1 /*
   2  * Copyright (c) 1999, 2023, 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  */
  25 
  26 package com.sun.tools.javac.comp;
  27 
  28 import java.util.*;
  29 import java.util.function.BiConsumer;
  30 import java.util.function.Consumer;
  31 import java.util.stream.Stream;
  32 
  33 import javax.lang.model.element.ElementKind;
  34 import javax.tools.JavaFileObject;
  35 
  36 import com.sun.source.tree.CaseTree;
  37 import com.sun.source.tree.IdentifierTree;
  38 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
  39 import com.sun.source.tree.MemberSelectTree;
  40 import com.sun.source.tree.TreeVisitor;
  41 import com.sun.source.util.SimpleTreeVisitor;
  42 import com.sun.tools.javac.code.*;
  43 import com.sun.tools.javac.code.Lint.LintCategory;
  44 import com.sun.tools.javac.code.Scope.WriteableScope;
  45 import com.sun.tools.javac.code.Source.Feature;
  46 import com.sun.tools.javac.code.Symbol.*;
  47 import com.sun.tools.javac.code.Type.*;
  48 import com.sun.tools.javac.code.Types.FunctionDescriptorLookupError;
  49 import com.sun.tools.javac.comp.ArgumentAttr.LocalCacheContext;
  50 import com.sun.tools.javac.comp.Check.CheckContext;
  51 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
  52 import com.sun.tools.javac.comp.MatchBindingsComputer.MatchBindings;
  53 import com.sun.tools.javac.jvm.*;
  54 
  55 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
  56 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
  57 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
  58 
  59 import com.sun.tools.javac.resources.CompilerProperties.Errors;
  60 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  61 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
  62 import com.sun.tools.javac.tree.*;
  63 import com.sun.tools.javac.tree.JCTree.*;
  64 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
  65 import com.sun.tools.javac.util.*;
  66 import com.sun.tools.javac.util.DefinedBy.Api;
  67 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  68 import com.sun.tools.javac.util.JCDiagnostic.Error;
  69 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
  70 import com.sun.tools.javac.util.JCDiagnostic.Warning;
  71 import com.sun.tools.javac.util.List;
  72 
  73 import static com.sun.tools.javac.code.Flags.*;
  74 import static com.sun.tools.javac.code.Flags.ANNOTATION;
  75 import static com.sun.tools.javac.code.Flags.BLOCK;
  76 import static com.sun.tools.javac.code.Kinds.*;
  77 import static com.sun.tools.javac.code.Kinds.Kind.*;
  78 import static com.sun.tools.javac.code.TypeTag.*;
  79 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
  80 import static com.sun.tools.javac.tree.JCTree.Tag.*;
  81 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
  82 
  83 /** This is the main context-dependent analysis phase in GJC. It
  84  *  encompasses name resolution, type checking and constant folding as
  85  *  subtasks. Some subtasks involve auxiliary classes.
  86  *  @see Check
  87  *  @see Resolve
  88  *  @see ConstFold
  89  *  @see Infer
  90  *
  91  *  <p><b>This is NOT part of any supported API.
  92  *  If you write code that depends on this, you do so at your own risk.
  93  *  This code and its internal interfaces are subject to change or
  94  *  deletion without notice.</b>
  95  */
  96 public class Attr extends JCTree.Visitor {
  97     protected static final Context.Key<Attr> attrKey = new Context.Key<>();
  98 
  99     final Names names;
 100     final Log log;
 101     final Symtab syms;
 102     final Resolve rs;
 103     final Operators operators;
 104     final Infer infer;
 105     final Analyzer analyzer;
 106     final DeferredAttr deferredAttr;
 107     final Check chk;
 108     final Flow flow;
 109     final MemberEnter memberEnter;
 110     final TypeEnter typeEnter;
 111     final TreeMaker make;
 112     final ConstFold cfolder;
 113     final Enter enter;
 114     final Target target;
 115     final Types types;
 116     final Preview preview;
 117     final JCDiagnostic.Factory diags;
 118     final TypeAnnotations typeAnnotations;
 119     final DeferredLintHandler deferredLintHandler;
 120     final TypeEnvs typeEnvs;
 121     final Dependencies dependencies;
 122     final Annotate annotate;
 123     final ArgumentAttr argumentAttr;
 124     final MatchBindingsComputer matchBindingsComputer;
 125     final AttrRecover attrRecover;
 126 
 127     public static Attr instance(Context context) {
 128         Attr instance = context.get(attrKey);
 129         if (instance == null)
 130             instance = new Attr(context);
 131         return instance;
 132     }
 133 
 134     @SuppressWarnings("this-escape")
 135     protected Attr(Context context) {
 136         context.put(attrKey, this);
 137 
 138         names = Names.instance(context);
 139         log = Log.instance(context);
 140         syms = Symtab.instance(context);
 141         rs = Resolve.instance(context);
 142         operators = Operators.instance(context);
 143         chk = Check.instance(context);
 144         flow = Flow.instance(context);
 145         memberEnter = MemberEnter.instance(context);
 146         typeEnter = TypeEnter.instance(context);
 147         make = TreeMaker.instance(context);
 148         enter = Enter.instance(context);
 149         infer = Infer.instance(context);
 150         analyzer = Analyzer.instance(context);
 151         deferredAttr = DeferredAttr.instance(context);
 152         cfolder = ConstFold.instance(context);
 153         target = Target.instance(context);
 154         types = Types.instance(context);
 155         preview = Preview.instance(context);
 156         diags = JCDiagnostic.Factory.instance(context);
 157         annotate = Annotate.instance(context);
 158         typeAnnotations = TypeAnnotations.instance(context);
 159         deferredLintHandler = DeferredLintHandler.instance(context);
 160         typeEnvs = TypeEnvs.instance(context);
 161         dependencies = Dependencies.instance(context);
 162         argumentAttr = ArgumentAttr.instance(context);
 163         matchBindingsComputer = MatchBindingsComputer.instance(context);
 164         attrRecover = AttrRecover.instance(context);
 165 
 166         Options options = Options.instance(context);
 167 
 168         Source source = Source.instance(context);
 169         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 170         allowRecords = Feature.RECORDS.allowedInSource(source);
 171         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 172                              Feature.PATTERN_SWITCH.allowedInSource(source);
 173         allowUnconditionalPatternsInstanceOf =
 174                              Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 175         sourceName = source.name;
 176         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 177 
 178         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 179         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 180         unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
 181         methodAttrInfo = new MethodAttrInfo();
 182         unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
 183         unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
 184         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
 185     }
 186 
 187     /** Switch: reifiable types in instanceof enabled?
 188      */
 189     boolean allowReifiableTypesInInstanceof;
 190 
 191     /** Are records allowed
 192      */
 193     private final boolean allowRecords;
 194 
 195     /** Are patterns in switch allowed
 196      */
 197     private final boolean allowPatternSwitch;
 198 
 199     /** Are unconditional patterns in instanceof allowed
 200      */
 201     private final boolean allowUnconditionalPatternsInstanceOf;
 202 
 203     /**
 204      * Switch: warn about use of variable before declaration?
 205      * RFE: 6425594
 206      */
 207     boolean useBeforeDeclarationWarning;
 208 
 209     /**
 210      * Switch: name of source level; used for error reporting.
 211      */
 212     String sourceName;
 213 
 214     /** Check kind and type of given tree against protokind and prototype.
 215      *  If check succeeds, store type in tree and return it.
 216      *  If check fails, store errType in tree and return it.
 217      *  No checks are performed if the prototype is a method type.
 218      *  It is not necessary in this case since we know that kind and type
 219      *  are correct.
 220      *
 221      *  @param tree     The tree whose kind and type is checked
 222      *  @param found    The computed type of the tree
 223      *  @param ownkind  The computed kind of the tree
 224      *  @param resultInfo  The expected result of the tree
 225      */
 226     Type check(final JCTree tree,
 227                final Type found,
 228                final KindSelector ownkind,
 229                final ResultInfo resultInfo) {
 230         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 231         Type owntype;
 232         boolean shouldCheck = !found.hasTag(ERROR) &&
 233                 !resultInfo.pt.hasTag(METHOD) &&
 234                 !resultInfo.pt.hasTag(FORALL);
 235         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 236             log.error(tree.pos(),
 237                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 238                                             ownkind.kindNames()));
 239             owntype = types.createErrorType(found);
 240         } else if (inferenceContext.free(found)) {
 241             //delay the check if there are inference variables in the found type
 242             //this means we are dealing with a partially inferred poly expression
 243             owntype = shouldCheck ? resultInfo.pt : found;
 244             if (resultInfo.checkMode.installPostInferenceHook()) {
 245                 inferenceContext.addFreeTypeListener(List.of(found),
 246                         instantiatedContext -> {
 247                             ResultInfo pendingResult =
 248                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 249                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 250                         });
 251             }
 252         } else {
 253             owntype = shouldCheck ?
 254             resultInfo.check(tree, found) :
 255             found;
 256         }
 257         if (resultInfo.checkMode.updateTreeType()) {
 258             tree.type = owntype;
 259         }
 260         return owntype;
 261     }
 262 
 263     /** Is given blank final variable assignable, i.e. in a scope where it
 264      *  may be assigned to even though it is final?
 265      *  @param v      The blank final variable.
 266      *  @param env    The current environment.
 267      */
 268     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 269         Symbol owner = env.info.scope.owner;
 270            // owner refers to the innermost variable, method or
 271            // initializer block declaration at this point.
 272         boolean isAssignable =
 273             v.owner == owner
 274             ||
 275             ((owner.name == names.init ||    // i.e. we are in a constructor
 276               owner.kind == VAR ||           // i.e. we are in a variable initializer
 277               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 278              &&
 279              v.owner == owner.owner
 280              &&
 281              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 282         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 283         return isAssignable & !insideCompactConstructor;
 284     }
 285 
 286     /** Check that variable can be assigned to.
 287      *  @param pos    The current source code position.
 288      *  @param v      The assigned variable
 289      *  @param base   If the variable is referred to in a Select, the part
 290      *                to the left of the `.', null otherwise.
 291      *  @param env    The current environment.
 292      */
 293     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 294         if (v.name == names._this) {
 295             log.error(pos, Errors.CantAssignValToThis);
 296         } else if ((v.flags() & FINAL) != 0 &&
 297             ((v.flags() & HASINIT) != 0
 298              ||
 299              !((base == null ||
 300                TreeInfo.isThisQualifier(base)) &&
 301                isAssignableAsBlankFinal(v, env)))) {
 302             if (v.isResourceVariable()) { //TWR resource
 303                 log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
 304             } else {
 305                 log.error(pos, Errors.CantAssignValToVar(Flags.toSource(v.flags() & (STATIC | FINAL)), v));
 306             }
 307         }
 308 
 309         if (!env.info.ctorPrologue &&
 310                 v.owner.isValueClass() &&
 311                 !env.info.instanceInitializerBlock && // it is OK instance initializer blocks will go after super() anyways
 312                 v.owner.kind == TYP &&
 313                 v.owner == env.enclClass.sym &&
 314                 (v.flags() & STATIC) == 0 &&
 315                 (base == null ||
 316                         TreeInfo.isExplicitThisReference(types, (ClassType)env.enclClass.type, base))) {
 317             log.error(pos, Errors.CantRefAfterCtorCalled(v));
 318         }
 319     }
 320 
 321     /** Does tree represent a static reference to an identifier?
 322      *  It is assumed that tree is either a SELECT or an IDENT.
 323      *  We have to weed out selects from non-type names here.
 324      *  @param tree    The candidate tree.
 325      */
 326     boolean isStaticReference(JCTree tree) {
 327         if (tree.hasTag(SELECT)) {
 328             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 329             if (lsym == null || lsym.kind != TYP) {
 330                 return false;
 331             }
 332         }
 333         return true;
 334     }
 335 
 336     /** Is this symbol a type?
 337      */
 338     static boolean isType(Symbol sym) {
 339         return sym != null && sym.kind == TYP;
 340     }
 341 
 342     /** The current `this' symbol.
 343      *  @param env    The current environment.
 344      */
 345     Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
 346         return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
 347     }
 348 
 349     /** Attribute a parsed identifier.
 350      * @param tree Parsed identifier name
 351      * @param topLevel The toplevel to use
 352      */
 353     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 354         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 355         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 356                                            syms.errSymbol.name,
 357                                            null, null, null, null);
 358         localEnv.enclClass.sym = syms.errSymbol;
 359         return attribIdent(tree, localEnv);
 360     }
 361 
 362     /** Attribute a parsed identifier.
 363      * @param tree Parsed identifier name
 364      * @param env The env to use
 365      */
 366     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 367         return tree.accept(identAttributer, env);
 368     }
 369     // where
 370         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 371         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 372             @Override @DefinedBy(Api.COMPILER_TREE)
 373             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 374                 Symbol site = visit(node.getExpression(), env);
 375                 if (site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 376                     return site;
 377                 Name name = (Name)node.getIdentifier();
 378                 if (site.kind == PCK) {
 379                     env.toplevel.packge = (PackageSymbol)site;
 380                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 381                             KindSelector.TYP_PCK);
 382                 } else {
 383                     env.enclClass.sym = (ClassSymbol)site;
 384                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 385                 }
 386             }
 387 
 388             @Override @DefinedBy(Api.COMPILER_TREE)
 389             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 390                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 391             }
 392         }
 393 
 394     public Type coerce(Type etype, Type ttype) {
 395         return cfolder.coerce(etype, ttype);
 396     }
 397 
 398     public Type attribType(JCTree node, TypeSymbol sym) {
 399         Env<AttrContext> env = typeEnvs.get(sym);
 400         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 401         return attribTree(node, localEnv, unknownTypeInfo);
 402     }
 403 
 404     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 405         // Attribute qualifying package or class.
 406         JCFieldAccess s = tree.qualid;
 407         return attribTree(s.selected, env,
 408                           new ResultInfo(tree.staticImport ?
 409                                          KindSelector.TYP : KindSelector.TYP_PCK,
 410                        Type.noType));
 411     }
 412 
 413     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 414         return attribToTree(expr, env, tree, unknownExprInfo);
 415     }
 416 
 417     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 418         return attribToTree(stmt, env, tree, statInfo);
 419     }
 420 
 421     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 422         breakTree = tree;
 423         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 424         try {
 425             deferredAttr.attribSpeculative(root, env, resultInfo,
 426                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 427                     argumentAttr.withLocalCacheContext());
 428             attrRecover.doRecovery();
 429         } catch (BreakAttr b) {
 430             return b.env;
 431         } catch (AssertionError ae) {
 432             if (ae.getCause() instanceof BreakAttr breakAttr) {
 433                 return breakAttr.env;
 434             } else {
 435                 throw ae;
 436             }
 437         } finally {
 438             breakTree = null;
 439             log.useSource(prev);
 440         }
 441         return env;
 442     }
 443 
 444     private JCTree breakTree = null;
 445 
 446     private static class BreakAttr extends RuntimeException {
 447         static final long serialVersionUID = -6924771130405446405L;
 448         private transient Env<AttrContext> env;
 449         private BreakAttr(Env<AttrContext> env) {
 450             this.env = env;
 451         }
 452     }
 453 
 454     /**
 455      * Mode controlling behavior of Attr.Check
 456      */
 457     enum CheckMode {
 458 
 459         NORMAL,
 460 
 461         /**
 462          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 463          * that the captured var cache in {@code InferenceContext} will be used in read-only
 464          * mode when performing inference checks.
 465          */
 466         NO_TREE_UPDATE {
 467             @Override
 468             public boolean updateTreeType() {
 469                 return false;
 470             }
 471         },
 472         /**
 473          * Mode signalling that caller will manage free types in tree decorations.
 474          */
 475         NO_INFERENCE_HOOK {
 476             @Override
 477             public boolean installPostInferenceHook() {
 478                 return false;
 479             }
 480         };
 481 
 482         public boolean updateTreeType() {
 483             return true;
 484         }
 485         public boolean installPostInferenceHook() {
 486             return true;
 487         }
 488     }
 489 
 490 
 491     class ResultInfo {
 492         final KindSelector pkind;
 493         final Type pt;
 494         final CheckContext checkContext;
 495         final CheckMode checkMode;
 496 
 497         ResultInfo(KindSelector pkind, Type pt) {
 498             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 499         }
 500 
 501         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 502             this(pkind, pt, chk.basicHandler, checkMode);
 503         }
 504 
 505         protected ResultInfo(KindSelector pkind,
 506                              Type pt, CheckContext checkContext) {
 507             this(pkind, pt, checkContext, CheckMode.NORMAL);
 508         }
 509 
 510         protected ResultInfo(KindSelector pkind,
 511                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 512             this.pkind = pkind;
 513             this.pt = pt;
 514             this.checkContext = checkContext;
 515             this.checkMode = checkMode;
 516         }
 517 
 518         /**
 519          * Should {@link Attr#attribTree} use the {@code ArgumentAttr} visitor instead of this one?
 520          * @param tree The tree to be type-checked.
 521          * @return true if {@code ArgumentAttr} should be used.
 522          */
 523         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 524 
 525         protected Type check(final DiagnosticPosition pos, final Type found) {
 526             return chk.checkType(pos, found, pt, checkContext);
 527         }
 528 
 529         protected ResultInfo dup(Type newPt) {
 530             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 531         }
 532 
 533         protected ResultInfo dup(CheckContext newContext) {
 534             return new ResultInfo(pkind, pt, newContext, checkMode);
 535         }
 536 
 537         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 538             return new ResultInfo(pkind, newPt, newContext, checkMode);
 539         }
 540 
 541         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 542             return new ResultInfo(pkind, newPt, newContext, newMode);
 543         }
 544 
 545         protected ResultInfo dup(CheckMode newMode) {
 546             return new ResultInfo(pkind, pt, checkContext, newMode);
 547         }
 548 
 549         @Override
 550         public String toString() {
 551             if (pt != null) {
 552                 return pt.toString();
 553             } else {
 554                 return "";
 555             }
 556         }
 557     }
 558 
 559     class MethodAttrInfo extends ResultInfo {
 560         public MethodAttrInfo() {
 561             this(chk.basicHandler);
 562         }
 563 
 564         public MethodAttrInfo(CheckContext checkContext) {
 565             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 566         }
 567 
 568         @Override
 569         protected boolean needsArgumentAttr(JCTree tree) {
 570             return true;
 571         }
 572 
 573         protected ResultInfo dup(Type newPt) {
 574             throw new IllegalStateException();
 575         }
 576 
 577         protected ResultInfo dup(CheckContext newContext) {
 578             return new MethodAttrInfo(newContext);
 579         }
 580 
 581         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 582             throw new IllegalStateException();
 583         }
 584 
 585         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 586             throw new IllegalStateException();
 587         }
 588 
 589         protected ResultInfo dup(CheckMode newMode) {
 590             throw new IllegalStateException();
 591         }
 592     }
 593 
 594     class RecoveryInfo extends ResultInfo {
 595 
 596         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 597             this(deferredAttrContext, Type.recoveryType);
 598         }
 599 
 600         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 601             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 602                 @Override
 603                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 604                     return deferredAttrContext;
 605                 }
 606                 @Override
 607                 public boolean compatible(Type found, Type req, Warner warn) {
 608                     return true;
 609                 }
 610                 @Override
 611                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 612                     boolean needsReport = pt == Type.recoveryType ||
 613                             (details.getDiagnosticPosition() != null &&
 614                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 615                     if (needsReport) {
 616                         chk.basicHandler.report(pos, details);
 617                     }
 618                 }
 619             });
 620         }
 621     }
 622 
 623     final ResultInfo statInfo;
 624     final ResultInfo varAssignmentInfo;
 625     final ResultInfo methodAttrInfo;
 626     final ResultInfo unknownExprInfo;
 627     final ResultInfo unknownTypeInfo;
 628     final ResultInfo unknownTypeExprInfo;
 629     final ResultInfo recoveryInfo;
 630 
 631     Type pt() {
 632         return resultInfo.pt;
 633     }
 634 
 635     KindSelector pkind() {
 636         return resultInfo.pkind;
 637     }
 638 
 639 /* ************************************************************************
 640  * Visitor methods
 641  *************************************************************************/
 642 
 643     /** Visitor argument: the current environment.
 644      */
 645     Env<AttrContext> env;
 646 
 647     /** Visitor argument: the currently expected attribution result.
 648      */
 649     ResultInfo resultInfo;
 650 
 651     /** Visitor result: the computed type.
 652      */
 653     Type result;
 654 
 655     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 656 
 657     /** Visitor method: attribute a tree, catching any completion failure
 658      *  exceptions. Return the tree's type.
 659      *
 660      *  @param tree    The tree to be visited.
 661      *  @param env     The environment visitor argument.
 662      *  @param resultInfo   The result info visitor argument.
 663      */
 664     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 665         Env<AttrContext> prevEnv = this.env;
 666         ResultInfo prevResult = this.resultInfo;
 667         try {
 668             this.env = env;
 669             this.resultInfo = resultInfo;
 670             if (resultInfo.needsArgumentAttr(tree)) {
 671                 result = argumentAttr.attribArg(tree, env);
 672             } else {
 673                 tree.accept(this);
 674             }
 675             matchBindings = matchBindingsComputer.finishBindings(tree,
 676                                                                  matchBindings);
 677             if (tree == breakTree &&
 678                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 679                 breakTreeFound(copyEnv(env));
 680             }
 681             return result;
 682         } catch (CompletionFailure ex) {
 683             tree.type = syms.errType;
 684             return chk.completionError(tree.pos(), ex);
 685         } finally {
 686             this.env = prevEnv;
 687             this.resultInfo = prevResult;
 688         }
 689     }
 690 
 691     protected void breakTreeFound(Env<AttrContext> env) {
 692         throw new BreakAttr(env);
 693     }
 694 
 695     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 696         Env<AttrContext> newEnv =
 697                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 698         if (newEnv.outer != null) {
 699             newEnv.outer = copyEnv(newEnv.outer);
 700         }
 701         return newEnv;
 702     }
 703 
 704     WriteableScope copyScope(WriteableScope sc) {
 705         WriteableScope newScope = WriteableScope.create(sc.owner);
 706         List<Symbol> elemsList = List.nil();
 707         for (Symbol sym : sc.getSymbols()) {
 708             elemsList = elemsList.prepend(sym);
 709         }
 710         for (Symbol s : elemsList) {
 711             newScope.enter(s);
 712         }
 713         return newScope;
 714     }
 715 
 716     /** Derived visitor method: attribute an expression tree.
 717      */
 718     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 719         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 720     }
 721 
 722     /** Derived visitor method: attribute an expression tree with
 723      *  no constraints on the computed type.
 724      */
 725     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 726         return attribTree(tree, env, unknownExprInfo);
 727     }
 728 
 729     /** Derived visitor method: attribute a type tree.
 730      */
 731     public Type attribType(JCTree tree, Env<AttrContext> env) {
 732         Type result = attribType(tree, env, Type.noType);
 733         return result;
 734     }
 735 
 736     /** Derived visitor method: attribute a type tree.
 737      */
 738     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 739         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 740         return result;
 741     }
 742 
 743     /** Derived visitor method: attribute a statement or definition tree.
 744      */
 745     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 746         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 747         Type result = attribTree(tree, env, statInfo);
 748         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 749         attrRecover.doRecovery();
 750         return result;
 751     }
 752 
 753     /** Attribute a list of expressions, returning a list of types.
 754      */
 755     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 756         ListBuffer<Type> ts = new ListBuffer<>();
 757         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 758             ts.append(attribExpr(l.head, env, pt));
 759         return ts.toList();
 760     }
 761 
 762     /** Attribute a list of statements, returning nothing.
 763      */
 764     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 765         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 766             attribStat(l.head, env);
 767     }
 768 
 769     /** Attribute the arguments in a method call, returning the method kind.
 770      */
 771     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 772         KindSelector kind = initialKind;
 773         for (JCExpression arg : trees) {
 774             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 775             if (argtype.hasTag(DEFERRED)) {
 776                 kind = KindSelector.of(KindSelector.POLY, kind);
 777             }
 778             argtypes.append(argtype);
 779         }
 780         return kind;
 781     }
 782 
 783     /** Attribute a type argument list, returning a list of types.
 784      *  Caller is responsible for calling checkRefTypes.
 785      */
 786     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 787         ListBuffer<Type> argtypes = new ListBuffer<>();
 788         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 789             argtypes.append(attribType(l.head, env));
 790         return argtypes.toList();
 791     }
 792 
 793     /** Attribute a type argument list, returning a list of types.
 794      *  Check that all the types are references.
 795      */
 796     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 797         List<Type> types = attribAnyTypes(trees, env);
 798         return chk.checkRefTypes(trees, types);
 799     }
 800 
 801     /**
 802      * Attribute type variables (of generic classes or methods).
 803      * Compound types are attributed later in attribBounds.
 804      * @param typarams the type variables to enter
 805      * @param env      the current environment
 806      */
 807     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 808         for (JCTypeParameter tvar : typarams) {
 809             TypeVar a = (TypeVar)tvar.type;
 810             a.tsym.flags_field |= UNATTRIBUTED;
 811             a.setUpperBound(Type.noType);
 812             if (!tvar.bounds.isEmpty()) {
 813                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 814                 for (JCExpression bound : tvar.bounds.tail)
 815                     bounds = bounds.prepend(attribType(bound, env));
 816                 types.setBounds(a, bounds.reverse());
 817             } else {
 818                 // if no bounds are given, assume a single bound of
 819                 // java.lang.Object.
