1 /*
   2  * Copyright (c) 1999, 2022, 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.EnhancedForLoopTree;
  38 import com.sun.source.tree.IdentifierTree;
  39 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
  40 import com.sun.source.tree.MemberSelectTree;
  41 import com.sun.source.tree.TreeVisitor;
  42 import com.sun.source.util.SimpleTreeVisitor;
  43 import com.sun.tools.javac.code.*;
  44 import com.sun.tools.javac.code.Lint.LintCategory;
  45 import com.sun.tools.javac.code.Scope.WriteableScope;
  46 import com.sun.tools.javac.code.Source.Feature;
  47 import com.sun.tools.javac.code.Symbol.*;
  48 import com.sun.tools.javac.code.Type.*;
  49 import com.sun.tools.javac.code.Type.ClassType.Flavor;
  50 import com.sun.tools.javac.code.TypeMetadata.Annotations;
  51 import com.sun.tools.javac.code.Types.FunctionDescriptorLookupError;
  52 import com.sun.tools.javac.comp.ArgumentAttr.LocalCacheContext;
  53 import com.sun.tools.javac.comp.Check.CheckContext;
  54 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
  55 import com.sun.tools.javac.comp.MatchBindingsComputer.MatchBindings;
  56 import com.sun.tools.javac.jvm.*;
  57 
  58 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
  59 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
  60 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
  61 
  62 import com.sun.tools.javac.resources.CompilerProperties.Errors;
  63 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  64 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
  65 import com.sun.tools.javac.tree.*;
  66 import com.sun.tools.javac.tree.JCTree.*;
  67 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
  68 import com.sun.tools.javac.util.*;
  69 import com.sun.tools.javac.util.DefinedBy.Api;
  70 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  71 import com.sun.tools.javac.util.JCDiagnostic.Error;
  72 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
  73 import com.sun.tools.javac.util.JCDiagnostic.Warning;
  74 import com.sun.tools.javac.util.List;
  75 
  76 import static com.sun.tools.javac.code.Flags.*;
  77 import static com.sun.tools.javac.code.Flags.ANNOTATION;
  78 import static com.sun.tools.javac.code.Flags.BLOCK;
  79 import static com.sun.tools.javac.code.Kinds.*;
  80 import static com.sun.tools.javac.code.Kinds.Kind.*;
  81 import static com.sun.tools.javac.code.TypeTag.*;
  82 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
  83 import static com.sun.tools.javac.tree.JCTree.Tag.*;
  84 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
  85 
  86 /** This is the main context-dependent analysis phase in GJC. It
  87  *  encompasses name resolution, type checking and constant folding as
  88  *  subtasks. Some subtasks involve auxiliary classes.
  89  *  @see Check
  90  *  @see Resolve
  91  *  @see ConstFold
  92  *  @see Infer
  93  *
  94  *  <p><b>This is NOT part of any supported API.
  95  *  If you write code that depends on this, you do so at your own risk.
  96  *  This code and its internal interfaces are subject to change or
  97  *  deletion without notice.</b>
  98  */
  99 public class Attr extends JCTree.Visitor {
 100     protected static final Context.Key<Attr> attrKey = new Context.Key<>();
 101 
 102     final Names names;
 103     final Log log;
 104     final Symtab syms;
 105     final Resolve rs;
 106     final Operators operators;
 107     final Infer infer;
 108     final Analyzer analyzer;
 109     final DeferredAttr deferredAttr;
 110     final Check chk;
 111     final Flow flow;
 112     final MemberEnter memberEnter;
 113     final TypeEnter typeEnter;
 114     final TreeMaker make;
 115     final ConstFold cfolder;
 116     final Enter enter;
 117     final Target target;
 118     final Types types;
 119     final Preview preview;
 120     final JCDiagnostic.Factory diags;
 121     final TypeAnnotations typeAnnotations;
 122     final DeferredLintHandler deferredLintHandler;
 123     final TypeEnvs typeEnvs;
 124     final Dependencies dependencies;
 125     final Annotate annotate;
 126     final ArgumentAttr argumentAttr;
 127     final MatchBindingsComputer matchBindingsComputer;
 128     final AttrRecover attrRecover;
 129 
 130     public static Attr instance(Context context) {
 131         Attr instance = context.get(attrKey);
 132         if (instance == null)
 133             instance = new Attr(context);
 134         return instance;
 135     }
 136 
 137     protected Attr(Context context) {
 138         context.put(attrKey, this);
 139 
 140         names = Names.instance(context);
 141         log = Log.instance(context);
 142         syms = Symtab.instance(context);
 143         rs = Resolve.instance(context);
 144         operators = Operators.instance(context);
 145         chk = Check.instance(context);
 146         flow = Flow.instance(context);
 147         memberEnter = MemberEnter.instance(context);
 148         typeEnter = TypeEnter.instance(context);
 149         make = TreeMaker.instance(context);
 150         enter = Enter.instance(context);
 151         infer = Infer.instance(context);
 152         analyzer = Analyzer.instance(context);
 153         deferredAttr = DeferredAttr.instance(context);
 154         cfolder = ConstFold.instance(context);
 155         target = Target.instance(context);
 156         types = Types.instance(context);
 157         preview = Preview.instance(context);
 158         diags = JCDiagnostic.Factory.instance(context);
 159         annotate = Annotate.instance(context);
 160         typeAnnotations = TypeAnnotations.instance(context);
 161         deferredLintHandler = DeferredLintHandler.instance(context);
 162         typeEnvs = TypeEnvs.instance(context);
 163         dependencies = Dependencies.instance(context);
 164         argumentAttr = ArgumentAttr.instance(context);
 165         matchBindingsComputer = MatchBindingsComputer.instance(context);
 166         attrRecover = AttrRecover.instance(context);
 167 
 168         Options options = Options.instance(context);
 169 
 170         Source source = Source.instance(context);
 171         allowPrimitiveClasses = Feature.PRIMITIVE_CLASSES.allowedInSource(source) && options.isSet("enablePrimitiveClasses");
 172         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 173         allowRecords = Feature.RECORDS.allowedInSource(source);
 174         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 175                              Feature.PATTERN_SWITCH.allowedInSource(source);
 176         allowUnconditionalPatternsInstanceOf = (preview.isEnabled() || !preview.isPreview(Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF)) &&
 177                                      Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 178         sourceName = source.name;
 179         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 180 
 181         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 182         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 183         unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
 184         methodAttrInfo = new MethodAttrInfo();
 185         unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
 186         unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
 187         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
 188     }
 189 
 190     /** Switch: allow primitive classes ?
 191      */
 192     boolean allowPrimitiveClasses;
 193 
 194     /** Switch: reifiable types in instanceof enabled?
 195      */
 196     boolean allowReifiableTypesInInstanceof;
 197 
 198     /** Are records allowed
 199      */
 200     private final boolean allowRecords;
 201 
 202     /** Are patterns in switch allowed
 203      */
 204     private final boolean allowPatternSwitch;
 205 
 206     /** Are unconditional patterns in instanceof allowed
 207      */
 208     private final boolean allowUnconditionalPatternsInstanceOf;
 209 
 210     /**
 211      * Switch: warn about use of variable before declaration?
 212      * RFE: 6425594
 213      */
 214     boolean useBeforeDeclarationWarning;
 215 
 216     /**
 217      * Switch: name of source level; used for error reporting.
 218      */
 219     String sourceName;
 220 
 221     /** Check kind and type of given tree against protokind and prototype.
 222      *  If check succeeds, store type in tree and return it.
 223      *  If check fails, store errType in tree and return it.
 224      *  No checks are performed if the prototype is a method type.
 225      *  It is not necessary in this case since we know that kind and type
 226      *  are correct.
 227      *
 228      *  @param tree     The tree whose kind and type is checked
 229      *  @param found    The computed type of the tree
 230      *  @param ownkind  The computed kind of the tree
 231      *  @param resultInfo  The expected result of the tree
 232      */
 233     Type check(final JCTree tree,
 234                final Type found,
 235                final KindSelector ownkind,
 236                final ResultInfo resultInfo) {
 237         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 238         Type owntype;
 239         boolean shouldCheck = !found.hasTag(ERROR) &&
 240                 !resultInfo.pt.hasTag(METHOD) &&
 241                 !resultInfo.pt.hasTag(FORALL);
 242         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 243             log.error(tree.pos(),
 244                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 245                                             ownkind.kindNames()));
 246             owntype = types.createErrorType(found);
 247         } else if (inferenceContext.free(found)) {
 248             //delay the check if there are inference variables in the found type
 249             //this means we are dealing with a partially inferred poly expression
 250             owntype = shouldCheck ? resultInfo.pt : found;
 251             if (resultInfo.checkMode.installPostInferenceHook()) {
 252                 inferenceContext.addFreeTypeListener(List.of(found),
 253                         instantiatedContext -> {
 254                             ResultInfo pendingResult =
 255                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 256                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 257                         });
 258             }
 259         } else {
 260             owntype = shouldCheck ?
 261             resultInfo.check(tree, found) :
 262             found;
 263         }
 264         if (resultInfo.checkMode.updateTreeType()) {
 265             tree.type = owntype;
 266         }
 267         return owntype;
 268     }
 269 
 270     /** Is given blank final variable assignable, i.e. in a scope where it
 271      *  may be assigned to even though it is final?
 272      *  @param v      The blank final variable.
 273      *  @param env    The current environment.
 274      */
 275     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 276         Symbol owner = env.info.scope.owner;
 277            // owner refers to the innermost variable, method or
 278            // initializer block declaration at this point.
 279         boolean isAssignable =
 280             v.owner == owner
 281             ||
 282             ((names.isInitOrVNew(owner.name) ||    // i.e. we are in a constructor
 283               owner.kind == VAR ||           // i.e. we are in a variable initializer
 284               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 285              &&
 286              v.owner == owner.owner
 287              &&
 288              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 289         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 290         return isAssignable & !insideCompactConstructor;
 291     }
 292 
 293     /** Check that variable can be assigned to.
 294      *  @param pos    The current source code position.
 295      *  @param v      The assigned variable
 296      *  @param base   If the variable is referred to in a Select, the part
 297      *                to the left of the `.', null otherwise.
 298      *  @param env    The current environment.
 299      */
 300     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 301         if (v.name == names._this) {
 302             log.error(pos, Errors.CantAssignValToThis);
 303         } else if ((v.flags() & FINAL) != 0 &&
 304             ((v.flags() & HASINIT) != 0
 305              ||
 306              !((base == null ||
 307                TreeInfo.isThisQualifier(base)) &&
 308                isAssignableAsBlankFinal(v, env)))) {
 309             if (v.isResourceVariable()) { //TWR resource
 310                 log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
 311             } else {
 312                 log.error(pos, Errors.CantAssignValToFinalVar(v));
 313             }
 314         }
 315     }
 316 
 317     /** Does tree represent a static reference to an identifier?
 318      *  It is assumed that tree is either a SELECT or an IDENT.
 319      *  We have to weed out selects from non-type names here.
 320      *  @param tree    The candidate tree.
 321      */
 322     boolean isStaticReference(JCTree tree) {
 323         if (tree.hasTag(SELECT)) {
 324             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 325             if (lsym == null || lsym.kind != TYP) {
 326                 return false;
 327             }
 328         }
 329         return true;
 330     }
 331 
 332     /** Is this symbol a type?
 333      */
 334     static boolean isType(Symbol sym) {
 335         return sym != null && sym.kind == TYP;
 336     }
 337 
 338     /** The current `this' symbol.
 339      *  @param env    The current environment.
 340      */
 341     Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
 342         return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
 343     }
 344 
 345     /** Attribute a parsed identifier.
 346      * @param tree Parsed identifier name
 347      * @param topLevel The toplevel to use
 348      */
 349     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 350         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 351         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 352                                            syms.errSymbol.name,
 353                                            null, null, null, null);
 354         localEnv.enclClass.sym = syms.errSymbol;
 355         return attribIdent(tree, localEnv);
 356     }
 357 
 358     /** Attribute a parsed identifier.
 359      * @param tree Parsed identifier name
 360      * @param env The env to use
 361      */
 362     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 363         return tree.accept(identAttributer, env);
 364     }
 365     // where
 366         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 367         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 368             @Override @DefinedBy(Api.COMPILER_TREE)
 369             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 370                 Symbol site = visit(node.getExpression(), env);
 371                 if (site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 372                     return site;
 373                 Name name = (Name)node.getIdentifier();
 374                 if (site.kind == PCK) {
 375                     env.toplevel.packge = (PackageSymbol)site;
 376                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 377                             KindSelector.TYP_PCK);
 378                 } else {
 379                     env.enclClass.sym = (ClassSymbol)site;
 380                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 381                 }
 382             }
 383 
 384             @Override @DefinedBy(Api.COMPILER_TREE)
 385             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 386                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 387             }
 388         }
 389 
 390     public Type coerce(Type etype, Type ttype) {
 391         return cfolder.coerce(etype, ttype);
 392     }
 393 
 394     public Type attribType(JCTree node, TypeSymbol sym) {
 395         Env<AttrContext> env = typeEnvs.get(sym);
 396         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 397         return attribTree(node, localEnv, unknownTypeInfo);
 398     }
 399 
 400     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 401         // Attribute qualifying package or class.
 402         JCFieldAccess s = (JCFieldAccess)tree.qualid;
 403         return attribTree(s.selected, env,
 404                           new ResultInfo(tree.staticImport ?
 405                                          KindSelector.TYP : KindSelector.TYP_PCK,
 406                        Type.noType));
 407     }
 408 
 409     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 410         return attribToTree(expr, env, tree, unknownExprInfo);
 411     }
 412 
 413     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 414         return attribToTree(stmt, env, tree, statInfo);
 415     }
 416 
 417     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 418         breakTree = tree;
 419         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 420         try {
 421             deferredAttr.attribSpeculative(root, env, resultInfo,
 422                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 423                     argumentAttr.withLocalCacheContext());
 424             attrRecover.doRecovery();
 425         } catch (BreakAttr b) {
 426             return b.env;
 427         } catch (AssertionError ae) {
 428             if (ae.getCause() instanceof BreakAttr breakAttr) {
 429                 return breakAttr.env;
 430             } else {
 431                 throw ae;
 432             }
 433         } finally {
 434             breakTree = null;
 435             log.useSource(prev);
 436         }
 437         return env;
 438     }
 439 
 440     private JCTree breakTree = null;
 441 
 442     private static class BreakAttr extends RuntimeException {
 443         static final long serialVersionUID = -6924771130405446405L;
 444         private transient Env<AttrContext> env;
 445         private BreakAttr(Env<AttrContext> env) {
 446             this.env = env;
 447         }
 448     }
 449 
 450     /**
 451      * Mode controlling behavior of Attr.Check
 452      */
 453     enum CheckMode {
 454 
 455         NORMAL,
 456 
 457         /**
 458          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 459          * that the captured var cache in {@code InferenceContext} will be used in read-only
 460          * mode when performing inference checks.
 461          */
 462         NO_TREE_UPDATE {
 463             @Override
 464             public boolean updateTreeType() {
 465                 return false;
 466             }
 467         },
 468         /**
 469          * Mode signalling that caller will manage free types in tree decorations.
 470          */
 471         NO_INFERENCE_HOOK {
 472             @Override
 473             public boolean installPostInferenceHook() {
 474                 return false;
 475             }
 476         };
 477 
 478         public boolean updateTreeType() {
 479             return true;
 480         }
 481         public boolean installPostInferenceHook() {
 482             return true;
 483         }
 484     }
 485 
 486 
 487     class ResultInfo {
 488         final KindSelector pkind;
 489         final Type pt;
 490         final CheckContext checkContext;
 491         final CheckMode checkMode;
 492 
 493         ResultInfo(KindSelector pkind, Type pt) {
 494             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 495         }
 496 
 497         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 498             this(pkind, pt, chk.basicHandler, checkMode);
 499         }
 500 
 501         protected ResultInfo(KindSelector pkind,
 502                              Type pt, CheckContext checkContext) {
 503             this(pkind, pt, checkContext, CheckMode.NORMAL);
 504         }
 505 
 506         protected ResultInfo(KindSelector pkind,
 507                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 508             this.pkind = pkind;
 509             this.pt = pt;
 510             this.checkContext = checkContext;
 511             this.checkMode = checkMode;
 512         }
 513 
 514         /**
 515          * Should {@link Attr#attribTree} use the {@ArgumentAttr} visitor instead of this one?
 516          * @param tree The tree to be type-checked.
 517          * @return true if {@ArgumentAttr} should be used.
 518          */
 519         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 520 
 521         protected Type check(final DiagnosticPosition pos, final Type found) {
 522             return chk.checkType(pos, found, pt, checkContext);
 523         }
 524 
 525         protected ResultInfo dup(Type newPt) {
 526             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 527         }
 528 
 529         protected ResultInfo dup(CheckContext newContext) {
 530             return new ResultInfo(pkind, pt, newContext, checkMode);
 531         }
 532 
 533         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 534             return new ResultInfo(pkind, newPt, newContext, checkMode);
 535         }
 536 
 537         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 538             return new ResultInfo(pkind, newPt, newContext, newMode);
 539         }
 540 
 541         protected ResultInfo dup(CheckMode newMode) {
 542             return new ResultInfo(pkind, pt, checkContext, newMode);
 543         }
 544 
 545         @Override
 546         public String toString() {
 547             if (pt != null) {
 548                 return pt.toString();
 549             } else {
 550                 return "";
 551             }
 552         }
 553     }
 554 
 555     class MethodAttrInfo extends ResultInfo {
 556         public MethodAttrInfo() {
 557             this(chk.basicHandler);
 558         }
 559 
 560         public MethodAttrInfo(CheckContext checkContext) {
 561             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 562         }
 563 
 564         @Override
 565         protected boolean needsArgumentAttr(JCTree tree) {
 566             return true;
 567         }
 568 
 569         protected ResultInfo dup(Type newPt) {
 570             throw new IllegalStateException();
 571         }
 572 
 573         protected ResultInfo dup(CheckContext newContext) {
 574             return new MethodAttrInfo(newContext);
 575         }
 576 
 577         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 578             throw new IllegalStateException();
 579         }
 580 
 581         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 582             throw new IllegalStateException();
 583         }
 584 
 585         protected ResultInfo dup(CheckMode newMode) {
 586             throw new IllegalStateException();
 587         }
 588     }
 589 
 590     class RecoveryInfo extends ResultInfo {
 591 
 592         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 593             this(deferredAttrContext, Type.recoveryType);
 594         }
 595 
 596         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 597             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 598                 @Override
 599                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 600                     return deferredAttrContext;
 601                 }
 602                 @Override
 603                 public boolean compatible(Type found, Type req, Warner warn) {
 604                     return true;
 605                 }
 606                 @Override
 607                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 608                     boolean needsReport = pt == Type.recoveryType ||
 609                             (details.getDiagnosticPosition() != null &&
 610                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 611                     if (needsReport) {
 612                         chk.basicHandler.report(pos, details);
 613                     }
 614                 }
 615             });
 616         }
 617     }
 618 
 619     final ResultInfo statInfo;
 620     final ResultInfo varAssignmentInfo;
 621     final ResultInfo methodAttrInfo;
 622     final ResultInfo unknownExprInfo;
 623     final ResultInfo unknownTypeInfo;
 624     final ResultInfo unknownTypeExprInfo;
 625     final ResultInfo recoveryInfo;
 626 
 627     Type pt() {
 628         return resultInfo.pt;
 629     }
 630 
 631     KindSelector pkind() {
 632         return resultInfo.pkind;
 633     }
 634 
 635 /* ************************************************************************
 636  * Visitor methods
 637  *************************************************************************/
 638 
 639     /** Visitor argument: the current environment.
 640      */
 641     Env<AttrContext> env;
 642 
 643     /** Visitor argument: the currently expected attribution result.
 644      */
 645     ResultInfo resultInfo;
 646 
 647     /** Visitor result: the computed type.
 648      */
 649     Type result;
 650 
 651     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 652 
 653     /** Visitor method: attribute a tree, catching any completion failure
 654      *  exceptions. Return the tree's type.
 655      *
 656      *  @param tree    The tree to be visited.
 657      *  @param env     The environment visitor argument.
 658      *  @param resultInfo   The result info visitor argument.
 659      */
 660     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 661         Env<AttrContext> prevEnv = this.env;
 662         ResultInfo prevResult = this.resultInfo;
 663         try {
 664             this.env = env;
 665             this.resultInfo = resultInfo;
 666             if (resultInfo.needsArgumentAttr(tree)) {
 667                 result = argumentAttr.attribArg(tree, env);
 668             } else {
 669                 tree.accept(this);
 670             }
 671             matchBindings = matchBindingsComputer.finishBindings(tree,
 672                                                                  matchBindings);
 673             if (tree == breakTree &&
 674                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 675                 breakTreeFound(copyEnv(env));
 676             }
 677             return result;
 678         } catch (CompletionFailure ex) {
 679             tree.type = syms.errType;
 680             return chk.completionError(tree.pos(), ex);
 681         } finally {
 682             this.env = prevEnv;
 683             this.resultInfo = prevResult;
 684         }
 685     }
 686 
 687     protected void breakTreeFound(Env<AttrContext> env) {
 688         throw new BreakAttr(env);
 689     }
 690 
 691     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 692         Env<AttrContext> newEnv =
 693                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 694         if (newEnv.outer != null) {
 695             newEnv.outer = copyEnv(newEnv.outer);
 696         }
 697         return newEnv;
 698     }
 699 
 700     WriteableScope copyScope(WriteableScope sc) {
 701         WriteableScope newScope = WriteableScope.create(sc.owner);
 702         List<Symbol> elemsList = List.nil();
 703         for (Symbol sym : sc.getSymbols()) {
 704             elemsList = elemsList.prepend(sym);
 705         }
 706         for (Symbol s : elemsList) {
 707             newScope.enter(s);
 708         }
 709         return newScope;
 710     }
 711 
 712     /** Derived visitor method: attribute an expression tree.
 713      */
 714     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 715         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 716     }
 717 
 718     /** Derived visitor method: attribute an expression tree with
 719      *  no constraints on the computed type.
 720      */
 721     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 722         return attribTree(tree, env, unknownExprInfo);
 723     }
 724 
 725     /** Derived visitor method: attribute a type tree.
 726      */
 727     public Type attribType(JCTree tree, Env<AttrContext> env) {
 728         Type result = attribType(tree, env, Type.noType);
 729         return result;
 730     }
 731 
 732     /** Derived visitor method: attribute a type tree.
 733      */
 734     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 735         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 736         return result;
 737     }
 738 
 739     /** Derived visitor method: attribute a statement or definition tree.
 740      */
 741     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 742         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 743         Type result = attribTree(tree, env, statInfo);
 744         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 745         attrRecover.doRecovery();
 746         return result;
 747     }
 748 
 749     /** Attribute a list of expressions, returning a list of types.
 750      */
 751     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 752         ListBuffer<Type> ts = new ListBuffer<>();
 753         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 754             ts.append(attribExpr(l.head, env, pt));
 755         return ts.toList();
 756     }
 757 
 758     /** Attribute a list of statements, returning nothing.
 759      */
 760     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 761         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 762             attribStat(l.head, env);
 763     }
 764 
 765     /** Attribute the arguments in a method call, returning the method kind.
 766      */
 767     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 768         KindSelector kind = initialKind;
 769         for (JCExpression arg : trees) {
 770             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 771             if (argtype.hasTag(DEFERRED)) {
 772                 kind = KindSelector.of(KindSelector.POLY, kind);
 773             }
 774             argtypes.append(argtype);
 775         }
 776         return kind;
 777     }
 778 
 779     /** Attribute a type argument list, returning a list of types.
 780      *  Caller is responsible for calling checkRefTypes.
 781      */
 782     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 783         ListBuffer<Type> argtypes = new ListBuffer<>();
 784         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 785             argtypes.append(attribType(l.head, env));
 786         return argtypes.toList();
 787     }
 788 
 789     /** Attribute a type argument list, returning a list of types.
 790      *  Check that all the types are references.
 791      */
 792     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 793         List<Type> types = attribAnyTypes(trees, env);
 794         return chk.checkRefTypes(trees, types);
 795     }
 796 
 797     /**
 798      * Attribute type variables (of generic classes or methods).
 799      * Compound types are attributed later in attribBounds.
 800      * @param typarams the type variables to enter
 801      * @param env      the current environment
 802      */
 803     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 804         for (JCTypeParameter tvar : typarams) {
 805             TypeVar a = (TypeVar)tvar.type;
 806             a.tsym.flags_field |= UNATTRIBUTED;
 807             a.setUpperBound(Type.noType);
 808             if (!tvar.bounds.isEmpty()) {
 809                 List<Type> bounds = List.of(chk.checkRefType(tvar.bounds.head, attribType(tvar.bounds.head, env), false));
 810                 for (JCExpression bound : tvar.bounds.tail)
 811                     bounds = bounds.prepend(chk.checkRefType(bound, attribType(bound, env), false));
 812                 types.setBounds(a, bounds.reverse());
 813             } else {
 814                 // if no bounds are given, assume a single bound of
 815                 // java.lang.Object.
 816                 types.setBounds(a, List.of(syms.objectType));
 817             }
 818             a.tsym.flags_field &= ~UNATTRIBUTED;
 819         }
 820         if (checkCyclic) {
 821             for (JCTypeParameter tvar : typarams) {
 822                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 823             }
 824         }
 825     }
 826 
 827     /**
 828      * Attribute the type references in a list of annotations.
