114         JCTree.Tag optag = NULLCHK;
  2115         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
  2116         tree.operator = syms.nullcheck;
  2117         tree.type = arg.type;
  2118         return tree;
  2121     public void visitNewArray(JCNewArray tree) {
  2122         Type owntype = types.createErrorType(tree.type);
  2123         Env<AttrContext> localEnv = env.dup(tree);
  2124         Type elemtype;
  2125         if (tree.elemtype != null) {
  2126             elemtype = attribType(tree.elemtype, localEnv);
  2127             chk.validate(tree.elemtype, localEnv);
  2128             owntype = elemtype;
  2129             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
  2130                 attribExpr(l.head, localEnv, syms.intType);
  2131                 owntype = new ArrayType(owntype, syms.arrayClass);
  2133         } else {
  2134             // we are seeing an untyped aggregate { ... }
  2135             // this is allowed only if the prototype is an array
  2136             if (pt().hasTag(ARRAY)) {
  2137                 elemtype = types.elemtype(pt());
  2138             } else {
  2139                 if (!pt().hasTag(ERROR)) {
  2140                     log.error(tree.pos(), "illegal.initializer.for.type",
  2141                               pt());
  2143                 elemtype = types.createErrorType(pt());
  2146         if (tree.elems != null) {
  2147             attribExprs(tree.elems, localEnv, elemtype);
  2148             owntype = new ArrayType(elemtype, syms.arrayClass);
  2150         if (!types.isReifiable(elemtype))
  2151             log.error(tree.pos(), "generic.array.creation");
  2152         result = check(tree, owntype, VAL, resultInfo);
  2155     /*
  2156      * A lambda expression can only be attributed when a target-type is available.
  2157      * In addition, if the target-type is that of a functional interface whose
  2158      * descriptor contains inference variables in argument position the lambda expression
  2159      * is 'stuck' (see DeferredAttr).
  2160      */
  2161     @Override
  2162     public void visitLambda(final JCLambda that) {
  2163         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
  2164             if (pt().hasTag(NONE)) {
  2165                 //lambda only allowed in assignment or method invocation/cast context
  2166                 log.error(that.pos(), "unexpected.lambda");
  2168             result = that.type = types.createErrorType(pt());
  2169             return;
  2171         //create an environment for attribution of the lambda expression
  2172         final Env<AttrContext> localEnv = lambdaEnv(that, env);
  2173         boolean needsRecovery =
  2174                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
  2175         try {
  2176             List<Type> explicitParamTypes = null;
  2177             if (TreeInfo.isExplicitLambda(that)) {
  2178                 //attribute lambda parameters
  2179                 attribStats(that.params, localEnv);
  2180                 explicitParamTypes = TreeInfo.types(that.params);
  2183             Type target;
  2184             Type lambdaType;
  2185             if (pt() != Type.recoveryType) {
  2186                 target = infer.instantiateFunctionalInterface(that, checkIntersectionTarget(that, resultInfo), explicitParamTypes, resultInfo.checkContext);
  2187                 lambdaType = types.findDescriptorType(target);
  2188                 chk.checkFunctionalInterface(that, target);
  2189             } else {
  2190                 target = Type.recoveryType;
  2191                 lambdaType = fallbackDescriptorType(that);
  2194             if (lambdaType.hasTag(FORALL)) {
  2195                 //lambda expression target desc cannot be a generic method
  2196                 resultInfo.checkContext.report(that, diags.fragment("invalid.generic.lambda.target",
  2197                         lambdaType, kindName(target.tsym), target.tsym));
  2198                 result = that.type = types.createErrorType(pt());
  2199                 return;
  2202             if (!TreeInfo.isExplicitLambda(that)) {
  2203                 //add param type info in the AST
  2204                 List<Type> actuals = lambdaType.getParameterTypes();
  2205                 List<JCVariableDecl> params = that.params;
  2207                 boolean arityMismatch = false;
  2209                 while (params.nonEmpty()) {
  2210                     if (actuals.isEmpty()) {
  2211                         //not enough actuals to perform lambda parameter inference
  2212                         arityMismatch = true;
  2214                     //reset previously set info
  2215                     Type argType = arityMismatch ?
  2216                             syms.errType :
  2217                             actuals.head;
  2218                     params.head.vartype = make.Type(argType);
  2219                     params.head.sym = null;
  2220                     actuals = actuals.isEmpty() ?
  2221                             actuals :
  2222                             actuals.tail;
  2223                     params = params.tail;
  2226                 //attribute lambda parameters
  2227                 attribStats(that.params, localEnv);
  2229                 if (arityMismatch) {
  2230                     resultInfo.checkContext.report(that, diags.fragment("incompatible.arg.types.in.lambda"));
  2231                         result = that.type = types.createErrorType(target);
  2232                         return;
  2236             //from this point on, no recovery is needed; if we are in assignment context
  2237             //we will be able to attribute the whole lambda body, regardless of errors;
  2238             //if we are in a 'check' method context, and the lambda is not compatible
  2239             //with the target-type, it will be recovered anyway in Attr.checkId
  2240             needsRecovery = false;
  2242             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
  2243                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
  2244                     new FunctionalReturnContext(resultInfo.checkContext);
  2246             ResultInfo bodyResultInfo = lambdaType.getReturnType() == Type.recoveryType ?
  2247                 recoveryInfo :
  2248                 new ResultInfo(VAL, lambdaType.getReturnType(), funcContext);
  2249             localEnv.info.returnResult = bodyResultInfo;
  2251             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
  2252                 attribTree(that.getBody(), localEnv, bodyResultInfo);
  2253             } else {
  2254                 JCBlock body = (JCBlock)that.body;
  2255                 attribStats(body.stats, localEnv);
  2258             result = check(that, target, VAL, resultInfo);
  2260             boolean isSpeculativeRound =
  2261                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
  2263             postAttr(that);
  2264             flow.analyzeLambda(env, that, make, isSpeculativeRound);
  2266             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext, isSpeculativeRound);
  2268             if (!isSpeculativeRound) {
  2269                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, target);
  2271             result = check(that, target, VAL, resultInfo);
  2272         } catch (Types.FunctionDescriptorLookupError ex) {
  2273             JCDiagnostic cause = ex.getDiagnostic();
  2274             resultInfo.checkContext.report(that, cause);
  2275             result = that.type = types.createErrorType(pt());
  2276             return;
  2277         } finally {
  2278             localEnv.info.scope.leave();
  2279             if (needsRecovery) {
  2280                 attribTree(that, env, recoveryInfo);
  2285     private Type checkIntersectionTarget(DiagnosticPosition pos, ResultInfo resultInfo) {
  2286         Type pt = resultInfo.pt;
  2287         if (pt != Type.recoveryType && pt.isCompound()) {
  2288             IntersectionClassType ict = (IntersectionClassType)pt;
  2289             List<Type> bounds = ict.allInterfaces ?
  2290                     ict.getComponents().tail :
  2291                     ict.getComponents();
  2292             types.findDescriptorType(bounds.head); //propagate exception outwards!
  2293             for (Type bound : bounds.tail) {
  2294                 if (!types.isMarkerInterface(bound)) {
  2295                     resultInfo.checkContext.report(pos, diags.fragment("secondary.bound.must.be.marker.intf", bound));
  2298             //for now (translation doesn't support intersection types)
  2299             return bounds.head;
  2300         } else {
  2301             return pt;
  2304     //where
  2305         private Type fallbackDescriptorType(JCExpression tree) {
  2306             switch (tree.getTag()) {
  2307                 case LAMBDA:
  2308                     JCLambda lambda = (JCLambda)tree;
  2309                     List<Type> argtypes = List.nil();
  2310                     for (JCVariableDecl param : lambda.params) {
  2311                         argtypes = param.vartype != null ?
  2312                                 argtypes.append(param.vartype.type) :
  2313                                 argtypes.append(syms.errType);
  2315                     return new MethodType(argtypes, Type.recoveryType, List.<Type>nil(), syms.methodClass);
  2316                 case REFERENCE:
  2317                     return new MethodType(List.<Type>nil(), Type.recoveryType, List.<Type>nil(), syms.methodClass);
  2318                 default:
  2319                     Assert.error("Cannot get here!");
  2321             return null;
  2324         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env, final InferenceContext inferenceContext, final Type... ts) {
  2325             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
  2328         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env, final InferenceContext inferenceContext, final List<Type> ts) {
  2329             if (inferenceContext.free(ts)) {
  2330                 inferenceContext.addFreeTypeListener(ts, new FreeTypeListener() {
  2331                     @Override
  2332                     public void typesInferred(InferenceContext inferenceContext) {
  2333                         checkAccessibleTypes(pos, env, inferenceContext, inferenceContext.asInstTypes(ts, types));
  2335                 });
  2336             } else {
  2337                 for (Type t : ts) {
  2338                     rs.checkAccessibleType(env, t);
  2343         /**
  2344          * Lambda/method reference have a special check context that ensures
  2345          * that i.e. a lambda return type is compatible with the expected
  2346          * type according to both the inherited context and the assignment
  2347          * context.