 820                 types.setBounds(a, List.of(syms.objectType));
 821             }
 822             a.tsym.flags_field &= ~UNATTRIBUTED;
 823         }
 824         if (checkCyclic) {
 825             for (JCTypeParameter tvar : typarams) {
 826                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 827             }
 828         }
 829     }
 830 
 831     /**
 832      * Attribute the type references in a list of annotations.
 833      */
 834     void attribAnnotationTypes(List<JCAnnotation> annotations,
 835                                Env<AttrContext> env) {
 836         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 837             JCAnnotation a = al.head;
 838             attribType(a.annotationType, env);
 839         }
 840     }
 841 
 842     /**
 843      * Attribute a "lazy constant value".
 844      *  @param env         The env for the const value
 845      *  @param variable    The initializer for the const value
 846      *  @param type        The expected type, or null
 847      *  @see VarSymbol#setLazyConstValue
 848      */
 849     public Object attribLazyConstantValue(Env<AttrContext> env,
 850                                       JCVariableDecl variable,
 851                                       Type type) {
 852 
 853         DiagnosticPosition prevLintPos
 854                 = deferredLintHandler.setPos(variable.pos());
 855 
 856         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 857         try {
 858             Type itype = attribExpr(variable.init, env, type);
 859             if (variable.isImplicitlyTyped()) {
 860                 //fixup local variable type
 861                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 862             }
 863             if (itype.constValue() != null) {
 864                 return coerce(itype, type).constValue();
 865             } else {
 866                 return null;
 867             }
 868         } finally {
 869             log.useSource(prevSource);
 870             deferredLintHandler.setPos(prevLintPos);
 871         }
 872     }
 873 
 874     /** Attribute type reference in an `extends' or `implements' clause.
 875      *  Supertypes of anonymous inner classes are usually already attributed.
 876      *
 877      *  @param tree              The tree making up the type reference.
 878      *  @param env               The environment current at the reference.
 879      *  @param classExpected     true if only a class is expected here.
 880      *  @param interfaceExpected true if only an interface is expected here.
 881      */
 882     Type attribBase(JCTree tree,
 883                     Env<AttrContext> env,
 884                     boolean classExpected,
 885                     boolean interfaceExpected,
 886                     boolean checkExtensible) {
 887         Type t = tree.type != null ?
 888             tree.type :
 889             attribType(tree, env);
 890         try {
 891             return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 892         } catch (CompletionFailure ex) {
 893             chk.completionError(tree.pos(), ex);
 894             return t;
 895         }
 896     }
 897     Type checkBase(Type t,
 898                    JCTree tree,
 899                    Env<AttrContext> env,
 900                    boolean classExpected,
 901                    boolean interfaceExpected,
 902                    boolean checkExtensible) {
 903         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 904                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 905         if (t.tsym.isAnonymous()) {
 906             log.error(pos, Errors.CantInheritFromAnon);
 907             return types.createErrorType(t);
 908         }
 909         if (t.isErroneous())
 910             return t;
 911         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 912             // check that type variable is already visible
 913             if (t.getUpperBound() == null) {
 914                 log.error(pos, Errors.IllegalForwardRef);
 915                 return types.createErrorType(t);
 916             }
 917         } else {
 918             t = chk.checkClassType(pos, t, checkExtensible);
 919         }
 920         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 921             log.error(pos, Errors.IntfExpectedHere);
 922             // return errType is necessary since otherwise there might
 923             // be undetected cycles which cause attribution to loop
 924             return types.createErrorType(t);
 925         } else if (checkExtensible &&
 926                    classExpected &&
 927                    (t.tsym.flags() & INTERFACE) != 0) {
 928             log.error(pos, Errors.NoIntfExpectedHere);
 929             return types.createErrorType(t);
 930         }
 931         if (checkExtensible &&
 932             ((t.tsym.flags() & FINAL) != 0)) {
 933             log.error(pos,
 934                       Errors.CantInheritFromFinal(t.tsym));
 935         }
 936         chk.checkNonCyclic(pos, t);
 937         return t;
 938     }
 939 
 940     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 941         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 942         id.type = env.info.scope.owner.enclClass().type;
 943         id.sym = env.info.scope.owner.enclClass();
 944         return id.type;
 945     }
 946 
 947     public void visitClassDef(JCClassDecl tree) {
 948         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 949                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 950                         argumentAttr.withLocalCacheContext() : null);
 951         boolean ctorProloguePrev = env.info.ctorPrologue;
 952         env.info.ctorPrologue = false;
 953         try {
 954             // Local and anonymous classes have not been entered yet, so we need to
 955             // do it now.
 956             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 957                 enter.classEnter(tree, env);
 958             } else {
 959                 // If this class declaration is part of a class level annotation,
 960                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 961                 // order to simplify later steps and allow for sensible error
 962                 // messages.
 963                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 964                     enter.classEnter(tree, env);
 965             }
 966 
 967             ClassSymbol c = tree.sym;
 968             if (c == null) {
 969                 // exit in case something drastic went wrong during enter.
 970                 result = null;
 971             } else {
 972                 // make sure class has been completed:
 973                 c.complete();
 974 
 975                 // If this class appears as an anonymous class in a constructor
 976                 // prologue, disable implicit outer instance from being passed.
 977                 // (This would be an illegal access to "this before super").
 978                 if (ctorProloguePrev && env.tree.hasTag(NEWCLASS)) {
 979                     c.flags_field |= NOOUTERTHIS;
 980                 }
 981                 attribClass(tree.pos(), c);
 982                 result = tree.type = c.type;
 983             }
 984         } finally {
 985             localCacheContext.ifPresent(LocalCacheContext::leave);
 986             env.info.ctorPrologue = ctorProloguePrev;
 987         }
 988     }
 989 
 990     public void visitMethodDef(JCMethodDecl tree) {
 991         MethodSymbol m = tree.sym;
 992         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
 993 
 994         Lint lint = env.info.lint.augment(m);
 995         Lint prevLint = chk.setLint(lint);
 996         boolean ctorProloguePrev = env.info.ctorPrologue;
 997         env.info.ctorPrologue = false;
 998         MethodSymbol prevMethod = chk.setMethod(m);
 999         try {
1000             deferredLintHandler.flush(tree.pos());
1001             chk.checkDeprecatedAnnotation(tree.pos(), m);
1002 
1003 
1004             // Create a new environment with local scope
1005             // for attributing the method.
1006             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
1007             localEnv.info.lint = lint;
1008 
1009             attribStats(tree.typarams, localEnv);
1010 
1011             // If we override any other methods, check that we do so properly.
1012             // JLS ???
1013             if (m.isStatic()) {
1014                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1015             } else {
1016                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1017             }
1018             chk.checkOverride(env, tree, m);
1019 
1020             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1021                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1022             }
1023 
1024             // Enter all type parameters into the local method scope.
1025             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1026                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1027 
1028             ClassSymbol owner = env.enclClass.sym;
1029             if ((owner.flags() & ANNOTATION) != 0 &&
1030                     (tree.params.nonEmpty() ||
1031                     tree.recvparam != null))
1032                 log.error(tree.params.nonEmpty() ?
1033                         tree.params.head.pos() :
1034                         tree.recvparam.pos(),
1035                         Errors.IntfAnnotationMembersCantHaveParams);
1036 
1037             // Attribute all value parameters.
1038             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1039                 attribStat(l.head, localEnv);
1040             }
1041 
1042             chk.checkVarargsMethodDecl(localEnv, tree);
1043 
1044             // Check that type parameters are well-formed.
1045             chk.validate(tree.typarams, localEnv);
1046 
1047             // Check that result type is well-formed.
1048             if (tree.restype != null && !tree.restype.type.hasTag(VOID))
1049                 chk.validate(tree.restype, localEnv);
1050 
1051             // Check that receiver type is well-formed.
1052             if (tree.recvparam != null) {
1053                 // Use a new environment to check the receiver parameter.
1054                 // Otherwise I get "might not have been initialized" errors.
1055                 // Is there a better way?
1056                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1057                 attribType(tree.recvparam, newEnv);
1058                 chk.validate(tree.recvparam, newEnv);
1059             }
1060 
1061             // Is this method a constructor?
1062             boolean isConstructor = TreeInfo.isConstructor(tree);
1063 
1064             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1065                 // lets find if this method is an accessor
1066                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1067                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1068                 if (recordComponent.isPresent()) {
1069                     // the method is a user defined accessor lets check that everything is fine
1070                     if (!tree.sym.isPublic()) {
1071                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1072                     }
1073                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1074                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1075                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1076                     }
1077                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1078                         log.error(tree,
1079                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1080                     }
1081                     if (!tree.typarams.isEmpty()) {
1082                         log.error(tree,
1083                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1084                     }
1085                     if (tree.sym.isStatic()) {
1086                         log.error(tree,
1087                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1088                     }
1089                 }
1090 
1091                 if (isConstructor) {
1092                     // if this a constructor other than the canonical one
1093                     if ((tree.sym.flags_field & RECORD) == 0) {
1094                         if (!TreeInfo.hasConstructorCall(tree, names._this)) {
1095                             log.error(tree, Errors.NonCanonicalConstructorInvokeAnotherConstructor(env.enclClass.sym));
1096                         }
1097                     } else {
1098                         // but if it is the canonical:
1099 
1100                         /* if user generated, then it shouldn't:
1101                          *     - have an accessibility stricter than that of the record type
1102                          *     - explicitly invoke any other constructor
1103                          */
1104                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1105                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1106                                 log.error(tree,
1107                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1108                                             Errors.InvalidCanonicalConstructorInRecord(
1109                                                 Fragments.Canonical,
1110                                                 env.enclClass.sym.name,
1111                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1112                                             ) :
1113                                             Errors.InvalidCanonicalConstructorInRecord(
1114                                                     Fragments.Canonical,
1115                                                     env.enclClass.sym.name,
1116                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1117                                             )
1118                                 );
1119                             }
1120 
1121                             if (TreeInfo.hasAnyConstructorCall(tree)) {
1122                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1123                                         Fragments.Canonical, env.enclClass.sym.name,
1124                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1125                             }
1126                         }
1127 
1128                         // also we want to check that no type variables have been defined
1129                         if (!tree.typarams.isEmpty()) {
1130                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1131                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1132                         }
1133 
1134                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1135                          * record components
1136                          */
1137                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1138                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1139                         for (JCVariableDecl param: tree.params) {
1140                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1141                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1142                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1143                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1144                                         Fragments.Canonical, env.enclClass.sym.name,
1145                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1146                             }
1147                             recordComponents = recordComponents.tail;
1148                             recordFieldTypes = recordFieldTypes.tail;
1149                         }
1150                     }
1151                 }
1152             }
1153 
1154             // annotation method checks
1155             if ((owner.flags() & ANNOTATION) != 0) {
1156                 // annotation method cannot have throws clause
1157                 if (tree.thrown.nonEmpty()) {
1158                     log.error(tree.thrown.head.pos(),
1159                               Errors.ThrowsNotAllowedInIntfAnnotation);
1160                 }
1161                 // annotation method cannot declare type-parameters
1162                 if (tree.typarams.nonEmpty()) {
1163                     log.error(tree.typarams.head.pos(),
1164                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1165                 }
1166                 // validate annotation method's return type (could be an annotation type)
1167                 chk.validateAnnotationType(tree.restype);
1168                 // ensure that annotation method does not clash with members of Object/Annotation
1169                 chk.validateAnnotationMethod(tree.pos(), m);
1170             }
1171 
1172             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1173                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1174 
1175             if (tree.body == null) {
1176                 // Empty bodies are only allowed for
1177                 // abstract, native, or interface methods, or for methods
1178                 // in a retrofit signature class.
1179                 if (tree.defaultValue != null) {
1180                     if ((owner.flags() & ANNOTATION) == 0)
1181                         log.error(tree.pos(),
1182                                   Errors.DefaultAllowedInIntfAnnotationMember);
1183                 }
1184                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1185                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract);
1186             } else {
1187                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1188                     if ((owner.flags() & INTERFACE) != 0) {
1189                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1190                     } else {
1191                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1192                     }
1193                 } else if ((tree.mods.flags & NATIVE) != 0) {
1194                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1195                 }
1196                 // Add an implicit super() call unless an explicit call to
1197                 // super(...) or this(...) is given
1198                 // or we are compiling class java.lang.Object.
1199                 if (isConstructor && owner.type != syms.objectType) {
1200                     if (!TreeInfo.hasAnyConstructorCall(tree)) {
1201                         JCStatement supCall = make.at(tree.body.pos).Exec(make.Apply(List.nil(),
1202                                 make.Ident(names._super), make.Idents(List.nil())));
1203                         if (owner.isValueClass()) {
1204                             tree.body.stats = tree.body.stats.append(supCall);
1205                         } else {
1206                             tree.body.stats = tree.body.stats.prepend(supCall);
1207                         }
1208                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1209                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1210                             TreeInfo.hasConstructorCall(tree, names._super)) {
1211                         // enum constructors are not allowed to call super
1212                         // directly, so make sure there aren't any super calls
1213                         // in enum constructors, except in the compiler
1214                         // generated one.
1215                         log.error(tree.body.stats.head.pos(),
1216                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1217                     }
1218                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1219                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1220                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1221                         if (!initParamNames.equals(recordComponentNames)) {
1222                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1223                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1224                         }
1225                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1226                             log.error(tree,
1227                                     Errors.InvalidCanonicalConstructorInRecord(
1228                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1229                                             env.enclClass.sym.name,
1230                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1231                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1232                         }
1233                     }
1234                 }
1235 
1236                 // Attribute all type annotations in the body
1237                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m, null);
1238                 annotate.flush();
1239 
1240                 // Start of constructor prologue
1241                 localEnv.info.ctorPrologue = isConstructor;
1242 
1243                 // Attribute method body.
1244                 attribStat(tree.body, localEnv);
1245             }
1246 
1247             localEnv.info.scope.leave();
1248             result = tree.type = m.type;
1249         } finally {
1250             chk.setLint(prevLint);
1251             chk.setMethod(prevMethod);
1252             env.info.ctorPrologue = ctorProloguePrev;
1253         }
1254     }
1255 
1256     public void visitVarDef(JCVariableDecl tree) {
1257         // Local variables have not been entered yet, so we need to do it now:
1258         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1259             if (tree.sym != null) {
1260                 // parameters have already been entered
1261                 env.info.scope.enter(tree.sym);
1262             } else {
1263                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
1264                     if (tree.init == null) {
1265                         //cannot use 'var' without initializer
1266                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1267                         tree.vartype = make.Erroneous();
1268                     } else {
1269                         Fragment msg = canInferLocalVarType(tree);
1270                         if (msg != null) {
1271                             //cannot use 'var' with initializer which require an explicit target
1272                             //(e.g. lambda, method reference, array initializer).
1273                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1274                             tree.vartype = make.Erroneous();
1275                         }
1276                     }
1277                 }
1278                 try {
1279                     annotate.blockAnnotations();
1280                     memberEnter.memberEnter(tree, env);
1281                 } finally {
1282                     annotate.unblockAnnotations();
1283                 }
1284             }
1285         } else {
1286             if (tree.init != null) {
1287                 // Field initializer expression need to be entered.
1288                 annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym, tree.pos());
1289                 annotate.flush();
1290             }
1291         }
1292 
1293         VarSymbol v = tree.sym;
1294         Lint lint = env.info.lint.augment(v);
1295         Lint prevLint = chk.setLint(lint);
1296 
1297         // Check that the variable's declared type is well-formed.
1298         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1299                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1300                 (tree.sym.flags() & PARAMETER) != 0;
1301         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1302 
1303         try {
1304             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1305             deferredLintHandler.flush(tree.pos());
1306             chk.checkDeprecatedAnnotation(tree.pos(), v);
1307 
1308             if (tree.init != null) {
1309                 if ((v.flags_field & FINAL) == 0 ||
1310                     !memberEnter.needsLazyConstValue(tree.init)) {
1311                     // Not a compile-time constant
1312                     // Attribute initializer in a new environment
1313                     // with the declared variable as owner.
1314                     // Check that initializer conforms to variable's declared type.
1315                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
1316                     initEnv.info.lint = lint;
1317                     // In order to catch self-references, we set the variable's
1318                     // declaration position to maximal possible value, effectively
1319                     // marking the variable as undefined.
1320                     initEnv.info.enclVar = v;
1321                     attribExpr(tree.init, initEnv, v.type);
1322                     if (tree.isImplicitlyTyped()) {
1323                         //fixup local variable type
1324                         v.type = chk.checkLocalVarType(tree, tree.init.type, tree.name);
1325                     }
1326                 }
1327                 if (tree.isImplicitlyTyped()) {
1328                     setSyntheticVariableType(tree, v.type);
1329                 }
1330             }
1331             result = tree.type = v.type;
1332             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
1333                 if (isNonArgsMethodInObject(v.name)) {
1334                     log.error(tree, Errors.IllegalRecordComponentName(v));
1335                 }
1336             }
1337         }
1338         finally {
1339             chk.setLint(prevLint);
1340         }
1341     }
1342 
1343     private boolean isNonArgsMethodInObject(Name name) {
1344         for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
1345             if (s.type.getParameterTypes().isEmpty()) {
1346                 return true;
1347             }
1348         }
1349         // isValueObject is not included in Object yet so we need a work around
1350         return name == names.isValueObject;
1351     }
1352 
1353     Fragment canInferLocalVarType(JCVariableDecl tree) {
1354         LocalInitScanner lis = new LocalInitScanner();
1355         lis.scan(tree.init);
1356         return lis.badInferenceMsg;
1357     }
1358 
1359     static class LocalInitScanner extends TreeScanner {
1360         Fragment badInferenceMsg = null;
1361         boolean needsTarget = true;
1362 
1363         @Override
1364         public void visitNewArray(JCNewArray tree) {
1365             if (tree.elemtype == null && needsTarget) {
1366                 badInferenceMsg = Fragments.LocalArrayMissingTarget;
1367             }
1368         }
1369 
1370         @Override
1371         public void visitLambda(JCLambda tree) {
1372             if (needsTarget) {
1373                 badInferenceMsg = Fragments.LocalLambdaMissingTarget;
1374             }
1375         }
1376 
1377         @Override
1378         public void visitTypeCast(JCTypeCast tree) {
1379             boolean prevNeedsTarget = needsTarget;
1380             try {
1381                 needsTarget = false;
1382                 super.visitTypeCast(tree);
1383             } finally {
1384                 needsTarget = prevNeedsTarget;
1385             }
1386         }
1387 
1388         @Override
1389         public void visitReference(JCMemberReference tree) {
1390             if (needsTarget) {
1391                 badInferenceMsg = Fragments.LocalMrefMissingTarget;
1392             }
1393         }
1394 
1395         @Override
1396         public void visitNewClass(JCNewClass tree) {
1397             boolean prevNeedsTarget = needsTarget;
1398             try {
1399                 needsTarget = false;
1400                 super.visitNewClass(tree);
1401             } finally {
1402                 needsTarget = prevNeedsTarget;
1403             }
1404         }
1405 
1406         @Override
1407         public void visitApply(JCMethodInvocation tree) {
1408             boolean prevNeedsTarget = needsTarget;
1409             try {
1410                 needsTarget = false;
1411                 super.visitApply(tree);
1412             } finally {
1413                 needsTarget = prevNeedsTarget;
1414             }
1415         }
1416     }
1417 
1418     public void visitSkip(JCSkip tree) {
1419         result = null;
1420     }
1421 
1422     public void visitBlock(JCBlock tree) {
1423         if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
1424             // Block is a static or instance initializer;
1425             // let the owner of the environment be a freshly
1426             // created BLOCK-method.
1427             Symbol fakeOwner =
1428                 new MethodSymbol(tree.flags | BLOCK |
1429                     env.info.scope.owner.flags() & STRICTFP, names.empty, null,
1430                     env.info.scope.owner);
1431             final Env<AttrContext> localEnv =
1432                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
1433 
1434             if ((tree.flags & STATIC) != 0) {
1435                 localEnv.info.staticLevel++;
1436             } else {
1437                 localEnv.info.instanceInitializerBlock = true;
1438             }
1439             // Attribute all type annotations in the block
1440             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner, null);
1441             annotate.flush();
1442             attribStats(tree.stats, localEnv);
1443 
1444             {
1445                 // Store init and clinit type annotations with the ClassSymbol
1446                 // to allow output in Gen.normalizeDefs.
1447                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1448                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1449                 if ((tree.flags & STATIC) != 0) {
1450                     cs.appendClassInitTypeAttributes(tas);
1451                 } else {
1452                     cs.appendInitTypeAttributes(tas);
1453                 }
1454             }
1455         } else {
1456             // Create a new local environment with a local scope.
1457             Env<AttrContext> localEnv =
1458                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1459             try {
1460                 attribStats(tree.stats, localEnv);
1461             } finally {
1462                 localEnv.info.scope.leave();
1463             }
1464         }
1465         result = null;
1466     }
1467 
1468     public void visitDoLoop(JCDoWhileLoop tree) {
1469         attribStat(tree.body, env.dup(tree));
1470         attribExpr(tree.cond, env, syms.booleanType);
1471         handleLoopConditionBindings(matchBindings, tree, tree.body);
1472         result = null;
1473     }
1474 
1475     public void visitWhileLoop(JCWhileLoop tree) {
1476         attribExpr(tree.cond, env, syms.booleanType);
1477         MatchBindings condBindings = matchBindings;
1478         // include condition's bindings when true in the body:
1479         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1480         try {
1481             attribStat(tree.body, whileEnv.dup(tree));
1482         } finally {
1483             whileEnv.info.scope.leave();
1484         }
1485         handleLoopConditionBindings(condBindings, tree, tree.body);
1486         result = null;
1487     }
1488 
1489     public void visitForLoop(JCForLoop tree) {
1490         Env<AttrContext> loopEnv =
1491             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1492         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1493         try {
1494             attribStats(tree.init, loopEnv);
1495             if (tree.cond != null) {
1496                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1497                 // include condition's bindings when true in the body and step:
1498                 condBindings = matchBindings;
1499             }
1500             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1501             try {
1502                 bodyEnv.tree = tree; // before, we were not in loop!
1503                 attribStats(tree.step, bodyEnv);
1504                 attribStat(tree.body, bodyEnv);
1505             } finally {
1506                 bodyEnv.info.scope.leave();
1507             }
1508             result = null;
1509         }
1510         finally {
1511             loopEnv.info.scope.leave();
1512         }
1513         handleLoopConditionBindings(condBindings, tree, tree.body);
1514     }
1515 
1516     /**
1517      * Include condition's bindings when false after the loop, if cannot get out of the loop
1518      */
1519     private void handleLoopConditionBindings(MatchBindings condBindings,
1520                                              JCStatement loop,
1521                                              JCStatement loopBody) {
1522         if (condBindings.bindingsWhenFalse.nonEmpty() &&
1523             !breaksTo(env, loop, loopBody)) {
1524             addBindings2Scope(loop, condBindings.bindingsWhenFalse);
1525         }
1526     }
1527 
1528     private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
1529         preFlow(body);
1530         return flow.breaksToTree(env, loop, body, make);
1531     }
1532 
1533     /**
1534      * Add given bindings to the current scope, unless there's a break to
1535      * an immediately enclosing labeled statement.
1536      */
1537     private void addBindings2Scope(JCStatement introducingStatement,
1538                                    List<BindingSymbol> bindings) {
1539         if (bindings.isEmpty()) {
1540             return ;
1541         }
1542 
1543         var searchEnv = env;
1544         while (searchEnv.tree instanceof JCLabeledStatement labeled &&
1545                labeled.body == introducingStatement) {
1546             if (breaksTo(env, labeled, labeled.body)) {
1547                 //breaking to an immediately enclosing labeled statement
1548                 return ;
1549             }
1550             searchEnv = searchEnv.next;
1551             introducingStatement = labeled;
1552         }
1553 
1554         //include condition's body when false after the while, if cannot get out of the loop
1555         bindings.forEach(env.info.scope::enter);
1556         bindings.forEach(BindingSymbol::preserveBinding);
1557     }
1558 
1559     public void visitForeachLoop(JCEnhancedForLoop tree) {
1560         Env<AttrContext> loopEnv =
1561             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1562         try {
1563             //the Formal Parameter of a for-each loop is not in the scope when
1564             //attributing the for-each expression; we mimic this by attributing
1565             //the for-each expression first (against original scope).
1566             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1567             chk.checkNonVoid(tree.pos(), exprType);
1568             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1569             if (elemtype == null) {
1570                 // or perhaps expr implements Iterable<T>?
