1 /*
   2  * Copyright (c) 1999, 2025, 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.function.Function;
  32 import java.util.stream.Stream;
  33 
  34 import javax.lang.model.element.ElementKind;
  35 import javax.tools.JavaFileObject;
  36 
  37 import com.sun.source.tree.CaseTree;
  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.LintMapper;
  46 import com.sun.tools.javac.code.Scope.WriteableScope;
  47 import com.sun.tools.javac.code.Source.Feature;
  48 import com.sun.tools.javac.code.Symbol.*;
  49 import com.sun.tools.javac.code.Type.*;
  50 import com.sun.tools.javac.code.Types.FunctionDescriptorLookupError;
  51 import com.sun.tools.javac.comp.ArgumentAttr.LocalCacheContext;
  52 import com.sun.tools.javac.comp.Check.CheckContext;
  53 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
  54 import com.sun.tools.javac.comp.MatchBindingsComputer.MatchBindings;
  55 import com.sun.tools.javac.jvm.*;
  56 
  57 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
  58 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
  59 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
  60 
  61 import com.sun.tools.javac.resources.CompilerProperties.Errors;
  62 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  63 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings;
  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 
  85 /** This is the main context-dependent analysis phase in GJC. It
  86  *  encompasses name resolution, type checking and constant folding as
  87  *  subtasks. Some subtasks involve auxiliary classes.
  88  *  @see Check
  89  *  @see Resolve
  90  *  @see ConstFold
  91  *  @see Infer
  92  *
  93  *  <p><b>This is NOT part of any supported API.
  94  *  If you write code that depends on this, you do so at your own risk.
  95  *  This code and its internal interfaces are subject to change or
  96  *  deletion without notice.</b>
  97  */
  98 public class Attr extends JCTree.Visitor {
  99     protected static final Context.Key<Attr> attrKey = new Context.Key<>();
 100 
 101     final Names names;
 102     final Log log;
 103     final LintMapper lintMapper;
 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 TypeEnvs typeEnvs;
 123     final Dependencies dependencies;
 124     final Annotate annotate;
 125     final ArgumentAttr argumentAttr;
 126     final MatchBindingsComputer matchBindingsComputer;
 127     final AttrRecover attrRecover;
 128 
 129     public static Attr instance(Context context) {
 130         Attr instance = context.get(attrKey);
 131         if (instance == null)
 132             instance = new Attr(context);
 133         return instance;
 134     }
 135 
 136     @SuppressWarnings("this-escape")
 137     protected Attr(Context context) {
 138         context.put(attrKey, this);
 139 
 140         names = Names.instance(context);
 141         log = Log.instance(context);
 142         lintMapper = LintMapper.instance(context);
 143         syms = Symtab.instance(context);
 144         rs = Resolve.instance(context);
 145         operators = Operators.instance(context);
 146         chk = Check.instance(context);
 147         flow = Flow.instance(context);
 148         memberEnter = MemberEnter.instance(context);
 149         typeEnter = TypeEnter.instance(context);
 150         make = TreeMaker.instance(context);
 151         enter = Enter.instance(context);
 152         infer = Infer.instance(context);
 153         analyzer = Analyzer.instance(context);
 154         deferredAttr = DeferredAttr.instance(context);
 155         cfolder = ConstFold.instance(context);
 156         target = Target.instance(context);
 157         types = Types.instance(context);
 158         preview = Preview.instance(context);
 159         diags = JCDiagnostic.Factory.instance(context);
 160         annotate = Annotate.instance(context);
 161         typeAnnotations = TypeAnnotations.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         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 172         allowRecords = Feature.RECORDS.allowedInSource(source);
 173         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 174                              Feature.PATTERN_SWITCH.allowedInSource(source);
 175         allowUnconditionalPatternsInstanceOf =
 176                              Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 177         sourceName = source.name;
 178         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 179 
 180         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 181         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 182         unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
 183         methodAttrInfo = new MethodAttrInfo();
 184         unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
 185         unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
 186         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
 187         initBlockType = new MethodType(List.nil(), syms.voidType, List.nil(), syms.methodClass);
 188     }
 189 
 190     /** Switch: reifiable types in instanceof enabled?
 191      */
 192     boolean allowReifiableTypesInInstanceof;
 193 
 194     /** Are records allowed
 195      */
 196     private final boolean allowRecords;
 197 
 198     /** Are patterns in switch allowed
 199      */
 200     private final boolean allowPatternSwitch;
 201 
 202     /** Are unconditional patterns in instanceof allowed
 203      */
 204     private final boolean allowUnconditionalPatternsInstanceOf;
 205 
 206     /**
 207      * Switch: warn about use of variable before declaration?
 208      * RFE: 6425594
 209      */
 210     boolean useBeforeDeclarationWarning;
 211 
 212     /**
 213      * Switch: name of source level; used for error reporting.
 214      */
 215     String sourceName;
 216 
 217     /** Check kind and type of given tree against protokind and prototype.
 218      *  If check succeeds, store type in tree and return it.
 219      *  If check fails, store errType in tree and return it.
 220      *  No checks are performed if the prototype is a method type.
 221      *  It is not necessary in this case since we know that kind and type
 222      *  are correct.
 223      *
 224      *  @param tree     The tree whose kind and type is checked
 225      *  @param found    The computed type of the tree
 226      *  @param ownkind  The computed kind of the tree
 227      *  @param resultInfo  The expected result of the tree
 228      */
 229     Type check(final JCTree tree,
 230                final Type found,
 231                final KindSelector ownkind,
 232                final ResultInfo resultInfo) {
 233         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 234         Type owntype;
 235         boolean shouldCheck = !found.hasTag(ERROR) &&
 236                 !resultInfo.pt.hasTag(METHOD) &&
 237                 !resultInfo.pt.hasTag(FORALL);
 238         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 239             log.error(tree.pos(),
 240                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 241                                             ownkind.kindNames()));
 242             owntype = types.createErrorType(found);
 243         } else if (inferenceContext.free(found)) {
 244             //delay the check if there are inference variables in the found type
 245             //this means we are dealing with a partially inferred poly expression
 246             owntype = shouldCheck ? resultInfo.pt : found;
 247             if (resultInfo.checkMode.installPostInferenceHook()) {
 248                 inferenceContext.addFreeTypeListener(List.of(found),
 249                         instantiatedContext -> {
 250                             ResultInfo pendingResult =
 251                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 252                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 253                         });
 254             }
 255         } else {
 256             owntype = shouldCheck ?
 257             resultInfo.check(tree, found) :
 258             found;
 259         }
 260         if (resultInfo.checkMode.updateTreeType()) {
 261             tree.type = owntype;
 262         }
 263         return owntype;
 264     }
 265 
 266     /** Is given blank final variable assignable, i.e. in a scope where it
 267      *  may be assigned to even though it is final?
 268      *  @param v      The blank final variable.
 269      *  @param env    The current environment.
 270      */
 271     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 272         Symbol owner = env.info.scope.owner;
 273            // owner refers to the innermost variable, method or
 274            // initializer block declaration at this point.
 275         boolean isAssignable =
 276             v.owner == owner
 277             ||
 278             ((owner.name == names.init ||    // i.e. we are in a constructor
 279               owner.kind == VAR ||           // i.e. we are in a variable initializer
 280               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 281              &&
 282              v.owner == owner.owner
 283              &&
 284              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 285         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 286         return isAssignable & !insideCompactConstructor;
 287     }
 288 
 289     /** Check that variable can be assigned to.
 290      *  @param pos    The current source code position.
 291      *  @param v      The assigned variable
 292      *  @param base   If the variable is referred to in a Select, the part
 293      *                to the left of the `.', null otherwise.
 294      *  @param env    The current environment.
 295      */
 296     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 297         if (v.name == names._this) {
 298             log.error(pos, Errors.CantAssignValToThis);
 299             return;
 300         }
 301         if ((v.flags() & FINAL) != 0 &&
 302             ((v.flags() & HASINIT) != 0
 303              ||
 304              !((base == null ||
 305                TreeInfo.isThisQualifier(base)) &&
 306                isAssignableAsBlankFinal(v, env)))) {
 307             if (v.isResourceVariable()) { //TWR resource
 308                 log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
 309             } else {
 310                 log.error(pos, Errors.CantAssignValToVar(Flags.toSource(v.flags() & (STATIC | FINAL)), v));
 311             }
 312             return;
 313         }
 314 
 315         // Check instance field assignments that appear in constructor prologues
 316         if (rs.isEarlyReference(env, base, v)) {
 317 
 318             // Field may not be inherited from a superclass
 319             if (v.owner != env.enclClass.sym) {
 320                 log.error(pos, Errors.CantRefBeforeCtorCalled(v));
 321                 return;
 322             }
 323 
 324             // Field may not have an initializer
 325             if ((v.flags() & HASINIT) != 0) {
 326                 log.error(pos, Errors.CantAssignInitializedBeforeCtorCalled(v));
 327                 return;
 328             }
 329         }
 330     }
 331 
 332     /** Does tree represent a static reference to an identifier?
 333      *  It is assumed that tree is either a SELECT or an IDENT.
 334      *  We have to weed out selects from non-type names here.
 335      *  @param tree    The candidate tree.
 336      */
 337     boolean isStaticReference(JCTree tree) {
 338         if (tree.hasTag(SELECT)) {
 339             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 340             if (lsym == null || lsym.kind != TYP) {
 341                 return false;
 342             }
 343         }
 344         return true;
 345     }
 346 
 347     /** Is this symbol a type?
 348      */
 349     static boolean isType(Symbol sym) {
 350         return sym != null && sym.kind == TYP;
 351     }
 352 
 353     /** Attribute a parsed identifier.
 354      * @param tree Parsed identifier name
 355      * @param topLevel The toplevel to use
 356      */
 357     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 358         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 359         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 360                                            syms.errSymbol.name,
 361                                            null, null, null, null);
 362         localEnv.enclClass.sym = syms.errSymbol;
 363         return attribIdent(tree, localEnv);
 364     }
 365 
 366     /** Attribute a parsed identifier.
 367      * @param tree Parsed identifier name
 368      * @param env The env to use
 369      */
 370     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 371         return tree.accept(identAttributer, env);
 372     }
 373     // where
 374         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 375         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 376             @Override @DefinedBy(Api.COMPILER_TREE)
 377             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 378                 Symbol site = visit(node.getExpression(), env);
 379                 if (site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 380                     return site;
 381                 Name name = (Name)node.getIdentifier();
 382                 if (site.kind == PCK) {
 383                     env.toplevel.packge = (PackageSymbol)site;
 384                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 385                             KindSelector.TYP_PCK);
 386                 } else {
 387                     env.enclClass.sym = (ClassSymbol)site;
 388                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 389                 }
 390             }
 391 
 392             @Override @DefinedBy(Api.COMPILER_TREE)
 393             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 394                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 395             }
 396         }
 397 
 398     public Type coerce(Type etype, Type ttype) {
 399         return cfolder.coerce(etype, ttype);
 400     }
 401 
 402     public Type attribType(JCTree node, TypeSymbol sym) {
 403         Env<AttrContext> env = typeEnvs.get(sym);
 404         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 405         return attribTree(node, localEnv, unknownTypeInfo);
 406     }
 407 
 408     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 409         // Attribute qualifying package or class.
 410         JCFieldAccess s = tree.qualid;
 411         return attribTree(s.selected, env,
 412                           new ResultInfo(tree.staticImport ?
 413                                          KindSelector.TYP : KindSelector.TYP_PCK,
 414                        Type.noType));
 415     }
 416 
 417     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 418         return attribToTree(expr, env, tree, unknownExprInfo);
 419     }
 420 
 421     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 422         return attribToTree(stmt, env, tree, statInfo);
 423     }
 424 
 425     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 426         breakTree = tree;
 427         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 428         try {
 429             deferredAttr.attribSpeculative(root, env, resultInfo,
 430                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 431                     argumentAttr.withLocalCacheContext());
 432             attrRecover.doRecovery();
 433         } catch (BreakAttr b) {
 434             return b.env;
 435         } catch (AssertionError ae) {
 436             if (ae.getCause() instanceof BreakAttr breakAttr) {
 437                 return breakAttr.env;
 438             } else {
 439                 throw ae;
 440             }
 441         } finally {
 442             breakTree = null;
 443             log.useSource(prev);
 444         }
 445         return env;
 446     }
 447 
 448     public <R> R runWithAttributedMethod(Env<AttrContext> env, JCMethodDecl tree, Function<JCBlock, R> attributedAction) {
 449         JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 450         try {
 451             JCBlock dupTree = (JCBlock)deferredAttr.attribSpeculative(tree.body, env, statInfo,
 452                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 453                     argumentAttr.withLocalCacheContext());
 454             return attributedAction.apply(dupTree);
 455         } finally {
 456             attrRecover.doRecovery();
 457             log.useSource(prevSource);
 458         }
 459     }
 460 
 461     private JCTree breakTree = null;
 462 
 463     private static class BreakAttr extends RuntimeException {
 464         static final long serialVersionUID = -6924771130405446405L;
 465         private transient Env<AttrContext> env;
 466         private BreakAttr(Env<AttrContext> env) {
 467             this.env = env;
 468         }
 469     }
 470 
 471     /**
 472      * Mode controlling behavior of Attr.Check
 473      */
 474     enum CheckMode {
 475 
 476         NORMAL,
 477 
 478         /**
 479          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 480          * that the captured var cache in {@code InferenceContext} will be used in read-only
 481          * mode when performing inference checks.
 482          */
 483         NO_TREE_UPDATE {
 484             @Override
 485             public boolean updateTreeType() {
 486                 return false;
 487             }
 488         },
 489         /**
 490          * Mode signalling that caller will manage free types in tree decorations.
 491          */
 492         NO_INFERENCE_HOOK {
 493             @Override
 494             public boolean installPostInferenceHook() {
 495                 return false;
 496             }
 497         };
 498 
 499         public boolean updateTreeType() {
 500             return true;
 501         }
 502         public boolean installPostInferenceHook() {
 503             return true;
 504         }
 505     }
 506 
 507 
 508     class ResultInfo {
 509         final KindSelector pkind;
 510         final Type pt;
 511         final CheckContext checkContext;
 512         final CheckMode checkMode;
 513 
 514         ResultInfo(KindSelector pkind, Type pt) {
 515             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 516         }
 517 
 518         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 519             this(pkind, pt, chk.basicHandler, checkMode);
 520         }
 521 
 522         protected ResultInfo(KindSelector pkind,
 523                              Type pt, CheckContext checkContext) {
 524             this(pkind, pt, checkContext, CheckMode.NORMAL);
 525         }
 526 
 527         protected ResultInfo(KindSelector pkind,
 528                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 529             this.pkind = pkind;
 530             this.pt = pt;
 531             this.checkContext = checkContext;
 532             this.checkMode = checkMode;
 533         }
 534 
 535         /**
 536          * Should {@link Attr#attribTree} use the {@code ArgumentAttr} visitor instead of this one?
 537          * @param tree The tree to be type-checked.
 538          * @return true if {@code ArgumentAttr} should be used.
 539          */
 540         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 541 
 542         protected Type check(final DiagnosticPosition pos, final Type found) {
 543             return chk.checkType(pos, found, pt, checkContext);
 544         }
 545 
 546         protected ResultInfo dup(Type newPt) {
 547             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 548         }
 549 
 550         protected ResultInfo dup(CheckContext newContext) {
 551             return new ResultInfo(pkind, pt, newContext, checkMode);
 552         }
 553 
 554         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 555             return new ResultInfo(pkind, newPt, newContext, checkMode);
 556         }
 557 
 558         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 559             return new ResultInfo(pkind, newPt, newContext, newMode);
 560         }
 561 
 562         protected ResultInfo dup(CheckMode newMode) {
 563             return new ResultInfo(pkind, pt, checkContext, newMode);
 564         }
 565 
 566         @Override
 567         public String toString() {
 568             if (pt != null) {
 569                 return pt.toString();
 570             } else {
 571                 return "";
 572             }
 573         }
 574     }
 575 
 576     class MethodAttrInfo extends ResultInfo {
 577         public MethodAttrInfo() {
 578             this(chk.basicHandler);
 579         }
 580 
 581         public MethodAttrInfo(CheckContext checkContext) {
 582             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 583         }
 584 
 585         @Override
 586         protected boolean needsArgumentAttr(JCTree tree) {
 587             return true;
 588         }
 589 
 590         protected ResultInfo dup(Type newPt) {
 591             throw new IllegalStateException();
 592         }
 593 
 594         protected ResultInfo dup(CheckContext newContext) {
 595             return new MethodAttrInfo(newContext);
 596         }
 597 
 598         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 599             throw new IllegalStateException();
 600         }
 601 
 602         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 603             throw new IllegalStateException();
 604         }
 605 
 606         protected ResultInfo dup(CheckMode newMode) {
 607             throw new IllegalStateException();
 608         }
 609     }
 610 
 611     class RecoveryInfo extends ResultInfo {
 612 
 613         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 614             this(deferredAttrContext, Type.recoveryType);
 615         }
 616 
 617         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 618             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 619                 @Override
 620                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 621                     return deferredAttrContext;
 622                 }
 623                 @Override
 624                 public boolean compatible(Type found, Type req, Warner warn) {
 625                     return true;
 626                 }
 627                 @Override
 628                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 629                     boolean needsReport = pt == Type.recoveryType ||
 630                             (details.getDiagnosticPosition() != null &&
 631                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 632                     if (needsReport) {
 633                         chk.basicHandler.report(pos, details);
 634                     }
 635                 }
 636             });
 637         }
 638     }
 639 
 640     final ResultInfo statInfo;
 641     final ResultInfo varAssignmentInfo;
 642     final ResultInfo methodAttrInfo;
 643     final ResultInfo unknownExprInfo;
 644     final ResultInfo unknownTypeInfo;
 645     final ResultInfo unknownTypeExprInfo;
 646     final ResultInfo recoveryInfo;
 647     final MethodType initBlockType;
 648 
 649     Type pt() {
 650         return resultInfo.pt;
 651     }
 652 
 653     KindSelector pkind() {
 654         return resultInfo.pkind;
 655     }
 656 
 657 /* ************************************************************************
 658  * Visitor methods
 659  *************************************************************************/
 660 
 661     /** Visitor argument: the current environment.
 662      */
 663     Env<AttrContext> env;
 664 
 665     /** Visitor argument: the currently expected attribution result.
 666      */
 667     ResultInfo resultInfo;
 668 
 669     /** Visitor result: the computed type.
 670      */
 671     Type result;
 672 
 673     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 674 
 675     /** Visitor method: attribute a tree, catching any completion failure
 676      *  exceptions. Return the tree's type.
 677      *
 678      *  @param tree    The tree to be visited.
 679      *  @param env     The environment visitor argument.
 680      *  @param resultInfo   The result info visitor argument.
 681      */
 682     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 683         Env<AttrContext> prevEnv = this.env;
 684         ResultInfo prevResult = this.resultInfo;
 685         try {
 686             this.env = env;
 687             this.resultInfo = resultInfo;
 688             if (resultInfo.needsArgumentAttr(tree)) {
 689                 result = argumentAttr.attribArg(tree, env);
 690             } else {
 691                 tree.accept(this);
 692             }
 693             matchBindings = matchBindingsComputer.finishBindings(tree,
 694                                                                  matchBindings);
 695             if (tree == breakTree &&
 696                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 697                 breakTreeFound(copyEnv(env));
 698             }
 699             return result;
 700         } catch (CompletionFailure ex) {
 701             tree.type = syms.errType;
 702             return chk.completionError(tree.pos(), ex);
 703         } finally {
 704             this.env = prevEnv;
 705             this.resultInfo = prevResult;
 706         }
 707     }
 708 
 709     protected void breakTreeFound(Env<AttrContext> env) {
 710         throw new BreakAttr(env);
 711     }
 712 
 713     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 714         Env<AttrContext> newEnv =
 715                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 716         if (newEnv.outer != null) {
 717             newEnv.outer = copyEnv(newEnv.outer);
 718         }
 719         return newEnv;
 720     }
 721 
 722     WriteableScope copyScope(WriteableScope sc) {
 723         WriteableScope newScope = WriteableScope.create(sc.owner);
 724         List<Symbol> elemsList = List.nil();
 725         for (Symbol sym : sc.getSymbols()) {
 726             elemsList = elemsList.prepend(sym);
 727         }
 728         for (Symbol s : elemsList) {
 729             newScope.enter(s);
 730         }
 731         return newScope;
 732     }
 733 
 734     /** Derived visitor method: attribute an expression tree.
 735      */
 736     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 737         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 738     }
 739 
 740     /** Derived visitor method: attribute an expression tree with
 741      *  no constraints on the computed type.
 742      */
 743     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 744         return attribTree(tree, env, unknownExprInfo);
 745     }
 746 
 747     /** Derived visitor method: attribute a type tree.
 748      */
 749     public Type attribType(JCTree tree, Env<AttrContext> env) {
 750         Type result = attribType(tree, env, Type.noType);
 751         return result;
 752     }
 753 
 754     /** Derived visitor method: attribute a type tree.
 755      */
 756     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 757         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 758         return result;
 759     }
 760 
 761     /** Derived visitor method: attribute a statement or definition tree.
 762      */
 763     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 764         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 765         Type result = attribTree(tree, env, statInfo);
 766         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 767         attrRecover.doRecovery();
 768         return result;
 769     }
 770 
 771     /** Attribute a list of expressions, returning a list of types.
 772      */
 773     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 774         ListBuffer<Type> ts = new ListBuffer<>();
 775         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 776             ts.append(attribExpr(l.head, env, pt));
 777         return ts.toList();
 778     }
 779 
 780     /** Attribute a list of statements, returning nothing.
 781      */
 782     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 783         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 784             attribStat(l.head, env);
 785     }
 786 
 787     /** Attribute the arguments in a method call, returning the method kind.
 788      */
 789     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 790         KindSelector kind = initialKind;
 791         for (JCExpression arg : trees) {
 792             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 793             if (argtype.hasTag(DEFERRED)) {
 794                 kind = KindSelector.of(KindSelector.POLY, kind);
 795             }
 796             argtypes.append(argtype);
 797         }
 798         return kind;
 799     }
 800 
 801     /** Attribute a type argument list, returning a list of types.
 802      *  Caller is responsible for calling checkRefTypes.
 803      */
 804     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 805         ListBuffer<Type> argtypes = new ListBuffer<>();
 806         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 807             argtypes.append(attribType(l.head, env));
 808         return argtypes.toList();
 809     }
 810 
 811     /** Attribute a type argument list, returning a list of types.
 812      *  Check that all the types are references.
 813      */
 814     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 815         List<Type> types = attribAnyTypes(trees, env);
 816         return chk.checkRefTypes(trees, types);
 817     }
 818 
 819     /**
 820      * Attribute type variables (of generic classes or methods).
 821      * Compound types are attributed later in attribBounds.
 822      * @param typarams the type variables to enter
 823      * @param env      the current environment
 824      */
 825     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 826         for (JCTypeParameter tvar : typarams) {
 827             TypeVar a = (TypeVar)tvar.type;
 828             a.tsym.flags_field |= UNATTRIBUTED;
 829             a.setUpperBound(Type.noType);
 830             if (!tvar.bounds.isEmpty()) {
 831                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 832                 for (JCExpression bound : tvar.bounds.tail)
 833                     bounds = bounds.prepend(attribType(bound, env));
 834                 types.setBounds(a, bounds.reverse());
 835             } else {
 836                 // if no bounds are given, assume a single bound of
 837                 // java.lang.Object.
 838                 types.setBounds(a, List.of(syms.objectType));
 839             }
 840             a.tsym.flags_field &= ~UNATTRIBUTED;
 841         }
 842         if (checkCyclic) {
 843             for (JCTypeParameter tvar : typarams) {
 844                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 845             }
 846         }
 847     }
 848 
 849     /**
 850      * Attribute the type references in a list of annotations.
 851      */
 852     void attribAnnotationTypes(List<JCAnnotation> annotations,
 853                                Env<AttrContext> env) {
 854         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 855             JCAnnotation a = al.head;
 856             attribType(a.annotationType, env);
 857         }
 858     }
 859 
 860     /**
 861      * Attribute a "lazy constant value".
 862      *  @param env         The env for the const value
 863      *  @param variable    The initializer for the const value
 864      *  @param type        The expected type, or null
 865      *  @see VarSymbol#setLazyConstValue
 866      */
 867     public Object attribLazyConstantValue(Env<AttrContext> env,
 868                                       Env<AttrContext> enclosingEnv,
 869                                       JCVariableDecl variable,
 870                                       Type type) {
 871         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 872         try {
 873             doQueueScanTreeAndTypeAnnotateForVarInit(variable, enclosingEnv);
 874             Type itype = attribExpr(variable.init, env, type);
 875             if (variable.isImplicitlyTyped()) {
 876                 //fixup local variable type
 877                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 878             }
 879             if (itype.constValue() != null) {
 880                 return coerce(itype, type).constValue();
 881             } else {
 882                 return null;
 883             }
 884         } finally {
 885             log.useSource(prevSource);
 886         }
 887     }
 888 
 889     /** Attribute type reference in an `extends', `implements', or 'permits' clause.
 890      *  Supertypes of anonymous inner classes are usually already attributed.
 891      *
 892      *  @param tree              The tree making up the type reference.