  2348          */
  2349         class FunctionalReturnContext extends Check.NestedCheckContext {
  2351             FunctionalReturnContext(CheckContext enclosingContext) {
  2352                 super(enclosingContext);
  2355             @Override
  2356             public boolean compatible(Type found, Type req, Warner warn) {
  2357                 //return type must be compatible in both current context and assignment context
  2358                 return types.isAssignable(found, inferenceContext().asFree(req, types), warn) &&
  2359                         super.compatible(found, req, warn);
  2361             @Override
  2362             public void report(DiagnosticPosition pos, JCDiagnostic details) {
  2363                 enclosingContext.report(pos, diags.fragment("incompatible.ret.type.in.lambda", details));
  2367         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
  2369             JCExpression expr;
  2371             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
  2372                 super(enclosingContext);
  2373                 this.expr = expr;
  2376             @Override
  2377             public boolean compatible(Type found, Type req, Warner warn) {
  2378                 //a void return is compatible with an expression statement lambda
  2379                 return TreeInfo.isExpressionStatement(expr) && req.hasTag(VOID) ||
  2380                         super.compatible(found, req, warn);
  2384         /**
  2385         * Lambda compatibility. Check that given return types, thrown types, parameter types
  2386         * are compatible with the expected functional interface descriptor. This means that:
  2387         * (i) parameter types must be identical to those of the target descriptor; (ii) return
  2388         * types must be compatible with the return type of the expected descriptor;
  2389         * (iii) thrown types must be 'included' in the thrown types list of the expected
  2390         * descriptor.
  2391         */
  2392         private void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext, boolean speculativeAttr) {
  2393             Type returnType = checkContext.inferenceContext().asFree(descriptor.getReturnType(), types);
  2395             //return values have already been checked - but if lambda has no return
  2396             //values, we must ensure that void/value compatibility is correct;
  2397             //this amounts at checking that, if a lambda body can complete normally,
  2398             //the descriptor's return type must be void
  2399             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
  2400                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
  2401                 checkContext.report(tree, diags.fragment("incompatible.ret.type.in.lambda",
  2402                         diags.fragment("missing.ret.val", returnType)));
  2405             List<Type> argTypes = checkContext.inferenceContext().asFree(descriptor.getParameterTypes(), types);
  2406             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
  2407                 checkContext.report(tree, diags.fragment("incompatible.arg.types.in.lambda"));
  2410             if (!speculativeAttr) {
  2411                 List<Type> thrownTypes = checkContext.inferenceContext().asFree(descriptor.getThrownTypes(), types);
  2412                 if (chk.unhandled(tree.inferredThrownTypes == null ? List.<Type>nil() : tree.inferredThrownTypes, thrownTypes).nonEmpty()) {
  2413                     log.error(tree, "incompatible.thrown.types.in.lambda", tree.inferredThrownTypes);
  2418         private Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
  2419             Env<AttrContext> lambdaEnv;
  2420             Symbol owner = env.info.scope.owner;
  2421             if (owner.kind == VAR && owner.owner.kind == TYP) {
  2422                 //field initializer
  2423                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared()));
  2424                 lambdaEnv.info.scope.owner =
  2425                     new MethodSymbol(0, names.empty, null,
  2426                                      env.info.scope.owner);
  2427             } else {
  2428                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
  2430             return lambdaEnv;
  2433     @Override
  2434     public void visitReference(final JCMemberReference that) {
  2435         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
  2436             if (pt().hasTag(NONE)) {
  2437                 //method reference only allowed in assignment or method invocation/cast context
  2438                 log.error(that.pos(), "unexpected.mref");
  2440             result = that.type = types.createErrorType(pt());
  2441             return;
  2443         final Env<AttrContext> localEnv = env.dup(that);
  2444         try {
  2445             //attribute member reference qualifier - if this is a constructor
  2446             //reference, the expected kind must be a type
  2447             Type exprType = attribTree(that.expr,
  2448                     env, new ResultInfo(that.getMode() == ReferenceMode.INVOKE ? VAL | TYP : TYP, Type.noType));
  2450             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
  2451                 exprType = chk.checkConstructorRefType(that.expr, exprType);
  2454             if (exprType.isErroneous()) {
  2455                 //if the qualifier expression contains problems,
  2456                 //give up atttribution of method reference
  2457                 result = that.type = exprType;
  2458                 return;
  2461             if (TreeInfo.isStaticSelector(that.expr, names) &&
  2462                     (that.getMode() != ReferenceMode.NEW || !that.expr.type.isRaw())) {
  2463                 //if the qualifier is a type, validate it
  2464                 chk.validate(that.expr, env);
  2467             //attrib type-arguments
  2468             List<Type> typeargtypes = List.nil();
  2469             if (that.typeargs != null) {
  2470                 typeargtypes = attribTypes(that.typeargs, localEnv);
  2473             Type target;
  2474             Type desc;
  2475             if (pt() != Type.recoveryType) {
  2476                 target = infer.instantiateFunctionalInterface(that, checkIntersectionTarget(that, resultInfo), null, resultInfo.checkContext);
  2477                 desc = types.findDescriptorType(target);
  2478                 chk.checkFunctionalInterface(that, target);
  2479             } else {
  2480                 target = Type.recoveryType;
  2481                 desc = fallbackDescriptorType(that);
  2484             List<Type> argtypes = desc.getParameterTypes();
  2486             boolean allowBoxing =
  2487                     resultInfo.checkContext.deferredAttrContext().phase.isBoxingRequired();
  2488             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = rs.resolveMemberReference(that.pos(), localEnv, that,
  2489                     that.expr.type, that.name, argtypes, typeargtypes, allowBoxing);
  2491             Symbol refSym = refResult.fst;
  2492             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
  2494             if (refSym.kind != MTH) {
  2495                 boolean targetError;
  2496                 switch (refSym.kind) {
  2497                     case ABSENT_MTH:
  2498                         targetError = false;
  2499                         break;
  2500                     case WRONG_MTH:
  2501                     case WRONG_MTHS:
  2502                     case AMBIGUOUS:
  2503                     case HIDDEN:
  2504                     case STATICERR:
  2505                     case MISSING_ENCL:
  2506                         targetError = true;
  2507                         break;
  2508                     default:
  2509                         Assert.error("unexpected result kind " + refSym.kind);
  2510                         targetError = false;
  2513                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym).getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
  2514                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
  2516                 JCDiagnostic.DiagnosticType diagKind = targetError ?
  2517                         JCDiagnostic.DiagnosticType.FRAGMENT : JCDiagnostic.DiagnosticType.ERROR;
  2519                 JCDiagnostic diag = diags.create(diagKind, log.currentSource(), that,
  2520                         "invalid.mref", Kinds.kindName(that.getMode()), detailsDiag);
  2522                 if (targetError && target == Type.recoveryType) {
  2523                     //a target error doesn't make sense during recovery stage
  2524                     //as we don't know what actual parameter types are
  2525                     result = that.type = target;
  2526                     return;
  2527                 } else {
  2528                     if (targetError) {
  2529                         resultInfo.checkContext.report(that, diag);
  2530                     } else {
  2531                         log.report(diag);
  2533                     result = that.type = types.createErrorType(target);
  2534                     return;
  2538             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
  2539                 if (refSym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
  2540                         exprType.getTypeArguments().nonEmpty()) {
  2541                     //static ref with class type-args
  2542                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2543                             diags.fragment("static.mref.with.targs"));
  2544                     result = that.type = types.createErrorType(target);
  2545                     return;
  2548                 if (refSym.isStatic() && !TreeInfo.isStaticSelector(that.expr, names) &&
  2549                         !lookupHelper.referenceKind(refSym).isUnbound()) {
  2550                     //no static bound mrefs
  2551                     log.error(that.expr.pos(), "invalid.mref", Kinds.kindName(that.getMode()),
  2552                             diags.fragment("static.bound.mref"));
  2553                     result = that.type = types.createErrorType(target);
  2554                     return;
  2558             if (desc.getReturnType() == Type.recoveryType) {
  2559                 // stop here
  2560                 result = that.type = target;
  2561                 return;
  2564             that.sym = refSym.baseSymbol();
  2565             that.kind = lookupHelper.referenceKind(that.sym);
  2567             ResultInfo checkInfo =
  2568                     resultInfo.dup(newMethodTemplate(
  2569                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
  2570                         lookupHelper.argtypes,
  2571                         typeargtypes));
  2573             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
  2575             if (!refType.isErroneous()) {
  2576                 refType = types.createMethodTypeWithReturn(refType,
  2577                         adjustMethodReturnType(lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
  2580             //go ahead with standard method reference compatibility check - note that param check
  2581             //is a no-op (as this has been taken care during method applicability)
  2582             boolean isSpeculativeRound =
  2583                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
  2584             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
  2585             if (!isSpeculativeRound) {
  2586                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, target);
  2588             result = check(that, target, VAL, resultInfo);
  2589         } catch (Types.FunctionDescriptorLookupError ex) {
  2590             JCDiagnostic cause = ex.getDiagnostic();
  2591             resultInfo.checkContext.report(that, cause);
  2592             result = that.type = types.createErrorType(pt());
  2593             return;
  2597     @SuppressWarnings("fallthrough")
  2598     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
  2599         Type returnType = checkContext.inferenceContext().asFree(descriptor.getReturnType(), types);
  2601         Type resType;
  2602         switch (tree.getMode()) {
  2603             case NEW:
  2604                 if (!tree.expr.type.isRaw()) {
  2605                     resType = tree.expr.type;
  2606                     break;
  2608             default:
  2609                 resType = refType.getReturnType();
  2612         Type incompatibleReturnType = resType;
  2614         if (returnType.hasTag(VOID)) {
  2615             incompatibleReturnType = null;
  2618         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
  2619             if (resType.isErroneous() ||
  2620                     new FunctionalReturnContext(checkContext).compatible(resType, returnType, types.noWarnings)) {
  2621                 incompatibleReturnType = null;
  2625         if (incompatibleReturnType != null) {
  2626             checkContext.report(tree, diags.fragment("incompatible.ret.type.in.mref",
  2627                     diags.fragment("inconvertible.types", resType, descriptor.getReturnType())));
  2630         if (!speculativeAttr) {
  2631             List<Type> thrownTypes = checkContext.inferenceContext().asFree(descriptor.getThrownTypes(), types);
  2632             if (chk.unhandled(refType.getThrownTypes(), thrownTypes).nonEmpty()) {
  2633                 log.error(tree, "incompatible.thrown.types.in.mref", refType.getThrownTypes());
  2638     public void visitParens(JCParens tree) {
  2639         Type owntype = attribTree(tree.expr, env, resultInfo);
  2640         result = check(tree, owntype, pkind(), resultInfo);
  2641         Symbol sym = TreeInfo.symbol(tree);
  2642         if (sym != null && (sym.kind&(TYP|PCK)) != 0)
  2643             log.error(tree.pos(), "illegal.start.of.type");
  2646     public void visitAssign(JCAssign tree) {
  2647         Type owntype = attribTree(tree.lhs, env.dup(tree), varInfo);
  2648         Type capturedType = capture(owntype);
  2649         attribExpr(tree.rhs, env, owntype);
  2650         result = check(tree, capturedType, VAL, resultInfo);
  2653     public void visitAssignop(JCAssignOp tree) {
  2654         // Attribute arguments.