 829      */
 830     void attribAnnotationTypes(List<JCAnnotation> annotations,
 831                                Env<AttrContext> env) {
 832         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 833             JCAnnotation a = al.head;
 834             attribType(a.annotationType, env);
 835         }
 836     }
 837 
 838     /**
 839      * Attribute a "lazy constant value".
 840      *  @param env         The env for the const value
 841      *  @param variable    The initializer for the const value
 842      *  @param type        The expected type, or null
 843      *  @see VarSymbol#setLazyConstValue
 844      */
 845     public Object attribLazyConstantValue(Env<AttrContext> env,
 846                                       JCVariableDecl variable,
 847                                       Type type) {
 848 
 849         DiagnosticPosition prevLintPos
 850                 = deferredLintHandler.setPos(variable.pos());
 851 
 852         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 853         try {
 854             Type itype = attribExpr(variable.init, env, type);
 855             if (variable.isImplicitlyTyped()) {
 856                 //fixup local variable type
 857                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 858             }
 859             if (itype.constValue() != null) {
 860                 return coerce(itype, type).constValue();
 861             } else {
 862                 return null;
 863             }
 864         } finally {
 865             log.useSource(prevSource);
 866             deferredLintHandler.setPos(prevLintPos);
 867         }
 868     }
 869 
 870     /** Attribute type reference in an `extends' or `implements' clause.
 871      *  Supertypes of anonymous inner classes are usually already attributed.
 872      *
 873      *  @param tree              The tree making up the type reference.
 874      *  @param env               The environment current at the reference.
 875      *  @param classExpected     true if only a class is expected here.
 876      *  @param interfaceExpected true if only an interface is expected here.
 877      */
 878     Type attribBase(JCTree tree,
 879                     Env<AttrContext> env,
 880                     boolean classExpected,
 881                     boolean interfaceExpected,
 882                     boolean checkExtensible) {
 883         Type t = tree.type != null ?
 884             tree.type :
 885             attribType(tree, env);
 886         try {
 887             return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 888         } catch (CompletionFailure ex) {
 889             chk.completionError(tree.pos(), ex);
 890             return t;
 891         }
 892     }
 893     Type checkBase(Type t,
 894                    JCTree tree,
 895                    Env<AttrContext> env,
 896                    boolean classExpected,
 897                    boolean interfaceExpected,
 898                    boolean checkExtensible) {
 899         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 900                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 901         if (t.tsym.isAnonymous()) {
 902             log.error(pos, Errors.CantInheritFromAnon);
 903             return types.createErrorType(t);
 904         }
 905         if (t.isErroneous())
 906             return t;
 907         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 908             // check that type variable is already visible
 909             if (t.getUpperBound() == null) {
 910                 log.error(pos, Errors.IllegalForwardRef);
 911                 return types.createErrorType(t);
 912             }
 913         } else {
 914             t = chk.checkClassType(pos, t, checkExtensible);
 915         }
 916         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 917             log.error(pos, Errors.IntfExpectedHere);
 918             // return errType is necessary since otherwise there might
 919             // be undetected cycles which cause attribution to loop
 920             return types.createErrorType(t);
 921         } else if (checkExtensible &&
 922                    classExpected &&
 923                    (t.tsym.flags() & INTERFACE) != 0) {
 924             log.error(pos, Errors.NoIntfExpectedHere);
 925             return types.createErrorType(t);
 926         }
 927         if (checkExtensible &&
 928             ((t.tsym.flags() & FINAL) != 0)) {
 929             log.error(pos,
 930                       Errors.CantInheritFromFinal(t.tsym));
 931         }
 932         chk.checkNonCyclic(pos, t);
 933         return t;
 934     }
 935 
 936     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 937         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 938         id.type = env.info.scope.owner.enclClass().type;
 939         id.sym = env.info.scope.owner.enclClass();
 940         return id.type;
 941     }
 942 
 943     public void visitClassDef(JCClassDecl tree) {
 944         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 945                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 946                         argumentAttr.withLocalCacheContext() : null);
 947         try {
 948             // Local and anonymous classes have not been entered yet, so we need to
 949             // do it now.
 950             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 951                 enter.classEnter(tree, env);
 952             } else {
 953                 // If this class declaration is part of a class level annotation,
 954                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 955                 // order to simplify later steps and allow for sensible error
 956                 // messages.
 957                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 958                     enter.classEnter(tree, env);
 959             }
 960 
 961             ClassSymbol c = tree.sym;
 962             if (c == null) {
 963                 // exit in case something drastic went wrong during enter.
 964                 result = null;
 965             } else {
 966                 // make sure class has been completed:
 967                 c.complete();
 968 
 969                 // If this class appears as an anonymous class
 970                 // in a superclass constructor call
 971                 // disable implicit outer instance from being passed.
 972                 // (This would be an illegal access to "this before super").
 973                 if (env.info.isSelfCall &&
 974                         env.tree.hasTag(NEWCLASS)) {
 975                     c.flags_field |= NOOUTERTHIS;
 976                 }
 977                 attribClass(tree.pos(), c);
 978                 result = tree.type = c.type;
 979             }
 980         } finally {
 981             localCacheContext.ifPresent(LocalCacheContext::leave);
 982         }
 983     }
 984 
 985     public void visitMethodDef(JCMethodDecl tree) {
 986         MethodSymbol m = tree.sym;
 987         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
 988 
 989         Lint lint = env.info.lint.augment(m);
 990         Lint prevLint = chk.setLint(lint);
 991         MethodSymbol prevMethod = chk.setMethod(m);
 992         try {
 993             deferredLintHandler.flush(tree.pos());
 994             chk.checkDeprecatedAnnotation(tree.pos(), m);
 995 
 996 
 997             // Create a new environment with local scope
 998             // for attributing the method.
 999             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
1000             localEnv.info.lint = lint;
1001 
1002             attribStats(tree.typarams, localEnv);
1003 
1004             // If we override any other methods, check that we do so properly.
1005             // JLS ???
1006             if (m.isStatic()) {
1007                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1008             } else {
1009                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1010             }
1011             chk.checkOverride(env, tree, m);
1012 
1013             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1014                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1015             }
1016 
1017             // Enter all type parameters into the local method scope.
1018             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1019                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1020 
1021             ClassSymbol owner = env.enclClass.sym;
1022             if ((owner.flags() & ANNOTATION) != 0 &&
1023                     (tree.params.nonEmpty() ||
1024                     tree.recvparam != null))
1025                 log.error(tree.params.nonEmpty() ?
1026                         tree.params.head.pos() :
1027                         tree.recvparam.pos(),
1028                         Errors.IntfAnnotationMembersCantHaveParams);
1029 
1030             // Attribute all value parameters.
1031             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1032                 attribStat(l.head, localEnv);
1033             }
1034 
1035             chk.checkVarargsMethodDecl(localEnv, tree);
1036 
1037             // Check that type parameters are well-formed.
1038             chk.validate(tree.typarams, localEnv);
1039 
1040             // Check that result type is well-formed.
1041             if (tree.restype != null && !tree.restype.type.hasTag(VOID))
1042                 chk.validate(tree.restype, localEnv);
1043 
1044             // Check that receiver type is well-formed.
1045             if (tree.recvparam != null) {
1046                 // Use a new environment to check the receiver parameter.
1047                 // Otherwise I get "might not have been initialized" errors.
1048                 // Is there a better way?
1049                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1050                 attribType(tree.recvparam, newEnv);
1051                 chk.validate(tree.recvparam, newEnv);
1052             }
1053 
1054             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1055                 // lets find if this method is an accessor
1056                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1057                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1058                 if (recordComponent.isPresent()) {
1059                     // the method is a user defined accessor lets check that everything is fine
1060                     if (!tree.sym.isPublic()) {
1061                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1062                     }
1063                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1064                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1065                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1066                     }
1067                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1068                         log.error(tree,
1069                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1070                     }
1071                     if (!tree.typarams.isEmpty()) {
1072                         log.error(tree,
1073                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1074                     }
1075                     if (tree.sym.isStatic()) {
1076                         log.error(tree,
1077                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1078                     }
1079                 }
1080 
1081                 if (names.isInitOrVNew(tree.name)) {
1082                     // if this a constructor other than the canonical one
1083                     if ((tree.sym.flags_field & RECORD) == 0) {
1084                         JCMethodInvocation app = TreeInfo.firstConstructorCall(tree);
1085                         if (app == null ||
1086                                 TreeInfo.name(app.meth) != names._this ||
1087                                 !checkFirstConstructorStat(app, tree, false)) {
1088                             log.error(tree, Errors.FirstStatementMustBeCallToAnotherConstructor(env.enclClass.sym));
1089                         }
1090                     } else {
1091                         // but if it is the canonical:
1092 
1093                         /* if user generated, then it shouldn't:
1094                          *     - have an accessibility stricter than that of the record type
1095                          *     - explicitly invoke any other constructor
1096                          */
1097                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1098                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1099                                 log.error(tree,
1100                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1101                                             Errors.InvalidCanonicalConstructorInRecord(
1102                                                 Fragments.Canonical,
1103                                                 env.enclClass.sym.name,
1104                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1105                                             ) :
1106                                             Errors.InvalidCanonicalConstructorInRecord(
1107                                                     Fragments.Canonical,
1108                                                     env.enclClass.sym.name,
1109                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1110                                             )
1111                                 );
1112                             }
1113 
1114                             JCMethodInvocation app = TreeInfo.firstConstructorCall(tree);
1115                             if (app != null &&
1116                                     (TreeInfo.name(app.meth) == names._this ||
1117                                             TreeInfo.name(app.meth) == names._super) &&
1118                                     checkFirstConstructorStat(app, tree, false)) {
1119                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1120                                         Fragments.Canonical, env.enclClass.sym.name,
1121                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1122                             }
1123                         }
1124 
1125                         // also we want to check that no type variables have been defined
1126                         if (!tree.typarams.isEmpty()) {
1127                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1128                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1129                         }
1130 
1131                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1132                          * record components
1133                          */
1134                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1135                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1136                         for (JCVariableDecl param: tree.params) {
1137                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1138                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1139                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1140                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1141                                         Fragments.Canonical, env.enclClass.sym.name,
1142                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1143                             }
1144                             recordComponents = recordComponents.tail;
1145                             recordFieldTypes = recordFieldTypes.tail;
1146                         }
1147                     }
1148                 }
1149             }
1150 
1151             // annotation method checks
1152             if ((owner.flags() & ANNOTATION) != 0) {
1153                 // annotation method cannot have throws clause
1154                 if (tree.thrown.nonEmpty()) {
1155                     log.error(tree.thrown.head.pos(),
1156                               Errors.ThrowsNotAllowedInIntfAnnotation);
1157                 }
1158                 // annotation method cannot declare type-parameters
1159                 if (tree.typarams.nonEmpty()) {
1160                     log.error(tree.typarams.head.pos(),
1161                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1162                 }
1163                 // validate annotation method's return type (could be an annotation type)
1164                 chk.validateAnnotationType(tree.restype);
1165                 // ensure that annotation method does not clash with members of Object/Annotation
1166                 chk.validateAnnotationMethod(tree.pos(), m);
1167             }
1168 
1169             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1170                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1171 
1172             if (tree.body == null) {
1173                 // Empty bodies are only allowed for
1174                 // abstract, native, or interface methods, or for methods
1175                 // in a retrofit signature class.
1176                 if (tree.defaultValue != null) {
1177                     if ((owner.flags() & ANNOTATION) == 0)
1178                         log.error(tree.pos(),
1179                                   Errors.DefaultAllowedInIntfAnnotationMember);
1180                 }
1181                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1182                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract);
1183             } else {
1184                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1185                     if ((owner.flags() & INTERFACE) != 0) {
1186                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1187                     } else {
1188                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1189                     }
1190                 } else if ((tree.mods.flags & NATIVE) != 0) {
1191                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1192                 }
1193                 // Add an implicit super() call unless an explicit call to
1194                 // super(...) or this(...) is given
1195                 // or we are compiling class java.lang.Object.
1196                 if (names.isInitOrVNew(tree.name) && owner.type != syms.objectType) {
1197                     JCBlock body = tree.body;
1198                     if (body.stats.isEmpty() ||
1199                             TreeInfo.getConstructorInvocationName(body.stats, names, true) == names.empty) {
1200                         JCStatement supCall = make.at(body.pos).Exec(make.Apply(List.nil(),
1201                                 make.Ident(names._super), make.Idents(List.nil())));
1202                         body.stats = body.stats.prepend(supCall);
1203                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1204                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1205                             TreeInfo.isSuperCall(body.stats.head)) {
1206                         // enum constructors are not allowed to call super
1207                         // directly, so make sure there aren't any super calls
1208                         // in enum constructors, except in the compiler
1209                         // generated one.
1210                         log.error(tree.body.stats.head.pos(),
1211                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1212                     } else if ((env.enclClass.sym.flags() & VALUE_CLASS) != 0 &&
1213                         (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1214                         TreeInfo.isSuperCall(body.stats.head)) {
1215                         // value constructors are not allowed to call super directly,
1216                         // but tolerate compiler generated ones, these are ignored during code generation
1217                         log.error(tree.body.stats.head.pos(), Errors.CallToSuperNotAllowedInValueCtor);
1218                     }
1219                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1220                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1221                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1222                         if (!initParamNames.equals(recordComponentNames)) {
1223                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1224                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1225                         }
1226                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1227                             log.error(tree,
1228                                     Errors.InvalidCanonicalConstructorInRecord(
1229                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1230                                             env.enclClass.sym.name,
1231                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1232                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1233                         }
1234                     }
1235                 }
1236 
1237                 // Attribute all type annotations in the body
1238                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m, null);
1239                 annotate.flush();
1240 
1241                 // Attribute method body.
1242                 attribStat(tree.body, localEnv);
1243             }
1244 
1245             localEnv.info.scope.leave();
1246             result = tree.type = m.type;
1247         } finally {
1248             chk.setLint(prevLint);
1249             chk.setMethod(prevMethod);
1250         }
1251     }
1252 
1253     public void visitVarDef(JCVariableDecl tree) {
1254         // Local variables have not been entered yet, so we need to do it now:
1255         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1256             if (tree.sym != null) {
1257                 // parameters have already been entered
1258                 env.info.scope.enter(tree.sym);
1259             } else {
1260                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
1261                     if (tree.init == null) {
1262                         //cannot use 'var' without initializer
1263                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1264                         tree.vartype = make.Erroneous();
1265                     } else {
1266                         Fragment msg = canInferLocalVarType(tree);
1267                         if (msg != null) {
1268                             //cannot use 'var' with initializer which require an explicit target
1269                             //(e.g. lambda, method reference, array initializer).
1270                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1271                             tree.vartype = make.Erroneous();
1272                         }
1273                     }
1274                 }
1275                 try {
1276                     annotate.blockAnnotations();
1277                     memberEnter.memberEnter(tree, env);
1278                 } finally {
1279                     annotate.unblockAnnotations();
1280                 }
1281             }
1282         } else {
1283             if (tree.init != null) {
1284                 // Field initializer expression need to be entered.
1285                 annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym, tree.pos());
1286                 annotate.flush();
1287             }
1288         }
1289 
1290         VarSymbol v = tree.sym;
1291         Lint lint = env.info.lint.augment(v);
1292         Lint prevLint = chk.setLint(lint);
1293 
1294         // Check that the variable's declared type is well-formed.
1295         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1296                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1297                 (tree.sym.flags() & PARAMETER) != 0;
1298         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1299 
1300         try {
1301             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1302             deferredLintHandler.flush(tree.pos());
1303             chk.checkDeprecatedAnnotation(tree.pos(), v);
1304 
1305             /* Don't want constant propagation/folding for instance fields of primitive classes,
1306                as these can undergo updates via copy on write.
1307             */
1308             if (tree.init != null) {
1309                 if ((v.flags_field & FINAL) == 0 || ((v.flags_field & STATIC) == 0 && v.owner.isValueClass()) ||
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) localEnv.info.staticLevel++;
1435             // Attribute all type annotations in the block
1436             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner, null);
1437             annotate.flush();
1438             attribStats(tree.stats, localEnv);
1439 
1440             {
1441                 // Store init and clinit type annotations with the ClassSymbol
1442                 // to allow output in Gen.normalizeDefs.
1443                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1444                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1445                 if ((tree.flags & STATIC) != 0) {
1446                     cs.appendClassInitTypeAttributes(tas);
1447                 } else {
1448                     cs.appendInitTypeAttributes(tas);
1449                 }
1450             }
1451         } else {
1452             // Create a new local environment with a local scope.
1453             Env<AttrContext> localEnv =
1454                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1455             try {
1456                 attribStats(tree.stats, localEnv);
1457             } finally {
1458                 localEnv.info.scope.leave();
1459             }
1460         }
1461         result = null;
1462     }
1463 
1464     public void visitDoLoop(JCDoWhileLoop tree) {
1465         attribStat(tree.body, env.dup(tree));
1466         attribExpr(tree.cond, env, syms.booleanType);
1467         if (!breaksOutOf(tree, tree.body)) {
1468             //include condition's body when false after the while, if cannot get out of the loop
1469             MatchBindings condBindings = matchBindings;
1470             condBindings.bindingsWhenFalse.forEach(env.info.scope::enter);
1471             condBindings.bindingsWhenFalse.forEach(BindingSymbol::preserveBinding);
1472         }
1473         result = null;
1474     }
1475 
1476     public void visitWhileLoop(JCWhileLoop tree) {
1477         attribExpr(tree.cond, env, syms.booleanType);
1478         MatchBindings condBindings = matchBindings;
1479         // include condition's bindings when true in the body:
1480         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1481         try {
1482             attribStat(tree.body, whileEnv.dup(tree));
1483         } finally {
1484             whileEnv.info.scope.leave();
1485         }
1486         if (!breaksOutOf(tree, tree.body)) {
1487             //include condition's bindings when false after the while, if cannot get out of the loop
1488             condBindings.bindingsWhenFalse.forEach(env.info.scope::enter);
1489             condBindings.bindingsWhenFalse.forEach(BindingSymbol::preserveBinding);
1490         }
1491         result = null;
1492     }
1493 
1494     private boolean breaksOutOf(JCTree loop, JCTree body) {
1495         preFlow(body);
1496         return flow.breaksOutOf(env, loop, body, make);
1497     }
1498 
1499     public void visitForLoop(JCForLoop tree) {
1500         Env<AttrContext> loopEnv =
1501             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1502         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1503         try {
1504             attribStats(tree.init, loopEnv);
1505             if (tree.cond != null) {
1506                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1507                 // include condition's bindings when true in the body and step:
1508                 condBindings = matchBindings;
1509             }
1510             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1511             try {
1512                 bodyEnv.tree = tree; // before, we were not in loop!
1513                 attribStats(tree.step, bodyEnv);
1514                 attribStat(tree.body, bodyEnv);
1515             } finally {
1516                 bodyEnv.info.scope.leave();
1517             }
1518             result = null;
1519         }
1520         finally {
1521             loopEnv.info.scope.leave();
1522         }
1523         if (!breaksOutOf(tree, tree.body)) {
1524             //include condition's body when false after the while, if cannot get out of the loop
1525             condBindings.bindingsWhenFalse.forEach(env.info.scope::enter);
1526             condBindings.bindingsWhenFalse.forEach(BindingSymbol::preserveBinding);
1527         }
1528     }
1529 
1530     public void visitForeachLoop(JCEnhancedForLoop tree) {
1531         Env<AttrContext> loopEnv =
1532             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1533 
1534         try {
1535             //the Formal Parameter of a for-each loop is not in the scope when
1536             //attributing the for-each expression; we mimic this by attributing
1537             //the for-each expression first (against original scope).
1538             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1539             chk.checkNonVoid(tree.pos(), exprType);
1540             tree.elementType = types.elemtype(exprType); // perhaps expr is an array?
1541             if (tree.elementType == null) {
1542                 // or perhaps expr implements Iterable<T>?
1543                 Type base = types.asSuper(exprType.referenceProjectionOrSelf(), syms.iterableType.tsym);
1544                 if (base == null) {
1545                     log.error(tree.expr.pos(),
1546                               Errors.ForeachNotApplicableToType(exprType,
1547                                                                 Fragments.TypeReqArrayOrIterable));
1548                     tree.elementType = types.createErrorType(exprType);
1549                 } else {
1550                     List<Type> iterableParams = base.allparams();
1551                     tree.elementType = iterableParams.isEmpty()
1552                         ? syms.objectType
1553                         : types.wildUpperBound(iterableParams.head);
1554 
1555                     // Check the return type of the method iterator().
1556                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1557                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1558                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1559                     if (types.asSuper(iterSymbol.type.getReturnType().referenceProjectionOrSelf(), syms.iteratorType.tsym) == null) {
1560                         log.error(tree.pos(),
1561                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1562                     }
1563                 }
1564             }
1565             if (tree.varOrRecordPattern instanceof JCVariableDecl jcVariableDecl) {
1566                 if (jcVariableDecl.isImplicitlyTyped()) {
1567                     Type inferredType = chk.checkLocalVarType(jcVariableDecl, tree.elementType, jcVariableDecl.name);
1568                     setSyntheticVariableType(jcVariableDecl, inferredType);
1569                 }
1570                 attribStat(jcVariableDecl, loopEnv);
1571                 chk.checkType(tree.expr.pos(), tree.elementType, jcVariableDecl.sym.type);
1572 
1573                 loopEnv.tree = tree; // before, we were not in loop!
1574                 attribStat(tree.body, loopEnv);
1575             } else {
1576                 Assert.check(tree.getDeclarationKind() == EnhancedForLoopTree.DeclarationKind.PATTERN);
1577                 JCRecordPattern jcRecordPattern = (JCRecordPattern) tree.varOrRecordPattern;
1578 
1579                 attribExpr(jcRecordPattern, loopEnv, tree.elementType);
1580 
1581                 // for(<pattern> x : xs) { y }
1582                 // we include x's bindings when true in y
1583                 // we don't do anything with x's bindings when false
1584 
1585                 MatchBindings forWithRecordPatternBindings = matchBindings;
1586                 Env<AttrContext> recordPatternEnv = bindingEnv(loopEnv, forWithRecordPatternBindings.bindingsWhenTrue);
1587 
1588                 Type clazztype = jcRecordPattern.type;
1589 
1590                 checkCastablePattern(tree.expr.pos(), tree.elementType, clazztype);
1591 
1592                 recordPatternEnv.tree = tree; // before, we were not in loop!
1593                 try {
1594                     attribStat(tree.body, recordPatternEnv);
1595                 } finally {
1596                     recordPatternEnv.info.scope.leave();
1597                 }
1598             }
1599             result = null;
1600         }
1601         finally {
1602             loopEnv.info.scope.leave();
1603         }
1604     }
1605 
1606     public void visitLabelled(JCLabeledStatement tree) {
1607         // Check that label is not used in an enclosing statement
1608         Env<AttrContext> env1 = env;
1609         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1610             if (env1.tree.hasTag(LABELLED) &&
1611                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1612                 log.error(tree.pos(),
1613                           Errors.LabelAlreadyInUse(tree.label));
1614                 break;
1615             }
1616             env1 = env1.next;
1617         }
1618 
1619         attribStat(tree.body, env.dup(tree));
1620         result = null;
1621     }
1622 
1623     public void visitSwitch(JCSwitch tree) {
1624         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1625             attribStats(c.stats, caseEnv);
1626         });
1627         result = null;
1628     }
1629 
1630     public void visitSwitchExpression(JCSwitchExpression tree) {
1631         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
1632                 PolyKind.STANDALONE : PolyKind.POLY;
1633 
1634         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
1635             //this means we are returning a poly conditional from void-compatible lambda expression
1636             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
1637             result = tree.type = types.createErrorType(resultInfo.pt);
1638             return;
1639         }
1640 
1641         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
1642                 unknownExprInfo :
1643                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
1644 
1645         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
1646         ListBuffer<Type> caseTypes = new ListBuffer<>();
1647 
1648         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1649             caseEnv.info.yieldResult = condInfo;
1650             attribStats(c.stats, caseEnv);
1651             new TreeScanner() {
1652                 @Override
1653                 public void visitYield(JCYield brk) {
1654                     if (brk.target == tree) {
1655                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
1656                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
1657                     }
1658                     super.visitYield(brk);
1659                 }
1660 
1661                 @Override public void visitClassDef(JCClassDecl tree) {}
1662                 @Override public void visitLambda(JCLambda tree) {}
1663             }.scan(c.stats);
1664         });
1665 
1666         if (tree.cases.isEmpty()) {
1667             log.error(tree.pos(),
1668                       Errors.SwitchExpressionEmpty);
1669         } else if (caseTypes.isEmpty()) {
1670             log.error(tree.pos(),
1671                       Errors.SwitchExpressionNoResultExpressions);
1672         }
1673 
1674         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
1675 
1676         result = tree.type = check(tree, owntype, KindSelector.VAL, resultInfo);
1677     }
1678     //where:
1679         CheckContext switchExpressionContext(CheckContext checkContext) {
1680             return new Check.NestedCheckContext(checkContext) {
1681                 //this will use enclosing check context to check compatibility of
1682                 //subexpression against target type; if we are in a method check context,
1683                 //depending on whether boxing is allowed, we could have incompatibilities
1684                 @Override
1685                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1686                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
1687                 }
1688             };
1689         }
1690 
1691     private void handleSwitch(JCTree switchTree,
1692                               JCExpression selector,
1693                               List<JCCase> cases,
1694                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
1695         Type seltype = attribExpr(selector, env);
1696 
1697         Env<AttrContext> switchEnv =
1698             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
1699 
1700         try {
1701             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
1702             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
1703             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
1704             boolean patternSwitch;
1705             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
1706                 !types.isAssignable(seltype, syms.intType)) {
1707                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
1708                 patternSwitch = true;
1709             } else {
1710                 patternSwitch = cases.stream()
1711                                      .flatMap(c -> c.labels.stream())
1712                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
1713                                                     TreeInfo.isNullCaseLabel(l));
1714             }
1715 
1716             // Attribute all cases and
1717             // check that there are no duplicate case labels or default clauses.