 893      *  @param env               The environment current at the reference.
 894      *  @param classExpected     true if only a class is expected here.
 895      *  @param interfaceExpected true if only an interface is expected here.
 896      */
 897     Type attribBase(JCTree tree,
 898                     Env<AttrContext> env,
 899                     boolean classExpected,
 900                     boolean interfaceExpected,
 901                     boolean checkExtensible) {
 902         Type t = tree.type != null ?
 903             tree.type :
 904             attribType(tree, env);
 905         try {
 906             return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 907         } catch (CompletionFailure ex) {
 908             chk.completionError(tree.pos(), ex);
 909             return t;
 910         }
 911     }
 912     Type checkBase(Type t,
 913                    JCTree tree,
 914                    Env<AttrContext> env,
 915                    boolean classExpected,
 916                    boolean interfaceExpected,
 917                    boolean checkExtensible) {
 918         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 919                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 920         if (t.tsym.isAnonymous()) {
 921             log.error(pos, Errors.CantInheritFromAnon);
 922             return types.createErrorType(t);
 923         }
 924         if (t.isErroneous())
 925             return t;
 926         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 927             // check that type variable is already visible
 928             if (t.getUpperBound() == null) {
 929                 log.error(pos, Errors.IllegalForwardRef);
 930                 return types.createErrorType(t);
 931             }
 932         } else {
 933             t = chk.checkClassType(pos, t, checkExtensible);
 934         }
 935         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 936             log.error(pos, Errors.IntfExpectedHere);
 937             // return errType is necessary since otherwise there might
 938             // be undetected cycles which cause attribution to loop
 939             return types.createErrorType(t);
 940         } else if (checkExtensible &&
 941                    classExpected &&
 942                    (t.tsym.flags() & INTERFACE) != 0) {
 943             log.error(pos, Errors.NoIntfExpectedHere);
 944             return types.createErrorType(t);
 945         }
 946         if (checkExtensible &&
 947             ((t.tsym.flags() & FINAL) != 0)) {
 948             log.error(pos,
 949                       Errors.CantInheritFromFinal(t.tsym));
 950         }
 951         chk.checkNonCyclic(pos, t);
 952         return t;
 953     }
 954 
 955     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 956         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 957         id.type = env.info.scope.owner.enclClass().type;
 958         id.sym = env.info.scope.owner.enclClass();
 959         return id.type;
 960     }
 961 
 962     public void visitClassDef(JCClassDecl tree) {
 963         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 964                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 965                         argumentAttr.withLocalCacheContext() : null);
 966         boolean ctorProloguePrev = env.info.ctorPrologue;
 967         try {
 968             // Local and anonymous classes have not been entered yet, so we need to
 969             // do it now.
 970             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 971                 enter.classEnter(tree, env);
 972             } else {
 973                 // If this class declaration is part of a class level annotation,
 974                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 975                 // order to simplify later steps and allow for sensible error
 976                 // messages.
 977                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 978                     enter.classEnter(tree, env);
 979             }
 980 
 981             ClassSymbol c = tree.sym;
 982             if (c == null) {
 983                 // exit in case something drastic went wrong during enter.
 984                 result = null;
 985             } else {
 986                 // make sure class has been completed:
 987                 c.complete();
 988 
 989                 // If a class declaration appears in a constructor prologue,
 990                 // that means it's either a local class or an anonymous class.
 991                 // Either way, there is no immediately enclosing instance.
 992                 if (ctorProloguePrev) {
 993                     c.flags_field |= NOOUTERTHIS;
 994                 }
 995                 attribClass(tree.pos(), c);
 996                 result = tree.type = c.type;
 997             }
 998         } finally {
 999             localCacheContext.ifPresent(LocalCacheContext::leave);
1000             env.info.ctorPrologue = ctorProloguePrev;
1001         }
1002     }
1003 
1004     public void visitMethodDef(JCMethodDecl tree) {
1005         MethodSymbol m = tree.sym;
1006         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
1007 
1008         Lint lint = env.info.lint.augment(m);
1009         Lint prevLint = chk.setLint(lint);
1010         boolean ctorProloguePrev = env.info.ctorPrologue;
1011         Assert.check(!env.info.ctorPrologue);
1012         MethodSymbol prevMethod = chk.setMethod(m);
1013         try {
1014             chk.checkDeprecatedAnnotation(tree.pos(), m);
1015 
1016 
1017             // Create a new environment with local scope
1018             // for attributing the method.
1019             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
1020             localEnv.info.lint = lint;
1021 
1022             attribStats(tree.typarams, localEnv);
1023 
1024             // If we override any other methods, check that we do so properly.
1025             // JLS ???
1026             if (m.isStatic()) {
1027                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1028             } else {
1029                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1030             }
1031             chk.checkOverride(env, tree, m);
1032 
1033             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1034                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1035             }
1036 
1037             // Enter all type parameters into the local method scope.
1038             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1039                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1040 
1041             ClassSymbol owner = env.enclClass.sym;
1042             if ((owner.flags() & ANNOTATION) != 0 &&
1043                     (tree.params.nonEmpty() ||
1044                     tree.recvparam != null))
1045                 log.error(tree.params.nonEmpty() ?
1046                         tree.params.head.pos() :
1047                         tree.recvparam.pos(),
1048                         Errors.IntfAnnotationMembersCantHaveParams);
1049 
1050             // Attribute all value parameters.
1051             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1052                 attribStat(l.head, localEnv);
1053             }
1054 
1055             chk.checkVarargsMethodDecl(localEnv, tree);
1056 
1057             // Check that type parameters are well-formed.
1058             chk.validate(tree.typarams, localEnv);
1059 
1060             // Check that result type is well-formed.
1061             if (tree.restype != null && !tree.restype.type.hasTag(VOID)) {
1062                 chk.validate(tree.restype, localEnv);
1063             }
1064             chk.checkRequiresIdentity(tree, env.info.lint);
1065 
1066             // Check that receiver type is well-formed.
1067             if (tree.recvparam != null) {
1068                 // Use a new environment to check the receiver parameter.
1069                 // Otherwise I get "might not have been initialized" errors.
1070                 // Is there a better way?
1071                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1072                 attribType(tree.recvparam, newEnv);
1073                 chk.validate(tree.recvparam, newEnv);
1074             }
1075 
1076             // Is this method a constructor?
1077             boolean isConstructor = TreeInfo.isConstructor(tree);
1078 
1079             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1080                 // lets find if this method is an accessor
1081                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1082                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1083                 if (recordComponent.isPresent()) {
1084                     // the method is a user defined accessor lets check that everything is fine
1085                     if (!tree.sym.isPublic()) {
1086                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1087                     }
1088                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1089                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1090                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1091                     }
1092                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1093                         log.error(tree,
1094                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1095                     }
1096                     if (!tree.typarams.isEmpty()) {
1097                         log.error(tree,
1098                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1099                     }
1100                     if (tree.sym.isStatic()) {
1101                         log.error(tree,
1102                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1103                     }
1104                 }
1105 
1106                 if (isConstructor) {
1107                     // if this a constructor other than the canonical one
1108                     if ((tree.sym.flags_field & RECORD) == 0) {
1109                         if (!TreeInfo.hasConstructorCall(tree, names._this)) {
1110                             log.error(tree, Errors.NonCanonicalConstructorInvokeAnotherConstructor(env.enclClass.sym));
1111                         }
1112                     } else {
1113                         // but if it is the canonical:
1114 
1115                         /* if user generated, then it shouldn't:
1116                          *     - have an accessibility stricter than that of the record type
1117                          *     - explicitly invoke any other constructor
1118                          */
1119                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1120                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1121                                 log.error(tree,
1122                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1123                                             Errors.InvalidCanonicalConstructorInRecord(
1124                                                 Fragments.Canonical,
1125                                                 env.enclClass.sym.name,
1126                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1127                                             ) :
1128                                             Errors.InvalidCanonicalConstructorInRecord(
1129                                                     Fragments.Canonical,
1130                                                     env.enclClass.sym.name,
1131                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1132                                             )
1133                                 );
1134                             }
1135 
1136                             if (TreeInfo.hasAnyConstructorCall(tree)) {
1137                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1138                                         Fragments.Canonical, env.enclClass.sym.name,
1139                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1140                             }
1141                         }
1142 
1143                         // also we want to check that no type variables have been defined
1144                         if (!tree.typarams.isEmpty()) {
1145                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1146                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1147                         }
1148 
1149                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1150                          * record components
1151                          */
1152                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1153                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1154                         for (JCVariableDecl param: tree.params) {
1155                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1156                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1157                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1158                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1159                                         Fragments.Canonical, env.enclClass.sym.name,
1160                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1161                             }
1162                             recordComponents = recordComponents.tail;
1163                             recordFieldTypes = recordFieldTypes.tail;
1164                         }
1165                     }
1166                 }
1167             }
1168 
1169             // annotation method checks
1170             if ((owner.flags() & ANNOTATION) != 0) {
1171                 // annotation method cannot have throws clause
1172                 if (tree.thrown.nonEmpty()) {
1173                     log.error(tree.thrown.head.pos(),
1174                               Errors.ThrowsNotAllowedInIntfAnnotation);
1175                 }
1176                 // annotation method cannot declare type-parameters
1177                 if (tree.typarams.nonEmpty()) {
1178                     log.error(tree.typarams.head.pos(),
1179                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1180                 }
1181                 // validate annotation method's return type (could be an annotation type)
1182                 chk.validateAnnotationType(tree.restype);
1183                 // ensure that annotation method does not clash with members of Object/Annotation
1184                 chk.validateAnnotationMethod(tree.pos(), m);
1185             }
1186 
1187             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1188                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1189 
1190             if (tree.body == null) {
1191                 // Empty bodies are only allowed for
1192                 // abstract, native, or interface methods, or for methods
1193                 // in a retrofit signature class.
1194                 if (tree.defaultValue != null) {
1195                     if ((owner.flags() & ANNOTATION) == 0)
1196                         log.error(tree.pos(),
1197                                   Errors.DefaultAllowedInIntfAnnotationMember);
1198                 }
1199                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1200                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract(tree.sym, owner));
1201             } else {
1202                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1203                     if ((owner.flags() & INTERFACE) != 0) {
1204                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1205                     } else {
1206                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1207                     }
1208                 } else if ((tree.mods.flags & NATIVE) != 0) {
1209                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1210                 }
1211                 // Add an implicit super() call unless an explicit call to
1212                 // super(...) or this(...) is given
1213                 // or we are compiling class java.lang.Object.
1214                 if (isConstructor && owner.type != syms.objectType) {
1215                     if (!TreeInfo.hasAnyConstructorCall(tree)) {
1216                         JCStatement supCall = make.at(tree.body.pos).Exec(make.Apply(List.nil(),
1217                                 make.Ident(names._super), make.Idents(List.nil())));
1218                         tree.body.stats = tree.body.stats.prepend(supCall);
1219                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1220                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1221                             TreeInfo.hasConstructorCall(tree, names._super)) {
1222                         // enum constructors are not allowed to call super
1223                         // directly, so make sure there aren't any super calls
1224                         // in enum constructors, except in the compiler
1225                         // generated one.
1226                         log.error(tree.body.stats.head.pos(),
1227                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1228                     }
1229                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1230                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1231                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1232                         if (!initParamNames.equals(recordComponentNames)) {
1233                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1234                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1235                         }
1236                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1237                             log.error(tree,
1238                                     Errors.InvalidCanonicalConstructorInRecord(
1239                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1240                                             env.enclClass.sym.name,
1241                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1242                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1243                         }
1244                     }
1245                 }
1246 
1247                 // Attribute all type annotations in the body
1248                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m);
1249                 annotate.flush();
1250 
1251                 // Start of constructor prologue (if not in java.lang.Object constructor)
1252                 localEnv.info.ctorPrologue = isConstructor && owner.type != syms.objectType;
1253 
1254                 // Attribute method body.
1255                 attribStat(tree.body, localEnv);
1256             }
1257 
1258             localEnv.info.scope.leave();
1259             result = tree.type = m.type;
1260         } finally {
1261             chk.setLint(prevLint);
1262             chk.setMethod(prevMethod);
1263             env.info.ctorPrologue = ctorProloguePrev;
1264         }
1265     }
1266 
1267     public void visitVarDef(JCVariableDecl tree) {
1268         // Local variables have not been entered yet, so we need to do it now:
1269         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1270             if (tree.sym != null) {
1271                 // parameters have already been entered
1272                 env.info.scope.enter(tree.sym);
1273             } else {
1274                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
1275                     if (tree.init == null) {
1276                         //cannot use 'var' without initializer
1277                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1278                         tree.vartype = make.at(tree.pos()).Erroneous();
1279                     } else {
1280                         Fragment msg = canInferLocalVarType(tree);
1281                         if (msg != null) {
1282                             //cannot use 'var' with initializer which require an explicit target
1283                             //(e.g. lambda, method reference, array initializer).
1284                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1285                             tree.vartype = make.at(tree.pos()).Erroneous();
1286                         }
1287                     }
1288                 }
1289                 try {
1290                     annotate.blockAnnotations();
1291                     memberEnter.memberEnter(tree, env);
1292                 } finally {
1293                     annotate.unblockAnnotations();
1294                 }
1295             }
1296         } else {
1297             doQueueScanTreeAndTypeAnnotateForVarInit(tree, env);
1298         }
1299 
1300         VarSymbol v = tree.sym;
1301         Lint lint = env.info.lint.augment(v);
1302         Lint prevLint = chk.setLint(lint);
1303 
1304         // Check that the variable's declared type is well-formed.
1305         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1306                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1307                 (tree.sym.flags() & PARAMETER) != 0;
1308         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1309 
1310         try {
1311             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1312             chk.checkDeprecatedAnnotation(tree.pos(), v);
1313 
1314             if (tree.init != null) {
1315                 if ((v.flags_field & FINAL) == 0 ||
1316                     !memberEnter.needsLazyConstValue(tree.init)) {
1317                     // Not a compile-time constant
1318                     // Attribute initializer in a new environment
1319                     // with the declared variable as owner.
1320                     // Check that initializer conforms to variable's declared type.
1321                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
1322                     initEnv.info.lint = lint;
1323                     // In order to catch self-references, we set the variable's
1324                     // declaration position to maximal possible value, effectively
1325                     // marking the variable as undefined.
1326                     initEnv.info.enclVar = v;
1327                     attribExpr(tree.init, initEnv, v.type);
1328                     if (tree.isImplicitlyTyped()) {
1329                         //fixup local variable type
1330                         v.type = chk.checkLocalVarType(tree, tree.init.type, tree.name);
1331                     }
1332                 }
1333                 if (tree.isImplicitlyTyped()) {
1334                     setSyntheticVariableType(tree, v.type);
1335                 }
1336             }
1337             result = tree.type = v.type;
1338             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
1339                 if (isNonArgsMethodInObject(v.name)) {
1340                     log.error(tree, Errors.IllegalRecordComponentName(v));
1341                 }
1342             }
1343             chk.checkRequiresIdentity(tree, env.info.lint);
1344         }
1345         finally {
1346             chk.setLint(prevLint);
1347         }
1348     }
1349 
1350     private void doQueueScanTreeAndTypeAnnotateForVarInit(JCVariableDecl tree, Env<AttrContext> env) {
1351         if (tree.init != null &&
1352             (tree.mods.flags & Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED) == 0 &&
1353             env.info.scope.owner.kind != MTH && env.info.scope.owner.kind != VAR) {
1354             tree.mods.flags |= Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED;
1355             // Field initializer expression need to be entered.
1356             annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym);
1357             annotate.flush();
1358         }
1359     }
1360 
1361     private boolean isNonArgsMethodInObject(Name name) {
1362         for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
1363             if (s.type.getParameterTypes().isEmpty()) {
1364                 return true;
1365             }
1366         }
1367         return false;
1368     }
1369 
1370     Fragment canInferLocalVarType(JCVariableDecl tree) {
1371         LocalInitScanner lis = new LocalInitScanner();
1372         lis.scan(tree.init);
1373         return lis.badInferenceMsg;
1374     }
1375 
1376     static class LocalInitScanner extends TreeScanner {
1377         Fragment badInferenceMsg = null;
1378         boolean needsTarget = true;
1379 
1380         @Override
1381         public void visitNewArray(JCNewArray tree) {
1382             if (tree.elemtype == null && needsTarget) {
1383                 badInferenceMsg = Fragments.LocalArrayMissingTarget;
1384             }
1385         }
1386 
1387         @Override
1388         public void visitLambda(JCLambda tree) {
1389             if (needsTarget) {
1390                 badInferenceMsg = Fragments.LocalLambdaMissingTarget;
1391             }
1392         }
1393 
1394         @Override
1395         public void visitTypeCast(JCTypeCast tree) {
1396             boolean prevNeedsTarget = needsTarget;
1397             try {
1398                 needsTarget = false;
1399                 super.visitTypeCast(tree);
1400             } finally {
1401                 needsTarget = prevNeedsTarget;
1402             }
1403         }
1404 
1405         @Override
1406         public void visitReference(JCMemberReference tree) {
1407             if (needsTarget) {
1408                 badInferenceMsg = Fragments.LocalMrefMissingTarget;
1409             }
1410         }
1411 
1412         @Override
1413         public void visitNewClass(JCNewClass tree) {
1414             boolean prevNeedsTarget = needsTarget;
1415             try {
1416                 needsTarget = false;
1417                 super.visitNewClass(tree);
1418             } finally {
1419                 needsTarget = prevNeedsTarget;
1420             }
1421         }
1422 
1423         @Override
1424         public void visitApply(JCMethodInvocation tree) {
1425             boolean prevNeedsTarget = needsTarget;
1426             try {
1427                 needsTarget = false;
1428                 super.visitApply(tree);
1429             } finally {
1430                 needsTarget = prevNeedsTarget;
1431             }
1432         }
1433     }
1434 
1435     public void visitSkip(JCSkip tree) {
1436         result = null;
1437     }
1438 
1439     public void visitBlock(JCBlock tree) {
1440         if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
1441             // Block is a static or instance initializer;
1442             // let the owner of the environment be a freshly
1443             // created BLOCK-method.
1444             Symbol fakeOwner =
1445                 new MethodSymbol(tree.flags | BLOCK |
1446                     env.info.scope.owner.flags() & STRICTFP, names.empty, initBlockType,
1447                     env.info.scope.owner);
1448             final Env<AttrContext> localEnv =
1449                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
1450 
1451             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
1452             // Attribute all type annotations in the block
1453             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner);
1454             annotate.flush();
1455             attribStats(tree.stats, localEnv);
1456 
1457             {
1458                 // Store init and clinit type annotations with the ClassSymbol
1459                 // to allow output in Gen.normalizeDefs.
1460                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1461                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1462                 if ((tree.flags & STATIC) != 0) {
1463                     cs.appendClassInitTypeAttributes(tas);
1464                 } else {
1465                     cs.appendInitTypeAttributes(tas);
1466                 }
1467             }
1468         } else {
1469             // Create a new local environment with a local scope.
1470             Env<AttrContext> localEnv =
1471                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1472             try {
1473                 attribStats(tree.stats, localEnv);
1474             } finally {
1475                 localEnv.info.scope.leave();
1476             }
1477         }
1478         result = null;
1479     }
1480 
1481     public void visitDoLoop(JCDoWhileLoop tree) {
1482         attribStat(tree.body, env.dup(tree));
1483         attribExpr(tree.cond, env, syms.booleanType);
1484         handleLoopConditionBindings(matchBindings, tree, tree.body);
1485         result = null;
1486     }
1487 
1488     public void visitWhileLoop(JCWhileLoop tree) {
1489         attribExpr(tree.cond, env, syms.booleanType);
1490         MatchBindings condBindings = matchBindings;
1491         // include condition's bindings when true in the body:
1492         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1493         try {
1494             attribStat(tree.body, whileEnv.dup(tree));
1495         } finally {
1496             whileEnv.info.scope.leave();
1497         }
1498         handleLoopConditionBindings(condBindings, tree, tree.body);
1499         result = null;
1500     }
1501 
1502     public void visitForLoop(JCForLoop tree) {
1503         Env<AttrContext> loopEnv =
1504             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1505         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1506         try {
1507             attribStats(tree.init, loopEnv);
1508             if (tree.cond != null) {
1509                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1510                 // include condition's bindings when true in the body and step:
1511                 condBindings = matchBindings;
1512             }
1513             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1514             try {
1515                 bodyEnv.tree = tree; // before, we were not in loop!
1516                 attribStats(tree.step, bodyEnv);
1517                 attribStat(tree.body, bodyEnv);
1518             } finally {
1519                 bodyEnv.info.scope.leave();
1520             }
1521             result = null;
1522         }
1523         finally {
1524             loopEnv.info.scope.leave();
1525         }
1526         handleLoopConditionBindings(condBindings, tree, tree.body);
1527     }
1528 
1529     /**
1530      * Include condition's bindings when false after the loop, if cannot get out of the loop
1531      */
1532     private void handleLoopConditionBindings(MatchBindings condBindings,
1533                                              JCStatement loop,
1534                                              JCStatement loopBody) {
1535         if (condBindings.bindingsWhenFalse.nonEmpty() &&
1536             !breaksTo(env, loop, loopBody)) {
1537             addBindings2Scope(loop, condBindings.bindingsWhenFalse);
1538         }
1539     }
1540 
1541     private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
1542         preFlow(body);
1543         return flow.breaksToTree(env, loop, body, make);
1544     }
1545 
1546     /**
1547      * Add given bindings to the current scope, unless there's a break to
1548      * an immediately enclosing labeled statement.
1549      */
1550     private void addBindings2Scope(JCStatement introducingStatement,
1551                                    List<BindingSymbol> bindings) {
1552         if (bindings.isEmpty()) {
1553             return ;
1554         }
1555 
1556         var searchEnv = env;
1557         while (searchEnv.tree instanceof JCLabeledStatement labeled &&
1558                labeled.body == introducingStatement) {
1559             if (breaksTo(env, labeled, labeled.body)) {
1560                 //breaking to an immediately enclosing labeled statement
1561                 return ;
1562             }
1563             searchEnv = searchEnv.next;
1564             introducingStatement = labeled;
1565         }
1566 
1567         //include condition's body when false after the while, if cannot get out of the loop
1568         bindings.forEach(env.info.scope::enter);
1569         bindings.forEach(BindingSymbol::preserveBinding);
1570     }
1571 
1572     public void visitForeachLoop(JCEnhancedForLoop tree) {
1573         Env<AttrContext> loopEnv =
1574             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1575         try {
1576             //the Formal Parameter of a for-each loop is not in the scope when
1577             //attributing the for-each expression; we mimic this by attributing
1578             //the for-each expression first (against original scope).
1579             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1580             chk.checkNonVoid(tree.pos(), exprType);
1581             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1582             if (elemtype == null) {
1583                 // or perhaps expr implements Iterable<T>?
1584                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1585                 if (base == null) {
1586                     log.error(tree.expr.pos(),
1587                               Errors.ForeachNotApplicableToType(exprType,
1588                                                                 Fragments.TypeReqArrayOrIterable));
1589                     elemtype = types.createErrorType(exprType);
1590                 } else {
1591                     List<Type> iterableParams = base.allparams();
1592                     elemtype = iterableParams.isEmpty()
1593                         ? syms.objectType
1594                         : types.wildUpperBound(iterableParams.head);
1595 
1596                     // Check the return type of the method iterator().
1597                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1598                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1599                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1600                     if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
1601                         log.error(tree.pos(),
1602                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1603                     }
1604                 }
1605             }
1606             if (tree.var.isImplicitlyTyped()) {
1607                 Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
1608                 setSyntheticVariableType(tree.var, inferredType);
1609             }
1610             attribStat(tree.var, loopEnv);
1611             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1612             loopEnv.tree = tree; // before, we were not in loop!