1571                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1572                 if (base == null) {
1573                     log.error(tree.expr.pos(),
1574                               Errors.ForeachNotApplicableToType(exprType,
1575                                                                 Fragments.TypeReqArrayOrIterable));
1576                     elemtype = types.createErrorType(exprType);
1577                 } else {
1578                     List<Type> iterableParams = base.allparams();
1579                     elemtype = iterableParams.isEmpty()
1580                         ? syms.objectType
1581                         : types.wildUpperBound(iterableParams.head);
1582 
1583                     // Check the return type of the method iterator().
1584                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1585                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1586                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1587                     if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
1588                         log.error(tree.pos(),
1589                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1590                     }
1591                 }
1592             }
1593             if (tree.var.isImplicitlyTyped()) {
1594                 Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
1595                 setSyntheticVariableType(tree.var, inferredType);
1596             }
1597             attribStat(tree.var, loopEnv);
1598             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1599             loopEnv.tree = tree; // before, we were not in loop!
1600             attribStat(tree.body, loopEnv);
1601             result = null;
1602         }
1603         finally {
1604             loopEnv.info.scope.leave();
1605         }
1606     }
1607 
1608     public void visitLabelled(JCLabeledStatement tree) {
1609         // Check that label is not used in an enclosing statement
1610         Env<AttrContext> env1 = env;
1611         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1612             if (env1.tree.hasTag(LABELLED) &&
1613                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1614                 log.error(tree.pos(),
1615                           Errors.LabelAlreadyInUse(tree.label));
1616                 break;
1617             }
1618             env1 = env1.next;
1619         }
1620 
1621         attribStat(tree.body, env.dup(tree));
1622         result = null;
1623     }
1624 
1625     public void visitSwitch(JCSwitch tree) {
1626         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1627             attribStats(c.stats, caseEnv);
1628         });
1629         result = null;
1630     }
1631 
1632     public void visitSwitchExpression(JCSwitchExpression tree) {
1633         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
1634                 PolyKind.STANDALONE : PolyKind.POLY;
1635 
1636         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
1637             //this means we are returning a poly conditional from void-compatible lambda expression
1638             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
1639             result = tree.type = types.createErrorType(resultInfo.pt);
1640             return;
1641         }
1642 
1643         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
1644                 unknownExprInfo :
1645                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
1646 
1647         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
1648         ListBuffer<Type> caseTypes = new ListBuffer<>();
1649 
1650         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1651             caseEnv.info.yieldResult = condInfo;
1652             attribStats(c.stats, caseEnv);
1653             new TreeScanner() {
1654                 @Override
1655                 public void visitYield(JCYield brk) {
1656                     if (brk.target == tree) {
1657                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
1658                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
1659                     }
1660                     super.visitYield(brk);
1661                 }
1662 
1663                 @Override public void visitClassDef(JCClassDecl tree) {}
1664                 @Override public void visitLambda(JCLambda tree) {}
1665             }.scan(c.stats);
1666         });
1667 
1668         if (tree.cases.isEmpty()) {
1669             log.error(tree.pos(),
1670                       Errors.SwitchExpressionEmpty);
1671         } else if (caseTypes.isEmpty()) {
1672             log.error(tree.pos(),
1673                       Errors.SwitchExpressionNoResultExpressions);
1674         }
1675 
1676         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
1677 
1678         result = tree.type = check(tree, owntype, KindSelector.VAL, resultInfo);
1679     }
1680     //where:
1681         CheckContext switchExpressionContext(CheckContext checkContext) {
1682             return new Check.NestedCheckContext(checkContext) {
1683                 //this will use enclosing check context to check compatibility of
1684                 //subexpression against target type; if we are in a method check context,
1685                 //depending on whether boxing is allowed, we could have incompatibilities
1686                 @Override
1687                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1688                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
1689                 }
1690             };
1691         }
1692 
1693     private void handleSwitch(JCTree switchTree,
1694                               JCExpression selector,
1695                               List<JCCase> cases,
1696                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
1697         Type seltype = attribExpr(selector, env);
1698 
1699         Env<AttrContext> switchEnv =
1700             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
1701 
1702         try {
1703             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
1704             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
1705             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
1706             boolean intSwitch = types.isAssignable(seltype, syms.intType);
1707             boolean errorPrimitiveSwitch = seltype.isPrimitive() && !intSwitch;
1708             boolean patternSwitch;
1709             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
1710                 !intSwitch && !errorPrimitiveSwitch) {
1711                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
1712                 patternSwitch = true;
1713             } else {
1714                 if (errorPrimitiveSwitch) {
1715                     log.error(selector.pos(), Errors.SelectorTypeNotAllowed(seltype));
1716                 }
1717                 patternSwitch = cases.stream()
1718                                      .flatMap(c -> c.labels.stream())
1719                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
1720                                                     TreeInfo.isNullCaseLabel(l));
1721             }
1722 
1723             // Attribute all cases and
1724             // check that there are no duplicate case labels or default clauses.
1725             Set<Object> constants = new HashSet<>(); // The set of case constants.
1726             boolean hasDefault = false;           // Is there a default label?
1727             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
1728             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
1729             boolean hasNullPattern = false;       // Is there a null pattern?
1730             CaseTree.CaseKind caseKind = null;
1731             boolean wasError = false;
1732             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
1733                 JCCase c = l.head;
1734                 if (caseKind == null) {
1735                     caseKind = c.caseKind;
1736                 } else if (caseKind != c.caseKind && !wasError) {
1737                     log.error(c.pos(),
1738                               Errors.SwitchMixingCaseTypes);
1739                     wasError = true;
1740                 }
1741                 MatchBindings currentBindings = null;
1742                 MatchBindings guardBindings = null;
1743                 for (List<JCCaseLabel> labels = c.labels; labels.nonEmpty(); labels = labels.tail) {
1744                     JCCaseLabel label = labels.head;
1745                     if (label instanceof JCConstantCaseLabel constLabel) {
1746                         JCExpression expr = constLabel.expr;
1747                         if (TreeInfo.isNull(expr)) {
1748                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
1749                             if (hasNullPattern) {
1750                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1751                             }
1752                             hasNullPattern = true;
1753                             attribExpr(expr, switchEnv, seltype);
1754                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
1755                         } else if (enumSwitch) {
1756                             Symbol sym = enumConstant(expr, seltype);
1757                             if (sym == null) {
1758                                 if (allowPatternSwitch) {
1759                                     attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1760                                     Symbol enumSym = TreeInfo.symbol(expr);
1761                                     if (enumSym == null || !enumSym.isEnum() || enumSym.kind != VAR) {
1762                                         log.error(expr.pos(), Errors.EnumLabelMustBeEnumConstant);
1763                                     } else if (!constants.add(enumSym)) {
1764                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1765                                     }
1766                                 } else {
1767                                     log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
1768                                 }
1769                             } else if (!constants.add(sym)) {
1770                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1771                             }
1772                         } else if (errorEnumSwitch) {
1773                             //error recovery: the selector is erroneous, and all the case labels
1774                             //are identifiers. This could be an enum switch - don't report resolve
1775                             //error for the case label:
1776                             var prevResolveHelper = rs.basicLogResolveHelper;
1777                             try {
1778                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
1779                                 attribExpr(expr, switchEnv, seltype);
1780                             } finally {
1781                                 rs.basicLogResolveHelper = prevResolveHelper;
1782                             }
1783                         } else {
1784                             Type pattype = attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1785                             if (!pattype.hasTag(ERROR)) {
1786                                 if (pattype.constValue() == null) {
1787                                     Symbol s = TreeInfo.symbol(expr);
1788                                     if (s != null && s.kind == TYP) {
1789                                         log.error(expr.pos(),
1790                                                   Errors.PatternExpected);
1791                                     } else if (s == null || !s.isEnum()) {
1792                                         log.error(expr.pos(),
1793                                                   (stringSwitch ? Errors.StringConstReq
1794                                                                 : intSwitch ? Errors.ConstExprReq
1795                                                                             : Errors.PatternOrEnumReq));
1796                                     } else if (!constants.add(s)) {
1797                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1798                                     }
1799                                 } else if (!stringSwitch && !intSwitch && !errorPrimitiveSwitch) {
1800                                     log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
1801                                 } else if (!constants.add(pattype.constValue())) {
1802                                     log.error(c.pos(), Errors.DuplicateCaseLabel);
1803                                 }
1804                             }
1805                         }
1806                     } else if (label instanceof JCDefaultCaseLabel def) {
1807                         if (hasDefault) {
1808                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
1809                         } else if (hasUnconditionalPattern) {
1810                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
1811                         }
1812                         hasDefault = true;
1813                         matchBindings = MatchBindingsComputer.EMPTY;
1814                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
1815                         //pattern
1816                         JCPattern pat = patternlabel.pat;
1817                         attribExpr(pat, switchEnv, seltype);
1818                         Type primaryType = TreeInfo.primaryPatternType(pat);
1819                         if (!primaryType.hasTag(TYPEVAR)) {
1820                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
1821                         }
1822                         if (!errorPrimitiveSwitch) {
1823                             checkCastablePattern(pat.pos(), seltype, primaryType);
1824                         }
1825                         Type patternType = types.erasure(primaryType);
1826                         JCExpression guard = c.guard;
1827                         if (guardBindings == null && guard != null) {
1828                             MatchBindings afterPattern = matchBindings;
1829                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
1830                             try {
1831                                 attribExpr(guard, bodyEnv, syms.booleanType);
1832                             } finally {
1833                                 bodyEnv.info.scope.leave();
1834                             }
1835 
1836                             guardBindings = matchBindings;
1837                             matchBindings = afterPattern;
1838 
1839                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
1840                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
1841                             }
1842                         }
1843                         boolean unguarded = TreeInfo.unguardedCase(c) && !pat.hasTag(RECORDPATTERN);
1844                         boolean unconditional =
1845                                 unguarded &&
1846                                 !patternType.isErroneous() &&
1847                                 types.isSubtype(types.boxedTypeOrType(types.erasure(seltype)),
1848                                                 patternType);
1849                         if (unconditional) {
1850                             if (hasUnconditionalPattern) {
1851                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
1852                             } else if (hasDefault) {
1853                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
1854                             }
1855                             hasUnconditionalPattern = true;
1856                         }
1857                         lastPatternErroneous = patternType.isErroneous();
1858                     } else {
1859                         Assert.error();
1860                     }
1861                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
1862                 }
1863 
1864                 if (guardBindings != null) {
1865                     currentBindings = matchBindingsComputer.caseGuard(c, currentBindings, guardBindings);
1866                 }
1867 
1868                 Env<AttrContext> caseEnv =
1869                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
1870                 try {
1871                     attribCase.accept(c, caseEnv);
1872                 } finally {
1873                     caseEnv.info.scope.leave();
1874                 }
1875                 addVars(c.stats, switchEnv.info.scope);
1876 
1877                 preFlow(c);
1878                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
1879             }
1880             if (patternSwitch) {
1881                 chk.checkSwitchCaseStructure(cases);
1882                 chk.checkSwitchCaseLabelDominated(cases);
1883             }
1884             if (switchTree.hasTag(SWITCH)) {
1885                 ((JCSwitch) switchTree).hasUnconditionalPattern =
1886                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1887                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
1888             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
1889                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
1890                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1891                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
1892             } else {
1893                 Assert.error(switchTree.getTag().name());
1894             }
1895         } finally {
1896             switchEnv.info.scope.leave();
1897         }
1898     }
1899     // where
1900         private ResultInfo caseLabelResultInfo(Type seltype) {
1901             return new ResultInfo(KindSelector.VAL_TYP,
1902                                   !seltype.hasTag(ERROR) ? seltype
1903                                                          : Type.noType);
1904         }
1905         /** Add any variables defined in stats to the switch scope. */
1906         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
1907             for (;stats.nonEmpty(); stats = stats.tail) {
1908                 JCTree stat = stats.head;
1909                 if (stat.hasTag(VARDEF))
1910                     switchScope.enter(((JCVariableDecl) stat).sym);
1911             }
1912         }
1913     // where
1914     /** Return the selected enumeration constant symbol, or null. */
1915     private Symbol enumConstant(JCTree tree, Type enumType) {
1916         if (tree.hasTag(IDENT)) {
1917             JCIdent ident = (JCIdent)tree;
1918             Name name = ident.name;
1919             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
1920                 if (sym.kind == VAR) {
1921                     Symbol s = ident.sym = sym;
1922                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1923                     ident.type = s.type;
1924                     return ((s.flags_field & Flags.ENUM) == 0)
1925                         ? null : s;
1926                 }
1927             }
1928         }
1929         return null;
1930     }
1931 
1932     public void visitSynchronized(JCSynchronized tree) {
1933         chk.checkIdentityType(tree.pos(), attribExpr(tree.lock, env));
1934         if (env.info.lint.isEnabled(LintCategory.SYNCHRONIZATION) && isValueBased(tree.lock.type)) {
1935             log.warning(LintCategory.SYNCHRONIZATION, tree.pos(), Warnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
1936         }
1937         attribStat(tree.body, env);
1938         result = null;
1939     }
1940         // where
1941         private boolean isValueBased(Type t) {
1942             return t != null && t.tsym != null && (t.tsym.flags() & VALUE_BASED) != 0;
1943         }
1944 
1945 
1946     public void visitTry(JCTry tree) {
1947         // Create a new local environment with a local
1948         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1949         try {
1950             boolean isTryWithResource = tree.resources.nonEmpty();
1951             // Create a nested environment for attributing the try block if needed
1952             Env<AttrContext> tryEnv = isTryWithResource ?
1953                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1954                 localEnv;
1955             try {
1956                 // Attribute resource declarations
1957                 for (JCTree resource : tree.resources) {
1958                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
1959                         @Override
1960                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
1961                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
1962                         }
1963                     };
1964                     ResultInfo twrResult =
1965                         new ResultInfo(KindSelector.VAR,
1966                                        syms.autoCloseableType,
1967                                        twrContext);
1968                     if (resource.hasTag(VARDEF)) {
1969                         attribStat(resource, tryEnv);
1970                         twrResult.check(resource, resource.type);
1971 
1972                         //check that resource type cannot throw InterruptedException
1973                         checkAutoCloseable(resource.pos(), localEnv, resource.type);
1974 
1975                         VarSymbol var = ((JCVariableDecl) resource).sym;
1976 
1977                         var.flags_field |= Flags.FINAL;
1978                         var.setData(ElementKind.RESOURCE_VARIABLE);
1979                     } else {
1980                         attribTree(resource, tryEnv, twrResult);
1981                     }
1982                 }
1983                 // Attribute body
1984                 attribStat(tree.body, tryEnv);
1985             } finally {
1986                 if (isTryWithResource)
1987                     tryEnv.info.scope.leave();
1988             }
1989 
1990             // Attribute catch clauses
1991             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
1992                 JCCatch c = l.head;
1993                 Env<AttrContext> catchEnv =
1994                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
1995                 try {
1996                     Type ctype = attribStat(c.param, catchEnv);
1997                     if (TreeInfo.isMultiCatch(c)) {
1998                         //multi-catch parameter is implicitly marked as final
1999                         c.param.sym.flags_field |= FINAL | UNION;
2000                     }
2001                     if (c.param.sym.kind == VAR) {
2002                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
2003                     }
2004                     chk.checkType(c.param.vartype.pos(),
2005                                   chk.checkClassType(c.param.vartype.pos(), ctype),
2006                                   syms.throwableType);
2007                     attribStat(c.body, catchEnv);
2008                 } finally {
2009                     catchEnv.info.scope.leave();
2010                 }
2011             }
2012 
2013             // Attribute finalizer
2014             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
2015             result = null;
2016         }
2017         finally {
2018             localEnv.info.scope.leave();
2019         }
2020     }
2021 
2022     void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
2023         if (!resource.isErroneous() &&
2024             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
2025             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
2026             Symbol close = syms.noSymbol;
2027             Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log);
2028             try {
2029                 close = rs.resolveQualifiedMethod(pos,
2030                         env,
2031                         types.skipTypeVars(resource, false),
2032                         names.close,
2033                         List.nil(),
2034                         List.nil());
2035             }
2036             finally {
2037                 log.popDiagnosticHandler(discardHandler);
2038             }
2039             if (close.kind == MTH &&
2040                     close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
2041                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
2042                     env.info.lint.isEnabled(LintCategory.TRY)) {
2043                 log.warning(LintCategory.TRY, pos, Warnings.TryResourceThrowsInterruptedExc(resource));
2044             }
2045         }
2046     }
2047 
2048     public void visitConditional(JCConditional tree) {
2049         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2050         MatchBindings condBindings = matchBindings;
2051 
2052         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2053                 isBooleanOrNumeric(env, tree)) ?
2054                 PolyKind.STANDALONE : PolyKind.POLY;
2055 
2056         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2057             //this means we are returning a poly conditional from void-compatible lambda expression
2058             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2059             result = tree.type = types.createErrorType(resultInfo.pt);
2060             return;
2061         }
2062 
2063         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2064                 unknownExprInfo :
2065                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2066 
2067 
2068         // x ? y : z
2069         // include x's bindings when true in y
2070         // include x's bindings when false in z
2071 
2072         Type truetype;
2073         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2074         try {
2075             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2076         } finally {
2077             trueEnv.info.scope.leave();
2078         }
2079 
2080         MatchBindings trueBindings = matchBindings;
2081 
2082         Type falsetype;
2083         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2084         try {
2085             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2086         } finally {
2087             falseEnv.info.scope.leave();
2088         }
2089 
2090         MatchBindings falseBindings = matchBindings;
2091 
2092         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2093                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2094                          List.of(truetype, falsetype)) : pt();
2095         if (condtype.constValue() != null &&
2096                 truetype.constValue() != null &&
2097                 falsetype.constValue() != null &&
2098                 !owntype.hasTag(NONE)) {
2099             //constant folding
2100             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2101         }
2102         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2103         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2104     }
2105     //where
2106         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2107             switch (tree.getTag()) {
2108                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2109                               ((JCLiteral)tree).typetag == BOOLEAN ||
2110                               ((JCLiteral)tree).typetag == BOT;
2111                 case LAMBDA: case REFERENCE: return false;
2112                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2113                 case CONDEXPR:
2114                     JCConditional condTree = (JCConditional)tree;
2115                     return isBooleanOrNumeric(env, condTree.truepart) &&
2116                             isBooleanOrNumeric(env, condTree.falsepart);
2117                 case APPLY:
2118                     JCMethodInvocation speculativeMethodTree =
2119                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2120                                     tree, env, unknownExprInfo,
2121                                     argumentAttr.withLocalCacheContext());
2122                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2123                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2124                             env.enclClass.type :
2125                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2126                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2127                     return primitiveOrBoxed(owntype);
2128                 case NEWCLASS:
2129                     JCExpression className =
2130                             removeClassParams.translate(((JCNewClass)tree).clazz);
2131                     JCExpression speculativeNewClassTree =
2132                             (JCExpression)deferredAttr.attribSpeculative(
2133                                     className, env, unknownTypeInfo,
2134                                     argumentAttr.withLocalCacheContext());
2135                     return primitiveOrBoxed(speculativeNewClassTree.type);
2136                 default:
2137                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2138                             argumentAttr.withLocalCacheContext()).type;
2139                     return primitiveOrBoxed(speculativeType);
2140             }
2141         }
2142         //where
2143             boolean primitiveOrBoxed(Type t) {
2144                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2145             }
2146 
2147             TreeTranslator removeClassParams = new TreeTranslator() {
2148                 @Override
2149                 public void visitTypeApply(JCTypeApply tree) {
2150                     result = translate(tree.clazz);
2151                 }
2152             };
2153 
2154         CheckContext conditionalContext(CheckContext checkContext) {
2155             return new Check.NestedCheckContext(checkContext) {
2156                 //this will use enclosing check context to check compatibility of
2157                 //subexpression against target type; if we are in a method check context,
2158                 //depending on whether boxing is allowed, we could have incompatibilities
2159                 @Override
2160                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2161                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2162                 }
2163             };
2164         }
2165 
2166         /** Compute the type of a conditional expression, after
2167          *  checking that it exists.  See JLS 15.25. Does not take into
2168          *  account the special case where condition and both arms
2169          *  are constants.
2170          *
2171          *  @param pos      The source position to be used for error
2172          *                  diagnostics.
2173          *  @param thentype The type of the expression's then-part.
2174          *  @param elsetype The type of the expression's else-part.
2175          */
2176         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2177             if (condTypes.isEmpty()) {
2178                 return syms.objectType; //TODO: how to handle?
2179             }
2180             Type first = condTypes.head;
2181             // If same type, that is the result
2182             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2183                 return first.baseType();
2184 
2185             List<Type> unboxedTypes = condTypes.stream()
2186                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2187                                                .collect(List.collector());
2188 
2189             // Otherwise, if both arms can be converted to a numeric
2190             // type, return the least numeric type that fits both arms
2191             // (i.e. return larger of the two, or return int if one
2192             // arm is short, the other is char).
2193             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2194                 // If one arm has an integer subrange type (i.e., byte,
2195                 // short, or char), and the other is an integer constant
2196                 // that fits into the subrange, return the subrange type.
2197                 for (Type type : unboxedTypes) {
2198                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2199                         continue;
2200                     }
2201                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2202                         return type.baseType();
2203                 }
2204 
2205                 for (TypeTag tag : primitiveTags) {
2206                     Type candidate = syms.typeOfTag[tag.ordinal()];
2207                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2208                         return candidate;
2209                     }
2210                 }
2211             }
2212 
2213             // Those were all the cases that could result in a primitive
2214             condTypes = condTypes.stream()
2215                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
2216                                  .collect(List.collector());
2217 
2218             for (Type type : condTypes) {
2219                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2220                     return type.baseType();
2221             }
2222 
2223             Iterator<DiagnosticPosition> posIt = positions.iterator();
2224 
2225             condTypes = condTypes.stream()
2226                                  .map(t -> chk.checkNonVoid(posIt.next(), t))
2227                                  .collect(List.collector());
2228 
2229             // both are known to be reference types.  The result is
2230             // lub(thentype,elsetype). This cannot fail, as it will
2231             // always be possible to infer "Object" if nothing better.
2232             return types.lub(condTypes.stream()
2233                         .map(t -> t.baseType())
2234                         .filter(t -> !t.hasTag(BOT))
2235                         .collect(List.collector()));
2236         }
2237 
2238     static final TypeTag[] primitiveTags = new TypeTag[]{
2239         BYTE,
2240         CHAR,
2241         SHORT,
2242         INT,
2243         LONG,
2244         FLOAT,
2245         DOUBLE,
2246         BOOLEAN,
2247     };
2248 
2249     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2250         return bindingEnv(env, env.tree, bindings);
2251     }
2252 
2253     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2254         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2255         bindings.forEach(env1.info.scope::enter);
2256         return env1;
2257     }
2258 
2259     public void visitIf(JCIf tree) {
2260         attribExpr(tree.cond, env, syms.booleanType);
2261 
2262         // if (x) { y } [ else z ]
2263         // include x's bindings when true in y
2264         // include x's bindings when false in z
2265 
2266         MatchBindings condBindings = matchBindings;
2267         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2268 
2269         try {
2270             attribStat(tree.thenpart, thenEnv);
2271         } finally {
2272             thenEnv.info.scope.leave();
2273         }
2274 
2275         preFlow(tree.thenpart);
2276         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2277         boolean aliveAfterElse;
2278 
2279         if (tree.elsepart != null) {
2280             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2281             try {
2282                 attribStat(tree.elsepart, elseEnv);
2283             } finally {
2284                 elseEnv.info.scope.leave();
2285             }
2286             preFlow(tree.elsepart);
2287             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2288         } else {
2289             aliveAfterElse = true;
2290         }
2291 
2292         chk.checkEmptyIf(tree);
2293 
2294         List<BindingSymbol> afterIfBindings = List.nil();
2295 
2296         if (aliveAfterThen && !aliveAfterElse) {
2297             afterIfBindings = condBindings.bindingsWhenTrue;
2298         } else if (aliveAfterElse && !aliveAfterThen) {
2299             afterIfBindings = condBindings.bindingsWhenFalse;
2300         }
2301 
2302         addBindings2Scope(tree, afterIfBindings);
2303 
2304         result = null;
2305     }
2306 
2307         void preFlow(JCTree tree) {
2308             attrRecover.doRecovery();
2309             new PostAttrAnalyzer() {
2310                 @Override
2311                 public void scan(JCTree tree) {
2312                     if (tree == null ||
2313                             (tree.type != null &&
2314                             tree.type == Type.stuckType)) {
2315                         //don't touch stuck expressions!
2316                         return;
2317                     }
2318                     super.scan(tree);
2319                 }
2320 
2321                 @Override
2322                 public void visitClassDef(JCClassDecl that) {
2323                     if (that.sym != null) {
2324                         // Method preFlow shouldn't visit class definitions
2325                         // that have not been entered and attributed.
2326                         // See JDK-8254557 and JDK-8203277 for more details.
2327                         super.visitClassDef(that);
2328                     }
2329                 }
2330 
2331                 @Override
2332                 public void visitLambda(JCLambda that) {
2333                     if (that.type != null) {
2334                         // Method preFlow shouldn't visit lambda expressions
2335                         // that have not been entered and attributed.
2336                         // See JDK-8254557 and JDK-8203277 for more details.