1718             Set<Object> constants = new HashSet<>(); // The set of case constants.
1719             boolean hasDefault = false;           // Is there a default label?
1720             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
1721             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
1722             boolean hasNullPattern = false;       // Is there a null pattern?
1723             CaseTree.CaseKind caseKind = null;
1724             boolean wasError = false;
1725             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
1726                 JCCase c = l.head;
1727                 if (caseKind == null) {
1728                     caseKind = c.caseKind;
1729                 } else if (caseKind != c.caseKind && !wasError) {
1730                     log.error(c.pos(),
1731                               Errors.SwitchMixingCaseTypes);
1732                     wasError = true;
1733                 }
1734                 MatchBindings currentBindings = null;
1735                 boolean wasUnconditionalPattern = hasUnconditionalPattern;
1736                 for (JCCaseLabel label : c.labels) {
1737                     if (label instanceof JCConstantCaseLabel constLabel) {
1738                         JCExpression expr = constLabel.expr;
1739                         if (TreeInfo.isNull(expr)) {
1740                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
1741                             if (hasNullPattern) {
1742                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1743                             }
1744                             hasNullPattern = true;
1745                             attribExpr(expr, switchEnv, seltype);
1746                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
1747                         } else if (enumSwitch) {
1748                             Symbol sym = enumConstant(expr, seltype);
1749                             if (sym == null) {
1750                                 log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
1751                             } else if (!constants.add(sym)) {
1752                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1753                             }
1754                         } else if (errorEnumSwitch) {
1755                             //error recovery: the selector is erroneous, and all the case labels
1756                             //are identifiers. This could be an enum switch - don't report resolve
1757                             //error for the case label:
1758                             var prevResolveHelper = rs.basicLogResolveHelper;
1759                             try {
1760                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
1761                                 attribExpr(expr, switchEnv, seltype);
1762                             } finally {
1763                                 rs.basicLogResolveHelper = prevResolveHelper;
1764                             }
1765                         } else {
1766                             ResultInfo valTypInfo = new ResultInfo(KindSelector.VAL_TYP,
1767                                                                    !seltype.hasTag(ERROR) ? seltype
1768                                                                                           : Type.noType);
1769                             Type pattype = attribTree(expr, switchEnv, valTypInfo);
1770                             if (!pattype.hasTag(ERROR)) {
1771                                 if (pattype.constValue() == null) {
1772                                     Symbol s = TreeInfo.symbol(expr);
1773                                     if (s != null && s.kind == TYP && allowPatternSwitch) {
1774                                         log.error(expr.pos(),
1775                                                   Errors.PatternExpected);
1776                                     } else {
1777                                         log.error(expr.pos(),
1778                                                   (stringSwitch ? Errors.StringConstReq : Errors.ConstExprReq));
1779                                     }
1780                                 } else if (!stringSwitch && !types.isAssignable(seltype, syms.intType)) {
1781                                     log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
1782                                 } else if (!constants.add(pattype.constValue())) {
1783                                     log.error(c.pos(), Errors.DuplicateCaseLabel);
1784                                 }
1785                             }
1786                         }
1787                     } else if (label instanceof JCDefaultCaseLabel def) {
1788                         if (hasDefault) {
1789                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
1790                         } else if (hasUnconditionalPattern) {
1791                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
1792                         }
1793                         hasDefault = true;
1794                         matchBindings = MatchBindingsComputer.EMPTY;
1795                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
1796                         //pattern
1797                         JCPattern pat = patternlabel.pat;
1798                         attribExpr(pat, switchEnv, seltype);
1799                         Type primaryType = TreeInfo.primaryPatternType(pat);
1800                         if (!primaryType.hasTag(TYPEVAR)) {
1801                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
1802                         }
1803                         checkCastablePattern(pat.pos(), seltype, primaryType);
1804                         Type patternType = types.erasure(primaryType);
1805                         JCExpression guard = patternlabel.guard;
1806                         if (guard != null) {
1807                             MatchBindings afterPattern = matchBindings;
1808                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
1809                             try {
1810                                 attribExpr(guard, bodyEnv, syms.booleanType);
1811                             } finally {
1812                                 bodyEnv.info.scope.leave();
1813                             }
1814                             matchBindings = matchBindingsComputer.caseGuard(c, afterPattern, matchBindings);
1815 
1816                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
1817                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
1818                             }
1819                         }
1820                         boolean unguarded = TreeInfo.unguardedCaseLabel(label) && !pat.hasTag(RECORDPATTERN);
1821                         boolean unconditional =
1822                                 unguarded &&
1823                                 !patternType.isErroneous() &&
1824                                 types.isSubtype(types.boxedTypeOrType(types.erasure(seltype)),
1825                                                 patternType);
1826                         if (unconditional) {
1827                             if (hasUnconditionalPattern) {
1828                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
1829                             } else if (hasDefault) {
1830                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
1831                             }
1832                             hasUnconditionalPattern = true;
1833                         }
1834                         lastPatternErroneous = patternType.isErroneous();
1835                     } else {
1836                         Assert.error();
1837                     }
1838                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
1839                 }
1840 
1841                 Env<AttrContext> caseEnv =
1842                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
1843                 try {
1844                     attribCase.accept(c, caseEnv);
1845                 } finally {
1846                     caseEnv.info.scope.leave();
1847                 }
1848                 addVars(c.stats, switchEnv.info.scope);
1849 
1850                 preFlow(c);
1851                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
1852             }
1853             if (patternSwitch) {
1854                 chk.checkSwitchCaseStructure(cases);
1855                 chk.checkSwitchCaseLabelDominated(cases);
1856             }
1857             if (switchTree.hasTag(SWITCH)) {
1858                 ((JCSwitch) switchTree).hasUnconditionalPattern =
1859                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1860                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
1861             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
1862                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
1863                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1864                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
1865             } else {
1866                 Assert.error(switchTree.getTag().name());
1867             }
1868         } finally {
1869             switchEnv.info.scope.leave();
1870         }
1871     }
1872     // where
1873         /** Add any variables defined in stats to the switch scope. */
1874         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
1875             for (;stats.nonEmpty(); stats = stats.tail) {
1876                 JCTree stat = stats.head;
1877                 if (stat.hasTag(VARDEF))
1878                     switchScope.enter(((JCVariableDecl) stat).sym);
1879             }
1880         }
1881     // where
1882     /** Return the selected enumeration constant symbol, or null. */
1883     private Symbol enumConstant(JCTree tree, Type enumType) {
1884         if (tree.hasTag(IDENT)) {
1885             JCIdent ident = (JCIdent)tree;
1886             Name name = ident.name;
1887             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
1888                 if (sym.kind == VAR) {
1889                     Symbol s = ident.sym = sym;
1890                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1891                     ident.type = s.type;
1892                     return ((s.flags_field & Flags.ENUM) == 0)
1893                         ? null : s;
1894                 }
1895             }
1896         }
1897         return null;
1898     }
1899 
1900     public void visitSynchronized(JCSynchronized tree) {
1901         chk.checkIdentityType(tree.pos(), attribExpr(tree.lock, env));
1902         if (env.info.lint.isEnabled(LintCategory.SYNCHRONIZATION) && isValueBased(tree.lock.type)) {
1903             log.warning(LintCategory.SYNCHRONIZATION, tree.pos(), Warnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
1904         }
1905         attribStat(tree.body, env);
1906         result = null;
1907     }
1908         // where
1909         private boolean isValueBased(Type t) {
1910             return t != null && t.tsym != null && (t.tsym.flags() & VALUE_BASED) != 0;
1911         }
1912 
1913 
1914     public void visitTry(JCTry tree) {
1915         // Create a new local environment with a local
1916         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1917         try {
1918             boolean isTryWithResource = tree.resources.nonEmpty();
1919             // Create a nested environment for attributing the try block if needed
1920             Env<AttrContext> tryEnv = isTryWithResource ?
1921                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1922                 localEnv;
1923             try {
1924                 // Attribute resource declarations
1925                 for (JCTree resource : tree.resources) {
1926                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
1927                         @Override
1928                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
1929                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
1930                         }
1931                     };
1932                     ResultInfo twrResult =
1933                         new ResultInfo(KindSelector.VAR,
1934                                        syms.autoCloseableType,
1935                                        twrContext);
1936                     if (resource.hasTag(VARDEF)) {
1937                         attribStat(resource, tryEnv);
1938                         twrResult.check(resource, resource.type);
1939 
1940                         //check that resource type cannot throw InterruptedException
1941                         checkAutoCloseable(resource.pos(), localEnv, resource.type);
1942 
1943                         VarSymbol var = ((JCVariableDecl) resource).sym;
1944 
1945                         var.flags_field |= Flags.FINAL;
1946                         var.setData(ElementKind.RESOURCE_VARIABLE);
1947                     } else {
1948                         attribTree(resource, tryEnv, twrResult);
1949                     }
1950                 }
1951                 // Attribute body
1952                 attribStat(tree.body, tryEnv);
1953             } finally {
1954                 if (isTryWithResource)
1955                     tryEnv.info.scope.leave();
1956             }
1957 
1958             // Attribute catch clauses
1959             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
1960                 JCCatch c = l.head;
1961                 Env<AttrContext> catchEnv =
1962                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
1963                 try {
1964                     Type ctype = attribStat(c.param, catchEnv);
1965                     if (TreeInfo.isMultiCatch(c)) {
1966                         //multi-catch parameter is implicitly marked as final
1967                         c.param.sym.flags_field |= FINAL | UNION;
1968                     }
1969                     if (c.param.sym.kind == VAR) {
1970                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
1971                     }
1972                     chk.checkType(c.param.vartype.pos(),
1973                                   chk.checkClassType(c.param.vartype.pos(), ctype),
1974                                   syms.throwableType);
1975                     attribStat(c.body, catchEnv);
1976                 } finally {
1977                     catchEnv.info.scope.leave();
1978                 }
1979             }
1980 
1981             // Attribute finalizer
1982             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
1983             result = null;
1984         }
1985         finally {
1986             localEnv.info.scope.leave();
1987         }
1988     }
1989 
1990     void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
1991         if (!resource.isErroneous() &&
1992             types.asSuper(resource.referenceProjectionOrSelf(), syms.autoCloseableType.tsym) != null &&
1993             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
1994             Symbol close = syms.noSymbol;
1995             Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log);
1996             try {
1997                 close = rs.resolveQualifiedMethod(pos,
1998                         env,
1999                         types.skipTypeVars(resource, false),
2000                         names.close,
2001                         List.nil(),
2002                         List.nil());
2003             }
2004             finally {
2005                 log.popDiagnosticHandler(discardHandler);
2006             }
2007             if (close.kind == MTH &&
2008                     close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
2009                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
2010                     env.info.lint.isEnabled(LintCategory.TRY)) {
2011                 log.warning(LintCategory.TRY, pos, Warnings.TryResourceThrowsInterruptedExc(resource));
2012             }
2013         }
2014     }
2015 
2016     public void visitConditional(JCConditional tree) {
2017         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2018         MatchBindings condBindings = matchBindings;
2019 
2020         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2021                 isBooleanOrNumeric(env, tree)) ?
2022                 PolyKind.STANDALONE : PolyKind.POLY;
2023 
2024         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2025             //this means we are returning a poly conditional from void-compatible lambda expression
2026             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2027             result = tree.type = types.createErrorType(resultInfo.pt);
2028             return;
2029         }
2030 
2031         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2032                 unknownExprInfo :
2033                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2034 
2035 
2036         // x ? y : z
2037         // include x's bindings when true in y
2038         // include x's bindings when false in z
2039 
2040         Type truetype;
2041         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2042         try {
2043             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2044         } finally {
2045             trueEnv.info.scope.leave();
2046         }
2047 
2048         MatchBindings trueBindings = matchBindings;
2049 
2050         Type falsetype;
2051         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2052         try {
2053             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2054         } finally {
2055             falseEnv.info.scope.leave();
2056         }
2057 
2058         MatchBindings falseBindings = matchBindings;
2059 
2060         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2061                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2062                          List.of(truetype, falsetype)) : pt();
2063         if (condtype.constValue() != null &&
2064                 truetype.constValue() != null &&
2065                 falsetype.constValue() != null &&
2066                 !owntype.hasTag(NONE)) {
2067             //constant folding
2068             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2069         }
2070         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2071         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2072     }
2073     //where
2074         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2075             switch (tree.getTag()) {
2076                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2077                               ((JCLiteral)tree).typetag == BOOLEAN ||
2078                               ((JCLiteral)tree).typetag == BOT;
2079                 case LAMBDA: case REFERENCE: return false;
2080                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2081                 case CONDEXPR:
2082                     JCConditional condTree = (JCConditional)tree;
2083                     return isBooleanOrNumeric(env, condTree.truepart) &&
2084                             isBooleanOrNumeric(env, condTree.falsepart);
2085                 case APPLY:
2086                     JCMethodInvocation speculativeMethodTree =
2087                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2088                                     tree, env, unknownExprInfo,
2089                                     argumentAttr.withLocalCacheContext());
2090                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2091                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2092                             env.enclClass.type :
2093                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2094                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2095                     return primitiveOrBoxed(owntype);
2096                 case NEWCLASS:
2097                     JCExpression className =
2098                             removeClassParams.translate(((JCNewClass)tree).clazz);
2099                     JCExpression speculativeNewClassTree =
2100                             (JCExpression)deferredAttr.attribSpeculative(
2101                                     className, env, unknownTypeInfo,
2102                                     argumentAttr.withLocalCacheContext());
2103                     return primitiveOrBoxed(speculativeNewClassTree.type);
2104                 default:
2105                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2106                             argumentAttr.withLocalCacheContext()).type;
2107                     return primitiveOrBoxed(speculativeType);
2108             }
2109         }
2110         //where
2111             boolean primitiveOrBoxed(Type t) {
2112                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2113             }
2114 
2115             TreeTranslator removeClassParams = new TreeTranslator() {
2116                 @Override
2117                 public void visitTypeApply(JCTypeApply tree) {
2118                     result = translate(tree.clazz);
2119                 }
2120             };
2121 
2122         CheckContext conditionalContext(CheckContext checkContext) {
2123             return new Check.NestedCheckContext(checkContext) {
2124                 //this will use enclosing check context to check compatibility of
2125                 //subexpression against target type; if we are in a method check context,
2126                 //depending on whether boxing is allowed, we could have incompatibilities
2127                 @Override
2128                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2129                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2130                 }
2131             };
2132         }
2133 
2134         /** Compute the type of a conditional expression, after
2135          *  checking that it exists.  See JLS 15.25. Does not take into
2136          *  account the special case where condition and both arms
2137          *  are constants.
2138          *
2139          *  @param pos      The source position to be used for error
2140          *                  diagnostics.
2141          *  @param thentype The type of the expression's then-part.
2142          *  @param elsetype The type of the expression's else-part.
2143          */
2144         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2145             if (condTypes.isEmpty()) {
2146                 return syms.objectType; //TODO: how to handle?
2147             }
2148             Type first = condTypes.head;
2149             // If same type, that is the result
2150             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2151                 return first.baseType();
2152 
2153             List<Type> unboxedTypes = condTypes.stream()
2154                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2155                                                .collect(List.collector());
2156 
2157             // Otherwise, if both arms can be converted to a numeric
2158             // type, return the least numeric type that fits both arms
2159             // (i.e. return larger of the two, or return int if one
2160             // arm is short, the other is char).
2161             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2162                 // If one arm has an integer subrange type (i.e., byte,
2163                 // short, or char), and the other is an integer constant
2164                 // that fits into the subrange, return the subrange type.
2165                 for (Type type : unboxedTypes) {
2166                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2167                         continue;
2168                     }
2169                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2170                         return type.baseType();
2171                 }
2172 
2173                 for (TypeTag tag : primitiveTags) {
2174                     Type candidate = syms.typeOfTag[tag.ordinal()];
2175                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2176                         return candidate;
2177                     }
2178                 }
2179             }
2180 
2181             // Those were all the cases that could result in a primitive. See if primitive boxing and primitive
2182             // value conversions bring about a convergence.
2183             condTypes = condTypes.stream()
2184                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type
2185                                          : t.isReferenceProjection() ? t.valueProjection() : t)
2186                                  .collect(List.collector());
2187 
2188             for (Type type : condTypes) {
2189                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2190                     return type.baseType();
2191             }
2192 
2193             Iterator<DiagnosticPosition> posIt = positions.iterator();
2194 
2195             condTypes = condTypes.stream()
2196                                  .map(t -> chk.checkNonVoid(posIt.next(), allowPrimitiveClasses && t.isPrimitiveClass() ? t.referenceProjection() : t))
2197                                  .collect(List.collector());
2198 
2199             // both are known to be reference types (or projections).  The result is
2200             // lub(thentype,elsetype). This cannot fail, as it will
2201             // always be possible to infer "Object" if nothing better.
2202             return types.lub(condTypes.stream()
2203                         .map(t -> t.baseType())
2204                         .filter(t -> !t.hasTag(BOT))
2205                         .collect(List.collector()));
2206         }
2207 
2208     static final TypeTag[] primitiveTags = new TypeTag[]{
2209         BYTE,
2210         CHAR,
2211         SHORT,
2212         INT,
2213         LONG,
2214         FLOAT,
2215         DOUBLE,
2216         BOOLEAN,
2217     };
2218 
2219     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2220         return bindingEnv(env, env.tree, bindings);
2221     }
2222 
2223     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2224         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2225         bindings.forEach(env1.info.scope::enter);
2226         return env1;
2227     }
2228 
2229     public void visitIf(JCIf tree) {
2230         attribExpr(tree.cond, env, syms.booleanType);
2231 
2232         // if (x) { y } [ else z ]
2233         // include x's bindings when true in y
2234         // include x's bindings when false in z
2235 
2236         MatchBindings condBindings = matchBindings;
2237         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2238 
2239         try {
2240             attribStat(tree.thenpart, thenEnv);
2241         } finally {
2242             thenEnv.info.scope.leave();
2243         }
2244 
2245         preFlow(tree.thenpart);
2246         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2247         boolean aliveAfterElse;
2248 
2249         if (tree.elsepart != null) {
2250             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2251             try {
2252                 attribStat(tree.elsepart, elseEnv);
2253             } finally {
2254                 elseEnv.info.scope.leave();
2255             }
2256             preFlow(tree.elsepart);
2257             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2258         } else {
2259             aliveAfterElse = true;
2260         }
2261 
2262         chk.checkEmptyIf(tree);
2263 
2264         List<BindingSymbol> afterIfBindings = List.nil();
2265 
2266         if (aliveAfterThen && !aliveAfterElse) {
2267             afterIfBindings = condBindings.bindingsWhenTrue;
2268         } else if (aliveAfterElse && !aliveAfterThen) {
2269             afterIfBindings = condBindings.bindingsWhenFalse;
2270         }
2271 
2272         afterIfBindings.forEach(env.info.scope::enter);
2273         afterIfBindings.forEach(BindingSymbol::preserveBinding);
2274 
2275         result = null;
2276     }
2277 
2278         void preFlow(JCTree tree) {
2279             attrRecover.doRecovery();
2280             new PostAttrAnalyzer() {
2281                 @Override
2282                 public void scan(JCTree tree) {
2283                     if (tree == null ||
2284                             (tree.type != null &&
2285                             tree.type == Type.stuckType)) {
2286                         //don't touch stuck expressions!
2287                         return;
2288                     }
2289                     super.scan(tree);
2290                 }
2291 
2292                 @Override
2293                 public void visitClassDef(JCClassDecl that) {
2294                     if (that.sym != null) {
2295                         // Method preFlow shouldn't visit class definitions
2296                         // that have not been entered and attributed.
2297                         // See JDK-8254557 and JDK-8203277 for more details.
2298                         super.visitClassDef(that);
2299                     }
2300                 }
2301 
2302                 @Override
2303                 public void visitLambda(JCLambda that) {
2304                     if (that.type != null) {
2305                         // Method preFlow shouldn't visit lambda expressions
2306                         // that have not been entered and attributed.
2307                         // See JDK-8254557 and JDK-8203277 for more details.
2308                         super.visitLambda(that);
2309                     }
2310                 }
2311             }.scan(tree);
2312         }
2313 
2314     public void visitExec(JCExpressionStatement tree) {
2315         //a fresh environment is required for 292 inference to work properly ---
2316         //see Infer.instantiatePolymorphicSignatureInstance()
2317         Env<AttrContext> localEnv = env.dup(tree);
2318         attribExpr(tree.expr, localEnv);
2319         result = null;
2320     }
2321 
2322     public void visitBreak(JCBreak tree) {
2323         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2324         result = null;
2325     }
2326 
2327     public void visitYield(JCYield tree) {
2328         if (env.info.yieldResult != null) {
2329             attribTree(tree.value, env, env.info.yieldResult);
2330             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2331         } else {
2332             log.error(tree.pos(), tree.value.hasTag(PARENS)
2333                     ? Errors.NoSwitchExpressionQualify
2334                     : Errors.NoSwitchExpression);
2335             attribTree(tree.value, env, unknownExprInfo);
2336         }
2337         result = null;
2338     }
2339 
2340     public void visitContinue(JCContinue tree) {
2341         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2342         result = null;
2343     }
2344     //where
2345         /** Return the target of a break, continue or yield statement,
2346          *  if it exists, report an error if not.
2347          *  Note: The target of a labelled break or continue is the
2348          *  (non-labelled) statement tree referred to by the label,
2349          *  not the tree representing the labelled statement itself.
2350          *
2351          *  @param pos     The position to be used for error diagnostics
2352          *  @param tag     The tag of the jump statement. This is either
2353          *                 Tree.BREAK or Tree.CONTINUE.
2354          *  @param label   The label of the jump statement, or null if no
2355          *                 label is given.
2356          *  @param env     The environment current at the jump statement.
2357          */
2358         private JCTree findJumpTarget(DiagnosticPosition pos,
2359                                                    JCTree.Tag tag,
2360                                                    Name label,
2361                                                    Env<AttrContext> env) {
2362             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2363 
2364             if (jumpTarget.snd != null) {
2365                 log.error(pos, jumpTarget.snd);
2366             }
2367 
2368             return jumpTarget.fst;
2369         }
2370         /** Return the target of a break or continue statement, if it exists,
2371          *  report an error if not.
2372          *  Note: The target of a labelled break or continue is the
2373          *  (non-labelled) statement tree referred to by the label,
2374          *  not the tree representing the labelled statement itself.
2375          *
2376          *  @param tag     The tag of the jump statement. This is either
2377          *                 Tree.BREAK or Tree.CONTINUE.
2378          *  @param label   The label of the jump statement, or null if no
2379          *                 label is given.
2380          *  @param env     The environment current at the jump statement.
2381          */
2382         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2383                                                                        Name label,
2384                                                                        Env<AttrContext> env) {
2385             // Search environments outwards from the point of jump.
2386             Env<AttrContext> env1 = env;
2387             JCDiagnostic.Error pendingError = null;
2388             LOOP:
2389             while (env1 != null) {
2390                 switch (env1.tree.getTag()) {
2391                     case LABELLED:
2392                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2393                         if (label == labelled.label) {
2394                             // If jump is a continue, check that target is a loop.
2395                             if (tag == CONTINUE) {
2396                                 if (!labelled.body.hasTag(DOLOOP) &&
2397                                         !labelled.body.hasTag(WHILELOOP) &&
2398                                         !labelled.body.hasTag(FORLOOP) &&
2399                                         !labelled.body.hasTag(FOREACHLOOP)) {
2400                                     pendingError = Errors.NotLoopLabel(label);
2401                                 }
2402                                 // Found labelled statement target, now go inwards
2403                                 // to next non-labelled tree.
2404                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2405                             } else {
2406                                 return Pair.of(labelled, pendingError);
2407                             }
2408                         }
2409                         break;
2410                     case DOLOOP:
2411                     case WHILELOOP:
2412                     case FORLOOP:
2413                     case FOREACHLOOP:
2414                         if (label == null) return Pair.of(env1.tree, pendingError);
2415                         break;
2416                     case SWITCH:
2417                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2418                         break;
2419                     case SWITCH_EXPRESSION:
2420                         if (tag == YIELD) {
2421                             return Pair.of(env1.tree, null);
2422                         } else if (tag == BREAK) {
2423                             pendingError = Errors.BreakOutsideSwitchExpression;
2424                         } else {
2425                             pendingError = Errors.ContinueOutsideSwitchExpression;
2426                         }
2427                         break;
2428                     case LAMBDA:
2429                     case METHODDEF:
2430                     case CLASSDEF:
2431                         break LOOP;
2432                     default:
2433                 }
2434                 env1 = env1.next;
2435             }
2436             if (label != null)
2437                 return Pair.of(null, Errors.UndefLabel(label));
2438             else if (pendingError != null)
2439                 return Pair.of(null, pendingError);
2440             else if (tag == CONTINUE)
2441                 return Pair.of(null, Errors.ContOutsideLoop);
2442             else
2443                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2444         }
2445 
2446     public void visitReturn(JCReturn tree) {
2447         // Check that there is an enclosing method which is
2448         // nested within than the enclosing class.