  2655         Type owntype = attribTree(tree.lhs, env, varInfo);
  2656         Type operand = attribExpr(tree.rhs, env);
  2657         // Find operator.
  2658         Symbol operator = tree.operator = rs.resolveBinaryOperator(
  2659             tree.pos(), tree.getTag().noAssignOp(), env,
  2660             owntype, operand);
  2662         if (operator.kind == MTH &&
  2663                 !owntype.isErroneous() &&
  2664                 !operand.isErroneous()) {
  2665             chk.checkOperator(tree.pos(),
  2666                               (OperatorSymbol)operator,
  2667                               tree.getTag().noAssignOp(),
  2668                               owntype,
  2669                               operand);
  2670             chk.checkDivZero(tree.rhs.pos(), operator, operand);
  2671             chk.checkCastable(tree.rhs.pos(),
  2672                               operator.type.getReturnType(),
  2673                               owntype);
  2675         result = check(tree, owntype, VAL, resultInfo);
  2678     public void visitUnary(JCUnary tree) {
  2679         // Attribute arguments.
  2680         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
  2681             ? attribTree(tree.arg, env, varInfo)
  2682             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
  2684         // Find operator.
  2685         Symbol operator = tree.operator =
  2686             rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype);
  2688         Type owntype = types.createErrorType(tree.type);
  2689         if (operator.kind == MTH &&
  2690                 !argtype.isErroneous()) {
  2691             owntype = (tree.getTag().isIncOrDecUnaryOp())
  2692                 ? tree.arg.type
  2693                 : operator.type.getReturnType();
  2694             int opc = ((OperatorSymbol)operator).opcode;
  2696             // If the argument is constant, fold it.
  2697             if (argtype.constValue() != null) {
  2698                 Type ctype = cfolder.fold1(opc, argtype);
  2699                 if (ctype != null) {
  2700                     owntype = cfolder.coerce(ctype, owntype);
  2702                     // Remove constant types from arguments to
  2703                     // conserve space. The parser will fold concatenations
  2704                     // of string literals; the code here also
  2705                     // gets rid of intermediate results when some of the
  2706                     // operands are constant identifiers.
  2707                     if (tree.arg.type.tsym == syms.stringType.tsym) {
  2708                         tree.arg.type = syms.stringType;
  2713         result = check(tree, owntype, VAL, resultInfo);
  2716     public void visitBinary(JCBinary tree) {
  2717         // Attribute arguments.
  2718         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
  2719         Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));
  2721         // Find operator.
  2722         Symbol operator = tree.operator =
  2723             rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right);
  2725         Type owntype = types.createErrorType(tree.type);
  2726         if (operator.kind == MTH &&
  2727                 !left.isErroneous() &&
  2728                 !right.isErroneous()) {
  2729             owntype = operator.type.getReturnType();
  2730             int opc = chk.checkOperator(tree.lhs.pos(),
  2731                                         (OperatorSymbol)operator,
  2732                                         tree.getTag(),
  2733                                         left,
  2734                                         right);
  2736             // If both arguments are constants, fold them.
  2737             if (left.constValue() != null && right.constValue() != null) {
  2738                 Type ctype = cfolder.fold2(opc, left, right);
  2739                 if (ctype != null) {
  2740                     owntype = cfolder.coerce(ctype, owntype);
  2742                     // Remove constant types from arguments to
  2743                     // conserve space. The parser will fold concatenations
  2744                     // of string literals; the code here also
  2745                     // gets rid of intermediate results when some of the
  2746                     // operands are constant identifiers.
  2747                     if (tree.lhs.type.tsym == syms.stringType.tsym) {
  2748                         tree.lhs.type = syms.stringType;
  2750                     if (tree.rhs.type.tsym == syms.stringType.tsym) {
  2751                         tree.rhs.type = syms.stringType;
  2756             // Check that argument types of a reference ==, != are
  2757             // castable to each other, (JLS???).
  2758             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
  2759                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
  2760                     log.error(tree.pos(), "incomparable.types", left, right);
  2764             chk.checkDivZero(tree.rhs.pos(), operator, right);
  2766         result = check(tree, owntype, VAL, resultInfo);
  2769     public void visitTypeCast(final JCTypeCast tree) {
  2770         Type clazztype = attribType(tree.clazz, env);
  2771         chk.validate(tree.clazz, env, false);
  2772         //a fresh environment is required for 292 inference to work properly ---
  2773         //see Infer.instantiatePolymorphicSignatureInstance()
  2774         Env<AttrContext> localEnv = env.dup(tree);
  2775         //should we propagate the target type?
  2776         final ResultInfo castInfo;
  2777         final boolean isPoly = TreeInfo.isPoly(tree.expr, tree);
  2778         if (isPoly) {
  2779             //expression is a poly - we need to propagate target type info
  2780             castInfo = new ResultInfo(VAL, clazztype, new Check.NestedCheckContext(resultInfo.checkContext) {
  2781                 @Override
  2782                 public boolean compatible(Type found, Type req, Warner warn) {
  2783                     return types.isCastable(found, req, warn);
  2785             });
  2786         } else {
  2787             //standalone cast - target-type info is not propagated
  2788             castInfo = unknownExprInfo;
  2790         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
  2791         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
  2792         if (exprtype.constValue() != null)
  2793             owntype = cfolder.coerce(exprtype, owntype);
  2794         result = check(tree, capture(owntype), VAL, resultInfo);
  2795         if (!isPoly)
  2796             chk.checkRedundantCast(localEnv, tree);
  2799     public void visitTypeTest(JCInstanceOf tree) {
  2800         Type exprtype = chk.checkNullOrRefType(
  2801             tree.expr.pos(), attribExpr(tree.expr, env));
  2802         Type clazztype = chk.checkReifiableReferenceType(
  2803             tree.clazz.pos(), attribType(tree.clazz, env));
  2804         chk.validate(tree.clazz, env, false);
  2805         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
  2806         result = check(tree, syms.booleanType, VAL, resultInfo);
  2809     public void visitIndexed(JCArrayAccess tree) {
  2810         Type owntype = types.createErrorType(tree.type);
  2811         Type atype = attribExpr(tree.indexed, env);
  2812         attribExpr(tree.index, env, syms.intType);
  2813         if (types.isArray(atype))
  2814             owntype = types.elemtype(atype);
  2815         else if (!atype.hasTag(ERROR))
  2816             log.error(tree.pos(), "array.req.but.found", atype);
  2817         if ((pkind() & VAR) == 0) owntype = capture(owntype);
  2818         result = check(tree, owntype, VAR, resultInfo);
  2821     public void visitIdent(JCIdent tree) {
  2822         Symbol sym;
  2824         // Find symbol
  2825         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
  2826             // If we are looking for a method, the prototype `pt' will be a
  2827             // method type with the type of the call's arguments as parameters.
  2828             env.info.pendingResolutionPhase = null;
  2829             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
  2830         } else if (tree.sym != null && tree.sym.kind != VAR) {
  2831             sym = tree.sym;
  2832         } else {
  2833             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
  2835         tree.sym = sym;
  2837         // (1) Also find the environment current for the class where
  2838         //     sym is defined (`symEnv').
  2839         // Only for pre-tiger versions (1.4 and earlier):
  2840         // (2) Also determine whether we access symbol out of an anonymous
  2841         //     class in a this or super call.  This is illegal for instance
  2842         //     members since such classes don't carry a this$n link.
