1 /*
   2  * Copyright (c) 1999, 2026, 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     final boolean captureMRefReturnType;
 129 
 130     public static Attr instance(Context context) {
 131         Attr instance = context.get(attrKey);
 132         if (instance == null)
 133             instance = new Attr(context);
 134         return instance;
 135     }
 136 
 137     @SuppressWarnings("this-escape")
 138     protected Attr(Context context) {
 139         context.put(attrKey, this);
 140 
 141         names = Names.instance(context);
 142         log = Log.instance(context);
 143         lintMapper = LintMapper.instance(context);
 144         syms = Symtab.instance(context);
 145         rs = Resolve.instance(context);
 146         operators = Operators.instance(context);
 147         chk = Check.instance(context);
 148         flow = Flow.instance(context);
 149         memberEnter = MemberEnter.instance(context);
 150         typeEnter = TypeEnter.instance(context);
 151         make = TreeMaker.instance(context);
 152         enter = Enter.instance(context);
 153         infer = Infer.instance(context);
 154         analyzer = Analyzer.instance(context);
 155         deferredAttr = DeferredAttr.instance(context);
 156         cfolder = ConstFold.instance(context);
 157         target = Target.instance(context);
 158         types = Types.instance(context);
 159         preview = Preview.instance(context);
 160         diags = JCDiagnostic.Factory.instance(context);
 161         annotate = Annotate.instance(context);
 162         typeAnnotations = TypeAnnotations.instance(context);
 163         typeEnvs = TypeEnvs.instance(context);
 164         dependencies = Dependencies.instance(context);
 165         argumentAttr = ArgumentAttr.instance(context);
 166         matchBindingsComputer = MatchBindingsComputer.instance(context);
 167         attrRecover = AttrRecover.instance(context);
 168 
 169         Options options = Options.instance(context);
 170 
 171         Source source = Source.instance(context);
 172         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 173         allowRecords = Feature.RECORDS.allowedInSource(source);
 174         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 175                              Feature.PATTERN_SWITCH.allowedInSource(source);
 176         allowUnconditionalPatternsInstanceOf =
 177                              Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 178         sourceName = source.name;
 179         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 180         captureMRefReturnType = Source.Feature.CAPTURE_MREF_RETURN_TYPE.allowedInSource(source);
 181 
 182         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 183         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 184         unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
 185         methodAttrInfo = new MethodAttrInfo();
 186         unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
 187         unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
 188         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
 189         initBlockType = new MethodType(List.nil(), syms.voidType, List.nil(), syms.methodClass);
 190     }
 191 
 192     /** Switch: reifiable types in instanceof enabled?
 193      */
 194     boolean allowReifiableTypesInInstanceof;
 195 
 196     /** Are records allowed
 197      */
 198     private final boolean allowRecords;
 199 
 200     /** Are patterns in switch allowed
 201      */
 202     private final boolean allowPatternSwitch;
 203 
 204     /** Are unconditional patterns in instanceof allowed
 205      */
 206     private final boolean allowUnconditionalPatternsInstanceOf;
 207 
 208     /**
 209      * Switch: warn about use of variable before declaration?
 210      * RFE: 6425594
 211      */
 212     boolean useBeforeDeclarationWarning;
 213 
 214     /**
 215      * Switch: name of source level; used for error reporting.
 216      */
 217     String sourceName;
 218 
 219     /** Check kind and type of given tree against protokind and prototype.
 220      *  If check succeeds, store type in tree and return it.
 221      *  If check fails, store errType in tree and return it.
 222      *  No checks are performed if the prototype is a method type.
 223      *  It is not necessary in this case since we know that kind and type
 224      *  are correct.
 225      *
 226      *  @param tree     The tree whose kind and type is checked
 227      *  @param found    The computed type of the tree
 228      *  @param ownkind  The computed kind of the tree
 229      *  @param resultInfo  The expected result of the tree
 230      */
 231     Type check(final JCTree tree,
 232                final Type found,
 233                final KindSelector ownkind,
 234                final ResultInfo resultInfo) {
 235         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 236         Type owntype;
 237         boolean shouldCheck = !found.hasTag(ERROR) &&
 238                 !resultInfo.pt.hasTag(METHOD) &&
 239                 !resultInfo.pt.hasTag(FORALL);
 240         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 241             log.error(tree.pos(),
 242                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 243                                             ownkind.kindNames()));
 244             owntype = types.createErrorType(found);
 245         } else if (inferenceContext.free(found)) {
 246             //delay the check if there are inference variables in the found type
 247             //this means we are dealing with a partially inferred poly expression
 248             owntype = shouldCheck ? resultInfo.pt : found;
 249             if (resultInfo.checkMode.installPostInferenceHook()) {
 250                 inferenceContext.addFreeTypeListener(List.of(found),
 251                         instantiatedContext -> {
 252                             ResultInfo pendingResult =
 253                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 254                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 255                         });
 256             }
 257         } else {
 258             owntype = shouldCheck ?
 259             resultInfo.check(tree, found) :
 260             found;
 261         }
 262         if (resultInfo.checkMode.updateTreeType()) {
 263             tree.type = owntype;
 264         }
 265         return owntype;
 266     }
 267 
 268     /** Is given blank final variable assignable, i.e. in a scope where it
 269      *  may be assigned to even though it is final?
 270      *  @param v      The blank final variable.
 271      *  @param env    The current environment.
 272      */
 273     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 274         Symbol owner = env.info.scope.owner;
 275            // owner refers to the innermost variable, method or
 276            // initializer block declaration at this point.
 277         boolean isAssignable =
 278             v.owner == owner
 279             ||
 280             ((owner.name == names.init ||    // i.e. we are in a constructor
 281               owner.kind == VAR ||           // i.e. we are in a variable initializer
 282               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 283              &&
 284              v.owner == owner.owner
 285              &&
 286              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 287         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 288         return isAssignable & !insideCompactConstructor;
 289     }
 290 
 291     /** Check that variable can be assigned to.
 292      *  @param pos    The current source code position.
 293      *  @param v      The assigned variable
 294      *  @param base   If the variable is referred to in a Select, the part
 295      *                to the left of the `.', null otherwise.
 296      *  @param env    The current environment.
 297      */
 298     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 299         if (v.name == names._this) {
 300             log.error(pos, Errors.CantAssignValToThis);
 301             return;
 302         }
 303         if ((v.flags() & FINAL) != 0 &&
 304             ((v.flags() & HASINIT) != 0
 305              ||
 306              !((base == null ||
 307                TreeInfo.isThisQualifier(base)) &&
 308                isAssignableAsBlankFinal(v, env)))) {
 309             if (v.isResourceVariable()) { //TWR resource
 310                 log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
 311             } else {
 312                 log.error(pos, Errors.CantAssignValToVar(Flags.toSource(v.flags() & (STATIC | FINAL)), v));
 313             }
 314             return;
 315         }
 316 
 317         // Check instance field assignments that appear in constructor prologues
 318         if (rs.isEarlyReference(env, base, v)) {
 319 
 320             // Field may not be inherited from a superclass
 321             if (v.owner != env.enclClass.sym) {
 322                 log.error(pos, Errors.CantRefBeforeCtorCalled(v));
 323                 return;
 324             }
 325 
 326             // Field may not have an initializer
 327             if ((v.flags() & HASINIT) != 0) {
 328                 log.error(pos, Errors.CantAssignInitializedBeforeCtorCalled(v));
 329                 return;
 330             }
 331         }
 332     }
 333 
 334     /** Does tree represent a static reference to an identifier?
 335      *  It is assumed that tree is either a SELECT or an IDENT.
 336      *  We have to weed out selects from non-type names here.
 337      *  @param tree    The candidate tree.
 338      */
 339     boolean isStaticReference(JCTree tree) {
 340         if (tree.hasTag(SELECT)) {
 341             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 342             if (lsym == null || lsym.kind != TYP) {
 343                 return false;
 344             }
 345         }
 346         return true;
 347     }
 348 
 349     /** Is this symbol a type?
 350      */
 351     static boolean isType(Symbol sym) {
 352         return sym != null && sym.kind == TYP;
 353     }
 354 
 355     /** Attribute a parsed identifier.
 356      * @param tree Parsed identifier name
 357      * @param topLevel The toplevel to use
 358      */
 359     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 360         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 361         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 362                                            syms.errSymbol.name,
 363                                            null, null, null, null);
 364         localEnv.enclClass.sym = syms.errSymbol;
 365         return attribIdent(tree, localEnv);
 366     }
 367 
 368     /** Attribute a parsed identifier.
 369      * @param tree Parsed identifier name
 370      * @param env The env to use
 371      */
 372     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 373         return tree.accept(identAttributer, env);
 374     }
 375     // where
 376         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 377         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 378             @Override @DefinedBy(Api.COMPILER_TREE)
 379             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 380                 Symbol site = visit(node.getExpression(), env);
 381                 if (site == null || site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 382                     return site;
 383                 Name name = (Name)node.getIdentifier();
 384                 if (site.kind == PCK) {
 385                     env.toplevel.packge = (PackageSymbol)site;
 386                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 387                             KindSelector.TYP_PCK);
 388                 } else {
 389                     env.enclClass.sym = (ClassSymbol)site;
 390                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 391                 }
 392             }
 393 
 394             @Override @DefinedBy(Api.COMPILER_TREE)
 395             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 396                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 397             }
 398         }
 399 
 400     public Type coerce(Type etype, Type ttype) {
 401         return cfolder.coerce(etype, ttype);
 402     }
 403 
 404     public Type attribType(JCTree node, TypeSymbol sym) {
 405         Env<AttrContext> env = typeEnvs.get(sym);
 406         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 407         return attribTree(node, localEnv, unknownTypeInfo);
 408     }
 409 
 410     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 411         // Attribute qualifying package or class.
 412         JCFieldAccess s = tree.qualid;
 413         return attribTree(s.selected, env,
 414                           new ResultInfo(tree.staticImport ?
 415                                          KindSelector.TYP : KindSelector.TYP_PCK,
 416                        Type.noType));
 417     }
 418 
 419     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 420         return attribToTree(expr, env, tree, unknownExprInfo);
 421     }
 422 
 423     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 424         return attribToTree(stmt, env, tree, statInfo);
 425     }
 426 
 427     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 428         breakTree = tree;
 429         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 430         try {
 431             deferredAttr.attribSpeculative(root, env, resultInfo,
 432                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 433                     argumentAttr.withLocalCacheContext());
 434             attrRecover.doRecovery();
 435         } catch (BreakAttr b) {
 436             return b.env;
 437         } catch (AssertionError ae) {
 438             if (ae.getCause() instanceof BreakAttr breakAttr) {
 439                 return breakAttr.env;
 440             } else {
 441                 throw ae;
 442             }
 443         } finally {
 444             breakTree = null;
 445             log.useSource(prev);
 446         }
 447         return env;
 448     }
 449 
 450     public <R> R runWithAttributedMethod(Env<AttrContext> env, JCMethodDecl tree, Function<JCBlock, R> attributedAction) {
 451         JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 452         try {
 453             annotate.queueScanTreeAndTypeAnnotate(tree.body, env, tree.sym);
 454             annotate.flush();
 455             JCBlock dupTree = (JCBlock)deferredAttr.attribSpeculative(tree.body, env, statInfo,
 456                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 457                     argumentAttr.withLocalCacheContext());
 458             return attributedAction.apply(dupTree);
 459         } finally {
 460             attrRecover.doRecovery();
 461             log.useSource(prevSource);
 462         }
 463     }
 464 
 465     private JCTree breakTree = null;
 466 
 467     private static class BreakAttr extends RuntimeException {
 468         static final long serialVersionUID = -6924771130405446405L;
 469         private transient Env<AttrContext> env;
 470         private BreakAttr(Env<AttrContext> env) {
 471             this.env = env;
 472         }
 473     }
 474 
 475     /**
 476      * Mode controlling behavior of Attr.Check
 477      */
 478     enum CheckMode {
 479 
 480         NORMAL,
 481 
 482         /**
 483          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 484          * that the captured var cache in {@code InferenceContext} will be used in read-only
 485          * mode when performing inference checks.
 486          */
 487         NO_TREE_UPDATE {
 488             @Override
 489             public boolean updateTreeType() {
 490                 return false;
 491             }
 492         },
 493         /**
 494          * Mode signalling that caller will manage free types in tree decorations.
 495          */
 496         NO_INFERENCE_HOOK {
 497             @Override
 498             public boolean installPostInferenceHook() {
 499                 return false;
 500             }
 501         };
 502 
 503         public boolean updateTreeType() {
 504             return true;
 505         }
 506         public boolean installPostInferenceHook() {
 507             return true;
 508         }
 509     }
 510 
 511 
 512     class ResultInfo {
 513         final KindSelector pkind;
 514         final Type pt;
 515         final CheckContext checkContext;
 516         final CheckMode checkMode;
 517 
 518         ResultInfo(KindSelector pkind, Type pt) {
 519             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 520         }
 521 
 522         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 523             this(pkind, pt, chk.basicHandler, checkMode);
 524         }
 525 
 526         protected ResultInfo(KindSelector pkind,
 527                              Type pt, CheckContext checkContext) {
 528             this(pkind, pt, checkContext, CheckMode.NORMAL);
 529         }
 530 
 531         protected ResultInfo(KindSelector pkind,
 532                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 533             this.pkind = pkind;
 534             this.pt = pt;
 535             this.checkContext = checkContext;
 536             this.checkMode = checkMode;
 537         }
 538 
 539         /**
 540          * Should {@link Attr#attribTree} use the {@code ArgumentAttr} visitor instead of this one?
 541          * @param tree The tree to be type-checked.
 542          * @return true if {@code ArgumentAttr} should be used.
 543          */
 544         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 545 
 546         protected Type check(final DiagnosticPosition pos, final Type found) {
 547             return chk.checkType(pos, found, pt, checkContext);
 548         }
 549 
 550         protected ResultInfo dup(Type newPt) {
 551             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 552         }
 553 
 554         protected ResultInfo dup(CheckContext newContext) {
 555             return new ResultInfo(pkind, pt, newContext, checkMode);
 556         }
 557 
 558         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 559             return new ResultInfo(pkind, newPt, newContext, checkMode);
 560         }
 561 
 562         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 563             return new ResultInfo(pkind, newPt, newContext, newMode);
 564         }
 565 
 566         protected ResultInfo dup(CheckMode newMode) {
 567             return new ResultInfo(pkind, pt, checkContext, newMode);
 568         }
 569 
 570         @Override
 571         public String toString() {
 572             if (pt != null) {
 573                 return pt.toString();
 574             } else {
 575                 return "";
 576             }
 577         }
 578     }
 579 
 580     class MethodAttrInfo extends ResultInfo {
 581         public MethodAttrInfo() {
 582             this(chk.basicHandler);
 583         }
 584 
 585         public MethodAttrInfo(CheckContext checkContext) {
 586             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 587         }
 588 
 589         @Override
 590         protected boolean needsArgumentAttr(JCTree tree) {
 591             return true;
 592         }
 593 
 594         protected ResultInfo dup(Type newPt) {
 595             throw new IllegalStateException();
 596         }
 597 
 598         protected ResultInfo dup(CheckContext newContext) {
 599             return new MethodAttrInfo(newContext);
 600         }
 601 
 602         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 603             throw new IllegalStateException();
 604         }
 605 
 606         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 607             throw new IllegalStateException();
 608         }
 609 
 610         protected ResultInfo dup(CheckMode newMode) {
 611             throw new IllegalStateException();
 612         }
 613     }
 614 
 615     class RecoveryInfo extends ResultInfo {
 616 
 617         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 618             this(deferredAttrContext, Type.recoveryType);
 619         }
 620 
 621         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 622             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 623                 @Override
 624                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 625                     return deferredAttrContext;
 626                 }
 627                 @Override
 628                 public boolean compatible(Type found, Type req, Warner warn) {
 629                     return true;
 630                 }
 631                 @Override
 632                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 633                     boolean needsReport = pt == Type.recoveryType ||
 634                             (details.getDiagnosticPosition() != null &&
 635                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 636                     if (needsReport) {
 637                         chk.basicHandler.report(pos, details);
 638                     }
 639                 }
 640             });
 641         }
 642     }
 643 
 644     final ResultInfo statInfo;
 645     final ResultInfo varAssignmentInfo;
 646     final ResultInfo methodAttrInfo;
 647     final ResultInfo unknownExprInfo;
 648     final ResultInfo unknownTypeInfo;
 649     final ResultInfo unknownTypeExprInfo;
 650     final ResultInfo recoveryInfo;
 651     final MethodType initBlockType;
 652 
 653     Type pt() {
 654         return resultInfo.pt;
 655     }
 656 
 657     KindSelector pkind() {
 658         return resultInfo.pkind;
 659     }
 660 
 661 /* ************************************************************************
 662  * Visitor methods
 663  *************************************************************************/
 664 
 665     /** Visitor argument: the current environment.
 666      */
 667     Env<AttrContext> env;
 668 
 669     /** Visitor argument: the currently expected attribution result.
 670      */
 671     ResultInfo resultInfo;
 672 
 673     /** Visitor result: the computed type.
 674      */
 675     Type result;
 676 
 677     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 678 
 679     /** Visitor method: attribute a tree, catching any completion failure
 680      *  exceptions. Return the tree's type.
 681      *
 682      *  @param tree    The tree to be visited.
 683      *  @param env     The environment visitor argument.
 684      *  @param resultInfo   The result info visitor argument.
 685      */
 686     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 687         Env<AttrContext> prevEnv = this.env;
 688         ResultInfo prevResult = this.resultInfo;
 689         try {
 690             this.env = env;
 691             this.resultInfo = resultInfo;
 692             if (resultInfo.needsArgumentAttr(tree)) {
 693                 result = argumentAttr.attribArg(tree, env);
 694             } else {
 695                 tree.accept(this);
 696             }
 697             matchBindings = matchBindingsComputer.finishBindings(tree,
 698                                                                  matchBindings);
 699             checkBreakTree(tree, env);
 700             return result;
 701         } catch (CompletionFailure ex) {
 702             tree.type = syms.errType;
 703             return chk.completionError(tree.pos(), ex);
 704         } finally {
 705             this.env = prevEnv;
 706             this.resultInfo = prevResult;
 707         }
 708     }
 709 
 710     private void checkBreakTree(JCTree tree, Env<AttrContext> env) {
 711         if (tree == breakTree &&
 712                 resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 713             breakTreeFound(copyEnv(env));
 714         }
 715     }
 716 
 717     protected void breakTreeFound(Env<AttrContext> env) {
 718         throw new BreakAttr(env);
 719     }
 720 
 721     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 722         Env<AttrContext> newEnv =
 723                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 724         if (newEnv.outer != null) {
 725             newEnv.outer = copyEnv(newEnv.outer);
 726         }
 727         return newEnv;
 728     }
 729 
 730     WriteableScope copyScope(WriteableScope sc) {
 731         WriteableScope newScope = WriteableScope.create(sc.owner);
 732         List<Symbol> elemsList = List.nil();
 733         for (Symbol sym : sc.getSymbols()) {
 734             elemsList = elemsList.prepend(sym);
 735         }
 736         for (Symbol s : elemsList) {
 737             newScope.enter(s);
 738         }
 739         return newScope;
 740     }
 741 
 742     /** Derived visitor method: attribute an expression tree.
 743      */
 744     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 745         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 746     }
 747 
 748     /** Derived visitor method: attribute an expression tree with
 749      *  no constraints on the computed type.
 750      */
 751     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 752         return attribTree(tree, env, unknownExprInfo);
 753     }
 754 
 755     /** Derived visitor method: attribute a type tree.
 756      */
 757     public Type attribType(JCTree tree, Env<AttrContext> env) {
 758         Type result = attribType(tree, env, Type.noType);
 759         return result;
 760     }
 761 
 762     /** Derived visitor method: attribute a type tree.
 763      */
 764     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 765         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 766         return result;
 767     }
 768 
 769     /** Derived visitor method: attribute a statement or definition tree.
 770      */
 771     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 772         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 773         Type result = attribTree(tree, env, statInfo);
 774         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 775         attrRecover.doRecovery();
 776         return result;
 777     }
 778 
 779     /** Attribute a list of expressions, returning a list of types.
 780      */
 781     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 782         ListBuffer<Type> ts = new ListBuffer<>();
 783         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 784             ts.append(attribExpr(l.head, env, pt));
 785         return ts.toList();
 786     }
 787 
 788     /** Attribute a list of statements, returning nothing.
 789      */
 790     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 791         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 792             attribStat(l.head, env);
 793     }
 794 
 795     /** Attribute the arguments in a method call, returning the method kind.
 796      */
 797     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 798         KindSelector kind = initialKind;
 799         for (JCExpression arg : trees) {
 800             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 801             if (argtype.hasTag(DEFERRED)) {
 802                 kind = KindSelector.of(KindSelector.POLY, kind);
 803             }
 804             argtypes.append(argtype);
 805         }
 806         return kind;
 807     }
 808 
 809     /** Attribute a type argument list, returning a list of types.
 810      *  Caller is responsible for calling checkRefTypes.
 811      */
 812     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 813         ListBuffer<Type> argtypes = new ListBuffer<>();
 814         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 815             argtypes.append(attribType(l.head, env));
 816         return argtypes.toList();
 817     }
 818 
 819     /** Attribute a type argument list, returning a list of types.
 820      *  Check that all the types are references.
 821      */
 822     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 823         List<Type> types = attribAnyTypes(trees, env);
 824         return chk.checkRefTypes(trees, types);
 825     }
 826 
 827     /**
 828      * Attribute type variables (of generic classes or methods).
 829      * Compound types are attributed later in attribBounds.
 830      * @param typarams the type variables to enter
 831      * @param env      the current environment
 832      */
 833     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 834         for (JCTypeParameter tvar : typarams) {
 835             TypeVar a = (TypeVar)tvar.type;
 836             a.tsym.flags_field |= UNATTRIBUTED;
 837             a.setUpperBound(Type.noType);
 838             if (!tvar.bounds.isEmpty()) {
 839                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 840                 for (JCExpression bound : tvar.bounds.tail)
 841                     bounds = bounds.prepend(attribType(bound, env));
 842                 types.setBounds(a, bounds.reverse());
 843             } else {
 844                 // if no bounds are given, assume a single bound of
 845                 // java.lang.Object.
 846                 types.setBounds(a, List.of(syms.objectType));
 847             }
 848             a.tsym.flags_field &= ~UNATTRIBUTED;
 849         }
 850         if (checkCyclic) {
 851             for (JCTypeParameter tvar : typarams) {
 852                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 853             }
 854         }
 855     }
 856 
 857     /**
 858      * Attribute the type references in a list of annotations.
 859      */
 860     void attribAnnotationTypes(List<JCAnnotation> annotations,
 861                                Env<AttrContext> env) {
 862         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 863             JCAnnotation a = al.head;
 864             attribType(a.annotationType, env);
 865         }
 866     }
 867 
 868     /**
 869      * Attribute a "lazy constant value".
 870      *  @param env         The env for the const value
 871      *  @param variable    The initializer for the const value
 872      *  @param type        The expected type, or null
 873      *  @see VarSymbol#setLazyConstValue
 874      */
 875     public Object attribLazyConstantValue(Env<AttrContext> env,
 876                                       Env<AttrContext> enclosingEnv,
 877                                       JCVariableDecl variable,
 878                                       Type type) {
 879         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 880         try {
 881             doQueueScanTreeAndTypeAnnotateForVarInit(variable, enclosingEnv);
 882             Type itype = attribExpr(variable.init, env, type);
 883             if (variable.isImplicitlyTyped()) {
 884                 //fixup local variable type
 885                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 886             }
 887             if (itype.constValue() != null) {
 888                 return coerce(itype, type).constValue();
 889             } else {
 890                 return null;
 891             }
 892         } finally {
 893             log.useSource(prevSource);
 894         }
 895     }
 896 
 897     /** Attribute type reference in an `extends', `implements', or 'permits' clause.
 898      *  Supertypes of anonymous inner classes are usually already attributed.
 899      *
 900      *  @param tree              The tree making up the type reference.
 901      *  @param env               The environment current at the reference.
 902      *  @param classExpected     true if only a class is expected here.
 903      *  @param interfaceExpected true if only an interface is expected here.
