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.stream.Stream;
  32 
  33 import javax.lang.model.element.ElementKind;
  34 import javax.tools.JavaFileObject;
  35 
  36 import com.sun.source.tree.CaseTree;
  37 import com.sun.source.tree.IdentifierTree;
  38 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
  39 import com.sun.source.tree.MemberSelectTree;
  40 import com.sun.source.tree.TreeVisitor;
  41 import com.sun.source.util.SimpleTreeVisitor;
  42 import com.sun.tools.javac.code.*;
  43 import com.sun.tools.javac.code.Lint.LintCategory;
  44 import com.sun.tools.javac.code.LintMapper;
  45 import com.sun.tools.javac.code.Scope.WriteableScope;
  46 import com.sun.tools.javac.code.Source.Feature;
  47 import com.sun.tools.javac.code.Symbol.*;
  48 import com.sun.tools.javac.code.Type.*;
  49 import com.sun.tools.javac.code.Types.FunctionDescriptorLookupError;
  50 import com.sun.tools.javac.comp.ArgumentAttr.LocalCacheContext;
  51 import com.sun.tools.javac.comp.Check.CheckContext;
  52 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
  53 import com.sun.tools.javac.comp.MatchBindingsComputer.MatchBindings;
  54 import com.sun.tools.javac.jvm.*;
  55 
  56 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
  57 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
  58 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
  59 
  60 import com.sun.tools.javac.resources.CompilerProperties.Errors;
  61 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  62 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings;
  63 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
  64 import com.sun.tools.javac.tree.*;
  65 import com.sun.tools.javac.tree.JCTree.*;
  66 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
  67 import com.sun.tools.javac.util.*;
  68 import com.sun.tools.javac.util.DefinedBy.Api;
  69 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  70 import com.sun.tools.javac.util.JCDiagnostic.Error;
  71 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
  72 import com.sun.tools.javac.util.JCDiagnostic.Warning;
  73 import com.sun.tools.javac.util.List;
  74 
  75 import static com.sun.tools.javac.code.Flags.*;
  76 import static com.sun.tools.javac.code.Flags.ANNOTATION;
  77 import static com.sun.tools.javac.code.Flags.BLOCK;
  78 import static com.sun.tools.javac.code.Kinds.*;
  79 import static com.sun.tools.javac.code.Kinds.Kind.*;
  80 import static com.sun.tools.javac.code.TypeTag.*;
  81 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
  82 import static com.sun.tools.javac.tree.JCTree.Tag.*;
  83 
  84 /** This is the main context-dependent analysis phase in GJC. It
  85  *  encompasses name resolution, type checking and constant folding as
  86  *  subtasks. Some subtasks involve auxiliary classes.
  87  *  @see Check
  88  *  @see Resolve
  89  *  @see ConstFold
  90  *  @see Infer
  91  *
  92  *  <p><b>This is NOT part of any supported API.
  93  *  If you write code that depends on this, you do so at your own risk.
  94  *  This code and its internal interfaces are subject to change or
  95  *  deletion without notice.</b>
  96  */
  97 public class Attr extends JCTree.Visitor {
  98     protected static final Context.Key<Attr> attrKey = new Context.Key<>();
  99 
 100     final Names names;
 101     final Log log;
 102     final LintMapper lintMapper;
 103     final Symtab syms;
 104     final Resolve rs;
 105     final Operators operators;
 106     final Infer infer;
 107     final Analyzer analyzer;
 108     final DeferredAttr deferredAttr;
 109     final Check chk;
 110     final Flow flow;
 111     final MemberEnter memberEnter;
 112     final TypeEnter typeEnter;
 113     final TreeMaker make;
 114     final ConstFold cfolder;
 115     final Enter enter;
 116     final Target target;
 117     final Types types;
 118     final Preview preview;
 119     final JCDiagnostic.Factory diags;
 120     final TypeAnnotations typeAnnotations;
 121     final TypeEnvs typeEnvs;
 122     final Dependencies dependencies;
 123     final Annotate annotate;
 124     final ArgumentAttr argumentAttr;
 125     final MatchBindingsComputer matchBindingsComputer;
 126     final AttrRecover attrRecover;
 127     final boolean captureMRefReturnType;
 128 
 129     public static Attr instance(Context context) {
 130         Attr instance = context.get(attrKey);
 131         if (instance == null)
 132             instance = new Attr(context);
 133         return instance;
 134     }
 135 
 136     @SuppressWarnings("this-escape")
 137     protected Attr(Context context) {
 138         context.put(attrKey, this);
 139 
 140         names = Names.instance(context);
 141         log = Log.instance(context);
 142         lintMapper = LintMapper.instance(context);
 143         syms = Symtab.instance(context);
 144         rs = Resolve.instance(context);
 145         operators = Operators.instance(context);
 146         chk = Check.instance(context);
 147         flow = Flow.instance(context);
 148         memberEnter = MemberEnter.instance(context);
 149         typeEnter = TypeEnter.instance(context);
 150         make = TreeMaker.instance(context);
 151         enter = Enter.instance(context);
 152         infer = Infer.instance(context);
 153         analyzer = Analyzer.instance(context);
 154         deferredAttr = DeferredAttr.instance(context);
 155         cfolder = ConstFold.instance(context);
 156         target = Target.instance(context);
 157         types = Types.instance(context);
 158         preview = Preview.instance(context);
 159         diags = JCDiagnostic.Factory.instance(context);
 160         annotate = Annotate.instance(context);
 161         typeAnnotations = TypeAnnotations.instance(context);
 162         typeEnvs = TypeEnvs.instance(context);
 163         dependencies = Dependencies.instance(context);
 164         argumentAttr = ArgumentAttr.instance(context);
 165         matchBindingsComputer = MatchBindingsComputer.instance(context);
 166         attrRecover = AttrRecover.instance(context);
 167 
 168         Options options = Options.instance(context);
 169 
 170         Source source = Source.instance(context);
 171         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 172         allowRecords = Feature.RECORDS.allowedInSource(source);
 173         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 174                              Feature.PATTERN_SWITCH.allowedInSource(source);
 175         allowUnconditionalPatternsInstanceOf =
 176                              Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 177         sourceName = source.name;
 178         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 179         captureMRefReturnType = Source.Feature.CAPTURE_MREF_RETURN_TYPE.allowedInSource(source);
 180 
 181         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 182         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 183         varAssignmentOpInfo = new ResultInfo(KindSelector.of(KindSelector.VAL, 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         allowValueClasses = preview.isEnabled() && Feature.VALUE_CLASSES.allowedInSource(source);
 191     }
 192 
 193     /** Switch: reifiable types in instanceof enabled?
 194      */
 195     boolean allowReifiableTypesInInstanceof;
 196 
 197     /** Are records allowed
 198      */
 199     private final boolean allowRecords;
 200 
 201     /** Are patterns in switch allowed
 202      */
 203     private final boolean allowPatternSwitch;
 204 
 205     /** Are unconditional patterns in instanceof allowed
 206      */
 207     private final boolean allowUnconditionalPatternsInstanceOf;
 208 
 209     /** Are value classes allowed
 210      */
 211     private final boolean allowValueClasses;
 212 
 213     /**
 214      * Switch: warn about use of variable before declaration?
 215      * RFE: 6425594
 216      */
 217     boolean useBeforeDeclarationWarning;
 218 
 219     /**
 220      * Switch: name of source level; used for error reporting.
 221      */
 222     String sourceName;
 223 
 224     /** Check kind and type of given tree against protokind and prototype.
 225      *  If check succeeds, store type in tree and return it.
 226      *  If check fails, store errType in tree and return it.
 227      *  No checks are performed if the prototype is a method type.
 228      *  It is not necessary in this case since we know that kind and type
 229      *  are correct.
 230      *
 231      *  @param tree     The tree whose kind and type is checked
 232      *  @param found    The computed type of the tree
 233      *  @param ownkind  The computed kind of the tree
 234      *  @param resultInfo  The expected result of the tree
 235      */
 236     Type check(final JCTree tree,
 237                final Type found,
 238                final KindSelector ownkind,
 239                final ResultInfo resultInfo) {
 240         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 241         Type owntype;
 242         boolean shouldCheck = !found.hasTag(ERROR) &&
 243                 !resultInfo.pt.hasTag(METHOD) &&
 244                 !resultInfo.pt.hasTag(FORALL);
 245         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 246             log.error(tree.pos(),
 247                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 248                                             ownkind.kindNames()));
 249             owntype = types.createErrorType(found);
 250         } else if (inferenceContext.free(found)) {
 251             //delay the check if there are inference variables in the found type
 252             //this means we are dealing with a partially inferred poly expression
 253             owntype = shouldCheck ? resultInfo.pt : found;
 254             if (resultInfo.checkMode.installPostInferenceHook()) {
 255                 inferenceContext.addFreeTypeListener(List.of(found),
 256                         instantiatedContext -> {
 257                             ResultInfo pendingResult =
 258                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 259                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 260                         });
 261             }
 262         } else {
 263             owntype = shouldCheck ?
 264             resultInfo.check(tree, found) :
 265             found;
 266         }
 267         if (resultInfo.checkMode.updateTreeType()) {
 268             tree.type = owntype;
 269         }
 270         return owntype;
 271     }
 272 
 273     /** Is given blank final variable assignable, i.e. in a scope where it
 274      *  may be assigned to even though it is final?
 275      *  @param v      The blank final variable.
 276      *  @param env    The current environment.
 277      */
 278     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 279         Symbol owner = env.info.scope.owner;
 280            // owner refers to the innermost variable, method or
 281            // initializer block declaration at this point.
 282         boolean isAssignable =
 283             v.owner == owner
 284             ||
 285             ((owner.name == names.init ||    // i.e. we are in a constructor
 286               owner.kind == VAR ||           // i.e. we are in a variable initializer
 287               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 288              &&
 289              v.owner == owner.owner
 290              &&
 291              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 292         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 293         return isAssignable & !insideCompactConstructor;
 294     }
 295 
 296     /** Check that variable can be assigned to.
 297      *  @param pos    The current source code position.
 298      *  @param v      The assigned variable
 299      *  @param base   If the variable is referred to in a Select, the part
 300      *                to the left of the `.', null otherwise.
 301      *  @param env    The current environment.
 302      */
 303     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 304         if (v.name == names._this) {
 305             log.error(pos, Errors.CantAssignValToThis);
 306             return;
 307         }
 308         if ((v.flags() & FINAL) != 0 &&
 309             ((v.flags() & HASINIT) != 0
 310              ||
 311              !((base == null ||
 312                TreeInfo.isThisQualifier(base)) &&
 313                isAssignableAsBlankFinal(v, env)))) {
 314             if (v.isResourceVariable()) { //TWR resource
 315                 log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
 316             } else {
 317                 log.error(pos, Errors.CantAssignValToVar(Flags.toSource(v.flags() & (STATIC | FINAL)), v));
 318             }
 319             return;
 320         }
 321     }
 322 
 323     /** Does tree represent a static reference to an identifier?
 324      *  It is assumed that tree is either a SELECT or an IDENT.
 325      *  We have to weed out selects from non-type names here.
 326      *  @param tree    The candidate tree.
 327      */
 328     boolean isStaticReference(JCTree tree) {
 329         if (tree.hasTag(SELECT)) {
 330             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 331             if (lsym == null || lsym.kind != TYP) {
 332                 return false;
 333             }
 334         }
 335         return true;
 336     }
 337 
 338     /** Is this symbol a type?
 339      */
 340     static boolean isType(Symbol sym) {
 341         return sym != null && sym.kind == TYP;
 342     }
 343 
 344     /** Attribute a parsed identifier.
 345      * @param tree Parsed identifier name
 346      * @param topLevel The toplevel to use
 347      */
 348     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 349         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 350         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 351                                            syms.errSymbol.name,
 352                                            null, null, null, null);
 353         localEnv.enclClass.sym = syms.errSymbol;
 354         return attribIdent(tree, localEnv);
 355     }
 356 
 357     /** Attribute a parsed identifier.
 358      * @param tree Parsed identifier name
 359      * @param env The env to use
 360      */
 361     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 362         return tree.accept(identAttributer, env);
 363     }
 364     // where
 365         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 366         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 367             @Override @DefinedBy(Api.COMPILER_TREE)
 368             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 369                 Symbol site = visit(node.getExpression(), env);
 370                 if (site == null || site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 371                     return site;
 372                 Name name = (Name)node.getIdentifier();
 373                 if (site.kind == PCK) {
 374                     env.toplevel.packge = (PackageSymbol)site;
 375                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 376                             KindSelector.TYP_PCK);
 377                 } else {
 378                     env.enclClass.sym = (ClassSymbol)site;
 379                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 380                 }
 381             }
 382 
 383             @Override @DefinedBy(Api.COMPILER_TREE)
 384             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 385                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 386             }
 387         }
 388 
 389     public Type coerce(Type etype, Type ttype) {
 390         return cfolder.coerce(etype, ttype);
 391     }
 392 
 393     public Type attribType(JCTree node, TypeSymbol sym) {
 394         Env<AttrContext> env = typeEnvs.get(sym);
 395         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 396         return attribTree(node, localEnv, unknownTypeInfo);
 397     }
 398 
 399     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 400         // Attribute qualifying package or class.
 401         JCFieldAccess s = tree.qualid;
 402         return attribTree(s.selected, env,
 403                           new ResultInfo(tree.staticImport ?
 404                                          KindSelector.TYP : KindSelector.TYP_PCK,
 405                        Type.noType));
 406     }
 407 
 408     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 409         return attribToTree(expr, env, tree, unknownExprInfo);
 410     }
 411 
 412     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 413         return attribToTree(stmt, env, tree, statInfo);
 414     }
 415 
 416     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 417         breakTree = tree;
 418         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 419         try {
 420             deferredAttr.attribSpeculative(root, env, resultInfo,
 421                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 422                     argumentAttr.withLocalCacheContext());
 423             attrRecover.doRecovery();
 424         } catch (BreakAttr b) {
 425             return b.env;
 426         } catch (AssertionError ae) {
 427             if (ae.getCause() instanceof BreakAttr breakAttr) {
 428                 return breakAttr.env;
 429             } else {
 430                 throw ae;
 431             }
 432         } finally {
 433             breakTree = null;
 434             log.useSource(prev);
 435         }
 436         return env;
 437     }
 438 
 439     private JCTree breakTree = null;
 440 
 441     private static class BreakAttr extends RuntimeException {
 442         static final long serialVersionUID = -6924771130405446405L;
 443         private transient Env<AttrContext> env;
 444         private BreakAttr(Env<AttrContext> env) {
 445             this.env = env;
 446         }
 447     }
 448 
 449     /**
 450      * Mode controlling behavior of Attr.Check
 451      */
 452     enum CheckMode {
 453 
 454         NORMAL,
 455 
 456         /**
 457          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 458          * that the captured var cache in {@code InferenceContext} will be used in read-only
 459          * mode when performing inference checks.
 460          */
 461         NO_TREE_UPDATE {
 462             @Override
 463             public boolean updateTreeType() {
 464                 return false;
 465             }
 466         },
 467         /**
 468          * Mode signalling that caller will manage free types in tree decorations.
 469          */
 470         NO_INFERENCE_HOOK {
 471             @Override
 472             public boolean installPostInferenceHook() {
 473                 return false;
 474             }
 475         };
 476 
 477         public boolean updateTreeType() {
 478             return true;
 479         }
 480         public boolean installPostInferenceHook() {
 481             return true;
 482         }
 483     }
 484 
 485 
 486     class ResultInfo {
 487         final KindSelector pkind;
 488         final Type pt;
 489         final CheckContext checkContext;
 490         final CheckMode checkMode;
 491 
 492         ResultInfo(KindSelector pkind, Type pt) {
 493             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 494         }
 495 
 496         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 497             this(pkind, pt, chk.basicHandler, checkMode);
 498         }
 499 
 500         protected ResultInfo(KindSelector pkind,
 501                              Type pt, CheckContext checkContext) {
 502             this(pkind, pt, checkContext, CheckMode.NORMAL);
 503         }
 504 
 505         protected ResultInfo(KindSelector pkind,
 506                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 507             this.pkind = pkind;
 508             this.pt = pt;
 509             this.checkContext = checkContext;
 510             this.checkMode = checkMode;
 511         }
 512 
 513         /**
 514          * Should {@link Attr#attribTree} use the {@code ArgumentAttr} visitor instead of this one?
 515          * @param tree The tree to be type-checked.
 516          * @return true if {@code ArgumentAttr} should be used.
 517          */
 518         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 519 
 520         protected Type check(final DiagnosticPosition pos, final Type found) {
 521             return chk.checkType(pos, found, pt, checkContext);
 522         }
 523 
 524         protected ResultInfo dup(Type newPt) {
 525             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 526         }
 527 
 528         protected ResultInfo dup(CheckContext newContext) {
 529             return new ResultInfo(pkind, pt, newContext, checkMode);
 530         }
 531 
 532         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 533             return new ResultInfo(pkind, newPt, newContext, checkMode);
 534         }
 535 
 536         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 537             return new ResultInfo(pkind, newPt, newContext, newMode);
 538         }
 539 
 540         protected ResultInfo dup(CheckMode newMode) {
 541             return new ResultInfo(pkind, pt, checkContext, newMode);
 542         }
 543 
 544         @Override
 545         public String toString() {
 546             if (pt != null) {
 547                 return pt.toString();
 548             } else {
 549                 return "";
 550             }
 551         }
 552     }
 553 
 554     class MethodAttrInfo extends ResultInfo {
 555         public MethodAttrInfo() {
 556             this(chk.basicHandler);
 557         }
 558 
 559         public MethodAttrInfo(CheckContext checkContext) {
 560             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 561         }
 562 
 563         @Override
 564         protected boolean needsArgumentAttr(JCTree tree) {
 565             return true;
 566         }
 567 
 568         protected ResultInfo dup(Type newPt) {
 569             throw new IllegalStateException();
 570         }
 571 
 572         protected ResultInfo dup(CheckContext newContext) {
 573             return new MethodAttrInfo(newContext);
 574         }
 575 
 576         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 577             throw new IllegalStateException();
 578         }
 579 
 580         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 581             throw new IllegalStateException();
 582         }
 583 
 584         protected ResultInfo dup(CheckMode newMode) {
 585             throw new IllegalStateException();
 586         }
 587     }
 588 
 589     class RecoveryInfo extends ResultInfo {
 590 
 591         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 592             this(deferredAttrContext, Type.recoveryType);
 593         }
 594 
 595         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 596             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 597                 @Override
 598                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 599                     return deferredAttrContext;
 600                 }
 601                 @Override
 602                 public boolean compatible(Type found, Type req, Warner warn) {
 603                     return true;
 604                 }
 605                 @Override
 606                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 607                     boolean needsReport = pt == Type.recoveryType ||
 608                             (details.getDiagnosticPosition() != null &&
 609                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 610                     if (needsReport) {
 611                         chk.basicHandler.report(pos, details);
 612                     }
 613                 }
 614             });
 615         }
 616     }
 617 
 618     final ResultInfo statInfo;
 619     final ResultInfo varAssignmentInfo;
 620     final ResultInfo varAssignmentOpInfo;
 621     final ResultInfo methodAttrInfo;
 622     final ResultInfo unknownExprInfo;
 623     final ResultInfo unknownTypeInfo;
 624     final ResultInfo unknownTypeExprInfo;
 625     final ResultInfo recoveryInfo;
 626     final MethodType initBlockType;
 627 
 628     Type pt() {
 629         return resultInfo.pt;
 630     }
 631 
 632     KindSelector pkind() {
 633         return resultInfo.pkind;
 634     }
 635 
 636 /* ************************************************************************
 637  * Visitor methods
 638  *************************************************************************/
 639 
 640     /** Visitor argument: the current environment.
 641      */
 642     Env<AttrContext> env;
 643 
 644     /** Visitor argument: the currently expected attribution result.
 645      */
 646     ResultInfo resultInfo;
 647 
 648     /** Visitor result: the computed type.
 649      */
 650     Type result;
 651 
 652     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 653 
 654     /** Visitor method: attribute a tree, catching any completion failure
 655      *  exceptions. Return the tree's type.
 656      *
 657      *  @param tree    The tree to be visited.
 658      *  @param env     The environment visitor argument.
 659      *  @param resultInfo   The result info visitor argument.
 660      */
 661     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 662         Env<AttrContext> prevEnv = this.env;
 663         ResultInfo prevResult = this.resultInfo;
 664         try {
 665             this.env = env;
 666             this.resultInfo = resultInfo;
 667             if (resultInfo.needsArgumentAttr(tree)) {
 668                 result = argumentAttr.attribArg(tree, env);
 669             } else {
 670                 tree.accept(this);
 671             }
 672             matchBindings = matchBindingsComputer.finishBindings(tree,
 673                                                                  matchBindings);
 674             checkBreakTree(tree, env);
 675             return result;
 676         } catch (CompletionFailure ex) {
 677             tree.type = syms.errType;
 678             return chk.completionError(tree.pos(), ex);
 679         } finally {
 680             this.env = prevEnv;
 681             this.resultInfo = prevResult;
 682         }
 683     }
 684 
 685     private void checkBreakTree(JCTree tree, Env<AttrContext> env) {
 686         if (tree == breakTree &&
 687                 resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 688             breakTreeFound(copyEnv(env));
 689         }
 690     }
 691 
 692     protected void breakTreeFound(Env<AttrContext> env) {
 693         throw new BreakAttr(env);
 694     }
 695 
 696     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 697         Env<AttrContext> newEnv =
 698                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 699         if (newEnv.outer != null) {
 700             newEnv.outer = copyEnv(newEnv.outer);
 701         }
 702         return newEnv;
 703     }
 704 
 705     WriteableScope copyScope(WriteableScope sc) {
 706         WriteableScope newScope = WriteableScope.create(sc.owner);
 707         List<Symbol> elemsList = List.nil();
 708         for (Symbol sym : sc.getSymbols()) {
 709             elemsList = elemsList.prepend(sym);
 710         }
 711         for (Symbol s : elemsList) {
 712             newScope.enter(s);
 713         }
 714         return newScope;
 715     }
 716 
 717     /** Derived visitor method: attribute an expression tree.
 718      */
 719     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 720         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 721     }
 722 
 723     /** Derived visitor method: attribute an expression tree with
 724      *  no constraints on the computed type.