2337                         super.visitLambda(that);
2338                     }
2339                 }
2340             }.scan(tree);
2341         }
2342 
2343     public void visitExec(JCExpressionStatement tree) {
2344         //a fresh environment is required for 292 inference to work properly ---
2345         //see Infer.instantiatePolymorphicSignatureInstance()
2346         Env<AttrContext> localEnv = env.dup(tree);
2347         attribExpr(tree.expr, localEnv);
2348         result = null;
2349     }
2350 
2351     public void visitBreak(JCBreak tree) {
2352         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2353         result = null;
2354     }
2355 
2356     public void visitYield(JCYield tree) {
2357         if (env.info.yieldResult != null) {
2358             attribTree(tree.value, env, env.info.yieldResult);
2359             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2360         } else {
2361             log.error(tree.pos(), tree.value.hasTag(PARENS)
2362                     ? Errors.NoSwitchExpressionQualify
2363                     : Errors.NoSwitchExpression);
2364             attribTree(tree.value, env, unknownExprInfo);
2365         }
2366         result = null;
2367     }
2368 
2369     public void visitContinue(JCContinue tree) {
2370         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2371         result = null;
2372     }
2373     //where
2374         /** Return the target of a break, continue or yield statement,
2375          *  if it exists, report an error if not.
2376          *  Note: The target of a labelled break or continue is the
2377          *  (non-labelled) statement tree referred to by the label,
2378          *  not the tree representing the labelled statement itself.
2379          *
2380          *  @param pos     The position to be used for error diagnostics
2381          *  @param tag     The tag of the jump statement. This is either
2382          *                 Tree.BREAK or Tree.CONTINUE.
2383          *  @param label   The label of the jump statement, or null if no
2384          *                 label is given.
2385          *  @param env     The environment current at the jump statement.
2386          */
2387         private JCTree findJumpTarget(DiagnosticPosition pos,
2388                                                    JCTree.Tag tag,
2389                                                    Name label,
2390                                                    Env<AttrContext> env) {
2391             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2392 
2393             if (jumpTarget.snd != null) {
2394                 log.error(pos, jumpTarget.snd);
2395             }
2396 
2397             return jumpTarget.fst;
2398         }
2399         /** Return the target of a break or continue statement, if it exists,
2400          *  report an error if not.
2401          *  Note: The target of a labelled break or continue is the
2402          *  (non-labelled) statement tree referred to by the label,
2403          *  not the tree representing the labelled statement itself.
2404          *
2405          *  @param tag     The tag of the jump statement. This is either
2406          *                 Tree.BREAK or Tree.CONTINUE.
2407          *  @param label   The label of the jump statement, or null if no
2408          *                 label is given.
2409          *  @param env     The environment current at the jump statement.
2410          */
2411         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2412                                                                        Name label,
2413                                                                        Env<AttrContext> env) {
2414             // Search environments outwards from the point of jump.
2415             Env<AttrContext> env1 = env;
2416             JCDiagnostic.Error pendingError = null;
2417             LOOP:
2418             while (env1 != null) {
2419                 switch (env1.tree.getTag()) {
2420                     case LABELLED:
2421                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2422                         if (label == labelled.label) {
2423                             // If jump is a continue, check that target is a loop.
2424                             if (tag == CONTINUE) {
2425                                 if (!labelled.body.hasTag(DOLOOP) &&
2426                                         !labelled.body.hasTag(WHILELOOP) &&
2427                                         !labelled.body.hasTag(FORLOOP) &&
2428                                         !labelled.body.hasTag(FOREACHLOOP)) {
2429                                     pendingError = Errors.NotLoopLabel(label);
2430                                 }
2431                                 // Found labelled statement target, now go inwards
2432                                 // to next non-labelled tree.
2433                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2434                             } else {
2435                                 return Pair.of(labelled, pendingError);
2436                             }
2437                         }
2438                         break;
2439                     case DOLOOP:
2440                     case WHILELOOP:
2441                     case FORLOOP:
2442                     case FOREACHLOOP:
2443                         if (label == null) return Pair.of(env1.tree, pendingError);
2444                         break;
2445                     case SWITCH:
2446                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2447                         break;
2448                     case SWITCH_EXPRESSION:
2449                         if (tag == YIELD) {
2450                             return Pair.of(env1.tree, null);
2451                         } else if (tag == BREAK) {
2452                             pendingError = Errors.BreakOutsideSwitchExpression;
2453                         } else {
2454                             pendingError = Errors.ContinueOutsideSwitchExpression;
2455                         }
2456                         break;
2457                     case LAMBDA:
2458                     case METHODDEF:
2459                     case CLASSDEF:
2460                         break LOOP;
2461                     default:
2462                 }
2463                 env1 = env1.next;
2464             }
2465             if (label != null)
2466                 return Pair.of(null, Errors.UndefLabel(label));
2467             else if (pendingError != null)
2468                 return Pair.of(null, pendingError);
2469             else if (tag == CONTINUE)
2470                 return Pair.of(null, Errors.ContOutsideLoop);
2471             else
2472                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2473         }
2474 
2475     public void visitReturn(JCReturn tree) {
2476         // Check that there is an enclosing method which is
2477         // nested within than the enclosing class.
2478         if (env.info.returnResult == null) {
2479             log.error(tree.pos(), Errors.RetOutsideMeth);
2480         } else if (env.info.yieldResult != null) {
2481             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2482         } else if (!env.info.isLambda &&
2483                 !env.info.isNewClass &&
2484                 env.enclMethod != null &&
2485                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2486             log.error(env.enclMethod,
2487                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2488         } else {
2489             // Attribute return expression, if it exists, and check that
2490             // it conforms to result type of enclosing method.
2491             if (tree.expr != null) {
2492                 if (env.info.returnResult.pt.hasTag(VOID)) {
2493                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2494                               diags.fragment(Fragments.UnexpectedRetVal));
2495                 }
2496                 attribTree(tree.expr, env, env.info.returnResult);
2497             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2498                     !env.info.returnResult.pt.hasTag(NONE)) {
2499                 env.info.returnResult.checkContext.report(tree.pos(),
2500                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2501             }
2502         }
2503         result = null;
2504     }
2505 
2506     public void visitThrow(JCThrow tree) {
2507         Type owntype = attribExpr(tree.expr, env, Type.noType);
2508         chk.checkType(tree, owntype, syms.throwableType);
2509         result = null;
2510     }
2511 
2512     public void visitAssert(JCAssert tree) {
2513         attribExpr(tree.cond, env, syms.booleanType);
2514         if (tree.detail != null) {
2515             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2516         }
2517         result = null;
2518     }
2519 
2520      /** Visitor method for method invocations.
2521      *  NOTE: The method part of an application will have in its type field
2522      *        the return type of the method, not the method's type itself!
2523      */
2524     public void visitApply(JCMethodInvocation tree) {
2525         // The local environment of a method application is
2526         // a new environment nested in the current one.
2527         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2528 
2529         // The types of the actual method arguments.
2530         List<Type> argtypes;
2531 
2532         // The types of the actual method type arguments.
2533         List<Type> typeargtypes = null;
2534 
2535         Name methName = TreeInfo.name(tree.meth);
2536 
2537         boolean isConstructorCall =
2538             methName == names._this || methName == names._super;
2539 
2540         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2541         if (isConstructorCall) {
2542 
2543             // Attribute arguments, yielding list of argument types.
2544             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2545             argtypes = argtypesBuf.toList();
2546             typeargtypes = attribTypes(tree.typeargs, localEnv);
2547 
2548             // Done with this()/super() parameters. End of constructor prologue.
2549             env.info.ctorPrologue = false;
2550 
2551             // Variable `site' points to the class in which the called
2552             // constructor is defined.
2553             Type site = env.enclClass.sym.type;
2554             if (methName == names._super) {
2555                 if (site == syms.objectType) {
2556                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2557                     site = types.createErrorType(syms.objectType);
2558                 } else {
2559                     site = types.supertype(site);
2560                 }
2561             }
2562 
2563             if (site.hasTag(CLASS)) {
2564                 Type encl = site.getEnclosingType();
2565                 while (encl != null && encl.hasTag(TYPEVAR))
2566                     encl = encl.getUpperBound();
2567                 if (encl.hasTag(CLASS)) {
2568                     // we are calling a nested class
2569 
2570                     if (tree.meth.hasTag(SELECT)) {
2571                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2572 
2573                         // We are seeing a prefixed call, of the form
2574                         //     <expr>.super(...).
2575                         // Check that the prefix expression conforms
2576                         // to the outer instance type of the class.
2577                         chk.checkRefType(qualifier.pos(),
2578                                          attribExpr(qualifier, localEnv,
2579                                                     encl));
2580                     } else if (methName == names._super) {
2581                         // qualifier omitted; check for existence
2582                         // of an appropriate implicit qualifier.
2583                         rs.resolveImplicitThis(tree.meth.pos(),
2584                                                localEnv, site, true);
2585                     }
2586                 } else if (tree.meth.hasTag(SELECT)) {
2587                     log.error(tree.meth.pos(),
2588                               Errors.IllegalQualNotIcls(site.tsym));
2589                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2590                 }
2591 
2592                 // if we're calling a java.lang.Enum constructor,
2593                 // prefix the implicit String and int parameters
2594                 if (site.tsym == syms.enumSym)
2595                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
2596 
2597                 // Resolve the called constructor under the assumption
2598                 // that we are referring to a superclass instance of the
2599                 // current instance (JLS ???).
2600                 boolean selectSuperPrev = localEnv.info.selectSuper;
2601                 localEnv.info.selectSuper = true;
2602                 localEnv.info.pendingResolutionPhase = null;
2603                 Symbol sym = rs.resolveConstructor(
2604                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
2605                 localEnv.info.selectSuper = selectSuperPrev;
2606 
2607                 // Set method symbol to resolved constructor...
2608                 TreeInfo.setSymbol(tree.meth, sym);
2609 
2610                 // ...and check that it is legal in the current context.
2611                 // (this will also set the tree's type)
2612                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2613                 checkId(tree.meth, site, sym, localEnv,
2614                         new ResultInfo(kind, mpt));
2615             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
2616                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2617             }
2618             // Otherwise, `site' is an error type and we do nothing
2619             result = tree.type = syms.voidType;
2620         } else {
2621             // Otherwise, we are seeing a regular method call.
2622             // Attribute the arguments, yielding list of argument types, ...
2623             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2624             argtypes = argtypesBuf.toList();
2625             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
2626 
2627             // ... and attribute the method using as a prototype a methodtype
2628             // whose formal argument types is exactly the list of actual
2629             // arguments (this will also set the method symbol).
2630             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2631             localEnv.info.pendingResolutionPhase = null;
2632             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
2633 
2634             // Compute the result type.
2635             Type restype = mtype.getReturnType();
2636             if (restype.hasTag(WILDCARD))
2637                 throw new AssertionError(mtype);
2638 
2639             Type qualifier = (tree.meth.hasTag(SELECT))
2640                     ? ((JCFieldAccess) tree.meth).selected.type
2641                     : env.enclClass.sym.type;
2642             Symbol msym = TreeInfo.symbol(tree.meth);
2643             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
2644 
2645             chk.checkRefTypes(tree.typeargs, typeargtypes);
2646 
2647             // Check that value of resulting type is admissible in the
2648             // current context.  Also, capture the return type
2649             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
2650             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
2651         }
2652         chk.validate(tree.typeargs, localEnv);
2653     }
2654     //where
2655         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
2656             if (msym != null &&
2657                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
2658                     methodName == names.getClass &&
2659                     argtypes.isEmpty()) {
2660                 // as a special case, x.getClass() has type Class<? extends |X|>
2661                 return new ClassType(restype.getEnclosingType(),
2662                         List.of(new WildcardType(types.erasure(qualifierType.baseType()),
2663                                 BoundKind.EXTENDS,
2664                                 syms.boundClass)),
2665                         restype.tsym,
2666                         restype.getMetadata());
2667             } else if (msym != null &&
2668                     msym.owner == syms.arrayClass &&
2669                     methodName == names.clone &&
2670                     types.isArray(qualifierType)) {
2671                 // as a special case, array.clone() has a result that is
2672                 // the same as static type of the array being cloned
2673                 return qualifierType;
2674             } else {
2675                 return restype;
2676             }
2677         }
2678 
2679         /** Obtain a method type with given argument types.
2680          */
2681         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
2682             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
2683             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
2684         }
2685 
2686     public void visitNewClass(final JCNewClass tree) {
2687         Type owntype = types.createErrorType(tree.type);
2688 
2689         // The local environment of a class creation is
2690         // a new environment nested in the current one.
2691         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2692 
2693         // The anonymous inner class definition of the new expression,
2694         // if one is defined by it.
2695         JCClassDecl cdef = tree.def;
2696 
2697         // If enclosing class is given, attribute it, and
2698         // complete class name to be fully qualified
2699         JCExpression clazz = tree.clazz; // Class field following new
2700         JCExpression clazzid;            // Identifier in class field
2701         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
2702         annoclazzid = null;
2703 
2704         if (clazz.hasTag(TYPEAPPLY)) {
2705             clazzid = ((JCTypeApply) clazz).clazz;
2706             if (clazzid.hasTag(ANNOTATED_TYPE)) {
2707                 annoclazzid = (JCAnnotatedType) clazzid;
2708                 clazzid = annoclazzid.underlyingType;
2709             }
2710         } else {
2711             if (clazz.hasTag(ANNOTATED_TYPE)) {
2712                 annoclazzid = (JCAnnotatedType) clazz;
2713                 clazzid = annoclazzid.underlyingType;
2714             } else {
2715                 clazzid = clazz;
2716             }
2717         }
2718 
2719         JCExpression clazzid1 = clazzid; // The same in fully qualified form
2720 
2721         if (tree.encl != null) {
2722             // We are seeing a qualified new, of the form
2723             //    <expr>.new C <...> (...) ...
2724             // In this case, we let clazz stand for the name of the
2725             // allocated class C prefixed with the type of the qualifier
2726             // expression, so that we can
2727             // resolve it with standard techniques later. I.e., if
2728             // <expr> has type T, then <expr>.new C <...> (...)
2729             // yields a clazz T.C.
2730             Type encltype = chk.checkRefType(tree.encl.pos(),
2731                                              attribExpr(tree.encl, env));
2732             // TODO 308: in <expr>.new C, do we also want to add the type annotations
2733             // from expr to the combined type, or not? Yes, do this.
2734             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
2735                                                  ((JCIdent) clazzid).name);
2736 
2737             EndPosTable endPosTable = this.env.toplevel.endPositions;
2738             endPosTable.storeEnd(clazzid1, clazzid.getEndPosition(endPosTable));
2739             if (clazz.hasTag(ANNOTATED_TYPE)) {
2740                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
2741                 List<JCAnnotation> annos = annoType.annotations;
2742 
2743                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
2744                     clazzid1 = make.at(tree.pos).
2745                         TypeApply(clazzid1,
2746                                   ((JCTypeApply) clazz).arguments);
2747                 }
2748 
2749                 clazzid1 = make.at(tree.pos).
2750                     AnnotatedType(annos, clazzid1);
2751             } else if (clazz.hasTag(TYPEAPPLY)) {
2752                 clazzid1 = make.at(tree.pos).
2753                     TypeApply(clazzid1,
2754                               ((JCTypeApply) clazz).arguments);
2755             }
2756 
2757             clazz = clazzid1;
2758         }
2759 
2760         // Attribute clazz expression and store
2761         // symbol + type back into the attributed tree.
2762         Type clazztype;
2763 
2764         try {
2765             env.info.isNewClass = true;
2766             clazztype = TreeInfo.isEnumInit(env.tree) ?
2767                 attribIdentAsEnumType(env, (JCIdent)clazz) :
2768                 attribType(clazz, env);
2769         } finally {
2770             env.info.isNewClass = false;
2771         }
2772 
2773         clazztype = chk.checkDiamond(tree, clazztype);
2774         chk.validate(clazz, localEnv);
2775         if (tree.encl != null) {
2776             // We have to work in this case to store
2777             // symbol + type back into the attributed tree.
2778             tree.clazz.type = clazztype;
2779             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
2780             clazzid.type = ((JCIdent) clazzid).sym.type;
2781             if (annoclazzid != null) {
2782                 annoclazzid.type = clazzid.type;
2783             }
2784             if (!clazztype.isErroneous()) {
2785                 if (cdef != null && clazztype.tsym.isInterface()) {
2786                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
2787                 } else if (clazztype.tsym.isStatic()) {
2788                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
2789                 }
2790             }
2791         } else if (!clazztype.tsym.isInterface() &&
2792                    clazztype.getEnclosingType().hasTag(CLASS)) {
2793             // Check for the existence of an apropos outer instance
2794             rs.resolveImplicitThis(tree.pos(), env, clazztype);
2795         }
2796 
2797         // Attribute constructor arguments.
2798         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2799         final KindSelector pkind =
2800             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2801         List<Type> argtypes = argtypesBuf.toList();
2802         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
2803 
2804         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
2805             // Enums may not be instantiated except implicitly
2806             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
2807                 (!env.tree.hasTag(VARDEF) ||
2808                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
2809                  ((JCVariableDecl) env.tree).init != tree))
2810                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
2811 
2812             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
2813                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
2814             boolean skipNonDiamondPath = false;
2815             // Check that class is not abstract
2816             if (cdef == null && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
2817                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
2818                 log.error(tree.pos(),
2819                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
2820                 skipNonDiamondPath = true;
2821             } else if (cdef != null && clazztype.tsym.isInterface()) {
2822                 // Check that no constructor arguments are given to
2823                 // anonymous classes implementing an interface
2824                 if (!argtypes.isEmpty())
2825                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
2826 
2827                 if (!typeargtypes.isEmpty())
2828                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
2829 
2830                 // Error recovery: pretend no arguments were supplied.
2831                 argtypes = List.nil();
2832                 typeargtypes = List.nil();
2833                 skipNonDiamondPath = true;
2834             }
2835             if (TreeInfo.isDiamond(tree)) {
2836                 ClassType site = new ClassType(clazztype.getEnclosingType(),
2837                             clazztype.tsym.type.getTypeArguments(),
2838                                                clazztype.tsym,
2839                                                clazztype.getMetadata());
2840 
2841                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
2842                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
2843                 diamondEnv.info.pendingResolutionPhase = null;
2844 
2845                 //if the type of the instance creation expression is a class type
2846                 //apply method resolution inference (JLS 15.12.2.7). The return type
2847                 //of the resolved constructor will be a partially instantiated type
2848                 Symbol constructor = rs.resolveDiamond(tree.pos(),
2849                             diamondEnv,
2850                             site,
2851                             argtypes,
2852                             typeargtypes);
2853                 tree.constructor = constructor.baseSymbol();
2854 
2855                 final TypeSymbol csym = clazztype.tsym;
2856                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
2857                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
2858                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
2859                 constructorType = checkId(tree, site,
2860                         constructor,
2861                         diamondEnv,
2862                         diamondResult);
2863 
2864                 tree.clazz.type = types.createErrorType(clazztype);
2865                 if (!constructorType.isErroneous()) {
2866                     tree.clazz.type = clazz.type = constructorType.getReturnType();
2867                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
2868                 }
2869                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
2870             }
2871 
2872             // Resolve the called constructor under the assumption
2873             // that we are referring to a superclass instance of the
2874             // current instance (JLS ???).
2875             else if (!skipNonDiamondPath) {
2876                 //the following code alters some of the fields in the current
2877                 //AttrContext - hence, the current context must be dup'ed in
2878                 //order to avoid downstream failures
2879                 Env<AttrContext> rsEnv = localEnv.dup(tree);
2880                 rsEnv.info.selectSuper = cdef != null;
2881                 rsEnv.info.pendingResolutionPhase = null;
2882                 tree.constructor = rs.resolveConstructor(
2883                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
2884                 if (cdef == null) { //do not check twice!
2885                     tree.constructorType = checkId(tree,
2886                             clazztype,
2887                             tree.constructor,
2888                             rsEnv,
2889                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
2890                     if (rsEnv.info.lastResolveVarargs())
2891                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
2892                 }
2893             }
2894 
2895             if (cdef != null) {
2896                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
2897                 return;
2898             }
2899 
2900             if (tree.constructor != null && tree.constructor.kind == MTH)
2901                 owntype = clazztype;
2902         }
2903         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2904         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2905         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
2906             //we need to wait for inference to finish and then replace inference vars in the constructor type
2907             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
2908                     instantiatedContext -> {
2909                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2910                     });
2911         }
2912         chk.validate(tree.typeargs, localEnv);
2913     }
2914 
2915         // where
2916         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
2917                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
2918                                                    List<Type> argtypes, List<Type> typeargtypes,
2919                                                    KindSelector pkind) {
2920             // We are seeing an anonymous class instance creation.
2921             // In this case, the class instance creation
2922             // expression
2923             //
2924             //    E.new <typeargs1>C<typargs2>(args) { ... }
2925             //
2926             // is represented internally as
2927             //
2928             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
2929             //
2930             // This expression is then *transformed* as follows:
2931             //
2932             // (1) add an extends or implements clause
2933             // (2) add a constructor.
2934             //
2935             // For instance, if C is a class, and ET is the type of E,
2936             // the expression
2937             //
2938             //    E.new <typeargs1>C<typargs2>(args) { ... }
2939             //
2940             // is translated to (where X is a fresh name and typarams is the
2941             // parameter list of the super constructor):
2942             //
2943             //   new <typeargs1>X(<*nullchk*>E, args) where
2944             //     X extends C<typargs2> {
2945             //       <typarams> X(ET e, args) {
2946             //         e.<typeargs1>super(args)
2947             //       }
2948             //       ...
2949             //     }
2950             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2951             Type enclType = clazztype.getEnclosingType();
2952             if (enclType != null &&
2953                     enclType.hasTag(CLASS) &&
2954                     !chk.checkDenotable((ClassType)enclType)) {
2955                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
2956             }
2957             final boolean isDiamond = TreeInfo.isDiamond(tree);
2958             if (isDiamond
2959                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
2960                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
2961                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
2962                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
2963                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
2964                         instantiatedContext -> {
2965                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2966                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
2967                             ResultInfo prevResult = this.resultInfo;
2968                             try {
2969                                 this.resultInfo = resultInfoForClassDefinition;
2970                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
2971                                         dupLocalEnv, argtypes, typeargtypes, pkind);
2972                             } finally {
2973                                 this.resultInfo = prevResult;
2974                             }
2975                         });
2976             } else {
2977                 if (isDiamond && clazztype.hasTag(CLASS)) {
2978                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
2979                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
2980                         // One or more types inferred in the previous steps is non-denotable.
2981                         Fragment fragment = Diamond(clazztype.tsym);
2982                         log.error(tree.clazz.pos(),
2983                                 Errors.CantApplyDiamond1(
2984                                         fragment,
2985                                         invalidDiamondArgs.size() > 1 ?
2986                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
2987                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
2988                     }
2989                     // For <>(){}, inferred types must also be accessible.
2990                     for (Type t : clazztype.getTypeArguments()) {
2991                         rs.checkAccessibleType(env, t);
2992                     }
2993                 }
2994 
2995                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
2996                 // false for isInterface call even when the original type is an interface.
2997                 boolean implementing = clazztype.tsym.isInterface() ||
2998                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
2999                         clazztype.getOriginalType().tsym.isInterface();
3000 
3001                 if (implementing) {
3002                     cdef.implementing = List.of(clazz);
3003                 } else {
3004                     cdef.extending = clazz;
3005                 }
3006 
3007                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3008                     rs.isSerializable(clazztype)) {
3009                     localEnv.info.isSerializable = true;
3010                 }
3011 
3012                 attribStat(cdef, localEnv);
3013 
3014                 List<Type> finalargtypes;
3015                 // If an outer instance is given,
3016                 // prefix it to the constructor arguments
3017                 // and delete it from the new expression
3018                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
3019                     finalargtypes = argtypes.prepend(tree.encl.type);
3020                 } else {
3021                     finalargtypes = argtypes;
3022                 }
3023 
3024                 // Reassign clazztype and recompute constructor. As this necessarily involves
3025                 // another attribution pass for deferred types in the case of <>, replicate
3026                 // them. Original arguments have right decorations already.
3027                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3028                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3029                 }
3030 
3031                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3032                                                     : cdef.sym.type;
3033                 Symbol sym = tree.constructor = rs.resolveConstructor(
3034                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3035                 Assert.check(!sym.kind.isResolutionError());
3036                 tree.constructor = sym;
3037                 tree.constructorType = checkId(tree,
3038                         clazztype,
3039                         tree.constructor,
3040                         localEnv,
3041                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3042             }
3043             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3044                                 clazztype : types.createErrorType(tree.type);
3045             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3046             chk.validate(tree.typeargs, localEnv);
3047         }
3048 
3049         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3050             return new Check.NestedCheckContext(checkContext) {
3051                 @Override
3052                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3053                     enclosingContext.report(clazz.clazz,
3054                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3055                 }
3056             };
3057         }
3058 
3059     /** Make an attributed null check tree.