 904      */
 905     Type attribBase(JCTree tree,
 906                     Env<AttrContext> env,
 907                     boolean classExpected,
 908                     boolean interfaceExpected,
 909                     boolean checkExtensible) {
 910         Type t = tree.type != null ?
 911             tree.type :
 912             attribType(tree, env);
 913         try {
 914             return tree.type = checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 915         } catch (CompletionFailure ex) {
 916             chk.completionError(tree.pos(), ex);
 917             return t;
 918         }
 919     }
 920     Type checkBase(Type t,
 921                    JCTree tree,
 922                    Env<AttrContext> env,
 923                    boolean classExpected,
 924                    boolean interfaceExpected,
 925                    boolean checkExtensible) {
 926         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 927                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 928         if (t.tsym.isAnonymous()) {
 929             log.error(pos, Errors.CantInheritFromAnon);
 930             return types.createErrorType(t);
 931         }
 932         if (t.isErroneous())
 933             return t;
 934         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 935             // check that type variable is already visible
 936             if (t.getUpperBound() == null) {
 937                 log.error(pos, Errors.IllegalForwardRef);
 938                 return types.createErrorType(t);
 939             }
 940         } else {
 941             t = chk.checkClassType(pos, t, checkExtensible);
 942         }
 943         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 944             log.error(pos, Errors.IntfExpectedHere);
 945             // return errType is necessary since otherwise there might
 946             // be undetected cycles which cause attribution to loop
 947             return types.createErrorType(t);
 948         } else if (checkExtensible &&
 949                    classExpected &&
 950                    (t.tsym.flags() & INTERFACE) != 0) {
 951             log.error(pos, Errors.NoIntfExpectedHere);
 952             return types.createErrorType(t);
 953         }
 954         if (checkExtensible &&
 955             ((t.tsym.flags() & FINAL) != 0)) {
 956             log.error(pos,
 957                       Errors.CantInheritFromFinal(t.tsym));
 958         }
 959         chk.checkNonCyclic(pos, t);
 960         return t;
 961     }
 962 
 963     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 964         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 965         id.type = env.info.scope.owner.enclClass().type;
 966         id.sym = env.info.scope.owner.enclClass();
 967         return id.type;
 968     }
 969 
 970     public void visitClassDef(JCClassDecl tree) {
 971         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 972                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 973                         argumentAttr.withLocalCacheContext() : null);
 974         boolean ctorProloguePrev = env.info.ctorPrologue;
 975         try {
 976             // Local and anonymous classes have not been entered yet, so we need to
 977             // do it now.
 978             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 979                 enter.classEnter(tree, env);
 980             } else {
 981                 // If this class declaration is part of a class level annotation,
 982                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 983                 // order to simplify later steps and allow for sensible error
 984                 // messages.
 985                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 986                     enter.classEnter(tree, env);
 987             }
 988 
 989             ClassSymbol c = tree.sym;
 990             if (c == null) {
 991                 // exit in case something drastic went wrong during enter.
 992                 result = null;
 993             } else {
 994                 // make sure class has been completed:
 995                 c.complete();
 996 
 997                 // If a class declaration appears in a constructor prologue,
 998                 // that means it's either a local class or an anonymous class.
 999                 // Either way, there is no immediately enclosing instance.
1000                 if (ctorProloguePrev) {
1001                     c.flags_field |= NOOUTERTHIS;
1002                 }
1003                 attribClass(tree.pos(), c);
1004                 result = tree.type = c.type;
1005             }
1006         } finally {
1007             localCacheContext.ifPresent(LocalCacheContext::leave);
1008             env.info.ctorPrologue = ctorProloguePrev;
1009         }
1010     }
1011 
1012     public void visitMethodDef(JCMethodDecl tree) {
1013         MethodSymbol m = tree.sym;
1014         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
1015 
1016         Lint lint = env.info.lint.augment(m);
1017         Lint prevLint = chk.setLint(lint);
1018         boolean ctorProloguePrev = env.info.ctorPrologue;
1019         Assert.check(!env.info.ctorPrologue);
1020         MethodSymbol prevMethod = chk.setMethod(m);
1021         try {
1022             chk.checkDeprecatedAnnotation(tree.pos(), m);
1023 
1024 
1025             // Create a new environment with local scope
1026             // for attributing the method.
1027             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
1028             localEnv.info.lint = lint;
1029 
1030             attribStats(tree.typarams, localEnv);
1031 
1032             // If we override any other methods, check that we do so properly.
1033             // JLS ???
1034             if (m.isStatic()) {
1035                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1036             } else {
1037                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1038             }
1039             chk.checkOverride(env, tree, m);
1040 
1041             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1042                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1043             }
1044 
1045             // Enter all type parameters into the local method scope.
1046             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1047                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1048 
1049             ClassSymbol owner = env.enclClass.sym;
1050             if ((owner.flags() & ANNOTATION) != 0 &&
1051                     (tree.params.nonEmpty() ||
1052                     tree.recvparam != null))
1053                 log.error(tree.params.nonEmpty() ?
1054                         tree.params.head.pos() :
1055                         tree.recvparam.pos(),
1056                         Errors.IntfAnnotationMembersCantHaveParams);
1057 
1058             // Attribute all value parameters.
1059             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1060                 attribStat(l.head, localEnv);
1061             }
1062 
1063             chk.checkVarargsMethodDecl(localEnv, tree);
1064 
1065             // Check that type parameters are well-formed.
1066             chk.validate(tree.typarams, localEnv);
1067 
1068             // Check that result type is well-formed.
1069             if (tree.restype != null && !tree.restype.type.hasTag(VOID)) {
1070                 chk.validate(tree.restype, localEnv);
1071             }
1072             chk.checkRequiresIdentity(tree, env.info.lint);
1073 
1074             // Check that receiver type is well-formed.
1075             if (tree.recvparam != null) {
1076                 // Use a new environment to check the receiver parameter.
1077                 // Otherwise I get "might not have been initialized" errors.
1078                 // Is there a better way?
1079                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1080                 attribType(tree.recvparam, newEnv);
1081                 chk.validate(tree.recvparam, newEnv);
1082             }
1083 
1084             // Is this method a constructor?
1085             boolean isConstructor = TreeInfo.isConstructor(tree);
1086 
1087             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1088                 // lets find if this method is an accessor
1089                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1090                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1091                 if (recordComponent.isPresent()) {
1092                     // the method is a user defined accessor lets check that everything is fine
1093                     if (!tree.sym.isPublic()) {
1094                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1095                     }
1096                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1097                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1098                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1099                     }
1100                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1101                         log.error(tree,
1102                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1103                     }
1104                     if (!tree.typarams.isEmpty()) {
1105                         log.error(tree,
1106                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1107                     }
1108                     if (tree.sym.isStatic()) {
1109                         log.error(tree,
1110                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1111                     }
1112                 }
1113 
1114                 if (isConstructor) {
1115                     // if this a constructor other than the canonical one
1116                     if ((tree.sym.flags_field & RECORD) == 0) {
1117                         if (!TreeInfo.hasConstructorCall(tree, names._this)) {
1118                             log.error(tree, Errors.NonCanonicalConstructorInvokeAnotherConstructor(env.enclClass.sym));
1119                         }
1120                     } else {
1121                         // but if it is the canonical:
1122 
1123                         /* if user generated, then it shouldn't:
1124                          *     - have an accessibility stricter than that of the record type
1125                          *     - explicitly invoke any other constructor
1126                          */
1127                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1128                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1129                                 log.error(tree,
1130                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1131                                             Errors.InvalidCanonicalConstructorInRecord(
1132                                                 Fragments.Canonical,
1133                                                 env.enclClass.sym.name,
1134                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1135                                             ) :
1136                                             Errors.InvalidCanonicalConstructorInRecord(
1137                                                     Fragments.Canonical,
1138                                                     env.enclClass.sym.name,
1139                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1140                                             )
1141                                 );
1142                             }
1143 
1144                             if (TreeInfo.hasAnyConstructorCall(tree)) {
1145                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1146                                         Fragments.Canonical, env.enclClass.sym.name,
1147                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1148                             }
1149                         }
1150 
1151                         // also we want to check that no type variables have been defined
1152                         if (!tree.typarams.isEmpty()) {
1153                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1154                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1155                         }
1156 
1157                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1158                          * record components
1159                          */
1160                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1161                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1162                         for (JCVariableDecl param: tree.params) {
1163                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1164                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1165                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1166                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1167                                         Fragments.Canonical, env.enclClass.sym.name,
1168                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1169                             }
1170                             recordComponents = recordComponents.tail;
1171                             recordFieldTypes = recordFieldTypes.tail;
1172                         }
1173                     }
1174                 }
1175             }
1176 
1177             // annotation method checks
1178             if ((owner.flags() & ANNOTATION) != 0) {
1179                 // annotation method cannot have throws clause
1180                 if (tree.thrown.nonEmpty()) {
1181                     log.error(tree.thrown.head.pos(),
1182                               Errors.ThrowsNotAllowedInIntfAnnotation);
1183                 }
1184                 // annotation method cannot declare type-parameters
1185                 if (tree.typarams.nonEmpty()) {
1186                     log.error(tree.typarams.head.pos(),
1187                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1188                 }
1189                 // validate annotation method's return type (could be an annotation type)
1190                 chk.validateAnnotationType(tree.restype);
1191                 // ensure that annotation method does not clash with members of Object/Annotation
1192                 chk.validateAnnotationMethod(tree.pos(), m);
1193             }
1194 
1195             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1196                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1197 
1198             if (tree.body == null) {
1199                 // Empty bodies are only allowed for
1200                 // abstract, native, or interface methods, or for methods
1201                 // in a retrofit signature class.
1202                 if (tree.defaultValue != null) {
1203                     if ((owner.flags() & ANNOTATION) == 0)
1204                         log.error(tree.pos(),
1205                                   Errors.DefaultAllowedInIntfAnnotationMember);
1206                 }
1207                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1208                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract(tree.sym, owner));
1209             } else {
1210                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1211                     if ((owner.flags() & INTERFACE) != 0) {
1212                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1213                     } else {
1214                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1215                     }
1216                 } else if ((tree.mods.flags & NATIVE) != 0) {
1217                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1218                 }
1219                 // Add an implicit super() call unless an explicit call to
1220                 // super(...) or this(...) is given
1221                 // or we are compiling class java.lang.Object.
1222                 if (isConstructor && owner.type != syms.objectType) {
1223                     if (!TreeInfo.hasAnyConstructorCall(tree)) {
1224                         JCStatement supCall = make.at(tree.body.pos).Exec(make.Apply(List.nil(),
1225                                 make.Ident(names._super), make.Idents(List.nil())));
1226                         tree.body.stats = tree.body.stats.prepend(supCall);
1227                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1228                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1229                             TreeInfo.hasConstructorCall(tree, names._super)) {
1230                         // enum constructors are not allowed to call super
1231                         // directly, so make sure there aren't any super calls
1232                         // in enum constructors, except in the compiler
1233                         // generated one.
1234                         log.error(tree.body.stats.head.pos(),
1235                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1236                     }
1237                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1238                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1239                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1240                         if (!initParamNames.equals(recordComponentNames)) {
1241                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1242                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1243                         }
1244                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1245                             log.error(tree,
1246                                     Errors.InvalidCanonicalConstructorInRecord(
1247                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1248                                             env.enclClass.sym.name,
1249                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1250                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1251                         }
1252                     }
1253                 }
1254 
1255                 // Attribute all type annotations in the body
1256                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m);
1257                 annotate.flush();
1258 
1259                 // Start of constructor prologue (if not in java.lang.Object constructor)
1260                 localEnv.info.ctorPrologue = isConstructor && owner.type != syms.objectType;
1261 
1262                 // Attribute method body.
1263                 attribStat(tree.body, localEnv);
1264             }
1265 
1266             localEnv.info.scope.leave();
1267             result = tree.type = m.type;
1268         } finally {
1269             chk.setLint(prevLint);
1270             chk.setMethod(prevMethod);
1271             env.info.ctorPrologue = ctorProloguePrev;
1272         }
1273     }
1274 
1275     public void visitVarDef(JCVariableDecl tree) {
1276         // Local variables have not been entered yet, so we need to do it now:
1277         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1278             if (tree.sym != null) {
1279                 // parameters have already been entered
1280                 env.info.scope.enter(tree.sym);
1281             } else {
1282                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0 && tree.type == null) {
1283                     if (tree.init == null) {
1284                         //cannot use 'var' without initializer
1285                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1286                         tree.type = syms.errType;
1287                     } else {
1288                         Fragment msg = canInferLocalVarType(tree);
1289                         if (msg != null) {
1290                             //cannot use 'var' with initializer which require an explicit target
1291                             //(e.g. lambda, method reference, array initializer).
1292                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1293                             tree.type = syms.errType;
1294                         }
1295                     }
1296                 }
1297                 try {
1298                     annotate.blockAnnotations();
1299                     memberEnter.memberEnter(tree, env);
1300                     typeAnnotations.organizeTypeAnnotationsSignaturesForLocalVarType(env, tree);
1301                 } finally {
1302                     annotate.unblockAnnotations();
1303                 }
1304             }
1305         } else {
1306             doQueueScanTreeAndTypeAnnotateForVarInit(tree, env);
1307         }
1308 
1309         VarSymbol v = tree.sym;
1310         Lint lint = env.info.lint.augment(v);
1311         Lint prevLint = chk.setLint(lint);
1312 
1313         // Check that the variable's declared type is well-formed.
1314         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1315                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1316                 (tree.sym.flags() & PARAMETER) != 0;
1317         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1318 
1319         try {
1320             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1321             chk.checkDeprecatedAnnotation(tree.pos(), v);
1322 
1323             if (tree.init != null) {
1324                 if ((v.flags_field & FINAL) == 0 ||
1325                     !memberEnter.needsLazyConstValue(tree.init)) {
1326                     // Not a compile-time constant
1327                     // Attribute initializer in a new environment
1328                     // with the declared variable as owner.
1329                     // Check that initializer conforms to variable's declared type.
1330                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
1331                     initEnv.info.lint = lint;
1332                     // In order to catch self-references, we set the variable's
1333                     // declaration position to maximal possible value, effectively
1334                     // marking the variable as undefined.
1335                     initEnv.info.enclVar = v;
1336                     attribExpr(tree.init, initEnv, v.type);
1337                     if (tree.isImplicitlyTyped()) {
1338                         //fixup local variable type
1339                         v.type = chk.checkLocalVarType(tree, tree.init.type, tree.name);
1340                     }
1341                 }
1342                 if (tree.isImplicitlyTyped()) {
1343                     setupImplicitlyTypedVariable(tree, v.type);
1344                 }
1345             }
1346             result = tree.type = v.type;
1347             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
1348                 if (isNonArgsMethodInObject(v.name)) {
1349                     log.error(tree, Errors.IllegalRecordComponentName(v));
1350                 }
1351             }
1352             chk.checkRequiresIdentity(tree, env.info.lint);
1353         }
1354         finally {
1355             chk.setLint(prevLint);
1356         }
1357     }
1358 
1359     private void doQueueScanTreeAndTypeAnnotateForVarInit(JCVariableDecl tree, Env<AttrContext> env) {
1360         if (tree.init != null &&
1361             (tree.sym.flags_field & Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED) == 0 &&
1362             env.info.scope.owner.kind != MTH && env.info.scope.owner.kind != VAR) {
1363             tree.sym.flags_field |= Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED;
1364             // Field initializer expression need to be entered.
1365             annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym);
1366             annotate.flush();
1367         }
1368     }
1369 
1370     private boolean isNonArgsMethodInObject(Name name) {
1371         for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
1372             if (s.type.getParameterTypes().isEmpty()) {
1373                 return true;
1374             }
1375         }
1376         return false;
1377     }
1378 
1379     Fragment canInferLocalVarType(JCVariableDecl tree) {
1380         LocalInitScanner lis = new LocalInitScanner();
1381         lis.scan(tree.init);
1382         return lis.badInferenceMsg;
1383     }
1384 
1385     static class LocalInitScanner extends TreeScanner {
1386         Fragment badInferenceMsg = null;
1387         boolean needsTarget = true;
1388 
1389         @Override
1390         public void visitNewArray(JCNewArray tree) {
1391             if (tree.elemtype == null && needsTarget) {
1392                 badInferenceMsg = Fragments.LocalArrayMissingTarget;
1393             }
1394         }
1395 
1396         @Override
1397         public void visitLambda(JCLambda tree) {
1398             if (needsTarget) {
1399                 badInferenceMsg = Fragments.LocalLambdaMissingTarget;
1400             }
1401         }
1402 
1403         @Override
1404         public void visitTypeCast(JCTypeCast tree) {
1405             boolean prevNeedsTarget = needsTarget;
1406             try {
1407                 needsTarget = false;
1408                 super.visitTypeCast(tree);
1409             } finally {
1410                 needsTarget = prevNeedsTarget;
1411             }
1412         }
1413 
1414         @Override
1415         public void visitReference(JCMemberReference tree) {
1416             if (needsTarget) {
1417                 badInferenceMsg = Fragments.LocalMrefMissingTarget;
1418             }
1419         }
1420 
1421         @Override
1422         public void visitNewClass(JCNewClass tree) {
1423             boolean prevNeedsTarget = needsTarget;
1424             try {
1425                 needsTarget = false;
1426                 super.visitNewClass(tree);
1427             } finally {
1428                 needsTarget = prevNeedsTarget;
1429             }
1430         }
1431 
1432         @Override
1433         public void visitApply(JCMethodInvocation tree) {
1434             boolean prevNeedsTarget = needsTarget;
1435             try {
1436                 needsTarget = false;
1437                 super.visitApply(tree);
1438             } finally {
1439                 needsTarget = prevNeedsTarget;
1440             }
1441         }
1442     }
1443 
1444     public void visitSkip(JCSkip tree) {
1445         result = null;
1446     }
1447 
1448     public void visitBlock(JCBlock tree) {
1449         if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
1450             // Block is a static or instance initializer;
1451             // let the owner of the environment be a freshly
1452             // created BLOCK-method.
1453             Symbol fakeOwner =
1454                 new MethodSymbol(tree.flags | BLOCK |
1455                     env.info.scope.owner.flags() & STRICTFP, names.empty, initBlockType,
1456                     env.info.scope.owner);
1457             final Env<AttrContext> localEnv =
1458                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
1459 
1460             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
1461             // Attribute all type annotations in the block
1462             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner);
1463             annotate.flush();
1464             attribStats(tree.stats, localEnv);
1465 
1466             {
1467                 // Store init and clinit type annotations with the ClassSymbol
1468                 // to allow output in Gen.normalizeDefs.
1469                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1470                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1471                 if ((tree.flags & STATIC) != 0) {
1472                     cs.appendClassInitTypeAttributes(tas);
1473                 } else {
1474                     cs.appendInitTypeAttributes(tas);
1475                 }
1476             }
1477         } else {
1478             // Create a new local environment with a local scope.
1479             Env<AttrContext> localEnv =
1480                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1481             try {
1482                 attribStats(tree.stats, localEnv);
1483             } finally {
1484                 localEnv.info.scope.leave();
1485             }
1486         }
1487         result = null;
1488     }
1489 
1490     public void visitDoLoop(JCDoWhileLoop tree) {
1491         attribStat(tree.body, env.dup(tree));
1492         attribExpr(tree.cond, env, syms.booleanType);
1493         handleLoopConditionBindings(matchBindings, tree, tree.body);
1494         result = null;
1495     }
1496 
1497     public void visitWhileLoop(JCWhileLoop tree) {
1498         attribExpr(tree.cond, env, syms.booleanType);
1499         MatchBindings condBindings = matchBindings;
1500         // include condition's bindings when true in the body:
1501         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1502         try {
1503             attribStat(tree.body, whileEnv.dup(tree));
1504         } finally {
1505             whileEnv.info.scope.leave();
1506         }
1507         handleLoopConditionBindings(condBindings, tree, tree.body);
1508         result = null;
1509     }
1510 
1511     public void visitForLoop(JCForLoop tree) {
1512         Env<AttrContext> loopEnv =
1513             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1514         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1515         try {
1516             attribStats(tree.init, loopEnv);
1517             if (tree.cond != null) {
1518                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1519                 // include condition's bindings when true in the body and step:
1520                 condBindings = matchBindings;
1521             }
1522             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1523             try {
1524                 bodyEnv.tree = tree; // before, we were not in loop!
1525                 attribStats(tree.step, bodyEnv);
1526                 attribStat(tree.body, bodyEnv);
1527             } finally {
1528                 bodyEnv.info.scope.leave();
1529             }
1530             result = null;
1531         }
1532         finally {
1533             loopEnv.info.scope.leave();
1534         }
1535         handleLoopConditionBindings(condBindings, tree, tree.body);
1536     }
1537 
1538     /**
1539      * Include condition's bindings when false after the loop, if cannot get out of the loop
1540      */
1541     private void handleLoopConditionBindings(MatchBindings condBindings,
1542                                              JCStatement loop,
1543                                              JCStatement loopBody) {
1544         if (condBindings.bindingsWhenFalse.nonEmpty() &&
1545             !breaksTo(env, loop, loopBody)) {
1546             addBindings2Scope(loop, condBindings.bindingsWhenFalse);
1547         }
1548     }
1549 
1550     private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
1551         preFlow(body);
1552         return flow.breaksToTree(env, loop, body, make);
1553     }
1554 
1555     /**
1556      * Add given bindings to the current scope, unless there's a break to
1557      * an immediately enclosing labeled statement.
1558      */
1559     private void addBindings2Scope(JCStatement introducingStatement,
1560                                    List<BindingSymbol> bindings) {
1561         if (bindings.isEmpty()) {
1562             return ;
1563         }
1564 
1565         var searchEnv = env;
1566         while (searchEnv.tree instanceof JCLabeledStatement labeled &&
1567                labeled.body == introducingStatement) {
1568             if (breaksTo(env, labeled, labeled.body)) {
1569                 //breaking to an immediately enclosing labeled statement
1570                 return ;
1571             }
1572             searchEnv = searchEnv.next;
1573             introducingStatement = labeled;
1574         }
1575 
1576         //include condition's body when false after the while, if cannot get out of the loop
1577         bindings.forEach(env.info.scope::enter);
1578         bindings.forEach(BindingSymbol::preserveBinding);
1579     }
1580 
1581     public void visitForeachLoop(JCEnhancedForLoop tree) {
1582         Env<AttrContext> loopEnv =
1583             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1584         try {
1585             //the Formal Parameter of a for-each loop is not in the scope when
1586             //attributing the for-each expression; we mimic this by attributing
1587             //the for-each expression first (against original scope).
1588             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1589             chk.checkNonVoid(tree.pos(), exprType);
1590             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1591             if (elemtype == null) {
1592                 // or perhaps expr implements Iterable<T>?
1593                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1594                 if (base == null) {
1595                     log.error(tree.expr.pos(),
1596                               Errors.ForeachNotApplicableToType(exprType,
1597                                                                 Fragments.TypeReqArrayOrIterable));
1598                     elemtype = types.createErrorType(exprType);
1599                 } else {
1600                     List<Type> iterableParams = base.allparams();
1601                     elemtype = iterableParams.isEmpty()
1602                         ? syms.objectType
1603                         : types.wildUpperBound(iterableParams.head);
1604 
1605                     // Check the return type of the method iterator().
1606                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1607                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1608                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1609                     if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
1610                         log.error(tree.pos(),
1611                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1612                     }
1613                 }
1614             }
1615             if (tree.var.isImplicitlyTyped()) {
1616                 Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
1617                 tree.var.type = inferredType;
1618                 setupImplicitlyTypedVariable(tree.var, inferredType);
1619             }
1620             attribStat(tree.var, loopEnv);
1621             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1622             loopEnv.tree = tree; // before, we were not in loop!
1623             attribStat(tree.body, loopEnv);
1624             result = null;
1625         }
1626         finally {
1627             loopEnv.info.scope.leave();
1628         }
1629     }
1630 
1631     public void visitLabelled(JCLabeledStatement tree) {
1632         // Check that label is not used in an enclosing statement
1633         Env<AttrContext> env1 = env;
1634         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1635             if (env1.tree.hasTag(LABELLED) &&
1636                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1637                 log.error(tree.pos(),
1638                           Errors.LabelAlreadyInUse(tree.label));
1639                 break;
1640             }
1641             env1 = env1.next;
1642         }
1643 
1644         attribStat(tree.body, env.dup(tree));
1645         result = null;
1646     }
1647 
1648     public void visitSwitch(JCSwitch tree) {
1649         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1650             attribStats(c.stats, caseEnv);
1651         });
1652         result = null;
1653     }
1654 
1655     public void visitSwitchExpression(JCSwitchExpression tree) {
1656         boolean wrongContext = false;
1657 
1658         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
1659                 PolyKind.STANDALONE : PolyKind.POLY;
1660 
1661         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
1662             //this means we are returning a poly conditional from void-compatible lambda expression
1663             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
1664             resultInfo = recoveryInfo;
1665             wrongContext = true;
1666         }
1667 
1668         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
1669                 unknownExprInfo :
1670                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
1671 
1672         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
1673         ListBuffer<Type> caseTypes = new ListBuffer<>();
1674 
1675         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1676             caseEnv.info.yieldResult = condInfo;
1677             attribStats(c.stats, caseEnv);
1678             new TreeScanner() {
1679                 @Override
1680                 public void visitYield(JCYield brk) {
1681                     if (brk.target == tree) {
1682                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
1683                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
1684                     }
1685                     super.visitYield(brk);
1686                 }
1687 
1688                 @Override public void visitClassDef(JCClassDecl tree) {}
1689                 @Override public void visitLambda(JCLambda tree) {}
1690             }.scan(c.stats);
1691         });
1692 
1693         if (tree.cases.isEmpty()) {
1694             log.error(tree.pos(),
1695                       Errors.SwitchExpressionEmpty);
1696         } else if (caseTypes.isEmpty()) {
1697             log.error(tree.pos(),
1698                       Errors.SwitchExpressionNoResultExpressions);
1699         }
1700 
1701         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
1702 
1703         result = tree.type = wrongContext? types.createErrorType(pt()) : check(tree, owntype, KindSelector.VAL, resultInfo);
1704     }
1705     //where:
1706         CheckContext switchExpressionContext(CheckContext checkContext) {
1707             return new Check.NestedCheckContext(checkContext) {
1708                 //this will use enclosing check context to check compatibility of
1709                 //subexpression against target type; if we are in a method check context,
1710                 //depending on whether boxing is allowed, we could have incompatibilities
1711                 @Override
1712                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1713                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
1714                 }
1715             };
1716         }
1717 
1718     private void handleSwitch(JCTree switchTree,
1719                               JCExpression selector,
1720                               List<JCCase> cases,
1721                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
1722         Type seltype = attribExpr(selector, env);
1723         Type seltypeUnboxed = types.unboxedTypeOrType(seltype);
1724 
1725         Env<AttrContext> switchEnv =
1726             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
1727 
1728         try {
1729             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
1730             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
1731             boolean booleanSwitch = types.isSameType(seltypeUnboxed, syms.booleanType);
1732             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
1733             boolean intSwitch = types.isAssignable(seltype, syms.intType);
1734             boolean patternSwitch;
1735             if (seltype.isPrimitive() && !intSwitch) {
1736                 preview.checkSourceLevel(selector.pos(), Feature.PRIMITIVE_PATTERNS);
1737                 patternSwitch = true;
1738             }
1739             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
1740                 !intSwitch) {
1741                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
1742                 patternSwitch = true;
1743             } else {
1744                 patternSwitch = cases.stream()
1745                                      .flatMap(c -> c.labels.stream())
1746                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
1747                                                     TreeInfo.isNullCaseLabel(l));
1748             }
1749 
1750             // Attribute all cases and
1751             // check that there are no duplicate case labels or default clauses.