2449         if (env.info.returnResult == null) {
2450             log.error(tree.pos(), Errors.RetOutsideMeth);
2451         } else if (env.info.yieldResult != null) {
2452             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2453         } else if (!env.info.isLambda &&
2454                 !env.info.isNewClass &&
2455                 env.enclMethod != null &&
2456                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2457             log.error(env.enclMethod,
2458                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2459         } else {
2460             // Attribute return expression, if it exists, and check that
2461             // it conforms to result type of enclosing method.
2462             if (tree.expr != null) {
2463                 if (env.info.returnResult.pt.hasTag(VOID)) {
2464                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2465                               diags.fragment(Fragments.UnexpectedRetVal));
2466                 }
2467                 attribTree(tree.expr, env, env.info.returnResult);
2468             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2469                     !env.info.returnResult.pt.hasTag(NONE)) {
2470                 env.info.returnResult.checkContext.report(tree.pos(),
2471                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2472             }
2473         }
2474         result = null;
2475     }
2476 
2477     public void visitThrow(JCThrow tree) {
2478         Type owntype = attribExpr(tree.expr, env, Type.noType);
2479         chk.checkType(tree, owntype, syms.throwableType);
2480         result = null;
2481     }
2482 
2483     public void visitAssert(JCAssert tree) {
2484         attribExpr(tree.cond, env, syms.booleanType);
2485         if (tree.detail != null) {
2486             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2487         }
2488         result = null;
2489     }
2490 
2491      /** Visitor method for method invocations.
2492      *  NOTE: The method part of an application will have in its type field
2493      *        the return type of the method, not the method's type itself!
2494      */
2495     public void visitApply(JCMethodInvocation tree) {
2496         // The local environment of a method application is
2497         // a new environment nested in the current one.
2498         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2499 
2500         // The types of the actual method arguments.
2501         List<Type> argtypes;
2502 
2503         // The types of the actual method type arguments.
2504         List<Type> typeargtypes = null;
2505 
2506         Name methName = TreeInfo.name(tree.meth);
2507 
2508         boolean isConstructorCall =
2509             methName == names._this || methName == names._super;
2510 
2511         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2512         if (isConstructorCall) {
2513             // We are seeing a ...this(...) or ...super(...) call.
2514             // Check that this is the first statement in a constructor.
2515             checkFirstConstructorStat(tree, env.enclMethod, true);
2516 
2517             // Record the fact
2518             // that this is a constructor call (using isSelfCall).
2519             localEnv.info.isSelfCall = true;
2520 
2521             // Attribute arguments, yielding list of argument types.
2522             localEnv.info.constructorArgs = true;
2523             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2524             localEnv.info.constructorArgs = false;
2525             argtypes = argtypesBuf.toList();
2526             typeargtypes = attribTypes(tree.typeargs, localEnv);
2527 
2528             // Variable `site' points to the class in which the called
2529             // constructor is defined.
2530             Type site = env.enclClass.sym.type;
2531             if (methName == names._super) {
2532                 if (site == syms.objectType) {
2533                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2534                     site = types.createErrorType(syms.objectType);
2535                 } else {
2536                     site = types.supertype(site);
2537                 }
2538             }
2539 
2540             if (site.hasTag(CLASS)) {
2541                 Type encl = site.getEnclosingType();
2542                 while (encl != null && encl.hasTag(TYPEVAR))
2543                     encl = encl.getUpperBound();
2544                 if (encl.hasTag(CLASS)) {
2545                     // we are calling a nested class
2546 
2547                     if (tree.meth.hasTag(SELECT)) {
2548                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2549 
2550                         // We are seeing a prefixed call, of the form
2551                         //     <expr>.super(...).
2552                         // Check that the prefix expression conforms
2553                         // to the outer instance type of the class.
2554                         chk.checkRefType(qualifier.pos(),
2555                                          attribExpr(qualifier, localEnv,
2556                                                     encl));
2557                     } else if (methName == names._super) {
2558                         // qualifier omitted; check for existence
2559                         // of an appropriate implicit qualifier.
2560                         rs.resolveImplicitThis(tree.meth.pos(),
2561                                                localEnv, site, true);
2562                     }
2563                 } else if (tree.meth.hasTag(SELECT)) {
2564                     log.error(tree.meth.pos(),
2565                               Errors.IllegalQualNotIcls(site.tsym));
2566                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2567                 }
2568 
2569                 // if we're calling a java.lang.Enum constructor,
2570                 // prefix the implicit String and int parameters
2571                 if (site.tsym == syms.enumSym)
2572                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
2573 
2574                 // Resolve the called constructor under the assumption
2575                 // that we are referring to a superclass instance of the
2576                 // current instance (JLS ???).
2577                 boolean selectSuperPrev = localEnv.info.selectSuper;
2578                 localEnv.info.selectSuper = true;
2579                 localEnv.info.pendingResolutionPhase = null;
2580                 Symbol sym = rs.resolveConstructor(
2581                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
2582                 localEnv.info.selectSuper = selectSuperPrev;
2583 
2584                 // Set method symbol to resolved constructor...
2585                 TreeInfo.setSymbol(tree.meth, sym);
2586 
2587                 // ...and check that it is legal in the current context.
2588                 // (this will also set the tree's type)
2589                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2590                 checkId(tree.meth, site, sym, localEnv,
2591                         new ResultInfo(kind, mpt));
2592             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
2593                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2594             }
2595             // Otherwise, `site' is an error type and we do nothing
2596             result = tree.type = syms.voidType;
2597         } else {
2598             // Otherwise, we are seeing a regular method call.
2599             // Attribute the arguments, yielding list of argument types, ...
2600             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2601             argtypes = argtypesBuf.toList();
2602             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
2603 
2604             // ... and attribute the method using as a prototype a methodtype
2605             // whose formal argument types is exactly the list of actual
2606             // arguments (this will also set the method symbol).
2607             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2608             localEnv.info.pendingResolutionPhase = null;
2609             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
2610 
2611             // Compute the result type.
2612             Type restype = mtype.getReturnType();
2613             if (restype.hasTag(WILDCARD))
2614                 throw new AssertionError(mtype);
2615 
2616             Type qualifier = (tree.meth.hasTag(SELECT))
2617                     ? ((JCFieldAccess) tree.meth).selected.type
2618                     : env.enclClass.sym.type;
2619             Symbol msym = TreeInfo.symbol(tree.meth);
2620             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
2621 
2622             chk.checkRefTypes(tree.typeargs, typeargtypes);
2623 
2624             // Check that value of resulting type is admissible in the
2625             // current context.  Also, capture the return type
2626             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
2627             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
2628         }
2629         chk.validate(tree.typeargs, localEnv);
2630     }
2631     //where
2632         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
2633             if (msym != null &&
2634                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
2635                     methodName == names.getClass &&
2636                     argtypes.isEmpty()) {
2637                 // as a special case, x.getClass() has type Class<? extends |X|>
2638                 // Special treatment for primitive classes: Given an expression v of type V where
2639                 // V is a primitive class, v.getClass() is typed to be Class<? extends |V.ref|>
2640                 Type wcb = types.erasure(allowPrimitiveClasses && qualifierType.isPrimitiveClass() ?
2641                                          qualifierType.referenceProjection() : qualifierType.baseType());
2642                 return new ClassType(restype.getEnclosingType(),
2643                         List.of(new WildcardType(wcb,
2644                                 BoundKind.EXTENDS,
2645                                 syms.boundClass)),
2646                         restype.tsym,
2647                         restype.getMetadata(),
2648                         restype.getFlavor());
2649             } else if (msym != null &&
2650                     msym.owner == syms.arrayClass &&
2651                     methodName == names.clone &&
2652                     types.isArray(qualifierType)) {
2653                 // as a special case, array.clone() has a result that is
2654                 // the same as static type of the array being cloned
2655                 return qualifierType;
2656             } else {
2657                 return restype;
2658             }
2659         }
2660 
2661         /** Check that given application node appears as first statement
2662          *  in a constructor call.
2663          *  @param tree          The application node
2664          *  @param enclMethod    The enclosing method of the application.
2665          *  @param error         Should an error be issued?
2666          */
2667         boolean checkFirstConstructorStat(JCMethodInvocation tree, JCMethodDecl enclMethod, boolean error) {
2668             if (enclMethod != null && names.isInitOrVNew(enclMethod.name)) {
2669                 JCBlock body = enclMethod.body;
2670                 if (body.stats.head.hasTag(EXEC) &&
2671                     ((JCExpressionStatement) body.stats.head).expr == tree)
2672                     return true;
2673             }
2674             if (error) {
2675                 log.error(tree.pos(),
2676                         Errors.CallMustBeFirstStmtInCtor(TreeInfo.name(tree.meth)));
2677             }
2678             return false;
2679         }
2680 
2681         /** Obtain a method type with given argument types.
2682          */
2683         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
2684             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
2685             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
2686         }
2687 
2688     public void visitNewClass(final JCNewClass tree) {
2689         Type owntype = types.createErrorType(tree.type);
2690 
2691         // The local environment of a class creation is
2692         // a new environment nested in the current one.
2693         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2694 
2695         // The anonymous inner class definition of the new expression,
2696         // if one is defined by it.
2697         JCClassDecl cdef = tree.def;
2698 
2699         // If enclosing class is given, attribute it, and
2700         // complete class name to be fully qualified
2701         JCExpression clazz = tree.clazz; // Class field following new
2702         JCExpression clazzid;            // Identifier in class field
2703         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
2704         annoclazzid = null;
2705 
2706         if (clazz.hasTag(TYPEAPPLY)) {
2707             clazzid = ((JCTypeApply) clazz).clazz;
2708             if (clazzid.hasTag(ANNOTATED_TYPE)) {
2709                 annoclazzid = (JCAnnotatedType) clazzid;
2710                 clazzid = annoclazzid.underlyingType;
2711             }
2712         } else {
2713             if (clazz.hasTag(ANNOTATED_TYPE)) {
2714                 annoclazzid = (JCAnnotatedType) clazz;
2715                 clazzid = annoclazzid.underlyingType;
2716             } else {
2717                 clazzid = clazz;
2718             }
2719         }
2720 
2721         JCExpression clazzid1 = clazzid; // The same in fully qualified form
2722 
2723         if (tree.encl != null) {
2724             // We are seeing a qualified new, of the form
2725             //    <expr>.new C <...> (...) ...
2726             // In this case, we let clazz stand for the name of the
2727             // allocated class C prefixed with the type of the qualifier
2728             // expression, so that we can
2729             // resolve it with standard techniques later. I.e., if
2730             // <expr> has type T, then <expr>.new C <...> (...)
2731             // yields a clazz T.C.
2732             Type encltype = chk.checkRefType(tree.encl.pos(),
2733                                              attribExpr(tree.encl, env));
2734             // TODO 308: in <expr>.new C, do we also want to add the type annotations
2735             // from expr to the combined type, or not? Yes, do this.
2736             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
2737                                                  ((JCIdent) clazzid).name);
2738 
2739             EndPosTable endPosTable = this.env.toplevel.endPositions;
2740             endPosTable.storeEnd(clazzid1, clazzid.getEndPosition(endPosTable));
2741             if (clazz.hasTag(ANNOTATED_TYPE)) {
2742                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
2743                 List<JCAnnotation> annos = annoType.annotations;
2744 
2745                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
2746                     clazzid1 = make.at(tree.pos).
2747                         TypeApply(clazzid1,
2748                                   ((JCTypeApply) clazz).arguments);
2749                 }
2750 
2751                 clazzid1 = make.at(tree.pos).
2752                     AnnotatedType(annos, clazzid1);
2753             } else if (clazz.hasTag(TYPEAPPLY)) {
2754                 clazzid1 = make.at(tree.pos).
2755                     TypeApply(clazzid1,
2756                               ((JCTypeApply) clazz).arguments);
2757             }
2758 
2759             clazz = clazzid1;
2760         }
2761 
2762         // Attribute clazz expression and store
2763         // symbol + type back into the attributed tree.
2764         Type clazztype;
2765 
2766         try {
2767             env.info.isNewClass = true;
2768             clazztype = TreeInfo.isEnumInit(env.tree) ?
2769                 attribIdentAsEnumType(env, (JCIdent)clazz) :
2770                 attribType(clazz, env);
2771         } finally {
2772             env.info.isNewClass = false;
2773         }
2774 
2775         clazztype = chk.checkDiamond(tree, clazztype);
2776         chk.validate(clazz, localEnv);
2777         if (tree.encl != null) {
2778             // We have to work in this case to store
2779             // symbol + type back into the attributed tree.
2780             tree.clazz.type = clazztype;
2781             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
2782             clazzid.type = ((JCIdent) clazzid).sym.type;
2783             if (annoclazzid != null) {
2784                 annoclazzid.type = clazzid.type;
2785             }
2786             if (!clazztype.isErroneous()) {
2787                 if (cdef != null && clazztype.tsym.isInterface()) {
2788                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
2789                 } else if (clazztype.tsym.isStatic()) {
2790                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
2791                 }
2792             }
2793         } else if (!clazztype.tsym.isInterface() &&
2794                    clazztype.getEnclosingType().hasTag(CLASS)) {
2795             // Check for the existence of an apropos outer instance
2796             rs.resolveImplicitThis(tree.pos(), env, clazztype);
2797         }
2798 
2799         // Attribute constructor arguments.
2800         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2801         final KindSelector pkind =
2802             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2803         List<Type> argtypes = argtypesBuf.toList();
2804         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
2805 
2806         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
2807             // Enums may not be instantiated except implicitly
2808             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
2809                 (!env.tree.hasTag(VARDEF) ||
2810                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
2811                  ((JCVariableDecl) env.tree).init != tree))
2812                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
2813 
2814             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
2815                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
2816             boolean skipNonDiamondPath = false;
2817             // Check that it is an instantiation of a class and not a projection type
2818             if (allowPrimitiveClasses) {
2819                 if (clazz.hasTag(SELECT)) {
2820                     JCFieldAccess fieldAccess = (JCFieldAccess) clazz;
2821                     if (fieldAccess.selected.type.isPrimitiveClass() &&
2822                             (fieldAccess.name == names.ref || fieldAccess.name == names.val)) {
2823                         log.error(tree.pos(), Errors.ProjectionCantBeInstantiated);
2824                     }
2825                 }
2826             }
2827             // Check that class is not abstract
2828             if (cdef == null && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
2829                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
2830                 log.error(tree.pos(),
2831                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
2832                 skipNonDiamondPath = true;
2833             } else if (cdef != null && clazztype.tsym.isInterface()) {
2834                 // Check that no constructor arguments are given to
2835                 // anonymous classes implementing an interface
2836                 if (!argtypes.isEmpty())
2837                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
2838 
2839                 if (!typeargtypes.isEmpty())
2840                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
2841 
2842                 // Error recovery: pretend no arguments were supplied.
2843                 argtypes = List.nil();
2844                 typeargtypes = List.nil();
2845                 skipNonDiamondPath = true;
2846             }
2847             if (TreeInfo.isDiamond(tree)) {
2848                 ClassType site = new ClassType(clazztype.getEnclosingType(),
2849                             clazztype.tsym.type.getTypeArguments(),
2850                                                clazztype.tsym,
2851                                                clazztype.getMetadata(),
2852                                                clazztype.getFlavor());
2853 
2854                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
2855                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
2856                 diamondEnv.info.pendingResolutionPhase = null;
2857 
2858                 //if the type of the instance creation expression is a class type
2859                 //apply method resolution inference (JLS 15.12.2.7). The return type
2860                 //of the resolved constructor will be a partially instantiated type
2861                 Symbol constructor = rs.resolveDiamond(tree.pos(),
2862                             diamondEnv,
2863                             site,
2864                             argtypes,
2865                             typeargtypes);
2866                 tree.constructor = constructor.baseSymbol();
2867 
2868                 final TypeSymbol csym = clazztype.tsym;
2869                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
2870                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
2871                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
2872                 constructorType = checkId(tree, site,
2873                         constructor,
2874                         diamondEnv,
2875                         diamondResult);
2876 
2877                 tree.clazz.type = types.createErrorType(clazztype);
2878                 if (!constructorType.isErroneous()) {
2879                     tree.clazz.type = clazz.type = constructorType.getReturnType();
2880                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
2881                 }
2882                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
2883             }
2884 
2885             // Resolve the called constructor under the assumption
2886             // that we are referring to a superclass instance of the
2887             // current instance (JLS ???).
2888             else if (!skipNonDiamondPath) {
2889                 //the following code alters some of the fields in the current
2890                 //AttrContext - hence, the current context must be dup'ed in
2891                 //order to avoid downstream failures
2892                 Env<AttrContext> rsEnv = localEnv.dup(tree);
2893                 rsEnv.info.selectSuper = cdef != null;
2894                 rsEnv.info.pendingResolutionPhase = null;
2895                 tree.constructor = rs.resolveConstructor(
2896                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
2897                 if (cdef == null) { //do not check twice!
2898                     tree.constructorType = checkId(tree,
2899                             clazztype,
2900                             tree.constructor,
2901                             rsEnv,
2902                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
2903                     if (rsEnv.info.lastResolveVarargs())
2904                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
2905                 }
2906             }
2907 
2908             if (cdef != null) {
2909                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
2910                 return;
2911             }
2912 
2913             if (tree.constructor != null && tree.constructor.kind == MTH)
2914                 owntype = clazztype;
2915         }
2916         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2917         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2918         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
2919             //we need to wait for inference to finish and then replace inference vars in the constructor type
2920             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
2921                     instantiatedContext -> {
2922                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2923                     });
2924         }
2925         chk.validate(tree.typeargs, localEnv);
2926     }
2927 
2928         // where
2929         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
2930                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
2931                                                    List<Type> argtypes, List<Type> typeargtypes,
2932                                                    KindSelector pkind) {
2933             // We are seeing an anonymous class instance creation.
2934             // In this case, the class instance creation
2935             // expression
2936             //
2937             //    E.new <typeargs1>C<typargs2>(args) { ... }
2938             //
2939             // is represented internally as
2940             //
2941             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
2942             //
2943             // This expression is then *transformed* as follows:
2944             //
2945             // (1) add an extends or implements clause
2946             // (2) add a constructor.
2947             //
2948             // For instance, if C is a class, and ET is the type of E,
2949             // the expression
2950             //
2951             //    E.new <typeargs1>C<typargs2>(args) { ... }
2952             //
2953             // is translated to (where X is a fresh name and typarams is the
2954             // parameter list of the super constructor):
2955             //
2956             //   new <typeargs1>X(<*nullchk*>E, args) where
2957             //     X extends C<typargs2> {
2958             //       <typarams> X(ET e, args) {
2959             //         e.<typeargs1>super(args)
2960             //       }
2961             //       ...
2962             //     }
2963             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2964             Type enclType = clazztype.getEnclosingType();
2965             if (enclType != null &&
2966                     enclType.hasTag(CLASS) &&
2967                     !chk.checkDenotable((ClassType)enclType)) {
2968                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
2969             }
2970             final boolean isDiamond = TreeInfo.isDiamond(tree);
2971             if (isDiamond
2972                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
2973                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
2974                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
2975                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
2976                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
2977                         instantiatedContext -> {
2978                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2979                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
2980                             ResultInfo prevResult = this.resultInfo;
2981                             try {
2982                                 this.resultInfo = resultInfoForClassDefinition;
2983                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
2984                                         dupLocalEnv, argtypes, typeargtypes, pkind);
2985                             } finally {
2986                                 this.resultInfo = prevResult;
2987                             }
2988                         });
2989             } else {
2990                 if (isDiamond && clazztype.hasTag(CLASS)) {
2991                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
2992                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
2993                         // One or more types inferred in the previous steps is non-denotable.
2994                         Fragment fragment = Diamond(clazztype.tsym);
2995                         log.error(tree.clazz.pos(),
2996                                 Errors.CantApplyDiamond1(
2997                                         fragment,
2998                                         invalidDiamondArgs.size() > 1 ?
2999                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
3000                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
3001                     }
3002                     // For <>(){}, inferred types must also be accessible.
3003                     for (Type t : clazztype.getTypeArguments()) {
3004                         rs.checkAccessibleType(env, t);
3005                     }
3006                     if (allowPrimitiveClasses) {
3007                         chk.checkParameterizationByPrimitiveClass(tree, clazztype);
3008                     }
3009                 }
3010 
3011                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
3012                 // false for isInterface call even when the original type is an interface.
3013                 boolean implementing = clazztype.tsym.isInterface() ||
3014                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
3015                         clazztype.getOriginalType().tsym.isInterface();
3016 
3017                 if (implementing) {
3018                     cdef.implementing = List.of(clazz);
3019                 } else {
3020                     cdef.extending = clazz;
3021                 }
3022 
3023                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3024                     rs.isSerializable(clazztype)) {
3025                     localEnv.info.isSerializable = true;
3026                 }
3027 
3028                 attribStat(cdef, localEnv);
3029 
3030                 List<Type> finalargtypes;
3031                 // If an outer instance is given,
3032                 // prefix it to the constructor arguments
3033                 // and delete it from the new expression
3034                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
3035                     finalargtypes = argtypes.prepend(tree.encl.type);
3036                 } else {
3037                     finalargtypes = argtypes;
3038                 }
3039 
3040                 // Reassign clazztype and recompute constructor. As this necessarily involves
3041                 // another attribution pass for deferred types in the case of <>, replicate
3042                 // them. Original arguments have right decorations already.
3043                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3044                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3045                 }
3046 
3047                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3048                                                     : cdef.sym.type;
3049                 Symbol sym = tree.constructor = rs.resolveConstructor(
3050                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3051                 Assert.check(!sym.kind.isResolutionError());
3052                 tree.constructor = sym;
3053                 tree.constructorType = checkId(tree,
3054                         clazztype,
3055                         tree.constructor,
3056                         localEnv,
3057                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3058             }
3059             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3060                                 clazztype : types.createErrorType(tree.type);
3061             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3062             chk.validate(tree.typeargs, localEnv);
3063         }
3064 
3065         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3066             return new Check.NestedCheckContext(checkContext) {
3067                 @Override
3068                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3069                     enclosingContext.report(clazz.clazz,
3070                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3071                 }
3072             };
3073         }
3074 
3075     /** Make an attributed null check tree.
3076      */
3077     public JCExpression makeNullCheck(JCExpression arg) {
3078         // optimization: new Outer() can never be null; skip null check
3079         if (arg.getTag() == NEWCLASS)
3080             return arg;
3081         // Likewise arg can't be null if it is a primitive class instance.
3082         if (allowPrimitiveClasses && arg.type.isPrimitiveClass())
3083             return arg;
3084         // optimization: X.this is never null; skip null check
3085         Name name = TreeInfo.name(arg);
3086         if (name == names._this || name == names._super) return arg;
3087 
3088         JCTree.Tag optag = NULLCHK;
3089         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3090         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3091         tree.type = arg.type;
3092         return tree;
3093     }
3094 
3095     public void visitNewArray(JCNewArray tree) {
3096         Type owntype = types.createErrorType(tree.type);
3097         Env<AttrContext> localEnv = env.dup(tree);
3098         Type elemtype;
3099         if (tree.elemtype != null) {
3100             elemtype = attribType(tree.elemtype, localEnv);
3101             chk.validate(tree.elemtype, localEnv);
3102             owntype = elemtype;
3103             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3104                 attribExpr(l.head, localEnv, syms.intType);
3105                 owntype = new ArrayType(owntype, syms.arrayClass);
3106             }
3107         } else {
3108             // we are seeing an untyped aggregate { ... }
3109             // this is allowed only if the prototype is an array
3110             if (pt().hasTag(ARRAY)) {
3111                 elemtype = types.elemtype(pt());
3112             } else {
3113                 if (!pt().hasTag(ERROR) &&
3114                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3115                     log.error(tree.pos(),
3116                               Errors.IllegalInitializerForType(pt()));
3117                 }
3118                 elemtype = types.createErrorType(pt());
3119             }
3120         }
3121         if (tree.elems != null) {
3122             attribExprs(tree.elems, localEnv, elemtype);
3123             owntype = new ArrayType(elemtype, syms.arrayClass);
3124         }
3125         if (!types.isReifiable(elemtype))
3126             log.error(tree.pos(), Errors.GenericArrayCreation);
3127         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3128     }
3129 
3130     /*
3131      * A lambda expression can only be attributed when a target-type is available.
3132      * In addition, if the target-type is that of a functional interface whose
3133      * descriptor contains inference variables in argument position the lambda expression
3134      * is 'stuck' (see DeferredAttr).