1613             attribStat(tree.body, loopEnv);
1614             result = null;
1615         }
1616         finally {
1617             loopEnv.info.scope.leave();
1618         }
1619     }
1620 
1621     public void visitLabelled(JCLabeledStatement tree) {
1622         // Check that label is not used in an enclosing statement
1623         Env<AttrContext> env1 = env;
1624         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1625             if (env1.tree.hasTag(LABELLED) &&
1626                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1627                 log.error(tree.pos(),
1628                           Errors.LabelAlreadyInUse(tree.label));
1629                 break;
1630             }
1631             env1 = env1.next;
1632         }
1633 
1634         attribStat(tree.body, env.dup(tree));
1635         result = null;
1636     }
1637 
1638     public void visitSwitch(JCSwitch tree) {
1639         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1640             attribStats(c.stats, caseEnv);
1641         });
1642         result = null;
1643     }
1644 
1645     public void visitSwitchExpression(JCSwitchExpression tree) {
1646         boolean wrongContext = false;
1647 
1648         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
1649                 PolyKind.STANDALONE : PolyKind.POLY;
1650 
1651         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
1652             //this means we are returning a poly conditional from void-compatible lambda expression
1653             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
1654             resultInfo = recoveryInfo;
1655             wrongContext = true;
1656         }
1657 
1658         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
1659                 unknownExprInfo :
1660                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
1661 
1662         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
1663         ListBuffer<Type> caseTypes = new ListBuffer<>();
1664 
1665         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1666             caseEnv.info.yieldResult = condInfo;
1667             attribStats(c.stats, caseEnv);
1668             new TreeScanner() {
1669                 @Override
1670                 public void visitYield(JCYield brk) {
1671                     if (brk.target == tree) {
1672                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
1673                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
1674                     }
1675                     super.visitYield(brk);
1676                 }
1677 
1678                 @Override public void visitClassDef(JCClassDecl tree) {}
1679                 @Override public void visitLambda(JCLambda tree) {}
1680             }.scan(c.stats);
1681         });
1682 
1683         if (tree.cases.isEmpty()) {
1684             log.error(tree.pos(),
1685                       Errors.SwitchExpressionEmpty);
1686         } else if (caseTypes.isEmpty()) {
1687             log.error(tree.pos(),
1688                       Errors.SwitchExpressionNoResultExpressions);
1689         }
1690 
1691         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
1692 
1693         result = tree.type = wrongContext? types.createErrorType(pt()) : check(tree, owntype, KindSelector.VAL, resultInfo);
1694     }
1695     //where:
1696         CheckContext switchExpressionContext(CheckContext checkContext) {
1697             return new Check.NestedCheckContext(checkContext) {
1698                 //this will use enclosing check context to check compatibility of
1699                 //subexpression against target type; if we are in a method check context,
1700                 //depending on whether boxing is allowed, we could have incompatibilities
1701                 @Override
1702                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1703                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
1704                 }
1705             };
1706         }
1707 
1708     private void handleSwitch(JCTree switchTree,
1709                               JCExpression selector,
1710                               List<JCCase> cases,
1711                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
1712         Type seltype = attribExpr(selector, env);
1713         Type seltypeUnboxed = types.unboxedTypeOrType(seltype);
1714 
1715         Env<AttrContext> switchEnv =
1716             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
1717 
1718         try {
1719             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
1720             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
1721             boolean booleanSwitch = types.isSameType(seltypeUnboxed, syms.booleanType);
1722             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
1723             boolean intSwitch = types.isAssignable(seltype, syms.intType);
1724             boolean patternSwitch;
1725             if (seltype.isPrimitive() && !intSwitch) {
1726                 preview.checkSourceLevel(selector.pos(), Feature.PRIMITIVE_PATTERNS);
1727                 patternSwitch = true;
1728             }
1729             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
1730                 !intSwitch) {
1731                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
1732                 patternSwitch = true;
1733             } else {
1734                 patternSwitch = cases.stream()
1735                                      .flatMap(c -> c.labels.stream())
1736                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
1737                                                     TreeInfo.isNullCaseLabel(l));
1738             }
1739 
1740             // Attribute all cases and
1741             // check that there are no duplicate case labels or default clauses.
1742             Set<Object> constants = new HashSet<>(); // The set of case constants.
1743             boolean hasDefault = false;           // Is there a default label?
1744             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
1745             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
1746             boolean hasNullPattern = false;       // Is there a null pattern?
1747             CaseTree.CaseKind caseKind = null;
1748             boolean wasError = false;
1749             JCCaseLabel unconditionalCaseLabel = null;
1750             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
1751                 JCCase c = l.head;
1752                 if (caseKind == null) {
1753                     caseKind = c.caseKind;
1754                 } else if (caseKind != c.caseKind && !wasError) {
1755                     log.error(c.pos(),
1756                               Errors.SwitchMixingCaseTypes);
1757                     wasError = true;
1758                 }
1759                 MatchBindings currentBindings = null;
1760                 MatchBindings guardBindings = null;
1761                 for (List<JCCaseLabel> labels = c.labels; labels.nonEmpty(); labels = labels.tail) {
1762                     JCCaseLabel label = labels.head;
1763                     if (label instanceof JCConstantCaseLabel constLabel) {
1764                         JCExpression expr = constLabel.expr;
1765                         if (TreeInfo.isNull(expr)) {
1766                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
1767                             if (hasNullPattern) {
1768                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1769                             }
1770                             hasNullPattern = true;
1771                             attribExpr(expr, switchEnv, seltype);
1772                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
1773                         } else if (enumSwitch) {
1774                             Symbol sym = enumConstant(expr, seltype);
1775                             if (sym == null) {
1776                                 if (allowPatternSwitch) {
1777                                     attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1778                                     Symbol enumSym = TreeInfo.symbol(expr);
1779                                     if (enumSym == null || !enumSym.isEnum() || enumSym.kind != VAR) {
1780                                         log.error(expr.pos(), Errors.EnumLabelMustBeEnumConstant);
1781                                     } else if (!constants.add(enumSym)) {
1782                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1783                                     }
1784                                 } else {
1785                                     log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
1786                                 }
1787                             } else if (!constants.add(sym)) {
1788                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1789                             }
1790                         } else if (errorEnumSwitch) {
1791                             //error recovery: the selector is erroneous, and all the case labels
1792                             //are identifiers. This could be an enum switch - don't report resolve
1793                             //error for the case label:
1794                             var prevResolveHelper = rs.basicLogResolveHelper;
1795                             try {
1796                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
1797                                 attribExpr(expr, switchEnv, seltype);
1798                             } finally {
1799                                 rs.basicLogResolveHelper = prevResolveHelper;
1800                             }
1801                         } else {
1802                             Type pattype = attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1803                             if (!pattype.hasTag(ERROR)) {
1804                                 if (pattype.constValue() == null) {
1805                                     Symbol s = TreeInfo.symbol(expr);
1806                                     if (s != null && s.kind == TYP) {
1807                                         log.error(expr.pos(),
1808                                                   Errors.PatternExpected);
1809                                     } else if (s == null || !s.isEnum()) {
1810                                         log.error(expr.pos(),
1811                                                   (stringSwitch ? Errors.StringConstReq
1812                                                                 : intSwitch ? Errors.ConstExprReq
1813                                                                             : Errors.PatternOrEnumReq));
1814                                     } else if (!constants.add(s)) {
1815                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1816                                     }
1817                                 }
1818                                 else {
1819                                     boolean isLongFloatDoubleOrBooleanConstant =
1820                                             pattype.getTag().isInSuperClassesOf(LONG) || pattype.getTag().equals(BOOLEAN);
1821                                     if (isLongFloatDoubleOrBooleanConstant) {
1822                                         preview.checkSourceLevel(label.pos(), Feature.PRIMITIVE_PATTERNS);
1823                                     }
1824                                     if (!stringSwitch && !intSwitch && !(isLongFloatDoubleOrBooleanConstant && types.isSameType(seltypeUnboxed, pattype))) {
1825                                         log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
1826                                     } else if (!constants.add(pattype.constValue())) {
1827                                         log.error(c.pos(), Errors.DuplicateCaseLabel);
1828                                     }
1829                                 }
1830                             }
1831                         }
1832                     } else if (label instanceof JCDefaultCaseLabel def) {
1833                         if (hasDefault) {
1834                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
1835                         } else if (hasUnconditionalPattern) {
1836                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
1837                         }  else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1838                             log.error(label.pos(), Errors.DefaultAndBothBooleanValues);
1839                         }
1840                         hasDefault = true;
1841                         matchBindings = MatchBindingsComputer.EMPTY;
1842                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
1843                         //pattern
1844                         JCPattern pat = patternlabel.pat;
1845                         attribExpr(pat, switchEnv, seltype);
1846                         Type primaryType = TreeInfo.primaryPatternType(pat);
1847 
1848                         if (primaryType.isPrimitive()) {
1849                             preview.checkSourceLevel(pat.pos(), Feature.PRIMITIVE_PATTERNS);
1850                         } else if (!primaryType.hasTag(TYPEVAR)) {
1851                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
1852                         }
1853                         checkCastablePattern(pat.pos(), seltype, primaryType);
1854                         Type patternType = types.erasure(primaryType);
1855                         JCExpression guard = c.guard;
1856                         if (guardBindings == null && guard != null) {
1857                             MatchBindings afterPattern = matchBindings;
1858                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
1859                             try {
1860                                 attribExpr(guard, bodyEnv, syms.booleanType);
1861                             } finally {
1862                                 bodyEnv.info.scope.leave();
1863                             }
1864 
1865                             guardBindings = matchBindings;
1866                             matchBindings = afterPattern;
1867 
1868                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
1869                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
1870                             }
1871                         }
1872                         boolean unguarded = TreeInfo.unguardedCase(c) && !pat.hasTag(RECORDPATTERN);
1873                         boolean unconditional =
1874                                 unguarded &&
1875                                 !patternType.isErroneous() &&
1876                                 types.isUnconditionallyExact(seltype, patternType);
1877                         if (unconditional) {
1878                             if (hasUnconditionalPattern) {
1879                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
1880                             } else if (hasDefault) {
1881                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
1882                             } else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1883                                 log.error(pat.pos(), Errors.UnconditionalPatternAndBothBooleanValues);
1884                             }
1885                             hasUnconditionalPattern = true;
1886                             unconditionalCaseLabel = label;
1887                         }
1888                         lastPatternErroneous = patternType.isErroneous();
1889                     } else {
1890                         Assert.error();
1891                     }
1892                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
1893                 }
1894 
1895                 if (guardBindings != null) {
1896                     currentBindings = matchBindingsComputer.caseGuard(c, currentBindings, guardBindings);
1897                 }
1898 
1899                 Env<AttrContext> caseEnv =
1900                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
1901                 try {
1902                     attribCase.accept(c, caseEnv);
1903                 } finally {
1904                     caseEnv.info.scope.leave();
1905                 }
1906                 addVars(c.stats, switchEnv.info.scope);
1907 
1908                 preFlow(c);
1909                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
1910             }
1911             if (patternSwitch) {
1912                 chk.checkSwitchCaseStructure(cases);
1913                 chk.checkSwitchCaseLabelDominated(unconditionalCaseLabel, cases);
1914             }
1915             if (switchTree.hasTag(SWITCH)) {
1916                 ((JCSwitch) switchTree).hasUnconditionalPattern =
1917                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1918                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
1919             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
1920                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
1921                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1922                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
1923             } else {
1924                 Assert.error(switchTree.getTag().name());
1925             }
1926         } finally {
1927             switchEnv.info.scope.leave();
1928         }
1929     }
1930     // where
1931         private ResultInfo caseLabelResultInfo(Type seltype) {
1932             return new ResultInfo(KindSelector.VAL_TYP,
1933                                   !seltype.hasTag(ERROR) ? seltype
1934                                                          : Type.noType);
1935         }
1936         /** Add any variables defined in stats to the switch scope. */
1937         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
1938             for (;stats.nonEmpty(); stats = stats.tail) {
1939                 JCTree stat = stats.head;
1940                 if (stat.hasTag(VARDEF))
1941                     switchScope.enter(((JCVariableDecl) stat).sym);
1942             }
1943         }
1944     // where
1945     /** Return the selected enumeration constant symbol, or null. */
1946     private Symbol enumConstant(JCTree tree, Type enumType) {
1947         if (tree.hasTag(IDENT)) {
1948             JCIdent ident = (JCIdent)tree;
1949             Name name = ident.name;
1950             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
1951                 if (sym.kind == VAR) {
1952                     Symbol s = ident.sym = sym;
1953                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1954                     ident.type = s.type;
1955                     return ((s.flags_field & Flags.ENUM) == 0)
1956                         ? null : s;
1957                 }
1958             }
1959         }
1960         return null;
1961     }
1962 
1963     public void visitSynchronized(JCSynchronized tree) {
1964         chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
1965         if (tree.lock.type != null && tree.lock.type.isValueBased()) {
1966             log.warning(tree.pos(), LintWarnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
1967         }
1968         attribStat(tree.body, env);
1969         result = null;
1970     }
1971 
1972     public void visitTry(JCTry tree) {
1973         // Create a new local environment with a local
1974         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1975         try {
1976             boolean isTryWithResource = tree.resources.nonEmpty();
1977             // Create a nested environment for attributing the try block if needed
1978             Env<AttrContext> tryEnv = isTryWithResource ?
1979                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1980                 localEnv;
1981             try {
1982                 // Attribute resource declarations
1983                 for (JCTree resource : tree.resources) {
1984                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
1985                         @Override
1986                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
1987                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
1988                         }
1989                     };
1990                     ResultInfo twrResult =
1991                         new ResultInfo(KindSelector.VAR,
1992                                        syms.autoCloseableType,
1993                                        twrContext);
1994                     if (resource.hasTag(VARDEF)) {
1995                         attribStat(resource, tryEnv);
1996                         twrResult.check(resource, resource.type);
1997 
1998                         //check that resource type cannot throw InterruptedException
1999                         checkAutoCloseable(resource.pos(), localEnv, resource.type);
2000 
2001                         VarSymbol var = ((JCVariableDecl) resource).sym;
2002 
2003                         var.flags_field |= Flags.FINAL;
2004                         var.setData(ElementKind.RESOURCE_VARIABLE);
2005                     } else {
2006                         attribTree(resource, tryEnv, twrResult);
2007                     }
2008                 }
2009                 // Attribute body
2010                 attribStat(tree.body, tryEnv);
2011             } finally {
2012                 if (isTryWithResource)
2013                     tryEnv.info.scope.leave();
2014             }
2015 
2016             // Attribute catch clauses
2017             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
2018                 JCCatch c = l.head;
2019                 Env<AttrContext> catchEnv =
2020                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
2021                 try {
2022                     Type ctype = attribStat(c.param, catchEnv);
2023                     if (TreeInfo.isMultiCatch(c)) {
2024                         //multi-catch parameter is implicitly marked as final
2025                         c.param.sym.flags_field |= FINAL | UNION;
2026                     }
2027                     if (c.param.sym.kind == VAR) {
2028                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
2029                     }
2030                     chk.checkType(c.param.vartype.pos(),
2031                                   chk.checkClassType(c.param.vartype.pos(), ctype),
2032                                   syms.throwableType);
2033                     attribStat(c.body, catchEnv);
2034                 } finally {
2035                     catchEnv.info.scope.leave();
2036                 }
2037             }
2038 
2039             // Attribute finalizer
2040             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
2041             result = null;
2042         }
2043         finally {
2044             localEnv.info.scope.leave();
2045         }
2046     }
2047 
2048     void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
2049         if (!resource.isErroneous() &&
2050             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
2051             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
2052             Symbol close = syms.noSymbol;
2053             Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
2054             try {
2055                 close = rs.resolveQualifiedMethod(pos,
2056                         env,
2057                         types.skipTypeVars(resource, false),
2058                         names.close,
2059                         List.nil(),
2060                         List.nil());
2061             }
2062             finally {
2063                 log.popDiagnosticHandler(discardHandler);
2064             }
2065             if (close.kind == MTH &&
2066                     close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
2067                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes())) {
2068                 log.warning(pos, LintWarnings.TryResourceThrowsInterruptedExc(resource));
2069             }
2070         }
2071     }
2072 
2073     public void visitConditional(JCConditional tree) {
2074         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2075         MatchBindings condBindings = matchBindings;
2076 
2077         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2078                 isBooleanOrNumeric(env, tree)) ?
2079                 PolyKind.STANDALONE : PolyKind.POLY;
2080 
2081         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2082             //this means we are returning a poly conditional from void-compatible lambda expression
2083             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2084             result = tree.type = types.createErrorType(resultInfo.pt);
2085             return;
2086         }
2087 
2088         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2089                 unknownExprInfo :
2090                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2091 
2092 
2093         // x ? y : z
2094         // include x's bindings when true in y
2095         // include x's bindings when false in z
2096 
2097         Type truetype;
2098         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2099         try {
2100             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2101         } finally {
2102             trueEnv.info.scope.leave();
2103         }
2104 
2105         MatchBindings trueBindings = matchBindings;
2106 
2107         Type falsetype;
2108         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2109         try {
2110             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2111         } finally {
2112             falseEnv.info.scope.leave();
2113         }
2114 
2115         MatchBindings falseBindings = matchBindings;
2116 
2117         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2118                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2119                          List.of(truetype, falsetype)) : pt();
2120         if (condtype.constValue() != null &&
2121                 truetype.constValue() != null &&
2122                 falsetype.constValue() != null &&
2123                 !owntype.hasTag(NONE)) {
2124             //constant folding
2125             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2126         }
2127         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2128         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2129     }
2130     //where
2131         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2132             switch (tree.getTag()) {
2133                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2134                               ((JCLiteral)tree).typetag == BOOLEAN ||
2135                               ((JCLiteral)tree).typetag == BOT;
2136                 case LAMBDA: case REFERENCE: return false;
2137                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2138                 case CONDEXPR:
2139                     JCConditional condTree = (JCConditional)tree;
2140                     return isBooleanOrNumeric(env, condTree.truepart) &&
2141                             isBooleanOrNumeric(env, condTree.falsepart);
2142                 case APPLY:
2143                     JCMethodInvocation speculativeMethodTree =
2144                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2145                                     tree, env, unknownExprInfo,
2146                                     argumentAttr.withLocalCacheContext());
2147                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2148                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2149                             env.enclClass.type :
2150                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2151                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2152                     return primitiveOrBoxed(owntype);
2153                 case NEWCLASS:
2154                     JCExpression className =
2155                             removeClassParams.translate(((JCNewClass)tree).clazz);
2156                     JCExpression speculativeNewClassTree =
2157                             (JCExpression)deferredAttr.attribSpeculative(
2158                                     className, env, unknownTypeInfo,
2159                                     argumentAttr.withLocalCacheContext());
2160                     return primitiveOrBoxed(speculativeNewClassTree.type);
2161                 default:
2162                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2163                             argumentAttr.withLocalCacheContext()).type;
2164                     return primitiveOrBoxed(speculativeType);
2165             }
2166         }
2167         //where
2168             boolean primitiveOrBoxed(Type t) {
2169                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2170             }
2171 
2172             TreeTranslator removeClassParams = new TreeTranslator() {
2173                 @Override
2174                 public void visitTypeApply(JCTypeApply tree) {
2175                     result = translate(tree.clazz);
2176                 }
2177             };
2178 
2179         CheckContext conditionalContext(CheckContext checkContext) {
2180             return new Check.NestedCheckContext(checkContext) {
2181                 //this will use enclosing check context to check compatibility of
2182                 //subexpression against target type; if we are in a method check context,
2183                 //depending on whether boxing is allowed, we could have incompatibilities
2184                 @Override
2185                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2186                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2187                 }
2188             };
2189         }
2190 
2191         /** Compute the type of a conditional expression, after
2192          *  checking that it exists.  See JLS 15.25. Does not take into
2193          *  account the special case where condition and both arms
2194          *  are constants.
2195          *
2196          *  @param pos      The source position to be used for error
2197          *                  diagnostics.
2198          *  @param thentype The type of the expression's then-part.
2199          *  @param elsetype The type of the expression's else-part.
2200          */
2201         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2202             if (condTypes.isEmpty()) {
2203                 return syms.objectType; //TODO: how to handle?
2204             }
2205             Type first = condTypes.head;
2206             // If same type, that is the result
2207             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2208                 return first.baseType();
2209 
2210             List<Type> unboxedTypes = condTypes.stream()
2211                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2212                                                .collect(List.collector());
2213 
2214             // Otherwise, if both arms can be converted to a numeric
2215             // type, return the least numeric type that fits both arms
2216             // (i.e. return larger of the two, or return int if one
2217             // arm is short, the other is char).
2218             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2219                 // If one arm has an integer subrange type (i.e., byte,
2220                 // short, or char), and the other is an integer constant
2221                 // that fits into the subrange, return the subrange type.
2222                 for (Type type : unboxedTypes) {
2223                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2224                         continue;
2225                     }
2226                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2227                         return type.baseType();
2228                 }
2229 
2230                 for (TypeTag tag : primitiveTags) {
2231                     Type candidate = syms.typeOfTag[tag.ordinal()];
2232                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2233                         return candidate;
2234                     }
2235                 }
2236             }
2237 
2238             // Those were all the cases that could result in a primitive
2239             condTypes = condTypes.stream()
2240                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
2241                                  .collect(List.collector());
2242 
2243             for (Type type : condTypes) {
2244                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2245                     return type.baseType();
2246             }
2247 
2248             Iterator<DiagnosticPosition> posIt = positions.iterator();
2249 
2250             condTypes = condTypes.stream()
2251                                  .map(t -> chk.checkNonVoid(posIt.next(), t))
2252                                  .collect(List.collector());
2253 
2254             // both are known to be reference types.  The result is
2255             // lub(thentype,elsetype). This cannot fail, as it will
2256             // always be possible to infer "Object" if nothing better.
2257             return types.lub(condTypes.stream()
2258                         .map(t -> t.baseType())
2259                         .filter(t -> !t.hasTag(BOT))
2260                         .collect(List.collector()));
2261         }
2262 
2263     static final TypeTag[] primitiveTags = new TypeTag[]{
2264         BYTE,
2265         CHAR,
2266         SHORT,
2267         INT,
2268         LONG,
2269         FLOAT,
2270         DOUBLE,
2271         BOOLEAN,
2272     };
2273 
2274     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2275         return bindingEnv(env, env.tree, bindings);
2276     }
2277 
2278     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2279         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2280         bindings.forEach(env1.info.scope::enter);
2281         return env1;
2282     }
2283 
2284     public void visitIf(JCIf tree) {
2285         attribExpr(tree.cond, env, syms.booleanType);
2286 
2287         // if (x) { y } [ else z ]
2288         // include x's bindings when true in y
2289         // include x's bindings when false in z
2290 
2291         MatchBindings condBindings = matchBindings;
2292         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2293 
2294         try {
2295             attribStat(tree.thenpart, thenEnv);
2296         } finally {
2297             thenEnv.info.scope.leave();
2298         }
2299 
2300         preFlow(tree.thenpart);
2301         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2302         boolean aliveAfterElse;
2303 
2304         if (tree.elsepart != null) {
2305             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2306             try {
2307                 attribStat(tree.elsepart, elseEnv);
2308             } finally {
2309                 elseEnv.info.scope.leave();
2310             }
2311             preFlow(tree.elsepart);
2312             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2313         } else {
2314             aliveAfterElse = true;
2315         }
2316 
2317         chk.checkEmptyIf(tree);
2318 
2319         List<BindingSymbol> afterIfBindings = List.nil();
2320 
2321         if (aliveAfterThen && !aliveAfterElse) {
2322             afterIfBindings = condBindings.bindingsWhenTrue;
2323         } else if (aliveAfterElse && !aliveAfterThen) {
2324             afterIfBindings = condBindings.bindingsWhenFalse;
2325         }
2326 
2327         addBindings2Scope(tree, afterIfBindings);
2328 
2329         result = null;
2330     }
2331 
2332         void preFlow(JCTree tree) {
2333             attrRecover.doRecovery();
2334             new PostAttrAnalyzer() {
2335                 @Override
2336                 public void scan(JCTree tree) {
2337                     if (tree == null ||
2338                             (tree.type != null &&
2339                             tree.type == Type.stuckType)) {
2340                         //don't touch stuck expressions!
2341                         return;
2342                     }
2343                     super.scan(tree);
2344                 }
2345 
2346                 @Override
2347                 public void visitClassDef(JCClassDecl that) {
2348                     if (that.sym != null) {
2349                         // Method preFlow shouldn't visit class definitions
2350                         // that have not been entered and attributed.
2351                         // See JDK-8254557 and JDK-8203277 for more details.
2352                         super.visitClassDef(that);
2353                     }
2354                 }
2355 
2356                 @Override
2357                 public void visitLambda(JCLambda that) {
2358                     if (that.type != null) {
2359                         // Method preFlow shouldn't visit lambda expressions
2360                         // that have not been entered and attributed.
2361                         // See JDK-8254557 and JDK-8203277 for more details.
2362                         super.visitLambda(that);
2363                     }
2364                 }
2365             }.scan(tree);
2366         }
2367 
2368     public void visitExec(JCExpressionStatement tree) {
2369         //a fresh environment is required for 292 inference to work properly ---
2370         //see Infer.instantiatePolymorphicSignatureInstance()
2371         Env<AttrContext> localEnv = env.dup(tree);
2372         attribExpr(tree.expr, localEnv);
2373         result = null;
2374     }
2375 
2376     public void visitBreak(JCBreak tree) {
2377         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2378         result = null;
2379     }
2380 
2381     public void visitYield(JCYield tree) {
2382         if (env.info.yieldResult != null) {
2383             attribTree(tree.value, env, env.info.yieldResult);
2384             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2385         } else {
2386             log.error(tree.pos(), tree.value.hasTag(PARENS)
2387                     ? Errors.NoSwitchExpressionQualify
2388                     : Errors.NoSwitchExpression);
2389             attribTree(tree.value, env, unknownExprInfo);
2390         }
2391         result = null;
2392     }
2393 
2394     public void visitContinue(JCContinue tree) {
2395         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2396         result = null;
2397     }
2398     //where
2399         /** Return the target of a break, continue or yield statement,
2400          *  if it exists, report an error if not.
2401          *  Note: The target of a labelled break or continue is the
2402          *  (non-labelled) statement tree referred to by the label,
2403          *  not the tree representing the labelled statement itself.
2404          *
2405          *  @param pos     The position to be used for error diagnostics
2406          *  @param tag     The tag of the jump statement. This is either
2407          *                 Tree.BREAK or Tree.CONTINUE.
2408          *  @param label   The label of the jump statement, or null if no
2409          *                 label is given.
2410          *  @param env     The environment current at the jump statement.