1752             Set<Object> constants = new HashSet<>(); // The set of case constants.
1753             boolean hasDefault = false;           // Is there a default label?
1754             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
1755             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
1756             boolean hasNullPattern = false;       // Is there a null pattern?
1757             CaseTree.CaseKind caseKind = null;
1758             boolean wasError = false;
1759             JCCaseLabel unconditionalCaseLabel = null;
1760             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
1761                 JCCase c = l.head;
1762                 if (caseKind == null) {
1763                     caseKind = c.caseKind;
1764                 } else if (caseKind != c.caseKind && !wasError) {
1765                     log.error(c.pos(),
1766                               Errors.SwitchMixingCaseTypes);
1767                     wasError = true;
1768                 }
1769                 MatchBindings currentBindings = null;
1770                 MatchBindings guardBindings = null;
1771                 for (List<JCCaseLabel> labels = c.labels; labels.nonEmpty(); labels = labels.tail) {
1772                     JCCaseLabel label = labels.head;
1773                     if (label instanceof JCConstantCaseLabel constLabel) {
1774                         JCExpression expr = constLabel.expr;
1775                         if (TreeInfo.isNull(expr)) {
1776                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
1777                             if (hasNullPattern) {
1778                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1779                             }
1780                             hasNullPattern = true;
1781                             attribExpr(expr, switchEnv, seltype);
1782                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
1783                         } else if (enumSwitch) {
1784                             Symbol sym = enumConstant(expr, seltype);
1785                             if (sym == null) {
1786                                 if (allowPatternSwitch) {
1787                                     attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1788                                     Symbol enumSym = TreeInfo.symbol(expr);
1789                                     if (enumSym == null || !enumSym.isEnum() || enumSym.kind != VAR) {
1790                                         log.error(expr.pos(), Errors.EnumLabelMustBeEnumConstant);
1791                                     } else if (!constants.add(enumSym)) {
1792                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1793                                     }
1794                                 } else {
1795                                     log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
1796                                 }
1797                             } else if (!constants.add(sym)) {
1798                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1799                             }
1800                         } else if (errorEnumSwitch) {
1801                             //error recovery: the selector is erroneous, and all the case labels
1802                             //are identifiers. This could be an enum switch - don't report resolve
1803                             //error for the case label:
1804                             var prevResolveHelper = rs.basicLogResolveHelper;
1805                             try {
1806                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
1807                                 attribExpr(expr, switchEnv, seltype);
1808                             } finally {
1809                                 rs.basicLogResolveHelper = prevResolveHelper;
1810                             }
1811                         } else {
1812                             Type pattype = attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1813                             if (!pattype.hasTag(ERROR)) {
1814                                 if (pattype.constValue() == null) {
1815                                     Symbol s = TreeInfo.symbol(expr);
1816                                     if (s != null && s.kind == TYP) {
1817                                         log.error(expr.pos(),
1818                                                   Errors.PatternExpected);
1819                                     } else if (s == null || !s.isEnum()) {
1820                                         log.error(expr.pos(),
1821                                                   (stringSwitch ? Errors.StringConstReq
1822                                                                 : intSwitch ? Errors.ConstExprReq
1823                                                                             : Errors.PatternOrEnumReq));
1824                                     } else if (!constants.add(s)) {
1825                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1826                                     }
1827                                 }
1828                                 else {
1829                                     boolean isLongFloatDoubleOrBooleanConstant =
1830                                             pattype.getTag().isInSuperClassesOf(LONG) || pattype.getTag().equals(BOOLEAN);
1831                                     if (isLongFloatDoubleOrBooleanConstant) {
1832                                         preview.checkSourceLevel(label.pos(), Feature.PRIMITIVE_PATTERNS);
1833                                     }
1834                                     if (!stringSwitch && !intSwitch && !(isLongFloatDoubleOrBooleanConstant && types.isSameType(seltypeUnboxed, pattype))) {
1835                                         log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
1836                                     } else if (!constants.add(pattype.constValue())) {
1837                                         log.error(c.pos(), Errors.DuplicateCaseLabel);
1838                                     }
1839                                 }
1840                             }
1841                         }
1842                     } else if (label instanceof JCDefaultCaseLabel def) {
1843                         if (hasDefault) {
1844                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
1845                         } else if (hasUnconditionalPattern) {
1846                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
1847                         }  else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1848                             log.error(label.pos(), Errors.DefaultAndBothBooleanValues);
1849                         }
1850                         hasDefault = true;
1851                         matchBindings = MatchBindingsComputer.EMPTY;
1852                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
1853                         //pattern
1854                         JCPattern pat = patternlabel.pat;
1855                         attribExpr(pat, switchEnv, seltype);
1856                         Type primaryType = TreeInfo.primaryPatternType(pat);
1857 
1858                         if (primaryType.isPrimitive()) {
1859                             preview.checkSourceLevel(pat.pos(), Feature.PRIMITIVE_PATTERNS);
1860                         } else if (!primaryType.hasTag(TYPEVAR)) {
1861                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
1862                         }
1863                         checkCastablePattern(pat.pos(), seltype, primaryType);
1864                         Type patternType = types.erasure(primaryType);
1865                         JCExpression guard = c.guard;
1866                         if (guardBindings == null && guard != null) {
1867                             MatchBindings afterPattern = matchBindings;
1868                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
1869                             try {
1870                                 attribExpr(guard, bodyEnv, syms.booleanType);
1871                             } finally {
1872                                 bodyEnv.info.scope.leave();
1873                             }
1874 
1875                             guardBindings = matchBindings;
1876                             matchBindings = afterPattern;
1877 
1878                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
1879                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
1880                             }
1881                         }
1882                         boolean unguarded = TreeInfo.unguardedCase(c) && !pat.hasTag(RECORDPATTERN);
1883                         boolean unconditional =
1884                                 unguarded &&
1885                                 !patternType.isErroneous() &&
1886                                 types.isUnconditionallyExactTypeBased(seltype, patternType);
1887                         if (unconditional) {
1888                             if (hasUnconditionalPattern) {
1889                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
1890                             } else if (hasDefault) {
1891                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
1892                             } else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1893                                 log.error(pat.pos(), Errors.UnconditionalPatternAndBothBooleanValues);
1894                             }
1895                             hasUnconditionalPattern = true;
1896                             unconditionalCaseLabel = label;
1897                         }
1898                         lastPatternErroneous = patternType.isErroneous();
1899                     } else {
1900                         Assert.error();
1901                     }
1902                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
1903                 }
1904 
1905                 if (guardBindings != null) {
1906                     currentBindings = matchBindingsComputer.caseGuard(c, currentBindings, guardBindings);
1907                 }
1908 
1909                 Env<AttrContext> caseEnv =
1910                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
1911                 try {
1912                     attribCase.accept(c, caseEnv);
1913                 } finally {
1914                     caseEnv.info.scope.leave();
1915                 }
1916                 addVars(c.stats, switchEnv.info.scope);
1917 
1918                 preFlow(c);
1919                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
1920             }
1921             if (patternSwitch) {
1922                 chk.checkSwitchCaseStructure(cases);
1923                 chk.checkSwitchCaseLabelDominated(unconditionalCaseLabel, cases);
1924             }
1925             if (switchTree.hasTag(SWITCH)) {
1926                 ((JCSwitch) switchTree).hasUnconditionalPattern =
1927                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1928                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
1929             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
1930                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
1931                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1932                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
1933             } else {
1934                 Assert.error(switchTree.getTag().name());
1935             }
1936         } finally {
1937             switchEnv.info.scope.leave();
1938         }
1939     }
1940     // where
1941         private ResultInfo caseLabelResultInfo(Type seltype) {
1942             return new ResultInfo(KindSelector.VAL_TYP,
1943                                   !seltype.hasTag(ERROR) ? seltype
1944                                                          : Type.noType);
1945         }
1946         /** Add any variables defined in stats to the switch scope. */
1947         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
1948             for (;stats.nonEmpty(); stats = stats.tail) {
1949                 JCTree stat = stats.head;
1950                 if (stat.hasTag(VARDEF))
1951                     switchScope.enter(((JCVariableDecl) stat).sym);
1952             }
1953         }
1954     // where
1955     /** Return the selected enumeration constant symbol, or null. */
1956     private Symbol enumConstant(JCTree tree, Type enumType) {
1957         if (tree.hasTag(IDENT)) {
1958             JCIdent ident = (JCIdent)tree;
1959             Name name = ident.name;
1960             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
1961                 if (sym.kind == VAR) {
1962                     Symbol s = ident.sym = sym;
1963                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1964                     ident.type = s.type;
1965                     return ((s.flags_field & Flags.ENUM) == 0)
1966                         ? null : s;
1967                 }
1968             }
1969         }
1970         return null;
1971     }
1972 
1973     public void visitSynchronized(JCSynchronized tree) {
1974         chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
1975         if (tree.lock.type != null && tree.lock.type.isValueBased()) {
1976             log.warning(tree.pos(), LintWarnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
1977         }
1978         attribStat(tree.body, env);
1979         result = null;
1980     }
1981 
1982     public void visitTry(JCTry tree) {
1983         // Create a new local environment with a local
1984         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1985         try {
1986             boolean isTryWithResource = tree.resources.nonEmpty();
1987             // Create a nested environment for attributing the try block if needed
1988             Env<AttrContext> tryEnv = isTryWithResource ?
1989                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1990                 localEnv;
1991             try {
1992                 // Attribute resource declarations
1993                 for (JCTree resource : tree.resources) {
1994                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
1995                         @Override
1996                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
1997                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
1998                         }
1999                     };
2000                     ResultInfo twrResult =
2001                         new ResultInfo(KindSelector.VAR,
2002                                        syms.autoCloseableType,
2003                                        twrContext);
2004                     if (resource.hasTag(VARDEF)) {
2005                         attribStat(resource, tryEnv);
2006                         twrResult.check(resource, resource.type);
2007 
2008                         //check that resource type cannot throw InterruptedException
2009                         checkAutoCloseable(localEnv, resource, true);
2010 
2011                         VarSymbol var = ((JCVariableDecl) resource).sym;
2012 
2013                         var.flags_field |= Flags.FINAL;
2014                         var.setData(ElementKind.RESOURCE_VARIABLE);
2015                     } else {
2016                         attribTree(resource, tryEnv, twrResult);
2017                     }
2018                 }
2019                 // Attribute body
2020                 attribStat(tree.body, tryEnv);
2021             } finally {
2022                 if (isTryWithResource)
2023                     tryEnv.info.scope.leave();
2024             }
2025 
2026             // Attribute catch clauses
2027             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
2028                 JCCatch c = l.head;
2029                 Env<AttrContext> catchEnv =
2030                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
2031                 try {
2032                     Type ctype = attribStat(c.param, catchEnv);
2033                     if (TreeInfo.isMultiCatch(c)) {
2034                         //multi-catch parameter is implicitly marked as final
2035                         c.param.sym.flags_field |= FINAL | UNION;
2036                     }
2037                     if (c.param.sym.kind == VAR) {
2038                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
2039                     }
2040                     chk.checkType(c.param.vartype.pos(),
2041                                   chk.checkClassType(c.param.vartype.pos(), ctype),
2042                                   syms.throwableType);
2043                     attribStat(c.body, catchEnv);
2044                 } finally {
2045                     catchEnv.info.scope.leave();
2046                 }
2047             }
2048 
2049             // Attribute finalizer
2050             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
2051             result = null;
2052         }
2053         finally {
2054             localEnv.info.scope.leave();
2055         }
2056     }
2057 
2058     void checkAutoCloseable(Env<AttrContext> env, JCTree tree, boolean useSite) {
2059         DiagnosticPosition pos = tree.pos();
2060         Type resource = tree.type;
2061         if (!resource.isErroneous() &&
2062             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
2063             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
2064             Symbol close = syms.noSymbol;
2065             Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
2066             try {
2067                 close = rs.resolveQualifiedMethod(pos,
2068                         env,
2069                         types.skipTypeVars(resource, false),
2070                         names.close,
2071                         List.nil(),
2072                         List.nil());
2073             }
2074             finally {
2075                 log.popDiagnosticHandler(discardHandler);
2076             }
2077             if (close.kind == MTH &&
2078                     (useSite || close.owner != syms.autoCloseableType.tsym) &&
2079                     ((MethodSymbol)close).binaryOverrides(syms.autoCloseableClose, resource.tsym, types) &&
2080                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes())) {
2081                 if (!useSite && close.owner == resource.tsym) {
2082                     log.warning(TreeInfo.diagnosticPositionFor(close, tree),
2083                         LintWarnings.TryResourceCanThrowInterruptedExc(resource));
2084                 } else {
2085                     log.warning(pos, LintWarnings.TryResourceThrowsInterruptedExc(resource));
2086                 }
2087             }
2088         }
2089     }
2090 
2091     public void visitConditional(JCConditional tree) {
2092         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2093         MatchBindings condBindings = matchBindings;
2094 
2095         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2096                 isBooleanOrNumeric(env, tree)) ?
2097                 PolyKind.STANDALONE : PolyKind.POLY;
2098 
2099         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2100             //this means we are returning a poly conditional from void-compatible lambda expression
2101             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2102             result = tree.type = types.createErrorType(resultInfo.pt);
2103             return;
2104         }
2105 
2106         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2107                 unknownExprInfo :
2108                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2109 
2110 
2111         // x ? y : z
2112         // include x's bindings when true in y
2113         // include x's bindings when false in z
2114 
2115         Type truetype;
2116         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2117         try {
2118             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2119         } finally {
2120             trueEnv.info.scope.leave();
2121         }
2122 
2123         MatchBindings trueBindings = matchBindings;
2124 
2125         Type falsetype;
2126         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2127         try {
2128             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2129         } finally {
2130             falseEnv.info.scope.leave();
2131         }
2132 
2133         MatchBindings falseBindings = matchBindings;
2134 
2135         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2136                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2137                          List.of(truetype, falsetype)) : pt();
2138         if (condtype.constValue() != null &&
2139                 truetype.constValue() != null &&
2140                 falsetype.constValue() != null &&
2141                 !owntype.hasTag(NONE)) {
2142             //constant folding
2143             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2144         }
2145         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2146         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2147     }
2148     //where
2149         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2150             switch (tree.getTag()) {
2151                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2152                               ((JCLiteral)tree).typetag == BOOLEAN ||
2153                               ((JCLiteral)tree).typetag == BOT;
2154                 case LAMBDA: case REFERENCE: return false;
2155                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2156                 case CONDEXPR:
2157                     JCConditional condTree = (JCConditional)tree;
2158                     return isBooleanOrNumeric(env, condTree.truepart) &&
2159                             isBooleanOrNumeric(env, condTree.falsepart);
2160                 case APPLY:
2161                     JCMethodInvocation speculativeMethodTree =
2162                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2163                                     tree, env, unknownExprInfo,
2164                                     argumentAttr.withLocalCacheContext());
2165                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2166                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2167                             env.enclClass.type :
2168                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2169                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2170                     return primitiveOrBoxed(owntype);
2171                 case NEWCLASS:
2172                     JCExpression className =
2173                             removeClassParams.translate(((JCNewClass)tree).clazz);
2174                     JCExpression speculativeNewClassTree =
2175                             (JCExpression)deferredAttr.attribSpeculative(
2176                                     className, env, unknownTypeInfo,
2177                                     argumentAttr.withLocalCacheContext());
2178                     return primitiveOrBoxed(speculativeNewClassTree.type);
2179                 default:
2180                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2181                             argumentAttr.withLocalCacheContext()).type;
2182                     return primitiveOrBoxed(speculativeType);
2183             }
2184         }
2185         //where
2186             boolean primitiveOrBoxed(Type t) {
2187                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2188             }
2189 
2190             TreeTranslator removeClassParams = new TreeTranslator() {
2191                 @Override
2192                 public void visitTypeApply(JCTypeApply tree) {
2193                     result = translate(tree.clazz);
2194                 }
2195             };
2196 
2197         CheckContext conditionalContext(CheckContext checkContext) {
2198             return new Check.NestedCheckContext(checkContext) {
2199                 //this will use enclosing check context to check compatibility of
2200                 //subexpression against target type; if we are in a method check context,
2201                 //depending on whether boxing is allowed, we could have incompatibilities
2202                 @Override
2203                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2204                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2205                 }
2206             };
2207         }
2208 
2209         /** Compute the type of a conditional expression, after
2210          *  checking that it exists.  See JLS 15.25. Does not take into
2211          *  account the special case where condition and both arms
2212          *  are constants.
2213          *
2214          *  @param pos      The source position to be used for error
2215          *                  diagnostics.
2216          *  @param thentype The type of the expression's then-part.
2217          *  @param elsetype The type of the expression's else-part.
2218          */
2219         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2220             if (condTypes.isEmpty()) {
2221                 return syms.objectType; //TODO: how to handle?
2222             }
2223             Type first = condTypes.head;
2224             // If same type, that is the result
2225             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2226                 return first.baseType();
2227 
2228             List<Type> unboxedTypes = condTypes.stream()
2229                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2230                                                .collect(List.collector());
2231 
2232             // Otherwise, if both arms can be converted to a numeric
2233             // type, return the least numeric type that fits both arms
2234             // (i.e. return larger of the two, or return int if one
2235             // arm is short, the other is char).
2236             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2237                 // If one arm has an integer subrange type (i.e., byte,
2238                 // short, or char), and the other is an integer constant
2239                 // that fits into the subrange, return the subrange type.
2240                 for (Type type : unboxedTypes) {
2241                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2242                         continue;
2243                     }
2244                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2245                         return type.baseType();
2246                 }
2247 
2248                 for (TypeTag tag : primitiveTags) {
2249                     Type candidate = syms.typeOfTag[tag.ordinal()];
2250                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2251                         return candidate;
2252                     }
2253                 }
2254             }
2255 
2256             // Those were all the cases that could result in a primitive
2257             condTypes = condTypes.stream()
2258                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
2259                                  .collect(List.collector());
2260 
2261             for (Type type : condTypes) {
2262                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2263                     return type.baseType();
2264             }
2265 
2266             Iterator<DiagnosticPosition> posIt = positions.iterator();
2267 
2268             condTypes = condTypes.stream()
2269                                  .map(t -> chk.checkNonVoid(posIt.next(), t))
2270                                  .collect(List.collector());
2271 
2272             // both are known to be reference types.  The result is
2273             // lub(thentype,elsetype). This cannot fail, as it will
2274             // always be possible to infer "Object" if nothing better.
2275             return types.lub(condTypes.stream()
2276                         .map(t -> t.baseType())
2277                         .filter(t -> !t.hasTag(BOT))
2278                         .collect(List.collector()));
2279         }
2280 
2281     static final TypeTag[] primitiveTags = new TypeTag[]{
2282         BYTE,
2283         CHAR,
2284         SHORT,
2285         INT,
2286         LONG,
2287         FLOAT,
2288         DOUBLE,
2289         BOOLEAN,
2290     };
2291 
2292     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2293         return bindingEnv(env, env.tree, bindings);
2294     }
2295 
2296     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2297         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2298         bindings.forEach(env1.info.scope::enter);
2299         return env1;
2300     }
2301 
2302     public void visitIf(JCIf tree) {
2303         attribExpr(tree.cond, env, syms.booleanType);
2304 
2305         // if (x) { y } [ else z ]
2306         // include x's bindings when true in y
2307         // include x's bindings when false in z
2308 
2309         MatchBindings condBindings = matchBindings;
2310         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2311 
2312         try {
2313             attribStat(tree.thenpart, thenEnv);
2314         } finally {
2315             thenEnv.info.scope.leave();
2316         }
2317 
2318         preFlow(tree.thenpart);
2319         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2320         boolean aliveAfterElse;
2321 
2322         if (tree.elsepart != null) {
2323             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2324             try {
2325                 attribStat(tree.elsepart, elseEnv);
2326             } finally {
2327                 elseEnv.info.scope.leave();
2328             }
2329             preFlow(tree.elsepart);
2330             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2331         } else {
2332             aliveAfterElse = true;
2333         }
2334 
2335         chk.checkEmptyIf(tree);
2336 
2337         List<BindingSymbol> afterIfBindings = List.nil();
2338 
2339         if (aliveAfterThen && !aliveAfterElse) {
2340             afterIfBindings = condBindings.bindingsWhenTrue;
2341         } else if (aliveAfterElse && !aliveAfterThen) {
2342             afterIfBindings = condBindings.bindingsWhenFalse;
2343         }
2344 
2345         addBindings2Scope(tree, afterIfBindings);
2346 
2347         result = null;
2348     }
2349 
2350         void preFlow(JCTree tree) {
2351             attrRecover.doRecovery();
2352             new PostAttrAnalyzer() {
2353                 @Override
2354                 public void scan(JCTree tree) {
2355                     if (tree == null ||
2356                             (tree.type != null &&
2357                             tree.type == Type.stuckType)) {
2358                         //don't touch stuck expressions!
2359                         return;
2360                     }
2361                     super.scan(tree);
2362                 }
2363 
2364                 @Override
2365                 public void visitClassDef(JCClassDecl that) {
2366                     if (that.sym != null) {
2367                         // Method preFlow shouldn't visit class definitions
2368                         // that have not been entered and attributed.
2369                         // See JDK-8254557 and JDK-8203277 for more details.
2370                         super.visitClassDef(that);
2371                     }
2372                 }
2373 
2374                 @Override
2375                 public void visitLambda(JCLambda that) {
2376                     if (that.type != null) {
2377                         // Method preFlow shouldn't visit lambda expressions
2378                         // that have not been entered and attributed.
2379                         // See JDK-8254557 and JDK-8203277 for more details.
2380                         super.visitLambda(that);
2381                     }
2382                 }
2383             }.scan(tree);
2384         }
2385 
2386     public void visitExec(JCExpressionStatement tree) {
2387         //a fresh environment is required for 292 inference to work properly ---
2388         //see Infer.instantiatePolymorphicSignatureInstance()
2389         Env<AttrContext> localEnv = env.dup(tree);
2390         attribExpr(tree.expr, localEnv);
2391         result = null;
2392     }
2393 
2394     public void visitBreak(JCBreak tree) {
2395         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2396         result = null;
2397     }
2398 
2399     public void visitYield(JCYield tree) {
2400         if (env.info.yieldResult != null) {
2401             attribTree(tree.value, env, env.info.yieldResult);
2402             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2403         } else {
2404             log.error(tree.pos(), tree.value.hasTag(PARENS)
2405                     ? Errors.NoSwitchExpressionQualify
2406                     : Errors.NoSwitchExpression);
2407             attribTree(tree.value, env, unknownExprInfo);
2408         }
2409         result = null;
2410     }
2411 
2412     public void visitContinue(JCContinue tree) {
2413         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2414         result = null;
2415     }
2416     //where
2417         /** Return the target of a break, continue or yield statement,
2418          *  if it exists, report an error if not.
2419          *  Note: The target of a labelled break or continue is the
2420          *  (non-labelled) statement tree referred to by the label,
2421          *  not the tree representing the labelled statement itself.
2422          *
2423          *  @param pos     The position to be used for error diagnostics
2424          *  @param tag     The tag of the jump statement. This is either
2425          *                 Tree.BREAK or Tree.CONTINUE.
2426          *  @param label   The label of the jump statement, or null if no
2427          *                 label is given.
2428          *  @param env     The environment current at the jump statement.
2429          */
2430         private JCTree findJumpTarget(DiagnosticPosition pos,
2431                                                    JCTree.Tag tag,
2432                                                    Name label,
2433                                                    Env<AttrContext> env) {
2434             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2435 
2436             if (jumpTarget.snd != null) {
2437                 log.error(pos, jumpTarget.snd);
2438             }
2439 
2440             return jumpTarget.fst;
2441         }
2442         /** Return the target of a break or continue statement, if it exists,
2443          *  report an error if not.
2444          *  Note: The target of a labelled break or continue is the
2445          *  (non-labelled) statement tree referred to by the label,
2446          *  not the tree representing the labelled statement itself.
2447          *
2448          *  @param tag     The tag of the jump statement. This is either
2449          *                 Tree.BREAK or Tree.CONTINUE.
2450          *  @param label   The label of the jump statement, or null if no
2451          *                 label is given.
2452          *  @param env     The environment current at the jump statement.