3060      */
3061     public JCExpression makeNullCheck(JCExpression arg) {
3062         // optimization: new Outer() can never be null; skip null check
3063         if (arg.getTag() == NEWCLASS)
3064             return arg;
3065         // optimization: X.this is never null; skip null check
3066         Name name = TreeInfo.name(arg);
3067         if (name == names._this || name == names._super) return arg;
3068 
3069         JCTree.Tag optag = NULLCHK;
3070         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3071         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3072         tree.type = arg.type;
3073         return tree;
3074     }
3075 
3076     public void visitNewArray(JCNewArray tree) {
3077         Type owntype = types.createErrorType(tree.type);
3078         Env<AttrContext> localEnv = env.dup(tree);
3079         Type elemtype;
3080         if (tree.elemtype != null) {
3081             elemtype = attribType(tree.elemtype, localEnv);
3082             chk.validate(tree.elemtype, localEnv);
3083             owntype = elemtype;
3084             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3085                 attribExpr(l.head, localEnv, syms.intType);
3086                 owntype = new ArrayType(owntype, syms.arrayClass);
3087             }
3088         } else {
3089             // we are seeing an untyped aggregate { ... }
3090             // this is allowed only if the prototype is an array
3091             if (pt().hasTag(ARRAY)) {
3092                 elemtype = types.elemtype(pt());
3093             } else {
3094                 if (!pt().hasTag(ERROR) &&
3095                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3096                     log.error(tree.pos(),
3097                               Errors.IllegalInitializerForType(pt()));
3098                 }
3099                 elemtype = types.createErrorType(pt());
3100             }
3101         }
3102         if (tree.elems != null) {
3103             attribExprs(tree.elems, localEnv, elemtype);
3104             owntype = new ArrayType(elemtype, syms.arrayClass);
3105         }
3106         if (!types.isReifiable(elemtype))
3107             log.error(tree.pos(), Errors.GenericArrayCreation);
3108         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3109     }
3110 
3111     /*
3112      * A lambda expression can only be attributed when a target-type is available.
3113      * In addition, if the target-type is that of a functional interface whose
3114      * descriptor contains inference variables in argument position the lambda expression
3115      * is 'stuck' (see DeferredAttr).
3116      */
3117     @Override
3118     public void visitLambda(final JCLambda that) {
3119         boolean wrongContext = false;
3120         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3121             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3122                 //lambda only allowed in assignment or method invocation/cast context
3123                 log.error(that.pos(), Errors.UnexpectedLambda);
3124             }
3125             resultInfo = recoveryInfo;
3126             wrongContext = true;
3127         }
3128         //create an environment for attribution of the lambda expression
3129         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3130         boolean needsRecovery =
3131                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3132         try {
3133             if (needsRecovery && rs.isSerializable(pt())) {
3134                 localEnv.info.isSerializable = true;
3135                 localEnv.info.isSerializableLambda = true;
3136             }
3137             List<Type> explicitParamTypes = null;
3138             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3139                 //attribute lambda parameters
3140                 attribStats(that.params, localEnv);
3141                 explicitParamTypes = TreeInfo.types(that.params);
3142             }
3143 
3144             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3145             Type currentTarget = targetInfo.target;
3146             Type lambdaType = targetInfo.descriptor;
3147 
3148             if (currentTarget.isErroneous()) {
3149                 result = that.type = currentTarget;
3150                 return;
3151             }
3152 
3153             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3154 
3155             if (lambdaType.hasTag(FORALL)) {
3156                 //lambda expression target desc cannot be a generic method
3157                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3158                                                                     kindName(currentTarget.tsym),
3159                                                                     currentTarget.tsym);
3160                 resultInfo.checkContext.report(that, diags.fragment(msg));
3161                 result = that.type = types.createErrorType(pt());
3162                 return;
3163             }
3164 
3165             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3166                 //add param type info in the AST
3167                 List<Type> actuals = lambdaType.getParameterTypes();
3168                 List<JCVariableDecl> params = that.params;
3169 
3170                 boolean arityMismatch = false;
3171 
3172                 while (params.nonEmpty()) {
3173                     if (actuals.isEmpty()) {
3174                         //not enough actuals to perform lambda parameter inference
3175                         arityMismatch = true;
3176                     }
3177                     //reset previously set info
3178                     Type argType = arityMismatch ?
3179                             syms.errType :
3180                             actuals.head;
3181                     if (params.head.isImplicitlyTyped()) {
3182                         setSyntheticVariableType(params.head, argType);
3183                     }
3184                     params.head.sym = null;
3185                     actuals = actuals.isEmpty() ?
3186                             actuals :
3187                             actuals.tail;
3188                     params = params.tail;
3189                 }
3190 
3191                 //attribute lambda parameters
3192                 attribStats(that.params, localEnv);
3193 
3194                 if (arityMismatch) {
3195                     resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3196                         result = that.type = types.createErrorType(currentTarget);
3197                         return;
3198                 }
3199             }
3200 
3201             //from this point on, no recovery is needed; if we are in assignment context
3202             //we will be able to attribute the whole lambda body, regardless of errors;
3203             //if we are in a 'check' method context, and the lambda is not compatible
3204             //with the target-type, it will be recovered anyway in Attr.checkId
3205             needsRecovery = false;
3206 
3207             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3208                     lambdaBodyResult(that, lambdaType, resultInfo);
3209 
3210             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3211                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3212             } else {
3213                 JCBlock body = (JCBlock)that.body;
3214                 if (body == breakTree &&
3215                         resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3216                     breakTreeFound(copyEnv(localEnv));
3217                 }
3218                 attribStats(body.stats, localEnv);
3219             }
3220 
3221             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3222 
3223             boolean isSpeculativeRound =
3224                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3225 
3226             preFlow(that);
3227             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3228 
3229             that.type = currentTarget; //avoids recovery at this stage
3230             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
3231 
3232             if (!isSpeculativeRound) {
3233                 //add thrown types as bounds to the thrown types free variables if needed:
3234                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3235                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3236                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3237                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3238                     }
3239                 }
3240 
3241                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3242             }
3243             result = wrongContext ? that.type = types.createErrorType(pt())
3244                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3245         } catch (Types.FunctionDescriptorLookupError ex) {
3246             JCDiagnostic cause = ex.getDiagnostic();
3247             resultInfo.checkContext.report(that, cause);
3248             result = that.type = types.createErrorType(pt());
3249             return;
3250         } catch (CompletionFailure cf) {
3251             chk.completionError(that.pos(), cf);
3252         } catch (Throwable t) {
3253             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3254             //as that would likely cause the same exception again.
3255             needsRecovery = false;
3256             throw t;
3257         } finally {
3258             localEnv.info.scope.leave();
3259             if (needsRecovery) {
3260                 Type prevResult = result;
3261                 try {
3262                     attribTree(that, env, recoveryInfo);
3263                 } finally {
3264                     if (result == Type.recoveryType) {
3265                         result = prevResult;
3266                     }
3267                 }
3268             }
3269         }
3270     }
3271     //where
3272         class TargetInfo {
3273             Type target;
3274             Type descriptor;
3275 
3276             public TargetInfo(Type target, Type descriptor) {
3277                 this.target = target;
3278                 this.descriptor = descriptor;
3279             }
3280         }
3281 
3282         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3283             Type lambdaType;
3284             Type currentTarget = resultInfo.pt;
3285             if (resultInfo.pt != Type.recoveryType) {
3286                 /* We need to adjust the target. If the target is an
3287                  * intersection type, for example: SAM & I1 & I2 ...
3288                  * the target will be updated to SAM
3289                  */
3290                 currentTarget = targetChecker.visit(currentTarget, that);
3291                 if (!currentTarget.isIntersection()) {
3292                     if (explicitParamTypes != null) {
3293                         currentTarget = infer.instantiateFunctionalInterface(that,
3294                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3295                     }
3296                     currentTarget = types.removeWildcards(currentTarget);
3297                     lambdaType = types.findDescriptorType(currentTarget);
3298                 } else {
3299                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3300                     ListBuffer<Type> components = new ListBuffer<>();
3301                     for (Type bound : ict.getExplicitComponents()) {
3302                         if (explicitParamTypes != null) {
3303                             try {
3304                                 bound = infer.instantiateFunctionalInterface(that,
3305                                         bound, explicitParamTypes, resultInfo.checkContext);
3306                             } catch (FunctionDescriptorLookupError t) {
3307                                 // do nothing
3308                             }
3309                         }
3310                         bound = types.removeWildcards(bound);
3311                         components.add(bound);
3312                     }
3313                     currentTarget = types.makeIntersectionType(components.toList());
3314                     currentTarget.tsym.flags_field |= INTERFACE;
3315                     lambdaType = types.findDescriptorType(currentTarget);
3316                 }
3317 
3318             } else {
3319                 currentTarget = Type.recoveryType;
3320                 lambdaType = fallbackDescriptorType(that);
3321             }
3322             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3323                 //lambda expression target desc cannot be a generic method
3324                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3325                                                                     kindName(currentTarget.tsym),
3326                                                                     currentTarget.tsym);
3327                 resultInfo.checkContext.report(that, diags.fragment(msg));
3328                 currentTarget = types.createErrorType(pt());
3329             }
3330             return new TargetInfo(currentTarget, lambdaType);
3331         }
3332 
3333         void preFlow(JCLambda tree) {
3334             attrRecover.doRecovery();
3335             new PostAttrAnalyzer() {
3336                 @Override
3337                 public void scan(JCTree tree) {
3338                     if (tree == null ||
3339                             (tree.type != null &&
3340                             tree.type == Type.stuckType)) {
3341                         //don't touch stuck expressions!
3342                         return;
3343                     }
3344                     super.scan(tree);
3345                 }
3346 
3347                 @Override
3348                 public void visitClassDef(JCClassDecl that) {
3349                     // or class declaration trees!
3350                 }
3351 
3352                 public void visitLambda(JCLambda that) {
3353                     // or lambda expressions!
3354                 }
3355             }.scan(tree.body);
3356         }
3357 
3358         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3359 
3360             @Override
3361             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3362                 return t.isIntersection() ?
3363                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3364             }
3365 
3366             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3367                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3368                 return ict;
3369             }
3370 
3371             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3372                 ListBuffer<Type> targs = new ListBuffer<>();
3373                 ListBuffer<Type> supertypes = new ListBuffer<>();
3374                 for (Type i : ict.interfaces_field) {
3375                     if (i.isParameterized()) {
3376                         targs.appendList(i.tsym.type.allparams());
3377                     }
3378                     supertypes.append(i.tsym.type);
3379                 }
3380                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3381                 notionalIntf.allparams_field = targs.toList();
3382                 notionalIntf.tsym.flags_field |= INTERFACE;
3383                 return notionalIntf.tsym;
3384             }
3385         };
3386 
3387         private Type fallbackDescriptorType(JCExpression tree) {
3388             switch (tree.getTag()) {
3389                 case LAMBDA:
3390                     JCLambda lambda = (JCLambda)tree;
3391                     List<Type> argtypes = List.nil();
3392                     for (JCVariableDecl param : lambda.params) {
3393                         argtypes = param.vartype != null && param.vartype.type != null ?
3394                                 argtypes.append(param.vartype.type) :
3395                                 argtypes.append(syms.errType);
3396                     }
3397                     return new MethodType(argtypes, Type.recoveryType,
3398                             List.of(syms.throwableType), syms.methodClass);
3399                 case REFERENCE:
3400                     return new MethodType(List.nil(), Type.recoveryType,
3401                             List.of(syms.throwableType), syms.methodClass);
3402                 default:
3403                     Assert.error("Cannot get here!");
3404             }
3405             return null;
3406         }
3407 
3408         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3409                 final InferenceContext inferenceContext, final Type... ts) {
3410             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3411         }
3412 
3413         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3414                 final InferenceContext inferenceContext, final List<Type> ts) {
3415             if (inferenceContext.free(ts)) {
3416                 inferenceContext.addFreeTypeListener(ts,
3417                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3418             } else {
3419                 for (Type t : ts) {
3420                     rs.checkAccessibleType(env, t);
3421                 }
3422             }
3423         }
3424 
3425         /**
3426          * Lambda/method reference have a special check context that ensures
3427          * that i.e. a lambda return type is compatible with the expected
3428          * type according to both the inherited context and the assignment
3429          * context.
3430          */
3431         class FunctionalReturnContext extends Check.NestedCheckContext {
3432 
3433             FunctionalReturnContext(CheckContext enclosingContext) {
3434                 super(enclosingContext);
3435             }
3436 
3437             @Override
3438             public boolean compatible(Type found, Type req, Warner warn) {
3439                 //return type must be compatible in both current context and assignment context
3440                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3441             }
3442 
3443             @Override
3444             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3445                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3446             }
3447         }
3448 
3449         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3450 
3451             JCExpression expr;
3452             boolean expStmtExpected;
3453 
3454             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3455                 super(enclosingContext);
3456                 this.expr = expr;
3457             }
3458 
3459             @Override
3460             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3461                 if (expStmtExpected) {
3462                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3463                 } else {
3464                     super.report(pos, details);
3465                 }
3466             }
3467 
3468             @Override
3469             public boolean compatible(Type found, Type req, Warner warn) {
3470                 //a void return is compatible with an expression statement lambda
3471                 if (req.hasTag(VOID)) {
3472                     expStmtExpected = true;
3473                     return TreeInfo.isExpressionStatement(expr);
3474                 } else {
3475                     return super.compatible(found, req, warn);
3476                 }
3477             }
3478         }
3479 
3480         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3481             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3482                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3483                     new FunctionalReturnContext(resultInfo.checkContext);
3484 
3485             return descriptor.getReturnType() == Type.recoveryType ?
3486                     recoveryInfo :
3487                     new ResultInfo(KindSelector.VAL,
3488                             descriptor.getReturnType(), funcContext);
3489         }
3490 
3491         /**
3492         * Lambda compatibility. Check that given return types, thrown types, parameter types
3493         * are compatible with the expected functional interface descriptor. This means that:
3494         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3495         * types must be compatible with the return type of the expected descriptor.
3496         */
3497         void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
3498             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3499 
3500             //return values have already been checked - but if lambda has no return
3501             //values, we must ensure that void/value compatibility is correct;
3502             //this amounts at checking that, if a lambda body can complete normally,
3503             //the descriptor's return type must be void
3504             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3505                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3506                 Fragment msg =
3507                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3508                 checkContext.report(tree,
3509                                     diags.fragment(msg));
3510             }
3511 
3512             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3513             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3514                 checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3515             }
3516         }
3517 
3518         /* Map to hold 'fake' clinit methods. If a lambda is used to initialize a
3519          * static field and that lambda has type annotations, these annotations will
3520          * also be stored at these fake clinit methods.
3521          *
3522          * LambdaToMethod also use fake clinit methods so they can be reused.
3523          * Also as LTM is a phase subsequent to attribution, the methods from
3524          * clinits can be safely removed by LTM to save memory.
3525          */
3526         private Map<ClassSymbol, MethodSymbol> clinits = new HashMap<>();
3527 
3528         public MethodSymbol removeClinit(ClassSymbol sym) {
3529             return clinits.remove(sym);
3530         }
3531 
3532         /* This method returns an environment to be used to attribute a lambda
3533          * expression.
3534          *
3535          * The owner of this environment is a method symbol. If the current owner
3536          * is not a method, for example if the lambda is used to initialize
3537          * a field, then if the field is:
3538          *
3539          * - an instance field, we use the first constructor.
3540          * - a static field, we create a fake clinit method.
3541          */
3542         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3543             Env<AttrContext> lambdaEnv;
3544             Symbol owner = env.info.scope.owner;
3545             if (owner.kind == VAR && owner.owner.kind == TYP) {
3546                 //field initializer
3547                 ClassSymbol enclClass = owner.enclClass();
3548                 Symbol newScopeOwner = env.info.scope.owner;
3549                 /* if the field isn't static, then we can get the first constructor
3550                  * and use it as the owner of the environment. This is what
3551                  * LTM code is doing to look for type annotations so we are fine.
3552                  */
3553                 if ((owner.flags() & STATIC) == 0) {
3554                     for (Symbol s : enclClass.members_field.getSymbolsByName(names.init)) {
3555                         newScopeOwner = s;
3556                         break;
3557                     }
3558                 } else {
3559                     /* if the field is static then we need to create a fake clinit
3560                      * method, this method can later be reused by LTM.
3561                      */
3562                     MethodSymbol clinit = clinits.get(enclClass);
3563                     if (clinit == null) {
3564                         Type clinitType = new MethodType(List.nil(),
3565                                 syms.voidType, List.nil(), syms.methodClass);
3566                         clinit = new MethodSymbol(STATIC | SYNTHETIC | PRIVATE,
3567                                 names.clinit, clinitType, enclClass);
3568                         clinit.params = List.nil();
3569                         clinits.put(enclClass, clinit);
3570                     }
3571                     newScopeOwner = clinit;
3572                 }
3573                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(newScopeOwner)));
3574             } else {
3575                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3576             }
3577             lambdaEnv.info.yieldResult = null;
3578             lambdaEnv.info.isLambda = true;
3579             return lambdaEnv;
3580         }
3581 
3582     @Override
3583     public void visitReference(final JCMemberReference that) {
3584         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3585             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3586                 //method reference only allowed in assignment or method invocation/cast context
3587                 log.error(that.pos(), Errors.UnexpectedMref);
3588             }
3589             result = that.type = types.createErrorType(pt());
3590             return;
3591         }
3592         final Env<AttrContext> localEnv = env.dup(that);
3593         try {
3594             //attribute member reference qualifier - if this is a constructor
3595             //reference, the expected kind must be a type
3596             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3597 
3598             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3599                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3600                 if (!exprType.isErroneous() &&
3601                     exprType.isRaw() &&
3602                     that.typeargs != null) {
3603                     log.error(that.expr.pos(),
3604                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3605                                                  Fragments.MrefInferAndExplicitParams));
3606                     exprType = types.createErrorType(exprType);
3607                 }
3608             }
3609 
3610             if (exprType.isErroneous()) {
3611                 //if the qualifier expression contains problems,
3612                 //give up attribution of method reference
3613                 result = that.type = exprType;
3614                 return;
3615             }
3616 
3617             if (TreeInfo.isStaticSelector(that.expr, names)) {
3618                 //if the qualifier is a type, validate it; raw warning check is
3619                 //omitted as we don't know at this stage as to whether this is a
3620                 //raw selector (because of inference)
3621                 chk.validate(that.expr, env, false);
3622             } else {
3623                 Symbol lhsSym = TreeInfo.symbol(that.expr);
3624                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
3625             }
3626             //attrib type-arguments
3627             List<Type> typeargtypes = List.nil();
3628             if (that.typeargs != null) {
3629                 typeargtypes = attribTypes(that.typeargs, localEnv);
3630             }
3631 
3632             boolean isTargetSerializable =
3633                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3634                     rs.isSerializable(pt());
3635             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
3636             Type currentTarget = targetInfo.target;
3637             Type desc = targetInfo.descriptor;
3638 
3639             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
3640             List<Type> argtypes = desc.getParameterTypes();
3641             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
3642 
3643             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
3644                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
3645             }
3646 
3647             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
3648             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
3649             try {
3650                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
3651                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
3652                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
3653             } finally {
3654                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
3655             }
3656 
3657             Symbol refSym = refResult.fst;
3658             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
3659 
3660             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
3661              *  JDK-8075541
3662              */
3663             if (refSym.kind != MTH) {
3664                 boolean targetError;
3665                 switch (refSym.kind) {
3666                     case ABSENT_MTH:
3667                     case MISSING_ENCL:
3668                         targetError = false;
3669                         break;
3670                     case WRONG_MTH:
3671                     case WRONG_MTHS:
3672                     case AMBIGUOUS:
3673                     case HIDDEN:
3674                     case STATICERR:
3675                         targetError = true;
3676                         break;
3677                     default:
3678                         Assert.error("unexpected result kind " + refSym.kind);
3679                         targetError = false;
3680                 }
3681 
3682                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
3683                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
3684                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
3685 
3686                 JCDiagnostic diag = diags.create(log.currentSource(), that,
3687                         targetError ?
3688                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
3689                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
3690 
3691                 if (targetError && currentTarget == Type.recoveryType) {
3692                     //a target error doesn't make sense during recovery stage
3693                     //as we don't know what actual parameter types are
3694                     result = that.type = currentTarget;
3695                     return;
3696                 } else {
3697                     if (targetError) {
3698                         resultInfo.checkContext.report(that, diag);
3699                     } else {
3700                         log.report(diag);
3701                     }
3702                     result = that.type = types.createErrorType(currentTarget);
3703                     return;
3704                 }
3705             }
3706 
3707             that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
3708             that.kind = lookupHelper.referenceKind(that.sym);
3709             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
3710 
3711             if (desc.getReturnType() == Type.recoveryType) {
3712                 // stop here
3713                 result = that.type = currentTarget;
3714                 return;
3715             }
3716 
3717             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3718                 Type enclosingType = exprType.getEnclosingType();
3719                 if (enclosingType != null && enclosingType.hasTag(CLASS)) {
3720                     // Check for the existence of an appropriate outer instance
3721                     rs.resolveImplicitThis(that.pos(), env, exprType);
3722                 }
3723             }
3724 
3725             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3726 
3727                 if (that.getMode() == ReferenceMode.INVOKE &&
3728                         TreeInfo.isStaticSelector(that.expr, names) &&
3729                         that.kind.isUnbound() &&
3730                         lookupHelper.site.isRaw()) {
3731                     chk.checkRaw(that.expr, localEnv);
3732                 }
3733 
3734                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
3735                         exprType.getTypeArguments().nonEmpty()) {
3736                     //static ref with class type-args
3737                     log.error(that.expr.pos(),
3738                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3739                                                  Fragments.StaticMrefWithTargs));
3740                     result = that.type = types.createErrorType(currentTarget);
3741                     return;
3742                 }
3743 
3744                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
3745                     // Check that super-qualified symbols are not abstract (JLS)
3746                     rs.checkNonAbstract(that.pos(), that.sym);
3747                 }
3748 
3749                 if (isTargetSerializable) {
3750                     chk.checkAccessFromSerializableElement(that, true);
3751                 }
3752             }
3753 
3754             ResultInfo checkInfo =
3755                     resultInfo.dup(newMethodTemplate(
3756                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
3757                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
3758                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3759 
3760             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
3761 
3762             if (that.kind.isUnbound() &&
3763                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
3764                 //re-generate inference constraints for unbound receiver
3765                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
3766                     //cannot happen as this has already been checked - we just need
3767                     //to regenerate the inference constraints, as that has been lost
3768                     //as a result of the call to inferenceContext.save()
3769                     Assert.error("Can't get here");
3770                 }
3771             }
3772 
3773             if (!refType.isErroneous()) {
3774                 refType = types.createMethodTypeWithReturn(refType,
3775                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
3776             }
3777 
3778             //go ahead with standard method reference compatibility check - note that param check
3779             //is a no-op (as this has been taken care during method applicability)
3780             boolean isSpeculativeRound =
3781                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3782 
3783             that.type = currentTarget; //avoids recovery at this stage
3784             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
3785             if (!isSpeculativeRound) {
3786                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
3787             }
3788             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3789         } catch (Types.FunctionDescriptorLookupError ex) {
3790             JCDiagnostic cause = ex.getDiagnostic();
3791             resultInfo.checkContext.report(that, cause);
3792             result = that.type = types.createErrorType(pt());
3793             return;
3794         }
3795     }
3796     //where
3797         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
3798             //if this is a constructor reference, the expected kind must be a type
3799             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
3800                                   KindSelector.VAL_TYP : KindSelector.TYP,
3801                                   Type.noType);
3802         }
3803 
3804 
3805     @SuppressWarnings("fallthrough")
3806     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
3807         InferenceContext inferenceContext = checkContext.inferenceContext();
3808         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
3809 
3810         Type resType;
3811         switch (tree.getMode()) {
3812             case NEW:
3813                 if (!tree.expr.type.isRaw()) {
3814                     resType = tree.expr.type;
3815                     break;
3816                 }
3817             default:
3818                 resType = refType.getReturnType();
3819         }
3820 
3821         Type incompatibleReturnType = resType;
3822 
3823         if (returnType.hasTag(VOID)) {
3824             incompatibleReturnType = null;
3825         }
3826 
3827         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
3828             if (resType.isErroneous() ||
3829                     new FunctionalReturnContext(checkContext).compatible(resType, returnType,
3830                             checkContext.checkWarner(tree, resType, returnType))) {
3831                 incompatibleReturnType = null;
3832             }
3833         }
3834 
3835         if (incompatibleReturnType != null) {
3836             Fragment msg =
3837                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
3838             checkContext.report(tree, diags.fragment(msg));
3839         } else {
3840             if (inferenceContext.free(refType)) {
3841                 // we need to wait for inference to finish and then replace inference vars in the referent type
3842                 inferenceContext.addFreeTypeListener(List.of(refType),
3843                         instantiatedContext -> {
3844                             tree.referentType = instantiatedContext.asInstType(refType);
3845                         });
3846             } else {
3847                 tree.referentType = refType;
3848             }
3849         }
3850 
3851         if (!speculativeAttr) {
3852             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
3853                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
3854             }
3855         }
3856     }
3857 
3858     boolean checkExConstraints(
3859             List<Type> thrownByFuncExpr,
3860             List<Type> thrownAtFuncType,
3861             InferenceContext inferenceContext) {
3862         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
3863          *  are not proper types
3864          */
3865         List<Type> nonProperList = thrownAtFuncType.stream()
3866                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
3867         List<Type> properList = thrownAtFuncType.diff(nonProperList);
3868 
3869         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
3870          *  in the throws clause of the invocation type of the method reference's compile-time
3871          *  declaration
3872          */
3873         List<Type> checkedList = thrownByFuncExpr.stream()
3874                 .filter(e -> chk.isChecked(e)).collect(List.collector());
3875 
3876         /** If n = 0 (the function type's throws clause consists only of proper types), then
3877          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
3878          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
3879          *  reduces to true
3880          */
3881         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
3882         for (Type checked : checkedList) {
3883             boolean isSubtype = false;
3884             for (Type proper : properList) {
3885                 if (types.isSubtype(checked, proper)) {
3886                     isSubtype = true;
3887                     break;
3888                 }
3889             }
3890             if (!isSubtype) {
3891                 uncaughtByProperTypes.add(checked);
3892             }
3893         }
3894 
3895         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
3896             return false;
3897         }
3898 
3899         /** If n > 0, the constraint reduces to a set of subtyping constraints:
3900          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
3901          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
3902          */
3903         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
3904         uncaughtByProperTypes.forEach(checkedEx -> {
3905             nonProperAsUndet.forEach(nonProper -> {
3906                 types.isSubtype(checkedEx, nonProper);
3907             });
3908         });
3909 
3910         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
3911          */
3912         nonProperAsUndet.stream()
3913                 .filter(t -> t.hasTag(UNDETVAR))
3914                 .forEach(t -> ((UndetVar)t).setThrow());
3915         return true;
3916     }
3917 
3918     /**
3919      * Set functional type info on the underlying AST. Note: as the target descriptor
3920      * might contain inference variables, we might need to register an hook in the
3921      * current inference context.