 725      */
 726     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 727         return attribTree(tree, env, unknownExprInfo);
 728     }
 729 
 730     /** Derived visitor method: attribute a type tree.
 731      */
 732     public Type attribType(JCTree tree, Env<AttrContext> env) {
 733         Type result = attribType(tree, env, Type.noType);
 734         return result;
 735     }
 736 
 737     /** Derived visitor method: attribute a type tree.
 738      */
 739     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 740         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 741         return result;
 742     }
 743 
 744     /** Derived visitor method: attribute a statement or definition tree.
 745      */
 746     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 747         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 748         Type result = attribTree(tree, env, statInfo);
 749         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 750         attrRecover.doRecovery();
 751         return result;
 752     }
 753 
 754     /** Attribute a list of expressions, returning a list of types.
 755      */
 756     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 757         ListBuffer<Type> ts = new ListBuffer<>();
 758         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 759             ts.append(attribExpr(l.head, env, pt));
 760         return ts.toList();
 761     }
 762 
 763     /** Attribute a list of statements, returning nothing.
 764      */
 765     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 766         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 767             attribStat(l.head, env);
 768     }
 769 
 770     /** Attribute the arguments in a method call, returning the method kind.
 771      */
 772     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 773         KindSelector kind = initialKind;
 774         for (JCExpression arg : trees) {
 775             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 776             if (argtype.hasTag(DEFERRED)) {
 777                 kind = KindSelector.of(KindSelector.POLY, kind);
 778             }
 779             argtypes.append(argtype);
 780         }
 781         return kind;
 782     }
 783 
 784     /** Attribute a type argument list, returning a list of types.
 785      *  Caller is responsible for calling checkRefTypes.
 786      */
 787     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 788         ListBuffer<Type> argtypes = new ListBuffer<>();
 789         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 790             argtypes.append(attribType(l.head, env));
 791         return argtypes.toList();
 792     }
 793 
 794     /** Attribute a type argument list, returning a list of types.
 795      *  Check that all the types are references.
 796      */
 797     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 798         List<Type> types = attribAnyTypes(trees, env);
 799         return chk.checkRefTypes(trees, types);
 800     }
 801 
 802     /**
 803      * Attribute type variables (of generic classes or methods).
 804      * Compound types are attributed later in attribBounds.
 805      * @param typarams the type variables to enter
 806      * @param env      the current environment
 807      */
 808     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 809         for (JCTypeParameter tvar : typarams) {
 810             TypeVar a = (TypeVar)tvar.type;
 811             a.tsym.flags_field |= UNATTRIBUTED;
 812             a.setUpperBound(Type.noType);
 813             if (!tvar.bounds.isEmpty()) {
 814                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 815                 for (JCExpression bound : tvar.bounds.tail)
 816                     bounds = bounds.prepend(attribType(bound, env));
 817                 types.setBounds(a, bounds.reverse());
 818             } else {
 819                 // if no bounds are given, assume a single bound of
 820                 // java.lang.Object.
 821                 types.setBounds(a, List.of(syms.objectType));
 822             }
 823             a.tsym.flags_field &= ~UNATTRIBUTED;
 824         }
 825         if (checkCyclic) {
 826             for (JCTypeParameter tvar : typarams) {
 827                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 828             }
 829         }
 830     }
 831 
 832     /**
 833      * Attribute the type references in a list of annotations.
 834      */
 835     void attribAnnotationTypes(List<JCAnnotation> annotations,
 836                                Env<AttrContext> env) {
 837         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 838             JCAnnotation a = al.head;
 839             attribType(a.annotationType, env);
 840         }
 841     }
 842 
 843     /**
 844      * Attribute a "lazy constant value".
 845      *  @param env         The env for the const value
 846      *  @param variable    The initializer for the const value
 847      *  @param type        The expected type, or null
 848      *  @see VarSymbol#setLazyConstValue
 849      */
 850     public Object attribLazyConstantValue(Env<AttrContext> env,
 851                                       Env<AttrContext> enclosingEnv,
 852                                       JCVariableDecl variable,
 853                                       Type type) {
 854         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 855         try {
 856             doQueueScanTreeAndTypeAnnotateForVarInit(variable, enclosingEnv);
 857             Type itype = attribExpr(variable.init, env, type);
 858             if (variable.isImplicitlyTyped()) {
 859                 //fixup local variable type
 860                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 861             }
 862             if (itype.constValue() != null) {
 863                 return coerce(itype, type).constValue();
 864             } else {
 865                 return null;
 866             }
 867         } finally {
 868             log.useSource(prevSource);
 869         }
 870     }
 871 
 872     /** Attribute type reference in an `extends', `implements', or 'permits' clause.
 873      *  Supertypes of anonymous inner classes are usually already attributed.
 874      *
 875      *  @param tree              The tree making up the type reference.
 876      *  @param env               The environment current at the reference.
 877      *  @param classExpected     true if only a class is expected here.
 878      *  @param interfaceExpected true if only an interface is expected here.
 879      */
 880     Type attribBase(JCTree tree,
 881                     Env<AttrContext> env,
 882                     boolean classExpected,
 883                     boolean interfaceExpected,
 884                     boolean checkExtensible) {
 885         Type t = tree.type != null ?
 886             tree.type :
 887             attribType(tree, env);
 888         try {
 889             return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 890         } catch (CompletionFailure ex) {
 891             chk.completionError(tree.pos(), ex);
 892             return t;
 893         }
 894     }
 895     Type checkBase(Type t,
 896                    JCTree tree,
 897                    Env<AttrContext> env,
 898                    boolean classExpected,
 899                    boolean interfaceExpected,
 900                    boolean checkExtensible) {
 901         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 902                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 903         if (t.tsym.isAnonymous()) {
 904             log.error(pos, Errors.CantInheritFromAnon);
 905             return types.createErrorType(t);
 906         }
 907         if (t.isErroneous())
 908             return t;
 909         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 910             // check that type variable is already visible
 911             if (t.getUpperBound() == null) {
 912                 log.error(pos, Errors.IllegalForwardRef);
 913                 return types.createErrorType(t);
 914             }
 915         } else {
 916             t = chk.checkClassType(pos, t, checkExtensible);
 917         }
 918         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 919             log.error(pos, Errors.IntfExpectedHere);
 920             // return errType is necessary since otherwise there might
 921             // be undetected cycles which cause attribution to loop
 922             return types.createErrorType(t);
 923         } else if (checkExtensible &&
 924                    classExpected &&
 925                    (t.tsym.flags() & INTERFACE) != 0) {
 926             log.error(pos, Errors.NoIntfExpectedHere);
 927             return types.createErrorType(t);
 928         }
 929         if (checkExtensible &&
 930             ((t.tsym.flags() & FINAL) != 0)) {
 931             log.error(pos,
 932                       Errors.CantInheritFromFinal(t.tsym));
 933         }
 934         chk.checkNonCyclic(pos, t);
 935         return t;
 936     }
 937 
 938     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 939         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 940         id.type = env.info.scope.owner.enclClass().type;
 941         id.sym = env.info.scope.owner.enclClass();
 942         return id.type;
 943     }
 944 
 945     public void visitClassDef(JCClassDecl tree) {
 946         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 947                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 948                         argumentAttr.withLocalCacheContext() : null);
 949         EarlyConstructionContext earlyConstructionPrev = env.info.earlyContext;
 950         try {
 951             env.info.earlyContext = earlyConstructionPrev.nested(true);
 952             // Local and anonymous classes have not been entered yet, so we need to
 953             // do it now.
 954             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 955                 enter.classEnter(tree, env);
 956             } else {
 957                 // If this class declaration is part of a class level annotation,
 958                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 959                 // order to simplify later steps and allow for sensible error
 960                 // messages.
 961                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 962                     enter.classEnter(tree, env);
 963             }
 964 
 965             ClassSymbol c = tree.sym;
 966             if (c == null) {
 967                 // exit in case something drastic went wrong during enter.
 968                 result = null;
 969             } else {
 970                 // make sure class has been completed:
 971                 c.complete();
 972 
 973                 // If a class declaration appears in a constructor prologue,
 974                 // that means it's either a local class or an anonymous class.
 975                 // Either way, there is no immediately enclosing instance.
 976                 if (earlyConstructionPrev.ctorPrologue()) {
 977                     c.flags_field |= NOOUTERTHIS;
 978                 }
 979                 attribClass(tree.pos(), c);
 980                 result = tree.type = c.type;
 981             }
 982         } finally {
 983             localCacheContext.ifPresent(LocalCacheContext::leave);
 984             env.info.earlyContext = earlyConstructionPrev;
 985         }
 986     }
 987 
 988     public void visitMethodDef(JCMethodDecl tree) {
 989         MethodSymbol m = tree.sym;
 990         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
 991 
 992         Lint lint = env.info.lint.augment(m);
 993         Lint prevLint = chk.setLint(lint);
 994         EarlyConstructionContext earlyConstructionPrev = env.info.earlyContext;
 995         Assert.check(!earlyConstructionPrev.ctorPrologue());
 996         MethodSymbol prevMethod = chk.setMethod(m);
 997         try {
 998             chk.checkDeprecatedAnnotation(tree.pos(), m);
 999 
1000 
1001             // Create a new environment with local scope
1002             // for attributing the method.
1003             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
1004             localEnv.info.lint = lint;
1005 
1006             attribStats(tree.typarams, localEnv);
1007 
1008             // If we override any other methods, check that we do so properly.
1009             // JLS ???
1010             if (m.isStatic()) {
1011                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1012             } else {
1013                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1014             }
1015             chk.checkOverride(env, tree, m);
1016 
1017             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1018                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1019             }
1020 
1021             // Enter all type parameters into the local method scope.
1022             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1023                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1024 
1025             ClassSymbol owner = env.enclClass.sym;
1026             if ((owner.flags() & ANNOTATION) != 0 &&
1027                     (tree.params.nonEmpty() ||
1028                     tree.recvparam != null))
1029                 log.error(tree.params.nonEmpty() ?
1030                         tree.params.head.pos() :
1031                         tree.recvparam.pos(),
1032                         Errors.IntfAnnotationMembersCantHaveParams);
1033 
1034             // Attribute all value parameters.
1035             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1036                 attribStat(l.head, localEnv);
1037             }
1038 
1039             chk.checkVarargsMethodDecl(localEnv, tree);
1040 
1041             // Check that type parameters are well-formed.
1042             chk.validate(tree.typarams, localEnv);
1043 
1044             // Check that result type is well-formed.
1045             if (tree.restype != null && !tree.restype.type.hasTag(VOID)) {
1046                 chk.validate(tree.restype, localEnv);
1047             }
1048             chk.checkRequiresIdentity(tree, env.info.lint);
1049 
1050             // Check that receiver type is well-formed.
1051             if (tree.recvparam != null) {
1052                 // Use a new environment to check the receiver parameter.
1053                 // Otherwise I get "might not have been initialized" errors.
1054                 // Is there a better way?
1055                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1056                 attribType(tree.recvparam, newEnv);
1057                 chk.validate(tree.recvparam, newEnv);
1058             }
1059 
1060             // Is this method a constructor?
1061             boolean isConstructor = TreeInfo.isConstructor(tree);
1062 
1063             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1064                 // lets find if this method is an accessor
1065                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1066                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1067                 if (recordComponent.isPresent()) {
1068                     // the method is a user defined accessor lets check that everything is fine
1069                     if (!tree.sym.isPublic()) {
1070                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1071                     }
1072                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1073                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1074                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1075                     }
1076                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1077                         log.error(tree,
1078                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1079                     }
1080                     if (!tree.typarams.isEmpty()) {
1081                         log.error(tree,
1082                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1083                     }
1084                     if (tree.sym.isStatic()) {
1085                         log.error(tree,
1086                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1087                     }
1088                 }
1089 
1090                 if (isConstructor) {
1091                     // if this a constructor other than the canonical one
1092                     if ((tree.sym.flags_field & RECORD) == 0) {
1093                         if (!TreeInfo.hasConstructorCall(tree, names._this)) {
1094                             log.error(tree, Errors.NonCanonicalConstructorInvokeAnotherConstructor(env.enclClass.sym));
1095                         }
1096                     } else {
1097                         // but if it is the canonical:
1098 
1099                         /* if user generated, then it shouldn't:
1100                          *     - have an accessibility stricter than that of the record type
1101                          *     - explicitly invoke any other constructor
1102                          */
1103                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1104                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1105                                 log.error(tree,
1106                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1107                                             Errors.InvalidCanonicalConstructorInRecord(
1108                                                 Fragments.Canonical,
1109                                                 env.enclClass.sym.name,
1110                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1111                                             ) :
1112                                             Errors.InvalidCanonicalConstructorInRecord(
1113                                                     Fragments.Canonical,
1114                                                     env.enclClass.sym.name,
1115                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1116                                             )
1117                                 );
1118                             }
1119 
1120                             if ((!allowValueClasses || TreeInfo.isCompactConstructor(tree)) &&
1121                                     TreeInfo.hasAnyConstructorCall(tree)) {
1122                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1123                                         Fragments.Canonical, env.enclClass.sym.name,
1124                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1125                             }
1126                         }
1127 
1128                         // also we want to check that no type variables have been defined
1129                         if (!tree.typarams.isEmpty()) {
1130                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1131                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1132                         }
1133 
1134                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1135                          * record components
1136                          */
1137                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1138                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1139                         for (JCVariableDecl param: tree.params) {
1140                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1141                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1142                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1143                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1144                                         Fragments.Canonical, env.enclClass.sym.name,
1145                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1146                             }
1147                             recordComponents = recordComponents.tail;
1148                             recordFieldTypes = recordFieldTypes.tail;
1149                         }
1150                     }
1151                 }
1152             }
1153 
1154             // annotation method checks
1155             if ((owner.flags() & ANNOTATION) != 0) {
1156                 // annotation method cannot have throws clause
1157                 if (tree.thrown.nonEmpty()) {
1158                     log.error(tree.thrown.head.pos(),
1159                               Errors.ThrowsNotAllowedInIntfAnnotation);
1160                 }
1161                 // annotation method cannot declare type-parameters
1162                 if (tree.typarams.nonEmpty()) {
1163                     log.error(tree.typarams.head.pos(),
1164                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1165                 }
1166                 // validate annotation method's return type (could be an annotation type)
1167                 chk.validateAnnotationType(tree.restype);
1168                 // ensure that annotation method does not clash with members of Object/Annotation
1169                 chk.validateAnnotationMethod(tree.pos(), m);
1170             }
1171 
1172             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1173                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1174 
1175             if (tree.body == null) {
1176                 // Empty bodies are only allowed for
1177                 // abstract, native, or interface methods, or for methods
1178                 // in a retrofit signature class.
1179                 if (tree.defaultValue != null) {
1180                     if ((owner.flags() & ANNOTATION) == 0)
1181                         log.error(tree.pos(),
1182                                   Errors.DefaultAllowedInIntfAnnotationMember);
1183                 }
1184                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1185                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract(tree.sym, owner));
1186             } else {
1187                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1188                     if ((owner.flags() & INTERFACE) != 0) {
1189                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1190                     } else {
1191                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1192                     }
1193                 } else if ((tree.mods.flags & NATIVE) != 0) {
1194                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1195                 }
1196                 // Add an implicit super() call unless an explicit call to
1197                 // super(...) or this(...) is given
1198                 // or we are compiling class java.lang.Object.
1199                 boolean addedSuperInIdentityClass = false;
1200                 if (isConstructor && owner.type != syms.objectType) {
1201                     if (!TreeInfo.hasAnyConstructorCall(tree)) {
1202                         JCStatement supCall = make.at(tree.body.pos).Exec(make.Apply(List.nil(),
1203                                 make.Ident(names._super), make.Idents(List.nil())));
1204                         if (allowValueClasses && (owner.isValueClass() || owner.isRecord())) {
1205                             tree.body.stats = tree.body.stats.append(supCall);
1206                         } else {
1207                             tree.body.stats = tree.body.stats.prepend(supCall);
1208                             addedSuperInIdentityClass = true;
1209                         }
1210                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1211                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1212                             TreeInfo.hasConstructorCall(tree, names._super)) {
1213                         // enum constructors are not allowed to call super
1214                         // directly, so make sure there aren't any super calls
1215                         // in enum constructors, except in the compiler
1216                         // generated one.
1217                         log.error(tree.body.stats.head.pos(),
1218                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1219                     }
1220                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1221                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1222                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1223                         if (!initParamNames.equals(recordComponentNames)) {
1224                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1225                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1226                         }
1227                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1228                             log.error(tree,
1229                                     Errors.InvalidCanonicalConstructorInRecord(
1230                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1231                                             env.enclClass.sym.name,
1232                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1233                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1234                         }
1235                     }
1236                 }
1237 
1238                 // Attribute all type annotations in the body
1239                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m);
1240                 annotate.flush();
1241 
1242                 // Start of constructor prologue (if not in java.lang.Object constructor)
1243                 if (isConstructor && owner.type != syms.objectType) {
1244                     boolean hasThisConstructorCall = TreeInfo.hasConstructorCall(tree, names._this);
1245                     localEnv.info.earlyContext = EarlyConstructionContext.of(owner,
1246                             addedSuperInIdentityClass && allowValueClasses,
1247                             hasThisConstructorCall && allowValueClasses);
1248                 }
1249 
1250                 // Attribute method body.
1251                 attribStat(tree.body, localEnv);
1252             }
1253 
1254             localEnv.info.scope.leave();
1255             result = tree.type = m.type;
1256         } finally {
1257             chk.setLint(prevLint);
1258             chk.setMethod(prevMethod);
1259             env.info.earlyContext = earlyConstructionPrev;
1260         }
1261     }
1262 
1263     public void visitVarDef(JCVariableDecl tree) {
1264         // Local variables have not been entered yet, so we need to do it now:
1265         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1266             if (tree.sym != null) {
1267                 // parameters have already been entered
1268                 env.info.scope.enter(tree.sym);
1269             } else {
1270                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0 && tree.type == null) {
1271                     if (tree.init == null) {
1272                         //cannot use 'var' without initializer
1273                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1274                         tree.type = syms.errType;
1275                     } else {
1276                         Fragment msg = canInferLocalVarType(tree);
1277                         if (msg != null) {
1278                             //cannot use 'var' with initializer which require an explicit target
1279                             //(e.g. lambda, method reference, array initializer).
1280                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1281                             tree.type = syms.errType;
1282                         }
1283                     }
1284                 }
1285                 try {
1286                     annotate.blockAnnotations();
1287                     memberEnter.memberEnter(tree, env);
1288                     typeAnnotations.organizeTypeAnnotationsSignaturesForLocalVarType(env, tree);
1289                 } finally {
1290                     annotate.unblockAnnotations();
1291                 }
1292             }
1293         } else {
1294             doQueueScanTreeAndTypeAnnotateForVarInit(tree, env);
1295         }
1296 
1297         VarSymbol v = tree.sym;
1298         Lint lint = env.info.lint.augment(v);
1299         Lint prevLint = chk.setLint(lint);
1300 
1301         // Check that the variable's declared type is well-formed.
1302         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1303                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1304                 (tree.sym.flags() & PARAMETER) != 0;
1305         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1306 
1307         try {
1308             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1309             chk.checkDeprecatedAnnotation(tree.pos(), v);
1310 
1311             if (tree.init != null) {
1312                 if ((v.flags_field & FINAL) == 0 ||
1313                     !memberEnter.needsLazyConstValue(tree.init)) {
1314                     // Not a compile-time constant
1315                     // Attribute initializer in a new environment
1316                     // with the declared variable as owner.
1317                     // Check that initializer conforms to variable's declared type.
1318                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
1319                     initEnv.info.lint = lint;
1320                     // In order to catch self-references, we set the variable's
1321                     // declaration position to maximal possible value, effectively
1322                     // marking the variable as undefined.
1323                     initEnv.info.enclVar = v;
1324                     EarlyConstructionContext previousEarlyConstruction = initEnv.info.earlyContext;
1325                     try {
1326                         if (v.owner.kind == TYP && !v.isStatic() && allowValueClasses) {
1327                             // instance strict field init occur in early construction context
1328                             initEnv.info.earlyContext = EarlyConstructionContext.of((ClassSymbol)v.owner,
1329                                     !v.isStrict(), false);
1330                         }
1331                         attribExpr(tree.init, initEnv, v.type);
1332                         if (tree.isImplicitlyTyped()) {
1333                             //fixup local variable type
1334                             v.type = chk.checkLocalVarType(tree, tree.init.type, tree.name);
1335                         }
1336                     } finally {
1337                         initEnv.info.earlyContext = previousEarlyConstruction;
1338                     }
1339                 }
1340                 if (tree.isImplicitlyTyped()) {
1341                     setupImplicitlyTypedVariable(tree, v.type);
1342                 }
1343             }
1344             result = tree.type = v.type;
1345             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
1346                 if (isNonArgsMethodInObject(v.name)) {
1347                     log.error(tree, Errors.IllegalRecordComponentName(v));
1348                 }
1349             }
1350             chk.checkRequiresIdentity(tree, env.info.lint);
1351         }
1352         finally {
1353             chk.setLint(prevLint);
1354         }
1355     }
1356 
1357     private void doQueueScanTreeAndTypeAnnotateForVarInit(JCVariableDecl tree, Env<AttrContext> env) {
1358         if (tree.init != null &&
1359             (tree.sym.flags_field & Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED) == 0 &&
1360             env.info.scope.owner.kind != MTH && env.info.scope.owner.kind != VAR) {
1361             tree.sym.flags_field |= Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED;
1362             // Field initializer expression need to be entered.