2411          */
2412         private JCTree findJumpTarget(DiagnosticPosition pos,
2413                                                    JCTree.Tag tag,
2414                                                    Name label,
2415                                                    Env<AttrContext> env) {
2416             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2417 
2418             if (jumpTarget.snd != null) {
2419                 log.error(pos, jumpTarget.snd);
2420             }
2421 
2422             return jumpTarget.fst;
2423         }
2424         /** Return the target of a break or continue statement, if it exists,
2425          *  report an error if not.
2426          *  Note: The target of a labelled break or continue is the
2427          *  (non-labelled) statement tree referred to by the label,
2428          *  not the tree representing the labelled statement itself.
2429          *
2430          *  @param tag     The tag of the jump statement. This is either
2431          *                 Tree.BREAK or Tree.CONTINUE.
2432          *  @param label   The label of the jump statement, or null if no
2433          *                 label is given.
2434          *  @param env     The environment current at the jump statement.
2435          */
2436         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2437                                                                        Name label,
2438                                                                        Env<AttrContext> env) {
2439             // Search environments outwards from the point of jump.
2440             Env<AttrContext> env1 = env;
2441             JCDiagnostic.Error pendingError = null;
2442             LOOP:
2443             while (env1 != null) {
2444                 switch (env1.tree.getTag()) {
2445                     case LABELLED:
2446                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2447                         if (label == labelled.label) {
2448                             // If jump is a continue, check that target is a loop.
2449                             if (tag == CONTINUE) {
2450                                 if (!labelled.body.hasTag(DOLOOP) &&
2451                                         !labelled.body.hasTag(WHILELOOP) &&
2452                                         !labelled.body.hasTag(FORLOOP) &&
2453                                         !labelled.body.hasTag(FOREACHLOOP)) {
2454                                     pendingError = Errors.NotLoopLabel(label);
2455                                 }
2456                                 // Found labelled statement target, now go inwards
2457                                 // to next non-labelled tree.
2458                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2459                             } else {
2460                                 return Pair.of(labelled, pendingError);
2461                             }
2462                         }
2463                         break;
2464                     case DOLOOP:
2465                     case WHILELOOP:
2466                     case FORLOOP:
2467                     case FOREACHLOOP:
2468                         if (label == null) return Pair.of(env1.tree, pendingError);
2469                         break;
2470                     case SWITCH:
2471                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2472                         break;
2473                     case SWITCH_EXPRESSION:
2474                         if (tag == YIELD) {
2475                             return Pair.of(env1.tree, null);
2476                         } else if (tag == BREAK) {
2477                             pendingError = Errors.BreakOutsideSwitchExpression;
2478                         } else {
2479                             pendingError = Errors.ContinueOutsideSwitchExpression;
2480                         }
2481                         break;
2482                     case LAMBDA:
2483                     case METHODDEF:
2484                     case CLASSDEF:
2485                         break LOOP;
2486                     default:
2487                 }
2488                 env1 = env1.next;
2489             }
2490             if (label != null)
2491                 return Pair.of(null, Errors.UndefLabel(label));
2492             else if (pendingError != null)
2493                 return Pair.of(null, pendingError);
2494             else if (tag == CONTINUE)
2495                 return Pair.of(null, Errors.ContOutsideLoop);
2496             else
2497                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2498         }
2499 
2500     public void visitReturn(JCReturn tree) {
2501         // Check that there is an enclosing method which is
2502         // nested within than the enclosing class.
2503         if (env.info.returnResult == null) {
2504             log.error(tree.pos(), Errors.RetOutsideMeth);
2505         } else if (env.info.yieldResult != null) {
2506             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2507             if (tree.expr != null) {
2508                 attribExpr(tree.expr, env, env.info.yieldResult.pt);
2509             }
2510         } else if (!env.info.isLambda &&
2511                 env.enclMethod != null &&
2512                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2513             log.error(env.enclMethod,
2514                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2515         } else {
2516             // Attribute return expression, if it exists, and check that
2517             // it conforms to result type of enclosing method.
2518             if (tree.expr != null) {
2519                 if (env.info.returnResult.pt.hasTag(VOID)) {
2520                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2521                               diags.fragment(Fragments.UnexpectedRetVal));
2522                 }
2523                 attribTree(tree.expr, env, env.info.returnResult);
2524             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2525                     !env.info.returnResult.pt.hasTag(NONE)) {
2526                 env.info.returnResult.checkContext.report(tree.pos(),
2527                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2528             }
2529         }
2530         result = null;
2531     }
2532 
2533     public void visitThrow(JCThrow tree) {
2534         Type owntype = attribExpr(tree.expr, env, Type.noType);
2535         chk.checkType(tree, owntype, syms.throwableType);
2536         result = null;
2537     }
2538 
2539     public void visitAssert(JCAssert tree) {
2540         attribExpr(tree.cond, env, syms.booleanType);
2541         if (tree.detail != null) {
2542             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2543         }
2544         result = null;
2545     }
2546 
2547      /** Visitor method for method invocations.
2548      *  NOTE: The method part of an application will have in its type field
2549      *        the return type of the method, not the method's type itself!
2550      */
2551     public void visitApply(JCMethodInvocation tree) {
2552         // The local environment of a method application is
2553         // a new environment nested in the current one.
2554         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2555 
2556         // The types of the actual method arguments.
2557         List<Type> argtypes;
2558 
2559         // The types of the actual method type arguments.
2560         List<Type> typeargtypes = null;
2561 
2562         Name methName = TreeInfo.name(tree.meth);
2563 
2564         boolean isConstructorCall =
2565             methName == names._this || methName == names._super;
2566 
2567         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2568         if (isConstructorCall) {
2569 
2570             // Attribute arguments, yielding list of argument types.
2571             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2572             argtypes = argtypesBuf.toList();
2573             typeargtypes = attribTypes(tree.typeargs, localEnv);
2574 
2575             // Done with this()/super() parameters. End of constructor prologue.
2576             env.info.ctorPrologue = false;
2577 
2578             // Variable `site' points to the class in which the called
2579             // constructor is defined.
2580             Type site = env.enclClass.sym.type;
2581             if (methName == names._super) {
2582                 if (site == syms.objectType) {
2583                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2584                     site = types.createErrorType(syms.objectType);
2585                 } else {
2586                     site = types.supertype(site);
2587                 }
2588             }
2589 
2590             if (site.hasTag(CLASS)) {
2591                 Type encl = site.getEnclosingType();
2592                 while (encl != null && encl.hasTag(TYPEVAR))
2593                     encl = encl.getUpperBound();
2594                 if (encl.hasTag(CLASS)) {
2595                     // we are calling a nested class
2596 
2597                     if (tree.meth.hasTag(SELECT)) {
2598                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2599 
2600                         // We are seeing a prefixed call, of the form
2601                         //     <expr>.super(...).
2602                         // Check that the prefix expression conforms
2603                         // to the outer instance type of the class.
2604                         chk.checkRefType(qualifier.pos(),
2605                                          attribExpr(qualifier, localEnv,
2606                                                     encl));
2607                     }
2608                 } else if (tree.meth.hasTag(SELECT)) {
2609                     log.error(tree.meth.pos(),
2610                               Errors.IllegalQualNotIcls(site.tsym));
2611                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2612                 }
2613 
2614                 if (tree.meth.hasTag(IDENT)) {
2615                     // non-qualified super(...) call; check whether explicit constructor
2616                     // invocation is well-formed. If the super class is an inner class,
2617                     // make sure that an appropriate implicit qualifier exists. If the super
2618                     // class is a local class, make sure that the current class is defined
2619                     // in the same context as the local class.
2620                     checkNewInnerClass(tree.meth.pos(), localEnv, site, true);
2621                 }
2622 
2623                 // if we're calling a java.lang.Enum constructor,
2624                 // prefix the implicit String and int parameters
2625                 if (site.tsym == syms.enumSym)
2626                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
2627 
2628                 // Resolve the called constructor under the assumption
2629                 // that we are referring to a superclass instance of the
2630                 // current instance (JLS ???).
2631                 boolean selectSuperPrev = localEnv.info.selectSuper;
2632                 localEnv.info.selectSuper = true;
2633                 localEnv.info.pendingResolutionPhase = null;
2634                 Symbol sym = rs.resolveConstructor(
2635                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
2636                 localEnv.info.selectSuper = selectSuperPrev;
2637 
2638                 // Set method symbol to resolved constructor...
2639                 TreeInfo.setSymbol(tree.meth, sym);
2640 
2641                 // ...and check that it is legal in the current context.
2642                 // (this will also set the tree's type)
2643                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2644                 checkId(tree.meth, site, sym, localEnv,
2645                         new ResultInfo(kind, mpt));
2646             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
2647                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2648             }
2649             // Otherwise, `site' is an error type and we do nothing
2650             result = tree.type = syms.voidType;
2651         } else {
2652             // Otherwise, we are seeing a regular method call.
2653             // Attribute the arguments, yielding list of argument types, ...
2654             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2655             argtypes = argtypesBuf.toList();
2656             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
2657 
2658             // ... and attribute the method using as a prototype a methodtype
2659             // whose formal argument types is exactly the list of actual
2660             // arguments (this will also set the method symbol).
2661             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2662             localEnv.info.pendingResolutionPhase = null;
2663             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
2664 
2665             // Compute the result type.
2666             Type restype = mtype.getReturnType();
2667             if (restype.hasTag(WILDCARD))
2668                 throw new AssertionError(mtype);
2669 
2670             Type qualifier = (tree.meth.hasTag(SELECT))
2671                     ? ((JCFieldAccess) tree.meth).selected.type
2672                     : env.enclClass.sym.type;
2673             Symbol msym = TreeInfo.symbol(tree.meth);
2674             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
2675 
2676             chk.checkRefTypes(tree.typeargs, typeargtypes);
2677 
2678             // Check that value of resulting type is admissible in the
2679             // current context.  Also, capture the return type
2680             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
2681             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
2682         }
2683         chk.checkRequiresIdentity(tree, env.info.lint);
2684         chk.validate(tree.typeargs, localEnv);
2685     }
2686     //where
2687         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
2688             if (msym != null &&
2689                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
2690                     methodName == names.getClass &&
2691                     argtypes.isEmpty()) {
2692                 // as a special case, x.getClass() has type Class<? extends |X|>
2693                 return new ClassType(restype.getEnclosingType(),
2694                         List.of(new WildcardType(types.erasure(qualifierType.baseType()),
2695                                 BoundKind.EXTENDS,
2696                                 syms.boundClass)),
2697                         restype.tsym,
2698                         restype.getMetadata());
2699             } else if (msym != null &&
2700                     msym.owner == syms.arrayClass &&
2701                     methodName == names.clone &&
2702                     types.isArray(qualifierType)) {
2703                 // as a special case, array.clone() has a result that is
2704                 // the same as static type of the array being cloned
2705                 return qualifierType;
2706             } else {
2707                 return restype;
2708             }
2709         }
2710 
2711         /** Obtain a method type with given argument types.
2712          */
2713         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
2714             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
2715             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
2716         }
2717 
2718     public void visitNewClass(final JCNewClass tree) {
2719         Type owntype = types.createErrorType(tree.type);
2720 
2721         // The local environment of a class creation is
2722         // a new environment nested in the current one.
2723         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2724 
2725         // The anonymous inner class definition of the new expression,
2726         // if one is defined by it.
2727         JCClassDecl cdef = tree.def;
2728 
2729         // If enclosing class is given, attribute it, and
2730         // complete class name to be fully qualified
2731         JCExpression clazz = tree.clazz; // Class field following new
2732         JCExpression clazzid;            // Identifier in class field
2733         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
2734         annoclazzid = null;
2735 
2736         if (clazz.hasTag(TYPEAPPLY)) {
2737             clazzid = ((JCTypeApply) clazz).clazz;
2738             if (clazzid.hasTag(ANNOTATED_TYPE)) {
2739                 annoclazzid = (JCAnnotatedType) clazzid;
2740                 clazzid = annoclazzid.underlyingType;
2741             }
2742         } else {
2743             if (clazz.hasTag(ANNOTATED_TYPE)) {
2744                 annoclazzid = (JCAnnotatedType) clazz;
2745                 clazzid = annoclazzid.underlyingType;
2746             } else {
2747                 clazzid = clazz;
2748             }
2749         }
2750 
2751         JCExpression clazzid1 = clazzid; // The same in fully qualified form
2752 
2753         if (tree.encl != null) {
2754             // We are seeing a qualified new, of the form
2755             //    <expr>.new C <...> (...) ...
2756             // In this case, we let clazz stand for the name of the
2757             // allocated class C prefixed with the type of the qualifier
2758             // expression, so that we can
2759             // resolve it with standard techniques later. I.e., if
2760             // <expr> has type T, then <expr>.new C <...> (...)
2761             // yields a clazz T.C.
2762             Type encltype = chk.checkRefType(tree.encl.pos(),
2763                                              attribExpr(tree.encl, env));
2764             // TODO 308: in <expr>.new C, do we also want to add the type annotations
2765             // from expr to the combined type, or not? Yes, do this.
2766             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
2767                                                  ((JCIdent) clazzid).name);
2768 
2769             EndPosTable endPosTable = this.env.toplevel.endPositions;
2770             endPosTable.storeEnd(clazzid1, clazzid.getEndPosition(endPosTable));
2771             if (clazz.hasTag(ANNOTATED_TYPE)) {
2772                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
2773                 List<JCAnnotation> annos = annoType.annotations;
2774 
2775                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
2776                     clazzid1 = make.at(tree.pos).
2777                         TypeApply(clazzid1,
2778                                   ((JCTypeApply) clazz).arguments);
2779                 }
2780 
2781                 clazzid1 = make.at(tree.pos).
2782                     AnnotatedType(annos, clazzid1);
2783             } else if (clazz.hasTag(TYPEAPPLY)) {
2784                 clazzid1 = make.at(tree.pos).
2785                     TypeApply(clazzid1,
2786                               ((JCTypeApply) clazz).arguments);
2787             }
2788 
2789             clazz = clazzid1;
2790         }
2791 
2792         // Attribute clazz expression and store
2793         // symbol + type back into the attributed tree.
2794         Type clazztype = TreeInfo.isEnumInit(env.tree) ?
2795             attribIdentAsEnumType(env, (JCIdent)clazz) :
2796             attribType(clazz, env);
2797 
2798         clazztype = chk.checkDiamond(tree, clazztype);
2799         chk.validate(clazz, localEnv);
2800         if (tree.encl != null) {
2801             // We have to work in this case to store
2802             // symbol + type back into the attributed tree.
2803             tree.clazz.type = clazztype;
2804             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
2805             clazzid.type = ((JCIdent) clazzid).sym.type;
2806             if (annoclazzid != null) {
2807                 annoclazzid.type = clazzid.type;
2808             }
2809             if (!clazztype.isErroneous()) {
2810                 if (cdef != null && clazztype.tsym.isInterface()) {
2811                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
2812                 } else if (clazztype.tsym.isStatic()) {
2813                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
2814                 }
2815             }
2816         } else {
2817             // Check for the existence of an apropos outer instance
2818             checkNewInnerClass(tree.pos(), env, clazztype, false);
2819         }
2820 
2821         // Attribute constructor arguments.
2822         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2823         final KindSelector pkind =
2824             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2825         List<Type> argtypes = argtypesBuf.toList();
2826         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
2827 
2828         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
2829             // Enums may not be instantiated except implicitly
2830             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
2831                 (!env.tree.hasTag(VARDEF) ||
2832                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
2833                  ((JCVariableDecl) env.tree).init != tree))
2834                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
2835 
2836             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
2837                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
2838             boolean skipNonDiamondPath = false;
2839             // Check that class is not abstract
2840             if (cdef == null && !tree.classDeclRemoved() && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
2841                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
2842                 log.error(tree.pos(),
2843                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
2844                 skipNonDiamondPath = true;
2845             } else if (cdef != null && clazztype.tsym.isInterface()) {
2846                 // Check that no constructor arguments are given to
2847                 // anonymous classes implementing an interface
2848                 if (!argtypes.isEmpty())
2849                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
2850 
2851                 if (!typeargtypes.isEmpty())
2852                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
2853 
2854                 // Error recovery: pretend no arguments were supplied.
2855                 argtypes = List.nil();
2856                 typeargtypes = List.nil();
2857                 skipNonDiamondPath = true;
2858             }
2859             if (TreeInfo.isDiamond(tree)) {
2860                 ClassType site = new ClassType(clazztype.getEnclosingType(),
2861                             clazztype.tsym.type.getTypeArguments(),
2862                                                clazztype.tsym,
2863                                                clazztype.getMetadata());
2864 
2865                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
2866                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
2867                 diamondEnv.info.pendingResolutionPhase = null;
2868 
2869                 //if the type of the instance creation expression is a class type
2870                 //apply method resolution inference (JLS 15.12.2.7). The return type
2871                 //of the resolved constructor will be a partially instantiated type
2872                 Symbol constructor = rs.resolveDiamond(tree.pos(),
2873                             diamondEnv,
2874                             site,
2875                             argtypes,
2876                             typeargtypes);
2877                 tree.constructor = constructor.baseSymbol();
2878 
2879                 final TypeSymbol csym = clazztype.tsym;
2880                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
2881                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
2882                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
2883                 constructorType = checkId(tree, site,
2884                         constructor,
2885                         diamondEnv,
2886                         diamondResult);
2887 
2888                 tree.clazz.type = types.createErrorType(clazztype);
2889                 if (!constructorType.isErroneous()) {
2890                     tree.clazz.type = clazz.type = constructorType.getReturnType();
2891                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
2892                 }
2893                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
2894             }
2895 
2896             // Resolve the called constructor under the assumption
2897             // that we are referring to a superclass instance of the
2898             // current instance (JLS ???).
2899             else if (!skipNonDiamondPath) {
2900                 //the following code alters some of the fields in the current
2901                 //AttrContext - hence, the current context must be dup'ed in
2902                 //order to avoid downstream failures
2903                 Env<AttrContext> rsEnv = localEnv.dup(tree);
2904                 rsEnv.info.selectSuper = cdef != null;
2905                 rsEnv.info.pendingResolutionPhase = null;
2906                 tree.constructor = rs.resolveConstructor(
2907                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
2908                 if (cdef == null) { //do not check twice!
2909                     tree.constructorType = checkId(tree,
2910                             clazztype,
2911                             tree.constructor,
2912                             rsEnv,
2913                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
2914                     if (rsEnv.info.lastResolveVarargs())
2915                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
2916                 }
2917             }
2918 
2919             chk.checkRequiresIdentity(tree, env.info.lint);
2920 
2921             if (cdef != null) {
2922                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
2923                 return;
2924             }
2925 
2926             if (tree.constructor != null && tree.constructor.kind == MTH)
2927                 owntype = clazztype;
2928         }
2929         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2930         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2931         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
2932             //we need to wait for inference to finish and then replace inference vars in the constructor type
2933             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
2934                     instantiatedContext -> {
2935                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2936                     });
2937         }
2938         chk.validate(tree.typeargs, localEnv);
2939     }
2940 
2941         // where
2942         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
2943                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
2944                                                    List<Type> argtypes, List<Type> typeargtypes,
2945                                                    KindSelector pkind) {
2946             // We are seeing an anonymous class instance creation.
2947             // In this case, the class instance creation
2948             // expression
2949             //
2950             //    E.new <typeargs1>C<typargs2>(args) { ... }
2951             //
2952             // is represented internally as
2953             //
2954             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
2955             //
2956             // This expression is then *transformed* as follows:
2957             //
2958             // (1) add an extends or implements clause
2959             // (2) add a constructor.
2960             //
2961             // For instance, if C is a class, and ET is the type of E,
2962             // the expression
2963             //
2964             //    E.new <typeargs1>C<typargs2>(args) { ... }
2965             //
2966             // is translated to (where X is a fresh name and typarams is the
2967             // parameter list of the super constructor):
2968             //
2969             //   new <typeargs1>X(<*nullchk*>E, args) where
2970             //     X extends C<typargs2> {
2971             //       <typarams> X(ET e, args) {
2972             //         e.<typeargs1>super(args)
2973             //       }
2974             //       ...
2975             //     }
2976             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2977             Type enclType = clazztype.getEnclosingType();
2978             if (enclType != null &&
2979                     enclType.hasTag(CLASS) &&
2980                     !chk.checkDenotable((ClassType)enclType)) {
2981                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
2982             }
2983             final boolean isDiamond = TreeInfo.isDiamond(tree);
2984             if (isDiamond
2985                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
2986                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
2987                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
2988                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
2989                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
2990                         instantiatedContext -> {
2991                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2992                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
2993                             ResultInfo prevResult = this.resultInfo;
2994                             try {
2995                                 this.resultInfo = resultInfoForClassDefinition;
2996                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
2997                                         dupLocalEnv, argtypes, typeargtypes, pkind);
2998                             } finally {
2999                                 this.resultInfo = prevResult;
3000                             }
3001                         });
3002             } else {
3003                 if (isDiamond && clazztype.hasTag(CLASS)) {
3004                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
3005                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
3006                         // One or more types inferred in the previous steps is non-denotable.
3007                         Fragment fragment = Diamond(clazztype.tsym);
3008                         log.error(tree.clazz.pos(),
3009                                 Errors.CantApplyDiamond1(
3010                                         fragment,
3011                                         invalidDiamondArgs.size() > 1 ?
3012                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
3013                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
3014                     }
3015                     // For <>(){}, inferred types must also be accessible.
3016                     for (Type t : clazztype.getTypeArguments()) {
3017                         rs.checkAccessibleType(env, t);
3018                     }
3019                 }
3020 
3021                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
3022                 // false for isInterface call even when the original type is an interface.
3023                 boolean implementing = clazztype.tsym.isInterface() ||
3024                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
3025                         clazztype.getOriginalType().tsym.isInterface();
3026 
3027                 if (implementing) {
3028                     cdef.implementing = List.of(clazz);
3029                 } else {
3030                     cdef.extending = clazz;
3031                 }
3032 
3033                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3034                     rs.isSerializable(clazztype)) {
3035                     localEnv.info.isSerializable = true;
3036                 }
3037 
3038                 attribStat(cdef, localEnv);
3039 
3040                 List<Type> finalargtypes;
3041                 // If an outer instance is given,
3042                 // prefix it to the constructor arguments
3043                 // and delete it from the new expression
3044                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
3045                     finalargtypes = argtypes.prepend(tree.encl.type);
3046                 } else {
3047                     finalargtypes = argtypes;
3048                 }
3049 
3050                 // Reassign clazztype and recompute constructor. As this necessarily involves
3051                 // another attribution pass for deferred types in the case of <>, replicate
3052                 // them. Original arguments have right decorations already.
3053                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3054                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3055                 }
3056 
3057                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3058                                                     : cdef.sym.type;
3059                 Symbol sym = tree.constructor = rs.resolveConstructor(
3060                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3061                 Assert.check(!sym.kind.isResolutionError());
3062                 tree.constructor = sym;
3063                 tree.constructorType = checkId(tree,
3064                         clazztype,
3065                         tree.constructor,
3066                         localEnv,
3067                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3068             }
3069             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3070                                 clazztype : types.createErrorType(tree.type);
3071             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3072             chk.validate(tree.typeargs, localEnv);
3073         }
3074 
3075         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3076             return new Check.NestedCheckContext(checkContext) {
3077                 @Override
3078                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3079                     enclosingContext.report(clazz.clazz,
3080                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3081                 }
3082             };
3083         }
3084 
3085         void checkNewInnerClass(DiagnosticPosition pos, Env<AttrContext> env, Type type, boolean isSuper) {
3086             boolean isLocal = type.tsym.owner.kind == VAR || type.tsym.owner.kind == MTH;
3087             if ((type.tsym.flags() & (INTERFACE | ENUM | RECORD)) != 0 ||
3088                     (!isLocal && !type.tsym.isInner()) ||
3089                     (isSuper && env.enclClass.sym.isAnonymous())) {
3090                 // nothing to check
3091                 return;
3092             }
3093             Symbol res = isLocal ?
3094                     rs.findLocalClassOwner(env, type.tsym) :
3095                     rs.findSelfContaining(pos, env, type.getEnclosingType().tsym, isSuper);
3096             if (res.exists()) {
3097                 rs.accessBase(res, pos, env.enclClass.sym.type, names._this, true);
3098             } else {
3099                 log.error(pos, Errors.EnclClassRequired(type.tsym));
3100             }
3101         }
3102 
3103     /** Make an attributed null check tree.