2453          */
2454         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2455                                                                        Name label,
2456                                                                        Env<AttrContext> env) {
2457             // Search environments outwards from the point of jump.
2458             Env<AttrContext> env1 = env;
2459             JCDiagnostic.Error pendingError = null;
2460             LOOP:
2461             while (env1 != null) {
2462                 switch (env1.tree.getTag()) {
2463                     case LABELLED:
2464                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2465                         if (label == labelled.label) {
2466                             // If jump is a continue, check that target is a loop.
2467                             if (tag == CONTINUE) {
2468                                 if (!labelled.body.hasTag(DOLOOP) &&
2469                                         !labelled.body.hasTag(WHILELOOP) &&
2470                                         !labelled.body.hasTag(FORLOOP) &&
2471                                         !labelled.body.hasTag(FOREACHLOOP)) {
2472                                     pendingError = Errors.NotLoopLabel(label);
2473                                 }
2474                                 // Found labelled statement target, now go inwards
2475                                 // to next non-labelled tree.
2476                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2477                             } else {
2478                                 return Pair.of(labelled, pendingError);
2479                             }
2480                         }
2481                         break;
2482                     case DOLOOP:
2483                     case WHILELOOP:
2484                     case FORLOOP:
2485                     case FOREACHLOOP:
2486                         if (label == null) return Pair.of(env1.tree, pendingError);
2487                         break;
2488                     case SWITCH:
2489                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2490                         break;
2491                     case SWITCH_EXPRESSION:
2492                         if (tag == YIELD) {
2493                             return Pair.of(env1.tree, null);
2494                         } else if (tag == BREAK) {
2495                             pendingError = Errors.BreakOutsideSwitchExpression;
2496                         } else {
2497                             pendingError = Errors.ContinueOutsideSwitchExpression;
2498                         }
2499                         break;
2500                     case LAMBDA:
2501                     case METHODDEF:
2502                     case CLASSDEF:
2503                         break LOOP;
2504                     default:
2505                 }
2506                 env1 = env1.next;
2507             }
2508             if (label != null)
2509                 return Pair.of(null, Errors.UndefLabel(label));
2510             else if (pendingError != null)
2511                 return Pair.of(null, pendingError);
2512             else if (tag == CONTINUE)
2513                 return Pair.of(null, Errors.ContOutsideLoop);
2514             else
2515                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2516         }
2517 
2518     public void visitReturn(JCReturn tree) {
2519         // Check that there is an enclosing method which is
2520         // nested within than the enclosing class.
2521         if (env.info.returnResult == null) {
2522             log.error(tree.pos(), Errors.RetOutsideMeth);
2523         } else if (env.info.yieldResult != null) {
2524             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2525             if (tree.expr != null) {
2526                 attribExpr(tree.expr, env, env.info.yieldResult.pt);
2527             }
2528         } else if (!env.info.isLambda &&
2529                 env.enclMethod != null &&
2530                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2531             log.error(env.enclMethod,
2532                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2533         } else {
2534             // Attribute return expression, if it exists, and check that
2535             // it conforms to result type of enclosing method.
2536             if (tree.expr != null) {
2537                 if (env.info.returnResult.pt.hasTag(VOID)) {
2538                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2539                               diags.fragment(Fragments.UnexpectedRetVal));
2540                 }
2541                 attribTree(tree.expr, env, env.info.returnResult);
2542             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2543                     !env.info.returnResult.pt.hasTag(NONE)) {
2544                 env.info.returnResult.checkContext.report(tree.pos(),
2545                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2546             }
2547         }
2548         result = null;
2549     }
2550 
2551     public void visitThrow(JCThrow tree) {
2552         Type owntype = attribExpr(tree.expr, env, Type.noType);
2553         chk.checkType(tree, owntype, syms.throwableType);
2554         result = null;
2555     }
2556 
2557     public void visitAssert(JCAssert tree) {
2558         attribExpr(tree.cond, env, syms.booleanType);
2559         if (tree.detail != null) {
2560             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2561         }
2562         result = null;
2563     }
2564 
2565      /** Visitor method for method invocations.
2566      *  NOTE: The method part of an application will have in its type field
2567      *        the return type of the method, not the method's type itself!
2568      */
2569     public void visitApply(JCMethodInvocation tree) {
2570         // The local environment of a method application is
2571         // a new environment nested in the current one.
2572         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2573 
2574         // The types of the actual method arguments.
2575         List<Type> argtypes;
2576 
2577         // The types of the actual method type arguments.
2578         List<Type> typeargtypes = null;
2579 
2580         Name methName = TreeInfo.name(tree.meth);
2581 
2582         boolean isConstructorCall =
2583             methName == names._this || methName == names._super;
2584 
2585         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2586         if (isConstructorCall) {
2587 
2588             // Attribute arguments, yielding list of argument types.
2589             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2590             argtypes = argtypesBuf.toList();
2591             typeargtypes = attribTypes(tree.typeargs, localEnv);
2592 
2593             // Done with this()/super() parameters. End of constructor prologue.
2594             env.info.ctorPrologue = false;
2595 
2596             // Variable `site' points to the class in which the called
2597             // constructor is defined.
2598             Type site = env.enclClass.sym.type;
2599             if (methName == names._super) {
2600                 if (site == syms.objectType) {
2601                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2602                     site = types.createErrorType(syms.objectType);
2603                 } else {
2604                     site = types.supertype(site);
2605                 }
2606             }
2607 
2608             if (site.hasTag(CLASS)) {
2609                 Type encl = site.getEnclosingType();
2610                 while (encl != null && encl.hasTag(TYPEVAR))
2611                     encl = encl.getUpperBound();
2612                 if (encl.hasTag(CLASS)) {
2613                     // we are calling a nested class
2614 
2615                     if (tree.meth.hasTag(SELECT)) {
2616                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2617 
2618                         // We are seeing a prefixed call, of the form
2619                         //     <expr>.super(...).
2620                         // Check that the prefix expression conforms
2621                         // to the outer instance type of the class.
2622                         chk.checkRefType(qualifier.pos(),
2623                                          attribExpr(qualifier, localEnv,
2624                                                     encl));
2625                     }
2626                 } else if (tree.meth.hasTag(SELECT)) {
2627                     log.error(tree.meth.pos(),
2628                               Errors.IllegalQualNotIcls(site.tsym));
2629                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2630                 }
2631 
2632                 if (tree.meth.hasTag(IDENT)) {
2633                     // non-qualified super(...) call; check whether explicit constructor
2634                     // invocation is well-formed. If the super class is an inner class,
2635                     // make sure that an appropriate implicit qualifier exists. If the super
2636                     // class is a local class, make sure that the current class is defined
2637                     // in the same context as the local class.
2638                     checkNewInnerClass(tree.meth.pos(), localEnv, site, true);
2639                 }
2640 
2641                 // if we're calling a java.lang.Enum constructor,
2642                 // prefix the implicit String and int parameters
2643                 if (site.tsym == syms.enumSym)
2644                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
2645 
2646                 // Resolve the called constructor under the assumption
2647                 // that we are referring to a superclass instance of the
2648                 // current instance (JLS ???).
2649                 boolean selectSuperPrev = localEnv.info.selectSuper;
2650                 localEnv.info.selectSuper = true;
2651                 localEnv.info.pendingResolutionPhase = null;
2652                 Symbol sym = rs.resolveConstructor(
2653                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
2654                 localEnv.info.selectSuper = selectSuperPrev;
2655 
2656                 // Set method symbol to resolved constructor...
2657                 TreeInfo.setSymbol(tree.meth, sym);
2658 
2659                 // ...and check that it is legal in the current context.
2660                 // (this will also set the tree's type)
2661                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2662                 checkId(tree.meth, site, sym, localEnv,
2663                         new ResultInfo(kind, mpt));
2664             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
2665                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2666             }
2667             // Otherwise, `site' is an error type and we do nothing
2668             result = tree.type = syms.voidType;
2669         } else {
2670             // Otherwise, we are seeing a regular method call.
2671             // Attribute the arguments, yielding list of argument types, ...
2672             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2673             argtypes = argtypesBuf.toList();
2674             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
2675 
2676             // ... and attribute the method using as a prototype a methodtype
2677             // whose formal argument types is exactly the list of actual
2678             // arguments (this will also set the method symbol).
2679             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2680             localEnv.info.pendingResolutionPhase = null;
2681             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
2682 
2683             // Compute the result type.
2684             Type restype = mtype.getReturnType();
2685             if (restype.hasTag(WILDCARD))
2686                 throw new AssertionError(mtype);
2687 
2688             Type qualifier = (tree.meth.hasTag(SELECT))
2689                     ? ((JCFieldAccess) tree.meth).selected.type
2690                     : env.enclClass.sym.type;
2691             Symbol msym = TreeInfo.symbol(tree.meth);
2692             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
2693 
2694             chk.checkRefTypes(tree.typeargs, typeargtypes);
2695 
2696             // Check that value of resulting type is admissible in the
2697             // current context.  Also, capture the return type
2698             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
2699             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
2700         }
2701         chk.checkRequiresIdentity(tree, env.info.lint);
2702         chk.validate(tree.typeargs, localEnv);
2703     }
2704     //where
2705         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
2706             if (msym != null &&
2707                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
2708                     methodName == names.getClass &&
2709                     argtypes.isEmpty()) {
2710                 // as a special case, x.getClass() has type Class<? extends |X|>
2711                 return new ClassType(restype.getEnclosingType(),
2712                         List.of(new WildcardType(types.erasure(qualifierType.baseType()),
2713                                 BoundKind.EXTENDS,
2714                                 syms.boundClass)),
2715                         restype.tsym,
2716                         restype.getMetadata());
2717             } else if (msym != null &&
2718                     msym.owner == syms.arrayClass &&
2719                     methodName == names.clone &&
2720                     types.isArray(qualifierType)) {
2721                 // as a special case, array.clone() has a result that is
2722                 // the same as static type of the array being cloned
2723                 return qualifierType;
2724             } else {
2725                 return restype;
2726             }
2727         }
2728 
2729         /** Obtain a method type with given argument types.
2730          */
2731         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
2732             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
2733             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
2734         }
2735 
2736     public void visitNewClass(final JCNewClass tree) {
2737         Type owntype = types.createErrorType(tree.type);
2738 
2739         // The local environment of a class creation is
2740         // a new environment nested in the current one.
2741         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2742 
2743         // The anonymous inner class definition of the new expression,
2744         // if one is defined by it.
2745         JCClassDecl cdef = tree.def;
2746 
2747         // If enclosing class is given, attribute it, and
2748         // complete class name to be fully qualified
2749         JCExpression clazz = tree.clazz; // Class field following new
2750         JCExpression clazzid;            // Identifier in class field
2751         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
2752         annoclazzid = null;
2753 
2754         if (clazz.hasTag(TYPEAPPLY)) {
2755             clazzid = ((JCTypeApply) clazz).clazz;
2756             if (clazzid.hasTag(ANNOTATED_TYPE)) {
2757                 annoclazzid = (JCAnnotatedType) clazzid;
2758                 clazzid = annoclazzid.underlyingType;
2759             }
2760         } else {
2761             if (clazz.hasTag(ANNOTATED_TYPE)) {
2762                 annoclazzid = (JCAnnotatedType) clazz;
2763                 clazzid = annoclazzid.underlyingType;
2764             } else {
2765                 clazzid = clazz;
2766             }
2767         }
2768 
2769         JCExpression clazzid1 = clazzid; // The same in fully qualified form
2770 
2771         if (tree.encl != null) {
2772             // We are seeing a qualified new, of the form
2773             //    <expr>.new C <...> (...) ...
2774             // In this case, we let clazz stand for the name of the
2775             // allocated class C prefixed with the type of the qualifier
2776             // expression, so that we can
2777             // resolve it with standard techniques later. I.e., if
2778             // <expr> has type T, then <expr>.new C <...> (...)
2779             // yields a clazz T.C.
2780             Type encltype = chk.checkRefType(tree.encl.pos(),
2781                                              attribExpr(tree.encl, env));
2782             // TODO 308: in <expr>.new C, do we also want to add the type annotations
2783             // from expr to the combined type, or not? Yes, do this.
2784             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
2785                                                  ((JCIdent) clazzid).name);
2786 
2787             clazzid1.endpos = clazzid.getEndPosition();
2788             if (clazz.hasTag(ANNOTATED_TYPE)) {
2789                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
2790                 List<JCAnnotation> annos = annoType.annotations;
2791 
2792                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
2793                     clazzid1 = make.at(tree.pos).
2794                         TypeApply(clazzid1,
2795                                   ((JCTypeApply) clazz).arguments);
2796                 }
2797 
2798                 clazzid1 = make.at(tree.pos).
2799                     AnnotatedType(annos, clazzid1);
2800             } else if (clazz.hasTag(TYPEAPPLY)) {
2801                 clazzid1 = make.at(tree.pos).
2802                     TypeApply(clazzid1,
2803                               ((JCTypeApply) clazz).arguments);
2804             }
2805 
2806             clazz = clazzid1;
2807         }
2808 
2809         // Attribute clazz expression and store
2810         // symbol + type back into the attributed tree.
2811         Type clazztype = TreeInfo.isEnumInit(env.tree) ?
2812             attribIdentAsEnumType(env, (JCIdent)clazz) :
2813             attribType(clazz, env);
2814 
2815         clazztype = chk.checkDiamond(tree, clazztype);
2816         chk.validate(clazz, localEnv);
2817         if (tree.encl != null) {
2818             // We have to work in this case to store
2819             // symbol + type back into the attributed tree.
2820             tree.clazz.type = clazztype;
2821             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
2822             clazzid.type = ((JCIdent) clazzid).sym.type;
2823             if (annoclazzid != null) {
2824                 annoclazzid.type = clazzid.type;
2825             }
2826             if (!clazztype.isErroneous()) {
2827                 if (cdef != null && clazztype.tsym.isInterface()) {
2828                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
2829                 } else if (clazztype.tsym.isStatic()) {
2830                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
2831                 }
2832             }
2833         } else {
2834             // Check for the existence of an apropos outer instance
2835             checkNewInnerClass(tree.pos(), env, clazztype, false);
2836         }
2837 
2838         checkBreakTree(tree.clazz, localEnv);
2839 
2840         // Attribute constructor arguments.
2841         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2842         final KindSelector pkind =
2843             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2844         List<Type> argtypes = argtypesBuf.toList();
2845         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
2846 
2847         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
2848             // Enums may not be instantiated except implicitly
2849             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
2850                 (!env.tree.hasTag(VARDEF) ||
2851                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
2852                  ((JCVariableDecl) env.tree).init != tree))
2853                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
2854 
2855             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
2856                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
2857             boolean skipNonDiamondPath = false;
2858             // Check that class is not abstract
2859             if (cdef == null && !tree.classDeclRemoved() && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
2860                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
2861                 log.error(tree.pos(),
2862                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
2863                 skipNonDiamondPath = true;
2864             } else if (cdef != null && clazztype.tsym.isInterface()) {
2865                 // Check that no constructor arguments are given to
2866                 // anonymous classes implementing an interface
2867                 if (!argtypes.isEmpty())
2868                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
2869 
2870                 if (!typeargtypes.isEmpty())
2871                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
2872 
2873                 // Error recovery: pretend no arguments were supplied.
2874                 argtypes = List.nil();
2875                 typeargtypes = List.nil();
2876                 skipNonDiamondPath = true;
2877             }
2878             if (TreeInfo.isDiamond(tree)) {
2879                 ClassType site = new ClassType(clazztype.getEnclosingType(),
2880                             clazztype.tsym.type.getTypeArguments(),
2881                                                clazztype.tsym,
2882                                                clazztype.getMetadata());
2883 
2884                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
2885                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
2886                 diamondEnv.info.pendingResolutionPhase = null;
2887 
2888                 //if the type of the instance creation expression is a class type
2889                 //apply method resolution inference (JLS 15.12.2.7). The return type
2890                 //of the resolved constructor will be a partially instantiated type
2891                 Symbol constructor = rs.resolveDiamond(tree.pos(),
2892                             diamondEnv,
2893                             site,
2894                             argtypes,
2895                             typeargtypes);
2896                 tree.constructor = constructor.baseSymbol();
2897 
2898                 final TypeSymbol csym = clazztype.tsym;
2899                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
2900                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
2901                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
2902                 constructorType = checkId(tree, site,
2903                         constructor,
2904                         diamondEnv,
2905                         diamondResult);
2906 
2907                 tree.clazz.type = types.createErrorType(clazztype);
2908                 if (!constructorType.isErroneous()) {
2909                     tree.clazz.type = clazz.type = constructorType.getReturnType();
2910                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
2911                 }
2912                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
2913             }
2914 
2915             // Resolve the called constructor under the assumption
2916             // that we are referring to a superclass instance of the
2917             // current instance (JLS ???).
2918             else if (!skipNonDiamondPath) {
2919                 //the following code alters some of the fields in the current
2920                 //AttrContext - hence, the current context must be dup'ed in
2921                 //order to avoid downstream failures
2922                 Env<AttrContext> rsEnv = localEnv.dup(tree);
2923                 rsEnv.info.selectSuper = cdef != null;
2924                 rsEnv.info.pendingResolutionPhase = null;
2925                 tree.constructor = rs.resolveConstructor(
2926                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
2927                 if (cdef == null) { //do not check twice!
2928                     tree.constructorType = checkId(tree,
2929                             clazztype,
2930                             tree.constructor,
2931                             rsEnv,
2932                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
2933                     if (rsEnv.info.lastResolveVarargs())
2934                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
2935                 }
2936             }
2937 
2938             chk.checkRequiresIdentity(tree, env.info.lint);
2939 
2940             if (cdef != null) {
2941                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
2942                 return;
2943             }
2944 
2945             if (tree.constructor != null && tree.constructor.kind == MTH)
2946                 owntype = clazztype;
2947         }
2948         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2949         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2950         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
2951             //we need to wait for inference to finish and then replace inference vars in the constructor type
2952             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
2953                     instantiatedContext -> {
2954                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2955                     });
2956         }
2957         chk.validate(tree.typeargs, localEnv);
2958     }
2959 
2960         // where
2961         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
2962                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
2963                                                    List<Type> argtypes, List<Type> typeargtypes,
2964                                                    KindSelector pkind) {
2965             // We are seeing an anonymous class instance creation.
2966             // In this case, the class instance creation
2967             // expression
2968             //
2969             //    E.new <typeargs1>C<typargs2>(args) { ... }
2970             //
2971             // is represented internally as
2972             //
2973             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
2974             //
2975             // This expression is then *transformed* as follows:
2976             //
2977             // (1) add an extends or implements clause
2978             // (2) add a constructor.
2979             //
2980             // For instance, if C is a class, and ET is the type of E,
2981             // the expression
2982             //
2983             //    E.new <typeargs1>C<typargs2>(args) { ... }
2984             //
2985             // is translated to (where X is a fresh name and typarams is the
2986             // parameter list of the super constructor):
2987             //
2988             //   new <typeargs1>X(<*nullchk*>E, args) where
2989             //     X extends C<typargs2> {
2990             //       <typarams> X(ET e, args) {
2991             //         e.<typeargs1>super(args)
2992             //       }
2993             //       ...
2994             //     }
2995             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2996             Type enclType = clazztype.getEnclosingType();
2997             if (enclType != null &&
2998                     enclType.hasTag(CLASS) &&
2999                     !chk.checkDenotable((ClassType)enclType)) {
3000                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
3001             }
3002             final boolean isDiamond = TreeInfo.isDiamond(tree);
3003             if (isDiamond
3004                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
3005                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
3006                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
3007                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
3008                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
3009                         instantiatedContext -> {
3010                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
3011                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
3012                             ResultInfo prevResult = this.resultInfo;
3013                             try {
3014                                 this.resultInfo = resultInfoForClassDefinition;
3015                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
3016                                         dupLocalEnv, argtypes, typeargtypes, pkind);
3017                             } finally {
3018                                 this.resultInfo = prevResult;
3019                             }
3020                         });
3021             } else {
3022                 if (isDiamond && clazztype.hasTag(CLASS)) {
3023                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
3024                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
3025                         // One or more types inferred in the previous steps is non-denotable.
3026                         Fragment fragment = Diamond(clazztype.tsym);
3027                         log.error(tree.clazz.pos(),
3028                                 Errors.CantApplyDiamond1(
3029                                         fragment,
3030                                         invalidDiamondArgs.size() > 1 ?
3031                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
3032                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
3033                     }
3034                     // For <>(){}, inferred types must also be accessible.
3035                     for (Type t : clazztype.getTypeArguments()) {
3036                         rs.checkAccessibleType(env, t);
3037                     }
3038                 }
3039 
3040                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
3041                 // false for isInterface call even when the original type is an interface.
3042                 boolean implementing = clazztype.tsym.isInterface() ||
3043                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
3044                         clazztype.getOriginalType().tsym.isInterface();
3045 
3046                 if (implementing) {
3047                     cdef.implementing = List.of(clazz);
3048                 } else {
3049                     cdef.extending = clazz;
3050                 }
3051 
3052                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3053                     rs.isSerializable(clazztype)) {
3054                     localEnv.info.isSerializable = true;
3055                 }
3056 
3057                 attribStat(cdef, localEnv);
3058 
3059                 List<Type> finalargtypes;
3060                 // If an outer instance is given,
3061                 // prefix it to the constructor arguments
3062                 // and delete it from the new expression
3063                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
3064                     finalargtypes = argtypes.prepend(tree.encl.type);
3065                 } else {
3066                     finalargtypes = argtypes;
3067                 }
3068 
3069                 // Reassign clazztype and recompute constructor. As this necessarily involves
3070                 // another attribution pass for deferred types in the case of <>, replicate
3071                 // them. Original arguments have right decorations already.
3072                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3073                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3074                 }
3075 
3076                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3077                                                     : cdef.sym.type;
3078                 Symbol sym = tree.constructor = rs.resolveConstructor(
3079                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3080                 Assert.check(!sym.kind.isResolutionError());
3081                 tree.constructor = sym;
3082                 tree.constructorType = checkId(tree,
3083                         clazztype,
3084                         tree.constructor,
3085                         localEnv,
3086                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3087             }
3088             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3089                                 clazztype : types.createErrorType(tree.type);
3090             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3091             chk.validate(tree.typeargs, localEnv);
3092         }
3093 
3094         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3095             return new Check.NestedCheckContext(checkContext) {
3096                 @Override
3097                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3098                     enclosingContext.report(clazz.clazz,
3099                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3100                 }
3101             };
3102         }
3103 
3104         void checkNewInnerClass(DiagnosticPosition pos, Env<AttrContext> env, Type type, boolean isSuper) {
3105             boolean isLocal = type.tsym.owner.kind == VAR || type.tsym.owner.kind == MTH;
3106             if ((type.tsym.flags() & (INTERFACE | ENUM | RECORD)) != 0 ||
3107                     (!isLocal && !type.tsym.isInner()) ||
3108                     (isSuper && env.enclClass.sym.isAnonymous())) {
3109                 // nothing to check
3110                 return;
3111             }
3112             Symbol res = isLocal ?
3113                     rs.findLocalClassOwner(env, type.tsym) :
3114                     rs.findSelfContaining(pos, env, type.getEnclosingType().tsym, isSuper);
3115             if (res.exists()) {
3116                 rs.accessBase(res, pos, env.enclClass.sym.type, names._this, true);
3117             } else {
3118                 log.error(pos, Errors.EnclClassRequired(type.tsym));
3119             }
3120         }
3121 
3122     /** Make an attributed null check tree.
3123      */
3124     public JCExpression makeNullCheck(JCExpression arg) {
3125         // optimization: new Outer() can never be null; skip null check
3126         if (arg.getTag() == NEWCLASS)
3127             return arg;
3128         // optimization: X.this is never null; skip null check
3129         Name name = TreeInfo.name(arg);
3130         if (name == names._this || name == names._super) return arg;
3131 
3132         JCTree.Tag optag = NULLCHK;
3133         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3134         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3135         tree.type = arg.type;
3136         return tree;
3137     }
3138 
3139     public void visitNewArray(JCNewArray tree) {
3140         Type owntype = types.createErrorType(tree.type);
3141         Env<AttrContext> localEnv = env.dup(tree);
3142         Type elemtype;
3143         if (tree.elemtype != null) {
3144             elemtype = attribType(tree.elemtype, localEnv);
3145             chk.validate(tree.elemtype, localEnv);
3146             owntype = elemtype;
3147             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3148                 attribExpr(l.head, localEnv, syms.intType);
3149                 owntype = new ArrayType(owntype, syms.arrayClass);
3150             }
3151         } else {
3152             // we are seeing an untyped aggregate { ... }
3153             // this is allowed only if the prototype is an array
3154             if (pt().hasTag(ARRAY)) {
3155                 elemtype = types.elemtype(pt());
3156             } else {
3157                 if (!pt().hasTag(ERROR) &&
3158                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3159                     log.error(tree.pos(),
3160                               Errors.IllegalInitializerForType(pt()));
3161                 }
3162                 elemtype = types.createErrorType(pt());
3163             }
3164         }
3165         if (tree.elems != null) {
3166             attribExprs(tree.elems, localEnv, elemtype);
3167             owntype = new ArrayType(elemtype, syms.arrayClass);
3168         }
3169         if (!types.isReifiable(elemtype))
3170             log.error(tree.pos(), Errors.GenericArrayCreation);
3171         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3172     }
3173 
3174     /*
3175      * A lambda expression can only be attributed when a target-type is available.