1363             annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym);
1364             annotate.flush();
1365         }
1366     }
1367 
1368     private boolean isNonArgsMethodInObject(Name name) {
1369         for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
1370             if (s.type.getParameterTypes().isEmpty()) {
1371                 return true;
1372             }
1373         }
1374         return false;
1375     }
1376 
1377     Fragment canInferLocalVarType(JCVariableDecl tree) {
1378         LocalInitScanner lis = new LocalInitScanner();
1379         lis.scan(tree.init);
1380         return lis.badInferenceMsg;
1381     }
1382 
1383     static class LocalInitScanner extends TreeScanner {
1384         Fragment badInferenceMsg = null;
1385         boolean needsTarget = true;
1386 
1387         @Override
1388         public void visitNewArray(JCNewArray tree) {
1389             if (tree.elemtype == null && needsTarget) {
1390                 badInferenceMsg = Fragments.LocalArrayMissingTarget;
1391             }
1392         }
1393 
1394         @Override
1395         public void visitLambda(JCLambda tree) {
1396             if (needsTarget) {
1397                 badInferenceMsg = Fragments.LocalLambdaMissingTarget;
1398             }
1399         }
1400 
1401         @Override
1402         public void visitTypeCast(JCTypeCast tree) {
1403             boolean prevNeedsTarget = needsTarget;
1404             try {
1405                 needsTarget = false;
1406                 super.visitTypeCast(tree);
1407             } finally {
1408                 needsTarget = prevNeedsTarget;
1409             }
1410         }
1411 
1412         @Override
1413         public void visitReference(JCMemberReference tree) {
1414             if (needsTarget) {
1415                 badInferenceMsg = Fragments.LocalMrefMissingTarget;
1416             }
1417         }
1418 
1419         @Override
1420         public void visitNewClass(JCNewClass tree) {
1421             boolean prevNeedsTarget = needsTarget;
1422             try {
1423                 needsTarget = false;
1424                 super.visitNewClass(tree);
1425             } finally {
1426                 needsTarget = prevNeedsTarget;
1427             }
1428         }
1429 
1430         @Override
1431         public void visitApply(JCMethodInvocation tree) {
1432             boolean prevNeedsTarget = needsTarget;
1433             try {
1434                 needsTarget = false;
1435                 super.visitApply(tree);
1436             } finally {
1437                 needsTarget = prevNeedsTarget;
1438             }
1439         }
1440     }
1441 
1442     public void visitSkip(JCSkip tree) {
1443         result = null;
1444     }
1445 
1446     public void visitBlock(JCBlock tree) {
1447         if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
1448             // Block is a static or instance initializer;
1449             // let the owner of the environment be a freshly
1450             // created BLOCK-method.
1451             Symbol fakeOwner =
1452                 new MethodSymbol(tree.flags | BLOCK |
1453                     env.info.scope.owner.flags() & STRICTFP, names.empty, initBlockType,
1454                     env.info.scope.owner);
1455             final Env<AttrContext> localEnv =
1456                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
1457 
1458             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
1459             // Attribute all type annotations in the block
1460             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner);
1461             annotate.flush();
1462             attribStats(tree.stats, localEnv);
1463 
1464             {
1465                 // Store init and clinit type annotations with the ClassSymbol
1466                 // to allow output in Gen.normalizeDefs.
1467                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1468                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1469                 if ((tree.flags & STATIC) != 0) {
1470                     cs.appendClassInitTypeAttributes(tas);
1471                 } else {
1472                     cs.appendInitTypeAttributes(tas);
1473                 }
1474             }
1475         } else {
1476             // Create a new local environment with a local scope.
1477             Env<AttrContext> localEnv =
1478                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1479             try {
1480                 attribStats(tree.stats, localEnv);
1481             } finally {
1482                 localEnv.info.scope.leave();
1483             }
1484         }
1485         result = null;
1486     }
1487 
1488     public void visitDoLoop(JCDoWhileLoop tree) {
1489         attribStat(tree.body, env.dup(tree));
1490         attribExpr(tree.cond, env, syms.booleanType);
1491         handleLoopConditionBindings(matchBindings, tree, tree.body);
1492         result = null;
1493     }
1494 
1495     public void visitWhileLoop(JCWhileLoop tree) {
1496         attribExpr(tree.cond, env, syms.booleanType);
1497         MatchBindings condBindings = matchBindings;
1498         // include condition's bindings when true in the body:
1499         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1500         try {
1501             attribStat(tree.body, whileEnv.dup(tree));
1502         } finally {
1503             whileEnv.info.scope.leave();
1504         }
1505         handleLoopConditionBindings(condBindings, tree, tree.body);
1506         result = null;
1507     }
1508 
1509     public void visitForLoop(JCForLoop tree) {
1510         Env<AttrContext> loopEnv =
1511             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1512         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1513         try {
1514             attribStats(tree.init, loopEnv);
1515             if (tree.cond != null) {
1516                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1517                 // include condition's bindings when true in the body and step:
1518                 condBindings = matchBindings;
1519             }
1520             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1521             try {
1522                 bodyEnv.tree = tree; // before, we were not in loop!
1523                 attribStats(tree.step, bodyEnv);
1524                 attribStat(tree.body, bodyEnv);
1525             } finally {
1526                 bodyEnv.info.scope.leave();
1527             }
1528             result = null;
1529         }
1530         finally {
1531             loopEnv.info.scope.leave();
1532         }
1533         handleLoopConditionBindings(condBindings, tree, tree.body);
1534     }
1535 
1536     /**
1537      * Include condition's bindings when false after the loop, if cannot get out of the loop
1538      */
1539     private void handleLoopConditionBindings(MatchBindings condBindings,
1540                                              JCStatement loop,
1541                                              JCStatement loopBody) {
1542         if (condBindings.bindingsWhenFalse.nonEmpty() &&
1543             !breaksTo(env, loop, loopBody)) {
1544             addBindings2Scope(loop, condBindings.bindingsWhenFalse);
1545         }
1546     }
1547 
1548     private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
1549         preFlow(body);
1550         return flow.breaksToTree(env, loop, body, make);
1551     }
1552 
1553     /**
1554      * Add given bindings to the current scope, unless there's a break to
1555      * an immediately enclosing labeled statement.
1556      */
1557     private void addBindings2Scope(JCStatement introducingStatement,
1558                                    List<BindingSymbol> bindings) {
1559         if (bindings.isEmpty()) {
1560             return ;
1561         }
1562 
1563         var searchEnv = env;
1564         while (searchEnv.tree instanceof JCLabeledStatement labeled &&
1565                labeled.body == introducingStatement) {
1566             if (breaksTo(env, labeled, labeled.body)) {
1567                 //breaking to an immediately enclosing labeled statement
1568                 return ;
1569             }
1570             searchEnv = searchEnv.next;
1571             introducingStatement = labeled;
1572         }
1573 
1574         //include condition's body when false after the while, if cannot get out of the loop
1575         bindings.forEach(env.info.scope::enter);
1576         bindings.forEach(BindingSymbol::preserveBinding);
1577     }
1578 
1579     public void visitForeachLoop(JCEnhancedForLoop tree) {
1580         Env<AttrContext> loopEnv =
1581             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1582         try {
1583             //the Formal Parameter of a for-each loop is not in the scope when
1584             //attributing the for-each expression; we mimic this by attributing
1585             //the for-each expression first (against original scope).
1586             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1587             chk.checkNonVoid(tree.pos(), exprType);
1588             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1589             if (elemtype == null) {
1590                 // or perhaps expr implements Iterable<T>?
1591                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1592                 if (base == null) {
1593                     log.error(tree.expr.pos(),
1594                               Errors.ForeachNotApplicableToType(exprType,
1595                                                                 Fragments.TypeReqArrayOrIterable));
1596                     elemtype = types.createErrorType(exprType);
1597                 } else {
1598                     List<Type> iterableParams = base.allparams();
1599                     elemtype = iterableParams.isEmpty()
1600                         ? syms.objectType
1601                         : types.wildUpperBound(iterableParams.head);
1602 
1603                     // Check the return type of the method iterator().
1604                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1605                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1606                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1607                     if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
1608                         log.error(tree.pos(),
1609                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1610                     }
1611                 }
1612             }
1613             if (tree.var.isImplicitlyTyped()) {
1614                 Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
1615                 tree.var.type = inferredType;
1616                 setupImplicitlyTypedVariable(tree.var, inferredType);
1617             }
1618             attribStat(tree.var, loopEnv);
1619             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1620             loopEnv.tree = tree; // before, we were not in loop!
1621             attribStat(tree.body, loopEnv);
1622             result = null;
1623         }
1624         finally {
1625             loopEnv.info.scope.leave();
1626         }
1627     }
1628 
1629     public void visitLabelled(JCLabeledStatement tree) {
1630         // Check that label is not used in an enclosing statement
1631         Env<AttrContext> env1 = env;
1632         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1633             if (env1.tree.hasTag(LABELLED) &&
1634                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1635                 log.error(tree.pos(),
1636                           Errors.LabelAlreadyInUse(tree.label));
1637                 break;
1638             }
1639             env1 = env1.next;
1640         }
1641 
1642         attribStat(tree.body, env.dup(tree));
1643         result = null;
1644     }
1645 
1646     public void visitSwitch(JCSwitch tree) {
1647         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1648             attribStats(c.stats, caseEnv);
1649         });
1650         result = null;
1651     }
1652 
1653     public void visitSwitchExpression(JCSwitchExpression tree) {
1654         boolean wrongContext = false;
1655 
1656         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
1657                 PolyKind.STANDALONE : PolyKind.POLY;
1658 
1659         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
1660             //this means we are returning a poly conditional from void-compatible lambda expression
1661             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
1662             resultInfo = recoveryInfo;
1663             wrongContext = true;
1664         }
1665 
1666         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
1667                 unknownExprInfo :
1668                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
1669 
1670         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
1671         ListBuffer<Type> caseTypes = new ListBuffer<>();
1672 
1673         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1674             caseEnv.info.yieldResult = condInfo;
1675             attribStats(c.stats, caseEnv);
1676             new TreeScanner() {
1677                 @Override
1678                 public void visitYield(JCYield brk) {
1679                     if (brk.target == tree) {
1680                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
1681                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
1682                     }
1683                     super.visitYield(brk);
1684                 }
1685 
1686                 @Override public void visitClassDef(JCClassDecl tree) {}
1687                 @Override public void visitLambda(JCLambda tree) {}
1688             }.scan(c.stats);
1689         });
1690 
1691         if (tree.cases.isEmpty()) {
1692             log.error(tree.pos(),
1693                       Errors.SwitchExpressionEmpty);
1694         } else if (caseTypes.isEmpty()) {
1695             log.error(tree.pos(),
1696                       Errors.SwitchExpressionNoResultExpressions);
1697         }
1698 
1699         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
1700 
1701         result = tree.type = wrongContext? types.createErrorType(pt()) : check(tree, owntype, KindSelector.VAL, resultInfo);
1702     }
1703     //where:
1704         CheckContext switchExpressionContext(CheckContext checkContext) {
1705             return new Check.NestedCheckContext(checkContext) {
1706                 //this will use enclosing check context to check compatibility of
1707                 //subexpression against target type; if we are in a method check context,
1708                 //depending on whether boxing is allowed, we could have incompatibilities
1709                 @Override
1710                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1711                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
1712                 }
1713             };
1714         }
1715 
1716     private void handleSwitch(JCTree switchTree,
1717                               JCExpression selector,
1718                               List<JCCase> cases,
1719                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
1720         Type seltype = attribExpr(selector, env);
1721         Type seltypeUnboxed = types.unboxedTypeOrType(seltype);
1722 
1723         Env<AttrContext> switchEnv =
1724             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
1725 
1726         try {
1727             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
1728             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
1729             boolean booleanSwitch = types.isSameType(seltypeUnboxed, syms.booleanType);
1730             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
1731             boolean intSwitch = types.isAssignable(seltype, syms.intType);
1732             boolean patternSwitch;
1733             if (seltype.isPrimitive() && !intSwitch) {
1734                 preview.checkSourceLevel(selector.pos(), Feature.PRIMITIVE_PATTERNS);
1735                 patternSwitch = true;
1736             }
1737             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
1738                 !intSwitch) {
1739                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
1740                 patternSwitch = true;
1741             } else {
1742                 patternSwitch = cases.stream()
1743                                      .flatMap(c -> c.labels.stream())
1744                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
1745                                                     TreeInfo.isNullCaseLabel(l));
1746             }
1747 
1748             // Attribute all cases and
1749             // check that there are no duplicate case labels or default clauses.
1750             Set<Object> constants = new HashSet<>(); // The set of case constants.
1751             boolean hasDefault = false;           // Is there a default label?
1752             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
1753             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
1754             boolean hasNullPattern = false;       // Is there a null pattern?
1755             CaseTree.CaseKind caseKind = null;
1756             boolean wasError = false;
1757             JCCaseLabel unconditionalCaseLabel = null;
1758             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
1759                 JCCase c = l.head;
1760                 if (caseKind == null) {
1761                     caseKind = c.caseKind;
1762                 } else if (caseKind != c.caseKind && !wasError) {
1763                     log.error(c.pos(),
1764                               Errors.SwitchMixingCaseTypes);
1765                     wasError = true;
1766                 }
1767                 MatchBindings currentBindings = null;
1768                 MatchBindings guardBindings = null;
1769                 for (List<JCCaseLabel> labels = c.labels; labels.nonEmpty(); labels = labels.tail) {
1770                     JCCaseLabel label = labels.head;
1771                     if (label instanceof JCConstantCaseLabel constLabel) {
1772                         JCExpression expr = constLabel.expr;
1773                         if (TreeInfo.isNull(expr)) {
1774                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
1775                             if (hasNullPattern) {
1776                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1777                             }
1778                             hasNullPattern = true;
1779                             attribExpr(expr, switchEnv, seltype);
1780                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
1781                         } else if (enumSwitch) {
1782                             Symbol sym = enumConstant(expr, seltype);
1783                             if (sym == null) {
1784                                 if (allowPatternSwitch) {
1785                                     attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1786                                     Symbol enumSym = TreeInfo.symbol(expr);
1787                                     if (enumSym == null || !enumSym.isEnum() || enumSym.kind != VAR) {
1788                                         log.error(expr.pos(), Errors.EnumLabelMustBeEnumConstant);
1789                                     } else if (!constants.add(enumSym)) {
1790                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1791                                     }
1792                                 } else {
1793                                     log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
1794                                 }
1795                             } else if (!constants.add(sym)) {
1796                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1797                             }
1798                         } else if (errorEnumSwitch) {
1799                             //error recovery: the selector is erroneous, and all the case labels
1800                             //are identifiers. This could be an enum switch - don't report resolve
1801                             //error for the case label:
1802                             var prevResolveHelper = rs.basicLogResolveHelper;
1803                             try {
1804                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
1805                                 attribExpr(expr, switchEnv, seltype);
1806                             } finally {
1807                                 rs.basicLogResolveHelper = prevResolveHelper;
1808                             }
1809                         } else {
1810                             Type pattype = attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1811                             if (!pattype.hasTag(ERROR)) {
1812                                 if (pattype.constValue() == null) {
1813                                     Symbol s = TreeInfo.symbol(expr);
1814                                     if (s != null && s.kind == TYP) {
1815                                         log.error(expr.pos(),
1816                                                   Errors.PatternExpected);
1817                                     } else if (s == null || !s.isEnum()) {
1818                                         log.error(expr.pos(),
1819                                                   (stringSwitch ? Errors.StringConstReq
1820                                                                 : intSwitch ? Errors.ConstExprReq
1821                                                                             : Errors.PatternOrEnumReq));
1822                                     } else if (!constants.add(s)) {
1823                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1824                                     }
1825                                 }
1826                                 else {
1827                                     boolean isLongFloatDoubleOrBooleanConstant =
1828                                             pattype.getTag().isInSuperClassesOf(LONG) || pattype.getTag().equals(BOOLEAN);
1829                                     if (isLongFloatDoubleOrBooleanConstant) {
1830                                         preview.checkSourceLevel(label.pos(), Feature.PRIMITIVE_PATTERNS);
1831                                     }
1832                                     if (!stringSwitch && !intSwitch && !(isLongFloatDoubleOrBooleanConstant && types.isSameType(seltypeUnboxed, pattype))) {
1833                                         log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
1834                                     } else if (!constants.add(pattype.constValue())) {
1835                                         log.error(c.pos(), Errors.DuplicateCaseLabel);
1836                                     }
1837                                 }
1838                             }
1839                         }
1840                     } else if (label instanceof JCDefaultCaseLabel def) {
1841                         if (hasDefault) {
1842                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
1843                         } else if (hasUnconditionalPattern) {
1844                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
1845                         }  else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1846                             log.error(label.pos(), Errors.DefaultAndBothBooleanValues);
1847                         }
1848                         hasDefault = true;
1849                         matchBindings = MatchBindingsComputer.EMPTY;
1850                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
1851                         //pattern
1852                         JCPattern pat = patternlabel.pat;
1853                         attribExpr(pat, switchEnv, seltype);
1854                         Type primaryType = TreeInfo.primaryPatternType(pat);
1855 
1856                         if (primaryType.isPrimitive()) {
1857                             preview.checkSourceLevel(pat.pos(), Feature.PRIMITIVE_PATTERNS);
1858                         } else if (!primaryType.hasTag(TYPEVAR)) {
1859                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
1860                         }
1861                         checkCastablePattern(pat.pos(), seltype, primaryType);
1862                         Type patternType = types.erasure(primaryType);
1863                         JCExpression guard = c.guard;
1864                         if (guardBindings == null && guard != null) {
1865                             MatchBindings afterPattern = matchBindings;
1866                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
1867                             try {
1868                                 attribExpr(guard, bodyEnv, syms.booleanType);
1869                             } finally {
1870                                 bodyEnv.info.scope.leave();
1871                             }
1872 
1873                             guardBindings = matchBindings;
1874                             matchBindings = afterPattern;
1875 
1876                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
1877                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
1878                             }
1879                         }
1880                         boolean unguarded = TreeInfo.unguardedCase(c) && !pat.hasTag(RECORDPATTERN);
1881                         boolean unconditional =
1882                                 unguarded &&
1883                                 !patternType.isErroneous() &&
1884                                 types.isUnconditionallyExactTypeBased(seltype, patternType);
1885                         if (unconditional) {
1886                             if (hasUnconditionalPattern) {
1887                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
1888                             } else if (hasDefault) {
1889                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
1890                             } else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1891                                 log.error(pat.pos(), Errors.UnconditionalPatternAndBothBooleanValues);
1892                             }
1893                             hasUnconditionalPattern = true;
1894                             unconditionalCaseLabel = label;
1895                         }
1896                         lastPatternErroneous = patternType.isErroneous();
1897                     } else {
1898                         Assert.error();
1899                     }
1900                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
1901                 }
1902 
1903                 if (guardBindings != null) {
1904                     currentBindings = matchBindingsComputer.caseGuard(c, currentBindings, guardBindings);
1905                 }
1906 
1907                 Env<AttrContext> caseEnv =
1908                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
1909                 try {
1910                     attribCase.accept(c, caseEnv);
1911                 } finally {
1912                     caseEnv.info.scope.leave();
1913                 }
1914                 addVars(c.stats, switchEnv.info.scope);
1915 
1916                 preFlow(c);
1917                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
1918             }
1919             if (patternSwitch) {
1920                 chk.checkSwitchCaseStructure(cases);
1921                 chk.checkSwitchCaseLabelDominated(unconditionalCaseLabel, cases);
1922             }
1923             if (switchTree.hasTag(SWITCH)) {
1924                 ((JCSwitch) switchTree).hasUnconditionalPattern =
1925                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1926                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
1927             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
1928                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
1929                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1930                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
1931             } else {
1932                 Assert.error(switchTree.getTag().name());
1933             }
1934         } finally {
1935             switchEnv.info.scope.leave();
1936         }
1937     }
1938     // where
1939         private ResultInfo caseLabelResultInfo(Type seltype) {
1940             return new ResultInfo(KindSelector.VAL_TYP,
1941                                   !seltype.hasTag(ERROR) ? seltype
1942                                                          : Type.noType);
1943         }
1944         /** Add any variables defined in stats to the switch scope. */
1945         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
1946             for (;stats.nonEmpty(); stats = stats.tail) {
1947                 JCTree stat = stats.head;
1948                 if (stat.hasTag(VARDEF))
1949                     switchScope.enter(((JCVariableDecl) stat).sym);
1950             }
1951         }
1952     // where
1953     /** Return the selected enumeration constant symbol, or null. */
1954     private Symbol enumConstant(JCTree tree, Type enumType) {
1955         if (tree.hasTag(IDENT)) {
1956             JCIdent ident = (JCIdent)tree;
1957             Name name = ident.name;
1958             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
1959                 if (sym.kind == VAR) {
1960                     Symbol s = ident.sym = sym;
1961                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1962                     ident.type = s.type;
1963                     return ((s.flags_field & Flags.ENUM) == 0)
1964                         ? null : s;
1965                 }
1966             }
1967         }
1968         return null;
1969     }
1970 
1971     public void visitSynchronized(JCSynchronized tree) {
1972         boolean identityType = chk.checkIdentityType(tree.pos(), attribExpr(tree.lock, env));
1973         if (identityType && tree.lock.type != null && tree.lock.type.isValueBased()) {
1974             log.warning(tree.pos(), LintWarnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
1975         }
1976         attribStat(tree.body, env);
1977         result = null;
1978     }
1979 
1980     public void visitTry(JCTry tree) {
1981         // Create a new local environment with a local
1982         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1983         try {
1984             boolean isTryWithResource = tree.resources.nonEmpty();
1985             // Create a nested environment for attributing the try block if needed
1986             Env<AttrContext> tryEnv = isTryWithResource ?
1987                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1988                 localEnv;
1989             try {
1990                 // Attribute resource declarations
1991                 for (JCTree resource : tree.resources) {
1992                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
1993                         @Override
1994                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
1995                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
1996                         }
1997                     };
1998                     ResultInfo twrResult =
1999                         new ResultInfo(KindSelector.VAR,
2000                                        syms.autoCloseableType,
2001                                        twrContext);
2002                     if (resource.hasTag(VARDEF)) {
2003                         attribStat(resource, tryEnv);
2004                         twrResult.check(resource, resource.type);
2005 
2006                         //check that resource type cannot throw InterruptedException
2007                         checkAutoCloseable(localEnv, resource, true);
2008 
2009                         VarSymbol var = ((JCVariableDecl) resource).sym;
2010 
2011                         var.flags_field |= Flags.FINAL;
2012                         var.setData(ElementKind.RESOURCE_VARIABLE);
2013                     } else {
2014                         attribTree(resource, tryEnv, twrResult);
2015                     }
2016                 }
2017                 // Attribute body
2018                 attribStat(tree.body, tryEnv);
2019             } finally {
2020                 if (isTryWithResource)
2021                     tryEnv.info.scope.leave();
2022             }
2023 
2024             // Attribute catch clauses
2025             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
2026                 JCCatch c = l.head;
2027                 Env<AttrContext> catchEnv =
2028                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
2029                 try {
2030                     Type ctype = attribStat(c.param, catchEnv);
2031                     if (TreeInfo.isMultiCatch(c)) {
2032                         //multi-catch parameter is implicitly marked as final
2033                         c.param.sym.flags_field |= FINAL | UNION;
2034                     }
2035                     if (c.param.sym.kind == VAR) {
2036                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
2037                     }
2038                     chk.checkType(c.param.vartype.pos(),
2039                                   chk.checkClassType(c.param.vartype.pos(), ctype),
2040                                   syms.throwableType);
2041                     attribStat(c.body, catchEnv);
2042                 } finally {
2043                     catchEnv.info.scope.leave();
2044                 }
2045             }
2046 
2047             // Attribute finalizer
2048             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
2049             result = null;
2050         }
2051         finally {
2052             localEnv.info.scope.leave();
2053         }
2054     }
2055 
2056     void checkAutoCloseable(Env<AttrContext> env, JCTree tree, boolean useSite) {
2057         DiagnosticPosition pos = tree.pos();
2058         Type resource = tree.type;
2059         if (!resource.isErroneous() &&
2060             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
2061             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
2062             Symbol close = syms.noSymbol;
2063             Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
2064             try {
2065                 close = rs.resolveQualifiedMethod(pos,
2066                         env,
2067                         types.skipTypeVars(resource, false),
2068                         names.close,
2069                         List.nil(),
2070                         List.nil());
2071             }
2072             finally {
2073                 log.popDiagnosticHandler(discardHandler);
2074             }
2075             if (close.kind == MTH &&
2076                     (useSite || close.owner != syms.autoCloseableType.tsym) &&
2077                     ((MethodSymbol)close).binaryOverrides(syms.autoCloseableClose, resource.tsym, types) &&
2078                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes())) {
2079                 if (!useSite && close.owner == resource.tsym) {
2080                     log.warning(TreeInfo.diagnosticPositionFor(close, tree),
2081                         LintWarnings.TryResourceCanThrowInterruptedExc(resource));
2082                 } else {
2083                     log.warning(pos, LintWarnings.TryResourceThrowsInterruptedExc(resource));
2084                 }
2085             }
2086         }
2087     }
2088 
2089     public void visitConditional(JCConditional tree) {
2090         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2091         MatchBindings condBindings = matchBindings;
2092 
2093         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2094                 isBooleanOrNumeric(env, tree)) ?