3104      */
3105     public JCExpression makeNullCheck(JCExpression arg) {
3106         // optimization: new Outer() can never be null; skip null check
3107         if (arg.getTag() == NEWCLASS)
3108             return arg;
3109         // optimization: X.this is never null; skip null check
3110         Name name = TreeInfo.name(arg);
3111         if (name == names._this || name == names._super) return arg;
3112 
3113         JCTree.Tag optag = NULLCHK;
3114         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3115         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3116         tree.type = arg.type;
3117         return tree;
3118     }
3119 
3120     public void visitNewArray(JCNewArray tree) {
3121         Type owntype = types.createErrorType(tree.type);
3122         Env<AttrContext> localEnv = env.dup(tree);
3123         Type elemtype;
3124         if (tree.elemtype != null) {
3125             elemtype = attribType(tree.elemtype, localEnv);
3126             chk.validate(tree.elemtype, localEnv);
3127             owntype = elemtype;
3128             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3129                 attribExpr(l.head, localEnv, syms.intType);
3130                 owntype = new ArrayType(owntype, syms.arrayClass);
3131             }
3132         } else {
3133             // we are seeing an untyped aggregate { ... }
3134             // this is allowed only if the prototype is an array
3135             if (pt().hasTag(ARRAY)) {
3136                 elemtype = types.elemtype(pt());
3137             } else {
3138                 if (!pt().hasTag(ERROR) &&
3139                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3140                     log.error(tree.pos(),
3141                               Errors.IllegalInitializerForType(pt()));
3142                 }
3143                 elemtype = types.createErrorType(pt());
3144             }
3145         }
3146         if (tree.elems != null) {
3147             attribExprs(tree.elems, localEnv, elemtype);
3148             owntype = new ArrayType(elemtype, syms.arrayClass);
3149         }
3150         if (!types.isReifiable(elemtype))
3151             log.error(tree.pos(), Errors.GenericArrayCreation);
3152         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3153     }
3154 
3155     /*
3156      * A lambda expression can only be attributed when a target-type is available.
3157      * In addition, if the target-type is that of a functional interface whose
3158      * descriptor contains inference variables in argument position the lambda expression
3159      * is 'stuck' (see DeferredAttr).
3160      */
3161     @Override
3162     public void visitLambda(final JCLambda that) {
3163         boolean wrongContext = false;
3164         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3165             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3166                 //lambda only allowed in assignment or method invocation/cast context
3167                 log.error(that.pos(), Errors.UnexpectedLambda);
3168             }
3169             resultInfo = recoveryInfo;
3170             wrongContext = true;
3171         }
3172         //create an environment for attribution of the lambda expression
3173         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3174         boolean needsRecovery =
3175                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3176         try {
3177             if (needsRecovery && rs.isSerializable(pt())) {
3178                 localEnv.info.isSerializable = true;
3179                 localEnv.info.isSerializableLambda = true;
3180             }
3181             List<Type> explicitParamTypes = null;
3182             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3183                 //attribute lambda parameters
3184                 attribStats(that.params, localEnv);
3185                 explicitParamTypes = TreeInfo.types(that.params);
3186             }
3187 
3188             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3189             Type currentTarget = targetInfo.target;
3190             Type lambdaType = targetInfo.descriptor;
3191 
3192             if (currentTarget.isErroneous()) {
3193                 result = that.type = currentTarget;
3194                 return;
3195             }
3196 
3197             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3198 
3199             if (lambdaType.hasTag(FORALL)) {
3200                 //lambda expression target desc cannot be a generic method
3201                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3202                                                                     kindName(currentTarget.tsym),
3203                                                                     currentTarget.tsym);
3204                 resultInfo.checkContext.report(that, diags.fragment(msg));
3205                 result = that.type = types.createErrorType(pt());
3206                 return;
3207             }
3208 
3209             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3210                 //add param type info in the AST
3211                 List<Type> actuals = lambdaType.getParameterTypes();
3212                 List<JCVariableDecl> params = that.params;
3213 
3214                 boolean arityMismatch = false;
3215 
3216                 while (params.nonEmpty()) {
3217                     if (actuals.isEmpty()) {
3218                         //not enough actuals to perform lambda parameter inference
3219                         arityMismatch = true;
3220                     }
3221                     //reset previously set info
3222                     Type argType = arityMismatch ?
3223                             syms.errType :
3224                             actuals.head;
3225                     if (params.head.isImplicitlyTyped()) {
3226                         setSyntheticVariableType(params.head, argType);
3227                     }
3228                     params.head.sym = null;
3229                     actuals = actuals.isEmpty() ?
3230                             actuals :
3231                             actuals.tail;
3232                     params = params.tail;
3233                 }
3234 
3235                 //attribute lambda parameters
3236                 attribStats(that.params, localEnv);
3237 
3238                 if (arityMismatch) {
3239                     resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3240                         result = that.type = types.createErrorType(currentTarget);
3241                         return;
3242                 }
3243             }
3244 
3245             //from this point on, no recovery is needed; if we are in assignment context
3246             //we will be able to attribute the whole lambda body, regardless of errors;
3247             //if we are in a 'check' method context, and the lambda is not compatible
3248             //with the target-type, it will be recovered anyway in Attr.checkId
3249             needsRecovery = false;
3250 
3251             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3252                     lambdaBodyResult(that, lambdaType, resultInfo);
3253 
3254             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3255                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3256             } else {
3257                 JCBlock body = (JCBlock)that.body;
3258                 if (body == breakTree &&
3259                         resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3260                     breakTreeFound(copyEnv(localEnv));
3261                 }
3262                 attribStats(body.stats, localEnv);
3263             }
3264 
3265             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3266 
3267             boolean isSpeculativeRound =
3268                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3269 
3270             preFlow(that);
3271             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3272 
3273             that.type = currentTarget; //avoids recovery at this stage
3274             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
3275 
3276             if (!isSpeculativeRound) {
3277                 //add thrown types as bounds to the thrown types free variables if needed:
3278                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3279                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3280                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3281                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3282                     }
3283                 }
3284 
3285                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3286             }
3287             result = wrongContext ? that.type = types.createErrorType(pt())
3288                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3289         } catch (Types.FunctionDescriptorLookupError ex) {
3290             JCDiagnostic cause = ex.getDiagnostic();
3291             resultInfo.checkContext.report(that, cause);
3292             result = that.type = types.createErrorType(pt());
3293             return;
3294         } catch (CompletionFailure cf) {
3295             chk.completionError(that.pos(), cf);
3296         } catch (Throwable t) {
3297             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3298             //as that would likely cause the same exception again.
3299             needsRecovery = false;
3300             throw t;
3301         } finally {
3302             localEnv.info.scope.leave();
3303             if (needsRecovery) {
3304                 Type prevResult = result;
3305                 try {
3306                     attribTree(that, env, recoveryInfo);
3307                 } finally {
3308                     if (result == Type.recoveryType) {
3309                         result = prevResult;
3310                     }
3311                 }
3312             }
3313         }
3314     }
3315     //where
3316         class TargetInfo {
3317             Type target;
3318             Type descriptor;
3319 
3320             public TargetInfo(Type target, Type descriptor) {
3321                 this.target = target;
3322                 this.descriptor = descriptor;
3323             }
3324         }
3325 
3326         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3327             Type lambdaType;
3328             Type currentTarget = resultInfo.pt;
3329             if (resultInfo.pt != Type.recoveryType) {
3330                 /* We need to adjust the target. If the target is an
3331                  * intersection type, for example: SAM & I1 & I2 ...
3332                  * the target will be updated to SAM
3333                  */
3334                 currentTarget = targetChecker.visit(currentTarget, that);
3335                 if (!currentTarget.isIntersection()) {
3336                     if (explicitParamTypes != null) {
3337                         currentTarget = infer.instantiateFunctionalInterface(that,
3338                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3339                     }
3340                     currentTarget = types.removeWildcards(currentTarget);
3341                     lambdaType = types.findDescriptorType(currentTarget);
3342                 } else {
3343                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3344                     ListBuffer<Type> components = new ListBuffer<>();
3345                     for (Type bound : ict.getExplicitComponents()) {
3346                         if (explicitParamTypes != null) {
3347                             try {
3348                                 bound = infer.instantiateFunctionalInterface(that,
3349                                         bound, explicitParamTypes, resultInfo.checkContext);
3350                             } catch (FunctionDescriptorLookupError t) {
3351                                 // do nothing
3352                             }
3353                         }
3354                         if (bound.tsym != syms.objectType.tsym && (!bound.isInterface() || (bound.tsym.flags() & ANNOTATION) != 0)) {
3355                             // bound must be j.l.Object or an interface, but not an annotation
3356                             reportIntersectionError(that, "not.an.intf.component", bound);
3357                         }
3358                         bound = types.removeWildcards(bound);
3359                         components.add(bound);
3360                     }
3361                     currentTarget = types.makeIntersectionType(components.toList());
3362                     currentTarget.tsym.flags_field |= INTERFACE;
3363                     lambdaType = types.findDescriptorType(currentTarget);
3364                 }
3365 
3366             } else {
3367                 currentTarget = Type.recoveryType;
3368                 lambdaType = fallbackDescriptorType(that);
3369             }
3370             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3371                 //lambda expression target desc cannot be a generic method
3372                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3373                                                                     kindName(currentTarget.tsym),
3374                                                                     currentTarget.tsym);
3375                 resultInfo.checkContext.report(that, diags.fragment(msg));
3376                 currentTarget = types.createErrorType(pt());
3377             }
3378             return new TargetInfo(currentTarget, lambdaType);
3379         }
3380 
3381         private void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) {
3382              resultInfo.checkContext.report(pos,
3383                  diags.fragment(Fragments.BadIntersectionTargetForFunctionalExpr(diags.fragment(key, args))));
3384         }
3385 
3386         void preFlow(JCLambda tree) {
3387             attrRecover.doRecovery();
3388             new PostAttrAnalyzer() {
3389                 @Override
3390                 public void scan(JCTree tree) {
3391                     if (tree == null ||
3392                             (tree.type != null &&
3393                             tree.type == Type.stuckType)) {
3394                         //don't touch stuck expressions!
3395                         return;
3396                     }
3397                     super.scan(tree);
3398                 }
3399 
3400                 @Override
3401                 public void visitClassDef(JCClassDecl that) {
3402                     // or class declaration trees!
3403                 }
3404 
3405                 public void visitLambda(JCLambda that) {
3406                     // or lambda expressions!
3407                 }
3408             }.scan(tree.body);
3409         }
3410 
3411         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3412 
3413             @Override
3414             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3415                 return t.isIntersection() ?
3416                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3417             }
3418 
3419             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3420                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3421                 return ict;
3422             }
3423 
3424             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3425                 ListBuffer<Type> targs = new ListBuffer<>();
3426                 ListBuffer<Type> supertypes = new ListBuffer<>();
3427                 for (Type i : ict.interfaces_field) {
3428                     if (i.isParameterized()) {
3429                         targs.appendList(i.tsym.type.allparams());
3430                     }
3431                     supertypes.append(i.tsym.type);
3432                 }
3433                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3434                 notionalIntf.allparams_field = targs.toList();
3435                 notionalIntf.tsym.flags_field |= INTERFACE;
3436                 return notionalIntf.tsym;
3437             }
3438         };
3439 
3440         private Type fallbackDescriptorType(JCExpression tree) {
3441             switch (tree.getTag()) {
3442                 case LAMBDA:
3443                     JCLambda lambda = (JCLambda)tree;
3444                     List<Type> argtypes = List.nil();
3445                     for (JCVariableDecl param : lambda.params) {
3446                         argtypes = param.vartype != null && param.vartype.type != null ?
3447                                 argtypes.append(param.vartype.type) :
3448                                 argtypes.append(syms.errType);
3449                     }
3450                     return new MethodType(argtypes, Type.recoveryType,
3451                             List.of(syms.throwableType), syms.methodClass);
3452                 case REFERENCE:
3453                     return new MethodType(List.nil(), Type.recoveryType,
3454                             List.of(syms.throwableType), syms.methodClass);
3455                 default:
3456                     Assert.error("Cannot get here!");
3457             }
3458             return null;
3459         }
3460 
3461         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3462                 final InferenceContext inferenceContext, final Type... ts) {
3463             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3464         }
3465 
3466         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3467                 final InferenceContext inferenceContext, final List<Type> ts) {
3468             if (inferenceContext.free(ts)) {
3469                 inferenceContext.addFreeTypeListener(ts,
3470                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3471             } else {
3472                 for (Type t : ts) {
3473                     rs.checkAccessibleType(env, t);
3474                 }
3475             }
3476         }
3477 
3478         /**
3479          * Lambda/method reference have a special check context that ensures
3480          * that i.e. a lambda return type is compatible with the expected
3481          * type according to both the inherited context and the assignment
3482          * context.
3483          */
3484         class FunctionalReturnContext extends Check.NestedCheckContext {
3485 
3486             FunctionalReturnContext(CheckContext enclosingContext) {
3487                 super(enclosingContext);
3488             }
3489 
3490             @Override
3491             public boolean compatible(Type found, Type req, Warner warn) {
3492                 //return type must be compatible in both current context and assignment context
3493                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3494             }
3495 
3496             @Override
3497             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3498                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3499             }
3500         }
3501 
3502         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3503 
3504             JCExpression expr;
3505             boolean expStmtExpected;
3506 
3507             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3508                 super(enclosingContext);
3509                 this.expr = expr;
3510             }
3511 
3512             @Override
3513             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3514                 if (expStmtExpected) {
3515                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3516                 } else {
3517                     super.report(pos, details);
3518                 }
3519             }
3520 
3521             @Override
3522             public boolean compatible(Type found, Type req, Warner warn) {
3523                 //a void return is compatible with an expression statement lambda
3524                 if (req.hasTag(VOID)) {
3525                     expStmtExpected = true;
3526                     return TreeInfo.isExpressionStatement(expr);
3527                 } else {
3528                     return super.compatible(found, req, warn);
3529                 }
3530             }
3531         }
3532 
3533         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3534             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3535                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3536                     new FunctionalReturnContext(resultInfo.checkContext);
3537 
3538             return descriptor.getReturnType() == Type.recoveryType ?
3539                     recoveryInfo :
3540                     new ResultInfo(KindSelector.VAL,
3541                             descriptor.getReturnType(), funcContext);
3542         }
3543 
3544         /**
3545         * Lambda compatibility. Check that given return types, thrown types, parameter types
3546         * are compatible with the expected functional interface descriptor. This means that:
3547         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3548         * types must be compatible with the return type of the expected descriptor.
3549         */
3550         void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
3551             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3552 
3553             //return values have already been checked - but if lambda has no return
3554             //values, we must ensure that void/value compatibility is correct;
3555             //this amounts at checking that, if a lambda body can complete normally,
3556             //the descriptor's return type must be void
3557             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3558                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3559                 Fragment msg =
3560                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3561                 checkContext.report(tree,
3562                                     diags.fragment(msg));
3563             }
3564 
3565             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3566             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3567                 checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3568             }
3569         }
3570 
3571         /* This method returns an environment to be used to attribute a lambda
3572          * expression.
3573          *
3574          * The owner of this environment is a method symbol. If the current owner
3575          * is not a method (e.g. if the lambda occurs in a field initializer), then
3576          * a synthetic method symbol owner is created.
3577          */
3578         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3579             Env<AttrContext> lambdaEnv;
3580             Symbol owner = env.info.scope.owner;
3581             if (owner.kind == VAR && owner.owner.kind == TYP) {
3582                 // If the lambda is nested in a field initializer, we need to create a fake init method.
3583                 // Uniqueness of this symbol is not important (as e.g. annotations will be added on the
3584                 // init symbol's owner).
3585                 ClassSymbol enclClass = owner.enclClass();
3586                 Name initName = owner.isStatic() ? names.clinit : names.init;
3587                 MethodSymbol initSym = new MethodSymbol(BLOCK | (owner.isStatic() ? STATIC : 0) | SYNTHETIC | PRIVATE,
3588                         initName, initBlockType, enclClass);
3589                 initSym.params = List.nil();
3590                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(initSym)));
3591             } else {
3592                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3593             }
3594             lambdaEnv.info.yieldResult = null;
3595             lambdaEnv.info.isLambda = true;
3596             return lambdaEnv;
3597         }
3598 
3599     @Override
3600     public void visitReference(final JCMemberReference that) {
3601         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3602             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3603                 //method reference only allowed in assignment or method invocation/cast context
3604                 log.error(that.pos(), Errors.UnexpectedMref);
3605             }
3606             result = that.type = types.createErrorType(pt());
3607             return;
3608         }
3609         final Env<AttrContext> localEnv = env.dup(that);
3610         try {
3611             //attribute member reference qualifier - if this is a constructor
3612             //reference, the expected kind must be a type
3613             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3614 
3615             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3616                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3617                 if (!exprType.isErroneous() &&
3618                     exprType.isRaw() &&
3619                     that.typeargs != null) {
3620                     log.error(that.expr.pos(),
3621                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3622                                                  Fragments.MrefInferAndExplicitParams));
3623                     exprType = types.createErrorType(exprType);
3624                 }
3625             }
3626 
3627             if (exprType.isErroneous()) {
3628                 //if the qualifier expression contains problems,
3629                 //give up attribution of method reference
3630                 result = that.type = exprType;
3631                 return;
3632             }
3633 
3634             if (TreeInfo.isStaticSelector(that.expr, names)) {
3635                 //if the qualifier is a type, validate it; raw warning check is
3636                 //omitted as we don't know at this stage as to whether this is a
3637                 //raw selector (because of inference)
3638                 chk.validate(that.expr, env, false);
3639             } else {
3640                 Symbol lhsSym = TreeInfo.symbol(that.expr);
3641                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
3642             }
3643             //attrib type-arguments
3644             List<Type> typeargtypes = List.nil();
3645             if (that.typeargs != null) {
3646                 typeargtypes = attribTypes(that.typeargs, localEnv);
3647             }
3648 
3649             boolean isTargetSerializable =
3650                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3651                     rs.isSerializable(pt());
3652             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
3653             Type currentTarget = targetInfo.target;
3654             Type desc = targetInfo.descriptor;
3655 
3656             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
3657             List<Type> argtypes = desc.getParameterTypes();
3658             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
3659 
3660             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
3661                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
3662             }
3663 
3664             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
3665             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
3666             try {
3667                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
3668                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
3669                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
3670             } finally {
3671                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
3672             }
3673 
3674             Symbol refSym = refResult.fst;
3675             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
3676 
3677             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
3678              *  JDK-8075541
3679              */
3680             if (refSym.kind != MTH) {
3681                 boolean targetError;
3682                 switch (refSym.kind) {
3683                     case ABSENT_MTH:
3684                         targetError = false;
3685                         break;
3686                     case WRONG_MTH:
3687                     case WRONG_MTHS:
3688                     case AMBIGUOUS:
3689                     case HIDDEN:
3690                     case STATICERR:
3691                         targetError = true;
3692                         break;
3693                     default:
3694                         Assert.error("unexpected result kind " + refSym.kind);
3695                         targetError = false;
3696                 }
3697 
3698                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
3699                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
3700                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
3701 
3702                 JCDiagnostic diag = diags.create(log.currentSource(), that,
3703                         targetError ?
3704                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
3705                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
3706 
3707                 if (targetError && currentTarget == Type.recoveryType) {
3708                     //a target error doesn't make sense during recovery stage
3709                     //as we don't know what actual parameter types are
3710                     result = that.type = currentTarget;
3711                     return;
3712                 } else {
3713                     if (targetError) {
3714                         resultInfo.checkContext.report(that, diag);
3715                     } else {
3716                         log.report(diag);
3717                     }
3718                     result = that.type = types.createErrorType(currentTarget);
3719                     return;
3720                 }
3721             }
3722 
3723             that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
3724             that.kind = lookupHelper.referenceKind(that.sym);
3725             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
3726 
3727             if (desc.getReturnType() == Type.recoveryType) {
3728                 // stop here
3729                 result = that.type = currentTarget;
3730                 return;
3731             }
3732 
3733             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3734                 checkNewInnerClass(that.pos(), env, exprType, false);
3735             }
3736 
3737             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3738 
3739                 if (that.getMode() == ReferenceMode.INVOKE &&
3740                         TreeInfo.isStaticSelector(that.expr, names) &&
3741                         that.kind.isUnbound() &&
3742                         lookupHelper.site.isRaw()) {
3743                     chk.checkRaw(that.expr, localEnv);
3744                 }
3745 
3746                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
3747                         exprType.getTypeArguments().nonEmpty()) {
3748                     //static ref with class type-args
3749                     log.error(that.expr.pos(),
3750                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3751                                                  Fragments.StaticMrefWithTargs));
3752                     result = that.type = types.createErrorType(currentTarget);
3753                     return;
3754                 }
3755 
3756                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
3757                     // Check that super-qualified symbols are not abstract (JLS)
3758                     rs.checkNonAbstract(that.pos(), that.sym);
3759                 }
3760 
3761                 if (isTargetSerializable) {
3762                     chk.checkAccessFromSerializableElement(that, true);
3763                 }
3764             }
3765 
3766             ResultInfo checkInfo =
3767                     resultInfo.dup(newMethodTemplate(
3768                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
3769                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
3770                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3771 
3772             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
3773 
3774             if (that.kind.isUnbound() &&
3775                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
3776                 //re-generate inference constraints for unbound receiver
3777                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
3778                     //cannot happen as this has already been checked - we just need
3779                     //to regenerate the inference constraints, as that has been lost
3780                     //as a result of the call to inferenceContext.save()
3781                     Assert.error("Can't get here");
3782                 }
3783             }
3784 
3785             if (!refType.isErroneous()) {
3786                 refType = types.createMethodTypeWithReturn(refType,
3787                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
3788             }
3789 
3790             //go ahead with standard method reference compatibility check - note that param check
3791             //is a no-op (as this has been taken care during method applicability)
3792             boolean isSpeculativeRound =
3793                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3794 
3795             that.type = currentTarget; //avoids recovery at this stage
3796             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
3797             if (!isSpeculativeRound) {
3798                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
3799             }
3800             chk.checkRequiresIdentity(that, localEnv.info.lint);
3801             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3802         } catch (Types.FunctionDescriptorLookupError ex) {
3803             JCDiagnostic cause = ex.getDiagnostic();
3804             resultInfo.checkContext.report(that, cause);
3805             result = that.type = types.createErrorType(pt());
3806             return;
3807         }
3808     }
3809     //where
3810         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
3811             //if this is a constructor reference, the expected kind must be a type
3812             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
3813                                   KindSelector.VAL_TYP : KindSelector.TYP,
3814                                   Type.noType);
3815         }
3816 
3817 
3818     @SuppressWarnings("fallthrough")
3819     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
3820         InferenceContext inferenceContext = checkContext.inferenceContext();
3821         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
3822 
3823         Type resType;
3824         switch (tree.getMode()) {
3825             case NEW:
3826                 if (!tree.expr.type.isRaw()) {
3827                     resType = tree.expr.type;
3828                     break;
3829                 }
3830             default:
3831                 resType = refType.getReturnType();
3832         }
3833 
3834         Type incompatibleReturnType = resType;
3835 
3836         if (returnType.hasTag(VOID)) {
3837             incompatibleReturnType = null;
3838         }
3839 
3840         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
3841             if (resType.isErroneous() ||
3842                     new FunctionalReturnContext(checkContext).compatible(resType, returnType,
3843                             checkContext.checkWarner(tree, resType, returnType))) {
3844                 incompatibleReturnType = null;
3845             }
3846         }
3847 
3848         if (incompatibleReturnType != null) {
3849             Fragment msg =
3850                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
3851             checkContext.report(tree, diags.fragment(msg));
3852         } else {
3853             if (inferenceContext.free(refType)) {
3854                 // we need to wait for inference to finish and then replace inference vars in the referent type
3855                 inferenceContext.addFreeTypeListener(List.of(refType),
3856                         instantiatedContext -> {
3857                             tree.referentType = instantiatedContext.asInstType(refType);
3858                         });
3859             } else {
3860                 tree.referentType = refType;
3861             }
3862         }
3863 
3864         if (!speculativeAttr) {
3865             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
3866                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
3867             }
3868         }
3869     }
3870 
3871     boolean checkExConstraints(
3872             List<Type> thrownByFuncExpr,
3873             List<Type> thrownAtFuncType,
3874             InferenceContext inferenceContext) {
3875         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
3876          *  are not proper types
3877          */
3878         List<Type> nonProperList = thrownAtFuncType.stream()
3879                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
3880         List<Type> properList = thrownAtFuncType.diff(nonProperList);
3881 
3882         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
3883          *  in the throws clause of the invocation type of the method reference's compile-time
3884          *  declaration
3885          */
3886         List<Type> checkedList = thrownByFuncExpr.stream()
3887                 .filter(e -> chk.isChecked(e)).collect(List.collector());
3888 
3889         /** If n = 0 (the function type's throws clause consists only of proper types), then
3890          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
3891          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
3892          *  reduces to true
3893          */
3894         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
3895         for (Type checked : checkedList) {
3896             boolean isSubtype = false;
3897             for (Type proper : properList) {
3898                 if (types.isSubtype(checked, proper)) {
3899                     isSubtype = true;
3900                     break;
3901                 }
3902             }
3903             if (!isSubtype) {
3904                 uncaughtByProperTypes.add(checked);
3905             }
3906         }
3907 
3908         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
3909             return false;
3910         }
3911 
3912         /** If n > 0, the constraint reduces to a set of subtyping constraints:
3913          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
3914          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
3915          */
3916         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
3917         uncaughtByProperTypes.forEach(checkedEx -> {
3918             nonProperAsUndet.forEach(nonProper -> {
3919                 types.isSubtype(checkedEx, nonProper);
3920             });
3921         });
3922 
3923         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
3924          */
3925         nonProperAsUndet.stream()
3926                 .filter(t -> t.hasTag(UNDETVAR))
3927                 .forEach(t -> ((UndetVar)t).setThrow());
3928         return true;
3929     }
3930 
3931     /**
3932      * Set functional type info on the underlying AST. Note: as the target descriptor
3933      * might contain inference variables, we might need to register an hook in the
3934      * current inference context.