  2843         //     (`noOuterThisPath').
  2844         Env<AttrContext> symEnv = env;
  2845         boolean noOuterThisPath = false;
  2846         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
  2847             (sym.kind & (VAR | MTH | TYP)) != 0 &&
  2848             sym.owner.kind == TYP &&
  2849             tree.name != names._this && tree.name != names._super) {
  2851             // Find environment in which identifier is defined.
  2852             while (symEnv.outer != null &&
  2853                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
  2854                 if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
  2855                     noOuterThisPath = !allowAnonOuterThis;
  2856                 symEnv = symEnv.outer;
  2860         // If symbol is a variable, ...
  2861         if (sym.kind == VAR) {
  2862             VarSymbol v = (VarSymbol)sym;
  2864             // ..., evaluate its initializer, if it has one, and check for
  2865             // illegal forward reference.
  2866             checkInit(tree, env, v, false);
  2868             // If we are expecting a variable (as opposed to a value), check
  2869             // that the variable is assignable in the current environment.
  2870             if (pkind() == VAR)
  2871                 checkAssignable(tree.pos(), v, null, env);
  2874         // In a constructor body,
  2875         // if symbol is a field or instance method, check that it is
  2876         // not accessed before the supertype constructor is called.
  2877         if ((symEnv.info.isSelfCall || noOuterThisPath) &&
  2878             (sym.kind & (VAR | MTH)) != 0 &&
  2879             sym.owner.kind == TYP &&
  2880             (sym.flags() & STATIC) == 0) {
  2881             chk.earlyRefError(tree.pos(), sym.kind == VAR ? sym : thisSym(tree.pos(), env));
  2883         Env<AttrContext> env1 = env;
  2884         if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
  2885             // If the found symbol is inaccessible, then it is
  2886             // accessed through an enclosing instance.  Locate this
  2887             // enclosing instance:
  2888             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
  2889                 env1 = env1.outer;
  2891         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
  2894     public void visitSelect(JCFieldAccess tree) {
  2895         // Determine the expected kind of the qualifier expression.
  2896         int skind = 0;
  2897         if (tree.name == names._this || tree.name == names._super ||
  2898             tree.name == names._class)
  2900             skind = TYP;
  2901         } else {
  2902             if ((pkind() & PCK) != 0) skind = skind | PCK;
  2903             if ((pkind() & TYP) != 0) skind = skind | TYP | PCK;
  2904             if ((pkind() & (VAL | MTH)) != 0) skind = skind | VAL | TYP;
  2907         // Attribute the qualifier expression, and determine its symbol (if any).
  2908         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Infer.anyPoly));
  2909         if ((pkind() & (PCK | TYP)) == 0)
  2910             site = capture(site); // Capture field access
  2912         // don't allow T.class T[].class, etc
  2913         if (skind == TYP) {
  2914             Type elt = site;
  2915             while (elt.hasTag(ARRAY))
  2916                 elt = ((ArrayType)elt).elemtype;
  2917             if (elt.hasTag(TYPEVAR)) {
  2918                 log.error(tree.pos(), "type.var.cant.be.deref");
  2919                 result = types.createErrorType(tree.type);
  2920                 return;
  2924         // If qualifier symbol is a type or `super', assert `selectSuper'
  2925         // for the selection. This is relevant for determining whether
  2926         // protected symbols are accessible.
  2927         Symbol sitesym = TreeInfo.symbol(tree.selected);
  2928         boolean selectSuperPrev = env.info.selectSuper;
  2929         env.info.selectSuper =
  2930             sitesym != null &&
  2931             sitesym.name == names._super;
  2933         // Determine the symbol represented by the selection.
  2934         env.info.pendingResolutionPhase = null;
  2935         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
  2936         if (sym.exists() && !isType(sym) && (pkind() & (PCK | TYP)) != 0) {
  2937             site = capture(site);
  2938             sym = selectSym(tree, sitesym, site, env, resultInfo);
  2940         boolean varArgs = env.info.lastResolveVarargs();
  2941         tree.sym = sym;
  2943         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
  2944             while (site.hasTag(TYPEVAR)) site = site.getUpperBound();
  2945             site = capture(site);
  2948         // If that symbol is a variable, ...
  2949         if (sym.kind == VAR) {
  2950             VarSymbol v = (VarSymbol)sym;
  2952             // ..., evaluate its initializer, if it has one, and check for
  2953             // illegal forward reference.
  2954             checkInit(tree, env, v, true);
  2956             // If we are expecting a variable (as opposed to a value), check
  2957             // that the variable is assignable in the current environment.
  2958             if (pkind() == VAR)
  2959                 checkAssignable(tree.pos(), v, tree.selected, env);
  2962         if (sitesym != null &&
  2963                 sitesym.kind == VAR &&
  2964                 ((VarSymbol)sitesym).isResourceVariable() &&
  2965                 sym.kind == MTH &&
  2966                 sym.name.equals(names.close) &&
  2967                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
  2968                 env.info.lint.isEnabled(LintCategory.TRY)) {
  2969             log.warning(LintCategory.TRY, tree, "try.explicit.close.call");
  2972         // Disallow selecting a type from an expression
  2973         if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) {
  2974             tree.type = check(tree.selected, pt(),
  2975                               sitesym == null ? VAL : sitesym.kind, new ResultInfo(TYP|PCK, pt()));
  2978         if (isType(sitesym)) {
  2979             if (sym.name == names._this) {
  2980                 // If `C' is the currently compiled class, check that
  2981                 // C.this' does not appear in a call to a super(...)
  2982                 if (env.info.isSelfCall &&
  2983                     site.tsym == env.enclClass.sym) {
  2984                     chk.earlyRefError(tree.pos(), sym);
  2986             } else {
  2987                 // Check if type-qualified fields or methods are static (JLS)
  2988                 if ((sym.flags() & STATIC) == 0 &&
  2989                     !env.next.tree.hasTag(REFERENCE) &&
  2990                     sym.name != names._super &&
  2991                     (sym.kind == VAR || sym.kind == MTH)) {
  2992                     rs.accessBase(rs.new StaticError(sym),
  2993                               tree.pos(), site, sym.name, true);
  2996         } else if (sym.kind != ERR && (sym.flags() & STATIC) != 0 && sym.name != names._class) {
  2997             // If the qualified item is not a type and the selected item is static, report
  2998             // a warning. Make allowance for the class of an array type e.g. Object[].class)
  2999             chk.warnStatic(tree, "static.not.qualified.by.type", Kinds.kindName(sym.kind), sym.owner);
  3002         // If we are selecting an instance member via a `super', ...
  3003         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
  3005             // Check that super-qualified symbols are not abstract (JLS)
  3006             rs.checkNonAbstract(tree.pos(), sym);
  3008             if (site.isRaw()) {
  3009                 // Determine argument types for site.
  3010                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
  3011                 if (site1 != null) site = site1;
  3015         env.info.selectSuper = selectSuperPrev;
  3016         result = checkId(tree, site, sym, env, resultInfo);
  3018     //where
  3019         /** Determine symbol referenced by a Select expression,
  3021          *  @param tree   The select tree.
  3022          *  @param site   The type of the selected expression,
  3023          *  @param env    The current environment.
  3024          *  @param resultInfo The current result.
  3025          */
  3026         private Symbol selectSym(JCFieldAccess tree,
  3027                                  Symbol location,
  3028                                  Type site,
  3029                                  Env<AttrContext> env,
  3030                                  ResultInfo resultInfo) {
  3031             DiagnosticPosition pos = tree.pos();
  3032             Name name = tree.name;
  3033             switch (site.getTag()) {
  3034             case PACKAGE:
  3035                 return rs.accessBase(
  3036                     rs.findIdentInPackage(env, site.tsym, name, resultInfo.pkind),
  3037                     pos, location, site, name, true);
  3038             case ARRAY:
  3039             case CLASS:
  3040                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
  3041                     return rs.resolveQualifiedMethod(
  3042                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
  3043                 } else if (name == names._this || name == names._super) {
  3044                     return rs.resolveSelf(pos, env, site.tsym, name);
  3045                 } else if (name == names._class) {
  3046                     // In this case, we have already made sure in
  3047                     // visitSelect that qualifier expression is a type.
  3048                     Type t = syms.classType;
  3049                     List<Type> typeargs = allowGenerics
  3050                         ? List.of(types.erasure(site))
  3051                         : List.<Type>nil();
  3052                     t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
  3053                     return new VarSymbol(
  3054                         STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
  3055                 } else {
  3056                     // We are seeing a plain identifier as selector.
  3057                     Symbol sym = rs.findIdentInType(env, site, name, resultInfo.pkind);
  3058                     if ((resultInfo.pkind & ERRONEOUS) == 0)
  3059                         sym = rs.accessBase(sym, pos, location, site, name, true);
  3060                     return sym;
  3062             case WILDCARD:
  3063                 throw new AssertionError(tree);
  3064             case TYPEVAR:
  3065                 // Normally, site.getUpperBound() shouldn't be null.