3135      */
3136     @Override
3137     public void visitLambda(final JCLambda that) {
3138         boolean wrongContext = false;
3139         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3140             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3141                 //lambda only allowed in assignment or method invocation/cast context
3142                 log.error(that.pos(), Errors.UnexpectedLambda);
3143             }
3144             resultInfo = recoveryInfo;
3145             wrongContext = true;
3146         }
3147         //create an environment for attribution of the lambda expression
3148         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3149         boolean needsRecovery =
3150                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3151         try {
3152             if (needsRecovery && rs.isSerializable(pt())) {
3153                 localEnv.info.isSerializable = true;
3154                 localEnv.info.isSerializableLambda = true;
3155             }
3156             List<Type> explicitParamTypes = null;
3157             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3158                 //attribute lambda parameters
3159                 attribStats(that.params, localEnv);
3160                 explicitParamTypes = TreeInfo.types(that.params);
3161             }
3162 
3163             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3164             Type currentTarget = targetInfo.target;
3165             Type lambdaType = targetInfo.descriptor;
3166 
3167             if (currentTarget.isErroneous()) {
3168                 result = that.type = currentTarget;
3169                 return;
3170             }
3171 
3172             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3173 
3174             if (lambdaType.hasTag(FORALL)) {
3175                 //lambda expression target desc cannot be a generic method
3176                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3177                                                                     kindName(currentTarget.tsym),
3178                                                                     currentTarget.tsym);
3179                 resultInfo.checkContext.report(that, diags.fragment(msg));
3180                 result = that.type = types.createErrorType(pt());
3181                 return;
3182             }
3183 
3184             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3185                 //add param type info in the AST
3186                 List<Type> actuals = lambdaType.getParameterTypes();
3187                 List<JCVariableDecl> params = that.params;
3188 
3189                 boolean arityMismatch = false;
3190 
3191                 while (params.nonEmpty()) {
3192                     if (actuals.isEmpty()) {
3193                         //not enough actuals to perform lambda parameter inference
3194                         arityMismatch = true;
3195                     }
3196                     //reset previously set info
3197                     Type argType = arityMismatch ?
3198                             syms.errType :
3199                             actuals.head;
3200                     if (params.head.isImplicitlyTyped()) {
3201                         setSyntheticVariableType(params.head, argType);
3202                     }
3203                     params.head.sym = null;
3204                     actuals = actuals.isEmpty() ?
3205                             actuals :
3206                             actuals.tail;
3207                     params = params.tail;
3208                 }
3209 
3210                 //attribute lambda parameters
3211                 attribStats(that.params, localEnv);
3212 
3213                 if (arityMismatch) {
3214                     resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3215                         result = that.type = types.createErrorType(currentTarget);
3216                         return;
3217                 }
3218             }
3219 
3220             //from this point on, no recovery is needed; if we are in assignment context
3221             //we will be able to attribute the whole lambda body, regardless of errors;
3222             //if we are in a 'check' method context, and the lambda is not compatible
3223             //with the target-type, it will be recovered anyway in Attr.checkId
3224             needsRecovery = false;
3225 
3226             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3227                     lambdaBodyResult(that, lambdaType, resultInfo);
3228 
3229             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3230                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3231             } else {
3232                 JCBlock body = (JCBlock)that.body;
3233                 if (body == breakTree &&
3234                         resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3235                     breakTreeFound(copyEnv(localEnv));
3236                 }
3237                 attribStats(body.stats, localEnv);
3238             }
3239 
3240             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3241 
3242             boolean isSpeculativeRound =
3243                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3244 
3245             preFlow(that);
3246             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3247 
3248             that.type = currentTarget; //avoids recovery at this stage
3249             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
3250 
3251             if (!isSpeculativeRound) {
3252                 //add thrown types as bounds to the thrown types free variables if needed:
3253                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3254                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3255                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3256                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3257                     }
3258                 }
3259 
3260                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3261             }
3262             result = wrongContext ? that.type = types.createErrorType(pt())
3263                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3264         } catch (Types.FunctionDescriptorLookupError ex) {
3265             JCDiagnostic cause = ex.getDiagnostic();
3266             resultInfo.checkContext.report(that, cause);
3267             result = that.type = types.createErrorType(pt());
3268             return;
3269         } catch (CompletionFailure cf) {
3270             chk.completionError(that.pos(), cf);
3271         } catch (Throwable t) {
3272             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3273             //as that would likely cause the same exception again.
3274             needsRecovery = false;
3275             throw t;
3276         } finally {
3277             localEnv.info.scope.leave();
3278             if (needsRecovery) {
3279                 Type prevResult = result;
3280                 try {
3281                     attribTree(that, env, recoveryInfo);
3282                 } finally {
3283                     if (result == Type.recoveryType) {
3284                         result = prevResult;
3285                     }
3286                 }
3287             }
3288         }
3289     }
3290     //where
3291         class TargetInfo {
3292             Type target;
3293             Type descriptor;
3294 
3295             public TargetInfo(Type target, Type descriptor) {
3296                 this.target = target;
3297                 this.descriptor = descriptor;
3298             }
3299         }
3300 
3301         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3302             Type lambdaType;
3303             Type currentTarget = resultInfo.pt;
3304             if (resultInfo.pt != Type.recoveryType) {
3305                 /* We need to adjust the target. If the target is an
3306                  * intersection type, for example: SAM & I1 & I2 ...
3307                  * the target will be updated to SAM
3308                  */
3309                 currentTarget = targetChecker.visit(currentTarget, that);
3310                 if (!currentTarget.isIntersection()) {
3311                     if (explicitParamTypes != null) {
3312                         currentTarget = infer.instantiateFunctionalInterface(that,
3313                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3314                     }
3315                     currentTarget = types.removeWildcards(currentTarget);
3316                     lambdaType = types.findDescriptorType(currentTarget);
3317                 } else {
3318                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3319                     ListBuffer<Type> components = new ListBuffer<>();
3320                     for (Type bound : ict.getExplicitComponents()) {
3321                         if (explicitParamTypes != null) {
3322                             try {
3323                                 bound = infer.instantiateFunctionalInterface(that,
3324                                         bound, explicitParamTypes, resultInfo.checkContext);
3325                             } catch (FunctionDescriptorLookupError t) {
3326                                 // do nothing
3327                             }
3328                         }
3329                         bound = types.removeWildcards(bound);
3330                         components.add(bound);
3331                     }
3332                     currentTarget = types.makeIntersectionType(components.toList());
3333                     currentTarget.tsym.flags_field |= INTERFACE;
3334                     lambdaType = types.findDescriptorType(currentTarget);
3335                 }
3336 
3337             } else {
3338                 currentTarget = Type.recoveryType;
3339                 lambdaType = fallbackDescriptorType(that);
3340             }
3341             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3342                 //lambda expression target desc cannot be a generic method
3343                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3344                                                                     kindName(currentTarget.tsym),
3345                                                                     currentTarget.tsym);
3346                 resultInfo.checkContext.report(that, diags.fragment(msg));
3347                 currentTarget = types.createErrorType(pt());
3348             }
3349             return new TargetInfo(currentTarget, lambdaType);
3350         }
3351 
3352         void preFlow(JCLambda tree) {
3353             attrRecover.doRecovery();
3354             new PostAttrAnalyzer() {
3355                 @Override
3356                 public void scan(JCTree tree) {
3357                     if (tree == null ||
3358                             (tree.type != null &&
3359                             tree.type == Type.stuckType)) {
3360                         //don't touch stuck expressions!
3361                         return;
3362                     }
3363                     super.scan(tree);
3364                 }
3365 
3366                 @Override
3367                 public void visitClassDef(JCClassDecl that) {
3368                     // or class declaration trees!
3369                 }
3370 
3371                 public void visitLambda(JCLambda that) {
3372                     // or lambda expressions!
3373                 }
3374             }.scan(tree.body);
3375         }
3376 
3377         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3378 
3379             @Override
3380             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3381                 return t.isIntersection() ?
3382                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3383             }
3384 
3385             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3386                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3387                 return ict;
3388             }
3389 
3390             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3391                 ListBuffer<Type> targs = new ListBuffer<>();
3392                 ListBuffer<Type> supertypes = new ListBuffer<>();
3393                 for (Type i : ict.interfaces_field) {
3394                     if (i.isParameterized()) {
3395                         targs.appendList(i.tsym.type.allparams());
3396                     }
3397                     supertypes.append(i.tsym.type);
3398                 }
3399                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3400                 notionalIntf.allparams_field = targs.toList();
3401                 notionalIntf.tsym.flags_field |= INTERFACE;
3402                 return notionalIntf.tsym;
3403             }
3404         };
3405 
3406         private Type fallbackDescriptorType(JCExpression tree) {
3407             switch (tree.getTag()) {
3408                 case LAMBDA:
3409                     JCLambda lambda = (JCLambda)tree;
3410                     List<Type> argtypes = List.nil();
3411                     for (JCVariableDecl param : lambda.params) {
3412                         argtypes = param.vartype != null && param.vartype.type != null ?
3413                                 argtypes.append(param.vartype.type) :
3414                                 argtypes.append(syms.errType);
3415                     }
3416                     return new MethodType(argtypes, Type.recoveryType,
3417                             List.of(syms.throwableType), syms.methodClass);
3418                 case REFERENCE:
3419                     return new MethodType(List.nil(), Type.recoveryType,
3420                             List.of(syms.throwableType), syms.methodClass);
3421                 default:
3422                     Assert.error("Cannot get here!");
3423             }
3424             return null;
3425         }
3426 
3427         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3428                 final InferenceContext inferenceContext, final Type... ts) {
3429             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3430         }
3431 
3432         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3433                 final InferenceContext inferenceContext, final List<Type> ts) {
3434             if (inferenceContext.free(ts)) {
3435                 inferenceContext.addFreeTypeListener(ts,
3436                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3437             } else {
3438                 for (Type t : ts) {
3439                     rs.checkAccessibleType(env, t);
3440                 }
3441             }
3442         }
3443 
3444         /**
3445          * Lambda/method reference have a special check context that ensures
3446          * that i.e. a lambda return type is compatible with the expected
3447          * type according to both the inherited context and the assignment
3448          * context.
3449          */
3450         class FunctionalReturnContext extends Check.NestedCheckContext {
3451 
3452             FunctionalReturnContext(CheckContext enclosingContext) {
3453                 super(enclosingContext);
3454             }
3455 
3456             @Override
3457             public boolean compatible(Type found, Type req, Warner warn) {
3458                 //return type must be compatible in both current context and assignment context
3459                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3460             }
3461 
3462             @Override
3463             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3464                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3465             }
3466         }
3467 
3468         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3469 
3470             JCExpression expr;
3471             boolean expStmtExpected;
3472 
3473             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3474                 super(enclosingContext);
3475                 this.expr = expr;
3476             }
3477 
3478             @Override
3479             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3480                 if (expStmtExpected) {
3481                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3482                 } else {
3483                     super.report(pos, details);
3484                 }
3485             }
3486 
3487             @Override
3488             public boolean compatible(Type found, Type req, Warner warn) {
3489                 //a void return is compatible with an expression statement lambda
3490                 if (req.hasTag(VOID)) {
3491                     expStmtExpected = true;
3492                     return TreeInfo.isExpressionStatement(expr);
3493                 } else {
3494                     return super.compatible(found, req, warn);
3495                 }
3496             }
3497         }
3498 
3499         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3500             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3501                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3502                     new FunctionalReturnContext(resultInfo.checkContext);
3503 
3504             return descriptor.getReturnType() == Type.recoveryType ?
3505                     recoveryInfo :
3506                     new ResultInfo(KindSelector.VAL,
3507                             descriptor.getReturnType(), funcContext);
3508         }
3509 
3510         /**
3511         * Lambda compatibility. Check that given return types, thrown types, parameter types
3512         * are compatible with the expected functional interface descriptor. This means that:
3513         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3514         * types must be compatible with the return type of the expected descriptor.
3515         */
3516         void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
3517             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3518 
3519             //return values have already been checked - but if lambda has no return
3520             //values, we must ensure that void/value compatibility is correct;
3521             //this amounts at checking that, if a lambda body can complete normally,
3522             //the descriptor's return type must be void
3523             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3524                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3525                 Fragment msg =
3526                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3527                 checkContext.report(tree,
3528                                     diags.fragment(msg));
3529             }
3530 
3531             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3532             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3533                 checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3534             }
3535         }
3536 
3537         /* Map to hold 'fake' clinit methods. If a lambda is used to initialize a
3538          * static field and that lambda has type annotations, these annotations will
3539          * also be stored at these fake clinit methods.
3540          *
3541          * LambdaToMethod also use fake clinit methods so they can be reused.
3542          * Also as LTM is a phase subsequent to attribution, the methods from
3543          * clinits can be safely removed by LTM to save memory.
3544          */
3545         private Map<ClassSymbol, MethodSymbol> clinits = new HashMap<>();
3546 
3547         public MethodSymbol removeClinit(ClassSymbol sym) {
3548             return clinits.remove(sym);
3549         }
3550 
3551         /* This method returns an environment to be used to attribute a lambda
3552          * expression.
3553          *
3554          * The owner of this environment is a method symbol. If the current owner
3555          * is not a method, for example if the lambda is used to initialize
3556          * a field, then if the field is:
3557          *
3558          * - an instance field, we use the first constructor.
3559          * - a static field, we create a fake clinit method.
3560          */
3561         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3562             Env<AttrContext> lambdaEnv;
3563             Symbol owner = env.info.scope.owner;
3564             if (owner.kind == VAR && owner.owner.kind == TYP) {
3565                 //field initializer
3566                 ClassSymbol enclClass = owner.enclClass();
3567                 Symbol newScopeOwner = env.info.scope.owner;
3568                 /* if the field isn't static, then we can get the first constructor
3569                  * and use it as the owner of the environment. This is what
3570                  * LTM code is doing to look for type annotations so we are fine.
3571                  */
3572                 if ((owner.flags() & STATIC) == 0) {
3573                     Name constructorName = owner.isConcreteValueClass() ? names.vnew : names.init;
3574                     for (Symbol s : enclClass.members_field.getSymbolsByName(constructorName)) {
3575                         newScopeOwner = s;
3576                         break;
3577                     }
3578                 } else {
3579                     /* if the field is static then we need to create a fake clinit
3580                      * method, this method can later be reused by LTM.
3581                      */
3582                     MethodSymbol clinit = clinits.get(enclClass);
3583                     if (clinit == null) {
3584                         Type clinitType = new MethodType(List.nil(),
3585                                 syms.voidType, List.nil(), syms.methodClass);
3586                         clinit = new MethodSymbol(STATIC | SYNTHETIC | PRIVATE,
3587                                 names.clinit, clinitType, enclClass);
3588                         clinit.params = List.nil();
3589                         clinits.put(enclClass, clinit);
3590                     }
3591                     newScopeOwner = clinit;
3592                 }
3593                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(newScopeOwner)));
3594             } else {
3595                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3596             }
3597             lambdaEnv.info.yieldResult = null;
3598             lambdaEnv.info.isLambda = true;
3599             return lambdaEnv;
3600         }
3601 
3602     @Override
3603     public void visitReference(final JCMemberReference that) {
3604         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3605             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3606                 //method reference only allowed in assignment or method invocation/cast context
3607                 log.error(that.pos(), Errors.UnexpectedMref);
3608             }
3609             result = that.type = types.createErrorType(pt());
3610             return;
3611         }
3612         final Env<AttrContext> localEnv = env.dup(that);
3613         try {
3614             //attribute member reference qualifier - if this is a constructor
3615             //reference, the expected kind must be a type
3616             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3617 
3618             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3619                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3620                 if (!exprType.isErroneous() &&
3621                     exprType.isRaw() &&
3622                     that.typeargs != null) {
3623                     log.error(that.expr.pos(),
3624                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3625                                                  Fragments.MrefInferAndExplicitParams));
3626                     exprType = types.createErrorType(exprType);
3627                 }
3628             }
3629 
3630             if (exprType.isErroneous()) {
3631                 //if the qualifier expression contains problems,
3632                 //give up attribution of method reference
3633                 result = that.type = exprType;
3634                 return;
3635             }
3636 
3637             Symbol lhsSym = TreeInfo.symbol(that.expr);
3638             if (TreeInfo.isStaticSelector(that.expr, names)) {
3639                 // TODO - a bit hacky but...
3640                 if (lhsSym != null && lhsSym.isConcreteValueClass() && that.name == names.init) {
3641                     that.name = names.vnew;
3642                 }
3643                 //if the qualifier is a type, validate it; raw warning check is
3644                 //omitted as we don't know at this stage as to whether this is a
3645                 //raw selector (because of inference)
3646                 chk.validate(that.expr, env, false);
3647             } else {
3648                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
3649             }
3650             //attrib type-arguments
3651             List<Type> typeargtypes = List.nil();
3652             if (that.typeargs != null) {
3653                 typeargtypes = attribTypes(that.typeargs, localEnv);
3654             }
3655 
3656             boolean isTargetSerializable =
3657                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3658                     rs.isSerializable(pt());
3659             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
3660             Type currentTarget = targetInfo.target;
3661             Type desc = targetInfo.descriptor;
3662 
3663             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
3664             List<Type> argtypes = desc.getParameterTypes();
3665             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
3666 
3667             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
3668                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
3669             }
3670 
3671             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
3672             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
3673             try {
3674                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
3675                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
3676                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
3677             } finally {
3678                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
3679             }
3680 
3681             Symbol refSym = refResult.fst;
3682             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
3683 
3684             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
3685              *  JDK-8075541
3686              */
3687             if (refSym.kind != MTH) {
3688                 boolean targetError;
3689                 switch (refSym.kind) {
3690                     case ABSENT_MTH:
3691                     case MISSING_ENCL:
3692                         targetError = false;
3693                         break;
3694                     case WRONG_MTH:
3695                     case WRONG_MTHS:
3696                     case AMBIGUOUS:
3697                     case HIDDEN:
3698                     case STATICERR:
3699                         targetError = true;
3700                         break;
3701                     default:
3702                         Assert.error("unexpected result kind " + refSym.kind);
3703                         targetError = false;
3704                 }
3705 
3706                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
3707                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
3708                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
3709 
3710                 JCDiagnostic diag = diags.create(log.currentSource(), that,
3711                         targetError ?
3712                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
3713                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
3714 
3715                 if (targetError && currentTarget == Type.recoveryType) {
3716                     //a target error doesn't make sense during recovery stage
3717                     //as we don't know what actual parameter types are
3718                     result = that.type = currentTarget;
3719                     return;
3720                 } else {
3721                     if (targetError) {
3722                         resultInfo.checkContext.report(that, diag);
3723                     } else {
3724                         log.report(diag);
3725                     }
3726                     result = that.type = types.createErrorType(currentTarget);
3727                     return;
3728                 }
3729             }
3730 
3731             that.sym = refSym.isInitOrVNew() ? refSym.baseSymbol() : refSym;
3732             that.kind = lookupHelper.referenceKind(that.sym);
3733             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
3734 
3735             if (desc.getReturnType() == Type.recoveryType) {
3736                 // stop here
3737                 result = that.type = currentTarget;
3738                 return;
3739             }
3740 
3741             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3742                 Type enclosingType = exprType.getEnclosingType();
3743                 if (enclosingType != null && enclosingType.hasTag(CLASS)) {
3744                     // Check for the existence of an appropriate outer instance
3745                     rs.resolveImplicitThis(that.pos(), env, exprType);
3746                 }
3747             }
3748 
3749             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3750 
3751                 if (that.getMode() == ReferenceMode.INVOKE &&
3752                         TreeInfo.isStaticSelector(that.expr, names) &&
3753                         that.kind.isUnbound() &&
3754                         lookupHelper.site.isRaw()) {
3755                     chk.checkRaw(that.expr, localEnv);
3756                 }
3757 
3758                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
3759                         exprType.getTypeArguments().nonEmpty()) {
3760                     //static ref with class type-args
3761                     log.error(that.expr.pos(),
3762                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3763                                                  Fragments.StaticMrefWithTargs));
3764                     result = that.type = types.createErrorType(currentTarget);
3765                     return;
3766                 }
3767 
3768                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
3769                     // Check that super-qualified symbols are not abstract (JLS)
3770                     rs.checkNonAbstract(that.pos(), that.sym);
3771                 }
3772 
3773                 if (isTargetSerializable) {
3774                     chk.checkAccessFromSerializableElement(that, true);
3775                 }
3776             }
3777 
3778             ResultInfo checkInfo =
3779                     resultInfo.dup(newMethodTemplate(
3780                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
3781                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
3782                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3783 
3784             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
3785 
3786             if (that.kind.isUnbound() &&
3787                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
3788                 //re-generate inference constraints for unbound receiver
3789                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
3790                     //cannot happen as this has already been checked - we just need
3791                     //to regenerate the inference constraints, as that has been lost
3792                     //as a result of the call to inferenceContext.save()
3793                     Assert.error("Can't get here");
3794                 }
3795             }
3796 
3797             if (!refType.isErroneous()) {
3798                 refType = types.createMethodTypeWithReturn(refType,
3799                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
3800             }
3801 
3802             //go ahead with standard method reference compatibility check - note that param check
3803             //is a no-op (as this has been taken care during method applicability)
3804             boolean isSpeculativeRound =
3805                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3806 
3807             that.type = currentTarget; //avoids recovery at this stage
3808             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
3809             if (!isSpeculativeRound) {
3810                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
3811             }
3812             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3813         } catch (Types.FunctionDescriptorLookupError ex) {
3814             JCDiagnostic cause = ex.getDiagnostic();
3815             resultInfo.checkContext.report(that, cause);
3816             result = that.type = types.createErrorType(pt());
3817             return;
3818         }
3819     }
3820     //where
3821         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
3822             //if this is a constructor reference, the expected kind must be a type
3823             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
3824                                   KindSelector.VAL_TYP : KindSelector.TYP,
3825                                   Type.noType);
3826         }
3827 
3828 
3829     @SuppressWarnings("fallthrough")
3830     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
3831         InferenceContext inferenceContext = checkContext.inferenceContext();
3832         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
3833 
3834         Type resType;
3835         switch (tree.getMode()) {
3836             case NEW:
3837                 if (!tree.expr.type.isRaw()) {
3838                     resType = tree.expr.type;
3839                     break;
3840                 }
3841             default:
3842                 resType = refType.getReturnType();
3843         }
3844 
3845         Type incompatibleReturnType = resType;
3846 
3847         if (returnType.hasTag(VOID)) {
3848             incompatibleReturnType = null;
3849         }
3850 
3851         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
3852             if (resType.isErroneous() ||
3853                     new FunctionalReturnContext(checkContext).compatible(resType, returnType,
3854                             checkContext.checkWarner(tree, resType, returnType))) {
3855                 incompatibleReturnType = null;
3856             }
3857         }
3858 
3859         if (incompatibleReturnType != null) {
3860             Fragment msg =
3861                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
3862             checkContext.report(tree, diags.fragment(msg));
3863         } else {
3864             if (inferenceContext.free(refType)) {
3865                 // we need to wait for inference to finish and then replace inference vars in the referent type
3866                 inferenceContext.addFreeTypeListener(List.of(refType),
3867                         instantiatedContext -> {
3868                             tree.referentType = instantiatedContext.asInstType(refType);
3869                         });
3870             } else {
3871                 tree.referentType = refType;
3872             }
3873         }
3874 
3875         if (!speculativeAttr) {
3876             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
3877                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
3878             }
3879         }
3880     }
3881 
3882     boolean checkExConstraints(
3883             List<Type> thrownByFuncExpr,
3884             List<Type> thrownAtFuncType,
3885             InferenceContext inferenceContext) {
3886         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
3887          *  are not proper types
3888          */
3889         List<Type> nonProperList = thrownAtFuncType.stream()
3890                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
3891         List<Type> properList = thrownAtFuncType.diff(nonProperList);
3892 
3893         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
3894          *  in the throws clause of the invocation type of the method reference's compile-time
3895          *  declaration
3896          */
3897         List<Type> checkedList = thrownByFuncExpr.stream()
3898                 .filter(e -> chk.isChecked(e)).collect(List.collector());
3899 
3900         /** If n = 0 (the function type's throws clause consists only of proper types), then
3901          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
3902          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
3903          *  reduces to true
3904          */
3905         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
3906         for (Type checked : checkedList) {
3907             boolean isSubtype = false;
3908             for (Type proper : properList) {
3909                 if (types.isSubtype(checked, proper)) {
3910                     isSubtype = true;
3911                     break;
3912                 }
3913             }
3914             if (!isSubtype) {
3915                 uncaughtByProperTypes.add(checked);
3916             }
3917         }
3918 
3919         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
3920             return false;
3921         }
3922 
3923         /** If n > 0, the constraint reduces to a set of subtyping constraints:
3924          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
3925          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
3926          */
3927         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
3928         uncaughtByProperTypes.forEach(checkedEx -> {
3929             nonProperAsUndet.forEach(nonProper -> {
3930                 types.isSubtype(checkedEx, nonProper);
3931             });
3932         });
3933 
3934         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
3935          */
3936         nonProperAsUndet.stream()
3937                 .filter(t -> t.hasTag(UNDETVAR))
3938                 .forEach(t -> ((UndetVar)t).setThrow());
3939         return true;
3940     }
3941 
3942     /**
3943      * Set functional type info on the underlying AST. Note: as the target descriptor
3944      * might contain inference variables, we might need to register an hook in the
3945      * current inference context.
3946      */
3947     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
3948             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
3949         if (checkContext.inferenceContext().free(descriptorType)) {
3950             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
3951                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
3952                     inferenceContext.asInstType(primaryTarget), checkContext));
3953         } else {
3954             if (pt.hasTag(CLASS)) {
3955                 fExpr.target = primaryTarget;
3956             }
3957             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3958                     pt != Type.recoveryType) {
3959                 //check that functional interface class is well-formed
3960                 try {
3961                     /* Types.makeFunctionalInterfaceClass() may throw an exception
3962                      * when it's executed post-inference. See the listener code
3963                      * above.