3935      */
3936     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
3937             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
3938         if (checkContext.inferenceContext().free(descriptorType)) {
3939             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
3940                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
3941                     inferenceContext.asInstType(primaryTarget), checkContext));
3942         } else {
3943             fExpr.owner = env.info.scope.owner;
3944             if (pt.hasTag(CLASS)) {
3945                 fExpr.target = primaryTarget;
3946             }
3947             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3948                     pt != Type.recoveryType) {
3949                 //check that functional interface class is well-formed
3950                 try {
3951                     /* Types.makeFunctionalInterfaceClass() may throw an exception
3952                      * when it's executed post-inference. See the listener code
3953                      * above.
3954                      */
3955                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
3956                             names.empty, fExpr.target, ABSTRACT);
3957                     if (csym != null) {
3958                         chk.checkImplementations(env.tree, csym, csym);
3959                         try {
3960                             //perform an additional functional interface check on the synthetic class,
3961                             //as there may be spurious errors for raw targets - because of existing issues
3962                             //with membership and inheritance (see JDK-8074570).
3963                             csym.flags_field |= INTERFACE;
3964                             types.findDescriptorType(csym.type);
3965                         } catch (FunctionDescriptorLookupError err) {
3966                             resultInfo.checkContext.report(fExpr,
3967                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
3968                         }
3969                     }
3970                 } catch (Types.FunctionDescriptorLookupError ex) {
3971                     JCDiagnostic cause = ex.getDiagnostic();
3972                     resultInfo.checkContext.report(env.tree, cause);
3973                 }
3974             }
3975         }
3976     }
3977 
3978     public void visitParens(JCParens tree) {
3979         Type owntype = attribTree(tree.expr, env, resultInfo);
3980         result = check(tree, owntype, pkind(), resultInfo);
3981         Symbol sym = TreeInfo.symbol(tree);
3982         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
3983             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
3984     }
3985 
3986     public void visitAssign(JCAssign tree) {
3987         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
3988         Type capturedType = capture(owntype);
3989         attribExpr(tree.rhs, env, owntype);
3990         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
3991     }
3992 
3993     public void visitAssignop(JCAssignOp tree) {
3994         // Attribute arguments.
3995         Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
3996         Type operand = attribExpr(tree.rhs, env);
3997         // Find operator.
3998         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
3999         if (operator != operators.noOpSymbol &&
4000                 !owntype.isErroneous() &&
4001                 !operand.isErroneous()) {
4002             chk.checkDivZero(tree.rhs.pos(), operator, operand);
4003             chk.checkCastable(tree.rhs.pos(),
4004                               operator.type.getReturnType(),
4005                               owntype);
4006             chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
4007         }
4008         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4009     }
4010 
4011     public void visitUnary(JCUnary tree) {
4012         // Attribute arguments.
4013         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
4014             ? attribTree(tree.arg, env, varAssignmentInfo)
4015             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
4016 
4017         // Find operator.
4018         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
4019         Type owntype = types.createErrorType(tree.type);
4020         if (operator != operators.noOpSymbol &&
4021                 !argtype.isErroneous()) {
4022             owntype = (tree.getTag().isIncOrDecUnaryOp())
4023                 ? tree.arg.type
4024                 : operator.type.getReturnType();
4025             int opc = operator.opcode;
4026 
4027             // If the argument is constant, fold it.
4028             if (argtype.constValue() != null) {
4029                 Type ctype = cfolder.fold1(opc, argtype);
4030                 if (ctype != null) {
4031                     owntype = cfolder.coerce(ctype, owntype);
4032                 }
4033             }
4034         }
4035         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4036         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4037     }
4038 
4039     public void visitBinary(JCBinary tree) {
4040         // Attribute arguments.
4041         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4042         // x && y
4043         // include x's bindings when true in y
4044 
4045         // x || y
4046         // include x's bindings when false in y
4047 
4048         MatchBindings lhsBindings = matchBindings;
4049         List<BindingSymbol> propagatedBindings;
4050         switch (tree.getTag()) {
4051             case AND:
4052                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4053                 break;
4054             case OR:
4055                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4056                 break;
4057             default:
4058                 propagatedBindings = List.nil();
4059                 break;
4060         }
4061         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4062         Type right;
4063         try {
4064             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4065         } finally {
4066             rhsEnv.info.scope.leave();
4067         }
4068 
4069         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4070 
4071         // Find operator.
4072         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4073         Type owntype = types.createErrorType(tree.type);
4074         if (operator != operators.noOpSymbol &&
4075                 !left.isErroneous() &&
4076                 !right.isErroneous()) {
4077             owntype = operator.type.getReturnType();
4078             int opc = operator.opcode;
4079             // If both arguments are constants, fold them.
4080             if (left.constValue() != null && right.constValue() != null) {
4081                 Type ctype = cfolder.fold2(opc, left, right);
4082                 if (ctype != null) {
4083                     owntype = cfolder.coerce(ctype, owntype);
4084                 }
4085             }
4086 
4087             // Check that argument types of a reference ==, != are
4088             // castable to each other, (JLS 15.21).  Note: unboxing
4089             // comparisons will not have an acmp* opc at this point.
4090             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4091                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4092                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4093                 }
4094             }
4095 
4096             chk.checkDivZero(tree.rhs.pos(), operator, right);
4097         }
4098         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4099     }
4100 
4101     public void visitTypeCast(final JCTypeCast tree) {
4102         Type clazztype = attribType(tree.clazz, env);
4103         chk.validate(tree.clazz, env, false);
4104         chk.checkRequiresIdentity(tree, env.info.lint);
4105         //a fresh environment is required for 292 inference to work properly ---
4106         //see Infer.instantiatePolymorphicSignatureInstance()
4107         Env<AttrContext> localEnv = env.dup(tree);
4108         //should we propagate the target type?
4109         final ResultInfo castInfo;
4110         JCExpression expr = TreeInfo.skipParens(tree.expr);
4111         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4112         if (isPoly) {
4113             //expression is a poly - we need to propagate target type info
4114             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4115                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4116                 @Override
4117                 public boolean compatible(Type found, Type req, Warner warn) {
4118                     return types.isCastable(found, req, warn);
4119                 }
4120             });
4121         } else {
4122             //standalone cast - target-type info is not propagated
4123             castInfo = unknownExprInfo;
4124         }
4125         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4126         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4127         if (exprtype.constValue() != null)
4128             owntype = cfolder.coerce(exprtype, owntype);
4129         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4130         if (!isPoly)
4131             chk.checkRedundantCast(localEnv, tree);
4132     }
4133 
4134     public void visitTypeTest(JCInstanceOf tree) {
4135         Type exprtype = attribExpr(tree.expr, env);
4136         if (exprtype.isPrimitive()) {
4137             preview.checkSourceLevel(tree.expr.pos(), Feature.PRIMITIVE_PATTERNS);
4138         } else {
4139             exprtype = chk.checkNullOrRefType(
4140                     tree.expr.pos(), exprtype);
4141         }
4142         Type clazztype;
4143         JCTree typeTree;
4144         if (tree.pattern.getTag() == BINDINGPATTERN ||
4145             tree.pattern.getTag() == RECORDPATTERN) {
4146             attribExpr(tree.pattern, env, exprtype);
4147             clazztype = tree.pattern.type;
4148             if (types.isSubtype(exprtype, clazztype) &&
4149                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4150                 tree.pattern.getTag() != RECORDPATTERN) {
4151                 if (!allowUnconditionalPatternsInstanceOf) {
4152                     log.error(tree.pos(), Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.error(this.sourceName));
4153                 }
4154             }
4155             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4156         } else {
4157             clazztype = attribType(tree.pattern, env);
4158             typeTree = tree.pattern;
4159             chk.validate(typeTree, env, false);
4160         }
4161         if (clazztype.isPrimitive()) {
4162             preview.checkSourceLevel(tree.pattern.pos(), Feature.PRIMITIVE_PATTERNS);
4163         } else {
4164             if (!clazztype.hasTag(TYPEVAR)) {
4165                 clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4166             }
4167             if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4168                 boolean valid = false;
4169                 if (allowReifiableTypesInInstanceof) {
4170                     valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4171                 } else {
4172                     log.error(tree.pos(), Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4173                     allowReifiableTypesInInstanceof = true;
4174                 }
4175                 if (!valid) {
4176                     clazztype = types.createErrorType(clazztype);
4177                 }
4178             }
4179         }
4180         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4181         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4182     }
4183 
4184     private boolean checkCastablePattern(DiagnosticPosition pos,
4185                                          Type exprType,
4186                                          Type pattType) {
4187         Warner warner = new Warner();
4188         // if any type is erroneous, the problem is reported elsewhere
4189         if (exprType.isErroneous() || pattType.isErroneous()) {
4190             return false;
4191         }
4192         if (!types.isCastable(exprType, pattType, warner)) {
4193             chk.basicHandler.report(pos,
4194                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4195             return false;
4196         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4197                 (!exprType.isPrimitive() || !pattType.isPrimitive() || !types.isSameType(exprType, pattType))) {
4198             preview.checkSourceLevel(pos, Feature.PRIMITIVE_PATTERNS);
4199             return true;
4200         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4201             log.error(pos,
4202                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4203             return false;
4204         } else {
4205             return true;
4206         }
4207     }
4208 
4209     @Override
4210     public void visitAnyPattern(JCAnyPattern tree) {
4211         result = tree.type = resultInfo.pt;
4212     }
4213 
4214     public void visitBindingPattern(JCBindingPattern tree) {
4215         Type type;
4216         if (tree.var.vartype != null) {
4217             type = attribType(tree.var.vartype, env);
4218         } else {
4219             type = resultInfo.pt;
4220         }
4221         tree.type = tree.var.type = type;
4222         BindingSymbol v = new BindingSymbol(tree.var.mods.flags, tree.var.name, type, env.info.scope.owner);
4223         v.pos = tree.pos;
4224         tree.var.sym = v;
4225         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4226             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4227         }
4228         chk.validate(tree.var.vartype, env, true);
4229         if (tree.var.isImplicitlyTyped()) {
4230             setSyntheticVariableType(tree.var, type == Type.noType ? syms.errType
4231                                                                    : type);
4232         }
4233         annotate.annotateLater(tree.var.mods.annotations, env, v);
4234         if (!tree.var.isImplicitlyTyped()) {
4235             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v);
4236         }
4237         annotate.flush();
4238         result = tree.type;
4239         if (v.isUnnamedVariable()) {
4240             matchBindings = MatchBindingsComputer.EMPTY;
4241         } else {
4242             matchBindings = new MatchBindings(List.of(v), List.nil());
4243         }
4244         chk.checkRequiresIdentity(tree, env.info.lint);
4245     }
4246 
4247     @Override
4248     public void visitRecordPattern(JCRecordPattern tree) {
4249         Type site;
4250 
4251         if (tree.deconstructor == null) {
4252             log.error(tree.pos(), Errors.DeconstructionPatternVarNotAllowed);
4253             tree.record = syms.errSymbol;
4254             site = tree.type = types.createErrorType(tree.record.type);
4255         } else {
4256             Type type = attribType(tree.deconstructor, env);
4257             if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4258                 Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4259                 if (inferred == null) {
4260                     log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4261                 } else {
4262                     type = inferred;
4263                 }
4264             }
4265             tree.type = tree.deconstructor.type = type;
4266             site = types.capture(tree.type);
4267         }
4268 
4269         List<Type> expectedRecordTypes;
4270         if (site.tsym.kind == Kind.TYP && ((ClassSymbol) site.tsym).isRecord()) {
4271             ClassSymbol record = (ClassSymbol) site.tsym;
4272             expectedRecordTypes = record.getRecordComponents()
4273                                         .stream()
4274                                         .map(rc -> types.memberType(site, rc))
4275                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4276                                         .collect(List.collector());
4277             tree.record = record;
4278         } else {
4279             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4280             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4281                                 .limit(tree.nested.size())
4282                                 .collect(List.collector());
4283             tree.record = syms.errSymbol;
4284         }
4285         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4286         List<Type> recordTypes = expectedRecordTypes;
4287         List<JCPattern> nestedPatterns = tree.nested;
4288         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4289         try {
4290             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4291                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4292                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4293                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4294                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4295                 nestedPatterns = nestedPatterns.tail;
4296                 recordTypes = recordTypes.tail;
4297             }
4298             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4299                 while (nestedPatterns.nonEmpty()) {
4300                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4301                     nestedPatterns = nestedPatterns.tail;
4302                 }
4303                 List<Type> nestedTypes =
4304                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4305                 log.error(tree.pos(),
4306                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4307                                                                  nestedTypes));
4308             }
4309         } finally {
4310             localEnv.info.scope.leave();
4311         }
4312         chk.validate(tree.deconstructor, env, true);
4313         result = tree.type;
4314         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4315     }
4316 
4317     public void visitIndexed(JCArrayAccess tree) {
4318         Type owntype = types.createErrorType(tree.type);
4319         Type atype = attribExpr(tree.indexed, env);
4320         attribExpr(tree.index, env, syms.intType);
4321         if (types.isArray(atype))
4322             owntype = types.elemtype(atype);
4323         else if (!atype.hasTag(ERROR))
4324             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4325         if (!pkind().contains(KindSelector.VAL))
4326             owntype = capture(owntype);
4327         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4328     }
4329 
4330     public void visitIdent(JCIdent tree) {
4331         Symbol sym;
4332 
4333         // Find symbol
4334         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4335             // If we are looking for a method, the prototype `pt' will be a
4336             // method type with the type of the call's arguments as parameters.
4337             env.info.pendingResolutionPhase = null;
4338             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4339         } else if (tree.sym != null && tree.sym.kind != VAR) {
4340             sym = tree.sym;
4341         } else {
4342             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4343         }
4344         tree.sym = sym;
4345 
4346         // Also find the environment current for the class where
4347         // sym is defined (`symEnv').
4348         Env<AttrContext> symEnv = env;
4349         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4350             sym.kind.matches(KindSelector.VAL_MTH) &&
4351             sym.owner.kind == TYP &&
4352             tree.name != names._this && tree.name != names._super) {
4353 
4354             // Find environment in which identifier is defined.
4355             while (symEnv.outer != null &&
4356                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4357                 symEnv = symEnv.outer;
4358             }
4359         }
4360 
4361         // If symbol is a variable, ...
4362         if (sym.kind == VAR) {
4363             VarSymbol v = (VarSymbol)sym;
4364 
4365             // ..., evaluate its initializer, if it has one, and check for
4366             // illegal forward reference.
4367             checkInit(tree, env, v, false);
4368 
4369             // If we are expecting a variable (as opposed to a value), check
4370             // that the variable is assignable in the current environment.
4371             if (KindSelector.ASG.subset(pkind()))
4372                 checkAssignable(tree.pos(), v, null, env);
4373         }
4374 
4375         Env<AttrContext> env1 = env;
4376         if (sym.kind != ERR && sym.kind != TYP &&
4377             sym.owner != null && sym.owner != env1.enclClass.sym) {
4378             // If the found symbol is inaccessible, then it is
4379             // accessed through an enclosing instance.  Locate this
4380             // enclosing instance:
4381             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4382                 env1 = env1.outer;
4383         }
4384 
4385         if (env.info.isSerializable) {
4386             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4387         }
4388 
4389         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4390     }
4391 
4392     public void visitSelect(JCFieldAccess tree) {
4393         // Determine the expected kind of the qualifier expression.
4394         KindSelector skind = KindSelector.NIL;
4395         if (tree.name == names._this || tree.name == names._super ||
4396                 tree.name == names._class)
4397         {
4398             skind = KindSelector.TYP;
4399         } else {
4400             if (pkind().contains(KindSelector.PCK))
4401                 skind = KindSelector.of(skind, KindSelector.PCK);
4402             if (pkind().contains(KindSelector.TYP))
4403                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4404             if (pkind().contains(KindSelector.VAL_MTH))
4405                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4406         }
4407 
4408         // Attribute the qualifier expression, and determine its symbol (if any).
4409         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
4410         if (!pkind().contains(KindSelector.TYP_PCK))
4411             site = capture(site); // Capture field access
4412 
4413         // don't allow T.class T[].class, etc
4414         if (skind == KindSelector.TYP) {
4415             Type elt = site;
4416             while (elt.hasTag(ARRAY))
4417                 elt = ((ArrayType)elt).elemtype;
4418             if (elt.hasTag(TYPEVAR)) {
4419                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4420                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4421                 tree.sym = tree.type.tsym;
4422                 return ;
4423             }
4424         }
4425 
4426         // If qualifier symbol is a type or `super', assert `selectSuper'
4427         // for the selection. This is relevant for determining whether
4428         // protected symbols are accessible.
4429         Symbol sitesym = TreeInfo.symbol(tree.selected);
4430         boolean selectSuperPrev = env.info.selectSuper;
4431         env.info.selectSuper =
4432             sitesym != null &&
4433             sitesym.name == names._super;
4434 
4435         // Determine the symbol represented by the selection.
4436         env.info.pendingResolutionPhase = null;
4437         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
4438         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4439             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4440             sym = syms.errSymbol;
4441         }
4442         if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
4443             site = capture(site);
4444             sym = selectSym(tree, sitesym, site, env, resultInfo);
4445         }
4446         boolean varArgs = env.info.lastResolveVarargs();
4447         tree.sym = sym;
4448 
4449         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4450             site = types.skipTypeVars(site, true);
4451         }
4452 
4453         // If that symbol is a variable, ...
4454         if (sym.kind == VAR) {
4455             VarSymbol v = (VarSymbol)sym;
4456 
4457             // ..., evaluate its initializer, if it has one, and check for
4458             // illegal forward reference.
4459             checkInit(tree, env, v, true);
4460 
4461             // If we are expecting a variable (as opposed to a value), check
4462             // that the variable is assignable in the current environment.
4463             if (KindSelector.ASG.subset(pkind()))
4464                 checkAssignable(tree.pos(), v, tree.selected, env);
4465         }
4466 
4467         if (sitesym != null &&
4468                 sitesym.kind == VAR &&
4469                 ((VarSymbol)sitesym).isResourceVariable() &&
4470                 sym.kind == MTH &&
4471                 sym.name.equals(names.close) &&
4472                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true)) {
4473             log.warning(tree, LintWarnings.TryExplicitCloseCall);
4474         }
4475 
4476         // Disallow selecting a type from an expression
4477         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4478             tree.type = check(tree.selected, pt(),
4479                               sitesym == null ?
4480                                       KindSelector.VAL : sitesym.kind.toSelector(),
4481                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4482         }
4483 
4484         if (isType(sitesym)) {
4485             if (sym.name != names._this && sym.name != names._super) {
4486                 // Check if type-qualified fields or methods are static (JLS)
4487                 if ((sym.flags() & STATIC) == 0 &&
4488                     sym.name != names._super &&
4489                     (sym.kind == VAR || sym.kind == MTH)) {
4490                     rs.accessBase(rs.new StaticError(sym),
4491                               tree.pos(), site, sym.name, true);
4492                 }
4493             }
4494         } else if (sym.kind != ERR &&
4495                    (sym.flags() & STATIC) != 0 &&
4496                    sym.name != names._class) {
4497             // If the qualified item is not a type and the selected item is static, report
4498             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4499             if (!sym.owner.isAnonymous()) {
4500                 log.warning(tree, LintWarnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4501             } else {
4502                 log.warning(tree, LintWarnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4503             }
4504         }
4505 
4506         // If we are selecting an instance member via a `super', ...
4507         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4508 
4509             // Check that super-qualified symbols are not abstract (JLS)
4510             rs.checkNonAbstract(tree.pos(), sym);
4511 
4512             if (site.isRaw()) {
4513                 // Determine argument types for site.
4514                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
4515                 if (site1 != null) site = site1;
4516             }
4517         }
4518 
4519         if (env.info.isSerializable) {
4520             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4521         }
4522 
4523         env.info.selectSuper = selectSuperPrev;
4524         result = checkId(tree, site, sym, env, resultInfo);
4525     }
4526     //where
4527         /** Determine symbol referenced by a Select expression,
4528          *
4529          *  @param tree   The select tree.
4530          *  @param site   The type of the selected expression,
4531          *  @param env    The current environment.
4532          *  @param resultInfo The current result.
4533          */
4534         private Symbol selectSym(JCFieldAccess tree,
4535                                  Symbol location,
4536                                  Type site,
4537                                  Env<AttrContext> env,
4538                                  ResultInfo resultInfo) {
4539             DiagnosticPosition pos = tree.pos();
4540             Name name = tree.name;
4541             switch (site.getTag()) {
4542             case PACKAGE:
4543                 return rs.accessBase(
4544                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4545                     pos, location, site, name, true);
4546             case ARRAY:
4547             case CLASS:
4548                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4549                     return rs.resolveQualifiedMethod(
4550                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4551                 } else if (name == names._this || name == names._super) {
4552                     return rs.resolveSelf(pos, env, site.tsym, tree);
4553                 } else if (name == names._class) {
4554                     // In this case, we have already made sure in
4555                     // visitSelect that qualifier expression is a type.
4556                     return syms.getClassField(site, types);
4557                 } else {
4558                     // We are seeing a plain identifier as selector.
4559                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
4560                         sym = rs.accessBase(sym, pos, location, site, name, true);
4561                     return sym;
4562                 }
4563             case WILDCARD:
4564                 throw new AssertionError(tree);
4565             case TYPEVAR:
4566                 // Normally, site.getUpperBound() shouldn't be null.
4567                 // It should only happen during memberEnter/attribBase
4568                 // when determining the supertype which *must* be
4569                 // done before attributing the type variables.  In
4570                 // other words, we are seeing this illegal program:
4571                 // class B<T> extends A<T.foo> {}
4572                 Symbol sym = (site.getUpperBound() != null)
4573                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
4574                     : null;
4575                 if (sym == null) {
4576                     log.error(pos, Errors.TypeVarCantBeDeref);
4577                     return syms.errSymbol;
4578                 } else {
4579                     // JLS 4.9 specifies the members are derived by inheritance.
4580                     // We skip inducing a whole class by filtering members that
4581                     // can never be inherited:
4582                     Symbol sym2;
4583                     if (sym.isPrivate()) {
4584                         // Private members
4585                         sym2 = rs.new AccessError(env, site, sym);
4586                     } else if (sym.owner.isInterface() && sym.kind == MTH && (sym.flags() & STATIC) != 0) {
4587                         // Interface static methods
4588                         sym2 = rs.new SymbolNotFoundError(ABSENT_MTH);
4589                     } else {
4590                         sym2 = sym;
4591                     }
4592                     rs.accessBase(sym2, pos, location, site, name, true);
4593                     return sym;
4594                 }
4595             case ERROR:
4596                 // preserve identifier names through errors
4597                 return types.createErrorType(name, site.tsym, site).tsym;
4598             default:
4599                 // The qualifier expression is of a primitive type -- only
4600                 // .class is allowed for these.
4601                 if (name == names._class) {
4602                     // In this case, we have already made sure in Select that
4603                     // qualifier expression is a type.
4604                     return syms.getClassField(site, types);
4605                 } else {
4606                     log.error(pos, Errors.CantDeref(site));
4607                     return syms.errSymbol;
4608                 }
4609             }
4610         }
4611 
4612         /** Determine type of identifier or select expression and check that
4613          *  (1) the referenced symbol is not deprecated
4614          *  (2) the symbol's type is safe (@see checkSafe)
4615          *  (3) if symbol is a variable, check that its type and kind are
4616          *      compatible with the prototype and protokind.
4617          *  (4) if symbol is an instance field of a raw type,
4618          *      which is being assigned to, issue an unchecked warning if its
4619          *      type changes under erasure.
4620          *  (5) if symbol is an instance method of a raw type, issue an
4621          *      unchecked warning if its argument types change under erasure.
4622          *  If checks succeed:
4623          *    If symbol is a constant, return its constant type
4624          *    else if symbol is a method, return its result type
4625          *    otherwise return its type.
4626          *  Otherwise return errType.
4627          *
4628          *  @param tree       The syntax tree representing the identifier
4629          *  @param site       If this is a select, the type of the selected
4630          *                    expression, otherwise the type of the current class.
4631          *  @param sym        The symbol representing the identifier.
4632          *  @param env        The current environment.
4633          *  @param resultInfo    The expected result
4634          */
4635         Type checkId(JCTree tree,
4636                      Type site,
4637                      Symbol sym,
4638                      Env<AttrContext> env,
4639                      ResultInfo resultInfo) {
4640             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
4641                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
4642                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4643         }
4644 
4645         Type checkMethodIdInternal(JCTree tree,
4646                      Type site,
4647                      Symbol sym,
4648                      Env<AttrContext> env,
4649                      ResultInfo resultInfo) {
4650             if (resultInfo.pkind.contains(KindSelector.POLY)) {
4651                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
4652             } else {
4653                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4654             }
4655         }
4656 
4657         Type checkIdInternal(JCTree tree,
4658                      Type site,
4659                      Symbol sym,
4660                      Type pt,
4661                      Env<AttrContext> env,
4662                      ResultInfo resultInfo) {
4663             Type owntype; // The computed type of this identifier occurrence.
4664             switch (sym.kind) {
4665             case TYP:
4666                 // For types, the computed type equals the symbol's type,
4667                 // except for two situations:
4668                 owntype = sym.type;
4669                 if (owntype.hasTag(CLASS)) {
4670                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
4671                     Type ownOuter = owntype.getEnclosingType();
4672 
4673                     // (a) If the symbol's type is parameterized, erase it
4674                     // because no type parameters were given.