2095                 PolyKind.STANDALONE : PolyKind.POLY;
2096 
2097         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2098             //this means we are returning a poly conditional from void-compatible lambda expression
2099             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2100             result = tree.type = types.createErrorType(resultInfo.pt);
2101             return;
2102         }
2103 
2104         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2105                 unknownExprInfo :
2106                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2107 
2108 
2109         // x ? y : z
2110         // include x's bindings when true in y
2111         // include x's bindings when false in z
2112 
2113         Type truetype;
2114         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2115         try {
2116             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2117         } finally {
2118             trueEnv.info.scope.leave();
2119         }
2120 
2121         MatchBindings trueBindings = matchBindings;
2122 
2123         Type falsetype;
2124         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2125         try {
2126             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2127         } finally {
2128             falseEnv.info.scope.leave();
2129         }
2130 
2131         MatchBindings falseBindings = matchBindings;
2132 
2133         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2134                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2135                          List.of(truetype, falsetype)) : pt();
2136         if (condtype.constValue() != null &&
2137                 truetype.constValue() != null &&
2138                 falsetype.constValue() != null &&
2139                 !owntype.hasTag(NONE)) {
2140             //constant folding
2141             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2142         }
2143         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2144         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2145     }
2146     //where
2147         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2148             switch (tree.getTag()) {
2149                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2150                               ((JCLiteral)tree).typetag == BOOLEAN ||
2151                               ((JCLiteral)tree).typetag == BOT;
2152                 case LAMBDA: case REFERENCE: return false;
2153                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2154                 case CONDEXPR:
2155                     JCConditional condTree = (JCConditional)tree;
2156                     return isBooleanOrNumeric(env, condTree.truepart) &&
2157                             isBooleanOrNumeric(env, condTree.falsepart);
2158                 case APPLY:
2159                     JCMethodInvocation speculativeMethodTree =
2160                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2161                                     tree, env, unknownExprInfo,
2162                                     argumentAttr.withLocalCacheContext());
2163                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2164                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2165                             env.enclClass.type :
2166                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2167                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2168                     return primitiveOrBoxed(owntype);
2169                 case NEWCLASS:
2170                     JCExpression className =
2171                             removeClassParams.translate(((JCNewClass)tree).clazz);
2172                     JCExpression speculativeNewClassTree =
2173                             (JCExpression)deferredAttr.attribSpeculative(
2174                                     className, env, unknownTypeInfo,
2175                                     argumentAttr.withLocalCacheContext());
2176                     return primitiveOrBoxed(speculativeNewClassTree.type);
2177                 default:
2178                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2179                             argumentAttr.withLocalCacheContext()).type;
2180                     return primitiveOrBoxed(speculativeType);
2181             }
2182         }
2183         //where
2184             boolean primitiveOrBoxed(Type t) {
2185                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2186             }
2187 
2188             TreeTranslator removeClassParams = new TreeTranslator() {
2189                 @Override
2190                 public void visitTypeApply(JCTypeApply tree) {
2191                     result = translate(tree.clazz);
2192                 }
2193             };
2194 
2195         CheckContext conditionalContext(CheckContext checkContext) {
2196             return new Check.NestedCheckContext(checkContext) {
2197                 //this will use enclosing check context to check compatibility of
2198                 //subexpression against target type; if we are in a method check context,
2199                 //depending on whether boxing is allowed, we could have incompatibilities
2200                 @Override
2201                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2202                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2203                 }
2204             };
2205         }
2206 
2207         /** Compute the type of a conditional expression, after
2208          *  checking that it exists.  See JLS 15.25. Does not take into
2209          *  account the special case where condition and both arms
2210          *  are constants.
2211          *
2212          *  @param pos      The source position to be used for error
2213          *                  diagnostics.
2214          *  @param thentype The type of the expression's then-part.
2215          *  @param elsetype The type of the expression's else-part.
2216          */
2217         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2218             if (condTypes.isEmpty()) {
2219                 return syms.objectType; //TODO: how to handle?
2220             }
2221             Type first = condTypes.head;
2222             // If same type, that is the result
2223             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2224                 return first.baseType();
2225 
2226             List<Type> unboxedTypes = condTypes.stream()
2227                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2228                                                .collect(List.collector());
2229 
2230             // Otherwise, if both arms can be converted to a numeric
2231             // type, return the least numeric type that fits both arms
2232             // (i.e. return larger of the two, or return int if one
2233             // arm is short, the other is char).
2234             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2235                 // If one arm has an integer subrange type (i.e., byte,
2236                 // short, or char), and the other is an integer constant
2237                 // that fits into the subrange, return the subrange type.
2238                 for (Type type : unboxedTypes) {
2239                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2240                         continue;
2241                     }
2242                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2243                         return type.baseType();
2244                 }
2245 
2246                 for (TypeTag tag : primitiveTags) {
2247                     Type candidate = syms.typeOfTag[tag.ordinal()];
2248                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2249                         return candidate;
2250                     }
2251                 }
2252             }
2253 
2254             // Those were all the cases that could result in a primitive
2255             condTypes = condTypes.stream()
2256                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
2257                                  .collect(List.collector());
2258 
2259             for (Type type : condTypes) {
2260                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2261                     return type.baseType();
2262             }
2263 
2264             Iterator<DiagnosticPosition> posIt = positions.iterator();
2265 
2266             condTypes = condTypes.stream()
2267                                  .map(t -> chk.checkNonVoid(posIt.next(), t))
2268                                  .collect(List.collector());
2269 
2270             // both are known to be reference types.  The result is
2271             // lub(thentype,elsetype). This cannot fail, as it will
2272             // always be possible to infer "Object" if nothing better.
2273             return types.lub(condTypes.stream()
2274                         .map(t -> t.baseType())
2275                         .filter(t -> !t.hasTag(BOT))
2276                         .collect(List.collector()));
2277         }
2278 
2279     static final TypeTag[] primitiveTags = new TypeTag[]{
2280         BYTE,
2281         CHAR,
2282         SHORT,
2283         INT,
2284         LONG,
2285         FLOAT,
2286         DOUBLE,
2287         BOOLEAN,
2288     };
2289 
2290     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2291         return bindingEnv(env, env.tree, bindings);
2292     }
2293 
2294     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2295         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2296         bindings.forEach(env1.info.scope::enter);
2297         return env1;
2298     }
2299 
2300     public void visitIf(JCIf tree) {
2301         attribExpr(tree.cond, env, syms.booleanType);
2302 
2303         // if (x) { y } [ else z ]
2304         // include x's bindings when true in y
2305         // include x's bindings when false in z
2306 
2307         MatchBindings condBindings = matchBindings;
2308         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2309 
2310         try {
2311             attribStat(tree.thenpart, thenEnv);
2312         } finally {
2313             thenEnv.info.scope.leave();
2314         }
2315 
2316         preFlow(tree.thenpart);
2317         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2318         boolean aliveAfterElse;
2319 
2320         if (tree.elsepart != null) {
2321             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2322             try {
2323                 attribStat(tree.elsepart, elseEnv);
2324             } finally {
2325                 elseEnv.info.scope.leave();
2326             }
2327             preFlow(tree.elsepart);
2328             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2329         } else {
2330             aliveAfterElse = true;
2331         }
2332 
2333         chk.checkEmptyIf(tree);
2334 
2335         List<BindingSymbol> afterIfBindings = List.nil();
2336 
2337         if (aliveAfterThen && !aliveAfterElse) {
2338             afterIfBindings = condBindings.bindingsWhenTrue;
2339         } else if (aliveAfterElse && !aliveAfterThen) {
2340             afterIfBindings = condBindings.bindingsWhenFalse;
2341         }
2342 
2343         addBindings2Scope(tree, afterIfBindings);
2344 
2345         result = null;
2346     }
2347 
2348         void preFlow(JCTree tree) {
2349             attrRecover.doRecovery();
2350             new PostAttrAnalyzer() {
2351                 @Override
2352                 public void scan(JCTree tree) {
2353                     if (tree == null ||
2354                             (tree.type != null &&
2355                             tree.type == Type.stuckType)) {
2356                         //don't touch stuck expressions!
2357                         return;
2358                     }
2359                     super.scan(tree);
2360                 }
2361 
2362                 @Override
2363                 public void visitClassDef(JCClassDecl that) {
2364                     if (that.sym != null) {
2365                         // Method preFlow shouldn't visit class definitions
2366                         // that have not been entered and attributed.
2367                         // See JDK-8254557 and JDK-8203277 for more details.
2368                         super.visitClassDef(that);
2369                     }
2370                 }
2371 
2372                 @Override
2373                 public void visitLambda(JCLambda that) {
2374                     if (that.type != null) {
2375                         // Method preFlow shouldn't visit lambda expressions
2376                         // that have not been entered and attributed.
2377                         // See JDK-8254557 and JDK-8203277 for more details.
2378                         super.visitLambda(that);
2379                     }
2380                 }
2381             }.scan(tree);
2382         }
2383 
2384     public void visitExec(JCExpressionStatement tree) {
2385         //a fresh environment is required for 292 inference to work properly ---
2386         //see Infer.instantiatePolymorphicSignatureInstance()
2387         Env<AttrContext> localEnv = env.dup(tree);
2388         attribExpr(tree.expr, localEnv);
2389         result = null;
2390     }
2391 
2392     public void visitBreak(JCBreak tree) {
2393         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2394         result = null;
2395     }
2396 
2397     public void visitYield(JCYield tree) {
2398         if (env.info.yieldResult != null) {
2399             attribTree(tree.value, env, env.info.yieldResult);
2400             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2401         } else {
2402             log.error(tree.pos(), tree.value.hasTag(PARENS)
2403                     ? Errors.NoSwitchExpressionQualify
2404                     : Errors.NoSwitchExpression);
2405             attribTree(tree.value, env, unknownExprInfo);
2406         }
2407         result = null;
2408     }
2409 
2410     public void visitContinue(JCContinue tree) {
2411         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2412         result = null;
2413     }
2414     //where
2415         /** Return the target of a break, continue or yield statement,
2416          *  if it exists, report an error if not.
2417          *  Note: The target of a labelled break or continue is the
2418          *  (non-labelled) statement tree referred to by the label,
2419          *  not the tree representing the labelled statement itself.
2420          *
2421          *  @param pos     The position to be used for error diagnostics
2422          *  @param tag     The tag of the jump statement. This is either
2423          *                 Tree.BREAK or Tree.CONTINUE.
2424          *  @param label   The label of the jump statement, or null if no
2425          *                 label is given.
2426          *  @param env     The environment current at the jump statement.
2427          */
2428         private JCTree findJumpTarget(DiagnosticPosition pos,
2429                                                    JCTree.Tag tag,
2430                                                    Name label,
2431                                                    Env<AttrContext> env) {
2432             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2433 
2434             if (jumpTarget.snd != null) {
2435                 log.error(pos, jumpTarget.snd);
2436             }
2437 
2438             return jumpTarget.fst;
2439         }
2440         /** Return the target of a break or continue statement, if it exists,
2441          *  report an error if not.
2442          *  Note: The target of a labelled break or continue is the
2443          *  (non-labelled) statement tree referred to by the label,
2444          *  not the tree representing the labelled statement itself.
2445          *
2446          *  @param tag     The tag of the jump statement. This is either
2447          *                 Tree.BREAK or Tree.CONTINUE.
2448          *  @param label   The label of the jump statement, or null if no
2449          *                 label is given.
2450          *  @param env     The environment current at the jump statement.
2451          */
2452         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2453                                                                        Name label,
2454                                                                        Env<AttrContext> env) {
2455             // Search environments outwards from the point of jump.
2456             Env<AttrContext> env1 = env;
2457             JCDiagnostic.Error pendingError = null;
2458             LOOP:
2459             while (env1 != null) {
2460                 switch (env1.tree.getTag()) {
2461                     case LABELLED:
2462                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2463                         if (label == labelled.label) {
2464                             // If jump is a continue, check that target is a loop.
2465                             if (tag == CONTINUE) {
2466                                 if (!labelled.body.hasTag(DOLOOP) &&
2467                                         !labelled.body.hasTag(WHILELOOP) &&
2468                                         !labelled.body.hasTag(FORLOOP) &&
2469                                         !labelled.body.hasTag(FOREACHLOOP)) {
2470                                     pendingError = Errors.NotLoopLabel(label);
2471                                 }
2472                                 // Found labelled statement target, now go inwards
2473                                 // to next non-labelled tree.
2474                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2475                             } else {
2476                                 return Pair.of(labelled, pendingError);
2477                             }
2478                         }
2479                         break;
2480                     case DOLOOP:
2481                     case WHILELOOP:
2482                     case FORLOOP:
2483                     case FOREACHLOOP:
2484                         if (label == null) return Pair.of(env1.tree, pendingError);
2485                         break;
2486                     case SWITCH:
2487                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2488                         break;
2489                     case SWITCH_EXPRESSION:
2490                         if (tag == YIELD) {
2491                             return Pair.of(env1.tree, null);
2492                         } else if (tag == BREAK) {
2493                             pendingError = Errors.BreakOutsideSwitchExpression;
2494                         } else {
2495                             pendingError = Errors.ContinueOutsideSwitchExpression;
2496                         }
2497                         break;
2498                     case LAMBDA:
2499                     case METHODDEF:
2500                     case CLASSDEF:
2501                         break LOOP;
2502                     default:
2503                 }
2504                 env1 = env1.next;
2505             }
2506             if (label != null)
2507                 return Pair.of(null, Errors.UndefLabel(label));
2508             else if (pendingError != null)
2509                 return Pair.of(null, pendingError);
2510             else if (tag == CONTINUE)
2511                 return Pair.of(null, Errors.ContOutsideLoop);
2512             else
2513                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2514         }
2515 
2516     public void visitReturn(JCReturn tree) {
2517         // Check that there is an enclosing method which is
2518         // nested within than the enclosing class.
2519         if (env.info.returnResult == null) {
2520             log.error(tree.pos(), Errors.RetOutsideMeth);
2521         } else if (env.info.yieldResult != null) {
2522             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2523             if (tree.expr != null) {
2524                 attribExpr(tree.expr, env, env.info.yieldResult.pt);
2525             }
2526         } else if (!env.info.isLambda &&
2527                 env.enclMethod != null &&
2528                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2529             log.error(env.enclMethod,
2530                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2531         } else {
2532             // Attribute return expression, if it exists, and check that
2533             // it conforms to result type of enclosing method.
2534             if (tree.expr != null) {
2535                 if (env.info.returnResult.pt.hasTag(VOID)) {
2536                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2537                               diags.fragment(Fragments.UnexpectedRetVal));
2538                 }
2539                 attribTree(tree.expr, env, env.info.returnResult);
2540             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2541                     !env.info.returnResult.pt.hasTag(NONE)) {
2542                 env.info.returnResult.checkContext.report(tree.pos(),
2543                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2544             }
2545         }
2546         result = null;
2547     }
2548 
2549     public void visitThrow(JCThrow tree) {
2550         Type owntype = attribExpr(tree.expr, env, Type.noType);
2551         chk.checkType(tree, owntype, syms.throwableType);
2552         result = null;
2553     }
2554 
2555     public void visitAssert(JCAssert tree) {
2556         attribExpr(tree.cond, env, syms.booleanType);
2557         if (tree.detail != null) {
2558             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2559         }
2560         result = null;
2561     }
2562 
2563      /** Visitor method for method invocations.
2564      *  NOTE: The method part of an application will have in its type field
2565      *        the return type of the method, not the method's type itself!
2566      */
2567     public void visitApply(JCMethodInvocation tree) {
2568         // The local environment of a method application is
2569         // a new environment nested in the current one.
2570         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2571 
2572         // The types of the actual method arguments.
2573         List<Type> argtypes;
2574 
2575         // The types of the actual method type arguments.
2576         List<Type> typeargtypes = null;
2577 
2578         Name methName = TreeInfo.name(tree.meth);
2579 
2580         boolean isConstructorCall =
2581             methName == names._this || methName == names._super;
2582 
2583         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2584         if (isConstructorCall) {
2585 
2586             // Attribute arguments, yielding list of argument types.
2587             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2588             argtypes = argtypesBuf.toList();
2589             typeargtypes = attribTypes(tree.typeargs, localEnv);
2590 
2591             // Done with this()/super() parameters.
2592             if (!env.info.earlyContext.onlyWarnings()) {
2593                 // End of constructor prologue (but only if no initialization warnings are needed)
2594                 env.info.earlyContext = EarlyConstructionContext.NONE;
2595             }
2596 
2597             // Variable `site' points to the class in which the called
2598             // constructor is defined.
2599             Type site = env.enclClass.sym.type;
2600             if (methName == names._super) {
2601                 if (site == syms.objectType) {
2602                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2603                     site = types.createErrorType(syms.objectType);
2604                 } else {
2605                     site = types.supertype(site);
2606                 }
2607             }
2608 
2609             if (site.hasTag(CLASS)) {
2610                 Type encl = site.getEnclosingType();
2611                 while (encl != null && encl.hasTag(TYPEVAR))
2612                     encl = encl.getUpperBound();
2613                 if (encl.hasTag(CLASS)) {
2614                     // we are calling a nested class
2615 
2616                     if (tree.meth.hasTag(SELECT)) {
2617                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2618 
2619                         // We are seeing a prefixed call, of the form
2620                         //     <expr>.super(...).
2621                         // Check that the prefix expression conforms
2622                         // to the outer instance type of the class.
2623                         chk.checkRefType(qualifier.pos(),
2624                                          attribExpr(qualifier, localEnv,
2625                                                     encl));
2626                     }
2627                 } else if (tree.meth.hasTag(SELECT)) {
2628                     log.error(tree.meth.pos(),
2629                               Errors.IllegalQualNotIcls(site.tsym));
2630                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2631                 }
2632 
2633                 if (tree.meth.hasTag(IDENT)) {
2634                     // non-qualified super(...) call; check whether explicit constructor
2635                     // invocation is well-formed. If the super class is an inner class,
2636                     // make sure that an appropriate implicit qualifier exists. If the super
2637                     // class is a local class, make sure that the current class is defined
2638                     // in the same context as the local class.
2639                     checkNewInnerClass(tree.meth.pos(), localEnv, site, true);
2640                 }
2641 
2642                 // if we're calling a java.lang.Enum constructor,
2643                 // prefix the implicit String and int parameters
2644                 if (site.tsym == syms.enumSym)
2645                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
2646 
2647                 // Resolve the called constructor under the assumption
2648                 // that we are referring to a superclass instance of the
2649                 // current instance (JLS ???).
2650                 boolean selectSuperPrev = localEnv.info.selectSuper;
2651                 localEnv.info.selectSuper = true;
2652                 localEnv.info.pendingResolutionPhase = null;
2653                 Symbol sym = rs.resolveConstructor(
2654                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
2655                 localEnv.info.selectSuper = selectSuperPrev;
2656 
2657                 // Set method symbol to resolved constructor...
2658                 TreeInfo.setSymbol(tree.meth, sym);
2659 
2660                 // ...and check that it is legal in the current context.
2661                 // (this will also set the tree's type)
2662                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2663                 checkId(tree.meth, site, sym, localEnv,
2664                         new ResultInfo(kind, mpt));
2665             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
2666                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2667             }
2668             // Otherwise, `site' is an error type and we do nothing
2669             result = tree.type = syms.voidType;
2670         } else {
2671             // Otherwise, we are seeing a regular method call.
2672             // Attribute the arguments, yielding list of argument types, ...
2673             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2674             argtypes = argtypesBuf.toList();
2675             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
2676 
2677             // ... and attribute the method using as a prototype a methodtype
2678             // whose formal argument types is exactly the list of actual
2679             // arguments (this will also set the method symbol).
2680             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2681             localEnv.info.pendingResolutionPhase = null;
2682             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
2683 
2684             // Compute the result type.