3964                      */
3965                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
3966                             names.empty, fExpr.target, ABSTRACT);
3967                     if (csym != null) {
3968                         chk.checkImplementations(env.tree, csym, csym);
3969                         try {
3970                             //perform an additional functional interface check on the synthetic class,
3971                             //as there may be spurious errors for raw targets - because of existing issues
3972                             //with membership and inheritance (see JDK-8074570).
3973                             csym.flags_field |= INTERFACE;
3974                             types.findDescriptorType(csym.type);
3975                         } catch (FunctionDescriptorLookupError err) {
3976                             resultInfo.checkContext.report(fExpr,
3977                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
3978                         }
3979                     }
3980                 } catch (Types.FunctionDescriptorLookupError ex) {
3981                     JCDiagnostic cause = ex.getDiagnostic();
3982                     resultInfo.checkContext.report(env.tree, cause);
3983                 }
3984             }
3985         }
3986     }
3987 
3988     public void visitParens(JCParens tree) {
3989         Type owntype = attribTree(tree.expr, env, resultInfo);
3990         result = check(tree, owntype, pkind(), resultInfo);
3991         Symbol sym = TreeInfo.symbol(tree);
3992         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
3993             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
3994     }
3995 
3996     public void visitAssign(JCAssign tree) {
3997         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
3998         Type capturedType = capture(owntype);
3999         attribExpr(tree.rhs, env, owntype);
4000         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
4001     }
4002 
4003     public void visitAssignop(JCAssignOp tree) {
4004         // Attribute arguments.
4005         Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
4006         Type operand = attribExpr(tree.rhs, env);
4007         // Find operator.
4008         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
4009         if (operator != operators.noOpSymbol &&
4010                 !owntype.isErroneous() &&
4011                 !operand.isErroneous()) {
4012             chk.checkDivZero(tree.rhs.pos(), operator, operand);
4013             chk.checkCastable(tree.rhs.pos(),
4014                               operator.type.getReturnType(),
4015                               owntype);
4016             chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
4017         }
4018         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4019     }
4020 
4021     public void visitUnary(JCUnary tree) {
4022         // Attribute arguments.
4023         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
4024             ? attribTree(tree.arg, env, varAssignmentInfo)
4025             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
4026 
4027         // Find operator.
4028         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
4029         Type owntype = types.createErrorType(tree.type);
4030         if (operator != operators.noOpSymbol &&
4031                 !argtype.isErroneous()) {
4032             owntype = (tree.getTag().isIncOrDecUnaryOp())
4033                 ? tree.arg.type
4034                 : operator.type.getReturnType();
4035             int opc = operator.opcode;
4036 
4037             // If the argument is constant, fold it.
4038             if (argtype.constValue() != null) {
4039                 Type ctype = cfolder.fold1(opc, argtype);
4040                 if (ctype != null) {
4041                     owntype = cfolder.coerce(ctype, owntype);
4042                 }
4043             }
4044         }
4045         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4046         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4047     }
4048 
4049     public void visitBinary(JCBinary tree) {
4050         // Attribute arguments.
4051         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4052         // x && y
4053         // include x's bindings when true in y
4054 
4055         // x || y
4056         // include x's bindings when false in y
4057 
4058         MatchBindings lhsBindings = matchBindings;
4059         List<BindingSymbol> propagatedBindings;
4060         switch (tree.getTag()) {
4061             case AND:
4062                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4063                 break;
4064             case OR:
4065                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4066                 break;
4067             default:
4068                 propagatedBindings = List.nil();
4069                 break;
4070         }
4071         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4072         Type right;
4073         try {
4074             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4075         } finally {
4076             rhsEnv.info.scope.leave();
4077         }
4078 
4079         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4080 
4081         // Find operator.
4082         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4083         Type owntype = types.createErrorType(tree.type);
4084         if (operator != operators.noOpSymbol &&
4085                 !left.isErroneous() &&
4086                 !right.isErroneous()) {
4087             owntype = operator.type.getReturnType();
4088             int opc = operator.opcode;
4089             // If both arguments are constants, fold them.
4090             if (left.constValue() != null && right.constValue() != null) {
4091                 Type ctype = cfolder.fold2(opc, left, right);
4092                 if (ctype != null) {
4093                     owntype = cfolder.coerce(ctype, owntype);
4094                 }
4095             }
4096 
4097             // Check that argument types of a reference ==, != are
4098             // castable to each other, (JLS 15.21).  Note: unboxing
4099             // comparisons will not have an acmp* opc at this point.
4100             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4101                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4102                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4103                 }
4104             }
4105 
4106             chk.checkDivZero(tree.rhs.pos(), operator, right);
4107         }
4108         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4109     }
4110 
4111     public void visitTypeCast(final JCTypeCast tree) {
4112         Type clazztype = attribType(tree.clazz, env);
4113         chk.validate(tree.clazz, env, false);
4114         //a fresh environment is required for 292 inference to work properly ---
4115         //see Infer.instantiatePolymorphicSignatureInstance()
4116         Env<AttrContext> localEnv = env.dup(tree);
4117         //should we propagate the target type?
4118         final ResultInfo castInfo;
4119         JCExpression expr = TreeInfo.skipParens(tree.expr);
4120         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4121         if (isPoly) {
4122             //expression is a poly - we need to propagate target type info
4123             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4124                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4125                 @Override
4126                 public boolean compatible(Type found, Type req, Warner warn) {
4127                     return types.isCastable(found, req, warn);
4128                 }
4129             });
4130         } else {
4131             //standalone cast - target-type info is not propagated
4132             castInfo = unknownExprInfo;
4133         }
4134         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4135         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4136         if (exprtype.constValue() != null)
4137             owntype = cfolder.coerce(exprtype, owntype);
4138         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4139         if (!isPoly)
4140             chk.checkRedundantCast(localEnv, tree);
4141     }
4142 
4143     public void visitTypeTest(JCInstanceOf tree) {
4144         Type exprtype = chk.checkNullOrRefType(
4145                 tree.expr.pos(), attribExpr(tree.expr, env));
4146         Type clazztype;
4147         JCTree typeTree;
4148         if (tree.pattern.getTag() == BINDINGPATTERN ||
4149             tree.pattern.getTag() == PARENTHESIZEDPATTERN ||
4150             tree.pattern.getTag() == RECORDPATTERN) {
4151             attribExpr(tree.pattern, env, exprtype);
4152             clazztype = tree.pattern.type;
4153             if (types.isSubtype(exprtype, clazztype) &&
4154                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4155                 tree.pattern.getTag() != RECORDPATTERN) {
4156                 if (!allowUnconditionalPatternsInstanceOf) {
4157                     log.error(tree.pos(), Errors.InstanceofPatternNoSubtype(exprtype, clazztype));
4158                 } else if (preview.isPreview(Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF)) {
4159                     preview.warnPreview(tree.pattern.pos(), Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF);
4160                 }
4161             }
4162             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4163         } else {
4164             clazztype = attribType(tree.pattern, env);
4165             typeTree = tree.pattern;
4166             chk.validate(typeTree, env, false);
4167         }
4168         if (!clazztype.hasTag(TYPEVAR)) {
4169             clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4170         }
4171         if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4172             boolean valid = false;
4173             if (allowReifiableTypesInInstanceof) {
4174                 valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4175             } else {
4176                 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(),
4177                           Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4178                 allowReifiableTypesInInstanceof = true;
4179             }
4180             if (!valid) {
4181                 clazztype = types.createErrorType(clazztype);
4182             }
4183         }
4184         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4185         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4186     }
4187 
4188     private boolean checkCastablePattern(DiagnosticPosition pos,
4189                                          Type exprType,
4190                                          Type pattType) {
4191         Warner warner = new Warner();
4192         // if any type is erroneous, the problem is reported elsewhere
4193         if (exprType.isErroneous() || pattType.isErroneous()) {
4194             return false;
4195         }
4196         if (!types.isCastable(exprType, pattType, warner)) {
4197             chk.basicHandler.report(pos,
4198                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4199             return false;
4200         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4201                    (!exprType.isPrimitive() ||
4202                     !pattType.isPrimitive() ||
4203                     !types.isSameType(exprType, pattType))) {
4204             chk.basicHandler.report(pos,
4205                     diags.fragment(Fragments.NotApplicableTypes(exprType, pattType)));
4206             return false;
4207         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4208             log.error(pos,
4209                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4210             return false;
4211         } else {
4212             return true;
4213         }
4214     }
4215 
4216     public void visitBindingPattern(JCBindingPattern tree) {
4217         Type type;
4218         if (tree.var.vartype != null) {
4219             type = attribType(tree.var.vartype, env);
4220         } else {
4221             type = resultInfo.pt;
4222         }
4223         tree.type = tree.var.type = type;
4224         BindingSymbol v = new BindingSymbol(tree.var.mods.flags, tree.var.name, type, env.info.scope.owner);
4225         v.pos = tree.pos;
4226         tree.var.sym = v;
4227         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4228             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4229         }
4230         if (tree.var.vartype != null) {
4231             annotate.annotateLater(tree.var.mods.annotations, env, v, tree.pos());
4232             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v, tree.var.pos());
4233             annotate.flush();
4234         }
4235         chk.validate(tree.var.vartype, env, true);
4236         result = tree.type;
4237         matchBindings = new MatchBindings(List.of(v), List.nil());
4238     }
4239 
4240     @Override
4241     public void visitRecordPattern(JCRecordPattern tree) {
4242         Type type = attribType(tree.deconstructor, env);
4243         if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4244             Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4245             if (inferred == null) {
4246                 log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4247             } else {
4248                 type = inferred;
4249             }
4250         }
4251         tree.type = tree.deconstructor.type = type;
4252         Type site = types.capture(tree.type);
4253         List<Type> expectedRecordTypes;
4254         if (site.tsym.kind == Kind.TYP && ((ClassSymbol) site.tsym).isRecord()) {
4255             ClassSymbol record = (ClassSymbol) site.tsym;
4256             expectedRecordTypes = record.getRecordComponents()
4257                                         .stream()
4258                                         .map(rc -> types.memberType(site, rc))
4259                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4260                                         .collect(List.collector());
4261             tree.record = record;
4262         } else {
4263             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4264             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4265                                 .limit(tree.nested.size())
4266                                 .collect(List.collector());
4267             tree.record = syms.errSymbol;
4268         }
4269         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4270         List<Type> recordTypes = expectedRecordTypes;
4271         List<JCPattern> nestedPatterns = tree.nested;
4272         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4273         try {
4274             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4275                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4276                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4277                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4278                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4279                 nestedPatterns = nestedPatterns.tail;
4280                 recordTypes = recordTypes.tail;
4281             }
4282             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4283                 while (nestedPatterns.nonEmpty()) {
4284                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4285                     nestedPatterns = nestedPatterns.tail;
4286                 }
4287                 List<Type> nestedTypes =
4288                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4289                 log.error(tree.pos(),
4290                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4291                                                                  nestedTypes));
4292             }
4293         } finally {
4294             localEnv.info.scope.leave();
4295         }
4296         chk.validate(tree.deconstructor, env, true);
4297         result = tree.type;
4298         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4299     }
4300 
4301     public void visitParenthesizedPattern(JCParenthesizedPattern tree) {
4302         attribExpr(tree.pattern, env);
4303         result = tree.type = tree.pattern.type;
4304     }
4305 
4306     public void visitIndexed(JCArrayAccess tree) {
4307         Type owntype = types.createErrorType(tree.type);
4308         Type atype = attribExpr(tree.indexed, env);
4309         attribExpr(tree.index, env, syms.intType);
4310         if (types.isArray(atype))
4311             owntype = types.elemtype(atype);
4312         else if (!atype.hasTag(ERROR))
4313             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4314         if (!pkind().contains(KindSelector.VAL))
4315             owntype = capture(owntype);
4316         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4317     }
4318 
4319     public void visitIdent(JCIdent tree) {
4320         Symbol sym;
4321 
4322         // Find symbol
4323         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4324             // If we are looking for a method, the prototype `pt' will be a
4325             // method type with the type of the call's arguments as parameters.
4326             env.info.pendingResolutionPhase = null;
4327             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4328         } else if (tree.sym != null && tree.sym.kind != VAR) {
4329             sym = tree.sym;
4330         } else {
4331             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4332         }
4333         tree.sym = sym;
4334 
4335         // Also find the environment current for the class where
4336         // sym is defined (`symEnv').
4337         Env<AttrContext> symEnv = env;
4338         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4339             sym.kind.matches(KindSelector.VAL_MTH) &&
4340             sym.owner.kind == TYP &&
4341             tree.name != names._this && tree.name != names._super) {
4342 
4343             // Find environment in which identifier is defined.
4344             while (symEnv.outer != null &&
4345                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4346                 symEnv = symEnv.outer;
4347             }
4348         }
4349 
4350         // If symbol is a variable, ...
4351         if (sym.kind == VAR) {
4352             VarSymbol v = (VarSymbol)sym;
4353 
4354             // ..., evaluate its initializer, if it has one, and check for
4355             // illegal forward reference.
4356             checkInit(tree, env, v, false);
4357 
4358             // If we are expecting a variable (as opposed to a value), check
4359             // that the variable is assignable in the current environment.
4360             if (KindSelector.ASG.subset(pkind()))
4361                 checkAssignable(tree.pos(), v, null, env);
4362         }
4363 
4364         // In a constructor body,
4365         // if symbol is a field or instance method, check that it is
4366         // not accessed before the supertype constructor is called.
4367         if (symEnv.info.isSelfCall &&
4368             sym.kind.matches(KindSelector.VAL_MTH) &&
4369             sym.owner.kind == TYP &&
4370             (sym.flags() & STATIC) == 0) {
4371             chk.earlyRefError(tree.pos(), sym.kind == VAR ?
4372                                           sym : thisSym(tree.pos(), env));
4373         }
4374         Env<AttrContext> env1 = env;
4375         if (sym.kind != ERR && sym.kind != TYP &&
4376             sym.owner != null && sym.owner != env1.enclClass.sym) {
4377             // If the found symbol is inaccessible, then it is
4378             // accessed through an enclosing instance.  Locate this
4379             // enclosing instance:
4380             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4381                 env1 = env1.outer;
4382         }
4383 
4384         if (env.info.isSerializable) {
4385             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4386         }
4387 
4388         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4389     }
4390 
4391     public void visitSelect(JCFieldAccess tree) {
4392         // Determine the expected kind of the qualifier expression.
4393         KindSelector skind = KindSelector.NIL;
4394         if (tree.name == names._this || tree.name == names._super ||
4395                 tree.name == names._class)
4396         {
4397             skind = KindSelector.TYP;
4398         } else {
4399             if (pkind().contains(KindSelector.PCK))
4400                 skind = KindSelector.of(skind, KindSelector.PCK);
4401             if (pkind().contains(KindSelector.TYP))
4402                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4403             if (pkind().contains(KindSelector.VAL_MTH))
4404                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4405         }
4406 
4407         // Attribute the qualifier expression, and determine its symbol (if any).
4408         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
4409         Assert.check(site == tree.selected.type);
4410         if (allowPrimitiveClasses && tree.name == names._class && site.isPrimitiveClass()) {
4411             /* JDK-8269956: Where a reflective (class) literal is needed, the unqualified Point.class is
4412              * always the "primary" mirror - representing the primitive reference runtime type - thereby
4413              * always matching the behavior of Object::getClass
4414              */
4415              if (!tree.selected.hasTag(SELECT) || ((JCFieldAccess) tree.selected).name != names.val) {
4416                  tree.selected.setType(site = site.referenceProjection());
4417              }
4418         }
4419         if (!pkind().contains(KindSelector.TYP_PCK))
4420             site = capture(site); // Capture field access
4421 
4422         // don't allow T.class T[].class, etc
4423         if (skind == KindSelector.TYP) {
4424             Type elt = site;
4425             while (elt.hasTag(ARRAY))
4426                 elt = ((ArrayType)elt).elemtype;
4427             if (elt.hasTag(TYPEVAR)) {
4428                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4429                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4430                 tree.sym = tree.type.tsym;
4431                 return;
4432             }
4433         }
4434 
4435         // If qualifier symbol is a type or `super', assert `selectSuper'
4436         // for the selection. This is relevant for determining whether
4437         // protected symbols are accessible.
4438         Symbol sitesym = TreeInfo.symbol(tree.selected);
4439         boolean selectSuperPrev = env.info.selectSuper;
4440         env.info.selectSuper =
4441             sitesym != null &&
4442             sitesym.name == names._super;
4443 
4444         // Determine the symbol represented by the selection.
4445         env.info.pendingResolutionPhase = null;
4446         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
4447         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4448             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4449             sym = syms.errSymbol;
4450         }
4451         if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
4452             site = capture(site);
4453             sym = selectSym(tree, sitesym, site, env, resultInfo);
4454         }
4455         boolean varArgs = env.info.lastResolveVarargs();
4456         tree.sym = sym;
4457 
4458         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4459             site = types.skipTypeVars(site, true);
4460         }
4461 
4462         // If that symbol is a variable, ...
4463         if (sym.kind == VAR) {
4464             VarSymbol v = (VarSymbol)sym;
4465 
4466             // ..., evaluate its initializer, if it has one, and check for
4467             // illegal forward reference.
4468             checkInit(tree, env, v, true);
4469 
4470             // If we are expecting a variable (as opposed to a value), check
4471             // that the variable is assignable in the current environment.
4472             if (KindSelector.ASG.subset(pkind()))
4473                 checkAssignable(tree.pos(), v, tree.selected, env);
4474         }
4475 
4476         if (sitesym != null &&
4477                 sitesym.kind == VAR &&
4478                 ((VarSymbol)sitesym).isResourceVariable() &&
4479                 sym.kind == MTH &&
4480                 sym.name.equals(names.close) &&
4481                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
4482                 env.info.lint.isEnabled(LintCategory.TRY)) {
4483             log.warning(LintCategory.TRY, tree, Warnings.TryExplicitCloseCall);
4484         }
4485 
4486         // Disallow selecting a type from an expression
4487         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4488             tree.type = check(tree.selected, pt(),
4489                               sitesym == null ?
4490                                       KindSelector.VAL : sitesym.kind.toSelector(),
4491                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4492         }
4493 
4494         if (isType(sitesym)) {
4495             if (sym.name == names._this || sym.name == names._super) {
4496                 // If `C' is the currently compiled class, check that
4497                 // `C.this' does not appear in an explicit call to a constructor
4498                 // also make sure that `super` is not used in constructor invocations
4499                 if (env.info.isSelfCall &&
4500                         ((sym.name == names._this &&
4501                         site.tsym == env.enclClass.sym) ||
4502                         sym.name == names._super && env.info.constructorArgs &&
4503                         (sitesym.isInterface() || site.tsym == env.enclClass.sym))) {
4504                     chk.earlyRefError(tree.pos(), sym);
4505                 }
4506             } else {
4507                 // Check if type-qualified fields or methods are static (JLS)
4508                 if ((sym.flags() & STATIC) == 0 &&
4509                     sym.name != names._super &&
4510                     (sym.kind == VAR || sym.kind == MTH)) {
4511                     rs.accessBase(rs.new StaticError(sym),
4512                               tree.pos(), site, sym.name, true);
4513                 }
4514             }
4515         } else if (sym.kind != ERR &&
4516                    (sym.flags() & STATIC) != 0 &&
4517                    sym.name != names._class) {
4518             // If the qualified item is not a type and the selected item is static, report
4519             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4520             if (!sym.owner.isAnonymous()) {
4521                 chk.warnStatic(tree, Warnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4522             } else {
4523                 chk.warnStatic(tree, Warnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4524             }
4525         }
4526 
4527         // If we are selecting an instance member via a `super', ...
4528         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4529 
4530             // Check that super-qualified symbols are not abstract (JLS)
4531             rs.checkNonAbstract(tree.pos(), sym);
4532 
4533             if (site.isRaw()) {
4534                 // Determine argument types for site.
4535                 Type site1 = types.asSuper(env.enclClass.sym.type.referenceProjectionOrSelf(), site.tsym);
4536                 if (site1 != null) site = site1;
4537             }
4538         }
4539 
4540         if (env.info.isSerializable) {
4541             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4542         }
4543 
4544         env.info.selectSuper = selectSuperPrev;
4545         result = checkId(tree, site, sym, env, resultInfo);
4546     }
4547     //where
4548         /** Determine symbol referenced by a Select expression,
4549          *
4550          *  @param tree   The select tree.
4551          *  @param site   The type of the selected expression,
4552          *  @param env    The current environment.
4553          *  @param resultInfo The current result.
4554          */
4555         private Symbol selectSym(JCFieldAccess tree,
4556                                  Symbol location,
4557                                  Type site,
4558                                  Env<AttrContext> env,
4559                                  ResultInfo resultInfo) {
4560             DiagnosticPosition pos = tree.pos();
4561             Name name = tree.name;
4562             switch (site.getTag()) {
4563             case PACKAGE:
4564                 return rs.accessBase(
4565                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4566                     pos, location, site, name, true);
4567             case ARRAY:
4568             case CLASS:
4569                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4570                     return rs.resolveQualifiedMethod(
4571                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4572                 } else if (name == names._this || name == names._super) {
4573                     return rs.resolveSelf(pos, env, site.tsym, name);
4574                 } else if (name == names._class) {
4575                     // In this case, we have already made sure in
4576                     // visitSelect that qualifier expression is a type.
4577                     return syms.getClassField(site, types);
4578                 } else if (allowPrimitiveClasses && site.isPrimitiveClass() && isType(location) && resultInfo.pkind.contains(KindSelector.TYP) && (name == names.ref || name == names.val)) {
4579                     return site.tsym;
4580                 } else {
4581                     // We are seeing a plain identifier as selector.
4582                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
4583                         sym = rs.accessBase(sym, pos, location, site, name, true);
4584                     return sym;
4585                 }
4586             case WILDCARD:
4587                 throw new AssertionError(tree);
4588             case TYPEVAR:
4589                 // Normally, site.getUpperBound() shouldn't be null.
4590                 // It should only happen during memberEnter/attribBase
4591                 // when determining the supertype which *must* be
4592                 // done before attributing the type variables.  In
4593                 // other words, we are seeing this illegal program:
4594                 // class B<T> extends A<T.foo> {}
4595                 Symbol sym = (site.getUpperBound() != null)
4596                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
4597                     : null;
4598                 if (sym == null) {
4599                     log.error(pos, Errors.TypeVarCantBeDeref);
4600                     return syms.errSymbol;
4601                 } else {
4602                     Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
4603                         rs.new AccessError(env, site, sym) :
4604                                 sym;
4605                     rs.accessBase(sym2, pos, location, site, name, true);
4606                     return sym;
4607                 }
4608             case ERROR:
4609                 // preserve identifier names through errors
4610                 return types.createErrorType(name, site.tsym, site).tsym;
4611             default:
4612                 // The qualifier expression is of a primitive type -- only
4613                 // .class is allowed for these.
4614                 if (name == names._class) {
4615                     // In this case, we have already made sure in Select that
4616                     // qualifier expression is a type.
4617                     return syms.getClassField(site, types);
4618                 } else {
4619                     log.error(pos, Errors.CantDeref(site));
4620                     return syms.errSymbol;
4621                 }
4622             }
4623         }
4624 
4625         /** Determine type of identifier or select expression and check that
4626          *  (1) the referenced symbol is not deprecated
4627          *  (2) the symbol's type is safe (@see checkSafe)
4628          *  (3) if symbol is a variable, check that its type and kind are
4629          *      compatible with the prototype and protokind.
4630          *  (4) if symbol is an instance field of a raw type,
4631          *      which is being assigned to, issue an unchecked warning if its
4632          *      type changes under erasure.
4633          *  (5) if symbol is an instance method of a raw type, issue an
4634          *      unchecked warning if its argument types change under erasure.
4635          *  If checks succeed:
4636          *    If symbol is a constant, return its constant type
4637          *    else if symbol is a method, return its result type
4638          *    otherwise return its type.
4639          *  Otherwise return errType.
4640          *
4641          *  @param tree       The syntax tree representing the identifier
4642          *  @param site       If this is a select, the type of the selected
4643          *                    expression, otherwise the type of the current class.
4644          *  @param sym        The symbol representing the identifier.
4645          *  @param env        The current environment.
4646          *  @param resultInfo    The expected result
4647          */
4648         Type checkId(JCTree tree,
4649                      Type site,
4650                      Symbol sym,
4651                      Env<AttrContext> env,
4652                      ResultInfo resultInfo) {
4653             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
4654                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
4655                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4656         }
4657 
4658         Type checkMethodIdInternal(JCTree tree,
4659                      Type site,
4660                      Symbol sym,
4661                      Env<AttrContext> env,
4662                      ResultInfo resultInfo) {
4663             if (resultInfo.pkind.contains(KindSelector.POLY)) {
4664                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
4665             } else {
4666                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4667             }
4668         }
4669 
4670         Type checkIdInternal(JCTree tree,
4671                      Type site,
4672                      Symbol sym,
4673                      Type pt,
4674                      Env<AttrContext> env,
4675                      ResultInfo resultInfo) {
4676             if (pt.isErroneous()) {
4677                 return types.createErrorType(site);
4678             }
4679             Type owntype; // The computed type of this identifier occurrence.
4680             switch (sym.kind) {
4681             case TYP:
4682                 // For types, the computed type equals the symbol's type,
4683                 // except for three situations:
4684                 owntype = sym.type;
4685                 if (owntype.hasTag(CLASS)) {
4686                     if (allowPrimitiveClasses) {
4687                         Assert.check(owntype.getFlavor() != Flavor.X_Typeof_X);
4688                     }
4689                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
4690                     Type ownOuter = owntype.getEnclosingType();
4691 
4692                     // (a) If symbol is a primitive class and its reference projection
4693                     // is requested via the .ref notation, then adjust the computed type to
4694                     // reflect this.