  3066                 // It should only happen during memberEnter/attribBase
  3067                 // when determining the super type which *must* beac
  3068                 // done before attributing the type variables.  In
  3069                 // other words, we are seeing this illegal program:
  3070                 // class B<T> extends A<T.foo> {}
  3071                 Symbol sym = (site.getUpperBound() != null)
  3072                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
  3073                     : null;
  3074                 if (sym == null) {
  3075                     log.error(pos, "type.var.cant.be.deref");
  3076                     return syms.errSymbol;
  3077                 } else {
  3078                     Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
  3079                         rs.new AccessError(env, site, sym) :
  3080                                 sym;
  3081                     rs.accessBase(sym2, pos, location, site, name, true);
  3082                     return sym;
  3084             case ERROR:
  3085                 // preserve identifier names through errors
  3086                 return types.createErrorType(name, site.tsym, site).tsym;
  3087             default:
  3088                 // The qualifier expression is of a primitive type -- only
  3089                 // .class is allowed for these.
  3090                 if (name == names._class) {
  3091                     // In this case, we have already made sure in Select that
  3092                     // qualifier expression is a type.
  3093                     Type t = syms.classType;
  3094                     Type arg = types.boxedClass(site).type;
  3095                     t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
  3096                     return new VarSymbol(
  3097                         STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
  3098                 } else {
  3099                     log.error(pos, "cant.deref", site);
  3100                     return syms.errSymbol;
  3105         /** Determine type of identifier or select expression and check that
  3106          *  (1) the referenced symbol is not deprecated
  3107          *  (2) the symbol's type is safe (@see checkSafe)
  3108          *  (3) if symbol is a variable, check that its type and kind are
  3109          *      compatible with the prototype and protokind.
  3110          *  (4) if symbol is an instance field of a raw type,
  3111          *      which is being assigned to, issue an unchecked warning if its
  3112          *      type changes under erasure.
  3113          *  (5) if symbol is an instance method of a raw type, issue an
  3114          *      unchecked warning if its argument types change under erasure.
  3115          *  If checks succeed:
  3116          *    If symbol is a constant, return its constant type
  3117          *    else if symbol is a method, return its result type
  3118          *    otherwise return its type.
  3119          *  Otherwise return errType.
  3121          *  @param tree       The syntax tree representing the identifier
  3122          *  @param site       If this is a select, the type of the selected
  3123          *                    expression, otherwise the type of the current class.
  3124          *  @param sym        The symbol representing the identifier.
  3125          *  @param env        The current environment.
  3126          *  @param resultInfo    The expected result
  3127          */
  3128         Type checkId(JCTree tree,
  3129                      Type site,
  3130                      Symbol sym,
  3131                      Env<AttrContext> env,
  3132                      ResultInfo resultInfo) {
  3133             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
  3134                     checkMethodId(tree, site, sym, env, resultInfo) :
  3135                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
  3138         Type checkMethodId(JCTree tree,
  3139                      Type site,
  3140                      Symbol sym,
  3141                      Env<AttrContext> env,
  3142                      ResultInfo resultInfo) {
  3143             boolean isPolymorhicSignature =
  3144                 sym.kind == MTH && ((MethodSymbol)sym.baseSymbol()).isSignaturePolymorphic(types);
  3145             return isPolymorhicSignature ?
  3146                     checkSigPolyMethodId(tree, site, sym, env, resultInfo) :
  3147                     checkMethodIdInternal(tree, site, sym, env, resultInfo);
  3150         Type checkSigPolyMethodId(JCTree tree,
  3151                      Type site,
  3152                      Symbol sym,
  3153                      Env<AttrContext> env,
  3154                      ResultInfo resultInfo) {
  3155             //recover original symbol for signature polymorphic methods
  3156             checkMethodIdInternal(tree, site, sym.baseSymbol(), env, resultInfo);
  3157             env.info.pendingResolutionPhase = Resolve.MethodResolutionPhase.BASIC;
  3158             return sym.type;
  3161         Type checkMethodIdInternal(JCTree tree,
  3162                      Type site,
  3163                      Symbol sym,
  3164                      Env<AttrContext> env,
  3165                      ResultInfo resultInfo) {
  3166             Type pt = resultInfo.pt.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, sym, env.info.pendingResolutionPhase));
  3167             Type owntype = checkIdInternal(tree, site, sym, pt, env, resultInfo);
  3168             resultInfo.pt.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
  3169             return owntype;
  3172         Type checkIdInternal(JCTree tree,
  3173                      Type site,
  3174                      Symbol sym,
  3175                      Type pt,
  3176                      Env<AttrContext> env,
  3177                      ResultInfo resultInfo) {
  3178             if (pt.isErroneous()) {
  3179                 return types.createErrorType(site);
  3181             Type owntype; // The computed type of this identifier occurrence.
  3182             switch (sym.kind) {
  3183             case TYP:
  3184                 // For types, the computed type equals the symbol's type,
  3185                 // except for two situations:
  3186                 owntype = sym.type;
  3187                 if (owntype.hasTag(CLASS)) {
  3188                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
  3189                     Type ownOuter = owntype.getEnclosingType();
  3191                     // (a) If the symbol's type is parameterized, erase it
  3192                     // because no type parameters were given.
  3193                     // We recover generic outer type later in visitTypeApply.
  3194                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
  3195                         owntype = types.erasure(owntype);
  3198                     // (b) If the symbol's type is an inner class, then
  3199                     // we have to interpret its outer type as a superclass
  3200                     // of the site type. Example:
  3201                     //
  3202                     // class Tree<A> { class Visitor { ... } }
  3203                     // class PointTree extends Tree<Point> { ... }
  3204                     // ...PointTree.Visitor...
  3205                     //
  3206                     // Then the type of the last expression above is
  3207                     // Tree<Point>.Visitor.
  3208                     else if (ownOuter.hasTag(CLASS) && site != ownOuter) {
  3209                         Type normOuter = site;
  3210                         if (normOuter.hasTag(CLASS))
  3211                             normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
  3212                         if (normOuter == null) // perhaps from an import
  3213                             normOuter = types.erasure(ownOuter);
  3214                         if (normOuter != ownOuter)
  3215                             owntype = new ClassType(
  3216                                 normOuter, List.<Type>nil(), owntype.tsym);
  3219                 break;
  3220             case VAR:
  3221                 VarSymbol v = (VarSymbol)sym;
  3222                 // Test (4): if symbol is an instance field of a raw type,
  3223                 // which is being assigned to, issue an unchecked warning if
  3224                 // its type changes under erasure.
  3225                 if (allowGenerics &&
  3226                     resultInfo.pkind == VAR &&
  3227                     v.owner.kind == TYP &&
  3228                     (v.flags() & STATIC) == 0 &&
  3229                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
  3230                     Type s = types.asOuterSuper(site, v.owner);
  3231                     if (s != null &&
  3232                         s.isRaw() &&
  3233                         !types.isSameType(v.type, v.erasure(types))) {
  3234                         chk.warnUnchecked(tree.pos(),
  3235                                           "unchecked.assign.to.var",
  3236                                           v, s);
  3239                 // The computed type of a variable is the type of the
  3240                 // variable symbol, taken as a member of the site type.
  3241                 owntype = (sym.owner.kind == TYP &&
  3242                            sym.name != names._this && sym.name != names._super)
  3243                     ? types.memberType(site, sym)
  3244                     : sym.type;
  3246                 // If the variable is a constant, record constant value in
  3247                 // computed type.
  3248                 if (v.getConstValue() != null && isStaticReference(tree))
  3249                     owntype = owntype.constType(v.getConstValue());
  3251                 if (resultInfo.pkind == VAL) {
  3252                     owntype = capture(owntype); // capture "names as expressions"
  3254                 break;
  3255             case MTH: {
  3256                 owntype = checkMethod(site, sym,
  3257                         new ResultInfo(VAL, resultInfo.pt.getReturnType(), resultInfo.checkContext),
  3258                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
  3259                         resultInfo.pt.getTypeArguments());
  3260                 break;
  3262             case PCK: case ERR:
  3263                 owntype = sym.type;
  3264                 break;
  3265             default:
  3266                 throw new AssertionError("unexpected kind: " + sym.kind +
  3267                                          " in tree " + tree);
  3270             // Test (1): emit a `deprecation' warning if symbol is deprecated.
  3271             // (for constructors, the error was given when the constructor was
  3272             // resolved)
  3274             if (sym.name != names.init) {
  3275                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
  3276                 chk.checkSunAPI(tree.pos(), sym);
  3279             // Test (3): if symbol is a variable, check that its type and
  3280             // kind are compatible with the prototype and protokind.
  3281             return check(tree, owntype, sym.kind, resultInfo);
  3284         /** Check that variable is initialized and evaluate the variable's
  3285          *  initializer, if not yet done. Also check that variable is not
  3286          *  referenced before it is defined.
  3287          *  @param tree    The tree making up the variable reference.
  3288          *  @param env     The current environment.
  3289          *  @param v       The variable's symbol.
  3290          */
  3291         private void checkInit(JCTree tree,
  3292                                Env<AttrContext> env,
  3293                                VarSymbol v,
  3294                                boolean onlyWarning) {
  3295 //          System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
  3296 //                             tree.pos + " " + v.pos + " " +
  3297 //                             Resolve.isStatic(env));//DEBUG
  3299             // A forward reference is diagnosed if the declaration position
  3300             // of the variable is greater than the current tree position
  3301             // and the tree and variable definition occur in the same class
  3302             // definition.  Note that writes don't count as references.