2685             Type restype = mtype.getReturnType();
2686             if (restype.hasTag(WILDCARD))
2687                 throw new AssertionError(mtype);
2688 
2689             Type qualifier = (tree.meth.hasTag(SELECT))
2690                     ? ((JCFieldAccess) tree.meth).selected.type
2691                     : env.enclClass.sym.type;
2692             Symbol msym = TreeInfo.symbol(tree.meth);
2693             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
2694 
2695             chk.checkRefTypes(tree.typeargs, typeargtypes);
2696 
2697             // Check that value of resulting type is admissible in the
2698             // current context.  Also, capture the return type
2699             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
2700             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
2701         }
2702         chk.checkRequiresIdentity(tree, env.info.lint);
2703         chk.validate(tree.typeargs, localEnv);
2704     }
2705     //where
2706         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
2707             if (msym != null &&
2708                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
2709                     methodName == names.getClass &&
2710                     argtypes.isEmpty()) {
2711                 // as a special case, x.getClass() has type Class<? extends |X|>
2712                 return new ClassType(restype.getEnclosingType(),
2713                         List.of(new WildcardType(types.erasure(qualifierType.baseType()),
2714                                 BoundKind.EXTENDS,
2715                                 syms.boundClass)),
2716                         restype.tsym,
2717                         restype.getMetadata());
2718             } else if (msym != null &&
2719                     msym.owner == syms.arrayClass &&
2720                     methodName == names.clone &&
2721                     types.isArray(qualifierType)) {
2722                 // as a special case, array.clone() has a result that is
2723                 // the same as static type of the array being cloned
2724                 return qualifierType;
2725             } else {
2726                 return restype;
2727             }
2728         }
2729 
2730         /** Obtain a method type with given argument types.
2731          */
2732         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
2733             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
2734             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
2735         }
2736 
2737     public void visitNewClass(final JCNewClass tree) {
2738         Type owntype = types.createErrorType(tree.type);
2739 
2740         // The local environment of a class creation is
2741         // a new environment nested in the current one.
2742         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2743 
2744         // The anonymous inner class definition of the new expression,
2745         // if one is defined by it.
2746         JCClassDecl cdef = tree.def;
2747 
2748         // If enclosing class is given, attribute it, and
2749         // complete class name to be fully qualified
2750         JCExpression clazz = tree.clazz; // Class field following new
2751         JCExpression clazzid;            // Identifier in class field
2752         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
2753         annoclazzid = null;
2754 
2755         if (clazz.hasTag(TYPEAPPLY)) {
2756             clazzid = ((JCTypeApply) clazz).clazz;
2757             if (clazzid.hasTag(ANNOTATED_TYPE)) {
2758                 annoclazzid = (JCAnnotatedType) clazzid;
2759                 clazzid = annoclazzid.underlyingType;
2760             }
2761         } else {
2762             if (clazz.hasTag(ANNOTATED_TYPE)) {
2763                 annoclazzid = (JCAnnotatedType) clazz;
2764                 clazzid = annoclazzid.underlyingType;
2765             } else {
2766                 clazzid = clazz;
2767             }
2768         }
2769 
2770         JCExpression clazzid1 = clazzid; // The same in fully qualified form
2771 
2772         if (tree.encl != null) {
2773             // We are seeing a qualified new, of the form
2774             //    <expr>.new C <...> (...) ...
2775             // In this case, we let clazz stand for the name of the
2776             // allocated class C prefixed with the type of the qualifier
2777             // expression, so that we can
2778             // resolve it with standard techniques later. I.e., if
2779             // <expr> has type T, then <expr>.new C <...> (...)
2780             // yields a clazz T.C.
2781             Type encltype = chk.checkRefType(tree.encl.pos(),
2782                                              attribExpr(tree.encl, env));
2783             // TODO 308: in <expr>.new C, do we also want to add the type annotations
2784             // from expr to the combined type, or not? Yes, do this.
2785             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
2786                                                  ((JCIdent) clazzid).name);
2787 
2788             clazzid1.endpos = clazzid.getEndPosition();
2789             if (clazz.hasTag(ANNOTATED_TYPE)) {
2790                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
2791                 List<JCAnnotation> annos = annoType.annotations;
2792 
2793                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
2794                     clazzid1 = make.at(tree.pos).
2795                         TypeApply(clazzid1,
2796                                   ((JCTypeApply) clazz).arguments);
2797                 }
2798 
2799                 clazzid1 = make.at(tree.pos).
2800                     AnnotatedType(annos, clazzid1);
2801             } else if (clazz.hasTag(TYPEAPPLY)) {
2802                 clazzid1 = make.at(tree.pos).
2803                     TypeApply(clazzid1,
2804                               ((JCTypeApply) clazz).arguments);
2805             }
2806 
2807             clazz = clazzid1;
2808         }
2809 
2810         // Attribute clazz expression and store
2811         // symbol + type back into the attributed tree.
2812         Type clazztype = TreeInfo.isEnumInit(env.tree) ?
2813             attribIdentAsEnumType(env, (JCIdent)clazz) :
2814             attribType(clazz, env);
2815 
2816         clazztype = chk.checkDiamond(tree, clazztype);
2817         chk.validate(clazz, localEnv);
2818         if (tree.encl != null) {
2819             // We have to work in this case to store
2820             // symbol + type back into the attributed tree.
2821             tree.clazz.type = clazztype;
2822             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
2823             clazzid.type = ((JCIdent) clazzid).sym.type;
2824             if (annoclazzid != null) {
2825                 annoclazzid.type = clazzid.type;
2826             }
2827             if (!clazztype.isErroneous()) {
2828                 if (cdef != null && clazztype.tsym.isInterface()) {
2829                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
2830                 } else if (clazztype.tsym.isStatic()) {
2831                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
2832                 }
2833             }
2834         } else {
2835             // Check for the existence of an apropos outer instance
2836             checkNewInnerClass(tree.pos(), env, clazztype, false);
2837         }
2838 
2839         checkBreakTree(tree.clazz, localEnv);
2840 
2841         // Attribute constructor arguments.
2842         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2843         final KindSelector pkind =
2844             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2845         List<Type> argtypes = argtypesBuf.toList();
2846         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
2847 
2848         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
2849             // Enums may not be instantiated except implicitly
2850             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
2851                 (!env.tree.hasTag(VARDEF) ||
2852                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
2853                  ((JCVariableDecl) env.tree).init != tree))
2854                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
2855 
2856             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
2857                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
2858             boolean skipNonDiamondPath = false;
2859             // Check that class is not abstract
2860             if (cdef == null && !tree.classDeclRemoved() && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
2861                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
2862                 log.error(tree.pos(),
2863                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
2864                 skipNonDiamondPath = true;
2865             } else if (cdef != null && clazztype.tsym.isInterface()) {
2866                 // Check that no constructor arguments are given to
2867                 // anonymous classes implementing an interface
2868                 if (!argtypes.isEmpty())
2869                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
2870 
2871                 if (!typeargtypes.isEmpty())
2872                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
2873 
2874                 // Error recovery: pretend no arguments were supplied.
2875                 argtypes = List.nil();
2876                 typeargtypes = List.nil();
2877                 skipNonDiamondPath = true;
2878             }
2879             if (TreeInfo.isDiamond(tree)) {
2880                 ClassType site = new ClassType(clazztype.getEnclosingType(),
2881                             clazztype.tsym.type.getTypeArguments(),
2882                                                clazztype.tsym,
2883                                                clazztype.getMetadata());
2884 
2885                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
2886                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
2887                 diamondEnv.info.pendingResolutionPhase = null;
2888 
2889                 //if the type of the instance creation expression is a class type
2890                 //apply method resolution inference (JLS 15.12.2.7). The return type
2891                 //of the resolved constructor will be a partially instantiated type
2892                 Symbol constructor = rs.resolveDiamond(tree.pos(),
2893                             diamondEnv,
2894                             site,
2895                             argtypes,
2896                             typeargtypes);
2897                 tree.constructor = constructor.baseSymbol();
2898 
2899                 final TypeSymbol csym = clazztype.tsym;
2900                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
2901                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
2902                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
2903                 constructorType = checkId(tree, site,
2904                         constructor,
2905                         diamondEnv,
2906                         diamondResult);
2907 
2908                 tree.clazz.type = types.createErrorType(clazztype);
2909                 if (!constructorType.isErroneous()) {
2910                     tree.clazz.type = clazz.type = constructorType.getReturnType();
2911                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
2912                 }
2913                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
2914             }
2915 
2916             // Resolve the called constructor under the assumption
2917             // that we are referring to a superclass instance of the
2918             // current instance (JLS ???).
2919             else if (!skipNonDiamondPath) {
2920                 //the following code alters some of the fields in the current
2921                 //AttrContext - hence, the current context must be dup'ed in
2922                 //order to avoid downstream failures
2923                 Env<AttrContext> rsEnv = localEnv.dup(tree);
2924                 rsEnv.info.selectSuper = cdef != null;
2925                 rsEnv.info.pendingResolutionPhase = null;
2926                 tree.constructor = rs.resolveConstructor(
2927                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
2928                 if (cdef == null) { //do not check twice!
2929                     tree.constructorType = checkId(tree,
2930                             clazztype,
2931                             tree.constructor,
2932                             rsEnv,
2933                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
2934                     if (rsEnv.info.lastResolveVarargs())
2935                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
2936                 }
2937             }
2938 
2939             chk.checkRequiresIdentity(tree, env.info.lint);
2940 
2941             if (cdef != null) {
2942                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
2943                 return;
2944             }
2945 
2946             if (tree.constructor != null && tree.constructor.kind == MTH)
2947                 owntype = clazztype;
2948         }
2949         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2950         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2951         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
2952             //we need to wait for inference to finish and then replace inference vars in the constructor type
2953             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
2954                     instantiatedContext -> {
2955                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2956                     });
2957         }
2958         chk.validate(tree.typeargs, localEnv);
2959     }
2960 
2961         // where
2962         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
2963                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
2964                                                    List<Type> argtypes, List<Type> typeargtypes,
2965                                                    KindSelector pkind) {
2966             // We are seeing an anonymous class instance creation.
2967             // In this case, the class instance creation
2968             // expression
2969             //
2970             //    E.new <typeargs1>C<typargs2>(args) { ... }
2971             //
2972             // is represented internally as
2973             //
2974             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
2975             //
2976             // This expression is then *transformed* as follows:
2977             //
2978             // (1) add an extends or implements clause
2979             // (2) add a constructor.
2980             //
2981             // For instance, if C is a class, and ET is the type of E,
2982             // the expression
2983             //
2984             //    E.new <typeargs1>C<typargs2>(args) { ... }
2985             //
2986             // is translated to (where X is a fresh name and typarams is the
2987             // parameter list of the super constructor):
2988             //
2989             //   new <typeargs1>X(<*nullchk*>E, args) where
2990             //     X extends C<typargs2> {
2991             //       <typarams> X(ET e, args) {
2992             //         e.<typeargs1>super(args)
2993             //       }
2994             //       ...
2995             //     }
2996             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2997             Type enclType = clazztype.getEnclosingType();
2998             if (enclType != null &&
2999                     enclType.hasTag(CLASS) &&
3000                     !chk.checkDenotable((ClassType)enclType)) {
3001                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
3002             }
3003             final boolean isDiamond = TreeInfo.isDiamond(tree);
3004             if (isDiamond
3005                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
3006                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
3007                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
3008                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
3009                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
3010                         instantiatedContext -> {
3011                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
3012                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
3013                             ResultInfo prevResult = this.resultInfo;
3014                             try {
3015                                 this.resultInfo = resultInfoForClassDefinition;
3016                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
3017                                         dupLocalEnv, argtypes, typeargtypes, pkind);
3018                             } finally {
3019                                 this.resultInfo = prevResult;
3020                             }
3021                         });
3022             } else {
3023                 if (isDiamond && clazztype.hasTag(CLASS)) {
3024                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
3025                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
3026                         // One or more types inferred in the previous steps is non-denotable.
3027                         Fragment fragment = Diamond(clazztype.tsym);
3028                         log.error(tree.clazz.pos(),
3029                                 Errors.CantApplyDiamond1(
3030                                         fragment,
3031                                         invalidDiamondArgs.size() > 1 ?
3032                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
3033                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
3034                     }
3035                     // For <>(){}, inferred types must also be accessible.
3036                     for (Type t : clazztype.getTypeArguments()) {
3037                         rs.checkAccessibleType(env, t);
3038                     }
3039                 }
3040 
3041                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
3042                 // false for isInterface call even when the original type is an interface.
3043                 boolean implementing = clazztype.tsym.isInterface() ||
3044                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
3045                         clazztype.getOriginalType().tsym.isInterface();
3046 
3047                 if (implementing) {
3048                     cdef.implementing = List.of(clazz);
3049                 } else {
3050                     cdef.extending = clazz;
3051                 }
3052 
3053                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3054                     rs.isSerializable(clazztype)) {
3055                     localEnv.info.isSerializable = true;
3056                 }
3057 
3058                 attribStat(cdef, localEnv);
3059 
3060                 List<Type> finalargtypes;
3061                 // If an outer instance is given,
3062                 // prefix it to the constructor arguments
3063                 // and delete it from the new expression
3064                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
3065                     finalargtypes = argtypes.prepend(tree.encl.type);
3066                 } else {
3067                     finalargtypes = argtypes;
3068                 }
3069 
3070                 // Reassign clazztype and recompute constructor. As this necessarily involves
3071                 // another attribution pass for deferred types in the case of <>, replicate
3072                 // them. Original arguments have right decorations already.
3073                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3074                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3075                 }
3076 
3077                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3078                                                     : cdef.sym.type;
3079                 Symbol sym = tree.constructor = rs.resolveConstructor(
3080                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3081                 Assert.check(!sym.kind.isResolutionError());
3082                 tree.constructor = sym;
3083                 tree.constructorType = checkId(tree,
3084                         clazztype,
3085                         tree.constructor,
3086                         localEnv,
3087                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3088             }
3089             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3090                                 clazztype : types.createErrorType(tree.type);
3091             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3092             chk.validate(tree.typeargs, localEnv);
3093         }
3094 
3095         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3096             return new Check.NestedCheckContext(checkContext) {
3097                 @Override
3098                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3099                     enclosingContext.report(clazz.clazz,
3100                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3101                 }
3102             };
3103         }
3104 
3105         void checkNewInnerClass(DiagnosticPosition pos, Env<AttrContext> env, Type type, boolean isSuper) {
3106             boolean isLocal = type.tsym.owner.kind == VAR || type.tsym.owner.kind == MTH;
3107             if ((type.tsym.flags() & (INTERFACE | ENUM | RECORD)) != 0 ||
3108                     (!isLocal && !type.tsym.isInner()) ||
3109                     (isSuper && env.enclClass.sym.isAnonymous())) {
3110                 // nothing to check
3111                 return;
3112             }
3113             Symbol res = isLocal ?
3114                     rs.findLocalClassOwner(env, type.tsym) :
3115                     rs.findSelfContaining(pos, env, type.getEnclosingType().tsym, isSuper);
3116             if (res.exists()) {
3117                 rs.accessBase(res, pos, env.enclClass.sym.type, names._this, true);
3118             } else {
3119                 log.error(pos, Errors.EnclClassRequired(type.tsym));
3120             }
3121         }
3122 
3123     /** Make an attributed null check tree.
3124      */
3125     public JCExpression makeNullCheck(JCExpression arg) {
3126         // optimization: new Outer() can never be null; skip null check
3127         if (arg.getTag() == NEWCLASS)
3128             return arg;
3129         // optimization: X.this is never null; skip null check
3130         Name name = TreeInfo.name(arg);
3131         if (name == names._this || name == names._super) return arg;
3132 
3133         JCTree.Tag optag = NULLCHK;
3134         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3135         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3136         tree.type = arg.type;
3137         return tree;
3138     }
3139 
3140     public void visitNewArray(JCNewArray tree) {
3141         Type owntype = types.createErrorType(tree.type);
3142         Env<AttrContext> localEnv = env.dup(tree);
3143         Type elemtype;
3144         if (tree.elemtype != null) {
3145             elemtype = attribType(tree.elemtype, localEnv);
3146             chk.validate(tree.elemtype, localEnv);
3147             owntype = elemtype;
3148             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3149                 attribExpr(l.head, localEnv, syms.intType);
3150                 owntype = new ArrayType(owntype, syms.arrayClass);
3151             }
3152         } else {
3153             // we are seeing an untyped aggregate { ... }
3154             // this is allowed only if the prototype is an array
3155             if (pt().hasTag(ARRAY)) {
3156                 elemtype = types.elemtype(pt());
3157             } else {
3158                 if (!pt().hasTag(ERROR) &&
3159                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3160                     log.error(tree.pos(),
3161                               Errors.IllegalInitializerForType(pt()));
3162                 }
3163                 elemtype = types.createErrorType(pt());
3164             }
3165         }
3166         if (tree.elems != null) {
3167             attribExprs(tree.elems, localEnv, elemtype);
3168             owntype = new ArrayType(elemtype, syms.arrayClass);
3169         }
3170         if (!types.isReifiable(elemtype))
3171             log.error(tree.pos(), Errors.GenericArrayCreation);
3172         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3173     }
3174 
3175     /*
3176      * A lambda expression can only be attributed when a target-type is available.
3177      * In addition, if the target-type is that of a functional interface whose
3178      * descriptor contains inference variables in argument position the lambda expression
3179      * is 'stuck' (see DeferredAttr).
3180      */
3181     @Override
3182     public void visitLambda(final JCLambda that) {
3183         boolean wrongContext = false;
3184         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3185             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3186                 //lambda only allowed in assignment or method invocation/cast context
3187                 log.error(that.pos(), Errors.UnexpectedLambda);
3188             }
3189             resultInfo = recoveryInfo;
3190             wrongContext = true;
3191         }
3192         //create an environment for attribution of the lambda expression
3193         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3194         boolean needsRecovery =
3195                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3196         try {
3197             if (needsRecovery && rs.isSerializable(pt())) {
3198                 localEnv.info.isSerializable = true;
3199                 localEnv.info.isSerializableLambda = true;
3200             }
3201             List<Type> explicitParamTypes = null;
3202             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3203                 //attribute lambda parameters
3204                 attribStats(that.params, localEnv);
3205                 explicitParamTypes = TreeInfo.types(that.params);
3206             }
3207 
3208             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3209             Type currentTarget = targetInfo.target;
3210             Type lambdaType = targetInfo.descriptor;
3211 
3212             if (currentTarget.isErroneous()) {
3213                 result = that.type = currentTarget;
3214                 return;
3215             }
3216 
3217             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3218 
3219             if (lambdaType.hasTag(FORALL)) {
3220                 //lambda expression target desc cannot be a generic method
3221                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3222                                                                     kindName(currentTarget.tsym),
3223                                                                     currentTarget.tsym);
3224                 resultInfo.checkContext.report(that, diags.fragment(msg));
3225                 result = that.type = types.createErrorType(pt());
3226                 return;
3227             }
3228 
3229             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3230                 //add param type info in the AST
3231                 List<Type> actuals = lambdaType.getParameterTypes();
3232                 List<JCVariableDecl> params = that.params;
3233 
3234                 boolean arityMismatch = false;
3235 
3236                 while (params.nonEmpty()) {
3237                     if (actuals.isEmpty()) {
3238                         //not enough actuals to perform lambda parameter inference
3239                         arityMismatch = true;
3240                     }
3241                     //reset previously set info
3242                     Type argType = arityMismatch ?
3243                             syms.errType :
3244                             actuals.head;
3245                     if (params.head.type == null &&
3246                         params.head.isImplicitlyTyped()) { //error recovery
3247                         params.head.type = argType;
3248                         setupImplicitlyTypedVariable(params.head, argType);
3249                     }
3250                     params.head.sym = null;
3251                     actuals = actuals.isEmpty() ?
3252                             actuals :
3253                             actuals.tail;
3254                     params = params.tail;
3255                 }
3256 
3257                 //attribute lambda parameters
3258                 attribStats(that.params, localEnv);
3259 
3260                 if (arityMismatch) {
3261                     resultInfo.checkContext.report(that, diags.fragment(Fragments.WrongNumberArgsInLambda(currentTarget.tsym)));
3262                         result = that.type = types.createErrorType(currentTarget);
3263                         return;
3264                 }
3265             }
3266 
3267             //from this point on, no recovery is needed; if we are in assignment context
3268             //we will be able to attribute the whole lambda body, regardless of errors;
3269             //if we are in a 'check' method context, and the lambda is not compatible
3270             //with the target-type, it will be recovered anyway in Attr.checkId
3271             needsRecovery = false;
3272 
3273             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3274                     lambdaBodyResult(that, lambdaType, resultInfo);
3275 
3276             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3277                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3278             } else {
3279                 JCBlock body = (JCBlock)that.body;
3280 
3281                 checkBreakTree(body, localEnv);
3282                 attribStats(body.stats, localEnv);
3283             }
3284 
3285             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3286 
3287             boolean isSpeculativeRound =
3288                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3289 
3290             preFlow(that);
3291             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3292 
3293             that.type = currentTarget; //avoids recovery at this stage
3294             checkLambdaCompatible(that, lambdaType, currentTarget.tsym, resultInfo.checkContext);
3295 
3296             if (!isSpeculativeRound) {
3297                 //add thrown types as bounds to the thrown types free variables if needed:
3298                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3299                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3300                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3301                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3302                     }
3303                 }
3304 
3305                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3306             }
3307             result = wrongContext ? that.type = types.createErrorType(pt())
3308                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3309         } catch (Types.FunctionDescriptorLookupError ex) {
3310             JCDiagnostic cause = ex.getDiagnostic();
3311             resultInfo.checkContext.report(that, cause);
3312             result = that.type = types.createErrorType(pt());
3313             return;
3314         } catch (CompletionFailure cf) {
3315             chk.completionError(that.pos(), cf);
3316         } catch (Throwable t) {
3317             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3318             //as that would likely cause the same exception again.