3922      */
3923     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
3924             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
3925         if (checkContext.inferenceContext().free(descriptorType)) {
3926             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
3927                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
3928                     inferenceContext.asInstType(primaryTarget), checkContext));
3929         } else {
3930             if (pt.hasTag(CLASS)) {
3931                 fExpr.target = primaryTarget;
3932             }
3933             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3934                     pt != Type.recoveryType) {
3935                 //check that functional interface class is well-formed
3936                 try {
3937                     /* Types.makeFunctionalInterfaceClass() may throw an exception
3938                      * when it's executed post-inference. See the listener code
3939                      * above.
3940                      */
3941                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
3942                             names.empty, fExpr.target, ABSTRACT);
3943                     if (csym != null) {
3944                         chk.checkImplementations(env.tree, csym, csym);
3945                         try {
3946                             //perform an additional functional interface check on the synthetic class,
3947                             //as there may be spurious errors for raw targets - because of existing issues
3948                             //with membership and inheritance (see JDK-8074570).
3949                             csym.flags_field |= INTERFACE;
3950                             types.findDescriptorType(csym.type);
3951                         } catch (FunctionDescriptorLookupError err) {
3952                             resultInfo.checkContext.report(fExpr,
3953                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
3954                         }
3955                     }
3956                 } catch (Types.FunctionDescriptorLookupError ex) {
3957                     JCDiagnostic cause = ex.getDiagnostic();
3958                     resultInfo.checkContext.report(env.tree, cause);
3959                 }
3960             }
3961         }
3962     }
3963 
3964     public void visitParens(JCParens tree) {
3965         Type owntype = attribTree(tree.expr, env, resultInfo);
3966         result = check(tree, owntype, pkind(), resultInfo);
3967         Symbol sym = TreeInfo.symbol(tree);
3968         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
3969             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
3970     }
3971 
3972     public void visitAssign(JCAssign tree) {
3973         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
3974         Type capturedType = capture(owntype);
3975         attribExpr(tree.rhs, env, owntype);
3976         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
3977     }
3978 
3979     public void visitAssignop(JCAssignOp tree) {
3980         // Attribute arguments.
3981         Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
3982         Type operand = attribExpr(tree.rhs, env);
3983         // Find operator.
3984         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
3985         if (operator != operators.noOpSymbol &&
3986                 !owntype.isErroneous() &&
3987                 !operand.isErroneous()) {
3988             chk.checkDivZero(tree.rhs.pos(), operator, operand);
3989             chk.checkCastable(tree.rhs.pos(),
3990                               operator.type.getReturnType(),
3991                               owntype);
3992             chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
3993         }
3994         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3995     }
3996 
3997     public void visitUnary(JCUnary tree) {
3998         // Attribute arguments.
3999         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
4000             ? attribTree(tree.arg, env, varAssignmentInfo)
4001             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
4002 
4003         // Find operator.
4004         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
4005         Type owntype = types.createErrorType(tree.type);
4006         if (operator != operators.noOpSymbol &&
4007                 !argtype.isErroneous()) {
4008             owntype = (tree.getTag().isIncOrDecUnaryOp())
4009                 ? tree.arg.type
4010                 : operator.type.getReturnType();
4011             int opc = operator.opcode;
4012 
4013             // If the argument is constant, fold it.
4014             if (argtype.constValue() != null) {
4015                 Type ctype = cfolder.fold1(opc, argtype);
4016                 if (ctype != null) {
4017                     owntype = cfolder.coerce(ctype, owntype);
4018                 }
4019             }
4020         }
4021         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4022         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4023     }
4024 
4025     public void visitBinary(JCBinary tree) {
4026         // Attribute arguments.
4027         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4028         // x && y
4029         // include x's bindings when true in y
4030 
4031         // x || y
4032         // include x's bindings when false in y
4033 
4034         MatchBindings lhsBindings = matchBindings;
4035         List<BindingSymbol> propagatedBindings;
4036         switch (tree.getTag()) {
4037             case AND:
4038                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4039                 break;
4040             case OR:
4041                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4042                 break;
4043             default:
4044                 propagatedBindings = List.nil();
4045                 break;
4046         }
4047         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4048         Type right;
4049         try {
4050             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4051         } finally {
4052             rhsEnv.info.scope.leave();
4053         }
4054 
4055         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4056 
4057         // Find operator.
4058         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4059         Type owntype = types.createErrorType(tree.type);
4060         if (operator != operators.noOpSymbol &&
4061                 !left.isErroneous() &&
4062                 !right.isErroneous()) {
4063             owntype = operator.type.getReturnType();
4064             int opc = operator.opcode;
4065             // If both arguments are constants, fold them.
4066             if (left.constValue() != null && right.constValue() != null) {
4067                 Type ctype = cfolder.fold2(opc, left, right);
4068                 if (ctype != null) {
4069                     owntype = cfolder.coerce(ctype, owntype);
4070                 }
4071             }
4072 
4073             // Check that argument types of a reference ==, != are
4074             // castable to each other, (JLS 15.21).  Note: unboxing
4075             // comparisons will not have an acmp* opc at this point.
4076             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4077                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4078                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4079                 }
4080             }
4081 
4082             chk.checkDivZero(tree.rhs.pos(), operator, right);
4083         }
4084         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4085     }
4086 
4087     public void visitTypeCast(final JCTypeCast tree) {
4088         Type clazztype = attribType(tree.clazz, env);
4089         chk.validate(tree.clazz, env, false);
4090         //a fresh environment is required for 292 inference to work properly ---
4091         //see Infer.instantiatePolymorphicSignatureInstance()
4092         Env<AttrContext> localEnv = env.dup(tree);
4093         //should we propagate the target type?
4094         final ResultInfo castInfo;
4095         JCExpression expr = TreeInfo.skipParens(tree.expr);
4096         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4097         if (isPoly) {
4098             //expression is a poly - we need to propagate target type info
4099             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4100                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4101                 @Override
4102                 public boolean compatible(Type found, Type req, Warner warn) {
4103                     return types.isCastable(found, req, warn);
4104                 }
4105             });
4106         } else {
4107             //standalone cast - target-type info is not propagated
4108             castInfo = unknownExprInfo;
4109         }
4110         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4111         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4112         if (exprtype.constValue() != null)
4113             owntype = cfolder.coerce(exprtype, owntype);
4114         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4115         if (!isPoly)
4116             chk.checkRedundantCast(localEnv, tree);
4117     }
4118 
4119     public void visitTypeTest(JCInstanceOf tree) {
4120         Type exprtype = chk.checkNullOrRefType(
4121                 tree.expr.pos(), attribExpr(tree.expr, env));
4122         Type clazztype;
4123         JCTree typeTree;
4124         if (tree.pattern.getTag() == BINDINGPATTERN ||
4125             tree.pattern.getTag() == RECORDPATTERN) {
4126             attribExpr(tree.pattern, env, exprtype);
4127             clazztype = tree.pattern.type;
4128             if (types.isSubtype(exprtype, clazztype) &&
4129                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4130                 tree.pattern.getTag() != RECORDPATTERN) {
4131                 if (!allowUnconditionalPatternsInstanceOf) {
4132                     log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(),
4133                               Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.error(this.sourceName));
4134                 }
4135             }
4136             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4137         } else {
4138             clazztype = attribType(tree.pattern, env);
4139             typeTree = tree.pattern;
4140             chk.validate(typeTree, env, false);
4141         }
4142         if (!clazztype.hasTag(TYPEVAR)) {
4143             clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4144         }
4145         if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4146             boolean valid = false;
4147             if (allowReifiableTypesInInstanceof) {
4148                 valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4149             } else {
4150                 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(),
4151                           Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4152                 allowReifiableTypesInInstanceof = true;
4153             }
4154             if (!valid) {
4155                 clazztype = types.createErrorType(clazztype);
4156             }
4157         }
4158         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4159         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4160     }
4161 
4162     private boolean checkCastablePattern(DiagnosticPosition pos,
4163                                          Type exprType,
4164                                          Type pattType) {
4165         Warner warner = new Warner();
4166         // if any type is erroneous, the problem is reported elsewhere
4167         if (exprType.isErroneous() || pattType.isErroneous()) {
4168             return false;
4169         }
4170         if (!types.isCastable(exprType, pattType, warner)) {
4171             chk.basicHandler.report(pos,
4172                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4173             return false;
4174         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4175                    (!exprType.isPrimitive() ||
4176                     !pattType.isPrimitive() ||
4177                     !types.isSameType(exprType, pattType))) {
4178             chk.basicHandler.report(pos,
4179                     diags.fragment(Fragments.NotApplicableTypes(exprType, pattType)));
4180             return false;
4181         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4182             log.error(pos,
4183                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4184             return false;
4185         } else {
4186             return true;
4187         }
4188     }
4189 
4190     @Override
4191     public void visitAnyPattern(JCAnyPattern tree) {
4192         result = tree.type = resultInfo.pt;
4193     }
4194 
4195     public void visitBindingPattern(JCBindingPattern tree) {
4196         Type type;
4197         if (tree.var.vartype != null) {
4198             type = attribType(tree.var.vartype, env);
4199         } else {
4200             type = resultInfo.pt;
4201         }
4202         tree.type = tree.var.type = type;
4203         BindingSymbol v = new BindingSymbol(tree.var.mods.flags, tree.var.name, type, env.info.scope.owner);
4204         v.pos = tree.pos;
4205         tree.var.sym = v;
4206         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4207             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4208         }
4209         annotate.annotateLater(tree.var.mods.annotations, env, v, tree.pos());
4210         if (!tree.var.isImplicitlyTyped()) {
4211             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v, tree.var.pos());
4212         }
4213         annotate.flush();
4214         chk.validate(tree.var.vartype, env, true);
4215         result = tree.type;
4216         if (v.isUnnamedVariable()) {
4217             matchBindings = MatchBindingsComputer.EMPTY;
4218         } else {
4219             matchBindings = new MatchBindings(List.of(v), List.nil());
4220         }
4221     }
4222 
4223     @Override
4224     public void visitRecordPattern(JCRecordPattern tree) {
4225         Type site;
4226 
4227         if (tree.deconstructor == null) {
4228             log.error(tree.pos(), Errors.DeconstructionPatternVarNotAllowed);
4229             tree.record = syms.errSymbol;
4230             site = tree.type = types.createErrorType(tree.record.type);
4231         } else {
4232             Type type = attribType(tree.deconstructor, env);
4233             if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4234                 Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4235                 if (inferred == null) {
4236                     log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4237                 } else {
4238                     type = inferred;
4239                 }
4240             }
4241             tree.type = tree.deconstructor.type = type;
4242             site = types.capture(tree.type);
4243         }
4244 
4245         List<Type> expectedRecordTypes;
4246         if (site.tsym.kind == Kind.TYP && ((ClassSymbol) site.tsym).isRecord()) {
4247             ClassSymbol record = (ClassSymbol) site.tsym;
4248             expectedRecordTypes = record.getRecordComponents()
4249                                         .stream()
4250                                         .map(rc -> types.memberType(site, rc))
4251                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4252                                         .collect(List.collector());
4253             tree.record = record;
4254         } else {
4255             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4256             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4257                                 .limit(tree.nested.size())
4258                                 .collect(List.collector());
4259             tree.record = syms.errSymbol;
4260         }
4261         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4262         List<Type> recordTypes = expectedRecordTypes;
4263         List<JCPattern> nestedPatterns = tree.nested;
4264         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4265         try {
4266             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4267                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4268                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4269                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4270                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4271                 nestedPatterns = nestedPatterns.tail;
4272                 recordTypes = recordTypes.tail;
4273             }
4274             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4275                 while (nestedPatterns.nonEmpty()) {
4276                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4277                     nestedPatterns = nestedPatterns.tail;
4278                 }
4279                 List<Type> nestedTypes =
4280                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4281                 log.error(tree.pos(),
4282                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4283                                                                  nestedTypes));
4284             }
4285         } finally {
4286             localEnv.info.scope.leave();
4287         }
4288         chk.validate(tree.deconstructor, env, true);
4289         result = tree.type;
4290         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4291     }
4292 
4293     public void visitIndexed(JCArrayAccess tree) {
4294         Type owntype = types.createErrorType(tree.type);
4295         Type atype = attribExpr(tree.indexed, env);
4296         attribExpr(tree.index, env, syms.intType);
4297         if (types.isArray(atype))
4298             owntype = types.elemtype(atype);
4299         else if (!atype.hasTag(ERROR))
4300             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4301         if (!pkind().contains(KindSelector.VAL))
4302             owntype = capture(owntype);
4303         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4304     }
4305 
4306     public void visitIdent(JCIdent tree) {
4307         Symbol sym;
4308 
4309         // Find symbol
4310         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4311             // If we are looking for a method, the prototype `pt' will be a
4312             // method type with the type of the call's arguments as parameters.
4313             env.info.pendingResolutionPhase = null;
4314             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4315         } else if (tree.sym != null && tree.sym.kind != VAR) {
4316             sym = tree.sym;
4317         } else {
4318             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4319         }
4320         tree.sym = sym;
4321 
4322         // Also find the environment current for the class where
4323         // sym is defined (`symEnv').
4324         Env<AttrContext> symEnv = env;
4325         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4326             sym.kind.matches(KindSelector.VAL_MTH) &&
4327             sym.owner.kind == TYP &&
4328             tree.name != names._this && tree.name != names._super) {
4329 
4330             // Find environment in which identifier is defined.
4331             while (symEnv.outer != null &&
4332                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4333                 symEnv = symEnv.outer;
4334             }
4335         }
4336 
4337         // If symbol is a variable, ...
4338         if (sym.kind == VAR) {
4339             VarSymbol v = (VarSymbol)sym;
4340 
4341             // ..., evaluate its initializer, if it has one, and check for
4342             // illegal forward reference.
4343             checkInit(tree, env, v, false);
4344 
4345             // If we are expecting a variable (as opposed to a value), check
4346             // that the variable is assignable in the current environment.
4347             if (KindSelector.ASG.subset(pkind()))
4348                 checkAssignable(tree.pos(), v, null, env);
4349         }
4350 
4351         Env<AttrContext> env1 = env;
4352         if (sym.kind != ERR && sym.kind != TYP &&
4353             sym.owner != null && sym.owner != env1.enclClass.sym) {
4354             // If the found symbol is inaccessible, then it is
4355             // accessed through an enclosing instance.  Locate this
4356             // enclosing instance:
4357             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4358                 env1 = env1.outer;
4359         }
4360 
4361         if (env.info.isSerializable) {
4362             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4363         }
4364 
4365         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4366     }
4367 
4368     public void visitSelect(JCFieldAccess tree) {
4369         // Determine the expected kind of the qualifier expression.
4370         KindSelector skind = KindSelector.NIL;
4371         if (tree.name == names._this || tree.name == names._super ||
4372                 tree.name == names._class)
4373         {
4374             skind = KindSelector.TYP;
4375         } else {
4376             if (pkind().contains(KindSelector.PCK))
4377                 skind = KindSelector.of(skind, KindSelector.PCK);
4378             if (pkind().contains(KindSelector.TYP))
4379                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4380             if (pkind().contains(KindSelector.VAL_MTH))
4381                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4382         }
4383 
4384         // Attribute the qualifier expression, and determine its symbol (if any).
4385         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
4386         Assert.check(site == tree.selected.type);
4387         if (!pkind().contains(KindSelector.TYP_PCK))
4388             site = capture(site); // Capture field access
4389 
4390         // don't allow T.class T[].class, etc
4391         if (skind == KindSelector.TYP) {
4392             Type elt = site;
4393             while (elt.hasTag(ARRAY))
4394                 elt = ((ArrayType)elt).elemtype;
4395             if (elt.hasTag(TYPEVAR)) {
4396                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4397                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4398                 tree.sym = tree.type.tsym;
4399                 return ;
4400             }
4401         }
4402 
4403         // If qualifier symbol is a type or `super', assert `selectSuper'
4404         // for the selection. This is relevant for determining whether
4405         // protected symbols are accessible.
4406         Symbol sitesym = TreeInfo.symbol(tree.selected);
4407         boolean selectSuperPrev = env.info.selectSuper;
4408         env.info.selectSuper =
4409             sitesym != null &&
4410             sitesym.name == names._super;
4411 
4412         // Determine the symbol represented by the selection.
4413         env.info.pendingResolutionPhase = null;
4414         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
4415         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4416             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4417             sym = syms.errSymbol;
4418         }
4419         if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
4420             site = capture(site);
4421             sym = selectSym(tree, sitesym, site, env, resultInfo);
4422         }
4423         boolean varArgs = env.info.lastResolveVarargs();
4424         tree.sym = sym;
4425 
4426         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4427             site = types.skipTypeVars(site, true);
4428         }
4429 
4430         // If that symbol is a variable, ...
4431         if (sym.kind == VAR) {
4432             VarSymbol v = (VarSymbol)sym;
4433 
4434             // ..., evaluate its initializer, if it has one, and check for
4435             // illegal forward reference.
4436             checkInit(tree, env, v, true);
4437 
4438             // If we are expecting a variable (as opposed to a value), check
4439             // that the variable is assignable in the current environment.
4440             if (KindSelector.ASG.subset(pkind()))
4441                 checkAssignable(tree.pos(), v, tree.selected, env);
4442         }
4443 
4444         if (sitesym != null &&
4445                 sitesym.kind == VAR &&
4446                 ((VarSymbol)sitesym).isResourceVariable() &&
4447                 sym.kind == MTH &&
4448                 sym.name.equals(names.close) &&
4449                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
4450                 env.info.lint.isEnabled(LintCategory.TRY)) {
4451             log.warning(LintCategory.TRY, tree, Warnings.TryExplicitCloseCall);
4452         }
4453 
4454         // Disallow selecting a type from an expression
4455         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4456             tree.type = check(tree.selected, pt(),
4457                               sitesym == null ?
4458                                       KindSelector.VAL : sitesym.kind.toSelector(),
4459                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4460         }
4461 
4462         if (isType(sitesym)) {
4463             if (sym.name != names._this && sym.name != names._super) {
4464                 // Check if type-qualified fields or methods are static (JLS)
4465                 if ((sym.flags() & STATIC) == 0 &&
4466                     sym.name != names._super &&
4467                     (sym.kind == VAR || sym.kind == MTH)) {
4468                     rs.accessBase(rs.new StaticError(sym),
4469                               tree.pos(), site, sym.name, true);
4470                 }
4471             }
4472         } else if (sym.kind != ERR &&
4473                    (sym.flags() & STATIC) != 0 &&
4474                    sym.name != names._class) {
4475             // If the qualified item is not a type and the selected item is static, report
4476             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4477             if (!sym.owner.isAnonymous()) {
4478                 chk.warnStatic(tree, Warnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4479             } else {
4480                 chk.warnStatic(tree, Warnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4481             }
4482         }
4483 
4484         // If we are selecting an instance member via a `super', ...
4485         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4486 
4487             // Check that super-qualified symbols are not abstract (JLS)
4488             rs.checkNonAbstract(tree.pos(), sym);
4489 
4490             if (site.isRaw()) {
4491                 // Determine argument types for site.
4492                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
4493                 if (site1 != null) site = site1;
4494             }
4495         }
4496 
4497         if (env.info.isSerializable) {
4498             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4499         }
4500 
4501         env.info.selectSuper = selectSuperPrev;
4502         result = checkId(tree, site, sym, env, resultInfo);
4503     }
4504     //where
4505         /** Determine symbol referenced by a Select expression,
4506          *
4507          *  @param tree   The select tree.
4508          *  @param site   The type of the selected expression,
4509          *  @param env    The current environment.
4510          *  @param resultInfo The current result.
4511          */
4512         private Symbol selectSym(JCFieldAccess tree,
4513                                  Symbol location,
4514                                  Type site,
4515                                  Env<AttrContext> env,
4516                                  ResultInfo resultInfo) {
4517             DiagnosticPosition pos = tree.pos();
4518             Name name = tree.name;
4519             switch (site.getTag()) {
4520             case PACKAGE:
4521                 return rs.accessBase(
4522                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4523                     pos, location, site, name, true);
4524             case ARRAY:
4525             case CLASS:
4526                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4527                     return rs.resolveQualifiedMethod(
4528                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4529                 } else if (name == names._this || name == names._super) {
4530                     return rs.resolveSelf(pos, env, site.tsym, name);
4531                 } else if (name == names._class) {
4532                     // In this case, we have already made sure in
4533                     // visitSelect that qualifier expression is a type.
4534                     return syms.getClassField(site, types);
4535                 } else {
4536                     // We are seeing a plain identifier as selector.
4537                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
4538                         sym = rs.accessBase(sym, pos, location, site, name, true);
4539                     return sym;
4540                 }
4541             case WILDCARD:
4542                 throw new AssertionError(tree);
4543             case TYPEVAR:
4544                 // Normally, site.getUpperBound() shouldn't be null.
4545                 // It should only happen during memberEnter/attribBase
4546                 // when determining the supertype which *must* be
4547                 // done before attributing the type variables.  In
4548                 // other words, we are seeing this illegal program:
4549                 // class B<T> extends A<T.foo> {}
4550                 Symbol sym = (site.getUpperBound() != null)
4551                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
4552                     : null;
4553                 if (sym == null) {
4554                     log.error(pos, Errors.TypeVarCantBeDeref);
4555                     return syms.errSymbol;
4556                 } else {
4557                     Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
4558                         rs.new AccessError(env, site, sym) :
4559                                 sym;
4560                     rs.accessBase(sym2, pos, location, site, name, true);
4561                     return sym;
4562                 }
4563             case ERROR:
4564                 // preserve identifier names through errors
4565                 return types.createErrorType(name, site.tsym, site).tsym;
4566             default:
4567                 // The qualifier expression is of a primitive type -- only
4568                 // .class is allowed for these.
4569                 if (name == names._class) {
4570                     // In this case, we have already made sure in Select that
4571                     // qualifier expression is a type.
4572                     return syms.getClassField(site, types);
4573                 } else {
4574                     log.error(pos, Errors.CantDeref(site));
4575                     return syms.errSymbol;
4576                 }
4577             }
4578         }
4579 
4580         /** Determine type of identifier or select expression and check that
4581          *  (1) the referenced symbol is not deprecated
4582          *  (2) the symbol's type is safe (@see checkSafe)
4583          *  (3) if symbol is a variable, check that its type and kind are
4584          *      compatible with the prototype and protokind.
4585          *  (4) if symbol is an instance field of a raw type,
4586          *      which is being assigned to, issue an unchecked warning if its
4587          *      type changes under erasure.
4588          *  (5) if symbol is an instance method of a raw type, issue an
4589          *      unchecked warning if its argument types change under erasure.
4590          *  If checks succeed:
4591          *    If symbol is a constant, return its constant type
4592          *    else if symbol is a method, return its result type
4593          *    otherwise return its type.
4594          *  Otherwise return errType.
4595          *
4596          *  @param tree       The syntax tree representing the identifier
4597          *  @param site       If this is a select, the type of the selected
4598          *                    expression, otherwise the type of the current class.
4599          *  @param sym        The symbol representing the identifier.
4600          *  @param env        The current environment.