3176      * In addition, if the target-type is that of a functional interface whose
3177      * descriptor contains inference variables in argument position the lambda expression
3178      * is 'stuck' (see DeferredAttr).
3179      */
3180     @Override
3181     public void visitLambda(final JCLambda that) {
3182         boolean wrongContext = false;
3183         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3184             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3185                 //lambda only allowed in assignment or method invocation/cast context
3186                 log.error(that.pos(), Errors.UnexpectedLambda);
3187             }
3188             resultInfo = recoveryInfo;
3189             wrongContext = true;
3190         }
3191         //create an environment for attribution of the lambda expression
3192         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3193         boolean needsRecovery =
3194                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3195         try {
3196             if (needsRecovery && rs.isSerializable(pt())) {
3197                 localEnv.info.isSerializable = true;
3198                 localEnv.info.isSerializableLambda = true;
3199             }
3200             List<Type> explicitParamTypes = null;
3201             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3202                 //attribute lambda parameters
3203                 attribStats(that.params, localEnv);
3204                 explicitParamTypes = TreeInfo.types(that.params);
3205             }
3206 
3207             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3208             Type currentTarget = targetInfo.target;
3209             Type lambdaType = targetInfo.descriptor;
3210 
3211             if (currentTarget.isErroneous()) {
3212                 result = that.type = currentTarget;
3213                 return;
3214             }
3215 
3216             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3217 
3218             if (lambdaType.hasTag(FORALL)) {
3219                 //lambda expression target desc cannot be a generic method
3220                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3221                                                                     kindName(currentTarget.tsym),
3222                                                                     currentTarget.tsym);
3223                 resultInfo.checkContext.report(that, diags.fragment(msg));
3224                 result = that.type = types.createErrorType(pt());
3225                 return;
3226             }
3227 
3228             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3229                 //add param type info in the AST
3230                 List<Type> actuals = lambdaType.getParameterTypes();
3231                 List<JCVariableDecl> params = that.params;
3232 
3233                 boolean arityMismatch = false;
3234 
3235                 while (params.nonEmpty()) {
3236                     if (actuals.isEmpty()) {
3237                         //not enough actuals to perform lambda parameter inference
3238                         arityMismatch = true;
3239                     }
3240                     //reset previously set info
3241                     Type argType = arityMismatch ?
3242                             syms.errType :
3243                             actuals.head;
3244                     if (params.head.type == null &&
3245                         params.head.isImplicitlyTyped()) { //error recovery
3246                         params.head.type = argType;
3247                         setupImplicitlyTypedVariable(params.head, argType);
3248                     }
3249                     params.head.sym = null;
3250                     actuals = actuals.isEmpty() ?
3251                             actuals :
3252                             actuals.tail;
3253                     params = params.tail;
3254                 }
3255 
3256                 //attribute lambda parameters
3257                 attribStats(that.params, localEnv);
3258 
3259                 if (arityMismatch) {
3260                     resultInfo.checkContext.report(that, diags.fragment(Fragments.WrongNumberArgsInLambda(currentTarget.tsym)));
3261                         result = that.type = types.createErrorType(currentTarget);
3262                         return;
3263                 }
3264             }
3265 
3266             //from this point on, no recovery is needed; if we are in assignment context
3267             //we will be able to attribute the whole lambda body, regardless of errors;
3268             //if we are in a 'check' method context, and the lambda is not compatible
3269             //with the target-type, it will be recovered anyway in Attr.checkId
3270             needsRecovery = false;
3271 
3272             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3273                     lambdaBodyResult(that, lambdaType, resultInfo);
3274 
3275             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3276                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3277             } else {
3278                 JCBlock body = (JCBlock)that.body;
3279 
3280                 checkBreakTree(body, localEnv);
3281                 attribStats(body.stats, localEnv);
3282             }
3283 
3284             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3285 
3286             boolean isSpeculativeRound =
3287                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3288 
3289             preFlow(that);
3290             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3291 
3292             that.type = currentTarget; //avoids recovery at this stage
3293             checkLambdaCompatible(that, lambdaType, currentTarget.tsym, resultInfo.checkContext);
3294 
3295             if (!isSpeculativeRound) {
3296                 //add thrown types as bounds to the thrown types free variables if needed:
3297                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3298                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3299                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3300                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3301                     }
3302                 }
3303 
3304                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3305             }
3306             result = wrongContext ? that.type = types.createErrorType(pt())
3307                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3308         } catch (Types.FunctionDescriptorLookupError ex) {
3309             JCDiagnostic cause = ex.getDiagnostic();
3310             resultInfo.checkContext.report(that, cause);
3311             result = that.type = types.createErrorType(pt());
3312             return;
3313         } catch (CompletionFailure cf) {
3314             chk.completionError(that.pos(), cf);
3315         } catch (Throwable t) {
3316             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3317             //as that would likely cause the same exception again.
3318             needsRecovery = false;
3319             throw t;
3320         } finally {
3321             localEnv.info.scope.leave();
3322             if (needsRecovery) {
3323                 Type prevResult = result;
3324                 try {
3325                     attribTree(that, env, recoveryInfo);
3326                 } finally {
3327                     if (result == Type.recoveryType) {
3328                         result = prevResult;
3329                     }
3330                 }
3331             }
3332         }
3333     }
3334     //where
3335         class TargetInfo {
3336             Type target;
3337             Type descriptor;
3338 
3339             public TargetInfo(Type target, Type descriptor) {
3340                 this.target = target;
3341                 this.descriptor = descriptor;
3342             }
3343         }
3344 
3345         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3346             Type lambdaType;
3347             Type currentTarget = resultInfo.pt;
3348             if (resultInfo.pt != Type.recoveryType) {
3349                 /* We need to adjust the target. If the target is an
3350                  * intersection type, for example: SAM & I1 & I2 ...
3351                  * the target will be updated to SAM
3352                  */
3353                 currentTarget = targetChecker.visit(currentTarget, that);
3354                 if (!currentTarget.isIntersection()) {
3355                     if (explicitParamTypes != null) {
3356                         currentTarget = infer.instantiateFunctionalInterface(that,
3357                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3358                     }
3359                     currentTarget = types.removeWildcards(currentTarget);
3360                     lambdaType = types.findDescriptorType(currentTarget);
3361                 } else {
3362                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3363                     ListBuffer<Type> components = new ListBuffer<>();
3364                     for (Type bound : ict.getExplicitComponents()) {
3365                         if (explicitParamTypes != null) {
3366                             try {
3367                                 bound = infer.instantiateFunctionalInterface(that,
3368                                         bound, explicitParamTypes, resultInfo.checkContext);
3369                             } catch (FunctionDescriptorLookupError t) {
3370                                 // do nothing
3371                             }
3372                         }
3373                         if (bound.tsym != syms.objectType.tsym && (!bound.isInterface() || (bound.tsym.flags() & ANNOTATION) != 0)) {
3374                             // bound must be j.l.Object or an interface, but not an annotation
3375                             reportIntersectionError(that, "not.an.intf.component", bound);
3376                         }
3377                         bound = types.removeWildcards(bound);
3378                         components.add(bound);
3379                     }
3380                     currentTarget = types.makeIntersectionType(components.toList());
3381                     currentTarget.tsym.flags_field |= INTERFACE;
3382                     lambdaType = types.findDescriptorType(currentTarget);
3383                 }
3384 
3385             } else {
3386                 currentTarget = Type.recoveryType;
3387                 lambdaType = fallbackDescriptorType(that);
3388             }
3389             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3390                 //lambda expression target desc cannot be a generic method
3391                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3392                                                                     kindName(currentTarget.tsym),
3393                                                                     currentTarget.tsym);
3394                 resultInfo.checkContext.report(that, diags.fragment(msg));
3395                 currentTarget = types.createErrorType(pt());
3396             }
3397             return new TargetInfo(currentTarget, lambdaType);
3398         }
3399 
3400         private void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) {
3401              resultInfo.checkContext.report(pos,
3402                  diags.fragment(Fragments.BadIntersectionTargetForFunctionalExpr(diags.fragment(key, args))));
3403         }
3404 
3405         void preFlow(JCLambda tree) {
3406             attrRecover.doRecovery();
3407             new PostAttrAnalyzer() {
3408                 @Override
3409                 public void scan(JCTree tree) {
3410                     if (tree == null ||
3411                             (tree.type != null &&
3412                             tree.type == Type.stuckType)) {
3413                         //don't touch stuck expressions!
3414                         return;
3415                     }
3416                     super.scan(tree);
3417                 }
3418 
3419                 @Override
3420                 public void visitClassDef(JCClassDecl that) {
3421                     // or class declaration trees!
3422                 }
3423 
3424                 public void visitLambda(JCLambda that) {
3425                     // or lambda expressions!
3426                 }
3427             }.scan(tree.body);
3428         }
3429 
3430         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3431 
3432             @Override
3433             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3434                 return t.isIntersection() ?
3435                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3436             }
3437 
3438             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3439                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3440                 return ict;
3441             }
3442 
3443             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3444                 ListBuffer<Type> targs = new ListBuffer<>();
3445                 ListBuffer<Type> supertypes = new ListBuffer<>();
3446                 for (Type i : ict.interfaces_field) {
3447                     if (i.isParameterized()) {
3448                         targs.appendList(i.tsym.type.allparams());
3449                     }
3450                     supertypes.append(i.tsym.type);
3451                 }
3452                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3453                 notionalIntf.allparams_field = targs.toList();
3454                 notionalIntf.tsym.flags_field |= INTERFACE;
3455                 return notionalIntf.tsym;
3456             }
3457         };
3458 
3459         private Type fallbackDescriptorType(JCExpression tree) {
3460             switch (tree.getTag()) {
3461                 case LAMBDA:
3462                     JCLambda lambda = (JCLambda)tree;
3463                     List<Type> argtypes = List.nil();
3464                     for (JCVariableDecl param : lambda.params) {
3465                         argtypes = !param.isImplicitlyTyped() && param.vartype.type != null ?
3466                                 argtypes.append(param.vartype.type) :
3467                                 argtypes.append(syms.errType);
3468                     }
3469                     return new MethodType(argtypes, Type.recoveryType,
3470                             List.of(syms.throwableType), syms.methodClass);
3471                 case REFERENCE:
3472                     return new MethodType(List.nil(), Type.recoveryType,
3473                             List.of(syms.throwableType), syms.methodClass);
3474                 default:
3475                     Assert.error("Cannot get here!");
3476             }
3477             return null;
3478         }
3479 
3480         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3481                 final InferenceContext inferenceContext, final Type... ts) {
3482             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3483         }
3484 
3485         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3486                 final InferenceContext inferenceContext, final List<Type> ts) {
3487             if (inferenceContext.free(ts)) {
3488                 inferenceContext.addFreeTypeListener(ts,
3489                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3490             } else {
3491                 for (Type t : ts) {
3492                     rs.checkAccessibleType(env, t);
3493                 }
3494             }
3495         }
3496 
3497         /**
3498          * Lambda/method reference have a special check context that ensures
3499          * that i.e. a lambda return type is compatible with the expected
3500          * type according to both the inherited context and the assignment
3501          * context.
3502          */
3503         class FunctionalReturnContext extends Check.NestedCheckContext {
3504 
3505             FunctionalReturnContext(CheckContext enclosingContext) {
3506                 super(enclosingContext);
3507             }
3508 
3509             @Override
3510             public boolean compatible(Type found, Type req, Warner warn) {
3511                 //return type must be compatible in both current context and assignment context
3512                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3513             }
3514 
3515             @Override
3516             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3517                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3518             }
3519         }
3520 
3521         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3522 
3523             JCExpression expr;
3524             boolean expStmtExpected;
3525 
3526             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3527                 super(enclosingContext);
3528                 this.expr = expr;
3529             }
3530 
3531             @Override
3532             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3533                 if (expStmtExpected) {
3534                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3535                 } else {
3536                     super.report(pos, details);
3537                 }
3538             }
3539 
3540             @Override
3541             public boolean compatible(Type found, Type req, Warner warn) {
3542                 //a void return is compatible with an expression statement lambda
3543                 if (req.hasTag(VOID)) {
3544                     expStmtExpected = true;
3545                     return TreeInfo.isExpressionStatement(expr);
3546                 } else {
3547                     return super.compatible(found, req, warn);
3548                 }
3549             }
3550         }
3551 
3552         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3553             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3554                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3555                     new FunctionalReturnContext(resultInfo.checkContext);
3556 
3557             return descriptor.getReturnType() == Type.recoveryType ?
3558                     recoveryInfo :
3559                     new ResultInfo(KindSelector.VAL,
3560                             descriptor.getReturnType(), funcContext);
3561         }
3562 
3563         /**
3564         * Lambda compatibility. Check that given return types, thrown types, parameter types
3565         * are compatible with the expected functional interface descriptor. This means that:
3566         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3567         * types must be compatible with the return type of the expected descriptor.
3568         */
3569         void checkLambdaCompatible(JCLambda tree, Type descriptor, TypeSymbol target, CheckContext checkContext) {
3570             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3571 
3572             //return values have already been checked - but if lambda has no return
3573             //values, we must ensure that void/value compatibility is correct;
3574             //this amounts at checking that, if a lambda body can complete normally,
3575             //the descriptor's return type must be void
3576             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3577                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3578                 Fragment msg =
3579                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3580                 checkContext.report(tree,
3581                                     diags.fragment(msg));
3582             }
3583 
3584             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3585             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3586                 checkContext.report(tree, diags.fragment(argTypes.size() != tree.params.size()
3587                         ? Fragments.WrongNumberArgsInLambda(target)
3588                         : Fragments.IncompatibleArgTypesInLambda(argTypes, TreeInfo.types(tree.params))));
3589             }
3590         }
3591 
3592         /* This method returns an environment to be used to attribute a lambda
3593          * expression.
3594          *
3595          * The owner of this environment is a method symbol. If the current owner
3596          * is not a method (e.g. if the lambda occurs in a field initializer), then
3597          * a synthetic method symbol owner is created.
3598          */
3599         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3600             Env<AttrContext> lambdaEnv;
3601             Symbol owner = env.info.scope.owner;
3602             if (owner.kind == VAR && owner.owner.kind == TYP) {
3603                 // If the lambda is nested in a field initializer, we need to create a fake init method.
3604                 // Uniqueness of this symbol is not important (as e.g. annotations will be added on the
3605                 // init symbol's owner).
3606                 ClassSymbol enclClass = owner.enclClass();
3607                 Name initName = owner.isStatic() ? names.clinit : names.init;
3608                 MethodSymbol initSym = new MethodSymbol(BLOCK | (owner.isStatic() ? STATIC : 0) | SYNTHETIC | PRIVATE,
3609                         initName, initBlockType, enclClass);
3610                 initSym.params = List.nil();
3611                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(initSym)));
3612             } else {
3613                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3614             }
3615             lambdaEnv.info.yieldResult = null;
3616             lambdaEnv.info.isLambda = true;
3617             return lambdaEnv;
3618         }
3619 
3620     @Override
3621     public void visitReference(final JCMemberReference that) {
3622         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3623             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3624                 //method reference only allowed in assignment or method invocation/cast context
3625                 log.error(that.pos(), Errors.UnexpectedMref);
3626             }
3627             result = that.type = types.createErrorType(pt());
3628             return;
3629         }
3630         final Env<AttrContext> localEnv = env.dup(that);
3631         try {
3632             //attribute member reference qualifier - if this is a constructor
3633             //reference, the expected kind must be a type
3634             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3635 
3636             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3637                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3638                 if (!exprType.isErroneous() &&
3639                     exprType.isRaw() &&
3640                     that.typeargs != null) {
3641                     log.error(that.expr.pos(),
3642                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3643                                                  Fragments.MrefInferAndExplicitParams));
3644                     exprType = types.createErrorType(exprType);
3645                 }
3646             }
3647 
3648             if (exprType.isErroneous()) {
3649                 //if the qualifier expression contains problems,
3650                 //give up attribution of method reference
3651                 result = that.type = exprType;
3652                 return;
3653             }
3654 
3655             if (TreeInfo.isStaticSelector(that.expr, names)) {
3656                 //if the qualifier is a type, validate it; raw warning check is
3657                 //omitted as we don't know at this stage as to whether this is a
3658                 //raw selector (because of inference)
3659                 chk.validate(that.expr, env, false);
3660             } else {
3661                 Symbol lhsSym = TreeInfo.symbol(that.expr);
3662                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
3663             }
3664             //attrib type-arguments
3665             List<Type> typeargtypes = List.nil();
3666             if (that.typeargs != null) {
3667                 typeargtypes = attribTypes(that.typeargs, localEnv);
3668             }
3669 
3670             boolean isTargetSerializable =
3671                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3672                     rs.isSerializable(pt());
3673             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
3674             Type currentTarget = targetInfo.target;
3675             Type desc = targetInfo.descriptor;
3676 
3677             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
3678             List<Type> argtypes = desc.getParameterTypes();
3679             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
3680 
3681             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
3682                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
3683             }
3684 
3685             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
3686             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
3687             try {
3688                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
3689                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
3690                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
3691             } finally {
3692                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
3693             }
3694 
3695             Symbol refSym = refResult.fst;
3696             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
3697 
3698             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
3699              *  JDK-8075541
3700              */
3701             if (refSym.kind != MTH) {
3702                 boolean targetError;
3703                 switch (refSym.kind) {
3704                     case ABSENT_MTH:
3705                         targetError = false;
3706                         break;
3707                     case WRONG_MTH:
3708                     case WRONG_MTHS:
3709                     case AMBIGUOUS:
3710                     case HIDDEN:
3711                     case STATICERR:
3712                         targetError = true;
3713                         break;
3714                     default:
3715                         Assert.error("unexpected result kind " + refSym.kind);
3716                         targetError = false;
3717                 }
3718 
3719                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
3720                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
3721                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
3722 
3723                 JCDiagnostic diag = diags.create(log.currentSource(), that,
3724                         targetError ?
3725                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
3726                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
3727 
3728                 if (targetError && currentTarget == Type.recoveryType) {
3729                     //a target error doesn't make sense during recovery stage
3730                     //as we don't know what actual parameter types are
3731                     result = that.type = currentTarget;
3732                     return;
3733                 } else {
3734                     if (targetError) {
3735                         resultInfo.checkContext.report(that, diag);
3736                     } else {
3737                         log.report(diag);
3738                     }
3739                     result = that.type = types.createErrorType(currentTarget);
3740                     return;
3741                 }
3742             }
3743 
3744             that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
3745             that.kind = lookupHelper.referenceKind(that.sym);
3746             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
3747 
3748             if (desc.getReturnType() == Type.recoveryType) {
3749                 // stop here
3750                 result = that.type = currentTarget;
3751                 return;
3752             }
3753 
3754             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3755                 checkNewInnerClass(that.pos(), env, exprType, false);
3756             }
3757 
3758             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3759 
3760                 if (that.getMode() == ReferenceMode.INVOKE &&
3761                         TreeInfo.isStaticSelector(that.expr, names) &&
3762                         that.kind.isUnbound() &&
3763                         lookupHelper.site.isRaw()) {
3764                     chk.checkRaw(that.expr, localEnv);
3765                 }
3766 
3767                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
3768                         exprType.getTypeArguments().nonEmpty()) {
3769                     //static ref with class type-args
3770                     log.error(that.expr.pos(),
3771                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3772                                                  Fragments.StaticMrefWithTargs));
3773                     result = that.type = types.createErrorType(currentTarget);
3774                     return;
3775                 }
3776 
3777                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
3778                     // Check that super-qualified symbols are not abstract (JLS)
3779                     rs.checkNonAbstract(that.pos(), that.sym);
3780                 }
3781 
3782                 if (isTargetSerializable) {
3783                     chk.checkAccessFromSerializableElement(that, true);
3784                 }
3785             }
3786 
3787             ResultInfo checkInfo =
3788                     resultInfo.dup(newMethodTemplate(
3789                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
3790                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
3791                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3792 
3793             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
3794 
3795             if (that.kind.isUnbound() &&
3796                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
3797                 //re-generate inference constraints for unbound receiver
3798                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
3799                     //cannot happen as this has already been checked - we just need
3800                     //to regenerate the inference constraints, as that has been lost
3801                     //as a result of the call to inferenceContext.save()
3802                     Assert.error("Can't get here");
3803                 }
3804             }
3805 
3806             if (!refType.isErroneous()) {
3807                 refType = types.createMethodTypeWithReturn(refType,
3808                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
3809             }
3810 
3811             //go ahead with standard method reference compatibility check - note that param check
3812             //is a no-op (as this has been taken care during method applicability)
3813             boolean isSpeculativeRound =
3814                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3815 
3816             that.type = currentTarget; //avoids recovery at this stage
3817             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
3818             if (!isSpeculativeRound) {
3819                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
3820             }
3821             chk.checkRequiresIdentity(that, localEnv.info.lint);
3822             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3823         } catch (Types.FunctionDescriptorLookupError ex) {
3824             JCDiagnostic cause = ex.getDiagnostic();
3825             resultInfo.checkContext.report(that, cause);
3826             result = that.type = types.createErrorType(pt());
3827             return;
3828         }
3829     }
3830     //where
3831         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
3832             //if this is a constructor reference, the expected kind must be a type
3833             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
3834                                   KindSelector.VAL_TYP : KindSelector.TYP,
3835                                   Type.noType);
3836         }
3837 
3838 
3839     @SuppressWarnings("fallthrough")
3840     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
3841         InferenceContext inferenceContext = checkContext.inferenceContext();
3842         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
3843 
3844         Type resType;
3845         switch (tree.getMode()) {
3846             case NEW:
3847                 if (!tree.expr.type.isRaw()) {
3848                     resType = tree.expr.type;
3849                     break;
3850                 }
3851             default:
3852                 resType = refType.getReturnType();
3853         }
3854 
3855         Type incompatibleReturnType = resType;
3856 
3857         if (returnType.hasTag(VOID)) {
3858             incompatibleReturnType = null;
3859         }
3860 
3861         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
3862             Type capturedResType = captureMRefReturnType ? types.capture(resType) : resType;
3863             if (resType.isErroneous() ||
3864                     new FunctionalReturnContext(checkContext).compatible(capturedResType, returnType,
3865                             checkContext.checkWarner(tree, capturedResType, returnType))) {
3866                 incompatibleReturnType = null;
3867             }
3868         }
3869 
3870         if (incompatibleReturnType != null) {
3871             Fragment msg =
3872                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
3873             checkContext.report(tree, diags.fragment(msg));
3874         } else {
3875             if (inferenceContext.free(refType)) {
3876                 // we need to wait for inference to finish and then replace inference vars in the referent type
3877                 inferenceContext.addFreeTypeListener(List.of(refType),
3878                         instantiatedContext -> {
3879                             tree.referentType = instantiatedContext.asInstType(refType);
3880                         });
3881             } else {
3882                 tree.referentType = refType;
3883             }
3884         }
3885 
3886         if (!speculativeAttr) {
3887             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
3888                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
3889             }
3890         }
3891     }
3892 
3893     boolean checkExConstraints(
3894             List<Type> thrownByFuncExpr,
3895             List<Type> thrownAtFuncType,
3896             InferenceContext inferenceContext) {
3897         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
3898          *  are not proper types
3899          */
3900         List<Type> nonProperList = thrownAtFuncType.stream()
3901                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
3902         List<Type> properList = thrownAtFuncType.diff(nonProperList);
3903 
3904         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
3905          *  in the throws clause of the invocation type of the method reference's compile-time
3906          *  declaration
3907          */
3908         List<Type> checkedList = thrownByFuncExpr.stream()
3909                 .filter(e -> chk.isChecked(e)).collect(List.collector());
3910 
3911         /** If n = 0 (the function type's throws clause consists only of proper types), then
3912          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
3913          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
3914          *  reduces to true
3915          */
3916         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
3917         for (Type checked : checkedList) {
3918             boolean isSubtype = false;
3919             for (Type proper : properList) {
3920                 if (types.isSubtype(checked, proper)) {
3921                     isSubtype = true;
3922                     break;
3923                 }
3924             }
3925             if (!isSubtype) {
3926                 uncaughtByProperTypes.add(checked);
3927             }
3928         }
3929 
3930         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
3931             return false;
3932         }
3933 
3934         /** If n > 0, the constraint reduces to a set of subtyping constraints:
3935          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
3936          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
3937          */
3938         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
3939         uncaughtByProperTypes.forEach(checkedEx -> {
3940             nonProperAsUndet.forEach(nonProper -> {
3941                 types.isSubtype(checkedEx, nonProper);
3942             });
3943         });
3944 
3945         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
3946          */
3947         nonProperAsUndet.stream()
3948                 .filter(t -> t.hasTag(UNDETVAR))
3949                 .forEach(t -> ((UndetVar)t).setThrow());
3950         return true;
3951     }
3952 
3953     /**
3954      * Set functional type info on the underlying AST. Note: as the target descriptor
3955      * might contain inference variables, we might need to register an hook in the
3956      * current inference context.
3957      */
3958     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
3959             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
3960         if (checkContext.inferenceContext().free(descriptorType)) {
3961             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
3962                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
3963                     inferenceContext.asInstType(primaryTarget), checkContext));
3964         } else {
3965             fExpr.owner = env.info.scope.owner;
3966             if (pt.hasTag(CLASS)) {
3967                 fExpr.target = primaryTarget;
3968             }
3969             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3970                     pt != Type.recoveryType) {
3971                 //check that functional interface class is well-formed
3972                 try {
3973                     /* Types.makeFunctionalInterfaceClass() may throw an exception
3974                      * when it's executed post-inference. See the listener code
3975                      * above.