3319             needsRecovery = false;
3320             throw t;
3321         } finally {
3322             localEnv.info.scope.leave();
3323             if (needsRecovery) {
3324                 Type prevResult = result;
3325                 try {
3326                     attribTree(that, env, recoveryInfo);
3327                 } finally {
3328                     if (result == Type.recoveryType) {
3329                         result = prevResult;
3330                     }
3331                 }
3332             }
3333         }
3334     }
3335     //where
3336         class TargetInfo {
3337             Type target;
3338             Type descriptor;
3339 
3340             public TargetInfo(Type target, Type descriptor) {
3341                 this.target = target;
3342                 this.descriptor = descriptor;
3343             }
3344         }
3345 
3346         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3347             Type lambdaType;
3348             Type currentTarget = resultInfo.pt;
3349             if (resultInfo.pt != Type.recoveryType) {
3350                 /* We need to adjust the target. If the target is an
3351                  * intersection type, for example: SAM & I1 & I2 ...
3352                  * the target will be updated to SAM
3353                  */
3354                 currentTarget = targetChecker.visit(currentTarget, that);
3355                 if (!currentTarget.isIntersection()) {
3356                     if (explicitParamTypes != null) {
3357                         currentTarget = infer.instantiateFunctionalInterface(that,
3358                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3359                     }
3360                     currentTarget = types.removeWildcards(currentTarget);
3361                     lambdaType = types.findDescriptorType(currentTarget);
3362                 } else {
3363                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3364                     ListBuffer<Type> components = new ListBuffer<>();
3365                     for (Type bound : ict.getExplicitComponents()) {
3366                         if (explicitParamTypes != null) {
3367                             try {
3368                                 bound = infer.instantiateFunctionalInterface(that,
3369                                         bound, explicitParamTypes, resultInfo.checkContext);
3370                             } catch (FunctionDescriptorLookupError t) {
3371                                 // do nothing
3372                             }
3373                         }
3374                         if (bound.tsym != syms.objectType.tsym && (!bound.isInterface() || (bound.tsym.flags() & ANNOTATION) != 0)) {
3375                             // bound must be j.l.Object or an interface, but not an annotation
3376                             reportIntersectionError(that, "not.an.intf.component", bound);
3377                         }
3378                         bound = types.removeWildcards(bound);
3379                         components.add(bound);
3380                     }
3381                     currentTarget = types.makeIntersectionType(components.toList());
3382                     currentTarget.tsym.flags_field |= INTERFACE;
3383                     lambdaType = types.findDescriptorType(currentTarget);
3384                 }
3385 
3386             } else {
3387                 currentTarget = Type.recoveryType;
3388                 lambdaType = fallbackDescriptorType(that);
3389             }
3390             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3391                 //lambda expression target desc cannot be a generic method
3392                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3393                                                                     kindName(currentTarget.tsym),
3394                                                                     currentTarget.tsym);
3395                 resultInfo.checkContext.report(that, diags.fragment(msg));
3396                 currentTarget = types.createErrorType(pt());
3397             }
3398             return new TargetInfo(currentTarget, lambdaType);
3399         }
3400 
3401         private void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) {
3402              resultInfo.checkContext.report(pos,
3403                  diags.fragment(Fragments.BadIntersectionTargetForFunctionalExpr(diags.fragment(key, args))));
3404         }
3405 
3406         void preFlow(JCLambda tree) {
3407             attrRecover.doRecovery();
3408             new PostAttrAnalyzer() {
3409                 @Override
3410                 public void scan(JCTree tree) {
3411                     if (tree == null ||
3412                             (tree.type != null &&
3413                             tree.type == Type.stuckType)) {
3414                         //don't touch stuck expressions!
3415                         return;
3416                     }
3417                     super.scan(tree);
3418                 }
3419 
3420                 @Override
3421                 public void visitClassDef(JCClassDecl that) {
3422                     // or class declaration trees!
3423                 }
3424 
3425                 public void visitLambda(JCLambda that) {
3426                     // or lambda expressions!
3427                 }
3428             }.scan(tree.body);
3429         }
3430 
3431         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3432 
3433             @Override
3434             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3435                 return t.isIntersection() ?
3436                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3437             }
3438 
3439             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3440                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3441                 return ict;
3442             }
3443 
3444             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3445                 ListBuffer<Type> targs = new ListBuffer<>();
3446                 ListBuffer<Type> supertypes = new ListBuffer<>();
3447                 for (Type i : ict.interfaces_field) {
3448                     if (i.isParameterized()) {
3449                         targs.appendList(i.tsym.type.allparams());
3450                     }
3451                     supertypes.append(i.tsym.type);
3452                 }
3453                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3454                 notionalIntf.allparams_field = targs.toList();
3455                 notionalIntf.tsym.flags_field |= INTERFACE;
3456                 return notionalIntf.tsym;
3457             }
3458         };
3459 
3460         private Type fallbackDescriptorType(JCExpression tree) {
3461             switch (tree.getTag()) {
3462                 case LAMBDA:
3463                     JCLambda lambda = (JCLambda)tree;
3464                     List<Type> argtypes = List.nil();
3465                     for (JCVariableDecl param : lambda.params) {
3466                         argtypes = !param.isImplicitlyTyped() && param.vartype.type != null ?
3467                                 argtypes.append(param.vartype.type) :
3468                                 argtypes.append(syms.errType);
3469                     }
3470                     return new MethodType(argtypes, Type.recoveryType,
3471                             List.of(syms.throwableType), syms.methodClass);
3472                 case REFERENCE:
3473                     return new MethodType(List.nil(), Type.recoveryType,
3474                             List.of(syms.throwableType), syms.methodClass);
3475                 default:
3476                     Assert.error("Cannot get here!");
3477             }
3478             return null;
3479         }
3480 
3481         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3482                 final InferenceContext inferenceContext, final Type... ts) {
3483             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3484         }
3485 
3486         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3487                 final InferenceContext inferenceContext, final List<Type> ts) {
3488             if (inferenceContext.free(ts)) {
3489                 inferenceContext.addFreeTypeListener(ts,
3490                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3491             } else {
3492                 for (Type t : ts) {
3493                     rs.checkAccessibleType(env, t);
3494                 }
3495             }
3496         }
3497 
3498         /**
3499          * Lambda/method reference have a special check context that ensures
3500          * that i.e. a lambda return type is compatible with the expected
3501          * type according to both the inherited context and the assignment
3502          * context.
3503          */
3504         class FunctionalReturnContext extends Check.NestedCheckContext {
3505 
3506             FunctionalReturnContext(CheckContext enclosingContext) {
3507                 super(enclosingContext);
3508             }
3509 
3510             @Override
3511             public boolean compatible(Type found, Type req, Warner warn) {
3512                 //return type must be compatible in both current context and assignment context
3513                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3514             }
3515 
3516             @Override
3517             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3518                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3519             }
3520         }
3521 
3522         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3523 
3524             JCExpression expr;
3525             boolean expStmtExpected;
3526 
3527             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3528                 super(enclosingContext);
3529                 this.expr = expr;
3530             }
3531 
3532             @Override
3533             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3534                 if (expStmtExpected) {
3535                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3536                 } else {
3537                     super.report(pos, details);
3538                 }
3539             }
3540 
3541             @Override
3542             public boolean compatible(Type found, Type req, Warner warn) {
3543                 //a void return is compatible with an expression statement lambda
3544                 if (req.hasTag(VOID)) {
3545                     expStmtExpected = true;
3546                     return TreeInfo.isExpressionStatement(expr);
3547                 } else {
3548                     return super.compatible(found, req, warn);
3549                 }
3550             }
3551         }
3552 
3553         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3554             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3555                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3556                     new FunctionalReturnContext(resultInfo.checkContext);
3557 
3558             return descriptor.getReturnType() == Type.recoveryType ?
3559                     recoveryInfo :
3560                     new ResultInfo(KindSelector.VAL,
3561                             descriptor.getReturnType(), funcContext);
3562         }
3563 
3564         /**
3565         * Lambda compatibility. Check that given return types, thrown types, parameter types
3566         * are compatible with the expected functional interface descriptor. This means that:
3567         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3568         * types must be compatible with the return type of the expected descriptor.
3569         */
3570         void checkLambdaCompatible(JCLambda tree, Type descriptor, TypeSymbol target, CheckContext checkContext) {
3571             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3572 
3573             //return values have already been checked - but if lambda has no return
3574             //values, we must ensure that void/value compatibility is correct;
3575             //this amounts at checking that, if a lambda body can complete normally,
3576             //the descriptor's return type must be void
3577             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3578                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3579                 Fragment msg =
3580                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3581                 checkContext.report(tree,
3582                                     diags.fragment(msg));
3583             }
3584 
3585             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3586             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3587                 checkContext.report(tree, diags.fragment(argTypes.size() != tree.params.size()
3588                         ? Fragments.WrongNumberArgsInLambda(target)
3589                         : Fragments.IncompatibleArgTypesInLambda(argTypes, TreeInfo.types(tree.params))));
3590             }
3591         }
3592 
3593         /* This method returns an environment to be used to attribute a lambda
3594          * expression.
3595          *
3596          * The owner of this environment is a method symbol. If the current owner
3597          * is not a method (e.g. if the lambda occurs in a field initializer), then
3598          * a synthetic method symbol owner is created.
3599          */
3600         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3601             Env<AttrContext> lambdaEnv;
3602             Symbol owner = env.info.scope.owner;
3603             if (owner.kind == VAR && owner.owner.kind == TYP) {
3604                 // If the lambda is nested in a field initializer, we need to create a fake init method.
3605                 // Uniqueness of this symbol is not important (as e.g. annotations will be added on the
3606                 // init symbol's owner).
3607                 ClassSymbol enclClass = owner.enclClass();
3608                 Name initName = owner.isStatic() ? names.clinit : names.init;
3609                 MethodSymbol initSym = new MethodSymbol(BLOCK | (owner.isStatic() ? STATIC : 0) | SYNTHETIC | PRIVATE,
3610                         initName, initBlockType, enclClass);
3611                 initSym.params = List.nil();
3612                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(initSym)));
3613             } else {
3614                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3615             }
3616             lambdaEnv.info.yieldResult = null;
3617             lambdaEnv.info.isLambda = true;
3618             lambdaEnv.info.earlyContext = lambdaEnv.info.earlyContext.nested(false);
3619             return lambdaEnv;
3620         }
3621 
3622     @Override
3623     public void visitReference(final JCMemberReference that) {
3624         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3625             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3626                 //method reference only allowed in assignment or method invocation/cast context
3627                 log.error(that.pos(), Errors.UnexpectedMref);
3628             }
3629             result = that.type = types.createErrorType(pt());
3630             return;
3631         }
3632         final Env<AttrContext> localEnv = env.dup(that);
3633         try {
3634             //attribute member reference qualifier - if this is a constructor
3635             //reference, the expected kind must be a type
3636             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3637 
3638             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3639                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3640                 if (!exprType.isErroneous() &&
3641                     exprType.isRaw() &&
3642                     that.typeargs != null) {
3643                     log.error(that.expr.pos(),
3644                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3645                                                  Fragments.MrefInferAndExplicitParams));
3646                     exprType = types.createErrorType(exprType);
3647                 }
3648             }
3649 
3650             if (exprType.isErroneous()) {
3651                 //if the qualifier expression contains problems,
3652                 //give up attribution of method reference
3653                 result = that.type = exprType;
3654                 return;
3655             }
3656 
3657             if (TreeInfo.isStaticSelector(that.expr, names)) {
3658                 //if the qualifier is a type, validate it; raw warning check is
3659                 //omitted as we don't know at this stage as to whether this is a
3660                 //raw selector (because of inference)
3661                 chk.validate(that.expr, env, false);
3662             } else {
3663                 Symbol lhsSym = TreeInfo.symbol(that.expr);
3664                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
3665             }
3666             //attrib type-arguments
3667             List<Type> typeargtypes = List.nil();
3668             if (that.typeargs != null) {
3669                 typeargtypes = attribTypes(that.typeargs, localEnv);
3670             }
3671 
3672             boolean isTargetSerializable =
3673                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3674                     rs.isSerializable(pt());
3675             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
3676             Type currentTarget = targetInfo.target;
3677             Type desc = targetInfo.descriptor;
3678 
3679             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
3680             List<Type> argtypes = desc.getParameterTypes();
3681             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
3682 
3683             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
3684                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
3685             }
3686 
3687             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
3688             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
3689             try {
3690                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
3691                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
3692                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
3693             } finally {
3694                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
3695             }
3696 
3697             Symbol refSym = refResult.fst;
3698             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
3699 
3700             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
3701              *  JDK-8075541
3702              */
3703             if (refSym.kind != MTH) {
3704                 boolean targetError;
3705                 switch (refSym.kind) {
3706                     case ABSENT_MTH:
3707                         targetError = false;
3708                         break;
3709                     case WRONG_MTH:
3710                     case WRONG_MTHS:
3711                     case AMBIGUOUS:
3712                     case HIDDEN:
3713                     case STATICERR:
3714                         targetError = true;
3715                         break;
3716                     default:
3717                         Assert.error("unexpected result kind " + refSym.kind);
3718                         targetError = false;
3719                 }
3720 
3721                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
3722                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
3723                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
3724 
3725                 JCDiagnostic diag = diags.create(log.currentSource(), that,
3726                         targetError ?
3727                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
3728                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
3729 
3730                 if (targetError && currentTarget == Type.recoveryType) {
3731                     //a target error doesn't make sense during recovery stage
3732                     //as we don't know what actual parameter types are
3733                     result = that.type = currentTarget;
3734                     return;
3735                 } else {
3736                     if (targetError) {
3737                         resultInfo.checkContext.report(that, diag);
3738                     } else {
3739                         log.report(diag);
3740                     }
3741                     result = that.type = types.createErrorType(currentTarget);
3742                     return;
3743                 }
3744             }
3745 
3746             that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
3747             that.kind = lookupHelper.referenceKind(that.sym);
3748             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
3749 
3750             if (desc.getReturnType() == Type.recoveryType) {
3751                 // stop here
3752                 result = that.type = currentTarget;
3753                 return;
3754             }
3755 
3756             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3757                 checkNewInnerClass(that.pos(), env, exprType, false);
3758             }
3759 
3760             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3761 
3762                 if (that.getMode() == ReferenceMode.INVOKE &&
3763                         TreeInfo.isStaticSelector(that.expr, names) &&
3764                         that.kind.isUnbound() &&
3765                         lookupHelper.site.isRaw()) {
3766                     chk.checkRaw(that.expr, localEnv);
3767                 }
3768 
3769                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
3770                         exprType.getTypeArguments().nonEmpty()) {
3771                     //static ref with class type-args
3772                     log.error(that.expr.pos(),
3773                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3774                                                  Fragments.StaticMrefWithTargs));
3775                     result = that.type = types.createErrorType(currentTarget);
3776                     return;
3777                 }
3778 
3779                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
3780                     // Check that super-qualified symbols are not abstract (JLS)
3781                     rs.checkNonAbstract(that.pos(), that.sym);
3782                 }
3783 
3784                 if (isTargetSerializable) {
3785                     chk.checkAccessFromSerializableElement(that, true);
3786                 }
3787             }
3788 
3789             ResultInfo checkInfo =
3790                     resultInfo.dup(newMethodTemplate(
3791                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
3792                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
3793                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3794 
3795             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
3796 
3797             if (that.kind.isUnbound() &&
3798                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
3799                 //re-generate inference constraints for unbound receiver
3800                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
3801                     //cannot happen as this has already been checked - we just need
3802                     //to regenerate the inference constraints, as that has been lost
3803                     //as a result of the call to inferenceContext.save()
3804                     Assert.error("Can't get here");
3805                 }
3806             }
3807 
3808             if (!refType.isErroneous()) {
3809                 refType = types.createMethodTypeWithReturn(refType,
3810                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
3811             }
3812 
3813             //go ahead with standard method reference compatibility check - note that param check
3814             //is a no-op (as this has been taken care during method applicability)
3815             boolean isSpeculativeRound =
3816                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3817 
3818             that.type = currentTarget; //avoids recovery at this stage
3819             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
3820             if (!isSpeculativeRound) {
3821                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
3822             }
3823             chk.checkRequiresIdentity(that, localEnv.info.lint);
3824             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3825         } catch (Types.FunctionDescriptorLookupError ex) {
3826             JCDiagnostic cause = ex.getDiagnostic();
3827             resultInfo.checkContext.report(that, cause);
3828             result = that.type = types.createErrorType(pt());
3829             return;
3830         }
3831     }
3832     //where
3833         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
3834             //if this is a constructor reference, the expected kind must be a type
3835             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
3836                                   KindSelector.VAL_TYP : KindSelector.TYP,
3837                                   Type.noType);
3838         }
3839 
3840 
3841     @SuppressWarnings("fallthrough")
3842     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
3843         InferenceContext inferenceContext = checkContext.inferenceContext();
3844         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
3845 
3846         Type resType;
3847         switch (tree.getMode()) {
3848             case NEW:
3849                 if (!tree.expr.type.isRaw()) {
3850                     resType = tree.expr.type;
3851                     break;
3852                 }
3853             default:
3854                 resType = refType.getReturnType();
3855         }
3856 
3857         Type incompatibleReturnType = resType;
3858 
3859         if (returnType.hasTag(VOID)) {
3860             incompatibleReturnType = null;
3861         }
3862 
3863         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
3864             Type capturedResType = captureMRefReturnType ? types.capture(resType) : resType;
3865             if (resType.isErroneous() ||
3866                     new FunctionalReturnContext(checkContext).compatible(capturedResType, returnType,
3867                             checkContext.checkWarner(tree, capturedResType, returnType))) {
3868                 incompatibleReturnType = null;
3869             }
3870         }
3871 
3872         if (incompatibleReturnType != null) {
3873             Fragment msg =
3874                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
3875             checkContext.report(tree, diags.fragment(msg));
3876         } else {
3877             if (inferenceContext.free(refType)) {
3878                 // we need to wait for inference to finish and then replace inference vars in the referent type
3879                 inferenceContext.addFreeTypeListener(List.of(refType),
3880                         instantiatedContext -> {
3881                             tree.referentType = instantiatedContext.asInstType(refType);
3882                         });
3883             } else {
3884                 tree.referentType = refType;
3885             }
3886         }
3887 
3888         if (!speculativeAttr) {
3889             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
3890                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
3891             }
3892         }
3893     }
3894 
3895     boolean checkExConstraints(
3896             List<Type> thrownByFuncExpr,
3897             List<Type> thrownAtFuncType,
3898             InferenceContext inferenceContext) {
3899         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
3900          *  are not proper types
3901          */
3902         List<Type> nonProperList = thrownAtFuncType.stream()
3903                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
3904         List<Type> properList = thrownAtFuncType.diff(nonProperList);
3905 
3906         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
3907          *  in the throws clause of the invocation type of the method reference's compile-time
3908          *  declaration
3909          */
3910         List<Type> checkedList = thrownByFuncExpr.stream()
3911                 .filter(e -> chk.isChecked(e)).collect(List.collector());
3912 
3913         /** If n = 0 (the function type's throws clause consists only of proper types), then
3914          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
3915          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
3916          *  reduces to true
3917          */
3918         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
3919         for (Type checked : checkedList) {
3920             boolean isSubtype = false;
3921             for (Type proper : properList) {
3922                 if (types.isSubtype(checked, proper)) {
3923                     isSubtype = true;
3924                     break;
3925                 }
3926             }
3927             if (!isSubtype) {
3928                 uncaughtByProperTypes.add(checked);
3929             }
3930         }
3931 
3932         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
3933             return false;
3934         }
3935 
3936         /** If n > 0, the constraint reduces to a set of subtyping constraints:
3937          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
3938          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
3939          */
3940         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
3941         uncaughtByProperTypes.forEach(checkedEx -> {
3942             nonProperAsUndet.forEach(nonProper -> {
3943                 types.isSubtype(checkedEx, nonProper);
3944             });
3945         });
3946 
3947         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
3948          */
3949         nonProperAsUndet.stream()
3950                 .filter(t -> t.hasTag(UNDETVAR))
3951                 .forEach(t -> ((UndetVar)t).setThrow());
3952         return true;
3953     }
3954 
3955     /**
3956      * Set functional type info on the underlying AST. Note: as the target descriptor
3957      * might contain inference variables, we might need to register an hook in the
3958      * current inference context.
3959      */
3960     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
3961             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
3962         if (checkContext.inferenceContext().free(descriptorType)) {
3963             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
3964                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
3965                     inferenceContext.asInstType(primaryTarget), checkContext));
3966         } else {
3967             fExpr.owner = env.info.scope.owner;
3968             if (pt.hasTag(CLASS)) {
3969                 fExpr.target = primaryTarget;
3970             }
3971             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3972                     pt != Type.recoveryType) {
3973                 //check that functional interface class is well-formed
3974                 try {
3975                     /* Types.makeFunctionalInterfaceClass() may throw an exception
3976                      * when it's executed post-inference. See the listener code
3977                      * above.
3978                      */
3979                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
3980                             names.empty, fExpr.target, ABSTRACT);
3981                     if (csym != null) {
3982                         chk.checkImplementations(env.tree, csym, csym);
3983                         try {
3984                             //perform an additional functional interface check on the synthetic class,
3985                             //as there may be spurious errors for raw targets - because of existing issues
3986                             //with membership and inheritance (see JDK-8074570).
3987                             csym.flags_field |= INTERFACE;
3988                             types.findDescriptorType(csym.type);
3989                         } catch (FunctionDescriptorLookupError err) {
3990                             resultInfo.checkContext.report(fExpr,
3991                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
3992                         }
3993                     }
3994                 } catch (Types.FunctionDescriptorLookupError ex) {
3995                     JCDiagnostic cause = ex.getDiagnostic();
3996                     resultInfo.checkContext.report(env.tree, cause);
3997                 }
3998             }
3999         }
4000     }
4001 
4002     public void visitParens(JCParens tree) {
4003         Type owntype = attribTree(tree.expr, env, resultInfo);
4004         result = check(tree, owntype, pkind(), resultInfo);
4005         Symbol sym = TreeInfo.symbol(tree);
4006         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
4007             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
4008     }
4009 
4010     public void visitAssign(JCAssign tree) {
4011         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
4012         Type capturedType = capture(owntype);
4013         attribExpr(tree.rhs, env, owntype);
4014         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
4015     }
4016 
4017     public void visitAssignop(JCAssignOp tree) {
4018         // Attribute arguments.
4019         Type owntype = attribTree(tree.lhs, env, varAssignmentOpInfo);
4020         Type operand = attribExpr(tree.rhs, env);
4021         // Find operator.