  3303             // This check applies only to class and instance
  3304             // variables.  Local variables follow different scope rules,
  3305             // and are subject to definite assignment checking.
  3306             if ((env.info.enclVar == v || v.pos > tree.pos) &&
  3307                 v.owner.kind == TYP &&
  3308                 canOwnInitializer(owner(env)) &&
  3309                 v.owner == env.info.scope.owner.enclClass() &&
  3310                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
  3311                 (!env.tree.hasTag(ASSIGN) ||
  3312                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
  3313                 String suffix = (env.info.enclVar == v) ?
  3314                                 "self.ref" : "forward.ref";
  3315                 if (!onlyWarning || isStaticEnumField(v)) {
  3316                     log.error(tree.pos(), "illegal." + suffix);
  3317                 } else if (useBeforeDeclarationWarning) {
  3318                     log.warning(tree.pos(), suffix, v);
  3322             v.getConstValue(); // ensure initializer is evaluated
  3324             checkEnumInitializer(tree, env, v);
  3327         /**
  3328          * Check for illegal references to static members of enum.  In
  3329          * an enum type, constructors and initializers may not
  3330          * reference its static members unless they are constant.
  3332          * @param tree    The tree making up the variable reference.
  3333          * @param env     The current environment.
  3334          * @param v       The variable's symbol.
  3335          * @jls  section 8.9 Enums
  3336          */
  3337         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
  3338             // JLS:
  3339             //
  3340             // "It is a compile-time error to reference a static field
  3341             // of an enum type that is not a compile-time constant
  3342             // (15.28) from constructors, instance initializer blocks,
  3343             // or instance variable initializer expressions of that
  3344             // type. It is a compile-time error for the constructors,
  3345             // instance initializer blocks, or instance variable
  3346             // initializer expressions of an enum constant e to refer
  3347             // to itself or to an enum constant of the same type that
  3348             // is declared to the right of e."
  3349             if (isStaticEnumField(v)) {
  3350                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
  3352                 if (enclClass == null || enclClass.owner == null)
  3353                     return;
  3355                 // See if the enclosing class is the enum (or a
  3356                 // subclass thereof) declaring v.  If not, this
  3357                 // reference is OK.
  3358                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
  3359                     return;
  3361                 // If the reference isn't from an initializer, then
  3362                 // the reference is OK.
  3363                 if (!Resolve.isInitializer(env))
  3364                     return;
  3366                 log.error(tree.pos(), "illegal.enum.static.ref");
  3370         /** Is the given symbol a static, non-constant field of an Enum?
  3371          *  Note: enum literals should not be regarded as such
  3372          */
  3373         private boolean isStaticEnumField(VarSymbol v) {
  3374             return Flags.isEnum(v.owner) &&
  3375                    Flags.isStatic(v) &&
  3376                    !Flags.isConstant(v) &&
  3377                    v.name != names._class;
  3380         /** Can the given symbol be the owner of code which forms part
  3381          *  if class initialization? This is the case if the symbol is
  3382          *  a type or field, or if the symbol is the synthetic method.
  3383          *  owning a block.
  3384          */
  3385         private boolean canOwnInitializer(Symbol sym) {
  3386             return
  3387                 (sym.kind & (VAR | TYP)) != 0 ||
  3388                 (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
  3391     Warner noteWarner = new Warner();
  3393     /**
  3394      * Check that method arguments conform to its instantiation.
  3395      **/
  3396     public Type checkMethod(Type site,
  3397                             Symbol sym,
  3398                             ResultInfo resultInfo,
  3399                             Env<AttrContext> env,
  3400                             final List<JCExpression> argtrees,
  3401                             List<Type> argtypes,
  3402                             List<Type> typeargtypes) {
  3403         // Test (5): if symbol is an instance method of a raw type, issue
  3404         // an unchecked warning if its argument types change under erasure.
  3405         if (allowGenerics &&
  3406             (sym.flags() & STATIC) == 0 &&
  3407             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
  3408             Type s = types.asOuterSuper(site, sym.owner);
  3409             if (s != null && s.isRaw() &&
  3410                 !types.isSameTypes(sym.type.getParameterTypes(),
  3411                                    sym.erasure(types).getParameterTypes())) {
  3412                 chk.warnUnchecked(env.tree.pos(),
  3413                                   "unchecked.call.mbr.of.raw.type",
  3414                                   sym, s);
  3418         if (env.info.defaultSuperCallSite != null) {
  3419             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
  3420                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
  3421                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
  3422                 List<MethodSymbol> icand_sup =
  3423                         types.interfaceCandidates(sup, (MethodSymbol)sym);
  3424                 if (icand_sup.nonEmpty() &&
  3425                         icand_sup.head != sym &&
  3426                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
  3427                     log.error(env.tree.pos(), "illegal.default.super.call", env.info.defaultSuperCallSite,
  3428                         diags.fragment("overridden.default", sym, sup));
  3429                     break;
  3432             env.info.defaultSuperCallSite = null;
  3435         // Compute the identifier's instantiated type.
  3436         // For methods, we need to compute the instance type by
  3437         // Resolve.instantiate from the symbol's type as well as
  3438         // any type arguments and value arguments.
  3439         noteWarner.clear();
  3440         try {
  3441             Type owntype = rs.checkMethod(
  3442                     env,
  3443                     site,
  3444                     sym,
  3445                     resultInfo,
  3446                     argtypes,
  3447                     typeargtypes,
  3448                     noteWarner);
  3450             return chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
  3451                     noteWarner.hasNonSilentLint(LintCategory.UNCHECKED));
  3452         } catch (Infer.InferenceException ex) {
  3453             //invalid target type - propagate exception outwards or report error
  3454             //depending on the current check context
  3455             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
  3456             return types.createErrorType(site);
  3457         } catch (Resolve.InapplicableMethodException ex) {
  3458             Assert.error(ex.getDiagnostic().getMessage(Locale.getDefault()));
  3459             return null;
  3463     public void visitLiteral(JCLiteral tree) {
  3464         result = check(
  3465             tree, litType(tree.typetag).constType(tree.value), VAL, resultInfo);
  3467     //where
  3468     /** Return the type of a literal with given type tag.
  3469      */
  3470     Type litType(TypeTag tag) {
  3471         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
  3474     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
  3475         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], TYP, resultInfo);
  3478     public void visitTypeArray(JCArrayTypeTree tree) {
  3479         Type etype = attribType(tree.elemtype, env);
  3480         Type type = new ArrayType(etype, syms.arrayClass);
  3481         result = check(tree, type, TYP, resultInfo);
  3484     /** Visitor method for parameterized types.
  3485      *  Bound checking is left until later, since types are attributed
  3486      *  before supertype structure is completely known
  3487      */
  3488     public void visitTypeApply(JCTypeApply tree) {
  3489         Type owntype = types.createErrorType(tree.type);
  3491         // Attribute functor part of application and make sure it's a class.
  3492         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
  3494         // Attribute type parameters
  3495         List<Type> actuals = attribTypes(tree.arguments, env);
  3497         if (clazztype.hasTag(CLASS)) {
  3498             List<Type> formals = clazztype.tsym.type.getTypeArguments();
  3499             if (actuals.isEmpty()) //diamond
  3500                 actuals = formals;
  3502             if (actuals.length() == formals.length()) {
  3503                 List<Type> a = actuals;
  3504                 List<Type> f = formals;
  3505                 while (a.nonEmpty()) {
  3506                     a.head = a.head.withTypeVar(f.head);
  3507                     a = a.tail;
  3508                     f = f.tail;
  3510                 // Compute the proper generic outer
  3511                 Type clazzOuter = clazztype.getEnclosingType();
  3512                 if (clazzOuter.hasTag(CLASS)) {
  3513                     Type site;
  3514                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
  3515                     if (clazz.hasTag(IDENT)) {
  3516                         site = env.enclClass.sym.type;
  3517                     } else if (clazz.hasTag(SELECT)) {
  3518                         site = ((JCFieldAccess) clazz).selected.type;
  3519                     } else throw new AssertionError(""+tree);
  3520                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
  3521                         if (site.hasTag(CLASS))
  3522                             site = types.asOuterSuper(site, clazzOuter.tsym);
  3523                         if (site == null)
  3524                             site = types.erasure(clazzOuter);
  3525                         clazzOuter = site;
  3528                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
  3529             } else {
  3530                 if (formals.length() != 0) {
  3531                     log.error(tree.pos(), "wrong.number.type.args",
  3532                               Integer.toString(formals.length()));
  3533                 } else {
  3534                     log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym);
  3536                 owntype = types.createErrorType(tree.type);
  3539         result = check(tree, owntype, TYP, resultInfo);
  3542     public void visitTypeUnion(JCTypeUnion tree) {
  3543         ListBuffer<Type> multicatchTypes = ListBuffer.lb();
  3544         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
  3545         for (JCExpression typeTree : tree.alternatives) {
  3546             Type ctype = attribType(typeTree, env);
  3547             ctype = chk.checkType(typeTree.pos(),
  3548                           chk.checkClassType(typeTree.pos(), ctype),
  3549                           syms.throwableType);
  3550             if (!ctype.isErroneous()) {
  3551                 //check that alternatives of a union type are pairwise
  3552                 //unrelated w.r.t. subtyping
  3553                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
  3554                     for (Type t : multicatchTypes) {
  3555                         boolean sub = types.isSubtype(ctype, t);
  3556                         boolean sup = types.isSubtype(t, ctype);
  3557                         if (sub || sup) {
  3558                             //assume 'a' <: 'b'
  3559                             Type a = sub ? ctype : t;
  3560                             Type b = sub ? t : ctype;
  3561                             log.error(typeTree.pos(), "multicatch.types.must.be.disjoint", a, b);
  3565                 multicatchTypes.append(ctype);
  3566                 if (all_multicatchTypes != null)
  3567                     all_multicatchTypes.append(ctype);
  3568             } else {
  3569                 if (all_multicatchTypes == null) {
  3570                     all_multicatchTypes = ListBuffer.lb();
  3571                     all_multicatchTypes.appendList(multicatchTypes);
  3573                 all_multicatchTypes.append(ctype);
  3576         Type t = check(tree, types.lub(multicatchTypes.toList()), TYP, resultInfo);
  3577         if (t.hasTag(CLASS)) {
  3578             List<Type> alternatives =
  3579                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
  3580             t = new UnionClassType((ClassType) t, alternatives);
  3582         tree.type = result = t;
  3585     public void visitTypeIntersection(JCTypeIntersection tree) {
  3586         attribTypes(tree.bounds, env);
  3587         tree.type = result = checkIntersection(tree, tree.bounds);
  3590      public void visitTypeParameter(JCTypeParameter tree) {
  3591         TypeVar typeVar = (TypeVar)tree.type;
  3592         if (!typeVar.bound.isErroneous()) {
  3593             //fixup type-parameter bound computed in 'attribTypeVariables'
  3594             typeVar.bound = checkIntersection(tree, tree.bounds);
  3598     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
  3599         Set<Type> boundSet = new HashSet<Type>();
  3600         if (bounds.nonEmpty()) {
  3601             // accept class or interface or typevar as first bound.