3976                      */
3977                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
3978                             names.empty, fExpr.target, ABSTRACT);
3979                     if (csym != null) {
3980                         chk.checkImplementations(env.tree, csym, csym);
3981                         try {
3982                             //perform an additional functional interface check on the synthetic class,
3983                             //as there may be spurious errors for raw targets - because of existing issues
3984                             //with membership and inheritance (see JDK-8074570).
3985                             csym.flags_field |= INTERFACE;
3986                             types.findDescriptorType(csym.type);
3987                         } catch (FunctionDescriptorLookupError err) {
3988                             resultInfo.checkContext.report(fExpr,
3989                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
3990                         }
3991                     }
3992                 } catch (Types.FunctionDescriptorLookupError ex) {
3993                     JCDiagnostic cause = ex.getDiagnostic();
3994                     resultInfo.checkContext.report(env.tree, cause);
3995                 }
3996             }
3997         }
3998     }
3999 
4000     public void visitParens(JCParens tree) {
4001         Type owntype = attribTree(tree.expr, env, resultInfo);
4002         result = check(tree, owntype, pkind(), resultInfo);
4003         Symbol sym = TreeInfo.symbol(tree);
4004         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
4005             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
4006     }
4007 
4008     public void visitAssign(JCAssign tree) {
4009         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
4010         Type capturedType = capture(owntype);
4011         attribExpr(tree.rhs, env, owntype);
4012         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
4013     }
4014 
4015     public void visitAssignop(JCAssignOp tree) {
4016         // Attribute arguments.
4017         Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
4018         Type operand = attribExpr(tree.rhs, env);
4019         // Find operator.
4020         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
4021         if (operator != operators.noOpSymbol &&
4022                 !owntype.isErroneous() &&
4023                 !operand.isErroneous()) {
4024             chk.checkDivZero(tree.rhs.pos(), operator, operand);
4025             chk.checkCastable(tree.rhs.pos(),
4026                               operator.type.getReturnType(),
4027                               owntype);
4028             switch (tree.getTag()) {
4029             case SL_ASG, SR_ASG, USR_ASG -> { }     // we only use (at most) the lower 6 bits, so any integral type is OK
4030             default -> chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
4031             }
4032             chk.checkOutOfRangeShift(tree.rhs.pos(), operator, operand);
4033         }
4034         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4035     }
4036 
4037     public void visitUnary(JCUnary tree) {
4038         // Attribute arguments.
4039         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
4040             ? attribTree(tree.arg, env, varAssignmentInfo)
4041             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
4042 
4043         // Find operator.
4044         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
4045         Type owntype = types.createErrorType(tree.type);
4046         if (operator != operators.noOpSymbol &&
4047                 !argtype.isErroneous()) {
4048             owntype = (tree.getTag().isIncOrDecUnaryOp())
4049                 ? tree.arg.type
4050                 : operator.type.getReturnType();
4051             int opc = operator.opcode;
4052 
4053             // If the argument is constant, fold it.
4054             if (argtype.constValue() != null) {
4055                 Type ctype = cfolder.fold1(opc, argtype);
4056                 if (ctype != null) {
4057                     owntype = cfolder.coerce(ctype, owntype);
4058                 }
4059             }
4060         }
4061         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4062         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4063     }
4064 
4065     public void visitBinary(JCBinary tree) {
4066         // Attribute arguments.
4067         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4068         // x && y
4069         // include x's bindings when true in y
4070 
4071         // x || y
4072         // include x's bindings when false in y
4073 
4074         MatchBindings lhsBindings = matchBindings;
4075         List<BindingSymbol> propagatedBindings;
4076         switch (tree.getTag()) {
4077             case AND:
4078                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4079                 break;
4080             case OR:
4081                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4082                 break;
4083             default:
4084                 propagatedBindings = List.nil();
4085                 break;
4086         }
4087         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4088         Type right;
4089         try {
4090             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4091         } finally {
4092             rhsEnv.info.scope.leave();
4093         }
4094 
4095         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4096 
4097         // Find operator.
4098         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4099         Type owntype = types.createErrorType(tree.type);
4100         if (operator != operators.noOpSymbol &&
4101                 !left.isErroneous() &&
4102                 !right.isErroneous()) {
4103             owntype = operator.type.getReturnType();
4104             int opc = operator.opcode;
4105             // If both arguments are constants, fold them.
4106             if (left.constValue() != null && right.constValue() != null) {
4107                 Type ctype = cfolder.fold2(opc, left, right);
4108                 if (ctype != null) {
4109                     owntype = cfolder.coerce(ctype, owntype);
4110                 }
4111             }
4112 
4113             // Check that argument types of a reference ==, != are
4114             // castable to each other, (JLS 15.21).  Note: unboxing
4115             // comparisons will not have an acmp* opc at this point.
4116             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4117                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4118                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4119                 }
4120             }
4121 
4122             chk.checkDivZero(tree.rhs.pos(), operator, right);
4123             chk.checkOutOfRangeShift(tree.rhs.pos(), operator, right);
4124         }
4125         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4126     }
4127 
4128     public void visitTypeCast(final JCTypeCast tree) {
4129         Type clazztype = attribType(tree.clazz, env);
4130         chk.validate(tree.clazz, env, false);
4131         chk.checkRequiresIdentity(tree, env.info.lint);
4132         //a fresh environment is required for 292 inference to work properly ---
4133         //see Infer.instantiatePolymorphicSignatureInstance()
4134         Env<AttrContext> localEnv = env.dup(tree);
4135         //should we propagate the target type?
4136         final ResultInfo castInfo;
4137         JCExpression expr = TreeInfo.skipParens(tree.expr);
4138         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4139         if (isPoly) {
4140             //expression is a poly - we need to propagate target type info
4141             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4142                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4143                 @Override
4144                 public boolean compatible(Type found, Type req, Warner warn) {
4145                     return types.isCastable(found, req, warn);
4146                 }
4147             });
4148         } else {
4149             //standalone cast - target-type info is not propagated
4150             castInfo = unknownExprInfo;
4151         }
4152         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4153         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4154         if (exprtype.constValue() != null)
4155             owntype = cfolder.coerce(exprtype, owntype);
4156         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4157         if (!isPoly)
4158             chk.checkRedundantCast(localEnv, tree);
4159     }
4160 
4161     public void visitTypeTest(JCInstanceOf tree) {
4162         Type exprtype = attribExpr(tree.expr, env);
4163         if (exprtype.isPrimitive()) {
4164             preview.checkSourceLevel(tree.expr.pos(), Feature.PRIMITIVE_PATTERNS);
4165         } else {
4166             exprtype = chk.checkNullOrRefType(
4167                     tree.expr.pos(), exprtype);
4168         }
4169         Type clazztype;
4170         JCTree typeTree;
4171         if (tree.pattern.getTag() == BINDINGPATTERN ||
4172             tree.pattern.getTag() == RECORDPATTERN) {
4173             attribExpr(tree.pattern, env, exprtype);
4174             clazztype = tree.pattern.type;
4175             if (types.isSubtype(exprtype, clazztype) &&
4176                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4177                 tree.pattern.getTag() != RECORDPATTERN) {
4178                 if (!allowUnconditionalPatternsInstanceOf) {
4179                     log.error(tree.pos(), Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.error(this.sourceName));
4180                 }
4181             }
4182             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4183         } else {
4184             clazztype = attribType(tree.pattern, env);
4185             typeTree = tree.pattern;
4186             chk.validate(typeTree, env, false);
4187         }
4188         if (clazztype.isPrimitive()) {
4189             preview.checkSourceLevel(tree.pattern.pos(), Feature.PRIMITIVE_PATTERNS);
4190         } else {
4191             if (!clazztype.hasTag(TYPEVAR)) {
4192                 clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4193             }
4194             if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4195                 boolean valid = false;
4196                 if (allowReifiableTypesInInstanceof) {
4197                     valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4198                 } else {
4199                     log.error(tree.pos(), Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4200                     allowReifiableTypesInInstanceof = true;
4201                 }
4202                 if (!valid) {
4203                     clazztype = types.createErrorType(clazztype);
4204                 }
4205             }
4206         }
4207         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4208         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4209     }
4210 
4211     private boolean checkCastablePattern(DiagnosticPosition pos,
4212                                          Type exprType,
4213                                          Type pattType) {
4214         Warner warner = new Warner();
4215         // if any type is erroneous, the problem is reported elsewhere
4216         if (exprType.isErroneous() || pattType.isErroneous()) {
4217             return false;
4218         }
4219         if (!types.isCastable(exprType, pattType, warner)) {
4220             chk.basicHandler.report(pos,
4221                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4222             return false;
4223         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4224                 (!exprType.isPrimitive() || !pattType.isPrimitive() || !types.isSameType(exprType, pattType))) {
4225             preview.checkSourceLevel(pos, Feature.PRIMITIVE_PATTERNS);
4226             return true;
4227         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4228             log.error(pos,
4229                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4230             return false;
4231         } else {
4232             return true;
4233         }
4234     }
4235 
4236     @Override
4237     public void visitAnyPattern(JCAnyPattern tree) {
4238         result = tree.type = resultInfo.pt;
4239     }
4240 
4241     public void visitBindingPattern(JCBindingPattern tree) {
4242         Type type;
4243         if (!tree.var.isImplicitlyTyped()) {
4244             type = attribType(tree.var.vartype, env);
4245         } else {
4246             type = resultInfo.pt;
4247         }
4248         BindingSymbol v = new BindingSymbol(tree.var.mods.flags | tree.var.declKind.additionalSymbolFlags,
4249                                             tree.var.name, type, env.info.scope.owner);
4250         v.pos = tree.pos;
4251         tree.var.sym = v;
4252         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4253             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4254         }
4255         if (tree.var.isImplicitlyTyped()) {
4256             setupImplicitlyTypedVariable(tree.var, type == Type.noType ? syms.errType
4257                                                       : type);
4258         }
4259         chk.validate(tree.var.vartype, env, true);
4260         annotate.annotateLater(tree.var.mods.annotations, env, v);
4261         if (!tree.var.isImplicitlyTyped()) {
4262             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v);
4263         }
4264         annotate.flush();
4265         typeAnnotations.organizeTypeAnnotationsSignaturesForLocalVarType(env, tree.var);
4266         result = tree.type = tree.var.type = v.type;
4267         if (v.isUnnamedVariable()) {
4268             matchBindings = MatchBindingsComputer.EMPTY;
4269         } else {
4270             matchBindings = new MatchBindings(List.of(v), List.nil());
4271         }
4272         chk.checkRequiresIdentity(tree, env.info.lint);
4273     }
4274 
4275     @Override
4276     public void visitRecordPattern(JCRecordPattern tree) {
4277         Type site;
4278 
4279         if (tree.deconstructor.hasTag(VARTYPE)) {
4280             log.error(tree.pos(), Errors.DeconstructionPatternVarNotAllowed);
4281             tree.record = syms.errSymbol;
4282             site = tree.type = types.createErrorType(tree.record.type);
4283         } else {
4284             Type type = attribType(tree.deconstructor, env);
4285             if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4286                 Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4287                 if (inferred == null) {
4288                     log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4289                 } else {
4290                     type = inferred;
4291                 }
4292             }
4293             tree.type = tree.deconstructor.type = type;
4294             site = types.capture(tree.type);
4295             chk.validate(tree.deconstructor, env, true);
4296         }
4297 
4298         List<Type> expectedRecordTypes;
4299         if (site.tsym instanceof ClassSymbol clazz && clazz.isRecord()) {
4300             ClassSymbol record = (ClassSymbol) site.tsym;
4301             expectedRecordTypes = record.getRecordComponents()
4302                                         .stream()
4303                                         .map(rc -> types.memberType(site, rc))
4304                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4305                                         .collect(List.collector());
4306             tree.record = record;
4307         } else {
4308             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4309             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4310                                 .limit(tree.nested.size())
4311                                 .collect(List.collector());
4312             tree.record = syms.errSymbol;
4313         }
4314         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4315         List<Type> recordTypes = expectedRecordTypes;
4316         List<JCPattern> nestedPatterns = tree.nested;
4317         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4318         try {
4319             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4320                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4321                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4322                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4323                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4324                 nestedPatterns = nestedPatterns.tail;
4325                 recordTypes = recordTypes.tail;
4326             }
4327             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4328                 while (nestedPatterns.nonEmpty()) {
4329                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4330                     nestedPatterns = nestedPatterns.tail;
4331                 }
4332                 List<Type> nestedTypes =
4333                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4334                 log.error(tree.pos(),
4335                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4336                                                                  nestedTypes));
4337             }
4338         } finally {
4339             localEnv.info.scope.leave();
4340         }
4341         result = tree.type;
4342         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4343     }
4344 
4345     public void visitIndexed(JCArrayAccess tree) {
4346         Type owntype = types.createErrorType(tree.type);
4347         Type atype = attribExpr(tree.indexed, env);
4348         attribExpr(tree.index, env, syms.intType);
4349         if (types.isArray(atype))
4350             owntype = types.elemtype(atype);
4351         else if (!atype.hasTag(ERROR))
4352             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4353         if (!pkind().contains(KindSelector.VAL))
4354             owntype = capture(owntype);
4355         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4356     }
4357 
4358     public void visitIdent(JCIdent tree) {
4359         Symbol sym;
4360 
4361         // Find symbol
4362         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4363             // If we are looking for a method, the prototype `pt' will be a
4364             // method type with the type of the call's arguments as parameters.
4365             env.info.pendingResolutionPhase = null;
4366             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4367         } else if (tree.sym != null && tree.sym.kind != VAR) {
4368             sym = tree.sym;
4369         } else {
4370             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4371         }
4372         tree.sym = sym;
4373 
4374         // Also find the environment current for the class where
4375         // sym is defined (`symEnv').
4376         Env<AttrContext> symEnv = env;
4377         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4378             sym.kind.matches(KindSelector.VAL_MTH) &&
4379             sym.owner.kind == TYP &&
4380             tree.name != names._this && tree.name != names._super) {
4381 
4382             // Find environment in which identifier is defined.
4383             while (symEnv.outer != null &&
4384                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4385                 symEnv = symEnv.outer;
4386             }
4387         }
4388 
4389         // If symbol is a variable, ...
4390         if (sym.kind == VAR) {
4391             VarSymbol v = (VarSymbol)sym;
4392 
4393             // ..., evaluate its initializer, if it has one, and check for
4394             // illegal forward reference.
4395             checkInit(tree, env, v, false);
4396 
4397             // If we are expecting a variable (as opposed to a value), check
4398             // that the variable is assignable in the current environment.
4399             if (KindSelector.ASG.subset(pkind()))
4400                 checkAssignable(tree.pos(), v, null, env);
4401         }
4402 
4403         Env<AttrContext> env1 = env;
4404         if (sym.kind != ERR && sym.kind != TYP &&
4405             sym.owner != null && sym.owner != env1.enclClass.sym) {
4406             // If the found symbol is inaccessible, then it is
4407             // accessed through an enclosing instance.  Locate this
4408             // enclosing instance:
4409             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4410                 env1 = env1.outer;
4411         }
4412 
4413         if (env.info.isSerializable) {
4414             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4415         }
4416 
4417         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4418     }
4419 
4420     public void visitSelect(JCFieldAccess tree) {
4421         // Determine the expected kind of the qualifier expression.
4422         KindSelector skind = KindSelector.NIL;
4423         if (tree.name == names._this || tree.name == names._super ||
4424                 tree.name == names._class)
4425         {
4426             skind = KindSelector.TYP;
4427         } else {
4428             if (pkind().contains(KindSelector.PCK))
4429                 skind = KindSelector.of(skind, KindSelector.PCK);
4430             if (pkind().contains(KindSelector.TYP))
4431                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4432             if (pkind().contains(KindSelector.VAL_MTH))
4433                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4434         }
4435 
4436         // Attribute the qualifier expression, and determine its symbol (if any).
4437         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
4438         if (!pkind().contains(KindSelector.TYP_PCK))
4439             site = capture(site); // Capture field access
4440 
4441         // don't allow T.class T[].class, etc
4442         if (skind == KindSelector.TYP) {
4443             Type elt = site;
4444             while (elt.hasTag(ARRAY))
4445                 elt = ((ArrayType)elt).elemtype;
4446             if (elt.hasTag(TYPEVAR)) {
4447                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4448                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4449                 tree.sym = tree.type.tsym;
4450                 return ;
4451             }
4452         }
4453 
4454         // If qualifier symbol is a type or `super', assert `selectSuper'
4455         // for the selection. This is relevant for determining whether
4456         // protected symbols are accessible.
4457         Symbol sitesym = TreeInfo.symbol(tree.selected);
4458         boolean selectSuperPrev = env.info.selectSuper;
4459         env.info.selectSuper =
4460             sitesym != null &&
4461             sitesym.name == names._super;
4462 
4463         // Determine the symbol represented by the selection.
4464         env.info.pendingResolutionPhase = null;
4465         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
4466         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4467             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4468             sym = syms.errSymbol;
4469         }
4470         if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
4471             site = capture(site);
4472             sym = selectSym(tree, sitesym, site, env, resultInfo);
4473         }
4474         boolean varArgs = env.info.lastResolveVarargs();
4475         tree.sym = sym;
4476 
4477         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4478             site = types.skipTypeVars(site, true);
4479         }
4480 
4481         // If that symbol is a variable, ...
4482         if (sym.kind == VAR) {
4483             VarSymbol v = (VarSymbol)sym;
4484 
4485             // ..., evaluate its initializer, if it has one, and check for
4486             // illegal forward reference.
4487             checkInit(tree, env, v, true);
4488 
4489             // If we are expecting a variable (as opposed to a value), check
4490             // that the variable is assignable in the current environment.
4491             if (KindSelector.ASG.subset(pkind()))
4492                 checkAssignable(tree.pos(), v, tree.selected, env);
4493         }
4494 
4495         if (sitesym != null &&
4496                 sitesym.kind == VAR &&
4497                 ((VarSymbol)sitesym).isResourceVariable() &&
4498                 sym.kind == MTH &&
4499                 sym.name.equals(names.close) &&
4500                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true)) {
4501             log.warning(tree, LintWarnings.TryExplicitCloseCall);
4502         }
4503 
4504         // Disallow selecting a type from an expression
4505         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4506             tree.type = check(tree.selected, pt(),
4507                               sitesym == null ?
4508                                       KindSelector.VAL : sitesym.kind.toSelector(),
4509                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4510         }
4511 
4512         if (isType(sitesym)) {
4513             if (sym.name != names._this && sym.name != names._super) {
4514                 // Check if type-qualified fields or methods are static (JLS)
4515                 if ((sym.flags() & STATIC) == 0 &&
4516                     sym.name != names._super &&
4517                     (sym.kind == VAR || sym.kind == MTH)) {
4518                     rs.accessBase(rs.new StaticError(sym),
4519                               tree.pos(), site, sym.name, true);
4520                 }
4521             }
4522         } else if (sym.kind != ERR &&
4523                    (sym.flags() & STATIC) != 0 &&
4524                    sym.name != names._class) {
4525             // If the qualified item is not a type and the selected item is static, report
4526             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4527             if (!sym.owner.isAnonymous()) {
4528                 log.warning(tree, LintWarnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4529             } else {
4530                 log.warning(tree, LintWarnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4531             }
4532         }
4533 
4534         // If we are selecting an instance member via a `super', ...
4535         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4536 
4537             // Check that super-qualified symbols are not abstract (JLS)
4538             rs.checkNonAbstract(tree.pos(), sym);
4539 
4540             if (site.isRaw()) {
4541                 // Determine argument types for site.
4542                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
4543                 if (site1 != null) site = site1;
4544             }
4545         }
4546 
4547         if (env.info.isSerializable) {
4548             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4549         }
4550 
4551         env.info.selectSuper = selectSuperPrev;
4552         result = checkId(tree, site, sym, env, resultInfo);
4553     }
4554     //where
4555         /** Determine symbol referenced by a Select expression,
4556          *
4557          *  @param tree   The select tree.
4558          *  @param site   The type of the selected expression,
4559          *  @param env    The current environment.
4560          *  @param resultInfo The current result.
4561          */
4562         private Symbol selectSym(JCFieldAccess tree,
4563                                  Symbol location,
4564                                  Type site,
4565                                  Env<AttrContext> env,
4566                                  ResultInfo resultInfo) {
4567             DiagnosticPosition pos = tree.pos();
4568             Name name = tree.name;
4569             switch (site.getTag()) {
4570             case PACKAGE:
4571                 return rs.accessBase(
4572                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4573                     pos, location, site, name, true);
4574             case ARRAY:
4575             case CLASS:
4576                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4577                     return rs.resolveQualifiedMethod(
4578                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4579                 } else if (name == names._this || name == names._super) {
4580                     return rs.resolveSelf(pos, env, site.tsym, tree);
4581                 } else if (name == names._class) {
4582                     // In this case, we have already made sure in
4583                     // visitSelect that qualifier expression is a type.
4584                     return syms.getClassField(site, types);
4585                 } else {
4586                     // We are seeing a plain identifier as selector.
4587                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
4588                         sym = rs.accessBase(sym, pos, location, site, name, true);
4589                     return sym;
4590                 }
4591             case WILDCARD:
4592                 throw new AssertionError(tree);
4593             case TYPEVAR:
4594                 // Normally, site.getUpperBound() shouldn't be null.
4595                 // It should only happen during memberEnter/attribBase
4596                 // when determining the supertype which *must* be
4597                 // done before attributing the type variables.  In
4598                 // other words, we are seeing this illegal program:
4599                 // class B<T> extends A<T.foo> {}
4600                 Symbol sym = (site.getUpperBound() != null)
4601                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
4602                     : null;
4603                 if (sym == null) {
4604                     log.error(pos, Errors.TypeVarCantBeDeref);
4605                     return syms.errSymbol;
4606                 } else {
4607                     // JLS 4.9 specifies the members are derived by inheritance.
4608                     // We skip inducing a whole class by filtering members that
4609                     // can never be inherited:
4610                     Symbol sym2;
4611                     if (sym.isPrivate()) {
4612                         // Private members
4613                         sym2 = rs.new AccessError(env, site, sym);
4614                     } else if (sym.owner.isInterface() && sym.kind == MTH && (sym.flags() & STATIC) != 0) {
4615                         // Interface static methods
4616                         sym2 = rs.new SymbolNotFoundError(ABSENT_MTH);
4617                     } else {
4618                         sym2 = sym;
4619                     }
4620                     rs.accessBase(sym2, pos, location, site, name, true);
4621                     return sym;
4622                 }
4623             case ERROR:
4624                 // preserve identifier names through errors
4625                 return types.createErrorType(name, site.tsym, site).tsym;
4626             default:
4627                 // The qualifier expression is of a primitive type -- only
4628                 // .class is allowed for these.
4629                 if (name == names._class) {
4630                     // In this case, we have already made sure in Select that
4631                     // qualifier expression is a type.
4632                     return syms.getClassField(site, types);
4633                 } else {
4634                     log.error(pos, Errors.CantDeref(site));
4635                     return syms.errSymbol;
4636                 }
4637             }
4638         }
4639 
4640         /** Determine type of identifier or select expression and check that
4641          *  (1) the referenced symbol is not deprecated
4642          *  (2) the symbol's type is safe (@see checkSafe)
4643          *  (3) if symbol is a variable, check that its type and kind are
4644          *      compatible with the prototype and protokind.
4645          *  (4) if symbol is an instance field of a raw type,
4646          *      which is being assigned to, issue an unchecked warning if its
4647          *      type changes under erasure.
4648          *  (5) if symbol is an instance method of a raw type, issue an
4649          *      unchecked warning if its argument types change under erasure.
4650          *  If checks succeed:
4651          *    If symbol is a constant, return its constant type
4652          *    else if symbol is a method, return its result type
4653          *    otherwise return its type.
4654          *  Otherwise return errType.
4655          *
4656          *  @param tree       The syntax tree representing the identifier
4657          *  @param site       If this is a select, the type of the selected
4658          *                    expression, otherwise the type of the current class.
4659          *  @param sym        The symbol representing the identifier.
4660          *  @param env        The current environment.
4661          *  @param resultInfo    The expected result
4662          */
4663         Type checkId(JCTree tree,
4664                      Type site,
4665                      Symbol sym,
4666                      Env<AttrContext> env,
4667                      ResultInfo resultInfo) {
4668             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
4669                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
4670                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4671         }
4672 
4673         Type checkMethodIdInternal(JCTree tree,
4674                      Type site,
4675                      Symbol sym,
4676                      Env<AttrContext> env,
4677                      ResultInfo resultInfo) {
4678             if (resultInfo.pkind.contains(KindSelector.POLY)) {
4679                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
4680             } else {
4681                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4682             }
4683         }
4684 
4685         Type checkIdInternal(JCTree tree,
4686                      Type site,
4687                      Symbol sym,
4688                      Type pt,
4689                      Env<AttrContext> env,
4690                      ResultInfo resultInfo) {
4691             Type owntype; // The computed type of this identifier occurrence.
4692             switch (sym.kind) {
4693             case TYP:
4694                 // For types, the computed type equals the symbol's type,
4695                 // except for two situations:
4696                 owntype = sym.type;
4697                 if (owntype.hasTag(CLASS)) {
4698                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
4699                     Type ownOuter = owntype.getEnclosingType();
4700 
4701                     // (a) If the symbol's type is parameterized, erase it
4702                     // because no type parameters were given.