4675                     // We recover generic outer type later in visitTypeApply.
4676                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
4677                         owntype = types.erasure(owntype);
4678                     }
4679 
4680                     // (b) If the symbol's type is an inner class, then
4681                     // we have to interpret its outer type as a superclass
4682                     // of the site type. Example:
4683                     //
4684                     // class Tree<A> { class Visitor { ... } }
4685                     // class PointTree extends Tree<Point> { ... }
4686                     // ...PointTree.Visitor...
4687                     //
4688                     // Then the type of the last expression above is
4689                     // Tree<Point>.Visitor.
4690                     else if ((ownOuter.hasTag(CLASS) || ownOuter.hasTag(TYPEVAR)) && site != ownOuter) {
4691                         Type normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
4692                         if (normOuter == null) // perhaps from an import
4693                             normOuter = types.erasure(ownOuter);
4694                         if (normOuter != ownOuter)
4695                             owntype = new ClassType(
4696                                 normOuter, List.nil(), owntype.tsym,
4697                                 owntype.getMetadata());
4698                     }
4699                 }
4700                 break;
4701             case VAR:
4702                 VarSymbol v = (VarSymbol)sym;
4703 
4704                 if (env.info.enclVar != null
4705                         && v.type.hasTag(NONE)) {
4706                     //self reference to implicitly typed variable declaration
4707                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
4708                     return tree.type = v.type = types.createErrorType(v.type);
4709                 }
4710 
4711                 // Test (4): if symbol is an instance field of a raw type,
4712                 // which is being assigned to, issue an unchecked warning if
4713                 // its type changes under erasure.
4714                 if (KindSelector.ASG.subset(pkind()) &&
4715                     v.owner.kind == TYP &&
4716                     (v.flags() & STATIC) == 0 &&
4717                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4718                     Type s = types.asOuterSuper(site, v.owner);
4719                     if (s != null &&
4720                         s.isRaw() &&
4721                         !types.isSameType(v.type, v.erasure(types))) {
4722                         chk.warnUnchecked(tree.pos(), LintWarnings.UncheckedAssignToVar(v, s));
4723                     }
4724                 }
4725                 // The computed type of a variable is the type of the
4726                 // variable symbol, taken as a member of the site type.
4727                 owntype = (sym.owner.kind == TYP &&
4728                            sym.name != names._this && sym.name != names._super)
4729                     ? types.memberType(site, sym)
4730                     : sym.type;
4731 
4732                 // If the variable is a constant, record constant value in
4733                 // computed type.
4734                 if (v.getConstValue() != null && isStaticReference(tree))
4735                     owntype = owntype.constType(v.getConstValue());
4736 
4737                 if (resultInfo.pkind == KindSelector.VAL) {
4738                     owntype = capture(owntype); // capture "names as expressions"
4739                 }
4740                 break;
4741             case MTH: {
4742                 owntype = checkMethod(site, sym,
4743                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
4744                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
4745                         resultInfo.pt.getTypeArguments());
4746                 chk.checkRestricted(tree.pos(), sym);
4747                 break;
4748             }
4749             case PCK: case ERR:
4750                 owntype = sym.type;
4751                 break;
4752             default:
4753                 throw new AssertionError("unexpected kind: " + sym.kind +
4754                                          " in tree " + tree);
4755             }
4756 
4757             // Emit a `deprecation' warning if symbol is deprecated.
4758             // (for constructors (but not for constructor references), the error
4759             // was given when the constructor was resolved)
4760 
4761             if (sym.name != names.init || tree.hasTag(REFERENCE)) {
4762                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
4763                 chk.checkSunAPI(tree.pos(), sym);
4764                 chk.checkProfile(tree.pos(), sym);
4765                 chk.checkPreview(tree.pos(), env.info.scope.owner, site, sym);
4766             }
4767 
4768             if (pt.isErroneous()) {
4769                 owntype = types.createErrorType(owntype);
4770             }
4771 
4772             // If symbol is a variable, check that its type and
4773             // kind are compatible with the prototype and protokind.
4774             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
4775         }
4776 
4777         /** Check that variable is initialized and evaluate the variable's
4778          *  initializer, if not yet done. Also check that variable is not
4779          *  referenced before it is defined.
4780          *  @param tree    The tree making up the variable reference.
4781          *  @param env     The current environment.
4782          *  @param v       The variable's symbol.
4783          */
4784         private void checkInit(JCTree tree,
4785                                Env<AttrContext> env,
4786                                VarSymbol v,
4787                                boolean onlyWarning) {
4788             // A forward reference is diagnosed if the declaration position
4789             // of the variable is greater than the current tree position
4790             // and the tree and variable definition occur in the same class
4791             // definition.  Note that writes don't count as references.
4792             // This check applies only to class and instance
4793             // variables.  Local variables follow different scope rules,
4794             // and are subject to definite assignment checking.
4795             Env<AttrContext> initEnv = enclosingInitEnv(env);
4796             if (initEnv != null &&
4797                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
4798                 v.owner.kind == TYP &&
4799                 v.owner == env.info.scope.owner.enclClass() &&
4800                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
4801                 (!env.tree.hasTag(ASSIGN) ||
4802                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
4803                 if (!onlyWarning || isStaticEnumField(v)) {
4804                     Error errkey = (initEnv.info.enclVar == v) ?
4805                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
4806                     log.error(tree.pos(), errkey);
4807                 } else if (useBeforeDeclarationWarning) {
4808                     Warning warnkey = (initEnv.info.enclVar == v) ?
4809                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
4810                     log.warning(tree.pos(), warnkey);
4811                 }
4812             }
4813 
4814             v.getConstValue(); // ensure initializer is evaluated
4815 
4816             checkEnumInitializer(tree, env, v);
4817         }
4818 
4819         /**
4820          * Returns the enclosing init environment associated with this env (if any). An init env
4821          * can be either a field declaration env or a static/instance initializer env.
4822          */
4823         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
4824             while (true) {
4825                 switch (env.tree.getTag()) {
4826                     case VARDEF:
4827                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
4828                         if (vdecl.sym.owner.kind == TYP) {
4829                             //field
4830                             return env;
4831                         }
4832                         break;
4833                     case BLOCK:
4834                         if (env.next.tree.hasTag(CLASSDEF)) {
4835                             //instance/static initializer
4836                             return env;
4837                         }
4838                         break;
4839                     case METHODDEF:
4840                     case CLASSDEF:
4841                     case TOPLEVEL:
4842                         return null;
4843                 }
4844                 Assert.checkNonNull(env.next);
4845                 env = env.next;
4846             }
4847         }
4848 
4849         /**
4850          * Check for illegal references to static members of enum.  In
4851          * an enum type, constructors and initializers may not
4852          * reference its static members unless they are constant.
4853          *
4854          * @param tree    The tree making up the variable reference.
4855          * @param env     The current environment.
4856          * @param v       The variable's symbol.
4857          * @jls 8.9 Enum Types
4858          */
4859         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
4860             // JLS:
4861             //
4862             // "It is a compile-time error to reference a static field
4863             // of an enum type that is not a compile-time constant
4864             // (15.28) from constructors, instance initializer blocks,
4865             // or instance variable initializer expressions of that
4866             // type. It is a compile-time error for the constructors,
4867             // instance initializer blocks, or instance variable
4868             // initializer expressions of an enum constant e to refer
4869             // to itself or to an enum constant of the same type that
4870             // is declared to the right of e."
4871             if (isStaticEnumField(v)) {
4872                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
4873 
4874                 if (enclClass == null || enclClass.owner == null)
4875                     return;
4876 
4877                 // See if the enclosing class is the enum (or a
4878                 // subclass thereof) declaring v.  If not, this
4879                 // reference is OK.
4880                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
4881                     return;
4882 
4883                 // If the reference isn't from an initializer, then
4884                 // the reference is OK.
4885                 if (!Resolve.isInitializer(env))
4886                     return;
4887 
4888                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
4889             }
4890         }
4891 
4892         /** Is the given symbol a static, non-constant field of an Enum?
4893          *  Note: enum literals should not be regarded as such
4894          */
4895         private boolean isStaticEnumField(VarSymbol v) {
4896             return Flags.isEnum(v.owner) &&
4897                    Flags.isStatic(v) &&
4898                    !Flags.isConstant(v) &&
4899                    v.name != names._class;
4900         }
4901 
4902     /**
4903      * Check that method arguments conform to its instantiation.
4904      **/
4905     public Type checkMethod(Type site,
4906                             final Symbol sym,
4907                             ResultInfo resultInfo,
4908                             Env<AttrContext> env,
4909                             final List<JCExpression> argtrees,
4910                             List<Type> argtypes,
4911                             List<Type> typeargtypes) {
4912         // Test (5): if symbol is an instance method of a raw type, issue
4913         // an unchecked warning if its argument types change under erasure.
4914         if ((sym.flags() & STATIC) == 0 &&
4915             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4916             Type s = types.asOuterSuper(site, sym.owner);
4917             if (s != null && s.isRaw() &&
4918                 !types.isSameTypes(sym.type.getParameterTypes(),
4919                                    sym.erasure(types).getParameterTypes())) {
4920                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedCallMbrOfRawType(sym, s));
4921             }
4922         }
4923 
4924         if (env.info.defaultSuperCallSite != null) {
4925             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
4926                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
4927                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
4928                 List<MethodSymbol> icand_sup =
4929                         types.interfaceCandidates(sup, (MethodSymbol)sym);
4930                 if (icand_sup.nonEmpty() &&
4931                         icand_sup.head != sym &&
4932                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
4933                     log.error(env.tree.pos(),
4934                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
4935                     break;
4936                 }
4937             }
4938             env.info.defaultSuperCallSite = null;
4939         }
4940 
4941         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
4942             JCMethodInvocation app = (JCMethodInvocation)env.tree;
4943             if (app.meth.hasTag(SELECT) &&
4944                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
4945                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
4946             }
4947         }
4948 
4949         // Compute the identifier's instantiated type.
4950         // For methods, we need to compute the instance type by
4951         // Resolve.instantiate from the symbol's type as well as
4952         // any type arguments and value arguments.
4953         Warner noteWarner = new Warner();
4954         try {
4955             Type owntype = rs.checkMethod(
4956                     env,
4957                     site,
4958                     sym,
4959                     resultInfo,
4960                     argtypes,
4961                     typeargtypes,
4962                     noteWarner);
4963 
4964             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
4965                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
4966 
4967             argtypes = argtypes.map(checkDeferredMap);
4968 
4969             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
4970                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedMethInvocationApplied(kindName(sym),
4971                         sym.name,
4972                         rs.methodArguments(sym.type.getParameterTypes()),
4973                         rs.methodArguments(argtypes.map(checkDeferredMap)),
4974                         kindName(sym.location()),
4975                         sym.location()));
4976                 if (resultInfo.pt != Infer.anyPoly ||
4977                         !owntype.hasTag(METHOD) ||
4978                         !owntype.isPartial()) {
4979                     //if this is not a partially inferred method type, erase return type. Otherwise,
4980                     //erasure is carried out in PartiallyInferredMethodType.check().
4981                     owntype = new MethodType(owntype.getParameterTypes(),
4982                             types.erasure(owntype.getReturnType()),
4983                             types.erasure(owntype.getThrownTypes()),
4984                             syms.methodClass);
4985                 }
4986             }
4987 
4988             PolyKind pkind = (sym.type.hasTag(FORALL) &&
4989                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
4990                  PolyKind.POLY : PolyKind.STANDALONE;
4991             TreeInfo.setPolyKind(env.tree, pkind);
4992 
4993             return (resultInfo.pt == Infer.anyPoly) ?
4994                     owntype :
4995                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
4996                             resultInfo.checkContext.inferenceContext());
4997         } catch (Infer.InferenceException ex) {
4998             //invalid target type - propagate exception outwards or report error
4999             //depending on the current check context
5000             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
5001             return types.createErrorType(site);
5002         } catch (Resolve.InapplicableMethodException ex) {
5003             final JCDiagnostic diag = ex.getDiagnostic();
5004             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
5005                 @Override
5006                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
5007                     return new Pair<>(sym, diag);
5008                 }
5009             };
5010             List<Type> argtypes2 = argtypes.map(
5011                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
5012             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
5013                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
5014             log.report(errDiag);
5015             return types.createErrorType(site);
5016         }
5017     }
5018 
5019     public void visitLiteral(JCLiteral tree) {
5020         result = check(tree, litType(tree.typetag).constType(tree.value),
5021                 KindSelector.VAL, resultInfo);
5022     }
5023     //where
5024     /** Return the type of a literal with given type tag.
5025      */
5026     Type litType(TypeTag tag) {
5027         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
5028     }
5029 
5030     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5031         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5032     }
5033 
5034     public void visitTypeArray(JCArrayTypeTree tree) {
5035         Type etype = attribType(tree.elemtype, env);
5036         Type type = new ArrayType(etype, syms.arrayClass);
5037         result = check(tree, type, KindSelector.TYP, resultInfo);
5038     }
5039 
5040     /** Visitor method for parameterized types.
5041      *  Bound checking is left until later, since types are attributed
5042      *  before supertype structure is completely known
5043      */
5044     public void visitTypeApply(JCTypeApply tree) {
5045         Type owntype = types.createErrorType(tree.type);
5046 
5047         // Attribute functor part of application and make sure it's a class.
5048         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5049 
5050         // Attribute type parameters
5051         List<Type> actuals = attribTypes(tree.arguments, env);
5052 
5053         if (clazztype.hasTag(CLASS)) {
5054             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5055             if (actuals.isEmpty()) //diamond
5056                 actuals = formals;
5057 
5058             if (actuals.length() == formals.length()) {
5059                 List<Type> a = actuals;
5060                 List<Type> f = formals;
5061                 while (a.nonEmpty()) {
5062                     a.head = a.head.withTypeVar(f.head);
5063                     a = a.tail;
5064                     f = f.tail;
5065                 }
5066                 // Compute the proper generic outer
5067                 Type clazzOuter = clazztype.getEnclosingType();
5068                 if (clazzOuter.hasTag(CLASS)) {
5069                     Type site;
5070                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5071                     if (clazz.hasTag(IDENT)) {
5072                         site = env.enclClass.sym.type;
5073                     } else if (clazz.hasTag(SELECT)) {
5074                         site = ((JCFieldAccess) clazz).selected.type;
5075                     } else throw new AssertionError(""+tree);
5076                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5077                         if (site.hasTag(CLASS) || site.hasTag(TYPEVAR))
5078                             site = types.asEnclosingSuper(site, clazzOuter.tsym);
5079                         if (site == null)
5080                             site = types.erasure(clazzOuter);
5081                         clazzOuter = site;
5082                     }
5083                 }
5084                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5085                                         clazztype.getMetadata());
5086             } else {
5087                 if (formals.length() != 0) {
5088                     log.error(tree.pos(),
5089                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5090                 } else {
5091                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5092                 }
5093                 owntype = types.createErrorType(tree.type);
5094             }
5095         } else if (clazztype.hasTag(ERROR)) {
5096             ErrorType parameterizedErroneous =
5097                     new ErrorType(clazztype.getOriginalType(),
5098                                   clazztype.tsym,
5099                                   clazztype.getMetadata());
5100 
5101             parameterizedErroneous.typarams_field = actuals;
5102             owntype = parameterizedErroneous;
5103         }
5104         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5105     }
5106 
5107     public void visitTypeUnion(JCTypeUnion tree) {
5108         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5109         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5110         for (JCExpression typeTree : tree.alternatives) {
5111             Type ctype = attribType(typeTree, env);
5112             ctype = chk.checkType(typeTree.pos(),
5113                           chk.checkClassType(typeTree.pos(), ctype),
5114                           syms.throwableType);
5115             if (!ctype.isErroneous()) {
5116                 //check that alternatives of a union type are pairwise
5117                 //unrelated w.r.t. subtyping
5118                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5119                     for (Type t : multicatchTypes) {
5120                         boolean sub = types.isSubtype(ctype, t);
5121                         boolean sup = types.isSubtype(t, ctype);
5122                         if (sub || sup) {
5123                             //assume 'a' <: 'b'
5124                             Type a = sub ? ctype : t;
5125                             Type b = sub ? t : ctype;
5126                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5127                         }
5128                     }
5129                 }
5130                 multicatchTypes.append(ctype);
5131                 if (all_multicatchTypes != null)
5132                     all_multicatchTypes.append(ctype);
5133             } else {
5134                 if (all_multicatchTypes == null) {
5135                     all_multicatchTypes = new ListBuffer<>();
5136                     all_multicatchTypes.appendList(multicatchTypes);
5137                 }
5138                 all_multicatchTypes.append(ctype);
5139             }
5140         }
5141         Type t = check(tree, types.lub(multicatchTypes.toList()),
5142                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5143         if (t.hasTag(CLASS)) {
5144             List<Type> alternatives =
5145                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5146             t = new UnionClassType((ClassType) t, alternatives);
5147         }
5148         tree.type = result = t;
5149     }
5150 
5151     public void visitTypeIntersection(JCTypeIntersection tree) {
5152         attribTypes(tree.bounds, env);
5153         tree.type = result = checkIntersection(tree, tree.bounds);
5154     }
5155 
5156     public void visitTypeParameter(JCTypeParameter tree) {
5157         TypeVar typeVar = (TypeVar) tree.type;
5158 
5159         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5160             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5161         }
5162 
5163         if (!typeVar.getUpperBound().isErroneous()) {
5164             //fixup type-parameter bound computed in 'attribTypeVariables'
5165             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5166         }
5167     }
5168 
5169     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5170         Set<Symbol> boundSet = new HashSet<>();
5171         if (bounds.nonEmpty()) {
5172             // accept class or interface or typevar as first bound.
5173             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5174             boundSet.add(types.erasure(bounds.head.type).tsym);
5175             if (bounds.head.type.isErroneous()) {
5176                 return bounds.head.type;
5177             }
5178             else if (bounds.head.type.hasTag(TYPEVAR)) {
5179                 // if first bound was a typevar, do not accept further bounds.
5180                 if (bounds.tail.nonEmpty()) {
5181                     log.error(bounds.tail.head.pos(),
5182                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5183                     return bounds.head.type;
5184                 }
5185             } else {
5186                 // if first bound was a class or interface, accept only interfaces
5187                 // as further bounds.
5188                 for (JCExpression bound : bounds.tail) {
5189                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5190                     if (bound.type.isErroneous()) {
5191                         bounds = List.of(bound);
5192                     }
5193                     else if (bound.type.hasTag(CLASS)) {
5194                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5195                     }
5196                 }
5197             }
5198         }
5199 
5200         if (bounds.length() == 0) {
5201             return syms.objectType;
5202         } else if (bounds.length() == 1) {
5203             return bounds.head.type;
5204         } else {
5205             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5206             // ... the variable's bound is a class type flagged COMPOUND
5207             // (see comment for TypeVar.bound).
5208             // In this case, generate a class tree that represents the
5209             // bound class, ...
5210             JCExpression extending;
5211             List<JCExpression> implementing;
5212             if (!bounds.head.type.isInterface()) {
5213                 extending = bounds.head;
5214                 implementing = bounds.tail;
5215             } else {
5216                 extending = null;
5217                 implementing = bounds;
5218             }
5219             JCClassDecl cd = make.at(tree).ClassDef(
5220                 make.Modifiers(PUBLIC | ABSTRACT),
5221                 names.empty, List.nil(),
5222                 extending, implementing, List.nil());
5223 
5224             ClassSymbol c = (ClassSymbol)owntype.tsym;
5225             Assert.check((c.flags() & COMPOUND) != 0);
5226             cd.sym = c;
5227             c.sourcefile = env.toplevel.sourcefile;
5228 
5229             // ... and attribute the bound class
5230             c.flags_field |= UNATTRIBUTED;
5231             Env<AttrContext> cenv = enter.classEnv(cd, env);
5232             typeEnvs.put(c, cenv);
5233             attribClass(c);
5234             return owntype;
5235         }
5236     }
5237 
5238     public void visitWildcard(JCWildcard tree) {
5239         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5240         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5241             ? syms.objectType
5242             : attribType(tree.inner, env);
5243         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
5244                                               tree.kind.kind,
5245                                               syms.boundClass),
5246                 KindSelector.TYP, resultInfo);
5247     }
5248 
5249     public void visitAnnotation(JCAnnotation tree) {
5250         Assert.error("should be handled in annotate");
5251     }
5252 
5253     @Override
5254     public void visitModifiers(JCModifiers tree) {
5255         //error recovery only:
5256         Assert.check(resultInfo.pkind == KindSelector.ERR);
5257 
5258         attribAnnotationTypes(tree.annotations, env);
5259     }
5260 
5261     public void visitAnnotatedType(JCAnnotatedType tree) {
5262         attribAnnotationTypes(tree.annotations, env);
5263         Type underlyingType = attribType(tree.underlyingType, env);
5264         Type annotatedType = underlyingType.preannotatedType();
5265 
5266         annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5267         result = tree.type = annotatedType;
5268     }
5269 
5270     public void visitErroneous(JCErroneous tree) {
5271         if (tree.errs != null) {
5272             WriteableScope newScope = env.info.scope;
5273 
5274             if (env.tree instanceof JCClassDecl) {
5275                 Symbol fakeOwner =
5276                     new MethodSymbol(BLOCK, names.empty, null,
5277                         env.info.scope.owner);
5278                 newScope = newScope.dupUnshared(fakeOwner);
5279             }
5280 
5281             Env<AttrContext> errEnv =
5282                     env.dup(env.tree,
5283                             env.info.dup(newScope));
5284             errEnv.info.returnResult = unknownExprInfo;
5285             for (JCTree err : tree.errs)
5286                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5287         }
5288         result = tree.type = syms.errType;
5289     }
5290 
5291     /** Default visitor method for all other trees.
5292      */
5293     public void visitTree(JCTree tree) {
5294         throw new AssertionError();
5295     }
5296 
5297     /**
5298      * Attribute an env for either a top level tree or class or module declaration.
5299      */
5300     public void attrib(Env<AttrContext> env) {
5301         switch (env.tree.getTag()) {
5302             case MODULEDEF:
5303                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5304                 break;
5305             case PACKAGEDEF:
5306                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5307                 break;
5308             default:
5309                 attribClass(env.tree.pos(), env.enclClass.sym);
5310         }
5311 
5312         annotate.flush();
5313 
5314         // Now that this tree is attributed, we can calculate the Lint configuration everywhere within it
5315         lintMapper.calculateLints(env.toplevel.sourcefile, env.tree, env.toplevel.endPositions);
5316     }
5317 
5318     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5319         try {
5320             annotate.flush();
5321             attribPackage(p);
5322         } catch (CompletionFailure ex) {
5323             chk.completionError(pos, ex);
5324         }
5325     }
5326 
5327     void attribPackage(PackageSymbol p) {
5328         attribWithLint(p,
5329                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5330     }
5331 
5332     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5333         try {
5334             annotate.flush();
5335             attribModule(m);
5336         } catch (CompletionFailure ex) {
5337             chk.completionError(pos, ex);
5338         }
5339     }
5340 
5341     void attribModule(ModuleSymbol m) {
5342         attribWithLint(m, env -> attribStat(env.tree, env));
5343     }
5344 
5345     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5346         Env<AttrContext> env = typeEnvs.get(sym);
5347 
5348         Env<AttrContext> lintEnv = env;
5349         while (lintEnv.info.lint == null)
5350             lintEnv = lintEnv.next;
5351 
5352         Lint lint = lintEnv.info.lint.augment(sym);
5353 
5354         Lint prevLint = chk.setLint(lint);
5355         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5356 
5357         try {
5358             attrib.accept(env);
5359         } finally {
5360             log.useSource(prev);
5361             chk.setLint(prevLint);
5362         }
5363     }
5364 
5365     /** Main method: attribute class definition associated with given class symbol.
5366      *  reporting completion failures at the given position.
5367      *  @param pos The source position at which completion errors are to be
5368      *             reported.
5369      *  @param c   The class symbol whose definition will be attributed.
5370      */
5371     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5372         try {
5373             annotate.flush();
5374             attribClass(c);
5375         } catch (CompletionFailure ex) {
5376             chk.completionError(pos, ex);
5377         }
5378     }
5379 
5380     /** Attribute class definition associated with given class symbol.
5381      *  @param c   The class symbol whose definition will be attributed.
5382      */
5383     void attribClass(ClassSymbol c) throws CompletionFailure {
5384         if (c.type.hasTag(ERROR)) return;
5385 
5386         // Check for cycles in the inheritance graph, which can arise from
5387         // ill-formed class files.
5388         chk.checkNonCyclic(null, c.type);
5389 
5390         Type st = types.supertype(c.type);
5391         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5392             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0) {
5393             // First, attribute superclass.
5394             if (st.hasTag(CLASS))
5395                 attribClass((ClassSymbol)st.tsym);
5396 
5397             // Next attribute owner, if it is a class.
5398             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5399                 attribClass((ClassSymbol)c.owner);
5400 
5401             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5402         }
5403 
5404         // The previous operations might have attributed the current class
5405         // if there was a cycle. So we test first whether the class is still
5406         // UNATTRIBUTED.