4695                     if (allowPrimitiveClasses && owntype.isPrimitiveClass() && tree.hasTag(SELECT) && ((JCFieldAccess) tree).name == names.ref) {
4696                         owntype = new ClassType(owntype.getEnclosingType(), owntype.getTypeArguments(), (TypeSymbol)sym, owntype.getMetadata(), Flavor.L_TypeOf_Q);
4697                     }
4698 
4699                     // (b) If the symbol's type is parameterized, erase it
4700                     // because no type parameters were given.
4701                     // We recover generic outer type later in visitTypeApply.
4702                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
4703                         owntype = types.erasure(owntype);
4704                     }
4705 
4706                     // (c) If the symbol's type is an inner class, then
4707                     // we have to interpret its outer type as a superclass
4708                     // of the site type. Example:
4709                     //
4710                     // class Tree<A> { class Visitor { ... } }
4711                     // class PointTree extends Tree<Point> { ... }
4712                     // ...PointTree.Visitor...
4713                     //
4714                     // Then the type of the last expression above is
4715                     // Tree<Point>.Visitor.
4716                     else if (ownOuter.hasTag(CLASS) && site != ownOuter) {
4717                         Type normOuter = site;
4718                         if (normOuter.hasTag(CLASS)) {
4719                             normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
4720                         }
4721                         if (normOuter == null) // perhaps from an import
4722                             normOuter = types.erasure(ownOuter);
4723                         if (normOuter != ownOuter)
4724                             owntype = new ClassType(
4725                                 normOuter, List.nil(), owntype.tsym,
4726                                 owntype.getMetadata(), owntype.getFlavor());
4727                     }
4728                 }
4729                 break;
4730             case VAR:
4731                 VarSymbol v = (VarSymbol)sym;
4732 
4733                 if (env.info.enclVar != null
4734                         && v.type.hasTag(NONE)) {
4735                     //self reference to implicitly typed variable declaration
4736                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
4737                     return tree.type = v.type = types.createErrorType(v.type);
4738                 }
4739 
4740                 // Test (4): if symbol is an instance field of a raw type,
4741                 // which is being assigned to, issue an unchecked warning if
4742                 // its type changes under erasure.
4743                 if (KindSelector.ASG.subset(pkind()) &&
4744                     v.owner.kind == TYP &&
4745                     (v.flags() & STATIC) == 0 &&
4746                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4747                     Type s = types.asOuterSuper(site, v.owner);
4748                     if (s != null &&
4749                         s.isRaw() &&
4750                         !types.isSameType(v.type, v.erasure(types))) {
4751                         chk.warnUnchecked(tree.pos(), Warnings.UncheckedAssignToVar(v, s));
4752                     }
4753                 }
4754                 // The computed type of a variable is the type of the
4755                 // variable symbol, taken as a member of the site type.
4756                 owntype = (sym.owner.kind == TYP &&
4757                            sym.name != names._this && sym.name != names._super)
4758                     ? types.memberType(site, sym)
4759                     : sym.type;
4760 
4761                 // If the variable is a constant, record constant value in
4762                 // computed type.
4763                 if (v.getConstValue() != null && isStaticReference(tree))
4764                     owntype = owntype.constType(v.getConstValue());
4765 
4766                 if (resultInfo.pkind == KindSelector.VAL) {
4767                     owntype = capture(owntype); // capture "names as expressions"
4768                 }
4769                 break;
4770             case MTH: {
4771                 owntype = checkMethod(site, sym,
4772                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
4773                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
4774                         resultInfo.pt.getTypeArguments());
4775                 break;
4776             }
4777             case PCK: case ERR:
4778                 owntype = sym.type;
4779                 break;
4780             default:
4781                 throw new AssertionError("unexpected kind: " + sym.kind +
4782                                          " in tree " + tree);
4783             }
4784 
4785             // Emit a `deprecation' warning if symbol is deprecated.
4786             // (for constructors (but not for constructor references), the error
4787             // was given when the constructor was resolved)
4788 
4789             if (!names.isInitOrVNew(sym.name) || tree.hasTag(REFERENCE)) {
4790                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
4791                 chk.checkSunAPI(tree.pos(), sym);
4792                 chk.checkProfile(tree.pos(), sym);
4793                 chk.checkPreview(tree.pos(), env.info.scope.owner, sym);
4794             }
4795 
4796             // If symbol is a variable, check that its type and
4797             // kind are compatible with the prototype and protokind.
4798             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
4799         }
4800 
4801         /** Check that variable is initialized and evaluate the variable's
4802          *  initializer, if not yet done. Also check that variable is not
4803          *  referenced before it is defined.
4804          *  @param tree    The tree making up the variable reference.
4805          *  @param env     The current environment.
4806          *  @param v       The variable's symbol.
4807          */
4808         private void checkInit(JCTree tree,
4809                                Env<AttrContext> env,
4810                                VarSymbol v,
4811                                boolean onlyWarning) {
4812             // A forward reference is diagnosed if the declaration position
4813             // of the variable is greater than the current tree position
4814             // and the tree and variable definition occur in the same class
4815             // definition.  Note that writes don't count as references.
4816             // This check applies only to class and instance
4817             // variables.  Local variables follow different scope rules,
4818             // and are subject to definite assignment checking.
4819             Env<AttrContext> initEnv = enclosingInitEnv(env);
4820             if (initEnv != null &&
4821                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
4822                 v.owner.kind == TYP &&
4823                 v.owner == env.info.scope.owner.enclClass() &&
4824                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
4825                 (!env.tree.hasTag(ASSIGN) ||
4826                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
4827                 if (!onlyWarning || isStaticEnumField(v)) {
4828                     Error errkey = (initEnv.info.enclVar == v) ?
4829                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
4830                     log.error(tree.pos(), errkey);
4831                 } else if (useBeforeDeclarationWarning) {
4832                     Warning warnkey = (initEnv.info.enclVar == v) ?
4833                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
4834                     log.warning(tree.pos(), warnkey);
4835                 }
4836             }
4837 
4838             v.getConstValue(); // ensure initializer is evaluated
4839 
4840             checkEnumInitializer(tree, env, v);
4841         }
4842 
4843         /**
4844          * Returns the enclosing init environment associated with this env (if any). An init env
4845          * can be either a field declaration env or a static/instance initializer env.
4846          */
4847         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
4848             while (true) {
4849                 switch (env.tree.getTag()) {
4850                     case VARDEF:
4851                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
4852                         if (vdecl.sym.owner.kind == TYP) {
4853                             //field
4854                             return env;
4855                         }
4856                         break;
4857                     case BLOCK:
4858                         if (env.next.tree.hasTag(CLASSDEF)) {
4859                             //instance/static initializer
4860                             return env;
4861                         }
4862                         break;
4863                     case METHODDEF:
4864                     case CLASSDEF:
4865                     case TOPLEVEL:
4866                         return null;
4867                 }
4868                 Assert.checkNonNull(env.next);
4869                 env = env.next;
4870             }
4871         }
4872 
4873         /**
4874          * Check for illegal references to static members of enum.  In
4875          * an enum type, constructors and initializers may not
4876          * reference its static members unless they are constant.
4877          *
4878          * @param tree    The tree making up the variable reference.
4879          * @param env     The current environment.
4880          * @param v       The variable's symbol.
4881          * @jls 8.9 Enum Types
4882          */
4883         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
4884             // JLS:
4885             //
4886             // "It is a compile-time error to reference a static field
4887             // of an enum type that is not a compile-time constant
4888             // (15.28) from constructors, instance initializer blocks,
4889             // or instance variable initializer expressions of that
4890             // type. It is a compile-time error for the constructors,
4891             // instance initializer blocks, or instance variable
4892             // initializer expressions of an enum constant e to refer
4893             // to itself or to an enum constant of the same type that
4894             // is declared to the right of e."
4895             if (isStaticEnumField(v)) {
4896                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
4897 
4898                 if (enclClass == null || enclClass.owner == null)
4899                     return;
4900 
4901                 // See if the enclosing class is the enum (or a
4902                 // subclass thereof) declaring v.  If not, this
4903                 // reference is OK.
4904                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
4905                     return;
4906 
4907                 // If the reference isn't from an initializer, then
4908                 // the reference is OK.
4909                 if (!Resolve.isInitializer(env))
4910                     return;
4911 
4912                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
4913             }
4914         }
4915 
4916         /** Is the given symbol a static, non-constant field of an Enum?
4917          *  Note: enum literals should not be regarded as such
4918          */
4919         private boolean isStaticEnumField(VarSymbol v) {
4920             return Flags.isEnum(v.owner) &&
4921                    Flags.isStatic(v) &&
4922                    !Flags.isConstant(v) &&
4923                    v.name != names._class;
4924         }
4925 
4926     /**
4927      * Check that method arguments conform to its instantiation.
4928      **/
4929     public Type checkMethod(Type site,
4930                             final Symbol sym,
4931                             ResultInfo resultInfo,
4932                             Env<AttrContext> env,
4933                             final List<JCExpression> argtrees,
4934                             List<Type> argtypes,
4935                             List<Type> typeargtypes) {
4936         // Test (5): if symbol is an instance method of a raw type, issue
4937         // an unchecked warning if its argument types change under erasure.
4938         if ((sym.flags() & STATIC) == 0 &&
4939             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4940             Type s = types.asOuterSuper(site, sym.owner);
4941             if (s != null && s.isRaw() &&
4942                 !types.isSameTypes(sym.type.getParameterTypes(),
4943                                    sym.erasure(types).getParameterTypes())) {
4944                 chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedCallMbrOfRawType(sym, s));
4945             }
4946         }
4947 
4948         if (env.info.defaultSuperCallSite != null) {
4949             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
4950                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
4951                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
4952                 List<MethodSymbol> icand_sup =
4953                         types.interfaceCandidates(sup, (MethodSymbol)sym);
4954                 if (icand_sup.nonEmpty() &&
4955                         icand_sup.head != sym &&
4956                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
4957                     log.error(env.tree.pos(),
4958                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
4959                     break;
4960                 }
4961             }
4962             env.info.defaultSuperCallSite = null;
4963         }
4964 
4965         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
4966             JCMethodInvocation app = (JCMethodInvocation)env.tree;
4967             if (app.meth.hasTag(SELECT) &&
4968                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
4969                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
4970             }
4971         }
4972 
4973         // Compute the identifier's instantiated type.
4974         // For methods, we need to compute the instance type by
4975         // Resolve.instantiate from the symbol's type as well as
4976         // any type arguments and value arguments.
4977         Warner noteWarner = new Warner();
4978         try {
4979             Type owntype = rs.checkMethod(
4980                     env,
4981                     site,
4982                     sym,
4983                     resultInfo,
4984                     argtypes,
4985                     typeargtypes,
4986                     noteWarner);
4987 
4988             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
4989                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
4990 
4991             argtypes = argtypes.map(checkDeferredMap);
4992 
4993             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
4994                 chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedMethInvocationApplied(kindName(sym),
4995                         sym.name,
4996                         rs.methodArguments(sym.type.getParameterTypes()),
4997                         rs.methodArguments(argtypes.map(checkDeferredMap)),
4998                         kindName(sym.location()),
4999                         sym.location()));
5000                 if (resultInfo.pt != Infer.anyPoly ||
5001                         !owntype.hasTag(METHOD) ||
5002                         !owntype.isPartial()) {
5003                     //if this is not a partially inferred method type, erase return type. Otherwise,
5004                     //erasure is carried out in PartiallyInferredMethodType.check().
5005                     owntype = new MethodType(owntype.getParameterTypes(),
5006                             types.erasure(owntype.getReturnType()),
5007                             types.erasure(owntype.getThrownTypes()),
5008                             syms.methodClass);
5009                 }
5010             }
5011 
5012             PolyKind pkind = (sym.type.hasTag(FORALL) &&
5013                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
5014                  PolyKind.POLY : PolyKind.STANDALONE;
5015             TreeInfo.setPolyKind(env.tree, pkind);
5016 
5017             return (resultInfo.pt == Infer.anyPoly) ?
5018                     owntype :
5019                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
5020                             resultInfo.checkContext.inferenceContext());
5021         } catch (Infer.InferenceException ex) {
5022             //invalid target type - propagate exception outwards or report error
5023             //depending on the current check context
5024             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
5025             return types.createErrorType(site);
5026         } catch (Resolve.InapplicableMethodException ex) {
5027             final JCDiagnostic diag = ex.getDiagnostic();
5028             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
5029                 @Override
5030                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
5031                     return new Pair<>(sym, diag);
5032                 }
5033             };
5034             List<Type> argtypes2 = argtypes.map(
5035                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
5036             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
5037                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
5038             log.report(errDiag);
5039             return types.createErrorType(site);
5040         }
5041     }
5042 
5043     public void visitDefaultValue(JCDefaultValue tree) {
5044         if (!allowPrimitiveClasses) {
5045             log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(),
5046                     Feature.PRIMITIVE_CLASSES.error(sourceName));
5047         }
5048 
5049         // Attribute the qualifier expression, and determine its symbol (if any).
5050         Type site = attribTree(tree.clazz, env, new ResultInfo(KindSelector.TYP_PCK, Type.noType));
5051         if (!pkind().contains(KindSelector.TYP_PCK))
5052             site = capture(site); // Capture field access
5053         if (!allowPrimitiveClasses) {
5054             result = types.createErrorType(names._default, site.tsym, site);
5055         } else {
5056             Symbol sym = switch (site.getTag()) {
5057                 case WILDCARD -> throw new AssertionError(tree);
5058                 case PACKAGE -> {
5059                     log.error(tree.pos, Errors.CantResolveLocation(Kinds.KindName.CLASS, site.tsym.getQualifiedName(), null, null,
5060                             Fragments.Location(Kinds.typeKindName(env.enclClass.type), env.enclClass.type, null)));
5061                     yield syms.errSymbol;
5062                 }
5063                 case ERROR -> types.createErrorType(names._default, site.tsym, site).tsym;
5064                 default -> new VarSymbol(STATIC, names._default, site, site.tsym);
5065             };
5066 
5067             if (site.hasTag(TYPEVAR) && sym.kind != ERR) {
5068                 site = types.skipTypeVars(site, true);
5069             }
5070             result = checkId(tree, site, sym, env, resultInfo);
5071         }
5072     }
5073 
5074     public void visitLiteral(JCLiteral tree) {
5075         result = check(tree, litType(tree.typetag).constType(tree.value),
5076                 KindSelector.VAL, resultInfo);
5077     }
5078     //where
5079     /** Return the type of a literal with given type tag.
5080      */
5081     Type litType(TypeTag tag) {
5082         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
5083     }
5084 
5085     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5086         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5087     }
5088 
5089     public void visitTypeArray(JCArrayTypeTree tree) {
5090         Type etype = attribType(tree.elemtype, env);
5091         Type type = new ArrayType(etype, syms.arrayClass);
5092         result = check(tree, type, KindSelector.TYP, resultInfo);
5093     }
5094 
5095     /** Visitor method for parameterized types.
5096      *  Bound checking is left until later, since types are attributed
5097      *  before supertype structure is completely known
5098      */
5099     public void visitTypeApply(JCTypeApply tree) {
5100         Type owntype = types.createErrorType(tree.type);
5101 
5102         // Attribute functor part of application and make sure it's a class.
5103         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5104 
5105         // Attribute type parameters
5106         List<Type> actuals = attribTypes(tree.arguments, env);
5107 
5108         if (clazztype.hasTag(CLASS)) {
5109             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5110             if (actuals.isEmpty()) //diamond
5111                 actuals = formals;
5112 
5113             if (actuals.length() == formals.length()) {
5114                 List<Type> a = actuals;
5115                 List<Type> f = formals;
5116                 while (a.nonEmpty()) {
5117                     a.head = a.head.withTypeVar(f.head);
5118                     a = a.tail;
5119                     f = f.tail;
5120                 }
5121                 // Compute the proper generic outer
5122                 Type clazzOuter = clazztype.getEnclosingType();
5123                 if (clazzOuter.hasTag(CLASS)) {
5124                     Type site;
5125                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5126                     if (clazz.hasTag(IDENT)) {
5127                         site = env.enclClass.sym.type;
5128                     } else if (clazz.hasTag(SELECT)) {
5129                         site = ((JCFieldAccess) clazz).selected.type;
5130                     } else throw new AssertionError(""+tree);
5131                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5132                         if (site.hasTag(CLASS))
5133                             site = types.asOuterSuper(site, clazzOuter.tsym);
5134                         if (site == null)
5135                             site = types.erasure(clazzOuter);
5136                         clazzOuter = site;
5137                     }
5138                 }
5139                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5140                                         clazztype.getMetadata(), clazztype.getFlavor());
5141             } else {
5142                 if (formals.length() != 0) {
5143                     log.error(tree.pos(),
5144                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5145                 } else {
5146                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5147                 }
5148                 owntype = types.createErrorType(tree.type);
5149             }
5150         }
5151         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5152     }
5153 
5154     public void visitTypeUnion(JCTypeUnion tree) {
5155         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5156         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5157         for (JCExpression typeTree : tree.alternatives) {
5158             Type ctype = attribType(typeTree, env);
5159             ctype = chk.checkType(typeTree.pos(),
5160                           chk.checkClassType(typeTree.pos(), ctype),
5161                           syms.throwableType);
5162             if (!ctype.isErroneous()) {
5163                 //check that alternatives of a union type are pairwise
5164                 //unrelated w.r.t. subtyping
5165                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5166                     for (Type t : multicatchTypes) {
5167                         boolean sub = types.isSubtype(ctype, t);
5168                         boolean sup = types.isSubtype(t, ctype);
5169                         if (sub || sup) {
5170                             //assume 'a' <: 'b'
5171                             Type a = sub ? ctype : t;
5172                             Type b = sub ? t : ctype;
5173                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5174                         }
5175                     }
5176                 }
5177                 multicatchTypes.append(ctype);
5178                 if (all_multicatchTypes != null)
5179                     all_multicatchTypes.append(ctype);
5180             } else {
5181                 if (all_multicatchTypes == null) {
5182                     all_multicatchTypes = new ListBuffer<>();
5183                     all_multicatchTypes.appendList(multicatchTypes);
5184                 }
5185                 all_multicatchTypes.append(ctype);
5186             }
5187         }
5188         Type t = check(tree, types.lub(multicatchTypes.toList()),
5189                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5190         if (t.hasTag(CLASS)) {
5191             List<Type> alternatives =
5192                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5193             t = new UnionClassType((ClassType) t, alternatives);
5194         }
5195         tree.type = result = t;
5196     }
5197 
5198     public void visitTypeIntersection(JCTypeIntersection tree) {
5199         attribTypes(tree.bounds, env);
5200         tree.type = result = checkIntersection(tree, tree.bounds);
5201     }
5202 
5203     public void visitTypeParameter(JCTypeParameter tree) {
5204         TypeVar typeVar = (TypeVar) tree.type;
5205 
5206         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5207             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5208         }
5209 
5210         if (!typeVar.getUpperBound().isErroneous()) {
5211             //fixup type-parameter bound computed in 'attribTypeVariables'
5212             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5213         }
5214     }
5215 
5216     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5217         Set<Type> boundSet = new HashSet<>();
5218         if (bounds.nonEmpty()) {
5219             // accept class or interface or typevar as first bound.
5220             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5221             boundSet.add(types.erasure(bounds.head.type));
5222             if (bounds.head.type.isErroneous()) {
5223                 return bounds.head.type;
5224             }
5225             else if (bounds.head.type.hasTag(TYPEVAR)) {
5226                 // if first bound was a typevar, do not accept further bounds.
5227                 if (bounds.tail.nonEmpty()) {
5228                     log.error(bounds.tail.head.pos(),
5229                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5230                     return bounds.head.type;
5231                 }
5232             } else {
5233                 // if first bound was a class or interface, accept only interfaces
5234                 // as further bounds.
5235                 for (JCExpression bound : bounds.tail) {
5236                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5237                     if (bound.type.isErroneous()) {
5238                         bounds = List.of(bound);
5239                     }
5240                     else if (bound.type.hasTag(CLASS)) {
5241                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5242                     }
5243                 }
5244             }
5245         }
5246 
5247         if (bounds.length() == 0) {
5248             return syms.objectType;
5249         } else if (bounds.length() == 1) {
5250             return bounds.head.type;
5251         } else {
5252             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5253             // ... the variable's bound is a class type flagged COMPOUND
5254             // (see comment for TypeVar.bound).
5255             // In this case, generate a class tree that represents the
5256             // bound class, ...
5257             JCExpression extending;
5258             List<JCExpression> implementing;
5259             if (!bounds.head.type.isInterface()) {
5260                 extending = bounds.head;
5261                 implementing = bounds.tail;
5262             } else {
5263                 extending = null;
5264                 implementing = bounds;
5265             }
5266             JCClassDecl cd = make.at(tree).ClassDef(
5267                 make.Modifiers(PUBLIC | ABSTRACT | (extending != null && TreeInfo.symbol(extending).isPrimitiveClass() ? PRIMITIVE_CLASS : 0)),
5268                 names.empty, List.nil(),
5269                 extending, implementing, List.nil());
5270 
5271             ClassSymbol c = (ClassSymbol)owntype.tsym;
5272             Assert.check((c.flags() & COMPOUND) != 0);
5273             cd.sym = c;
5274             c.sourcefile = env.toplevel.sourcefile;
5275 
5276             // ... and attribute the bound class
5277             c.flags_field |= UNATTRIBUTED;
5278             Env<AttrContext> cenv = enter.classEnv(cd, env);
5279             typeEnvs.put(c, cenv);
5280             attribClass(c);
5281             return owntype;
5282         }
5283     }
5284 
5285     public void visitWildcard(JCWildcard tree) {
5286         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5287         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5288             ? syms.objectType
5289             : attribType(tree.inner, env);
5290         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type, false),
5291                                               tree.kind.kind,
5292                                               syms.boundClass),
5293                 KindSelector.TYP, resultInfo);
5294     }
5295 
5296     public void visitAnnotation(JCAnnotation tree) {
5297         Assert.error("should be handled in annotate");
5298     }
5299 
5300     @Override
5301     public void visitModifiers(JCModifiers tree) {
5302         //error recovery only:
5303         Assert.check(resultInfo.pkind == KindSelector.ERR);
5304 
5305         attribAnnotationTypes(tree.annotations, env);
5306     }
5307 
5308     public void visitAnnotatedType(JCAnnotatedType tree) {
5309         attribAnnotationTypes(tree.annotations, env);
5310         Type underlyingType = attribType(tree.underlyingType, env);
5311         Type annotatedType = underlyingType.annotatedType(Annotations.TO_BE_SET);
5312 
5313         if (!env.info.isNewClass)
5314             annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5315         result = tree.type = annotatedType;
5316     }
5317 
5318     public void visitErroneous(JCErroneous tree) {
5319         if (tree.errs != null) {
5320             Env<AttrContext> errEnv = env.dup(env.tree);
5321             errEnv.info.returnResult = unknownExprInfo;
5322             for (JCTree err : tree.errs)
5323                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5324         }
5325         result = tree.type = syms.errType;
5326     }
5327 
5328     /** Default visitor method for all other trees.
5329      */
5330     public void visitTree(JCTree tree) {
5331         throw new AssertionError();
5332     }
5333 
5334     /**
5335      * Attribute an env for either a top level tree or class or module declaration.
5336      */
5337     public void attrib(Env<AttrContext> env) {
5338         switch (env.tree.getTag()) {
5339             case MODULEDEF:
5340                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5341                 break;
5342             case PACKAGEDEF:
5343                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5344                 break;
5345             default:
5346                 attribClass(env.tree.pos(), env.enclClass.sym);
5347         }
5348     }
5349 
5350     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5351         try {
5352             annotate.flush();
5353             attribPackage(p);
5354         } catch (CompletionFailure ex) {
5355             chk.completionError(pos, ex);
5356         }
5357     }
5358 
5359     void attribPackage(PackageSymbol p) {
5360         attribWithLint(p,
5361                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5362     }
5363 
5364     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5365         try {
5366             annotate.flush();
5367             attribModule(m);
5368         } catch (CompletionFailure ex) {
5369             chk.completionError(pos, ex);
5370         }
5371     }
5372 
5373     void attribModule(ModuleSymbol m) {
5374         attribWithLint(m, env -> attribStat(env.tree, env));
5375     }
5376 
5377     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5378         Env<AttrContext> env = typeEnvs.get(sym);
5379 
5380         Env<AttrContext> lintEnv = env;
5381         while (lintEnv.info.lint == null)
5382             lintEnv = lintEnv.next;
5383 
5384         Lint lint = lintEnv.info.lint.augment(sym);
5385 
5386         Lint prevLint = chk.setLint(lint);
5387         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5388 
5389         try {
5390             deferredLintHandler.flush(env.tree.pos());
5391             attrib.accept(env);
5392         } finally {
5393             log.useSource(prev);
5394             chk.setLint(prevLint);
5395         }
5396     }
5397 
5398     /** Main method: attribute class definition associated with given class symbol.