4703                     // We recover generic outer type later in visitTypeApply.
4704                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
4705                         owntype = types.erasure(owntype);
4706                     }
4707 
4708                     // (b) If the symbol's type is an inner class, then
4709                     // we have to interpret its outer type as a superclass
4710                     // of the site type. Example:
4711                     //
4712                     // class Tree<A> { class Visitor { ... } }
4713                     // class PointTree extends Tree<Point> { ... }
4714                     // ...PointTree.Visitor...
4715                     //
4716                     // Then the type of the last expression above is
4717                     // Tree<Point>.Visitor.
4718                     else if ((ownOuter.hasTag(CLASS) || ownOuter.hasTag(TYPEVAR)) && site != ownOuter) {
4719                         Type normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
4720                         if (normOuter == null) // perhaps from an import
4721                             normOuter = types.erasure(ownOuter);
4722                         if (normOuter != ownOuter)
4723                             owntype = new ClassType(
4724                                 normOuter, List.nil(), owntype.tsym,
4725                                 owntype.getMetadata());
4726                     }
4727                 }
4728                 break;
4729             case VAR:
4730                 VarSymbol v = (VarSymbol)sym;
4731 
4732                 if (env.info.enclVar != null
4733                         && v.type.hasTag(NONE)) {
4734                     //self reference to implicitly typed variable declaration
4735                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
4736                     return tree.type = v.type = types.createErrorType(v.type);
4737                 }
4738 
4739                 // Test (4): if symbol is an instance field of a raw type,
4740                 // which is being assigned to, issue an unchecked warning if
4741                 // its type changes under erasure.
4742                 if (KindSelector.ASG.subset(pkind()) &&
4743                     v.owner.kind == TYP &&
4744                     (v.flags() & STATIC) == 0 &&
4745                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4746                     Type s = types.asOuterSuper(site, v.owner);
4747                     if (s != null &&
4748                         s.isRaw() &&
4749                         !types.isSameType(v.type, v.erasure(types))) {
4750                         chk.warnUnchecked(tree.pos(), LintWarnings.UncheckedAssignToVar(v, s));
4751                     }
4752                 }
4753                 // The computed type of a variable is the type of the
4754                 // variable symbol, taken as a member of the site type.
4755                 owntype = (sym.owner.kind == TYP &&
4756                            sym.name != names._this && sym.name != names._super)
4757                     ? types.memberType(site, sym)
4758                     : sym.type;
4759 
4760                 // If the variable is a constant, record constant value in
4761                 // computed type.
4762                 if (v.getConstValue() != null && isStaticReference(tree))
4763                     owntype = owntype.constType(v.getConstValue());
4764 
4765                 if (resultInfo.pkind == KindSelector.VAL) {
4766                     owntype = capture(owntype); // capture "names as expressions"
4767                 }
4768                 break;
4769             case MTH: {
4770                 owntype = checkMethod(site, sym,
4771                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
4772                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
4773                         resultInfo.pt.getTypeArguments());
4774                 chk.checkRestricted(tree.pos(), sym);
4775                 break;
4776             }
4777             case PCK: case ERR:
4778                 owntype = sym.type;
4779                 break;
4780             default:
4781                 throw new AssertionError("unexpected kind: " + sym.kind +
4782                                          " in tree " + tree);
4783             }
4784 
4785             // Emit a `deprecation' warning if symbol is deprecated.
4786             // (for constructors (but not for constructor references), the error
4787             // was given when the constructor was resolved)
4788 
4789             if (sym.name != names.init || tree.hasTag(REFERENCE)) {
4790                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
4791                 chk.checkSunAPI(tree.pos(), sym);
4792                 chk.checkProfile(tree.pos(), sym);
4793                 chk.checkPreview(tree.pos(), env.info.scope.owner, site, sym);
4794             }
4795 
4796             if (pt.isErroneous()) {
4797                 owntype = types.createErrorType(owntype);
4798             }
4799 
4800             // If symbol is a variable, check that its type and
4801             // kind are compatible with the prototype and protokind.
4802             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
4803         }
4804 
4805         /** Check that variable is initialized and evaluate the variable's
4806          *  initializer, if not yet done. Also check that variable is not
4807          *  referenced before it is defined.
4808          *  @param tree    The tree making up the variable reference.
4809          *  @param env     The current environment.
4810          *  @param v       The variable's symbol.
4811          */
4812         private void checkInit(JCTree tree,
4813                                Env<AttrContext> env,
4814                                VarSymbol v,
4815                                boolean onlyWarning) {
4816             // A forward reference is diagnosed if the declaration position
4817             // of the variable is greater than the current tree position
4818             // and the tree and variable definition occur in the same class
4819             // definition.  Note that writes don't count as references.
4820             // This check applies only to class and instance
4821             // variables.  Local variables follow different scope rules,
4822             // and are subject to definite assignment checking.
4823             Env<AttrContext> initEnv = enclosingInitEnv(env);
4824             if (initEnv != null &&
4825                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
4826                 v.owner.kind == TYP &&
4827                 v.owner == env.info.scope.owner.enclClass() &&
4828                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
4829                 (!env.tree.hasTag(ASSIGN) ||
4830                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
4831                 if (!onlyWarning || isStaticEnumField(v)) {
4832                     Error errkey = (initEnv.info.enclVar == v) ?
4833                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
4834                     log.error(tree.pos(), errkey);
4835                 } else if (useBeforeDeclarationWarning) {
4836                     Warning warnkey = (initEnv.info.enclVar == v) ?
4837                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
4838                     log.warning(tree.pos(), warnkey);
4839                 }
4840             }
4841 
4842             v.getConstValue(); // ensure initializer is evaluated
4843 
4844             checkEnumInitializer(tree, env, v);
4845         }
4846 
4847         /**
4848          * Returns the enclosing init environment associated with this env (if any). An init env
4849          * can be either a field declaration env or a static/instance initializer env.
4850          */
4851         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
4852             while (true) {
4853                 switch (env.tree.getTag()) {
4854                     case VARDEF:
4855                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
4856                         if (vdecl.sym.owner.kind == TYP) {
4857                             //field
4858                             return env;
4859                         }
4860                         break;
4861                     case BLOCK:
4862                         if (env.next.tree.hasTag(CLASSDEF)) {
4863                             //instance/static initializer
4864                             return env;
4865                         }
4866                         break;
4867                     case METHODDEF:
4868                     case CLASSDEF:
4869                     case TOPLEVEL:
4870                         return null;
4871                 }
4872                 Assert.checkNonNull(env.next);
4873                 env = env.next;
4874             }
4875         }
4876 
4877         /**
4878          * Check for illegal references to static members of enum.  In
4879          * an enum type, constructors and initializers may not
4880          * reference its static members unless they are constant.
4881          *
4882          * @param tree    The tree making up the variable reference.
4883          * @param env     The current environment.
4884          * @param v       The variable's symbol.
4885          * @jls 8.9 Enum Types
4886          */
4887         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
4888             // JLS:
4889             //
4890             // "It is a compile-time error to reference a static field
4891             // of an enum type that is not a compile-time constant
4892             // (15.28) from constructors, instance initializer blocks,
4893             // or instance variable initializer expressions of that
4894             // type. It is a compile-time error for the constructors,
4895             // instance initializer blocks, or instance variable
4896             // initializer expressions of an enum constant e to refer
4897             // to itself or to an enum constant of the same type that
4898             // is declared to the right of e."
4899             if (isStaticEnumField(v)) {
4900                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
4901 
4902                 if (enclClass == null || enclClass.owner == null)
4903                     return;
4904 
4905                 // See if the enclosing class is the enum (or a
4906                 // subclass thereof) declaring v.  If not, this
4907                 // reference is OK.
4908                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
4909                     return;
4910 
4911                 // If the reference isn't from an initializer, then
4912                 // the reference is OK.
4913                 if (!Resolve.isInitializer(env))
4914                     return;
4915 
4916                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
4917             }
4918         }
4919 
4920         /** Is the given symbol a static, non-constant field of an Enum?
4921          *  Note: enum literals should not be regarded as such
4922          */
4923         private boolean isStaticEnumField(VarSymbol v) {
4924             return Flags.isEnum(v.owner) &&
4925                    Flags.isStatic(v) &&
4926                    !Flags.isConstant(v) &&
4927                    v.name != names._class;
4928         }
4929 
4930     /**
4931      * Check that method arguments conform to its instantiation.
4932      **/
4933     public Type checkMethod(Type site,
4934                             final Symbol sym,
4935                             ResultInfo resultInfo,
4936                             Env<AttrContext> env,
4937                             final List<JCExpression> argtrees,
4938                             List<Type> argtypes,
4939                             List<Type> typeargtypes) {
4940         // Test (5): if symbol is an instance method of a raw type, issue
4941         // an unchecked warning if its argument types change under erasure.
4942         if ((sym.flags() & STATIC) == 0 &&
4943             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4944             Type s = types.asOuterSuper(site, sym.owner);
4945             if (s != null && s.isRaw() &&
4946                 !types.isSameTypes(sym.type.getParameterTypes(),
4947                                    sym.erasure(types).getParameterTypes())) {
4948                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedCallMbrOfRawType(sym, s));
4949             }
4950         }
4951 
4952         if (env.info.defaultSuperCallSite != null) {
4953             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
4954                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
4955                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
4956                 List<MethodSymbol> icand_sup =
4957                         types.interfaceCandidates(sup, (MethodSymbol)sym);
4958                 if (icand_sup.nonEmpty() &&
4959                         icand_sup.head != sym &&
4960                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
4961                     log.error(env.tree.pos(),
4962                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
4963                     break;
4964                 }
4965             }
4966             env.info.defaultSuperCallSite = null;
4967         }
4968 
4969         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
4970             JCMethodInvocation app = (JCMethodInvocation)env.tree;
4971             if (app.meth.hasTag(SELECT) &&
4972                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
4973                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
4974             }
4975         }
4976 
4977         // Compute the identifier's instantiated type.
4978         // For methods, we need to compute the instance type by
4979         // Resolve.instantiate from the symbol's type as well as
4980         // any type arguments and value arguments.
4981         Warner noteWarner = new Warner();
4982         try {
4983             Type owntype = rs.checkMethod(
4984                     env,
4985                     site,
4986                     sym,
4987                     resultInfo,
4988                     argtypes,
4989                     typeargtypes,
4990                     noteWarner);
4991 
4992             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
4993                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
4994 
4995             argtypes = argtypes.map(checkDeferredMap);
4996 
4997             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
4998                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedMethInvocationApplied(kindName(sym),
4999                         sym.name,
5000                         rs.methodArguments(sym.type.getParameterTypes()),
5001                         rs.methodArguments(argtypes.map(checkDeferredMap)),
5002                         kindName(sym.location()),
5003                         sym.location()));
5004                 if (resultInfo.pt != Infer.anyPoly ||
5005                         !owntype.hasTag(METHOD) ||
5006                         !owntype.isPartial()) {
5007                     //if this is not a partially inferred method type, erase return type. Otherwise,
5008                     //erasure is carried out in PartiallyInferredMethodType.check().
5009                     owntype = new MethodType(owntype.getParameterTypes(),
5010                             types.erasure(owntype.getReturnType()),
5011                             types.erasure(owntype.getThrownTypes()),
5012                             syms.methodClass);
5013                 }
5014             }
5015 
5016             PolyKind pkind = (sym.type.hasTag(FORALL) &&
5017                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
5018                  PolyKind.POLY : PolyKind.STANDALONE;
5019             TreeInfo.setPolyKind(env.tree, pkind);
5020 
5021             return (resultInfo.pt == Infer.anyPoly) ?
5022                     owntype :
5023                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
5024                             resultInfo.checkContext.inferenceContext());
5025         } catch (Infer.InferenceException ex) {
5026             //invalid target type - propagate exception outwards or report error
5027             //depending on the current check context
5028             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
5029             return types.createErrorType(site);
5030         } catch (Resolve.InapplicableMethodException ex) {
5031             final JCDiagnostic diag = ex.getDiagnostic();
5032             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
5033                 @Override
5034                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
5035                     return new Pair<>(sym, diag);
5036                 }
5037             };
5038             List<Type> argtypes2 = argtypes.map(
5039                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
5040             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
5041                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
5042             log.report(errDiag);
5043             return types.createErrorType(site);
5044         }
5045     }
5046 
5047     public void visitLiteral(JCLiteral tree) {
5048         result = check(tree, litType(tree.typetag).constType(tree.value),
5049                 KindSelector.VAL, resultInfo);
5050     }
5051     //where
5052     /** Return the type of a literal with given type tag.
5053      */
5054     Type litType(TypeTag tag) {
5055         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
5056     }
5057 
5058     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5059         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5060     }
5061 
5062     public void visitTypeArray(JCArrayTypeTree tree) {
5063         Type etype = attribType(tree.elemtype, env);
5064         Type type = new ArrayType(etype, syms.arrayClass);
5065         result = check(tree, type, KindSelector.TYP, resultInfo);
5066     }
5067 
5068     /** Visitor method for parameterized types.
5069      *  Bound checking is left until later, since types are attributed
5070      *  before supertype structure is completely known
5071      */
5072     public void visitTypeApply(JCTypeApply tree) {
5073         Type owntype = types.createErrorType(tree.type);
5074 
5075         // Attribute functor part of application and make sure it's a class.
5076         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5077 
5078         // Attribute type parameters
5079         List<Type> actuals = attribTypes(tree.arguments, env);
5080 
5081         if (clazztype.hasTag(CLASS)) {
5082             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5083             if (actuals.isEmpty()) //diamond
5084                 actuals = formals;
5085 
5086             if (actuals.length() == formals.length()) {
5087                 List<Type> a = actuals;
5088                 List<Type> f = formals;
5089                 while (a.nonEmpty()) {
5090                     a.head = a.head.withTypeVar(f.head);
5091                     a = a.tail;
5092                     f = f.tail;
5093                 }
5094                 // Compute the proper generic outer
5095                 Type clazzOuter = clazztype.getEnclosingType();
5096                 if (clazzOuter.hasTag(CLASS)) {
5097                     Type site;
5098                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5099                     if (clazz.hasTag(IDENT)) {
5100                         site = env.enclClass.sym.type;
5101                     } else if (clazz.hasTag(SELECT)) {
5102                         site = ((JCFieldAccess) clazz).selected.type;
5103                     } else throw new AssertionError(""+tree);
5104                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5105                         if (site.hasTag(CLASS) || site.hasTag(TYPEVAR))
5106                             site = types.asEnclosingSuper(site, clazzOuter.tsym);
5107                         if (site == null)
5108                             site = types.erasure(clazzOuter);
5109                         clazzOuter = site;
5110                     }
5111                 }
5112                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5113                                         clazztype.getMetadata());
5114             } else {
5115                 if (formals.length() != 0) {
5116                     log.error(tree.pos(),
5117                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5118                 } else {
5119                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5120                 }
5121                 owntype = types.createErrorType(tree.type);
5122             }
5123         } else if (clazztype.hasTag(ERROR)) {
5124             ErrorType parameterizedErroneous =
5125                     new ErrorType(clazztype.getOriginalType(),
5126                                   clazztype.tsym,
5127                                   clazztype.getMetadata());
5128 
5129             parameterizedErroneous.typarams_field = actuals;
5130             owntype = parameterizedErroneous;
5131         }
5132         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5133     }
5134 
5135     public void visitTypeUnion(JCTypeUnion tree) {
5136         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5137         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5138         for (JCExpression typeTree : tree.alternatives) {
5139             Type ctype = attribType(typeTree, env);
5140             ctype = chk.checkType(typeTree.pos(),
5141                           chk.checkClassType(typeTree.pos(), ctype),
5142                           syms.throwableType);
5143             if (!ctype.isErroneous()) {
5144                 //check that alternatives of a union type are pairwise
5145                 //unrelated w.r.t. subtyping
5146                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5147                     for (Type t : multicatchTypes) {
5148                         boolean sub = types.isSubtype(ctype, t);
5149                         boolean sup = types.isSubtype(t, ctype);
5150                         if (sub || sup) {
5151                             //assume 'a' <: 'b'
5152                             Type a = sub ? ctype : t;
5153                             Type b = sub ? t : ctype;
5154                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5155                         }
5156                     }
5157                 }
5158                 multicatchTypes.append(ctype);
5159                 if (all_multicatchTypes != null)
5160                     all_multicatchTypes.append(ctype);
5161             } else {
5162                 if (all_multicatchTypes == null) {
5163                     all_multicatchTypes = new ListBuffer<>();
5164                     all_multicatchTypes.appendList(multicatchTypes);
5165                 }
5166                 all_multicatchTypes.append(ctype);
5167             }
5168         }
5169         Type t = check(tree, types.lub(multicatchTypes.toList()),
5170                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5171         if (t.hasTag(CLASS)) {
5172             List<Type> alternatives =
5173                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5174             t = new UnionClassType((ClassType) t, alternatives);
5175         }
5176         tree.type = result = t;
5177     }
5178 
5179     public void visitTypeIntersection(JCTypeIntersection tree) {
5180         attribTypes(tree.bounds, env);
5181         tree.type = result = checkIntersection(tree, tree.bounds);
5182     }
5183 
5184     public void visitTypeParameter(JCTypeParameter tree) {
5185         TypeVar typeVar = (TypeVar) tree.type;
5186 
5187         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5188             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5189         }
5190 
5191         if (!typeVar.getUpperBound().isErroneous()) {
5192             //fixup type-parameter bound computed in 'attribTypeVariables'
5193             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5194         }
5195     }
5196 
5197     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5198         Set<Symbol> boundSet = new HashSet<>();
5199         if (bounds.nonEmpty()) {
5200             // accept class or interface or typevar as first bound.
5201             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5202             boundSet.add(types.erasure(bounds.head.type).tsym);
5203             if (bounds.head.type.isErroneous()) {
5204                 return bounds.head.type;
5205             }
5206             else if (bounds.head.type.hasTag(TYPEVAR)) {
5207                 // if first bound was a typevar, do not accept further bounds.
5208                 if (bounds.tail.nonEmpty()) {
5209                     log.error(bounds.tail.head.pos(),
5210                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5211                     return bounds.head.type;
5212                 }
5213             } else {
5214                 // if first bound was a class or interface, accept only interfaces
5215                 // as further bounds.
5216                 for (JCExpression bound : bounds.tail) {
5217                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5218                     if (bound.type.isErroneous()) {
5219                         bounds = List.of(bound);
5220                     }
5221                     else if (bound.type.hasTag(CLASS)) {
5222                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5223                     }
5224                 }
5225             }
5226         }
5227 
5228         if (bounds.length() == 0) {
5229             return syms.objectType;
5230         } else if (bounds.length() == 1) {
5231             return bounds.head.type;
5232         } else {
5233             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5234             // ... the variable's bound is a class type flagged COMPOUND
5235             // (see comment for TypeVar.bound).
5236             // In this case, generate a class tree that represents the
5237             // bound class, ...
5238             JCExpression extending;
5239             List<JCExpression> implementing;
5240             if (!bounds.head.type.isInterface()) {
5241                 extending = bounds.head;
5242                 implementing = bounds.tail;
5243             } else {
5244                 extending = null;
5245                 implementing = bounds;
5246             }
5247             JCClassDecl cd = make.at(tree).ClassDef(
5248                 make.Modifiers(PUBLIC | ABSTRACT),
5249                 names.empty, List.nil(),
5250                 extending, implementing, List.nil());
5251 
5252             ClassSymbol c = (ClassSymbol)owntype.tsym;
5253             Assert.check((c.flags() & COMPOUND) != 0);
5254             cd.sym = c;
5255             c.sourcefile = env.toplevel.sourcefile;
5256 
5257             // ... and attribute the bound class
5258             c.flags_field |= UNATTRIBUTED;
5259             Env<AttrContext> cenv = enter.classEnv(cd, env);
5260             typeEnvs.put(c, cenv);
5261             attribClass(c);
5262             return owntype;
5263         }
5264     }
5265 
5266     public void visitWildcard(JCWildcard tree) {
5267         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5268         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5269             ? syms.objectType
5270             : attribType(tree.inner, env);
5271         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
5272                                               tree.kind.kind,
5273                                               syms.boundClass),
5274                 KindSelector.TYP, resultInfo);
5275     }
5276 
5277     public void visitAnnotation(JCAnnotation tree) {
5278         Assert.error("should be handled in annotate");
5279     }
5280 
5281     @Override
5282     public void visitModifiers(JCModifiers tree) {
5283         //error recovery only:
5284         Assert.check(resultInfo.pkind == KindSelector.ERR);
5285 
5286         attribAnnotationTypes(tree.annotations, env);
5287     }
5288 
5289     public void visitAnnotatedType(JCAnnotatedType tree) {
5290         attribAnnotationTypes(tree.annotations, env);
5291         Type underlyingType = attribTree(tree.underlyingType, env, resultInfo);
5292         if (underlyingType.getTag() == PACKAGE || underlyingType.getTag() == VOID) {
5293             result = tree.type = underlyingType;
5294         } else {
5295             Type annotatedType = underlyingType.preannotatedType();
5296 
5297             annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5298             result = tree.type = annotatedType;
5299         }
5300     }
5301 
5302     public void visitErroneous(JCErroneous tree) {
5303         if (tree.errs != null) {
5304             WriteableScope newScope = env.info.scope;
5305 
5306             if (env.tree instanceof JCClassDecl) {
5307                 Symbol fakeOwner =
5308                     new MethodSymbol(BLOCK, names.empty, null,
5309                         env.info.scope.owner);
5310                 newScope = newScope.dupUnshared(fakeOwner);
5311             }
5312 
5313             Env<AttrContext> errEnv =
5314                     env.dup(env.tree,
5315                             env.info.dup(newScope));
5316             errEnv.info.returnResult = unknownExprInfo;
5317             for (JCTree err : tree.errs)
5318                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5319         }
5320         result = tree.type = syms.errType;
5321     }
5322 
5323     /** Default visitor method for all other trees.
5324      */
5325     public void visitTree(JCTree tree) {
5326         throw new AssertionError();
5327     }
5328 
5329     /**
5330      * Attribute an env for either a top level tree or class or module declaration.
5331      */
5332     public void attrib(Env<AttrContext> env) {
5333         switch (env.tree.getTag()) {
5334             case MODULEDEF:
5335                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5336                 break;
5337             case PACKAGEDEF:
5338                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5339                 break;
5340             default:
5341                 attribClass(env.tree.pos(), env.enclClass.sym);
5342         }
5343 
5344         annotate.flush();
5345 
5346         // Now that this tree is attributed, we can calculate the Lint configuration everywhere within it
5347         lintMapper.calculateLints(env.toplevel.sourcefile, env.tree);
5348     }
5349 
5350     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5351         try {
5352             annotate.flush();
5353             attribPackage(p);
5354         } catch (CompletionFailure ex) {
5355             chk.completionError(pos, ex);
5356         }
5357     }
5358 
5359     void attribPackage(PackageSymbol p) {
5360         attribWithLint(p,
5361                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5362     }
5363 
5364     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5365         try {
5366             annotate.flush();
5367             attribModule(m);
5368         } catch (CompletionFailure ex) {
5369             chk.completionError(pos, ex);
5370         }
5371     }
5372 
5373     void attribModule(ModuleSymbol m) {
5374         attribWithLint(m, env -> attribStat(env.tree, env));
5375     }
5376 
5377     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5378         Env<AttrContext> env = typeEnvs.get(sym);
5379 
5380         Env<AttrContext> lintEnv = env;
5381         while (lintEnv.info.lint == null)
5382             lintEnv = lintEnv.next;
5383 
5384         Lint lint = lintEnv.info.lint.augment(sym);
5385 
5386         Lint prevLint = chk.setLint(lint);
5387         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5388 
5389         try {
5390             attrib.accept(env);
5391         } finally {
5392             log.useSource(prev);
5393             chk.setLint(prevLint);
5394         }
5395     }
5396 
5397     /** Main method: attribute class definition associated with given class symbol.
5398      *  reporting completion failures at the given position.
5399      *  @param pos The source position at which completion errors are to be
5400      *             reported.
5401      *  @param c   The class symbol whose definition will be attributed.
5402      */
5403     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5404         try {
5405             annotate.flush();
5406             attribClass(c);
5407         } catch (CompletionFailure ex) {
5408             chk.completionError(pos, ex);
5409         }
5410     }
5411 
5412     /** Attribute class definition associated with given class symbol.
5413      *  @param c   The class symbol whose definition will be attributed.
5414      */
5415     void attribClass(ClassSymbol c) throws CompletionFailure {
5416         if (c.type.hasTag(ERROR)) return;
5417 
5418         // Check for cycles in the inheritance graph, which can arise from
5419         // ill-formed class files.
5420         chk.checkNonCyclic(null, c.type);
5421 
5422         Type st = types.supertype(c.type);
5423         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5424             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0 &&
5425             breakTree == null) {
5426             // First, attribute superclass.
5427             if (st.hasTag(CLASS))
5428                 attribClass((ClassSymbol)st.tsym);
5429 
5430             // Next attribute owner, if it is a class.
5431             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5432                 attribClass((ClassSymbol)c.owner);
5433 
5434             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5435         }
5436 
5437         // The previous operations might have attributed the current class
5438         // if there was a cycle. So we test first whether the class is still
5439         // UNATTRIBUTED.