4022         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
4023         if (operator != operators.noOpSymbol &&
4024                 !owntype.isErroneous() &&
4025                 !operand.isErroneous()) {
4026             chk.checkDivZero(tree.rhs.pos(), operator, operand);
4027             chk.checkCastable(tree.rhs.pos(),
4028                               operator.type.getReturnType(),
4029                               owntype);
4030             switch (tree.getTag()) {
4031             case SL_ASG, SR_ASG, USR_ASG -> { }     // we only use (at most) the lower 6 bits, so any integral type is OK
4032             default -> chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
4033             }
4034             chk.checkOutOfRangeShift(tree.rhs.pos(), operator, operand);
4035         }
4036         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4037     }
4038 
4039     public void visitUnary(JCUnary tree) {
4040         // Attribute arguments.
4041         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
4042             ? attribTree(tree.arg, env, varAssignmentOpInfo)
4043             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
4044 
4045         // Find operator.
4046         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
4047         Type owntype = types.createErrorType(tree.type);
4048         if (operator != operators.noOpSymbol &&
4049                 !argtype.isErroneous()) {
4050             owntype = (tree.getTag().isIncOrDecUnaryOp())
4051                 ? tree.arg.type
4052                 : operator.type.getReturnType();
4053             int opc = operator.opcode;
4054 
4055             // If the argument is constant, fold it.
4056             if (argtype.constValue() != null) {
4057                 Type ctype = cfolder.fold1(opc, argtype);
4058                 if (ctype != null) {
4059                     owntype = cfolder.coerce(ctype, owntype);
4060                 }
4061             }
4062         }
4063         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4064         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4065     }
4066 
4067     public void visitBinary(JCBinary tree) {
4068         // Attribute arguments.
4069         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4070         // x && y
4071         // include x's bindings when true in y
4072 
4073         // x || y
4074         // include x's bindings when false in y
4075 
4076         MatchBindings lhsBindings = matchBindings;
4077         List<BindingSymbol> propagatedBindings;
4078         switch (tree.getTag()) {
4079             case AND:
4080                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4081                 break;
4082             case OR:
4083                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4084                 break;
4085             default:
4086                 propagatedBindings = List.nil();
4087                 break;
4088         }
4089         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4090         Type right;
4091         try {
4092             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4093         } finally {
4094             rhsEnv.info.scope.leave();
4095         }
4096 
4097         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4098 
4099         // Find operator.
4100         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4101         Type owntype = types.createErrorType(tree.type);
4102         if (operator != operators.noOpSymbol &&
4103                 !left.isErroneous() &&
4104                 !right.isErroneous()) {
4105             owntype = operator.type.getReturnType();
4106             int opc = operator.opcode;
4107             // If both arguments are constants, fold them.
4108             if (left.constValue() != null && right.constValue() != null) {
4109                 Type ctype = cfolder.fold2(opc, left, right);
4110                 if (ctype != null) {
4111                     owntype = cfolder.coerce(ctype, owntype);
4112                 }
4113             }
4114 
4115             // Check that argument types of a reference ==, != are
4116             // castable to each other, (JLS 15.21).  Note: unboxing
4117             // comparisons will not have an acmp* opc at this point.
4118             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4119                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4120                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4121                 }
4122             }
4123 
4124             chk.checkDivZero(tree.rhs.pos(), operator, right);
4125             chk.checkOutOfRangeShift(tree.rhs.pos(), operator, right);
4126         }
4127         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4128     }
4129 
4130     public void visitTypeCast(final JCTypeCast tree) {
4131         Type clazztype = attribType(tree.clazz, env);
4132         chk.validate(tree.clazz, env, false);
4133         chk.checkRequiresIdentity(tree, env.info.lint);
4134         //a fresh environment is required for 292 inference to work properly ---
4135         //see Infer.instantiatePolymorphicSignatureInstance()
4136         Env<AttrContext> localEnv = env.dup(tree);
4137         //should we propagate the target type?
4138         final ResultInfo castInfo;
4139         JCExpression expr = TreeInfo.skipParens(tree.expr);
4140         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4141         if (isPoly) {
4142             //expression is a poly - we need to propagate target type info
4143             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4144                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4145                 @Override
4146                 public boolean compatible(Type found, Type req, Warner warn) {
4147                     return types.isCastable(found, req, warn);
4148                 }
4149             });
4150         } else {
4151             //standalone cast - target-type info is not propagated
4152             castInfo = unknownExprInfo;
4153         }
4154         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4155         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4156         if (exprtype.constValue() != null)
4157             owntype = cfolder.coerce(exprtype, owntype);
4158         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4159         if (!isPoly)
4160             chk.checkRedundantCast(localEnv, tree);
4161     }
4162 
4163     public void visitTypeTest(JCInstanceOf tree) {
4164         Type exprtype = attribExpr(tree.expr, env);
4165         if (exprtype.isPrimitive()) {
4166             preview.checkSourceLevel(tree.expr.pos(), Feature.PRIMITIVE_PATTERNS);
4167         } else {
4168             exprtype = chk.checkNullOrRefType(
4169                     tree.expr.pos(), exprtype);
4170         }
4171         Type clazztype;
4172         JCTree typeTree;
4173         if (tree.pattern.getTag() == BINDINGPATTERN ||
4174             tree.pattern.getTag() == RECORDPATTERN) {
4175             attribExpr(tree.pattern, env, exprtype);
4176             clazztype = tree.pattern.type;
4177             if (types.isSubtype(exprtype, clazztype) &&
4178                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4179                 tree.pattern.getTag() != RECORDPATTERN) {
4180                 if (!allowUnconditionalPatternsInstanceOf) {
4181                     log.error(tree.pos(), Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.error(this.sourceName));
4182                 }
4183             }
4184             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4185         } else {
4186             clazztype = attribType(tree.pattern, env);
4187             typeTree = tree.pattern;
4188             chk.validate(typeTree, env, false);
4189         }
4190         if (clazztype.isPrimitive()) {
4191             preview.checkSourceLevel(tree.pattern.pos(), Feature.PRIMITIVE_PATTERNS);
4192         } else {
4193             if (!clazztype.hasTag(TYPEVAR)) {
4194                 clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4195             }
4196             if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4197                 boolean valid = false;
4198                 if (allowReifiableTypesInInstanceof) {
4199                     valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4200                 } else {
4201                     log.error(tree.pos(), Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4202                     allowReifiableTypesInInstanceof = true;
4203                 }
4204                 if (!valid) {
4205                     clazztype = types.createErrorType(clazztype);
4206                 }
4207             }
4208         }
4209         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4210         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4211     }
4212 
4213     private boolean checkCastablePattern(DiagnosticPosition pos,
4214                                          Type exprType,
4215                                          Type pattType) {
4216         Warner warner = new Warner();
4217         // if any type is erroneous, the problem is reported elsewhere
4218         if (exprType.isErroneous() || pattType.isErroneous()) {
4219             return false;
4220         }
4221         if (!types.isCastable(exprType, pattType, warner)) {
4222             chk.basicHandler.report(pos,
4223                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4224             return false;
4225         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4226                 (!exprType.isPrimitive() || !pattType.isPrimitive() || !types.isSameType(exprType, pattType))) {
4227             preview.checkSourceLevel(pos, Feature.PRIMITIVE_PATTERNS);
4228             return true;
4229         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4230             log.error(pos,
4231                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4232             return false;
4233         } else {
4234             return true;
4235         }
4236     }
4237 
4238     @Override
4239     public void visitAnyPattern(JCAnyPattern tree) {
4240         result = tree.type = resultInfo.pt;
4241     }
4242 
4243     public void visitBindingPattern(JCBindingPattern tree) {
4244         Type type;
4245         if (!tree.var.isImplicitlyTyped()) {
4246             type = attribType(tree.var.vartype, env);
4247         } else {
4248             type = resultInfo.pt;
4249         }
4250         BindingSymbol v = new BindingSymbol(tree.var.mods.flags | tree.var.declKind.additionalSymbolFlags,
4251                                             tree.var.name, type, env.info.scope.owner);
4252         v.pos = tree.pos;
4253         tree.var.sym = v;
4254         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4255             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4256         }
4257         if (tree.var.isImplicitlyTyped()) {
4258             setupImplicitlyTypedVariable(tree.var, type == Type.noType ? syms.errType
4259                                                       : type);
4260         }
4261         chk.validate(tree.var.vartype, env, true);
4262         annotate.annotateLater(tree.var.mods.annotations, env, v);
4263         if (!tree.var.isImplicitlyTyped()) {
4264             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v);
4265         }
4266         annotate.flush();
4267         typeAnnotations.organizeTypeAnnotationsSignaturesForLocalVarType(env, tree.var);
4268         result = tree.type = tree.var.type = v.type;
4269         if (v.isUnnamedVariable()) {
4270             matchBindings = MatchBindingsComputer.EMPTY;
4271         } else {
4272             matchBindings = new MatchBindings(List.of(v), List.nil());
4273         }
4274         chk.checkRequiresIdentity(tree, env.info.lint);
4275     }
4276 
4277     @Override
4278     public void visitRecordPattern(JCRecordPattern tree) {
4279         Type site;
4280 
4281         if (tree.deconstructor.hasTag(VARTYPE)) {
4282             log.error(tree.pos(), Errors.DeconstructionPatternVarNotAllowed);
4283             tree.record = syms.errSymbol;
4284             site = tree.type = types.createErrorType(tree.record.type);
4285         } else {
4286             Type type = attribType(tree.deconstructor, env);
4287             if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4288                 Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4289                 if (inferred == null) {
4290                     log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4291                 } else {
4292                     type = inferred;
4293                 }
4294             }
4295             tree.type = tree.deconstructor.type = type;
4296             site = types.capture(tree.type);
4297             chk.validate(tree.deconstructor, env, true);
4298         }
4299 
4300         List<Type> expectedRecordTypes;
4301         if (site.tsym instanceof ClassSymbol clazz && clazz.isRecord()) {
4302             ClassSymbol record = (ClassSymbol) site.tsym;
4303             expectedRecordTypes = record.getRecordComponents()
4304                                         .stream()
4305                                         .map(rc -> types.memberType(site, rc))
4306                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4307                                         .collect(List.collector());
4308             tree.record = record;
4309         } else {
4310             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4311             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4312                                 .limit(tree.nested.size())
4313                                 .collect(List.collector());
4314             tree.record = syms.errSymbol;
4315         }
4316         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4317         List<Type> recordTypes = expectedRecordTypes;
4318         List<JCPattern> nestedPatterns = tree.nested;
4319         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4320         try {
4321             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4322                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4323                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4324                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4325                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4326                 nestedPatterns = nestedPatterns.tail;
4327                 recordTypes = recordTypes.tail;
4328             }
4329             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4330                 while (nestedPatterns.nonEmpty()) {
4331                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4332                     nestedPatterns = nestedPatterns.tail;
4333                 }
4334                 List<Type> nestedTypes =
4335                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4336                 log.error(tree.pos(),
4337                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4338                                                                  nestedTypes));
4339             }
4340         } finally {
4341             localEnv.info.scope.leave();
4342         }
4343         result = tree.type;
4344         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4345     }
4346 
4347     public void visitIndexed(JCArrayAccess tree) {
4348         Type owntype = types.createErrorType(tree.type);
4349         Type atype = attribExpr(tree.indexed, env);
4350         attribExpr(tree.index, env, syms.intType);
4351         if (types.isArray(atype))
4352             owntype = types.elemtype(atype);
4353         else if (!atype.hasTag(ERROR))
4354             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4355         if (!pkind().contains(KindSelector.VAL))
4356             owntype = capture(owntype);
4357         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4358     }
4359 
4360     public void visitIdent(JCIdent tree) {
4361         Symbol sym;
4362 
4363         // Find symbol
4364         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4365             // If we are looking for a method, the prototype `pt' will be a
4366             // method type with the type of the call's arguments as parameters.
4367             env.info.pendingResolutionPhase = null;
4368             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4369         } else if (tree.sym != null && tree.sym.kind != VAR) {
4370             sym = tree.sym;
4371         } else {
4372             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4373         }
4374         tree.sym = sym;
4375 
4376         // Also find the environment current for the class where
4377         // sym is defined (`symEnv').
4378         Env<AttrContext> symEnv = env;
4379         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4380             sym.kind.matches(KindSelector.VAL_MTH) &&
4381             sym.owner.kind == TYP &&
4382             tree.name != names._this && tree.name != names._super) {
4383 
4384             // Find environment in which identifier is defined.
4385             while (symEnv.outer != null &&
4386                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4387                 symEnv = symEnv.outer;
4388             }
4389         }
4390 
4391         // If symbol is a variable, ...
4392         if (sym.kind == VAR) {
4393             VarSymbol v = (VarSymbol)sym;
4394 
4395             // ..., evaluate its initializer, if it has one, and check for
4396             // illegal forward reference.
4397             checkInit(tree, env, v, false);
4398 
4399             // If we are expecting a variable (as opposed to a value), check
4400             // that the variable is assignable in the current environment.
4401             if (KindSelector.ASG.subset(pkind()))
4402                 checkAssignable(tree.pos(), v, null, env);
4403         }
4404 
4405         Env<AttrContext> env1 = env;
4406         if (sym.kind != ERR && sym.kind != TYP &&
4407             sym.owner != null && sym.owner != env1.enclClass.sym) {
4408             // If the found symbol is inaccessible, then it is
4409             // accessed through an enclosing instance.  Locate this
4410             // enclosing instance:
4411             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4412                 env1 = env1.outer;
4413         }
4414 
4415         if (env.info.isSerializable) {
4416             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4417         }
4418 
4419         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4420     }
4421 
4422     public void visitSelect(JCFieldAccess tree) {
4423         // Determine the expected kind of the qualifier expression.
4424         KindSelector skind = KindSelector.NIL;
4425         if (tree.name == names._this || tree.name == names._super ||
4426                 tree.name == names._class)
4427         {
4428             skind = KindSelector.TYP;
4429         } else {
4430             if (pkind().contains(KindSelector.PCK))
4431                 skind = KindSelector.of(skind, KindSelector.PCK);
4432             if (pkind().contains(KindSelector.TYP))
4433                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4434             if (pkind().contains(KindSelector.VAL_MTH))
4435                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4436         }
4437 
4438         // Attribute the qualifier expression, and determine its symbol (if any).
4439         Type site;
4440         EarlyConstructionContext earlyConstructionPrev = env.info.earlyContext;
4441         JCTree earlyFieldQualifier = earlyFieldQualifier(tree);
4442         try {
4443             if (earlyFieldQualifier != null) {
4444                 // if we're seeing a likely field access, and qualifier is this/super,
4445                 // pretend we're not in early construction context. This allows Resolve
4446                 // to skip premature checks against this/super
4447                 env.info.earlyContext = EarlyConstructionContext.NONE;
4448             }
4449             site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
4450         } finally {
4451             env.info.earlyContext = earlyConstructionPrev;
4452         }
4453         Assert.check(site == tree.selected.type);
4454         if (!pkind().contains(KindSelector.TYP_PCK))
4455             site = capture(site); // Capture field access
4456 
4457         // don't allow T.class T[].class, etc
4458         if (skind == KindSelector.TYP) {
4459             Type elt = site;
4460             while (elt.hasTag(ARRAY))
4461                 elt = ((ArrayType)elt).elemtype;
4462             if (elt.hasTag(TYPEVAR)) {
4463                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4464                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4465                 tree.sym = tree.type.tsym;
4466                 return ;
4467             }
4468         }
4469 
4470         // If qualifier symbol is a type or `super', assert `selectSuper'
4471         // for the selection. This is relevant for determining whether
4472         // protected symbols are accessible.
4473         Symbol sitesym = TreeInfo.symbol(tree.selected);
4474         boolean selectSuperPrev = env.info.selectSuper;
4475         env.info.selectSuper =
4476             sitesym != null &&
4477             sitesym.name == names._super;
4478 
4479         // Determine the symbol represented by the selection.
4480         env.info.pendingResolutionPhase = null;
4481         Symbol sym;
4482         sym = selectSym(tree, sitesym, site, env, resultInfo, earlyFieldQualifier);
4483         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4484             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4485             sym = syms.errSymbol;
4486         }
4487         if (sym.exists() && !isType(sym) &&
4488                 tree.name != names._this && tree.name != names._super &&
4489                 pkind().contains(KindSelector.TYP_PCK)) {
4490             site = capture(site);
4491             sym = selectSym(tree, sitesym, site, env, resultInfo, earlyFieldQualifier);
4492         }
4493         boolean varArgs = env.info.lastResolveVarargs();
4494         tree.sym = sym;
4495 
4496         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4497             site = types.skipTypeVars(site, true);
4498         }
4499 
4500         // If that symbol is a variable, ...
4501         if (sym.kind == VAR) {
4502             VarSymbol v = (VarSymbol)sym;
4503 
4504             // ..., evaluate its initializer, if it has one, and check for
4505             // illegal forward reference.
4506             checkInit(tree, env, v, true);
4507 
4508             // If we are expecting a variable (as opposed to a value), check
4509             // that the variable is assignable in the current environment.
4510             if (KindSelector.ASG.subset(pkind()))
4511                 checkAssignable(tree.pos(), v, tree.selected, env);
4512         }
4513 
4514         if (sitesym != null &&
4515                 sitesym.kind == VAR &&
4516                 ((VarSymbol)sitesym).isResourceVariable() &&
4517                 sym.kind == MTH &&
4518                 sym.name.equals(names.close) &&
4519                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true)) {
4520             log.warning(tree, LintWarnings.TryExplicitCloseCall);
4521         }
4522 
4523         // Disallow selecting a type from an expression
4524         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4525             tree.type = check(tree.selected, pt(),
4526                               sitesym == null ?
4527                                       KindSelector.VAL : sitesym.kind.toSelector(),
4528                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4529         }
4530 
4531         if (isType(sitesym)) {
4532             if (sym.name != names._this && sym.name != names._super) {
4533                 // Check if type-qualified fields or methods are static (JLS)
4534                 if ((sym.flags() & STATIC) == 0 &&
4535                     sym.name != names._super &&
4536                     (sym.kind == VAR || sym.kind == MTH)) {
4537                     rs.accessBase(rs.new StaticError(sym),
4538                               tree.pos(), site, sym.name, true);
4539                 }
4540             }
4541         } else if (sym.kind != ERR &&
4542                    (sym.flags() & STATIC) != 0 &&
4543                    sym.name != names._class) {
4544             // If the qualified item is not a type and the selected item is static, report
4545             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4546             if (!sym.owner.isAnonymous()) {
4547                 log.warning(tree, LintWarnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4548             } else {
4549                 log.warning(tree, LintWarnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4550             }
4551         }
4552 
4553         // If we are selecting an instance member via a `super', ...
4554         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4555 
4556             // Check that super-qualified symbols are not abstract (JLS)
4557             rs.checkNonAbstract(tree.pos(), sym);
4558 
4559             if (site.isRaw()) {
4560                 // Determine argument types for site.
4561                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
4562                 if (site1 != null) site = site1;
4563             }
4564         }
4565 
4566         if (env.info.isSerializable) {
4567             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4568         }
4569 
4570         env.info.selectSuper = selectSuperPrev;
4571         result = checkId(tree, site, sym, env, resultInfo);
4572     }
4573 
4574     private JCTree earlyFieldQualifier(JCFieldAccess tree) {
4575         boolean methodSelect = resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL);
4576         if (!methodSelect &&
4577                 (TreeInfo.isThisOrSelectorDotThis(tree.selected) ||
4578                 TreeInfo.isSuperOrSelectorDotSuper(tree.selected))) {
4579             return tree.selected;
4580         }
4581         return null;
4582     }
4583 
4584     //where
4585         /** Determine symbol referenced by a Select expression,
4586          *
4587          *  @param tree   The select tree.
4588          *  @param site   The type of the selected expression,
4589          *  @param env    The current environment.
4590          *  @param resultInfo The current result.
4591          */
4592         private Symbol selectSym(JCFieldAccess tree,
4593                                  Symbol location,
4594                                  Type site,
4595                                  Env<AttrContext> env,
4596                                  ResultInfo resultInfo,
4597                                  JCTree earlyFieldQualifier) {
4598             DiagnosticPosition pos = tree.pos();
4599             Name name = tree.name;
4600             switch (site.getTag()) {
4601             case PACKAGE:
4602                 return rs.accessBase(
4603                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4604                     pos, location, site, name, true);
4605             case ARRAY:
4606             case CLASS:
4607                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4608                     return rs.resolveQualifiedMethod(
4609                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4610                 } else if (name == names._this || name == names._super) {
4611                     Symbol sym = rs.resolveSelf(pos, env, site.tsym, tree);
4612                     return rs.accessBase(sym, pos, env.enclClass.sym.type, name, true);
4613                 } else if (name == names._class) {
4614                     // In this case, we have already made sure in
4615                     // visitSelect that qualifier expression is a type.
4616                     return syms.getClassField(site, types);
4617                 } else {
4618                     // We are seeing a plain identifier as selector.
4619                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind, earlyFieldQualifier);
4620                         sym = rs.accessBase(sym, pos, location, site, name, true);
4621                     return sym;
4622                 }
4623             case WILDCARD:
4624                 throw new AssertionError(tree);
4625             case TYPEVAR:
4626                 // Normally, site.getUpperBound() shouldn't be null.
4627                 // It should only happen during memberEnter/attribBase
4628                 // when determining the supertype which *must* be
4629                 // done before attributing the type variables.  In
4630                 // other words, we are seeing this illegal program:
4631                 // class B<T> extends A<T.foo> {}
4632                 Symbol sym = (site.getUpperBound() != null)
4633                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo, earlyFieldQualifier)
4634                     : null;
4635                 if (sym == null) {
4636                     log.error(pos, Errors.TypeVarCantBeDeref);
4637                     return syms.errSymbol;
4638                 } else {
4639                     // JLS 4.9 specifies the members are derived by inheritance.