  3602             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
  3603             boundSet.add(types.erasure(bounds.head.type));
  3604             if (bounds.head.type.isErroneous()) {
  3605                 return bounds.head.type;
  3607             else if (bounds.head.type.hasTag(TYPEVAR)) {
  3608                 // if first bound was a typevar, do not accept further bounds.
  3609                 if (bounds.tail.nonEmpty()) {
  3610                     log.error(bounds.tail.head.pos(),
  3611                               "type.var.may.not.be.followed.by.other.bounds");
  3612                     return bounds.head.type;
  3614             } else {
  3615                 // if first bound was a class or interface, accept only interfaces
  3616                 // as further bounds.
  3617                 for (JCExpression bound : bounds.tail) {
  3618                     bound.type = checkBase(bound.type, bound, env, false, true, false);
  3619                     if (bound.type.isErroneous()) {
  3620                         bounds = List.of(bound);
  3622                     else if (bound.type.hasTag(CLASS)) {
  3623                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
  3629         if (bounds.length() == 0) {
  3630             return syms.objectType;
  3631         } else if (bounds.length() == 1) {
  3632             return bounds.head.type;
  3633         } else {
  3634             Type owntype = types.makeCompoundType(TreeInfo.types(bounds));
  3635             if (tree.hasTag(TYPEINTERSECTION)) {
  3636                 ((IntersectionClassType)owntype).intersectionKind =
  3637                         IntersectionClassType.IntersectionKind.EXPLICIT;
  3639             // ... the variable's bound is a class type flagged COMPOUND
  3640             // (see comment for TypeVar.bound).
  3641             // In this case, generate a class tree that represents the
  3642             // bound class, ...
  3643             JCExpression extending;
  3644             List<JCExpression> implementing;
  3645             if (!bounds.head.type.isInterface()) {
  3646                 extending = bounds.head;
  3647                 implementing = bounds.tail;
  3648             } else {
  3649                 extending = null;
  3650                 implementing = bounds;
  3652             JCClassDecl cd = make.at(tree).ClassDef(
  3653                 make.Modifiers(PUBLIC | ABSTRACT),
  3654                 names.empty, List.<JCTypeParameter>nil(),
  3655                 extending, implementing, List.<JCTree>nil());
  3657             ClassSymbol c = (ClassSymbol)owntype.tsym;
  3658             Assert.check((c.flags() & COMPOUND) != 0);
  3659             cd.sym = c;
  3660             c.sourcefile = env.toplevel.sourcefile;
  3662             // ... and attribute the bound class
  3663             c.flags_field |= UNATTRIBUTED;
  3664             Env<AttrContext> cenv = enter.classEnv(cd, env);
  3665             enter.typeEnvs.put(c, cenv);
  3666             attribClass(c);
  3667             return owntype;
  3671     public void visitWildcard(JCWildcard tree) {
  3672         //- System.err.println("visitWildcard("+tree+");");//DEBUG
  3673         Type type = (tree.kind.kind == BoundKind.UNBOUND)
  3674             ? syms.objectType
  3675             : attribType(tree.inner, env);
  3676         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
  3677                                               tree.kind.kind,
  3678                                               syms.boundClass),
  3679                        TYP, resultInfo);
  3682     public void visitAnnotation(JCAnnotation tree) {
  3683         log.error(tree.pos(), "annotation.not.valid.for.type", pt());
  3684         result = tree.type = syms.errType;
  3687     public void visitErroneous(JCErroneous tree) {
  3688         if (tree.errs != null)
  3689             for (JCTree err : tree.errs)
  3690                 attribTree(err, env, new ResultInfo(ERR, pt()));
  3691         result = tree.type = syms.errType;
  3694     /** Default visitor method for all other trees.
  3695      */
  3696     public void visitTree(JCTree tree) {
  3697         throw new AssertionError();
  3700     /**
  3701      * Attribute an env for either a top level tree or class declaration.
  3702      */
  3703     public void attrib(Env<AttrContext> env) {
  3704         if (env.tree.hasTag(TOPLEVEL))
  3705             attribTopLevel(env);
  3706         else
  3707             attribClass(env.tree.pos(), env.enclClass.sym);
  3710     /**
  3711      * Attribute a top level tree. These trees are encountered when the
  3712      * package declaration has annotations.
  3713      */
  3714     public void attribTopLevel(Env<AttrContext> env) {
  3715         JCCompilationUnit toplevel = env.toplevel;
  3716         try {
  3717             annotate.flush();
  3718             chk.validateAnnotations(toplevel.packageAnnotations, toplevel.packge);
  3719         } catch (CompletionFailure ex) {
  3720             chk.completionError(toplevel.pos(), ex);
  3724     /** Main method: attribute class definition associated with given class symbol.
  3725      *  reporting completion failures at the given position.
  3726      *  @param pos The source position at which completion errors are to be
  3727      *             reported.
  3728      *  @param c   The class symbol whose definition will be attributed.
  3729      */
  3730     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
  3731         try {
  3732             annotate.flush();
  3733             attribClass(c);
  3734         } catch (CompletionFailure ex) {
  3735             chk.completionError(pos, ex);
  3739     /** Attribute class definition associated with given class symbol.
  3740      *  @param c   The class symbol whose definition will be attributed.
  3741      */
  3742     void attribClass(ClassSymbol c) throws CompletionFailure {
  3743         if (c.type.hasTag(ERROR)) return;
  3745         // Check for cycles in the inheritance graph, which can arise from
  3746         // ill-formed class files.
  3747         chk.checkNonCyclic(null, c.type);
  3749         Type st = types.supertype(c.type);
  3750         if ((c.flags_field & Flags.COMPOUND) == 0) {
  3751             // First, attribute superclass.
  3752             if (st.hasTag(CLASS))
  3753                 attribClass((ClassSymbol)st.tsym);
  3755             // Next attribute owner, if it is a class.
  3756             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
  3757                 attribClass((ClassSymbol)c.owner);
  3760         // The previous operations might have attributed the current class
  3761         // if there was a cycle. So we test first whether the class is still
  3762         // UNATTRIBUTED.
  3763         if ((c.flags_field & UNATTRIBUTED) != 0) {
  3764             c.flags_field &= ~UNATTRIBUTED;
  3766             // Get environment current at the point of class definition.
  3767             Env<AttrContext> env = enter.typeEnvs.get(c);
  3769             // The info.lint field in the envs stored in enter.typeEnvs is deliberately uninitialized,
  3770             // because the annotations were not available at the time the env was created. Therefore,
  3771             // we look up the environment chain for the first enclosing environment for which the
  3772             // lint value is set. Typically, this is the parent env, but might be further if there
  3773             // are any envs created as a result of TypeParameter nodes.