5440         if ((c.flags_field & UNATTRIBUTED) != 0) {
5441             c.flags_field &= ~UNATTRIBUTED;
5442 
5443             // Get environment current at the point of class definition.
5444             Env<AttrContext> env = typeEnvs.get(c);
5445 
5446             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5447             // because the annotations were not available at the time the env was created. Therefore,
5448             // we look up the environment chain for the first enclosing environment for which the
5449             // lint value is set. Typically, this is the parent env, but might be further if there
5450             // are any envs created as a result of TypeParameter nodes.
5451             Env<AttrContext> lintEnv = env;
5452             while (lintEnv.info.lint == null)
5453                 lintEnv = lintEnv.next;
5454 
5455             // Having found the enclosing lint value, we can initialize the lint value for this class
5456             env.info.lint = lintEnv.info.lint.augment(c);
5457 
5458             Lint prevLint = chk.setLint(env.info.lint);
5459             JavaFileObject prev = log.useSource(c.sourcefile);
5460             ResultInfo prevReturnRes = env.info.returnResult;
5461 
5462             try {
5463                 if (c.isSealed() &&
5464                         !c.isEnum() &&
5465                         !c.isPermittedExplicit &&
5466                         c.getPermittedSubclasses().isEmpty()) {
5467                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5468                 }
5469 
5470                 if (c.isSealed()) {
5471                     Set<Symbol> permittedTypes = new HashSet<>();
5472                     boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5473                     for (Type subType : c.getPermittedSubclasses()) {
5474                         if (subType.isErroneous()) {
5475                             // the type already caused errors, don't produce more potentially misleading errors
5476                             continue;
5477                         }
5478                         boolean isTypeVar = false;
5479                         if (subType.getTag() == TYPEVAR) {
5480                             isTypeVar = true; //error recovery
5481                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5482                                     Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subType)));
5483                         }
5484                         if (subType.tsym.isAnonymous() && !c.isEnum()) {
5485                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5486                         }
5487                         if (permittedTypes.contains(subType.tsym)) {
5488                             DiagnosticPosition pos =
5489                                     env.enclClass.permitting.stream()
5490                                             .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subType.tsym, permittedExpr, true) != null)
5491                                             .limit(2).collect(List.collector()).get(1);
5492                             log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subType)));
5493                         } else {
5494                             permittedTypes.add(subType.tsym);
5495                         }
5496                         if (sealedInUnnamed) {
5497                             if (subType.tsym.packge() != c.packge()) {
5498                                 log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5499                                         Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5500                                 );
5501                             }
5502                         } else if (subType.tsym.packge().modle != c.packge().modle) {
5503                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5504                                     Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5505                             );
5506                         }
5507                         if (subType.tsym == c.type.tsym || types.isSuperType(subType, c.type)) {
5508                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, ((JCClassDecl)env.tree).permitting),
5509                                     Errors.InvalidPermitsClause(
5510                                             subType.tsym == c.type.tsym ?
5511                                                     Fragments.MustNotBeSameClass :
5512                                                     Fragments.MustNotBeSupertype(subType)
5513                                     )
5514                             );
5515                         } else if (!isTypeVar) {
5516                             boolean thisIsASuper = types.directSupertypes(subType)
5517                                                         .stream()
5518                                                         .anyMatch(d -> d.tsym == c);
5519                             if (!thisIsASuper) {
5520                                 if(c.isInterface()) {
5521                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5522                                             Errors.InvalidPermitsClause(Fragments.DoesntImplementSealed(kindName(subType.tsym), subType)));
5523                                 } else {
5524                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5525                                             Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subType)));
5526                                 }
5527                             }
5528                         }
5529                     }
5530                 }
5531 
5532                 List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5533                                                       .stream()
5534                                                       .filter(s -> s.tsym.isSealed())
5535                                                       .map(s -> (ClassSymbol) s.tsym)
5536                                                       .collect(List.collector());
5537 
5538                 if (sealedSupers.isEmpty()) {
5539                     if ((c.flags_field & Flags.NON_SEALED) != 0) {
5540                         boolean hasErrorSuper = false;
5541 
5542                         hasErrorSuper |= types.directSupertypes(c.type)
5543                                               .stream()
5544                                               .anyMatch(s -> s.tsym.kind == Kind.ERR);
5545 
5546                         ClassType ct = (ClassType) c.type;
5547 
5548                         hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5549 
5550                         if (!hasErrorSuper) {
5551                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5552                         }
5553                     }
5554                 } else {
5555                     if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5556                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5557                     }
5558 
5559                     if (!c.type.isCompound()) {
5560                         for (ClassSymbol supertypeSym : sealedSupers) {
5561                             if (!supertypeSym.isPermittedSubclass(c.type.tsym)) {
5562                                 log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5563                             }
5564                         }
5565                         if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5566                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5567                                     c.isInterface() ?
5568                                             Errors.NonSealedOrSealedExpected :
5569                                             Errors.NonSealedSealedOrFinalExpected);
5570                         }
5571                     }
5572                 }
5573 
5574                 env.info.returnResult = null;
5575                 // java.lang.Enum may not be subclassed by a non-enum
5576                 if (st.tsym == syms.enumSym &&
5577                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5578                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5579 
5580                 // Enums may not be extended by source-level classes
5581                 if (st.tsym != null &&
5582                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5583                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5584                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5585                 }
5586 
5587                 if (rs.isSerializable(c.type)) {
5588                     env.info.isSerializable = true;
5589                 }
5590 
5591                 attribClassBody(env, c);
5592 
5593                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5594                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5595                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5596                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5597 
5598                 if (c.isImplicit()) {
5599                     chk.checkHasMain(env.tree.pos(), c);
5600                 }
5601             } finally {
5602                 env.info.returnResult = prevReturnRes;
5603                 log.useSource(prev);
5604                 chk.setLint(prevLint);
5605             }
5606 
5607         }
5608     }
5609 
5610     public void visitImport(JCImport tree) {
5611         // nothing to do
5612     }
5613 
5614     public void visitModuleDef(JCModuleDecl tree) {
5615         tree.sym.completeUsesProvides();
5616         ModuleSymbol msym = tree.sym;
5617         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5618         Lint prevLint = chk.setLint(lint);
5619         try {
5620             chk.checkModuleName(tree);
5621             chk.checkDeprecatedAnnotation(tree, msym);
5622         } finally {
5623             chk.setLint(prevLint);
5624         }
5625     }
5626 
5627     /** Finish the attribution of a class. */
5628     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5629         JCClassDecl tree = (JCClassDecl)env.tree;
5630         Assert.check(c == tree.sym);
5631 
5632         // Validate type parameters, supertype and interfaces.
5633         attribStats(tree.typarams, env);
5634         if (!c.isAnonymous()) {
5635             //already checked if anonymous
5636             chk.validate(tree.typarams, env);
5637             chk.validate(tree.extending, env);
5638             chk.validate(tree.implementing, env);
5639         }
5640 
5641         chk.checkRequiresIdentity(tree, env.info.lint);
5642 
5643         c.markAbstractIfNeeded(types);
5644 
5645         // If this is a non-abstract class, check that it has no abstract
5646         // methods or unimplemented methods of an implemented interface.
5647         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
5648             chk.checkAllDefined(tree.pos(), c);
5649         }
5650 
5651         if ((c.flags() & ANNOTATION) != 0) {
5652             if (tree.implementing.nonEmpty())
5653                 log.error(tree.implementing.head.pos(),
5654                           Errors.CantExtendIntfAnnotation);
5655             if (tree.typarams.nonEmpty()) {
5656                 log.error(tree.typarams.head.pos(),
5657                           Errors.IntfAnnotationCantHaveTypeParams(c));
5658             }
5659 
5660             // If this annotation type has a @Repeatable, validate
5661             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
5662             // If this annotation type has a @Repeatable, validate
5663             if (repeatable != null) {
5664                 // get diagnostic position for error reporting
5665                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
5666                 Assert.checkNonNull(cbPos);
5667 
5668                 chk.validateRepeatable(c, repeatable, cbPos);
5669             }
5670         } else {
5671             try {
5672                 // Check that all extended classes and interfaces
5673                 // are compatible (i.e. no two define methods with same arguments
5674                 // yet different return types).  (JLS 8.4.8.3)
5675                 chk.checkCompatibleSupertypes(tree.pos(), c.type);
5676                 chk.checkDefaultMethodClashes(tree.pos(), c.type);
5677                 chk.checkPotentiallyAmbiguousOverloads(tree, c.type);
5678             } catch (CompletionFailure cf) {
5679                 chk.completionError(tree.pos(), cf);
5680             }
5681         }
5682 
5683         // Check that class does not import the same parameterized interface
5684         // with two different argument lists.
5685         chk.checkClassBounds(tree.pos(), c.type);
5686 
5687         tree.type = c.type;
5688 
5689         for (List<JCTypeParameter> l = tree.typarams;
5690              l.nonEmpty(); l = l.tail) {
5691              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
5692         }
5693 
5694         // Check that a generic class doesn't extend Throwable
5695         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
5696             log.error(tree.extending.pos(), Errors.GenericThrowable);
5697 
5698         // Check that all methods which implement some
5699         // method conform to the method they implement.
5700         chk.checkImplementations(tree);
5701 
5702         //check that a resource implementing AutoCloseable cannot throw InterruptedException
5703         checkAutoCloseable(env, tree, false);
5704 
5705         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
5706             // Attribute declaration
5707             attribStat(l.head, env);
5708             // Check that declarations in inner classes are not static (JLS 8.1.2)
5709             // Make an exception for static constants.
5710             if (!allowRecords &&
5711                     c.owner.kind != PCK &&
5712                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
5713                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
5714                 VarSymbol sym = null;
5715                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
5716                 if (sym == null ||
5717                         sym.kind != VAR ||
5718                         sym.getConstValue() == null)
5719                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
5720             }
5721         }
5722 
5723         // Check for proper placement of super()/this() calls.
5724         chk.checkSuperInitCalls(tree);
5725 
5726         // Check for cycles among non-initial constructors.
5727         chk.checkCyclicConstructors(tree);
5728 
5729         // Check for cycles among annotation elements.
5730         chk.checkNonCyclicElements(tree);
5731 
5732         // Check for proper use of serialVersionUID and other
5733         // serialization-related fields and methods
5734         if (env.info.lint.isEnabled(LintCategory.SERIAL)
5735                 && rs.isSerializable(c.type)
5736                 && !c.isAnonymous()) {
5737             chk.checkSerialStructure(tree, c);
5738         }
5739         // Correctly organize the positions of the type annotations
5740         typeAnnotations.organizeTypeAnnotationsBodies(tree);
5741 
5742         // Check type annotations applicability rules
5743         validateTypeAnnotations(tree, false);
5744     }
5745         // where
5746         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
5747         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
5748             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
5749                 if (types.isSameType(al.head.annotationType.type, t))
5750                     return al.head.pos();
5751             }
5752 
5753             return null;
5754         }
5755 
5756     private Type capture(Type type) {
5757         return types.capture(type);
5758     }
5759 
5760     private void setupImplicitlyTypedVariable(JCVariableDecl tree, Type type) {
5761         Assert.check(tree.isImplicitlyTyped());
5762 
5763         type.complete();
5764 
5765         if (tree.vartype == null) {
5766             return ;
5767         }
5768 
5769         Assert.check(tree.vartype.hasTag(VARTYPE));
5770 
5771         JCVarType vartype = (JCVarType) tree.vartype;
5772 
5773         vartype.type = type;
5774     }
5775 
5776     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
5777         tree.accept(new TypeAnnotationsValidator(sigOnly));
5778     }
5779     //where
5780     private final class TypeAnnotationsValidator extends TreeScanner {
5781 
5782         private final boolean sigOnly;
5783         public TypeAnnotationsValidator(boolean sigOnly) {
5784             this.sigOnly = sigOnly;
5785         }
5786 
5787         public void visitAnnotation(JCAnnotation tree) {
5788             chk.validateTypeAnnotation(tree, null, false);
5789             super.visitAnnotation(tree);
5790         }
5791         public void visitAnnotatedType(JCAnnotatedType tree) {
5792             if (!tree.underlyingType.type.isErroneous()) {
5793                 super.visitAnnotatedType(tree);
5794             }
5795         }
5796         public void visitTypeParameter(JCTypeParameter tree) {
5797             chk.validateTypeAnnotations(tree.annotations, tree.type.tsym, true);
5798             scan(tree.bounds);
5799             // Don't call super.
5800             // This is needed because above we call validateTypeAnnotation with
5801             // false, which would forbid annotations on type parameters.
5802             // super.visitTypeParameter(tree);
5803         }
5804         public void visitMethodDef(JCMethodDecl tree) {
5805             if (tree.recvparam != null &&
5806                     !tree.recvparam.vartype.type.isErroneous()) {
5807                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
5808             }
5809             if (tree.restype != null && tree.restype.type != null) {
5810                 validateAnnotatedType(tree.restype, tree.restype.type);
5811             }
5812             if (sigOnly) {
5813                 scan(tree.mods);
5814                 scan(tree.restype);
5815                 scan(tree.typarams);
5816                 scan(tree.recvparam);
5817                 scan(tree.params);
5818                 scan(tree.thrown);
5819             } else {
5820                 scan(tree.defaultValue);
5821                 scan(tree.body);
5822             }
5823         }
5824         public void visitVarDef(final JCVariableDecl tree) {
5825             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
5826             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
5827                 validateAnnotatedType(tree.vartype, tree.sym.type);
5828             scan(tree.mods);
5829             scan(tree.vartype);
5830             if (!sigOnly) {
5831                 scan(tree.init);
5832             }
5833         }
5834         public void visitTypeCast(JCTypeCast tree) {
5835             if (tree.clazz != null && tree.clazz.type != null)
5836                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5837             super.visitTypeCast(tree);
5838         }
5839         public void visitTypeTest(JCInstanceOf tree) {
5840             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
5841                 validateAnnotatedType(tree.pattern, tree.pattern.type);
5842             super.visitTypeTest(tree);
5843         }
5844         public void visitNewClass(JCNewClass tree) {
5845             if (tree.clazz != null && tree.clazz.type != null) {
5846                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
5847                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
5848                             tree.clazz.type.tsym);
5849                 }
5850                 if (tree.def != null) {
5851                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
5852                 }
5853 
5854                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5855             }
5856             super.visitNewClass(tree);
5857         }
5858         public void visitNewArray(JCNewArray tree) {
5859             if (tree.elemtype != null && tree.elemtype.type != null) {
5860                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
5861                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
5862                             tree.elemtype.type.tsym);
5863                 }
5864                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
5865             }
5866             super.visitNewArray(tree);
5867         }
5868         public void visitClassDef(JCClassDecl tree) {
5869             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
5870             if (sigOnly) {
5871                 scan(tree.mods);
5872                 scan(tree.typarams);
5873                 scan(tree.extending);
5874                 scan(tree.implementing);
5875             }
5876             for (JCTree member : tree.defs) {
5877                 if (member.hasTag(Tag.CLASSDEF)) {
5878                     continue;
5879                 }
5880                 scan(member);
5881             }
5882         }
5883         public void visitBlock(JCBlock tree) {
5884             if (!sigOnly) {
5885                 scan(tree.stats);
5886             }
5887         }
5888 
5889         /* I would want to model this after
5890          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
5891          * and override visitSelect and visitTypeApply.
5892          * However, we only set the annotated type in the top-level type
5893          * of the symbol.
5894          * Therefore, we need to override each individual location where a type
5895          * can occur.
5896          */
5897         private void validateAnnotatedType(final JCTree errtree, final Type type) {
5898             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
5899 
5900             if (type.isPrimitiveOrVoid()) {
5901                 return;
5902             }
5903 
5904             JCTree enclTr = errtree;
5905             Type enclTy = type;
5906 
5907             boolean repeat = true;
5908             while (repeat) {
5909                 if (enclTr.hasTag(TYPEAPPLY)) {
5910                     List<Type> tyargs = enclTy.getTypeArguments();
5911                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
5912                     if (trargs.length() > 0) {
5913                         // Nothing to do for diamonds
5914                         if (tyargs.length() == trargs.length()) {
5915                             for (int i = 0; i < tyargs.length(); ++i) {
5916                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
5917                             }
5918                         }
5919                         // If the lengths don't match, it's either a diamond
5920                         // or some nested type that redundantly provides
5921                         // type arguments in the tree.
5922                     }
5923 
5924                     // Look at the clazz part of a generic type
5925                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
5926                 }
5927 
5928                 if (enclTr.hasTag(SELECT)) {
5929                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
5930                     if (enclTy != null &&
5931                             !enclTy.hasTag(NONE)) {
5932                         enclTy = enclTy.getEnclosingType();
5933                     }
5934                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
5935                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
5936                     if (enclTy == null || enclTy.hasTag(NONE)) {
5937                         ListBuffer<Attribute.TypeCompound> onlyTypeAnnotationsBuf = new ListBuffer<>();
5938                         for (JCAnnotation an : at.getAnnotations()) {
5939                             if (chk.isTypeAnnotation(an, false)) {
5940                                 onlyTypeAnnotationsBuf.add((Attribute.TypeCompound) an.attribute);
5941                             }
5942                         }
5943                         List<Attribute.TypeCompound> onlyTypeAnnotations = onlyTypeAnnotationsBuf.toList();
5944                         if (!onlyTypeAnnotations.isEmpty()) {
5945                             Fragment annotationFragment = onlyTypeAnnotations.size() == 1 ?
5946                                     Fragments.TypeAnnotation1(onlyTypeAnnotations.head) :
5947                                     Fragments.TypeAnnotation(onlyTypeAnnotations);
5948                             JCDiagnostic.AnnotatedType annotatedType = new JCDiagnostic.AnnotatedType(
5949                                     type.stripMetadata().annotatedType(onlyTypeAnnotations));
5950                             log.error(at.underlyingType.pos(), Errors.TypeAnnotationInadmissible(annotationFragment,
5951                                     type.tsym.owner, annotatedType));
5952                         }
5953                         repeat = false;
5954                     }
5955                     enclTr = at.underlyingType;
5956                     // enclTy doesn't need to be changed
5957                 } else if (enclTr.hasTag(IDENT)) {
5958                     repeat = false;
5959                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
5960                     JCWildcard wc = (JCWildcard) enclTr;
5961                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
5962                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
5963                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
5964                     } else {
5965                         // Nothing to do for UNBOUND
5966                     }
5967                     repeat = false;
5968                 } else if (enclTr.hasTag(TYPEARRAY)) {
5969                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
5970                     validateAnnotatedType(art.getType(), art.elemtype.type);
5971                     repeat = false;
5972                 } else if (enclTr.hasTag(TYPEUNION)) {
5973                     JCTypeUnion ut = (JCTypeUnion) enclTr;
5974                     for (JCTree t : ut.getTypeAlternatives()) {
5975                         validateAnnotatedType(t, t.type);
5976                     }
5977                     repeat = false;
5978                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
5979                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
5980                     for (JCTree t : it.getBounds()) {
5981                         validateAnnotatedType(t, t.type);
5982                     }
5983                     repeat = false;
5984                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
5985                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
5986                     repeat = false;
5987                 } else {
5988                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
5989                             " within: "+ errtree + " with kind: " + errtree.getKind());
5990                 }
5991             }
5992         }
5993 
5994         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
5995                 Symbol sym) {
5996             // Ensure that no declaration annotations are present.
5997             // Note that a tree type might be an AnnotatedType with
5998             // empty annotations, if only declaration annotations were given.
5999             // This method will raise an error for such a type.
6000             for (JCAnnotation ai : annotations) {
6001                 if (!ai.type.isErroneous() &&
6002                         typeAnnotations.annotationTargetType(ai, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
6003                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
6004                 }
6005             }
6006         }
6007     }
6008 
6009     // <editor-fold desc="post-attribution visitor">
6010 
6011     /**
6012      * Handle missing types/symbols in an AST. This routine is useful when
6013      * the compiler has encountered some errors (which might have ended up
6014      * terminating attribution abruptly); if the compiler is used in fail-over
6015      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
6016      * prevents NPE to be propagated during subsequent compilation steps.
6017      */
6018     public void postAttr(JCTree tree) {
6019         new PostAttrAnalyzer().scan(tree);
6020     }
6021 
6022     class PostAttrAnalyzer extends TreeScanner {
6023 
6024         private void initTypeIfNeeded(JCTree that) {
6025             if (that.type == null) {
6026                 if (that.hasTag(METHODDEF)) {
6027                     that.type = dummyMethodType((JCMethodDecl)that);
6028                 } else {
6029                     that.type = syms.unknownType;
6030                 }
6031             }
6032         }
6033 
6034         /* Construct a dummy method type. If we have a method declaration,
6035          * and the declared return type is void, then use that return type
6036          * instead of UNKNOWN to avoid spurious error messages in lambda
6037          * bodies (see:JDK-8041704).
6038          */
6039         private Type dummyMethodType(JCMethodDecl md) {
6040             Type restype = syms.unknownType;
6041             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
6042                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
6043                 if (prim.typetag == VOID)
6044                     restype = syms.voidType;
6045             }
6046             return new MethodType(List.nil(), restype,
6047                                   List.nil(), syms.methodClass);
6048         }
6049         private Type dummyMethodType() {
6050             return dummyMethodType(null);
6051         }
6052 
6053         @Override
6054         public void scan(JCTree tree) {
6055             if (tree == null) return;
6056             if (tree instanceof JCExpression) {
6057                 initTypeIfNeeded(tree);
6058             }
6059             super.scan(tree);
6060         }
6061 
6062         @Override
6063         public void visitIdent(JCIdent that) {
6064             if (that.sym == null) {
6065                 that.sym = syms.unknownSymbol;
6066             }
6067         }
6068 
6069         @Override
6070         public void visitSelect(JCFieldAccess that) {
6071             if (that.sym == null) {
6072                 that.sym = syms.unknownSymbol;
6073             }
6074             super.visitSelect(that);
6075         }
6076 
6077         @Override
6078         public void visitClassDef(JCClassDecl that) {
6079             initTypeIfNeeded(that);
6080             if (that.sym == null) {
6081                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
6082             }
6083             super.visitClassDef(that);
6084         }
6085 
6086         @Override
6087         public void visitMethodDef(JCMethodDecl that) {
6088             initTypeIfNeeded(that);
6089             if (that.sym == null) {
6090                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
6091             }
6092             super.visitMethodDef(that);
6093         }
6094 
6095         @Override
6096         public void visitVarDef(JCVariableDecl that) {
6097             initTypeIfNeeded(that);
6098             if (that.sym == null) {
6099                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
6100                 that.sym.adr = 0;
6101             }
6102             super.visitVarDef(that);
6103         }
6104 
6105         @Override
6106         public void visitBindingPattern(JCBindingPattern that) {
6107             initTypeIfNeeded(that);
6108             initTypeIfNeeded(that.var);
6109             if (that.var.sym == null) {
6110                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6111                 that.var.sym.adr = 0;
6112             }
6113             super.visitBindingPattern(that);
6114         }
6115 
6116         @Override
6117         public void visitRecordPattern(JCRecordPattern that) {
6118             initTypeIfNeeded(that);
6119             if (that.record == null) {
6120                 that.record = new ClassSymbol(0, TreeInfo.name(that.deconstructor),
6121                                               that.type, syms.noSymbol);
6122             }
6123             if (that.fullComponentTypes == null) {
6124                 that.fullComponentTypes = List.nil();
6125             }
6126             super.visitRecordPattern(that);
6127         }
6128 
6129         @Override
6130         public void visitNewClass(JCNewClass that) {
6131             if (that.constructor == null) {
6132                 that.constructor = new MethodSymbol(0, names.init,
6133                         dummyMethodType(), syms.noSymbol);
6134             }
6135             if (that.constructorType == null) {
6136                 that.constructorType = syms.unknownType;
6137             }
6138             super.visitNewClass(that);
6139         }
6140 
6141         @Override
6142         public void visitAssignop(JCAssignOp that) {
6143             if (that.operator == null) {
6144                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6145                         -1, syms.noSymbol);
6146             }
6147             super.visitAssignop(that);
6148         }
6149 
6150         @Override
6151         public void visitBinary(JCBinary that) {
6152             if (that.operator == null) {
6153                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6154                         -1, syms.noSymbol);
6155             }
6156             super.visitBinary(that);
6157         }
6158 
6159         @Override
6160         public void visitUnary(JCUnary that) {
6161             if (that.operator == null) {
6162                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6163                         -1, syms.noSymbol);
6164             }
6165             super.visitUnary(that);
6166         }
6167 
6168         @Override
6169         public void visitReference(JCMemberReference that) {
6170             super.visitReference(that);
6171             if (that.sym == null) {
6172                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6173                         syms.noSymbol);
6174             }
6175         }
6176 
6177         @Override
6178         public void visitVarType(JCVarType that) {
6179             initTypeIfNeeded(that);
6180         }
6181     }
6182     // </editor-fold>
6183 
6184     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6185         new TreeScanner() {
6186             Symbol packge = pkg;
6187             @Override
6188             public void visitIdent(JCIdent that) {
6189                 that.sym = packge;
6190             }
6191 
6192             @Override
6193             public void visitSelect(JCFieldAccess that) {
6194                 that.sym = packge;
6195                 packge = packge.owner;
6196                 super.visitSelect(that);
6197             }
6198         }.scan(pid);
6199     }
6200 
6201 }