4601          *  @param resultInfo    The expected result
4602          */
4603         Type checkId(JCTree tree,
4604                      Type site,
4605                      Symbol sym,
4606                      Env<AttrContext> env,
4607                      ResultInfo resultInfo) {
4608             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
4609                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
4610                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4611         }
4612 
4613         Type checkMethodIdInternal(JCTree tree,
4614                      Type site,
4615                      Symbol sym,
4616                      Env<AttrContext> env,
4617                      ResultInfo resultInfo) {
4618             if (resultInfo.pkind.contains(KindSelector.POLY)) {
4619                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
4620             } else {
4621                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4622             }
4623         }
4624 
4625         Type checkIdInternal(JCTree tree,
4626                      Type site,
4627                      Symbol sym,
4628                      Type pt,
4629                      Env<AttrContext> env,
4630                      ResultInfo resultInfo) {
4631             if (pt.isErroneous()) {
4632                 return types.createErrorType(site);
4633             }
4634             Type owntype; // The computed type of this identifier occurrence.
4635             switch (sym.kind) {
4636             case TYP:
4637                 // For types, the computed type equals the symbol's type,
4638                 // except for two situations:
4639                 owntype = sym.type;
4640                 if (owntype.hasTag(CLASS)) {
4641                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
4642                     Type ownOuter = owntype.getEnclosingType();
4643 
4644                     // (a) If the symbol's type is parameterized, erase it
4645                     // because no type parameters were given.
4646                     // We recover generic outer type later in visitTypeApply.
4647                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
4648                         owntype = types.erasure(owntype);
4649                     }
4650 
4651                     // (b) If the symbol's type is an inner class, then
4652                     // we have to interpret its outer type as a superclass
4653                     // of the site type. Example:
4654                     //
4655                     // class Tree<A> { class Visitor { ... } }
4656                     // class PointTree extends Tree<Point> { ... }
4657                     // ...PointTree.Visitor...
4658                     //
4659                     // Then the type of the last expression above is
4660                     // Tree<Point>.Visitor.
4661                     else if (ownOuter.hasTag(CLASS) && site != ownOuter) {
4662                         Type normOuter = site;
4663                         if (normOuter.hasTag(CLASS)) {
4664                             normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
4665                         }
4666                         if (normOuter == null) // perhaps from an import
4667                             normOuter = types.erasure(ownOuter);
4668                         if (normOuter != ownOuter)
4669                             owntype = new ClassType(
4670                                 normOuter, List.nil(), owntype.tsym,
4671                                 owntype.getMetadata());
4672                     }
4673                 }
4674                 break;
4675             case VAR:
4676                 VarSymbol v = (VarSymbol)sym;
4677 
4678                 if (env.info.enclVar != null
4679                         && v.type.hasTag(NONE)) {
4680                     //self reference to implicitly typed variable declaration
4681                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
4682                     return tree.type = v.type = types.createErrorType(v.type);
4683                 }
4684 
4685                 // Test (4): if symbol is an instance field of a raw type,
4686                 // which is being assigned to, issue an unchecked warning if
4687                 // its type changes under erasure.
4688                 if (KindSelector.ASG.subset(pkind()) &&
4689                     v.owner.kind == TYP &&
4690                     (v.flags() & STATIC) == 0 &&
4691                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4692                     Type s = types.asOuterSuper(site, v.owner);
4693                     if (s != null &&
4694                         s.isRaw() &&
4695                         !types.isSameType(v.type, v.erasure(types))) {
4696                         chk.warnUnchecked(tree.pos(), Warnings.UncheckedAssignToVar(v, s));
4697                     }
4698                 }
4699                 // The computed type of a variable is the type of the
4700                 // variable symbol, taken as a member of the site type.
4701                 owntype = (sym.owner.kind == TYP &&
4702                            sym.name != names._this && sym.name != names._super)
4703                     ? types.memberType(site, sym)
4704                     : sym.type;
4705 
4706                 // If the variable is a constant, record constant value in
4707                 // computed type.
4708                 if (v.getConstValue() != null && isStaticReference(tree))
4709                     owntype = owntype.constType(v.getConstValue());
4710 
4711                 if (resultInfo.pkind == KindSelector.VAL) {
4712                     owntype = capture(owntype); // capture "names as expressions"
4713                 }
4714                 break;
4715             case MTH: {
4716                 owntype = checkMethod(site, sym,
4717                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
4718                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
4719                         resultInfo.pt.getTypeArguments());
4720                 chk.checkRestricted(tree.pos(), sym);
4721                 break;
4722             }
4723             case PCK: case ERR:
4724                 owntype = sym.type;
4725                 break;
4726             default:
4727                 throw new AssertionError("unexpected kind: " + sym.kind +
4728                                          " in tree " + tree);
4729             }
4730 
4731             // Emit a `deprecation' warning if symbol is deprecated.
4732             // (for constructors (but not for constructor references), the error
4733             // was given when the constructor was resolved)
4734 
4735             if (sym.name != names.init || tree.hasTag(REFERENCE)) {
4736                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
4737                 chk.checkSunAPI(tree.pos(), sym);
4738                 chk.checkProfile(tree.pos(), sym);
4739                 chk.checkPreview(tree.pos(), env.info.scope.owner, sym);
4740             }
4741 
4742             // If symbol is a variable, check that its type and
4743             // kind are compatible with the prototype and protokind.
4744             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
4745         }
4746 
4747         /** Check that variable is initialized and evaluate the variable's
4748          *  initializer, if not yet done. Also check that variable is not
4749          *  referenced before it is defined.
4750          *  @param tree    The tree making up the variable reference.
4751          *  @param env     The current environment.
4752          *  @param v       The variable's symbol.
4753          */
4754         private void checkInit(JCTree tree,
4755                                Env<AttrContext> env,
4756                                VarSymbol v,
4757                                boolean onlyWarning) {
4758             // A forward reference is diagnosed if the declaration position
4759             // of the variable is greater than the current tree position
4760             // and the tree and variable definition occur in the same class
4761             // definition.  Note that writes don't count as references.
4762             // This check applies only to class and instance
4763             // variables.  Local variables follow different scope rules,
4764             // and are subject to definite assignment checking.
4765             Env<AttrContext> initEnv = enclosingInitEnv(env);
4766             if (initEnv != null &&
4767                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
4768                 v.owner.kind == TYP &&
4769                 v.owner == env.info.scope.owner.enclClass() &&
4770                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
4771                 (!env.tree.hasTag(ASSIGN) ||
4772                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
4773                 if (!onlyWarning || isStaticEnumField(v)) {
4774                     Error errkey = (initEnv.info.enclVar == v) ?
4775                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
4776                     log.error(tree.pos(), errkey);
4777                 } else if (useBeforeDeclarationWarning) {
4778                     Warning warnkey = (initEnv.info.enclVar == v) ?
4779                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
4780                     log.warning(tree.pos(), warnkey);
4781                 }
4782             }
4783 
4784             v.getConstValue(); // ensure initializer is evaluated
4785 
4786             checkEnumInitializer(tree, env, v);
4787         }
4788 
4789         /**
4790          * Returns the enclosing init environment associated with this env (if any). An init env
4791          * can be either a field declaration env or a static/instance initializer env.
4792          */
4793         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
4794             while (true) {
4795                 switch (env.tree.getTag()) {
4796                     case VARDEF:
4797                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
4798                         if (vdecl.sym.owner.kind == TYP) {
4799                             //field
4800                             return env;
4801                         }
4802                         break;
4803                     case BLOCK:
4804                         if (env.next.tree.hasTag(CLASSDEF)) {
4805                             //instance/static initializer
4806                             return env;
4807                         }
4808                         break;
4809                     case METHODDEF:
4810                     case CLASSDEF:
4811                     case TOPLEVEL:
4812                         return null;
4813                 }
4814                 Assert.checkNonNull(env.next);
4815                 env = env.next;
4816             }
4817         }
4818 
4819         /**
4820          * Check for illegal references to static members of enum.  In
4821          * an enum type, constructors and initializers may not
4822          * reference its static members unless they are constant.
4823          *
4824          * @param tree    The tree making up the variable reference.
4825          * @param env     The current environment.
4826          * @param v       The variable's symbol.
4827          * @jls 8.9 Enum Types
4828          */
4829         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
4830             // JLS:
4831             //
4832             // "It is a compile-time error to reference a static field
4833             // of an enum type that is not a compile-time constant
4834             // (15.28) from constructors, instance initializer blocks,
4835             // or instance variable initializer expressions of that
4836             // type. It is a compile-time error for the constructors,
4837             // instance initializer blocks, or instance variable
4838             // initializer expressions of an enum constant e to refer
4839             // to itself or to an enum constant of the same type that
4840             // is declared to the right of e."
4841             if (isStaticEnumField(v)) {
4842                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
4843 
4844                 if (enclClass == null || enclClass.owner == null)
4845                     return;
4846 
4847                 // See if the enclosing class is the enum (or a
4848                 // subclass thereof) declaring v.  If not, this
4849                 // reference is OK.
4850                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
4851                     return;
4852 
4853                 // If the reference isn't from an initializer, then
4854                 // the reference is OK.
4855                 if (!Resolve.isInitializer(env))
4856                     return;
4857 
4858                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
4859             }
4860         }
4861 
4862         /** Is the given symbol a static, non-constant field of an Enum?
4863          *  Note: enum literals should not be regarded as such
4864          */
4865         private boolean isStaticEnumField(VarSymbol v) {
4866             return Flags.isEnum(v.owner) &&
4867                    Flags.isStatic(v) &&
4868                    !Flags.isConstant(v) &&
4869                    v.name != names._class;
4870         }
4871 
4872     /**
4873      * Check that method arguments conform to its instantiation.
4874      **/
4875     public Type checkMethod(Type site,
4876                             final Symbol sym,
4877                             ResultInfo resultInfo,
4878                             Env<AttrContext> env,
4879                             final List<JCExpression> argtrees,
4880                             List<Type> argtypes,
4881                             List<Type> typeargtypes) {
4882         // Test (5): if symbol is an instance method of a raw type, issue
4883         // an unchecked warning if its argument types change under erasure.
4884         if ((sym.flags() & STATIC) == 0 &&
4885             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4886             Type s = types.asOuterSuper(site, sym.owner);
4887             if (s != null && s.isRaw() &&
4888                 !types.isSameTypes(sym.type.getParameterTypes(),
4889                                    sym.erasure(types).getParameterTypes())) {
4890                 chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedCallMbrOfRawType(sym, s));
4891             }
4892         }
4893 
4894         if (env.info.defaultSuperCallSite != null) {
4895             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
4896                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
4897                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
4898                 List<MethodSymbol> icand_sup =
4899                         types.interfaceCandidates(sup, (MethodSymbol)sym);
4900                 if (icand_sup.nonEmpty() &&
4901                         icand_sup.head != sym &&
4902                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
4903                     log.error(env.tree.pos(),
4904                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
4905                     break;
4906                 }
4907             }
4908             env.info.defaultSuperCallSite = null;
4909         }
4910 
4911         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
4912             JCMethodInvocation app = (JCMethodInvocation)env.tree;
4913             if (app.meth.hasTag(SELECT) &&
4914                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
4915                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
4916             }
4917         }
4918 
4919         // Compute the identifier's instantiated type.
4920         // For methods, we need to compute the instance type by
4921         // Resolve.instantiate from the symbol's type as well as
4922         // any type arguments and value arguments.
4923         Warner noteWarner = new Warner();
4924         try {
4925             Type owntype = rs.checkMethod(
4926                     env,
4927                     site,
4928                     sym,
4929                     resultInfo,
4930                     argtypes,
4931                     typeargtypes,
4932                     noteWarner);
4933 
4934             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
4935                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
4936 
4937             argtypes = argtypes.map(checkDeferredMap);
4938 
4939             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
4940                 chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedMethInvocationApplied(kindName(sym),
4941                         sym.name,
4942                         rs.methodArguments(sym.type.getParameterTypes()),
4943                         rs.methodArguments(argtypes.map(checkDeferredMap)),
4944                         kindName(sym.location()),
4945                         sym.location()));
4946                 if (resultInfo.pt != Infer.anyPoly ||
4947                         !owntype.hasTag(METHOD) ||
4948                         !owntype.isPartial()) {
4949                     //if this is not a partially inferred method type, erase return type. Otherwise,
4950                     //erasure is carried out in PartiallyInferredMethodType.check().
4951                     owntype = new MethodType(owntype.getParameterTypes(),
4952                             types.erasure(owntype.getReturnType()),
4953                             types.erasure(owntype.getThrownTypes()),
4954                             syms.methodClass);
4955                 }
4956             }
4957 
4958             PolyKind pkind = (sym.type.hasTag(FORALL) &&
4959                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
4960                  PolyKind.POLY : PolyKind.STANDALONE;
4961             TreeInfo.setPolyKind(env.tree, pkind);
4962 
4963             return (resultInfo.pt == Infer.anyPoly) ?
4964                     owntype :
4965                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
4966                             resultInfo.checkContext.inferenceContext());
4967         } catch (Infer.InferenceException ex) {
4968             //invalid target type - propagate exception outwards or report error
4969             //depending on the current check context
4970             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
4971             return types.createErrorType(site);
4972         } catch (Resolve.InapplicableMethodException ex) {
4973             final JCDiagnostic diag = ex.getDiagnostic();
4974             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
4975                 @Override
4976                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4977                     return new Pair<>(sym, diag);
4978                 }
4979             };
4980             List<Type> argtypes2 = argtypes.map(
4981                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
4982             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
4983                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
4984             log.report(errDiag);
4985             return types.createErrorType(site);
4986         }
4987     }
4988 
4989     public void visitLiteral(JCLiteral tree) {
4990         result = check(tree, litType(tree.typetag).constType(tree.value),
4991                 KindSelector.VAL, resultInfo);
4992     }
4993     //where
4994     /** Return the type of a literal with given type tag.
4995      */
4996     Type litType(TypeTag tag) {
4997         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
4998     }
4999 
5000     public void visitStringTemplate(JCStringTemplate tree) {
5001         JCExpression processor = tree.processor;
5002         Type processorType = attribTree(processor, env, new ResultInfo(KindSelector.VAL, Type.noType));
5003         chk.checkProcessorType(processor, processorType, env);
5004         Type processMethodType = getProcessMethodType(tree, processorType);
5005         tree.processMethodType = processMethodType;
5006         Type resultType = processMethodType.getReturnType();
5007 
5008         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
5009 
5010         for (JCExpression arg : tree.expressions) {
5011             chk.checkNonVoid(arg.pos(), attribExpr(arg, localEnv));
5012         }
5013 
5014         tree.type = resultType;
5015         result = resultType;
5016         check(tree, resultType, KindSelector.VAL, resultInfo);
5017     }
5018 
5019     private Type getProcessMethodType(JCStringTemplate tree, Type processorType) {
5020         MethodSymbol processSymbol = rs.resolveInternalMethod(tree.pos(),
5021                 env, types.skipTypeVars(processorType, false),
5022                 names.process, List.of(syms.stringTemplateType), List.nil());
5023         return types.memberType(processorType, processSymbol);
5024     }
5025 
5026     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5027         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5028     }
5029 
5030     public void visitTypeArray(JCArrayTypeTree tree) {
5031         Type etype = attribType(tree.elemtype, env);
5032         Type type = new ArrayType(etype, syms.arrayClass);
5033         result = check(tree, type, KindSelector.TYP, resultInfo);
5034     }
5035 
5036     /** Visitor method for parameterized types.
5037      *  Bound checking is left until later, since types are attributed
5038      *  before supertype structure is completely known
5039      */
5040     public void visitTypeApply(JCTypeApply tree) {
5041         Type owntype = types.createErrorType(tree.type);
5042 
5043         // Attribute functor part of application and make sure it's a class.
5044         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5045 
5046         // Attribute type parameters
5047         List<Type> actuals = attribTypes(tree.arguments, env);
5048 
5049         if (clazztype.hasTag(CLASS)) {
5050             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5051             if (actuals.isEmpty()) //diamond
5052                 actuals = formals;
5053 
5054             if (actuals.length() == formals.length()) {
5055                 List<Type> a = actuals;
5056                 List<Type> f = formals;
5057                 while (a.nonEmpty()) {
5058                     a.head = a.head.withTypeVar(f.head);
5059                     a = a.tail;
5060                     f = f.tail;
5061                 }
5062                 // Compute the proper generic outer
5063                 Type clazzOuter = clazztype.getEnclosingType();
5064                 if (clazzOuter.hasTag(CLASS)) {
5065                     Type site;
5066                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5067                     if (clazz.hasTag(IDENT)) {
5068                         site = env.enclClass.sym.type;
5069                     } else if (clazz.hasTag(SELECT)) {
5070                         site = ((JCFieldAccess) clazz).selected.type;
5071                     } else throw new AssertionError(""+tree);
5072                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5073                         if (site.hasTag(CLASS))
5074                             site = types.asOuterSuper(site, clazzOuter.tsym);
5075                         if (site == null)
5076                             site = types.erasure(clazzOuter);
5077                         clazzOuter = site;
5078                     }
5079                 }
5080                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5081                                         clazztype.getMetadata());
5082             } else {
5083                 if (formals.length() != 0) {
5084                     log.error(tree.pos(),
5085                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5086                 } else {
5087                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5088                 }
5089                 owntype = types.createErrorType(tree.type);
5090             }
5091         }
5092         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5093     }
5094 
5095     public void visitTypeUnion(JCTypeUnion tree) {
5096         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5097         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5098         for (JCExpression typeTree : tree.alternatives) {
5099             Type ctype = attribType(typeTree, env);
5100             ctype = chk.checkType(typeTree.pos(),
5101                           chk.checkClassType(typeTree.pos(), ctype),
5102                           syms.throwableType);
5103             if (!ctype.isErroneous()) {
5104                 //check that alternatives of a union type are pairwise
5105                 //unrelated w.r.t. subtyping
5106                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5107                     for (Type t : multicatchTypes) {
5108                         boolean sub = types.isSubtype(ctype, t);
5109                         boolean sup = types.isSubtype(t, ctype);
5110                         if (sub || sup) {
5111                             //assume 'a' <: 'b'
5112                             Type a = sub ? ctype : t;
5113                             Type b = sub ? t : ctype;
5114                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5115                         }
5116                     }
5117                 }
5118                 multicatchTypes.append(ctype);
5119                 if (all_multicatchTypes != null)
5120                     all_multicatchTypes.append(ctype);
5121             } else {
5122                 if (all_multicatchTypes == null) {
5123                     all_multicatchTypes = new ListBuffer<>();
5124                     all_multicatchTypes.appendList(multicatchTypes);
5125                 }
5126                 all_multicatchTypes.append(ctype);
5127             }
5128         }
5129         Type t = check(tree, types.lub(multicatchTypes.toList()),
5130                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5131         if (t.hasTag(CLASS)) {
5132             List<Type> alternatives =
5133                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5134             t = new UnionClassType((ClassType) t, alternatives);
5135         }
5136         tree.type = result = t;
5137     }
5138 
5139     public void visitTypeIntersection(JCTypeIntersection tree) {
5140         attribTypes(tree.bounds, env);
5141         tree.type = result = checkIntersection(tree, tree.bounds);
5142     }
5143 
5144     public void visitTypeParameter(JCTypeParameter tree) {
5145         TypeVar typeVar = (TypeVar) tree.type;
5146 
5147         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5148             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5149         }
5150 
5151         if (!typeVar.getUpperBound().isErroneous()) {
5152             //fixup type-parameter bound computed in 'attribTypeVariables'
5153             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5154         }
5155     }
5156 
5157     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5158         Set<Symbol> boundSet = new HashSet<>();
5159         if (bounds.nonEmpty()) {
5160             // accept class or interface or typevar as first bound.
5161             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5162             boundSet.add(types.erasure(bounds.head.type).tsym);
5163             if (bounds.head.type.isErroneous()) {
5164                 return bounds.head.type;
5165             }
5166             else if (bounds.head.type.hasTag(TYPEVAR)) {
5167                 // if first bound was a typevar, do not accept further bounds.
5168                 if (bounds.tail.nonEmpty()) {
5169                     log.error(bounds.tail.head.pos(),
5170                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5171                     return bounds.head.type;
5172                 }
5173             } else {
5174                 // if first bound was a class or interface, accept only interfaces
5175                 // as further bounds.
5176                 for (JCExpression bound : bounds.tail) {
5177                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5178                     if (bound.type.isErroneous()) {
5179                         bounds = List.of(bound);
5180                     }
5181                     else if (bound.type.hasTag(CLASS)) {
5182                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5183                     }
5184                 }
5185             }
5186         }
5187 
5188         if (bounds.length() == 0) {
5189             return syms.objectType;
5190         } else if (bounds.length() == 1) {
5191             return bounds.head.type;
5192         } else {
5193             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5194             // ... the variable's bound is a class type flagged COMPOUND
5195             // (see comment for TypeVar.bound).
5196             // In this case, generate a class tree that represents the
5197             // bound class, ...
5198             JCExpression extending;
5199             List<JCExpression> implementing;
5200             if (!bounds.head.type.isInterface()) {
5201                 extending = bounds.head;
5202                 implementing = bounds.tail;
5203             } else {
5204                 extending = null;
5205                 implementing = bounds;
5206             }
5207             JCClassDecl cd = make.at(tree).ClassDef(
5208                 make.Modifiers(PUBLIC | ABSTRACT),
5209                 names.empty, List.nil(),
5210                 extending, implementing, List.nil());
5211 
5212             ClassSymbol c = (ClassSymbol)owntype.tsym;
5213             Assert.check((c.flags() & COMPOUND) != 0);
5214             cd.sym = c;
5215             c.sourcefile = env.toplevel.sourcefile;
5216 
5217             // ... and attribute the bound class
5218             c.flags_field |= UNATTRIBUTED;
5219             Env<AttrContext> cenv = enter.classEnv(cd, env);
5220             typeEnvs.put(c, cenv);
5221             attribClass(c);
5222             return owntype;
5223         }
5224     }
5225 
5226     public void visitWildcard(JCWildcard tree) {
5227         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5228         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5229             ? syms.objectType
5230             : attribType(tree.inner, env);
5231         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
5232                                               tree.kind.kind,
5233                                               syms.boundClass),
5234                 KindSelector.TYP, resultInfo);
5235     }
5236 
5237     public void visitAnnotation(JCAnnotation tree) {
5238         Assert.error("should be handled in annotate");
5239     }
5240 
5241     @Override
5242     public void visitModifiers(JCModifiers tree) {
5243         //error recovery only:
5244         Assert.check(resultInfo.pkind == KindSelector.ERR);
5245 
5246         attribAnnotationTypes(tree.annotations, env);
5247     }
5248 
5249     public void visitAnnotatedType(JCAnnotatedType tree) {
5250         attribAnnotationTypes(tree.annotations, env);
5251         Type underlyingType = attribType(tree.underlyingType, env);
5252         Type annotatedType = underlyingType.preannotatedType();
5253 
5254         if (!env.info.isNewClass)
5255             annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5256         result = tree.type = annotatedType;
5257     }
5258 
5259     public void visitErroneous(JCErroneous tree) {
5260         if (tree.errs != null) {
5261             Env<AttrContext> errEnv = env.dup(env.tree, env.info.dup());
5262             errEnv.info.returnResult = unknownExprInfo;
5263             for (JCTree err : tree.errs)
5264                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5265         }
5266         result = tree.type = syms.errType;
5267     }
5268 
5269     /** Default visitor method for all other trees.
5270      */
5271     public void visitTree(JCTree tree) {
5272         throw new AssertionError();
5273     }
5274 
5275     /**
5276      * Attribute an env for either a top level tree or class or module declaration.
5277      */
5278     public void attrib(Env<AttrContext> env) {
5279         switch (env.tree.getTag()) {
5280             case MODULEDEF:
5281                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5282                 break;
5283             case PACKAGEDEF:
5284                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5285                 break;
5286             default:
5287                 attribClass(env.tree.pos(), env.enclClass.sym);
5288         }
5289     }
5290 
5291     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5292         try {
5293             annotate.flush();
5294             attribPackage(p);
5295         } catch (CompletionFailure ex) {
5296             chk.completionError(pos, ex);
5297         }
5298     }
5299 
5300     void attribPackage(PackageSymbol p) {
5301         attribWithLint(p,
5302                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5303     }
5304 
5305     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5306         try {
5307             annotate.flush();
5308             attribModule(m);
5309         } catch (CompletionFailure ex) {
5310             chk.completionError(pos, ex);
5311         }
5312     }
5313 
5314     void attribModule(ModuleSymbol m) {
5315         attribWithLint(m, env -> attribStat(env.tree, env));
5316     }
5317 
5318     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5319         Env<AttrContext> env = typeEnvs.get(sym);
5320 
5321         Env<AttrContext> lintEnv = env;
5322         while (lintEnv.info.lint == null)
5323             lintEnv = lintEnv.next;
5324 
5325         Lint lint = lintEnv.info.lint.augment(sym);
5326 
5327         Lint prevLint = chk.setLint(lint);
5328         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5329 
5330         try {
5331             deferredLintHandler.flush(env.tree.pos());
5332             attrib.accept(env);
5333         } finally {
5334             log.useSource(prev);
5335             chk.setLint(prevLint);
5336         }
5337     }
5338 
5339     /** Main method: attribute class definition associated with given class symbol.