5407         if ((c.flags_field & UNATTRIBUTED) != 0) {
5408             c.flags_field &= ~UNATTRIBUTED;
5409 
5410             // Get environment current at the point of class definition.
5411             Env<AttrContext> env = typeEnvs.get(c);
5412 
5413             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5414             // because the annotations were not available at the time the env was created. Therefore,
5415             // we look up the environment chain for the first enclosing environment for which the
5416             // lint value is set. Typically, this is the parent env, but might be further if there
5417             // are any envs created as a result of TypeParameter nodes.
5418             Env<AttrContext> lintEnv = env;
5419             while (lintEnv.info.lint == null)
5420                 lintEnv = lintEnv.next;
5421 
5422             // Having found the enclosing lint value, we can initialize the lint value for this class
5423             env.info.lint = lintEnv.info.lint.augment(c);
5424 
5425             Lint prevLint = chk.setLint(env.info.lint);
5426             JavaFileObject prev = log.useSource(c.sourcefile);
5427             ResultInfo prevReturnRes = env.info.returnResult;
5428 
5429             try {
5430                 if (c.isSealed() &&
5431                         !c.isEnum() &&
5432                         !c.isPermittedExplicit &&
5433                         c.getPermittedSubclasses().isEmpty()) {
5434                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5435                 }
5436 
5437                 if (c.isSealed()) {
5438                     Set<Symbol> permittedTypes = new HashSet<>();
5439                     boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5440                     for (Type subType : c.getPermittedSubclasses()) {
5441                         if (subType.isErroneous()) {
5442                             // the type already caused errors, don't produce more potentially misleading errors
5443                             continue;
5444                         }
5445                         boolean isTypeVar = false;
5446                         if (subType.getTag() == TYPEVAR) {
5447                             isTypeVar = true; //error recovery
5448                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5449                                     Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subType)));
5450                         }
5451                         if (subType.tsym.isAnonymous() && !c.isEnum()) {
5452                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5453                         }
5454                         if (permittedTypes.contains(subType.tsym)) {
5455                             DiagnosticPosition pos =
5456                                     env.enclClass.permitting.stream()
5457                                             .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subType.tsym, permittedExpr, true) != null)
5458                                             .limit(2).collect(List.collector()).get(1);
5459                             log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subType)));
5460                         } else {
5461                             permittedTypes.add(subType.tsym);
5462                         }
5463                         if (sealedInUnnamed) {
5464                             if (subType.tsym.packge() != c.packge()) {
5465                                 log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5466                                         Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5467                                 );
5468                             }
5469                         } else if (subType.tsym.packge().modle != c.packge().modle) {
5470                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5471                                     Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5472                             );
5473                         }
5474                         if (subType.tsym == c.type.tsym || types.isSuperType(subType, c.type)) {
5475                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, ((JCClassDecl)env.tree).permitting),
5476                                     Errors.InvalidPermitsClause(
5477                                             subType.tsym == c.type.tsym ?
5478                                                     Fragments.MustNotBeSameClass :
5479                                                     Fragments.MustNotBeSupertype(subType)
5480                                     )
5481                             );
5482                         } else if (!isTypeVar) {
5483                             boolean thisIsASuper = types.directSupertypes(subType)
5484                                                         .stream()
5485                                                         .anyMatch(d -> d.tsym == c);
5486                             if (!thisIsASuper) {
5487                                 if(c.isInterface()) {
5488                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5489                                             Errors.InvalidPermitsClause(Fragments.DoesntImplementSealed(kindName(subType.tsym), subType)));
5490                                 } else {
5491                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5492                                             Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subType)));
5493                                 }
5494                             }
5495                         }
5496                     }
5497                 }
5498 
5499                 List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5500                                                       .stream()
5501                                                       .filter(s -> s.tsym.isSealed())
5502                                                       .map(s -> (ClassSymbol) s.tsym)
5503                                                       .collect(List.collector());
5504 
5505                 if (sealedSupers.isEmpty()) {
5506                     if ((c.flags_field & Flags.NON_SEALED) != 0) {
5507                         boolean hasErrorSuper = false;
5508 
5509                         hasErrorSuper |= types.directSupertypes(c.type)
5510                                               .stream()
5511                                               .anyMatch(s -> s.tsym.kind == Kind.ERR);
5512 
5513                         ClassType ct = (ClassType) c.type;
5514 
5515                         hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5516 
5517                         if (!hasErrorSuper) {
5518                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5519                         }
5520                     }
5521                 } else {
5522                     if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5523                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5524                     }
5525 
5526                     if (!c.type.isCompound()) {
5527                         for (ClassSymbol supertypeSym : sealedSupers) {
5528                             if (!supertypeSym.isPermittedSubclass(c.type.tsym)) {
5529                                 log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5530                             }
5531                         }
5532                         if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5533                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5534                                     c.isInterface() ?
5535                                             Errors.NonSealedOrSealedExpected :
5536                                             Errors.NonSealedSealedOrFinalExpected);
5537                         }
5538                     }
5539                 }
5540 
5541                 env.info.returnResult = null;
5542                 // java.lang.Enum may not be subclassed by a non-enum
5543                 if (st.tsym == syms.enumSym &&
5544                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5545                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5546 
5547                 // Enums may not be extended by source-level classes
5548                 if (st.tsym != null &&
5549                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5550                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5551                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5552                 }
5553 
5554                 if (rs.isSerializable(c.type)) {
5555                     env.info.isSerializable = true;
5556                 }
5557 
5558                 attribClassBody(env, c);
5559 
5560                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5561                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5562                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5563                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5564 
5565                 if (c.isImplicit()) {
5566                     chk.checkHasMain(env.tree.pos(), c);
5567                 }
5568             } finally {
5569                 env.info.returnResult = prevReturnRes;
5570                 log.useSource(prev);
5571                 chk.setLint(prevLint);
5572             }
5573 
5574         }
5575     }
5576 
5577     public void visitImport(JCImport tree) {
5578         // nothing to do
5579     }
5580 
5581     public void visitModuleDef(JCModuleDecl tree) {
5582         tree.sym.completeUsesProvides();
5583         ModuleSymbol msym = tree.sym;
5584         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5585         Lint prevLint = chk.setLint(lint);
5586         try {
5587             chk.checkModuleName(tree);
5588             chk.checkDeprecatedAnnotation(tree, msym);
5589         } finally {
5590             chk.setLint(prevLint);
5591         }
5592     }
5593 
5594     /** Finish the attribution of a class. */
5595     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5596         JCClassDecl tree = (JCClassDecl)env.tree;
5597         Assert.check(c == tree.sym);
5598 
5599         // Validate type parameters, supertype and interfaces.
5600         attribStats(tree.typarams, env);
5601         if (!c.isAnonymous()) {
5602             //already checked if anonymous
5603             chk.validate(tree.typarams, env);
5604             chk.validate(tree.extending, env);
5605             chk.validate(tree.implementing, env);
5606         }
5607 
5608         chk.checkRequiresIdentity(tree, env.info.lint);
5609 
5610         c.markAbstractIfNeeded(types);
5611 
5612         // If this is a non-abstract class, check that it has no abstract
5613         // methods or unimplemented methods of an implemented interface.
5614         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
5615             chk.checkAllDefined(tree.pos(), c);
5616         }
5617 
5618         if ((c.flags() & ANNOTATION) != 0) {
5619             if (tree.implementing.nonEmpty())
5620                 log.error(tree.implementing.head.pos(),
5621                           Errors.CantExtendIntfAnnotation);
5622             if (tree.typarams.nonEmpty()) {
5623                 log.error(tree.typarams.head.pos(),
5624                           Errors.IntfAnnotationCantHaveTypeParams(c));
5625             }
5626 
5627             // If this annotation type has a @Repeatable, validate
5628             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
5629             // If this annotation type has a @Repeatable, validate
5630             if (repeatable != null) {
5631                 // get diagnostic position for error reporting
5632                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
5633                 Assert.checkNonNull(cbPos);
5634 
5635                 chk.validateRepeatable(c, repeatable, cbPos);
5636             }
5637         } else {
5638             // Check that all extended classes and interfaces
5639             // are compatible (i.e. no two define methods with same arguments
5640             // yet different return types).  (JLS 8.4.8.3)
5641             chk.checkCompatibleSupertypes(tree.pos(), c.type);
5642             chk.checkDefaultMethodClashes(tree.pos(), c.type);
5643             chk.checkPotentiallyAmbiguousOverloads(tree, c.type);
5644         }
5645 
5646         // Check that class does not import the same parameterized interface
5647         // with two different argument lists.
5648         chk.checkClassBounds(tree.pos(), c.type);
5649 
5650         tree.type = c.type;
5651 
5652         for (List<JCTypeParameter> l = tree.typarams;
5653              l.nonEmpty(); l = l.tail) {
5654              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
5655         }
5656 
5657         // Check that a generic class doesn't extend Throwable
5658         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
5659             log.error(tree.extending.pos(), Errors.GenericThrowable);
5660 
5661         // Check that all methods which implement some
5662         // method conform to the method they implement.
5663         chk.checkImplementations(tree);
5664 
5665         //check that a resource implementing AutoCloseable cannot throw InterruptedException
5666         checkAutoCloseable(tree.pos(), env, c.type);
5667 
5668         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
5669             // Attribute declaration
5670             attribStat(l.head, env);
5671             // Check that declarations in inner classes are not static (JLS 8.1.2)
5672             // Make an exception for static constants.
5673             if (!allowRecords &&
5674                     c.owner.kind != PCK &&
5675                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
5676                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
5677                 VarSymbol sym = null;
5678                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
5679                 if (sym == null ||
5680                         sym.kind != VAR ||
5681                         sym.getConstValue() == null)
5682                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
5683             }
5684         }
5685 
5686         // Check for proper placement of super()/this() calls.
5687         chk.checkSuperInitCalls(tree);
5688 
5689         // Check for cycles among non-initial constructors.
5690         chk.checkCyclicConstructors(tree);
5691 
5692         // Check for cycles among annotation elements.
5693         chk.checkNonCyclicElements(tree);
5694 
5695         // Check for proper use of serialVersionUID and other
5696         // serialization-related fields and methods
5697         if (env.info.lint.isEnabled(LintCategory.SERIAL)
5698                 && rs.isSerializable(c.type)
5699                 && !c.isAnonymous()) {
5700             chk.checkSerialStructure(tree, c);
5701         }
5702         // Correctly organize the positions of the type annotations
5703         typeAnnotations.organizeTypeAnnotationsBodies(tree);
5704 
5705         // Check type annotations applicability rules
5706         validateTypeAnnotations(tree, false);
5707     }
5708         // where
5709         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
5710         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
5711             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
5712                 if (types.isSameType(al.head.annotationType.type, t))
5713                     return al.head.pos();
5714             }
5715 
5716             return null;
5717         }
5718 
5719     private Type capture(Type type) {
5720         return types.capture(type);
5721     }
5722 
5723     private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
5724         if (type.isErroneous()) {
5725             tree.vartype = make.at(tree.pos()).Erroneous();
5726         } else if (tree.declaredUsingVar()) {
5727             Assert.check(tree.typePos != Position.NOPOS);
5728             tree.vartype = make.at(tree.typePos).Type(type);
5729         } else {
5730             tree.vartype = make.at(tree.pos()).Type(type);
5731         }
5732     }
5733 
5734     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
5735         tree.accept(new TypeAnnotationsValidator(sigOnly));
5736     }
5737     //where
5738     private final class TypeAnnotationsValidator extends TreeScanner {
5739 
5740         private final boolean sigOnly;
5741         public TypeAnnotationsValidator(boolean sigOnly) {
5742             this.sigOnly = sigOnly;
5743         }
5744 
5745         public void visitAnnotation(JCAnnotation tree) {
5746             chk.validateTypeAnnotation(tree, null, false);
5747             super.visitAnnotation(tree);
5748         }
5749         public void visitAnnotatedType(JCAnnotatedType tree) {
5750             if (!tree.underlyingType.type.isErroneous()) {
5751                 super.visitAnnotatedType(tree);
5752             }
5753         }
5754         public void visitTypeParameter(JCTypeParameter tree) {
5755             chk.validateTypeAnnotations(tree.annotations, tree.type.tsym, true);
5756             scan(tree.bounds);
5757             // Don't call super.
5758             // This is needed because above we call validateTypeAnnotation with
5759             // false, which would forbid annotations on type parameters.
5760             // super.visitTypeParameter(tree);
5761         }
5762         public void visitMethodDef(JCMethodDecl tree) {
5763             if (tree.recvparam != null &&
5764                     !tree.recvparam.vartype.type.isErroneous()) {
5765                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
5766             }
5767             if (tree.restype != null && tree.restype.type != null) {
5768                 validateAnnotatedType(tree.restype, tree.restype.type);
5769             }
5770             if (sigOnly) {
5771                 scan(tree.mods);
5772                 scan(tree.restype);
5773                 scan(tree.typarams);
5774                 scan(tree.recvparam);
5775                 scan(tree.params);
5776                 scan(tree.thrown);
5777             } else {
5778                 scan(tree.defaultValue);
5779                 scan(tree.body);
5780             }
5781         }
5782         public void visitVarDef(final JCVariableDecl tree) {
5783             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
5784             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
5785                 validateAnnotatedType(tree.vartype, tree.sym.type);
5786             scan(tree.mods);
5787             scan(tree.vartype);
5788             if (!sigOnly) {
5789                 scan(tree.init);
5790             }
5791         }
5792         public void visitTypeCast(JCTypeCast tree) {
5793             if (tree.clazz != null && tree.clazz.type != null)
5794                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5795             super.visitTypeCast(tree);
5796         }
5797         public void visitTypeTest(JCInstanceOf tree) {
5798             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
5799                 validateAnnotatedType(tree.pattern, tree.pattern.type);
5800             super.visitTypeTest(tree);
5801         }
5802         public void visitNewClass(JCNewClass tree) {
5803             if (tree.clazz != null && tree.clazz.type != null) {
5804                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
5805                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
5806                             tree.clazz.type.tsym);
5807                 }
5808                 if (tree.def != null) {
5809                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
5810                 }
5811 
5812                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5813             }
5814             super.visitNewClass(tree);
5815         }
5816         public void visitNewArray(JCNewArray tree) {
5817             if (tree.elemtype != null && tree.elemtype.type != null) {
5818                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
5819                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
5820                             tree.elemtype.type.tsym);
5821                 }
5822                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
5823             }
5824             super.visitNewArray(tree);
5825         }
5826         public void visitClassDef(JCClassDecl tree) {
5827             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
5828             if (sigOnly) {
5829                 scan(tree.mods);
5830                 scan(tree.typarams);
5831                 scan(tree.extending);
5832                 scan(tree.implementing);
5833             }
5834             for (JCTree member : tree.defs) {
5835                 if (member.hasTag(Tag.CLASSDEF)) {
5836                     continue;
5837                 }
5838                 scan(member);
5839             }
5840         }
5841         public void visitBlock(JCBlock tree) {
5842             if (!sigOnly) {
5843                 scan(tree.stats);
5844             }
5845         }
5846 
5847         /* I would want to model this after
5848          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
5849          * and override visitSelect and visitTypeApply.
5850          * However, we only set the annotated type in the top-level type
5851          * of the symbol.
5852          * Therefore, we need to override each individual location where a type
5853          * can occur.
5854          */
5855         private void validateAnnotatedType(final JCTree errtree, final Type type) {
5856             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
5857 
5858             if (type.isPrimitiveOrVoid()) {
5859                 return;
5860             }
5861 
5862             JCTree enclTr = errtree;
5863             Type enclTy = type;
5864 
5865             boolean repeat = true;
5866             while (repeat) {
5867                 if (enclTr.hasTag(TYPEAPPLY)) {
5868                     List<Type> tyargs = enclTy.getTypeArguments();
5869                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
5870                     if (trargs.length() > 0) {
5871                         // Nothing to do for diamonds
5872                         if (tyargs.length() == trargs.length()) {
5873                             for (int i = 0; i < tyargs.length(); ++i) {
5874                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
5875                             }
5876                         }
5877                         // If the lengths don't match, it's either a diamond
5878                         // or some nested type that redundantly provides
5879                         // type arguments in the tree.
5880                     }
5881 
5882                     // Look at the clazz part of a generic type
5883                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
5884                 }
5885 
5886                 if (enclTr.hasTag(SELECT)) {
5887                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
5888                     if (enclTy != null &&
5889                             !enclTy.hasTag(NONE)) {
5890                         enclTy = enclTy.getEnclosingType();
5891                     }
5892                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
5893                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
5894                     if (enclTy == null || enclTy.hasTag(NONE)) {
5895                         ListBuffer<Attribute.TypeCompound> onlyTypeAnnotationsBuf = new ListBuffer<>();
5896                         for (JCAnnotation an : at.getAnnotations()) {
5897                             if (chk.isTypeAnnotation(an, false)) {
5898                                 onlyTypeAnnotationsBuf.add((Attribute.TypeCompound) an.attribute);
5899                             }
5900                         }
5901                         List<Attribute.TypeCompound> onlyTypeAnnotations = onlyTypeAnnotationsBuf.toList();
5902                         if (!onlyTypeAnnotations.isEmpty()) {
5903                             Fragment annotationFragment = onlyTypeAnnotations.size() == 1 ?
5904                                     Fragments.TypeAnnotation1(onlyTypeAnnotations.head) :
5905                                     Fragments.TypeAnnotation(onlyTypeAnnotations);
5906                             JCDiagnostic.AnnotatedType annotatedType = new JCDiagnostic.AnnotatedType(
5907                                     type.stripMetadata().annotatedType(onlyTypeAnnotations));
5908                             log.error(at.underlyingType.pos(), Errors.TypeAnnotationInadmissible(annotationFragment,
5909                                     type.tsym.owner, annotatedType));
5910                         }
5911                         repeat = false;
5912                     }
5913                     enclTr = at.underlyingType;
5914                     // enclTy doesn't need to be changed
5915                 } else if (enclTr.hasTag(IDENT)) {
5916                     repeat = false;
5917                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
5918                     JCWildcard wc = (JCWildcard) enclTr;
5919                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
5920                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
5921                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
5922                     } else {
5923                         // Nothing to do for UNBOUND
5924                     }
5925                     repeat = false;
5926                 } else if (enclTr.hasTag(TYPEARRAY)) {
5927                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
5928                     validateAnnotatedType(art.getType(), art.elemtype.type);
5929                     repeat = false;
5930                 } else if (enclTr.hasTag(TYPEUNION)) {
5931                     JCTypeUnion ut = (JCTypeUnion) enclTr;
5932                     for (JCTree t : ut.getTypeAlternatives()) {
5933                         validateAnnotatedType(t, t.type);
5934                     }
5935                     repeat = false;
5936                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
5937                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
5938                     for (JCTree t : it.getBounds()) {
5939                         validateAnnotatedType(t, t.type);
5940                     }
5941                     repeat = false;
5942                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
5943                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
5944                     repeat = false;
5945                 } else {
5946                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
5947                             " within: "+ errtree + " with kind: " + errtree.getKind());
5948                 }
5949             }
5950         }
5951 
5952         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
5953                 Symbol sym) {
5954             // Ensure that no declaration annotations are present.
5955             // Note that a tree type might be an AnnotatedType with
5956             // empty annotations, if only declaration annotations were given.
5957             // This method will raise an error for such a type.
5958             for (JCAnnotation ai : annotations) {
5959                 if (!ai.type.isErroneous() &&
5960                         typeAnnotations.annotationTargetType(ai, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
5961                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
5962                 }
5963             }
5964         }
5965     }
5966 
5967     // <editor-fold desc="post-attribution visitor">
5968 
5969     /**
5970      * Handle missing types/symbols in an AST. This routine is useful when
5971      * the compiler has encountered some errors (which might have ended up
5972      * terminating attribution abruptly); if the compiler is used in fail-over
5973      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
5974      * prevents NPE to be propagated during subsequent compilation steps.
5975      */
5976     public void postAttr(JCTree tree) {
5977         new PostAttrAnalyzer().scan(tree);
5978     }
5979 
5980     class PostAttrAnalyzer extends TreeScanner {
5981 
5982         private void initTypeIfNeeded(JCTree that) {
5983             if (that.type == null) {
5984                 if (that.hasTag(METHODDEF)) {
5985                     that.type = dummyMethodType((JCMethodDecl)that);
5986                 } else {
5987                     that.type = syms.unknownType;
5988                 }
5989             }
5990         }
5991 
5992         /* Construct a dummy method type. If we have a method declaration,
5993          * and the declared return type is void, then use that return type
5994          * instead of UNKNOWN to avoid spurious error messages in lambda
5995          * bodies (see:JDK-8041704).
5996          */
5997         private Type dummyMethodType(JCMethodDecl md) {
5998             Type restype = syms.unknownType;
5999             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
6000                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
6001                 if (prim.typetag == VOID)
6002                     restype = syms.voidType;
6003             }
6004             return new MethodType(List.nil(), restype,
6005                                   List.nil(), syms.methodClass);
6006         }
6007         private Type dummyMethodType() {
6008             return dummyMethodType(null);
6009         }
6010 
6011         @Override
6012         public void scan(JCTree tree) {
6013             if (tree == null) return;
6014             if (tree instanceof JCExpression) {
6015                 initTypeIfNeeded(tree);
6016             }
6017             super.scan(tree);
6018         }
6019 
6020         @Override
6021         public void visitIdent(JCIdent that) {
6022             if (that.sym == null) {
6023                 that.sym = syms.unknownSymbol;
6024             }
6025         }
6026 
6027         @Override
6028         public void visitSelect(JCFieldAccess that) {
6029             if (that.sym == null) {
6030                 that.sym = syms.unknownSymbol;
6031             }
6032             super.visitSelect(that);
6033         }
6034 
6035         @Override
6036         public void visitClassDef(JCClassDecl that) {
6037             initTypeIfNeeded(that);
6038             if (that.sym == null) {
6039                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
6040             }
6041             super.visitClassDef(that);
6042         }
6043 
6044         @Override
6045         public void visitMethodDef(JCMethodDecl that) {
6046             initTypeIfNeeded(that);
6047             if (that.sym == null) {
6048                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
6049             }
6050             super.visitMethodDef(that);
6051         }
6052 
6053         @Override
6054         public void visitVarDef(JCVariableDecl that) {
6055             initTypeIfNeeded(that);
6056             if (that.sym == null) {
6057                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
6058                 that.sym.adr = 0;
6059             }
6060             if (that.vartype == null) {
6061                 that.vartype = make.at(Position.NOPOS).Erroneous();
6062             }
6063             super.visitVarDef(that);
6064         }
6065 
6066         @Override
6067         public void visitBindingPattern(JCBindingPattern that) {
6068             initTypeIfNeeded(that);
6069             initTypeIfNeeded(that.var);
6070             if (that.var.sym == null) {
6071                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6072                 that.var.sym.adr = 0;
6073             }
6074             super.visitBindingPattern(that);
6075         }
6076 
6077         @Override
6078         public void visitRecordPattern(JCRecordPattern that) {
6079             initTypeIfNeeded(that);
6080             if (that.record == null) {
6081                 that.record = new ClassSymbol(0, TreeInfo.name(that.deconstructor),
6082                                               that.type, syms.noSymbol);
6083             }
6084             if (that.fullComponentTypes == null) {
6085                 that.fullComponentTypes = List.nil();
6086             }
6087             super.visitRecordPattern(that);
6088         }
6089 
6090         @Override
6091         public void visitNewClass(JCNewClass that) {
6092             if (that.constructor == null) {
6093                 that.constructor = new MethodSymbol(0, names.init,
6094                         dummyMethodType(), syms.noSymbol);
6095             }
6096             if (that.constructorType == null) {
6097                 that.constructorType = syms.unknownType;
6098             }
6099             super.visitNewClass(that);
6100         }
6101 
6102         @Override
6103         public void visitAssignop(JCAssignOp that) {
6104             if (that.operator == null) {
6105                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6106                         -1, syms.noSymbol);
6107             }
6108             super.visitAssignop(that);
6109         }
6110 
6111         @Override
6112         public void visitBinary(JCBinary that) {
6113             if (that.operator == null) {
6114                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6115                         -1, syms.noSymbol);
6116             }
6117             super.visitBinary(that);
6118         }
6119 
6120         @Override
6121         public void visitUnary(JCUnary that) {
6122             if (that.operator == null) {
6123                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6124                         -1, syms.noSymbol);
6125             }
6126             super.visitUnary(that);
6127         }
6128 
6129         @Override
6130         public void visitReference(JCMemberReference that) {
6131             super.visitReference(that);
6132             if (that.sym == null) {
6133                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6134                         syms.noSymbol);
6135             }
6136         }
6137     }
6138     // </editor-fold>
6139 
6140     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6141         new TreeScanner() {
6142             Symbol packge = pkg;
6143             @Override
6144             public void visitIdent(JCIdent that) {
6145                 that.sym = packge;
6146             }
6147 
6148             @Override
6149             public void visitSelect(JCFieldAccess that) {
6150                 that.sym = packge;
6151                 packge = packge.owner;
6152                 super.visitSelect(that);
6153             }
6154         }.scan(pid);
6155     }
6156 
6157 }