5399      *  reporting completion failures at the given position.
5400      *  @param pos The source position at which completion errors are to be
5401      *             reported.
5402      *  @param c   The class symbol whose definition will be attributed.
5403      */
5404     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5405         try {
5406             annotate.flush();
5407             attribClass(c);
5408             if (allowPrimitiveClasses && c.type.isPrimitiveClass()) {
5409                 final Env<AttrContext> env = typeEnvs.get(c);
5410                 if (env != null && env.tree != null && env.tree.hasTag(CLASSDEF))
5411                     chk.checkNonCyclicMembership((JCClassDecl)env.tree);
5412             }
5413         } catch (CompletionFailure ex) {
5414             chk.completionError(pos, ex);
5415         }
5416     }
5417 
5418     /** Attribute class definition associated with given class symbol.
5419      *  @param c   The class symbol whose definition will be attributed.
5420      */
5421     void attribClass(ClassSymbol c) throws CompletionFailure {
5422         if (c.type.hasTag(ERROR)) return;
5423 
5424         // Check for cycles in the inheritance graph, which can arise from
5425         // ill-formed class files.
5426         chk.checkNonCyclic(null, c.type);
5427 
5428         Type st = types.supertype(c.type);
5429         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5430             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0) {
5431             // First, attribute superclass.
5432             if (st.hasTag(CLASS))
5433                 attribClass((ClassSymbol)st.tsym);
5434 
5435             // Next attribute owner, if it is a class.
5436             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5437                 attribClass((ClassSymbol)c.owner);
5438 
5439             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5440         }
5441 
5442         // The previous operations might have attributed the current class
5443         // if there was a cycle. So we test first whether the class is still
5444         // UNATTRIBUTED.
5445         if ((c.flags_field & UNATTRIBUTED) != 0) {
5446             c.flags_field &= ~UNATTRIBUTED;
5447 
5448             // Get environment current at the point of class definition.
5449             Env<AttrContext> env = typeEnvs.get(c);
5450 
5451             if (c.isSealed() &&
5452                     !c.isEnum() &&
5453                     !c.isPermittedExplicit &&
5454                     c.permitted.isEmpty()) {
5455                 log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5456             }
5457 
5458             if (c.isSealed()) {
5459                 Set<Symbol> permittedTypes = new HashSet<>();
5460                 boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5461                 for (Symbol subTypeSym : c.permitted) {
5462                     boolean isTypeVar = false;
5463                     if (subTypeSym.type.getTag() == TYPEVAR) {
5464                         isTypeVar = true; //error recovery
5465                         log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5466                                 Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subTypeSym.type)));
5467                     }
5468                     if (subTypeSym.isAnonymous() && !c.isEnum()) {
5469                         log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5470                     }
5471                     if (permittedTypes.contains(subTypeSym)) {
5472                         DiagnosticPosition pos =
5473                                 env.enclClass.permitting.stream()
5474                                         .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subTypeSym, permittedExpr, true) != null)
5475                                         .limit(2).collect(List.collector()).get(1);
5476                         log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subTypeSym.type)));
5477                     } else {
5478                         permittedTypes.add(subTypeSym);
5479                     }
5480                     if (sealedInUnnamed) {
5481                         if (subTypeSym.packge() != c.packge()) {
5482                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5483                                     Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5484                             );
5485                         }
5486                     } else if (subTypeSym.packge().modle != c.packge().modle) {
5487                         log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5488                                 Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5489                         );
5490                     }
5491                     if (subTypeSym == c.type.tsym || types.isSuperType(subTypeSym.type, c.type)) {
5492                         log.error(TreeInfo.diagnosticPositionFor(subTypeSym, ((JCClassDecl)env.tree).permitting),
5493                                 Errors.InvalidPermitsClause(
5494                                         subTypeSym == c.type.tsym ?
5495                                                 Fragments.MustNotBeSameClass :
5496                                                 Fragments.MustNotBeSupertype(subTypeSym.type)
5497                                 )
5498                         );
5499                     } else if (!isTypeVar) {
5500                         boolean thisIsASuper = types.directSupertypes(subTypeSym.type)
5501                                                     .stream()
5502                                                     .anyMatch(d -> d.tsym == c);
5503                         if (!thisIsASuper) {
5504                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5505                                     Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subTypeSym.type)));
5506                         }
5507                     }
5508                 }
5509             }
5510 
5511             List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5512                                                   .stream()
5513                                                   .filter(s -> s.tsym.isSealed())
5514                                                   .map(s -> (ClassSymbol) s.tsym)
5515                                                   .collect(List.collector());
5516 
5517             if (sealedSupers.isEmpty()) {
5518                 if ((c.flags_field & Flags.NON_SEALED) != 0) {
5519                     boolean hasErrorSuper = false;
5520 
5521                     hasErrorSuper |= types.directSupertypes(c.type)
5522                                           .stream()
5523                                           .anyMatch(s -> s.tsym.kind == Kind.ERR);
5524 
5525                     ClassType ct = (ClassType) c.type;
5526 
5527                     hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5528 
5529                     if (!hasErrorSuper) {
5530                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5531                     }
5532                 }
5533             } else if ((c.flags_field & Flags.COMPOUND) == 0) {
5534                 if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5535                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5536                 }
5537 
5538                 if (!c.type.isCompound()) {
5539                     for (ClassSymbol supertypeSym : sealedSupers) {
5540                         if (!supertypeSym.permitted.contains(c.type.tsym)) {
5541                             log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5542                         }
5543                     }
5544                     if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5545                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5546                                 c.isInterface() ?
5547                                         Errors.NonSealedOrSealedExpected :
5548                                         Errors.NonSealedSealedOrFinalExpected);
5549                     }
5550                 }
5551             }
5552 
5553             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5554             // because the annotations were not available at the time the env was created. Therefore,
5555             // we look up the environment chain for the first enclosing environment for which the
5556             // lint value is set. Typically, this is the parent env, but might be further if there
5557             // are any envs created as a result of TypeParameter nodes.
5558             Env<AttrContext> lintEnv = env;
5559             while (lintEnv.info.lint == null)
5560                 lintEnv = lintEnv.next;
5561 
5562             // Having found the enclosing lint value, we can initialize the lint value for this class
5563             env.info.lint = lintEnv.info.lint.augment(c);
5564 
5565             Lint prevLint = chk.setLint(env.info.lint);
5566             JavaFileObject prev = log.useSource(c.sourcefile);
5567             ResultInfo prevReturnRes = env.info.returnResult;
5568 
5569             try {
5570                 deferredLintHandler.flush(env.tree);
5571                 env.info.returnResult = null;
5572                 // java.lang.Enum may not be subclassed by a non-enum
5573                 if (st.tsym == syms.enumSym &&
5574                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5575                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5576 
5577                 // Enums may not be extended by source-level classes
5578                 if (st.tsym != null &&
5579                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5580                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5581                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5582                 }
5583 
5584                 if (rs.isSerializable(c.type)) {
5585                     env.info.isSerializable = true;
5586                 }
5587 
5588                 if (c.isValueClass()) {
5589                     Assert.check(env.tree.hasTag(CLASSDEF));
5590                     chk.checkConstraintsOfValueClass(env.tree.pos(), c);
5591                 }
5592 
5593                 attribClassBody(env, c);
5594 
5595                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5596                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5597                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5598                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5599             } finally {
5600                 env.info.returnResult = prevReturnRes;
5601                 log.useSource(prev);
5602                 chk.setLint(prevLint);
5603             }
5604 
5605         }
5606     }
5607 
5608     public void visitImport(JCImport tree) {
5609         // nothing to do
5610     }
5611 
5612     public void visitModuleDef(JCModuleDecl tree) {
5613         tree.sym.completeUsesProvides();
5614         ModuleSymbol msym = tree.sym;
5615         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5616         Lint prevLint = chk.setLint(lint);
5617         chk.checkModuleName(tree);
5618         chk.checkDeprecatedAnnotation(tree, msym);
5619 
5620         try {
5621             deferredLintHandler.flush(tree.pos());
5622         } finally {
5623             chk.setLint(prevLint);
5624         }
5625     }
5626 
5627     /** Finish the attribution of a class. */
5628     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5629         JCClassDecl tree = (JCClassDecl)env.tree;
5630         Assert.check(c == tree.sym);
5631 
5632         // Validate type parameters, supertype and interfaces.
5633         attribStats(tree.typarams, env);
5634         if (!c.isAnonymous()) {
5635             //already checked if anonymous
5636             chk.validate(tree.typarams, env);
5637             chk.validate(tree.extending, env);
5638             chk.validate(tree.implementing, env);
5639         }
5640 
5641         c.markAbstractIfNeeded(types);
5642 
5643         // If this is a non-abstract class, check that it has no abstract
5644         // methods or unimplemented methods of an implemented interface.
5645         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
5646             chk.checkAllDefined(tree.pos(), c);
5647         }
5648 
5649         if ((c.flags() & ANNOTATION) != 0) {
5650             if (tree.implementing.nonEmpty())
5651                 log.error(tree.implementing.head.pos(),
5652                           Errors.CantExtendIntfAnnotation);
5653             if (tree.typarams.nonEmpty()) {
5654                 log.error(tree.typarams.head.pos(),
5655                           Errors.IntfAnnotationCantHaveTypeParams(c));
5656             }
5657 
5658             // If this annotation type has a @Repeatable, validate
5659             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
5660             // If this annotation type has a @Repeatable, validate
5661             if (repeatable != null) {
5662                 // get diagnostic position for error reporting
5663                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
5664                 Assert.checkNonNull(cbPos);
5665 
5666                 chk.validateRepeatable(c, repeatable, cbPos);
5667             }
5668         } else {
5669             // Check that all extended classes and interfaces
5670             // are compatible (i.e. no two define methods with same arguments
5671             // yet different return types).  (JLS 8.4.8.3)
5672             chk.checkCompatibleSupertypes(tree.pos(), c.type);
5673             chk.checkDefaultMethodClashes(tree.pos(), c.type);
5674         }
5675 
5676         // Check that class does not import the same parameterized interface
5677         // with two different argument lists.
5678         chk.checkClassBounds(tree.pos(), c.type);
5679 
5680         tree.type = c.type;
5681 
5682         for (List<JCTypeParameter> l = tree.typarams;
5683              l.nonEmpty(); l = l.tail) {
5684              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
5685         }
5686 
5687         // Check that a generic class doesn't extend Throwable
5688         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
5689             log.error(tree.extending.pos(), Errors.GenericThrowable);
5690 
5691         // Check that all methods which implement some
5692         // method conform to the method they implement.
5693         chk.checkImplementations(tree);
5694 
5695         //check that a resource implementing AutoCloseable cannot throw InterruptedException
5696         checkAutoCloseable(tree.pos(), env, c.type);
5697 
5698         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
5699             // Attribute declaration
5700             attribStat(l.head, env);
5701             // Check that declarations in inner classes are not static (JLS 8.1.2)
5702             // Make an exception for static constants.
5703             if (!allowRecords &&
5704                     c.owner.kind != PCK &&
5705                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
5706                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
5707                 VarSymbol sym = null;
5708                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
5709                 if (sym == null ||
5710                         sym.kind != VAR ||
5711                         sym.getConstValue() == null)
5712                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
5713             }
5714         }
5715 
5716         // Check for cycles among non-initial constructors.
5717         chk.checkCyclicConstructors(tree);
5718 
5719         // Check for cycles among annotation elements.
5720         chk.checkNonCyclicElements(tree);
5721 
5722         // Check for proper use of serialVersionUID and other
5723         // serialization-related fields and methods
5724         if (env.info.lint.isEnabled(LintCategory.SERIAL)
5725                 && rs.isSerializable(c.type)
5726                 && !c.isAnonymous()) {
5727             chk.checkSerialStructure(tree, c);
5728         }
5729         // Correctly organize the positions of the type annotations
5730         typeAnnotations.organizeTypeAnnotationsBodies(tree);
5731 
5732         // Check type annotations applicability rules
5733         validateTypeAnnotations(tree, false);
5734     }
5735         // where
5736         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
5737         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
5738             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
5739                 if (types.isSameType(al.head.annotationType.type, t))
5740                     return al.head.pos();
5741             }
5742 
5743             return null;
5744         }
5745 
5746     private Type capture(Type type) {
5747         return types.capture(type);
5748     }
5749 
5750     private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
5751         if (type.isErroneous()) {
5752             tree.vartype = make.at(Position.NOPOS).Erroneous();
5753         } else {
5754             tree.vartype = make.at(Position.NOPOS).Type(type);
5755         }
5756     }
5757 
5758     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
5759         tree.accept(new TypeAnnotationsValidator(sigOnly));
5760     }
5761     //where
5762     private final class TypeAnnotationsValidator extends TreeScanner {
5763 
5764         private final boolean sigOnly;
5765         public TypeAnnotationsValidator(boolean sigOnly) {
5766             this.sigOnly = sigOnly;
5767         }
5768 
5769         public void visitAnnotation(JCAnnotation tree) {
5770             chk.validateTypeAnnotation(tree, false);
5771             super.visitAnnotation(tree);
5772         }
5773         public void visitAnnotatedType(JCAnnotatedType tree) {
5774             if (!tree.underlyingType.type.isErroneous()) {
5775                 super.visitAnnotatedType(tree);
5776             }
5777         }
5778         public void visitTypeParameter(JCTypeParameter tree) {
5779             chk.validateTypeAnnotations(tree.annotations, true);
5780             scan(tree.bounds);
5781             // Don't call super.
5782             // This is needed because above we call validateTypeAnnotation with
5783             // false, which would forbid annotations on type parameters.
5784             // super.visitTypeParameter(tree);
5785         }
5786         public void visitMethodDef(JCMethodDecl tree) {
5787             if (tree.recvparam != null &&
5788                     !tree.recvparam.vartype.type.isErroneous()) {
5789                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
5790             }
5791             if (tree.restype != null && tree.restype.type != null) {
5792                 validateAnnotatedType(tree.restype, tree.restype.type);
5793             }
5794             if (sigOnly) {
5795                 scan(tree.mods);
5796                 scan(tree.restype);
5797                 scan(tree.typarams);
5798                 scan(tree.recvparam);
5799                 scan(tree.params);
5800                 scan(tree.thrown);
5801             } else {
5802                 scan(tree.defaultValue);
5803                 scan(tree.body);
5804             }
5805         }
5806         public void visitVarDef(final JCVariableDecl tree) {
5807             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
5808             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
5809                 validateAnnotatedType(tree.vartype, tree.sym.type);
5810             scan(tree.mods);
5811             scan(tree.vartype);
5812             if (!sigOnly) {
5813                 scan(tree.init);
5814             }
5815         }
5816         public void visitTypeCast(JCTypeCast tree) {
5817             if (tree.clazz != null && tree.clazz.type != null)
5818                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5819             super.visitTypeCast(tree);
5820         }
5821         public void visitTypeTest(JCInstanceOf tree) {
5822             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
5823                 validateAnnotatedType(tree.pattern, tree.pattern.type);
5824             super.visitTypeTest(tree);
5825         }
5826         public void visitNewClass(JCNewClass tree) {
5827             if (tree.clazz != null && tree.clazz.type != null) {
5828                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
5829                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
5830                             tree.clazz.type.tsym);
5831                 }
5832                 if (tree.def != null) {
5833                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
5834                 }
5835 
5836                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5837             }
5838             super.visitNewClass(tree);
5839         }
5840         public void visitNewArray(JCNewArray tree) {
5841             if (tree.elemtype != null && tree.elemtype.type != null) {
5842                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
5843                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
5844                             tree.elemtype.type.tsym);
5845                 }
5846                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
5847             }
5848             super.visitNewArray(tree);
5849         }
5850         public void visitClassDef(JCClassDecl tree) {
5851             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
5852             if (sigOnly) {
5853                 scan(tree.mods);
5854                 scan(tree.typarams);
5855                 scan(tree.extending);
5856                 scan(tree.implementing);
5857             }
5858             for (JCTree member : tree.defs) {
5859                 if (member.hasTag(Tag.CLASSDEF)) {
5860                     continue;
5861                 }
5862                 scan(member);
5863             }
5864         }
5865         public void visitBlock(JCBlock tree) {
5866             if (!sigOnly) {
5867                 scan(tree.stats);
5868             }
5869         }
5870 
5871         /* I would want to model this after
5872          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
5873          * and override visitSelect and visitTypeApply.
5874          * However, we only set the annotated type in the top-level type
5875          * of the symbol.
5876          * Therefore, we need to override each individual location where a type
5877          * can occur.
5878          */
5879         private void validateAnnotatedType(final JCTree errtree, final Type type) {
5880             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
5881 
5882             if (type.isPrimitiveOrVoid()) {
5883                 return;
5884             }
5885 
5886             JCTree enclTr = errtree;
5887             Type enclTy = type;
5888 
5889             boolean repeat = true;
5890             while (repeat) {
5891                 if (enclTr.hasTag(TYPEAPPLY)) {
5892                     List<Type> tyargs = enclTy.getTypeArguments();
5893                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
5894                     if (trargs.length() > 0) {
5895                         // Nothing to do for diamonds
5896                         if (tyargs.length() == trargs.length()) {
5897                             for (int i = 0; i < tyargs.length(); ++i) {
5898                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
5899                             }
5900                         }
5901                         // If the lengths don't match, it's either a diamond
5902                         // or some nested type that redundantly provides
5903                         // type arguments in the tree.
5904                     }
5905 
5906                     // Look at the clazz part of a generic type
5907                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
5908                 }
5909 
5910                 if (enclTr.hasTag(SELECT)) {
5911                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
5912                     if (enclTy != null &&
5913                             !enclTy.hasTag(NONE)) {
5914                         enclTy = enclTy.getEnclosingType();
5915                     }
5916                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
5917                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
5918                     if (enclTy == null || enclTy.hasTag(NONE)) {
5919                         if (at.getAnnotations().size() == 1) {
5920                             log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping1(at.getAnnotations().head.attribute));
5921                         } else {
5922                             ListBuffer<Attribute.Compound> comps = new ListBuffer<>();
5923                             for (JCAnnotation an : at.getAnnotations()) {
5924                                 comps.add(an.attribute);
5925                             }
5926                             log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping(comps.toList()));
5927                         }
5928                         repeat = false;
5929                     }
5930                     enclTr = at.underlyingType;
5931                     // enclTy doesn't need to be changed
5932                 } else if (enclTr.hasTag(IDENT)) {
5933                     repeat = false;
5934                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
5935                     JCWildcard wc = (JCWildcard) enclTr;
5936                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
5937                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
5938                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
5939                     } else {
5940                         // Nothing to do for UNBOUND
5941                     }
5942                     repeat = false;
5943                 } else if (enclTr.hasTag(TYPEARRAY)) {
5944                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
5945                     validateAnnotatedType(art.getType(), art.elemtype.type);
5946                     repeat = false;
5947                 } else if (enclTr.hasTag(TYPEUNION)) {
5948                     JCTypeUnion ut = (JCTypeUnion) enclTr;
5949                     for (JCTree t : ut.getTypeAlternatives()) {
5950                         validateAnnotatedType(t, t.type);
5951                     }
5952                     repeat = false;
5953                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
5954                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
5955                     for (JCTree t : it.getBounds()) {
5956                         validateAnnotatedType(t, t.type);
5957                     }
5958                     repeat = false;
5959                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
5960                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
5961                     repeat = false;
5962                 } else {
5963                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
5964                             " within: "+ errtree + " with kind: " + errtree.getKind());
5965                 }
5966             }
5967         }
5968 
5969         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
5970                 Symbol sym) {
5971             // Ensure that no declaration annotations are present.
5972             // Note that a tree type might be an AnnotatedType with
5973             // empty annotations, if only declaration annotations were given.
5974             // This method will raise an error for such a type.
5975             for (JCAnnotation ai : annotations) {
5976                 if (!ai.type.isErroneous() &&
5977                         typeAnnotations.annotationTargetType(ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
5978                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
5979                 }
5980             }
5981         }
5982     }
5983 
5984     // <editor-fold desc="post-attribution visitor">
5985 
5986     /**
5987      * Handle missing types/symbols in an AST. This routine is useful when
5988      * the compiler has encountered some errors (which might have ended up
5989      * terminating attribution abruptly); if the compiler is used in fail-over
5990      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
5991      * prevents NPE to be propagated during subsequent compilation steps.
5992      */
5993     public void postAttr(JCTree tree) {
5994         new PostAttrAnalyzer().scan(tree);
5995     }
5996 
5997     class PostAttrAnalyzer extends TreeScanner {
5998 
5999         private void initTypeIfNeeded(JCTree that) {
6000             if (that.type == null) {
6001                 if (that.hasTag(METHODDEF)) {
6002                     that.type = dummyMethodType((JCMethodDecl)that);
6003                 } else {
6004                     that.type = syms.unknownType;
6005                 }
6006             }
6007         }
6008 
6009         /* Construct a dummy method type. If we have a method declaration,
6010          * and the declared return type is void, then use that return type
6011          * instead of UNKNOWN to avoid spurious error messages in lambda
6012          * bodies (see:JDK-8041704).
6013          */
6014         private Type dummyMethodType(JCMethodDecl md) {
6015             Type restype = syms.unknownType;
6016             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
6017                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
6018                 if (prim.typetag == VOID)
6019                     restype = syms.voidType;
6020             }
6021             return new MethodType(List.nil(), restype,
6022                                   List.nil(), syms.methodClass);
6023         }
6024         private Type dummyMethodType() {
6025             return dummyMethodType(null);
6026         }
6027 
6028         @Override
6029         public void scan(JCTree tree) {
6030             if (tree == null) return;
6031             if (tree instanceof JCExpression) {
6032                 initTypeIfNeeded(tree);
6033             }
6034             super.scan(tree);
6035         }
6036 
6037         @Override
6038         public void visitIdent(JCIdent that) {
6039             if (that.sym == null) {
6040                 that.sym = syms.unknownSymbol;
6041             }
6042         }
6043 
6044         @Override
6045         public void visitSelect(JCFieldAccess that) {
6046             if (that.sym == null) {
6047                 that.sym = syms.unknownSymbol;
6048             }
6049             super.visitSelect(that);
6050         }
6051 
6052         @Override
6053         public void visitClassDef(JCClassDecl that) {
6054             initTypeIfNeeded(that);
6055             if (that.sym == null) {
6056                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
6057             }
6058             super.visitClassDef(that);
6059         }
6060 
6061         @Override
6062         public void visitMethodDef(JCMethodDecl that) {
6063             initTypeIfNeeded(that);
6064             if (that.sym == null) {
6065                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
6066             }
6067             super.visitMethodDef(that);
6068         }
6069 
6070         @Override
6071         public void visitVarDef(JCVariableDecl that) {
6072             initTypeIfNeeded(that);
6073             if (that.sym == null) {
6074                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
6075                 that.sym.adr = 0;
6076             }
6077             if (that.vartype == null) {
6078                 that.vartype = make.at(Position.NOPOS).Erroneous();
6079             }
6080             super.visitVarDef(that);
6081         }
6082 
6083         @Override
6084         public void visitBindingPattern(JCBindingPattern that) {
6085             initTypeIfNeeded(that);
6086             initTypeIfNeeded(that.var);
6087             if (that.var.sym == null) {
6088                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6089                 that.var.sym.adr = 0;
6090             }
6091             super.visitBindingPattern(that);
6092         }
6093 
6094         @Override
6095         public void visitNewClass(JCNewClass that) {
6096             if (that.constructor == null) {
6097                 that.constructor = new MethodSymbol(0, names.init,
6098                         dummyMethodType(), syms.noSymbol);
6099             }
6100             if (that.constructorType == null) {
6101                 that.constructorType = syms.unknownType;
6102             }
6103             super.visitNewClass(that);
6104         }
6105 
6106         @Override
6107         public void visitAssignop(JCAssignOp that) {
6108             if (that.operator == null) {
6109                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6110                         -1, syms.noSymbol);
6111             }
6112             super.visitAssignop(that);
6113         }
6114 
6115         @Override
6116         public void visitBinary(JCBinary that) {
6117             if (that.operator == null) {
6118                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6119                         -1, syms.noSymbol);
6120             }
6121             super.visitBinary(that);
6122         }
6123 
6124         @Override
6125         public void visitUnary(JCUnary that) {
6126             if (that.operator == null) {
6127                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6128                         -1, syms.noSymbol);
6129             }
6130             super.visitUnary(that);
6131         }
6132 
6133         @Override
6134         public void visitReference(JCMemberReference that) {
6135             super.visitReference(that);
6136             if (that.sym == null) {
6137                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6138                         syms.noSymbol);
6139             }
6140         }
6141     }
6142     // </editor-fold>
6143 
6144     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6145         new TreeScanner() {
6146             Symbol packge = pkg;
6147             @Override
6148             public void visitIdent(JCIdent that) {
6149                 that.sym = packge;
6150             }
6151 
6152             @Override
6153             public void visitSelect(JCFieldAccess that) {
6154                 that.sym = packge;
6155                 packge = packge.owner;
6156                 super.visitSelect(that);
6157             }
6158         }.scan(pid);
6159     }
6160 
6161 }