5340      *  reporting completion failures at the given position.
5341      *  @param pos The source position at which completion errors are to be
5342      *             reported.
5343      *  @param c   The class symbol whose definition will be attributed.
5344      */
5345     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5346         try {
5347             annotate.flush();
5348             attribClass(c);
5349         } catch (CompletionFailure ex) {
5350             chk.completionError(pos, ex);
5351         }
5352     }
5353 
5354     /** Attribute class definition associated with given class symbol.
5355      *  @param c   The class symbol whose definition will be attributed.
5356      */
5357     void attribClass(ClassSymbol c) throws CompletionFailure {
5358         if (c.type.hasTag(ERROR)) return;
5359 
5360         // Check for cycles in the inheritance graph, which can arise from
5361         // ill-formed class files.
5362         chk.checkNonCyclic(null, c.type);
5363 
5364         Type st = types.supertype(c.type);
5365         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5366             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0) {
5367             // First, attribute superclass.
5368             if (st.hasTag(CLASS))
5369                 attribClass((ClassSymbol)st.tsym);
5370 
5371             // Next attribute owner, if it is a class.
5372             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5373                 attribClass((ClassSymbol)c.owner);
5374 
5375             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5376         }
5377 
5378         // The previous operations might have attributed the current class
5379         // if there was a cycle. So we test first whether the class is still
5380         // UNATTRIBUTED.
5381         if ((c.flags_field & UNATTRIBUTED) != 0) {
5382             c.flags_field &= ~UNATTRIBUTED;
5383 
5384             // Get environment current at the point of class definition.
5385             Env<AttrContext> env = typeEnvs.get(c);
5386 
5387             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5388             // because the annotations were not available at the time the env was created. Therefore,
5389             // we look up the environment chain for the first enclosing environment for which the
5390             // lint value is set. Typically, this is the parent env, but might be further if there
5391             // are any envs created as a result of TypeParameter nodes.
5392             Env<AttrContext> lintEnv = env;
5393             while (lintEnv.info.lint == null)
5394                 lintEnv = lintEnv.next;
5395 
5396             // Having found the enclosing lint value, we can initialize the lint value for this class
5397             env.info.lint = lintEnv.info.lint.augment(c);
5398 
5399             Lint prevLint = chk.setLint(env.info.lint);
5400             JavaFileObject prev = log.useSource(c.sourcefile);
5401             ResultInfo prevReturnRes = env.info.returnResult;
5402 
5403             try {
5404                 if (c.isSealed() &&
5405                         !c.isEnum() &&
5406                         !c.isPermittedExplicit &&
5407                         c.permitted.isEmpty()) {
5408                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5409                 }
5410 
5411                 if (c.isSealed()) {
5412                     Set<Symbol> permittedTypes = new HashSet<>();
5413                     boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5414                     for (Symbol subTypeSym : c.permitted) {
5415                         boolean isTypeVar = false;
5416                         if (subTypeSym.type.getTag() == TYPEVAR) {
5417                             isTypeVar = true; //error recovery
5418                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5419                                     Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subTypeSym.type)));
5420                         }
5421                         if (subTypeSym.isAnonymous() && !c.isEnum()) {
5422                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5423                         }
5424                         if (permittedTypes.contains(subTypeSym)) {
5425                             DiagnosticPosition pos =
5426                                     env.enclClass.permitting.stream()
5427                                             .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subTypeSym, permittedExpr, true) != null)
5428                                             .limit(2).collect(List.collector()).get(1);
5429                             log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subTypeSym.type)));
5430                         } else {
5431                             permittedTypes.add(subTypeSym);
5432                         }
5433                         if (sealedInUnnamed) {
5434                             if (subTypeSym.packge() != c.packge()) {
5435                                 log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5436                                         Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5437                                 );
5438                             }
5439                         } else if (subTypeSym.packge().modle != c.packge().modle) {
5440                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5441                                     Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5442                             );
5443                         }
5444                         if (subTypeSym == c.type.tsym || types.isSuperType(subTypeSym.type, c.type)) {
5445                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, ((JCClassDecl)env.tree).permitting),
5446                                     Errors.InvalidPermitsClause(
5447                                             subTypeSym == c.type.tsym ?
5448                                                     Fragments.MustNotBeSameClass :
5449                                                     Fragments.MustNotBeSupertype(subTypeSym.type)
5450                                     )
5451                             );
5452                         } else if (!isTypeVar) {
5453                             boolean thisIsASuper = types.directSupertypes(subTypeSym.type)
5454                                                         .stream()
5455                                                         .anyMatch(d -> d.tsym == c);
5456                             if (!thisIsASuper) {
5457                                 log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5458                                         Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subTypeSym.type)));
5459                             }
5460                         }
5461                     }
5462                 }
5463 
5464                 List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5465                                                       .stream()
5466                                                       .filter(s -> s.tsym.isSealed())
5467                                                       .map(s -> (ClassSymbol) s.tsym)
5468                                                       .collect(List.collector());
5469 
5470                 if (sealedSupers.isEmpty()) {
5471                     if ((c.flags_field & Flags.NON_SEALED) != 0) {
5472                         boolean hasErrorSuper = false;
5473 
5474                         hasErrorSuper |= types.directSupertypes(c.type)
5475                                               .stream()
5476                                               .anyMatch(s -> s.tsym.kind == Kind.ERR);
5477 
5478                         ClassType ct = (ClassType) c.type;
5479 
5480                         hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5481 
5482                         if (!hasErrorSuper) {
5483                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5484                         }
5485                     }
5486                 } else if ((c.flags_field & Flags.COMPOUND) == 0) {
5487                     if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5488                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5489                     }
5490 
5491                     if (!c.type.isCompound()) {
5492                         for (ClassSymbol supertypeSym : sealedSupers) {
5493                             if (!supertypeSym.permitted.contains(c.type.tsym)) {
5494                                 log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5495                             }
5496                         }
5497                         if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5498                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5499                                     c.isInterface() ?
5500                                             Errors.NonSealedOrSealedExpected :
5501                                             Errors.NonSealedSealedOrFinalExpected);
5502                         }
5503                     }
5504                 }
5505 
5506                 deferredLintHandler.flush(env.tree);
5507                 env.info.returnResult = null;
5508                 // java.lang.Enum may not be subclassed by a non-enum
5509                 if (st.tsym == syms.enumSym &&
5510                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5511                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5512 
5513                 // Enums may not be extended by source-level classes
5514                 if (st.tsym != null &&
5515                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5516                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5517                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5518                 }
5519 
5520                 if (rs.isSerializable(c.type)) {
5521                     env.info.isSerializable = true;
5522                 }
5523 
5524                 if (c.isValueClass()) {
5525                     Assert.check(env.tree.hasTag(CLASSDEF));
5526                     chk.checkConstraintsOfValueClass((JCClassDecl) env.tree, c);
5527                 }
5528 
5529                 attribClassBody(env, c);
5530 
5531                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5532                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5533                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5534                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5535 
5536                 if (c.isImplicit()) {
5537                     chk.checkHasMain(env.tree.pos(), c);
5538                 }
5539             } finally {
5540                 env.info.returnResult = prevReturnRes;
5541                 log.useSource(prev);
5542                 chk.setLint(prevLint);
5543             }
5544 
5545         }
5546     }
5547 
5548     public void visitImport(JCImport tree) {
5549         // nothing to do
5550     }
5551 
5552     public void visitModuleDef(JCModuleDecl tree) {
5553         tree.sym.completeUsesProvides();
5554         ModuleSymbol msym = tree.sym;
5555         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5556         Lint prevLint = chk.setLint(lint);
5557         chk.checkModuleName(tree);
5558         chk.checkDeprecatedAnnotation(tree, msym);
5559 
5560         try {
5561             deferredLintHandler.flush(tree.pos());
5562         } finally {
5563             chk.setLint(prevLint);
5564         }
5565     }
5566 
5567     /** Finish the attribution of a class. */
5568     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5569         JCClassDecl tree = (JCClassDecl)env.tree;
5570         Assert.check(c == tree.sym);
5571 
5572         // Validate type parameters, supertype and interfaces.
5573         attribStats(tree.typarams, env);
5574         if (!c.isAnonymous()) {
5575             //already checked if anonymous
5576             chk.validate(tree.typarams, env);
5577             chk.validate(tree.extending, env);
5578             chk.validate(tree.implementing, env);
5579         }
5580 
5581         c.markAbstractIfNeeded(types);
5582 
5583         // If this is a non-abstract class, check that it has no abstract
5584         // methods or unimplemented methods of an implemented interface.
5585         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
5586             chk.checkAllDefined(tree.pos(), c);
5587         }
5588 
5589         if ((c.flags() & ANNOTATION) != 0) {
5590             if (tree.implementing.nonEmpty())
5591                 log.error(tree.implementing.head.pos(),
5592                           Errors.CantExtendIntfAnnotation);
5593             if (tree.typarams.nonEmpty()) {
5594                 log.error(tree.typarams.head.pos(),
5595                           Errors.IntfAnnotationCantHaveTypeParams(c));
5596             }
5597 
5598             // If this annotation type has a @Repeatable, validate
5599             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
5600             // If this annotation type has a @Repeatable, validate
5601             if (repeatable != null) {
5602                 // get diagnostic position for error reporting
5603                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
5604                 Assert.checkNonNull(cbPos);
5605 
5606                 chk.validateRepeatable(c, repeatable, cbPos);
5607             }
5608         } else {
5609             // Check that all extended classes and interfaces
5610             // are compatible (i.e. no two define methods with same arguments
5611             // yet different return types).  (JLS 8.4.8.3)
5612             chk.checkCompatibleSupertypes(tree.pos(), c.type);
5613             chk.checkDefaultMethodClashes(tree.pos(), c.type);
5614             chk.checkPotentiallyAmbiguousOverloads(tree, c.type);
5615         }
5616 
5617         // Check that class does not import the same parameterized interface
5618         // with two different argument lists.
5619         chk.checkClassBounds(tree.pos(), c.type);
5620 
5621         tree.type = c.type;
5622 
5623         for (List<JCTypeParameter> l = tree.typarams;
5624              l.nonEmpty(); l = l.tail) {
5625              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
5626         }
5627 
5628         // Check that a generic class doesn't extend Throwable
5629         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
5630             log.error(tree.extending.pos(), Errors.GenericThrowable);
5631 
5632         // Check that all methods which implement some
5633         // method conform to the method they implement.
5634         chk.checkImplementations(tree);
5635 
5636         //check that a resource implementing AutoCloseable cannot throw InterruptedException
5637         checkAutoCloseable(tree.pos(), env, c.type);
5638 
5639         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
5640             // Attribute declaration
5641             attribStat(l.head, env);
5642             // Check that declarations in inner classes are not static (JLS 8.1.2)
5643             // Make an exception for static constants.
5644             if (!allowRecords &&
5645                     c.owner.kind != PCK &&
5646                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
5647                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
5648                 VarSymbol sym = null;
5649                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
5650                 if (sym == null ||
5651                         sym.kind != VAR ||
5652                         sym.getConstValue() == null)
5653                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
5654             }
5655         }
5656 
5657         // Check for proper placement of super()/this() calls.
5658         chk.checkSuperInitCalls(tree);
5659 
5660         // Check for cycles among non-initial constructors.
5661         chk.checkCyclicConstructors(tree);
5662 
5663         // Check for cycles among annotation elements.
5664         chk.checkNonCyclicElements(tree);
5665 
5666         // Check for proper use of serialVersionUID and other
5667         // serialization-related fields and methods
5668         if (env.info.lint.isEnabled(LintCategory.SERIAL)
5669                 && rs.isSerializable(c.type)
5670                 && !c.isAnonymous()) {
5671             chk.checkSerialStructure(tree, c);
5672         }
5673         // Correctly organize the positions of the type annotations
5674         typeAnnotations.organizeTypeAnnotationsBodies(tree);
5675 
5676         // Check type annotations applicability rules
5677         validateTypeAnnotations(tree, false);
5678     }
5679         // where
5680         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
5681         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
5682             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
5683                 if (types.isSameType(al.head.annotationType.type, t))
5684                     return al.head.pos();
5685             }
5686 
5687             return null;
5688         }
5689 
5690     private Type capture(Type type) {
5691         return types.capture(type);
5692     }
5693 
5694     private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
5695         if (type.isErroneous()) {
5696             tree.vartype = make.at(Position.NOPOS).Erroneous();
5697         } else {
5698             tree.vartype = make.at(Position.NOPOS).Type(type);
5699         }
5700     }
5701 
5702     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
5703         tree.accept(new TypeAnnotationsValidator(sigOnly));
5704     }
5705     //where
5706     private final class TypeAnnotationsValidator extends TreeScanner {
5707 
5708         private final boolean sigOnly;
5709         public TypeAnnotationsValidator(boolean sigOnly) {
5710             this.sigOnly = sigOnly;
5711         }
5712 
5713         public void visitAnnotation(JCAnnotation tree) {
5714             chk.validateTypeAnnotation(tree, null, false);
5715             super.visitAnnotation(tree);
5716         }
5717         public void visitAnnotatedType(JCAnnotatedType tree) {
5718             if (!tree.underlyingType.type.isErroneous()) {
5719                 super.visitAnnotatedType(tree);
5720             }
5721         }
5722         public void visitTypeParameter(JCTypeParameter tree) {
5723             chk.validateTypeAnnotations(tree.annotations, tree.type.tsym, true);
5724             scan(tree.bounds);
5725             // Don't call super.
5726             // This is needed because above we call validateTypeAnnotation with
5727             // false, which would forbid annotations on type parameters.
5728             // super.visitTypeParameter(tree);
5729         }
5730         public void visitMethodDef(JCMethodDecl tree) {
5731             if (tree.recvparam != null &&
5732                     !tree.recvparam.vartype.type.isErroneous()) {
5733                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
5734             }
5735             if (tree.restype != null && tree.restype.type != null) {
5736                 validateAnnotatedType(tree.restype, tree.restype.type);
5737             }
5738             if (sigOnly) {
5739                 scan(tree.mods);
5740                 scan(tree.restype);
5741                 scan(tree.typarams);
5742                 scan(tree.recvparam);
5743                 scan(tree.params);
5744                 scan(tree.thrown);
5745             } else {
5746                 scan(tree.defaultValue);
5747                 scan(tree.body);
5748             }
5749         }
5750         public void visitVarDef(final JCVariableDecl tree) {
5751             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
5752             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
5753                 validateAnnotatedType(tree.vartype, tree.sym.type);
5754             scan(tree.mods);
5755             scan(tree.vartype);
5756             if (!sigOnly) {
5757                 scan(tree.init);
5758             }
5759         }
5760         public void visitTypeCast(JCTypeCast tree) {
5761             if (tree.clazz != null && tree.clazz.type != null)
5762                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5763             super.visitTypeCast(tree);
5764         }
5765         public void visitTypeTest(JCInstanceOf tree) {
5766             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
5767                 validateAnnotatedType(tree.pattern, tree.pattern.type);
5768             super.visitTypeTest(tree);
5769         }
5770         public void visitNewClass(JCNewClass tree) {
5771             if (tree.clazz != null && tree.clazz.type != null) {
5772                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
5773                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
5774                             tree.clazz.type.tsym);
5775                 }
5776                 if (tree.def != null) {
5777                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
5778                 }
5779 
5780                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5781             }
5782             super.visitNewClass(tree);
5783         }
5784         public void visitNewArray(JCNewArray tree) {
5785             if (tree.elemtype != null && tree.elemtype.type != null) {
5786                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
5787                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
5788                             tree.elemtype.type.tsym);
5789                 }
5790                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
5791             }
5792             super.visitNewArray(tree);
5793         }
5794         public void visitClassDef(JCClassDecl tree) {
5795             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
5796             if (sigOnly) {
5797                 scan(tree.mods);
5798                 scan(tree.typarams);
5799                 scan(tree.extending);
5800                 scan(tree.implementing);
5801             }
5802             for (JCTree member : tree.defs) {
5803                 if (member.hasTag(Tag.CLASSDEF)) {
5804                     continue;
5805                 }
5806                 scan(member);
5807             }
5808         }
5809         public void visitBlock(JCBlock tree) {
5810             if (!sigOnly) {
5811                 scan(tree.stats);
5812             }
5813         }
5814 
5815         /* I would want to model this after
5816          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
5817          * and override visitSelect and visitTypeApply.
5818          * However, we only set the annotated type in the top-level type
5819          * of the symbol.
5820          * Therefore, we need to override each individual location where a type
5821          * can occur.
5822          */
5823         private void validateAnnotatedType(final JCTree errtree, final Type type) {
5824             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
5825 
5826             if (type.isPrimitiveOrVoid()) {
5827                 return;
5828             }
5829 
5830             JCTree enclTr = errtree;
5831             Type enclTy = type;
5832 
5833             boolean repeat = true;
5834             while (repeat) {
5835                 if (enclTr.hasTag(TYPEAPPLY)) {
5836                     List<Type> tyargs = enclTy.getTypeArguments();
5837                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
5838                     if (trargs.length() > 0) {
5839                         // Nothing to do for diamonds
5840                         if (tyargs.length() == trargs.length()) {
5841                             for (int i = 0; i < tyargs.length(); ++i) {
5842                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
5843                             }
5844                         }
5845                         // If the lengths don't match, it's either a diamond
5846                         // or some nested type that redundantly provides
5847                         // type arguments in the tree.
5848                     }
5849 
5850                     // Look at the clazz part of a generic type
5851                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
5852                 }
5853 
5854                 if (enclTr.hasTag(SELECT)) {
5855                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
5856                     if (enclTy != null &&
5857                             !enclTy.hasTag(NONE)) {
5858                         enclTy = enclTy.getEnclosingType();
5859                     }
5860                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
5861                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
5862                     if (enclTy == null || enclTy.hasTag(NONE)) {
5863                         if (at.getAnnotations().size() == 1) {
5864                             log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping1(at.getAnnotations().head.attribute));
5865                         } else {
5866                             ListBuffer<Attribute.Compound> comps = new ListBuffer<>();
5867                             for (JCAnnotation an : at.getAnnotations()) {
5868                                 comps.add(an.attribute);
5869                             }
5870                             log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping(comps.toList()));
5871                         }
5872                         repeat = false;
5873                     }
5874                     enclTr = at.underlyingType;
5875                     // enclTy doesn't need to be changed
5876                 } else if (enclTr.hasTag(IDENT)) {
5877                     repeat = false;
5878                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
5879                     JCWildcard wc = (JCWildcard) enclTr;
5880                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
5881                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
5882                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
5883                     } else {
5884                         // Nothing to do for UNBOUND
5885                     }
5886                     repeat = false;
5887                 } else if (enclTr.hasTag(TYPEARRAY)) {
5888                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
5889                     validateAnnotatedType(art.getType(), art.elemtype.type);
5890                     repeat = false;
5891                 } else if (enclTr.hasTag(TYPEUNION)) {
5892                     JCTypeUnion ut = (JCTypeUnion) enclTr;
5893                     for (JCTree t : ut.getTypeAlternatives()) {
5894                         validateAnnotatedType(t, t.type);
5895                     }
5896                     repeat = false;
5897                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
5898                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
5899                     for (JCTree t : it.getBounds()) {
5900                         validateAnnotatedType(t, t.type);
5901                     }
5902                     repeat = false;
5903                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
5904                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
5905                     repeat = false;
5906                 } else {
5907                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
5908                             " within: "+ errtree + " with kind: " + errtree.getKind());
5909                 }
5910             }
5911         }
5912 
5913         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
5914                 Symbol sym) {
5915             // Ensure that no declaration annotations are present.
5916             // Note that a tree type might be an AnnotatedType with
5917             // empty annotations, if only declaration annotations were given.
5918             // This method will raise an error for such a type.
5919             for (JCAnnotation ai : annotations) {
5920                 if (!ai.type.isErroneous() &&
5921                         typeAnnotations.annotationTargetType(ai, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
5922                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
5923                 }
5924             }
5925         }
5926     }
5927 
5928     // <editor-fold desc="post-attribution visitor">
5929 
5930     /**
5931      * Handle missing types/symbols in an AST. This routine is useful when
5932      * the compiler has encountered some errors (which might have ended up
5933      * terminating attribution abruptly); if the compiler is used in fail-over
5934      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
5935      * prevents NPE to be propagated during subsequent compilation steps.
5936      */
5937     public void postAttr(JCTree tree) {
5938         new PostAttrAnalyzer().scan(tree);
5939     }
5940 
5941     class PostAttrAnalyzer extends TreeScanner {
5942 
5943         private void initTypeIfNeeded(JCTree that) {
5944             if (that.type == null) {
5945                 if (that.hasTag(METHODDEF)) {
5946                     that.type = dummyMethodType((JCMethodDecl)that);
5947                 } else {
5948                     that.type = syms.unknownType;
5949                 }
5950             }
5951         }
5952 
5953         /* Construct a dummy method type. If we have a method declaration,
5954          * and the declared return type is void, then use that return type
5955          * instead of UNKNOWN to avoid spurious error messages in lambda
5956          * bodies (see:JDK-8041704).
5957          */
5958         private Type dummyMethodType(JCMethodDecl md) {
5959             Type restype = syms.unknownType;
5960             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
5961                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
5962                 if (prim.typetag == VOID)
5963                     restype = syms.voidType;
5964             }
5965             return new MethodType(List.nil(), restype,
5966                                   List.nil(), syms.methodClass);
5967         }
5968         private Type dummyMethodType() {
5969             return dummyMethodType(null);
5970         }
5971 
5972         @Override
5973         public void scan(JCTree tree) {
5974             if (tree == null) return;
5975             if (tree instanceof JCExpression) {
5976                 initTypeIfNeeded(tree);
5977             }
5978             super.scan(tree);
5979         }
5980 
5981         @Override
5982         public void visitIdent(JCIdent that) {
5983             if (that.sym == null) {
5984                 that.sym = syms.unknownSymbol;
5985             }
5986         }
5987 
5988         @Override
5989         public void visitSelect(JCFieldAccess that) {
5990             if (that.sym == null) {
5991                 that.sym = syms.unknownSymbol;
5992             }
5993             super.visitSelect(that);
5994         }
5995 
5996         @Override
5997         public void visitClassDef(JCClassDecl that) {
5998             initTypeIfNeeded(that);
5999             if (that.sym == null) {
6000                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
6001             }
6002             super.visitClassDef(that);
6003         }
6004 
6005         @Override
6006         public void visitMethodDef(JCMethodDecl that) {
6007             initTypeIfNeeded(that);
6008             if (that.sym == null) {
6009                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
6010             }
6011             super.visitMethodDef(that);
6012         }
6013 
6014         @Override
6015         public void visitVarDef(JCVariableDecl that) {
6016             initTypeIfNeeded(that);
6017             if (that.sym == null) {
6018                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
6019                 that.sym.adr = 0;
6020             }
6021             if (that.vartype == null) {
6022                 that.vartype = make.at(Position.NOPOS).Erroneous();
6023             }
6024             super.visitVarDef(that);
6025         }
6026 
6027         @Override
6028         public void visitBindingPattern(JCBindingPattern that) {
6029             initTypeIfNeeded(that);
6030             initTypeIfNeeded(that.var);
6031             if (that.var.sym == null) {
6032                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6033                 that.var.sym.adr = 0;
6034             }
6035             super.visitBindingPattern(that);
6036         }
6037 
6038         @Override
6039         public void visitNewClass(JCNewClass that) {
6040             if (that.constructor == null) {
6041                 that.constructor = new MethodSymbol(0, names.init,
6042                         dummyMethodType(), syms.noSymbol);
6043             }
6044             if (that.constructorType == null) {
6045                 that.constructorType = syms.unknownType;
6046             }
6047             super.visitNewClass(that);
6048         }
6049 
6050         @Override
6051         public void visitAssignop(JCAssignOp that) {
6052             if (that.operator == null) {
6053                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6054                         -1, syms.noSymbol);
6055             }
6056             super.visitAssignop(that);
6057         }
6058 
6059         @Override
6060         public void visitBinary(JCBinary that) {
6061             if (that.operator == null) {
6062                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6063                         -1, syms.noSymbol);
6064             }
6065             super.visitBinary(that);
6066         }
6067 
6068         @Override
6069         public void visitUnary(JCUnary that) {
6070             if (that.operator == null) {
6071                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6072                         -1, syms.noSymbol);
6073             }
6074             super.visitUnary(that);
6075         }
6076 
6077         @Override
6078         public void visitReference(JCMemberReference that) {
6079             super.visitReference(that);
6080             if (that.sym == null) {
6081                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6082                         syms.noSymbol);
6083             }
6084         }
6085     }
6086     // </editor-fold>
6087 
6088     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6089         new TreeScanner() {
6090             Symbol packge = pkg;
6091             @Override
6092             public void visitIdent(JCIdent that) {
6093                 that.sym = packge;
6094             }
6095 
6096             @Override
6097             public void visitSelect(JCFieldAccess that) {
6098                 that.sym = packge;
6099                 packge = packge.owner;
6100                 super.visitSelect(that);
6101             }
6102         }.scan(pid);
6103     }
6104 
6105 }
--- EOF ---