  3774             Env<AttrContext> lintEnv = env;
  3775             while (lintEnv.info.lint == null)
  3776                 lintEnv = lintEnv.next;
  3778             // Having found the enclosing lint value, we can initialize the lint value for this class
  3779             env.info.lint = lintEnv.info.lint.augment(c.annotations, c.flags());
  3781             Lint prevLint = chk.setLint(env.info.lint);
  3782             JavaFileObject prev = log.useSource(c.sourcefile);
  3783             ResultInfo prevReturnRes = env.info.returnResult;
  3785             try {
  3786                 env.info.returnResult = null;
  3787                 // java.lang.Enum may not be subclassed by a non-enum
  3788                 if (st.tsym == syms.enumSym &&
  3789                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
  3790                     log.error(env.tree.pos(), "enum.no.subclassing");
  3792                 // Enums may not be extended by source-level classes
  3793                 if (st.tsym != null &&
  3794                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
  3795                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0) &&
  3796                     !target.compilerBootstrap(c)) {
  3797                     log.error(env.tree.pos(), "enum.types.not.extensible");
  3799                 attribClassBody(env, c);
  3801                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
  3802             } finally {
  3803                 env.info.returnResult = prevReturnRes;
  3804                 log.useSource(prev);
  3805                 chk.setLint(prevLint);
  3811     public void visitImport(JCImport tree) {
  3812         // nothing to do
  3815     /** Finish the attribution of a class. */
  3816     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
  3817         JCClassDecl tree = (JCClassDecl)env.tree;
  3818         Assert.check(c == tree.sym);
  3820         // Validate annotations
  3821         chk.validateAnnotations(tree.mods.annotations, c);
  3823         // Validate type parameters, supertype and interfaces.
  3824         attribStats(tree.typarams, env);
  3825         if (!c.isAnonymous()) {
  3826             //already checked if anonymous
  3827             chk.validate(tree.typarams, env);
  3828             chk.validate(tree.extending, env);
  3829             chk.validate(tree.implementing, env);
  3832         // If this is a non-abstract class, check that it has no abstract
  3833         // methods or unimplemented methods of an implemented interface.
  3834         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
  3835             if (!relax)
  3836                 chk.checkAllDefined(tree.pos(), c);
  3839         if ((c.flags() & ANNOTATION) != 0) {
  3840             if (tree.implementing.nonEmpty())
  3841                 log.error(tree.implementing.head.pos(),
  3842                           "cant.extend.intf.annotation");
  3843             if (tree.typarams.nonEmpty())
  3844                 log.error(tree.typarams.head.pos(),
  3845                           "intf.annotation.cant.have.type.params");
  3847             // If this annotation has a @Repeatable, validate
  3848             Attribute.Compound repeatable = c.attribute(syms.repeatableType.tsym);
  3849             if (repeatable != null) {
  3850                 // get diagnostic position for error reporting
  3851                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
  3852                 Assert.checkNonNull(cbPos);
  3854                 chk.validateRepeatable(c, repeatable, cbPos);
  3856         } else {
  3857             // Check that all extended classes and interfaces
  3858             // are compatible (i.e. no two define methods with same arguments
  3859             // yet different return types).  (JLS 8.4.6.3)
  3860             chk.checkCompatibleSupertypes(tree.pos(), c.type);
  3861             if (allowDefaultMethods) {
  3862                 chk.checkDefaultMethodClashes(tree.pos(), c.type);
  3866         // Check that class does not import the same parameterized interface
  3867         // with two different argument lists.
  3868         chk.checkClassBounds(tree.pos(), c.type);
  3870         tree.type = c.type;
  3872         for (List<JCTypeParameter> l = tree.typarams;
  3873              l.nonEmpty(); l = l.tail) {
  3874              Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope);
  3877         // Check that a generic class doesn't extend Throwable
  3878         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
  3879             log.error(tree.extending.pos(), "generic.throwable");
  3881         // Check that all methods which implement some
  3882         // method conform to the method they implement.
  3883         chk.checkImplementations(tree);
  3885         //check that a resource implementing AutoCloseable cannot throw InterruptedException
  3886         checkAutoCloseable(tree.pos(), env, c.type);
  3888         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
  3889             // Attribute declaration
  3890             attribStat(l.head, env);
  3891             // Check that declarations in inner classes are not static (JLS 8.1.2)
  3892             // Make an exception for static constants.
  3893             if (c.owner.kind != PCK &&
  3894                 ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
  3895                 (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
  3896                 Symbol sym = null;
  3897                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
  3898                 if (sym == null ||
  3899                     sym.kind != VAR ||
  3900                     ((VarSymbol) sym).getConstValue() == null)
  3901                     log.error(l.head.pos(), "icls.cant.have.static.decl", c);
  3905         // Check for cycles among non-initial constructors.
  3906         chk.checkCyclicConstructors(tree);
  3908         // Check for cycles among annotation elements.
  3909         chk.checkNonCyclicElements(tree);
  3911         // Check for proper use of serialVersionUID
  3912         if (env.info.lint.isEnabled(LintCategory.SERIAL) &&
  3913             isSerializable(c) &&
  3914             (c.flags() & Flags.ENUM) == 0 &&
  3915             (c.flags() & ABSTRACT) == 0) {
  3916             checkSerialVersionUID(tree, c);
  3919         // where
  3920         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
  3921         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
  3922             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
  3923                 if (types.isSameType(al.head.annotationType.type, t))
  3924                     return al.head.pos();
  3927             return null;
  3930         /** check if a class is a subtype of Serializable, if that is available. */
  3931         private boolean isSerializable(ClassSymbol c) {
  3932             try {
  3933                 syms.serializableType.complete();
  3935             catch (CompletionFailure e) {
  3936                 return false;
  3938             return types.isSubtype(c.type, syms.serializableType);
  3941         /** Check that an appropriate serialVersionUID member is defined. */
  3942         private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
  3944             // check for presence of serialVersionUID
  3945             Scope.Entry e = c.members().lookup(names.serialVersionUID);
  3946             while (e.scope != null && e.sym.kind != VAR) e = e.next();
  3947             if (e.scope == null) {
  3948                 log.warning(LintCategory.SERIAL,
  3949                         tree.pos(), "missing.SVUID", c);
  3950                 return;
  3953             // check that it is static final
  3954             VarSymbol svuid = (VarSymbol)e.sym;
  3955             if ((svuid.flags() & (STATIC | FINAL)) !=
  3956                 (STATIC | FINAL))
  3957                 log.warning(LintCategory.SERIAL,
  3958                         TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
  3960             // check that it is long
  3961             else if (!svuid.type.hasTag(LONG))
  3962                 log.warning(LintCategory.SERIAL,
  3963                         TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c);
  3965             // check constant
  3966             else if (svuid.getConstValue() == null)
  3967                 log.warning(LintCategory.SERIAL,
  3968                         TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c);
  3971     private Type capture(Type type) {
  3972         return types.capture(type);
  3975     // <editor-fold desc="post-attribution visitor">
  3977     /**
  3978      * Handle missing types/symbols in an AST. This routine is useful when
  3979      * the compiler has encountered some errors (which might have ended up
  3980      * terminating attribution abruptly); if the compiler is used in fail-over
  3981      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
  3982      * prevents NPE to be progagated during subsequent compilation steps.
  3983      */
  3984     public void postAttr(JCTree tree) {
  3985         new PostAttrAnalyzer().scan(tree);
  3988     class PostAttrAnalyzer extends TreeScanner {
  3990         private void initTypeIfNeeded(JCTree that) {
  3991             if (that.type == null) {
  3992                 that.type = syms.unknownType;
  3996         @Override
  3997         public void scan(JCTree tree) {
  3998             if (tree == null) return;
  3999             if (tree instanceof JCExpression) {
  4000                 initTypeIfNeeded(tree);
  4002             super.scan(tree);
  4005         @Override
  4006         public void visitIdent(JCIdent that) {
  4007             if (that.sym == null) {
  4008                 that.sym = syms.unknownSymbol;
  4012         @Override
  4013         public void visitSelect(JCFieldAccess that) {
  4014             if (that.sym == null) {
  4015                 that.sym = syms.unknownSymbol;
  4017             super.visitSelect(that);
  4020         @Override
  4021         public void visitClassDef(JCClassDecl that) {
  4022             initTypeIfNeeded(that);
  4023             if (that.sym == null) {
  4024                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
  4026             super.visitClassDef(that);
  4029         @Override
  4030         public void visitMethodDef(JCMethodDecl that) {
  4031             initTypeIfNeeded(that);
  4032             if (that.sym == null) {
  4033                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
  4035             super.visitMethodDef(that);
  4038         @Override
  4039         public void visitVarDef(JCVariableDecl that) {
  4040             initTypeIfNeeded(that);
  4041             if (that.sym == null) {
  4042                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
  4043                 that.sym.adr = 0;
  4045             super.visitVarDef(that);
  4048         @Override
  4049         public void visitNewClass(JCNewClass that) {
  4050             if (that.constructor == null) {
  4051                 that.constructor = new MethodSymbol(0, names.init, syms.unknownType, syms.noSymbol);
  4053             if (that.constructorType == null) {
  4054                 that.constructorType = syms.unknownType;
  4056             super.visitNewClass(that);
  4059         @Override
  4060         public void visitAssignop(JCAssignOp that) {
  4061             if (that.operator == null)
  4062                 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
  4063             super.visitAssignop(that);
  4066         @Override
  4067         public void visitBinary(JCBinary that) {
  4068             if (that.operator == null)
  4069                 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
  4070             super.visitBinary(that);
  4073         @Override
  4074         public void visitUnary(JCUnary that) {
  4075             if (that.operator == null)
  4076                 that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
  4077             super.visitUnary(that);
  4080         @Override
  4081         public void visitReference(JCMemberReference that) {
  4082             super.visitReference(that);
  4083             if (that.sym == null) {
  4084                 that.sym = new MethodSymbol(0, names.empty, syms.unknownType, syms.noSymbol);
  4088     // </editor-fold>

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