4640                     // We skip inducing a whole class by filtering members that
4641                     // can never be inherited:
4642                     Symbol sym2;
4643                     if (sym.isPrivate()) {
4644                         // Private members
4645                         sym2 = rs.new AccessError(env, site, sym);
4646                     } else if (sym.owner.isInterface() && sym.kind == MTH && (sym.flags() & STATIC) != 0) {
4647                         // Interface static methods
4648                         sym2 = rs.new SymbolNotFoundError(ABSENT_MTH);
4649                     } else {
4650                         sym2 = sym;
4651                     }
4652                     rs.accessBase(sym2, pos, location, site, name, true);
4653                     return sym;
4654                 }
4655             case ERROR:
4656                 // preserve identifier names through errors
4657                 return types.createErrorType(name, site.tsym, site).tsym;
4658             default:
4659                 // The qualifier expression is of a primitive type -- only
4660                 // .class is allowed for these.
4661                 if (name == names._class) {
4662                     // In this case, we have already made sure in Select that
4663                     // qualifier expression is a type.
4664                     return syms.getClassField(site, types);
4665                 } else {
4666                     log.error(pos, Errors.CantDeref(site));
4667                     return syms.errSymbol;
4668                 }
4669             }
4670         }
4671 
4672         /** Determine type of identifier or select expression and check that
4673          *  (1) the referenced symbol is not deprecated
4674          *  (2) the symbol's type is safe (@see checkSafe)
4675          *  (3) if symbol is a variable, check that its type and kind are
4676          *      compatible with the prototype and protokind.
4677          *  (4) if symbol is an instance field of a raw type,
4678          *      which is being assigned to, issue an unchecked warning if its
4679          *      type changes under erasure.
4680          *  (5) if symbol is an instance method of a raw type, issue an
4681          *      unchecked warning if its argument types change under erasure.
4682          *  If checks succeed:
4683          *    If symbol is a constant, return its constant type
4684          *    else if symbol is a method, return its result type
4685          *    otherwise return its type.
4686          *  Otherwise return errType.
4687          *
4688          *  @param tree       The syntax tree representing the identifier
4689          *  @param site       If this is a select, the type of the selected
4690          *                    expression, otherwise the type of the current class.
4691          *  @param sym        The symbol representing the identifier.
4692          *  @param env        The current environment.
4693          *  @param resultInfo    The expected result
4694          */
4695         Type checkId(JCTree tree,
4696                      Type site,
4697                      Symbol sym,
4698                      Env<AttrContext> env,
4699                      ResultInfo resultInfo) {
4700             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
4701                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
4702                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4703         }
4704 
4705         Type checkMethodIdInternal(JCTree tree,
4706                      Type site,
4707                      Symbol sym,
4708                      Env<AttrContext> env,
4709                      ResultInfo resultInfo) {
4710             if (resultInfo.pkind.contains(KindSelector.POLY)) {
4711                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
4712             } else {
4713                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4714             }
4715         }
4716 
4717         Type checkIdInternal(JCTree tree,
4718                      Type site,
4719                      Symbol sym,
4720                      Type pt,
4721                      Env<AttrContext> env,
4722                      ResultInfo resultInfo) {
4723             Type owntype; // The computed type of this identifier occurrence.
4724             switch (sym.kind) {
4725             case TYP:
4726                 // For types, the computed type equals the symbol's type,
4727                 // except for two situations:
4728                 owntype = sym.type;
4729                 if (owntype.hasTag(CLASS)) {
4730                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
4731                     Type ownOuter = owntype.getEnclosingType();
4732 
4733                     // (a) If the symbol's type is parameterized, erase it
4734                     // because no type parameters were given.
4735                     // We recover generic outer type later in visitTypeApply.
4736                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
4737                         owntype = types.erasure(owntype);
4738                     }
4739 
4740                     // (b) If the symbol's type is an inner class, then
4741                     // we have to interpret its outer type as a superclass
4742                     // of the site type. Example:
4743                     //
4744                     // class Tree<A> { class Visitor { ... } }
4745                     // class PointTree extends Tree<Point> { ... }
4746                     // ...PointTree.Visitor...
4747                     //
4748                     // Then the type of the last expression above is
4749                     // Tree<Point>.Visitor.
4750                     else if ((ownOuter.hasTag(CLASS) || ownOuter.hasTag(TYPEVAR)) && site != ownOuter) {
4751                         Type normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
4752                         if (normOuter == null) // perhaps from an import
4753                             normOuter = types.erasure(ownOuter);
4754                         if (normOuter != ownOuter)
4755                             owntype = new ClassType(
4756                                 normOuter, List.nil(), owntype.tsym,
4757                                 owntype.getMetadata());
4758                     }
4759                 }
4760                 break;
4761             case VAR:
4762                 VarSymbol v = (VarSymbol)sym;
4763 
4764                 if (env.info.enclVar != null
4765                         && v.type.hasTag(NONE)) {
4766                     //self reference to implicitly typed variable declaration
4767                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
4768                     return tree.type = v.type = types.createErrorType(v.type);
4769                 }
4770 
4771                 // Test (4): if symbol is an instance field of a raw type,
4772                 // which is being assigned to, issue an unchecked warning if
4773                 // its type changes under erasure.
4774                 if (KindSelector.ASG.subset(pkind()) &&
4775                     v.owner.kind == TYP &&
4776                     (v.flags() & STATIC) == 0 &&
4777                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4778                     Type s = types.asOuterSuper(site, v.owner);
4779                     if (s != null &&
4780                         s.isRaw() &&
4781                         !types.isSameType(v.type, v.erasure(types))) {
4782                         chk.warnUnchecked(tree.pos(), LintWarnings.UncheckedAssignToVar(v, s));
4783                     }
4784                 }
4785                 // The computed type of a variable is the type of the
4786                 // variable symbol, taken as a member of the site type.
4787                 owntype = (sym.owner.kind == TYP &&
4788                            sym.name != names._this && sym.name != names._super)
4789                     ? types.memberType(site, sym)
4790                     : sym.type;
4791 
4792                 // If the variable is a constant, record constant value in
4793                 // computed type.
4794                 if (v.getConstValue() != null && isStaticReference(tree))
4795                     owntype = owntype.constType(v.getConstValue());
4796 
4797                 if (resultInfo.pkind == KindSelector.VAL) {
4798                     owntype = capture(owntype); // capture "names as expressions"
4799                 }
4800                 break;
4801             case MTH: {
4802                 owntype = checkMethod(site, sym,
4803                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
4804                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
4805                         resultInfo.pt.getTypeArguments());
4806                 chk.checkRestricted(tree.pos(), sym);
4807                 break;
4808             }
4809             case PCK: case ERR:
4810                 owntype = sym.type;
4811                 break;
4812             default:
4813                 throw new AssertionError("unexpected kind: " + sym.kind +
4814                                          " in tree " + tree);
4815             }
4816 
4817             // Emit a `deprecation' warning if symbol is deprecated.
4818             // (for constructors (but not for constructor references), the error
4819             // was given when the constructor was resolved)
4820 
4821             if (sym.name != names.init || tree.hasTag(REFERENCE)) {
4822                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
4823                 chk.checkSunAPI(tree.pos(), sym);
4824                 chk.checkProfile(tree.pos(), sym);
4825                 chk.checkPreview(tree.pos(), env.info.scope.owner, site, sym);
4826             }
4827 
4828             if (pt.isErroneous()) {
4829                 owntype = types.createErrorType(owntype);
4830             }
4831 
4832             // If symbol is a variable, check that its type and
4833             // kind are compatible with the prototype and protokind.
4834             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
4835         }
4836 
4837         /** Check that variable is initialized and evaluate the variable's
4838          *  initializer, if not yet done. Also check that variable is not
4839          *  referenced before it is defined.
4840          *  @param tree    The tree making up the variable reference.
4841          *  @param env     The current environment.
4842          *  @param v       The variable's symbol.
4843          */
4844         private void checkInit(JCTree tree,
4845                                Env<AttrContext> env,
4846                                VarSymbol v,
4847                                boolean onlyWarning) {
4848             // A forward reference is diagnosed if the declaration position
4849             // of the variable is greater than the current tree position
4850             // and the tree and variable definition occur in the same class
4851             // definition.  Note that writes don't count as references.
4852             // This check applies only to class and instance
4853             // variables.  Local variables follow different scope rules,
4854             // and are subject to definite assignment checking.
4855             Env<AttrContext> initEnv = enclosingInitEnv(env);
4856             if (initEnv != null &&
4857                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
4858                 v.owner.kind == TYP &&
4859                 v.owner == env.info.scope.owner.enclClass() &&
4860                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
4861                 (!env.tree.hasTag(ASSIGN) ||
4862                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
4863                 if (!onlyWarning || isStaticEnumField(v)) {
4864                     Error errkey = (initEnv.info.enclVar == v) ?
4865                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
4866                     log.error(tree.pos(), errkey);
4867                 } else if (useBeforeDeclarationWarning) {
4868                     Warning warnkey = (initEnv.info.enclVar == v) ?
4869                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
4870                     log.warning(tree.pos(), warnkey);
4871                 }
4872             }
4873 
4874             v.getConstValue(); // ensure initializer is evaluated
4875 
4876             checkEnumInitializer(tree, env, v);
4877         }
4878 
4879         /**
4880          * Returns the enclosing init environment associated with this env (if any). An init env
4881          * can be either a field declaration env or a static/instance initializer env.
4882          */
4883         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
4884             while (true) {
4885                 switch (env.tree.getTag()) {
4886                     case VARDEF:
4887                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
4888                         if (vdecl.sym.owner.kind == TYP) {
4889                             //field
4890                             return env;
4891                         }
4892                         break;
4893                     case BLOCK:
4894                         if (env.next.tree.hasTag(CLASSDEF)) {
4895                             //instance/static initializer
4896                             return env;
4897                         }
4898                         break;
4899                     case METHODDEF:
4900                     case CLASSDEF:
4901                     case TOPLEVEL:
4902                         return null;
4903                 }
4904                 Assert.checkNonNull(env.next);
4905                 env = env.next;
4906             }
4907         }
4908 
4909         /**
4910          * Check for illegal references to static members of enum.  In
4911          * an enum type, constructors and initializers may not
4912          * reference its static members unless they are constant.
4913          *
4914          * @param tree    The tree making up the variable reference.
4915          * @param env     The current environment.
4916          * @param v       The variable's symbol.
4917          * @jls 8.9 Enum Types
4918          */
4919         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
4920             // JLS:
4921             //
4922             // "It is a compile-time error to reference a static field
4923             // of an enum type that is not a compile-time constant
4924             // (15.28) from constructors, instance initializer blocks,
4925             // or instance variable initializer expressions of that
4926             // type. It is a compile-time error for the constructors,
4927             // instance initializer blocks, or instance variable
4928             // initializer expressions of an enum constant e to refer
4929             // to itself or to an enum constant of the same type that
4930             // is declared to the right of e."
4931             if (isStaticEnumField(v)) {
4932                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
4933 
4934                 if (enclClass == null || enclClass.owner == null)
4935                     return;
4936 
4937                 // See if the enclosing class is the enum (or a
4938                 // subclass thereof) declaring v.  If not, this
4939                 // reference is OK.
4940                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
4941                     return;
4942 
4943                 // If the reference isn't from an initializer, then
4944                 // the reference is OK.
4945                 if (!Resolve.isInitializer(env))
4946                     return;
4947 
4948                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
4949             }
4950         }
4951 
4952         /** Is the given symbol a static, non-constant field of an Enum?
4953          *  Note: enum literals should not be regarded as such
4954          */
4955         private boolean isStaticEnumField(VarSymbol v) {
4956             return Flags.isEnum(v.owner) &&
4957                    Flags.isStatic(v) &&
4958                    !Flags.isConstant(v) &&
4959                    v.name != names._class;
4960         }
4961 
4962     /**
4963      * Check that method arguments conform to its instantiation.
4964      **/
4965     public Type checkMethod(Type site,
4966                             final Symbol sym,
4967                             ResultInfo resultInfo,
4968                             Env<AttrContext> env,
4969                             final List<JCExpression> argtrees,
4970                             List<Type> argtypes,
4971                             List<Type> typeargtypes) {
4972         // Test (5): if symbol is an instance method of a raw type, issue
4973         // an unchecked warning if its argument types change under erasure.
4974         if ((sym.flags() & STATIC) == 0 &&
4975             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4976             Type s = types.asOuterSuper(site, sym.owner);
4977             if (s != null && s.isRaw() &&
4978                 !types.isSameTypes(sym.type.getParameterTypes(),
4979                                    sym.erasure(types).getParameterTypes())) {
4980                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedCallMbrOfRawType(sym, s));
4981             }
4982         }
4983 
4984         if (env.info.defaultSuperCallSite != null) {
4985             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
4986                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
4987                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
4988                 List<MethodSymbol> icand_sup =
4989                         types.interfaceCandidates(sup, (MethodSymbol)sym);
4990                 if (icand_sup.nonEmpty() &&
4991                         icand_sup.head != sym &&
4992                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
4993                     log.error(env.tree.pos(),
4994                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
4995                     break;
4996                 }
4997             }
4998             env.info.defaultSuperCallSite = null;
4999         }
5000 
5001         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
5002             JCMethodInvocation app = (JCMethodInvocation)env.tree;
5003             if (app.meth.hasTag(SELECT) &&
5004                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
5005                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
5006             }
5007         }
5008 
5009         // Compute the identifier's instantiated type.
5010         // For methods, we need to compute the instance type by
5011         // Resolve.instantiate from the symbol's type as well as
5012         // any type arguments and value arguments.
5013         Warner noteWarner = new Warner();
5014         try {
5015             Type owntype = rs.checkMethod(
5016                     env,
5017                     site,
5018                     sym,
5019                     resultInfo,
5020                     argtypes,
5021                     typeargtypes,
5022                     noteWarner);
5023 
5024             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
5025                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
5026 
5027             argtypes = argtypes.map(checkDeferredMap);
5028 
5029             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
5030                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedMethInvocationApplied(kindName(sym),
5031                         sym.name,
5032                         rs.methodArguments(sym.type.getParameterTypes()),
5033                         rs.methodArguments(argtypes.map(checkDeferredMap)),
5034                         kindName(sym.location()),
5035                         sym.location()));
5036                 if (resultInfo.pt != Infer.anyPoly ||
5037                         !owntype.hasTag(METHOD) ||
5038                         !owntype.isPartial()) {
5039                     //if this is not a partially inferred method type, erase return type. Otherwise,
5040                     //erasure is carried out in PartiallyInferredMethodType.check().
5041                     owntype = new MethodType(owntype.getParameterTypes(),
5042                             types.erasure(owntype.getReturnType()),
5043                             types.erasure(owntype.getThrownTypes()),
5044                             syms.methodClass);
5045                 }
5046             }
5047 
5048             PolyKind pkind = (sym.type.hasTag(FORALL) &&
5049                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
5050                  PolyKind.POLY : PolyKind.STANDALONE;
5051             TreeInfo.setPolyKind(env.tree, pkind);
5052 
5053             return (resultInfo.pt == Infer.anyPoly) ?
5054                     owntype :
5055                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
5056                             resultInfo.checkContext.inferenceContext());
5057         } catch (Infer.InferenceException ex) {
5058             //invalid target type - propagate exception outwards or report error
5059             //depending on the current check context
5060             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
5061             return types.createErrorType(site);
5062         } catch (Resolve.InapplicableMethodException ex) {
5063             final JCDiagnostic diag = ex.getDiagnostic();
5064             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
5065                 @Override
5066                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
5067                     return new Pair<>(sym, diag);
5068                 }
5069             };
5070             List<Type> argtypes2 = argtypes.map(
5071                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
5072             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
5073                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
5074             log.report(errDiag);
5075             return types.createErrorType(site);
5076         }
5077     }
5078 
5079     public void visitLiteral(JCLiteral tree) {
5080         result = check(tree, litType(tree.typetag).constType(tree.value),
5081                 KindSelector.VAL, resultInfo);
5082     }
5083     //where
5084     /** Return the type of a literal with given type tag.
5085      */
5086     Type litType(TypeTag tag) {
5087         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
5088     }
5089 
5090     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5091         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5092     }
5093 
5094     public void visitTypeArray(JCArrayTypeTree tree) {
5095         Type etype = attribType(tree.elemtype, env);
5096         Type type = new ArrayType(etype, syms.arrayClass);
5097         result = check(tree, type, KindSelector.TYP, resultInfo);
5098     }
5099 
5100     /** Visitor method for parameterized types.
5101      *  Bound checking is left until later, since types are attributed
5102      *  before supertype structure is completely known
5103      */
5104     public void visitTypeApply(JCTypeApply tree) {
5105         Type owntype = types.createErrorType(tree.type);
5106 
5107         // Attribute functor part of application and make sure it's a class.
5108         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5109 
5110         // Attribute type parameters
5111         List<Type> actuals = attribTypes(tree.arguments, env);
5112 
5113         if (clazztype.hasTag(CLASS)) {
5114             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5115             if (actuals.isEmpty()) //diamond
5116                 actuals = formals;
5117 
5118             if (actuals.length() == formals.length()) {
5119                 List<Type> a = actuals;
5120                 List<Type> f = formals;
5121                 while (a.nonEmpty()) {
5122                     a.head = a.head.withTypeVar(f.head);
5123                     a = a.tail;
5124                     f = f.tail;
5125                 }
5126                 // Compute the proper generic outer
5127                 Type clazzOuter = clazztype.getEnclosingType();
5128                 if (clazzOuter.hasTag(CLASS)) {
5129                     Type site;
5130                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5131                     if (clazz.hasTag(IDENT)) {
5132                         site = env.enclClass.sym.type;
5133                     } else if (clazz.hasTag(SELECT)) {
5134                         site = ((JCFieldAccess) clazz).selected.type;
5135                     } else throw new AssertionError(""+tree);
5136                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5137                         if (site.hasTag(CLASS) || site.hasTag(TYPEVAR))
5138                             site = types.asEnclosingSuper(site, clazzOuter.tsym);
5139                         if (site == null)
5140                             site = types.erasure(clazzOuter);
5141                         clazzOuter = site;
5142                     }
5143                 }
5144                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5145                                         clazztype.getMetadata());
5146             } else {
5147                 if (formals.length() != 0) {
5148                     log.error(tree.pos(),
5149                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5150                 } else {
5151                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5152                 }
5153                 owntype = types.createErrorType(tree.type);
5154             }
5155         } else if (clazztype.hasTag(ERROR)) {
5156             ErrorType parameterizedErroneous =
5157                     new ErrorType(clazztype.getOriginalType(),
5158                                   clazztype.tsym,
5159                                   clazztype.getMetadata());
5160 
5161             parameterizedErroneous.typarams_field = actuals;
5162             owntype = parameterizedErroneous;
5163         }
5164         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5165     }
5166 
5167     public void visitTypeUnion(JCTypeUnion tree) {
5168         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5169         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5170         for (JCExpression typeTree : tree.alternatives) {
5171             Type ctype = attribType(typeTree, env);
5172             ctype = chk.checkType(typeTree.pos(),
5173                           chk.checkClassType(typeTree.pos(), ctype),
5174                           syms.throwableType);
5175             if (!ctype.isErroneous()) {
5176                 //check that alternatives of a union type are pairwise
5177                 //unrelated w.r.t. subtyping
5178                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5179                     for (Type t : multicatchTypes) {
5180                         boolean sub = types.isSubtype(ctype, t);
5181                         boolean sup = types.isSubtype(t, ctype);
5182                         if (sub || sup) {
5183                             //assume 'a' <: 'b'
5184                             Type a = sub ? ctype : t;
5185                             Type b = sub ? t : ctype;
5186                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5187                         }
5188                     }
5189                 }
5190                 multicatchTypes.append(ctype);
5191                 if (all_multicatchTypes != null)
5192                     all_multicatchTypes.append(ctype);
5193             } else {
5194                 if (all_multicatchTypes == null) {
5195                     all_multicatchTypes = new ListBuffer<>();
5196                     all_multicatchTypes.appendList(multicatchTypes);
5197                 }
5198                 all_multicatchTypes.append(ctype);
5199             }
5200         }
5201         Type t = check(tree, types.lub(multicatchTypes.toList()),
5202                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5203         if (t.hasTag(CLASS)) {
5204             List<Type> alternatives =
5205                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5206             t = new UnionClassType((ClassType) t, alternatives);
5207         }
5208         tree.type = result = t;
5209     }
5210 
5211     public void visitTypeIntersection(JCTypeIntersection tree) {
5212         attribTypes(tree.bounds, env);
5213         tree.type = result = checkIntersection(tree, tree.bounds);
5214     }
5215 
5216     public void visitTypeParameter(JCTypeParameter tree) {
5217         TypeVar typeVar = (TypeVar) tree.type;
5218 
5219         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5220             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5221         }
5222 
5223         if (!typeVar.getUpperBound().isErroneous()) {
5224             //fixup type-parameter bound computed in 'attribTypeVariables'
5225             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5226         }
5227     }
5228 
5229     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5230         Set<Symbol> boundSet = new HashSet<>();
5231         if (bounds.nonEmpty()) {
5232             // accept class or interface or typevar as first bound.
5233             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5234             boundSet.add(types.erasure(bounds.head.type).tsym);
5235             if (bounds.head.type.isErroneous()) {
5236                 return bounds.head.type;
5237             }
5238             else if (bounds.head.type.hasTag(TYPEVAR)) {
5239                 // if first bound was a typevar, do not accept further bounds.
5240                 if (bounds.tail.nonEmpty()) {
5241                     log.error(bounds.tail.head.pos(),
5242                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5243                     return bounds.head.type;
5244                 }
5245             } else {
5246                 // if first bound was a class or interface, accept only interfaces
5247                 // as further bounds.
5248                 for (JCExpression bound : bounds.tail) {
5249                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5250                     if (bound.type.isErroneous()) {
5251                         bounds = List.of(bound);
5252                     }
5253                     else if (bound.type.hasTag(CLASS)) {
5254                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5255                     }
5256                 }
5257             }
5258         }
5259 
5260         if (bounds.length() == 0) {
5261             return syms.objectType;
5262         } else if (bounds.length() == 1) {
5263             return bounds.head.type;
5264         } else {
5265             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5266             // ... the variable's bound is a class type flagged COMPOUND
5267             // (see comment for TypeVar.bound).
5268             // In this case, generate a class tree that represents the
5269             // bound class, ...
5270             JCExpression extending;
5271             List<JCExpression> implementing;
5272             if (!bounds.head.type.isInterface()) {
5273                 extending = bounds.head;
5274                 implementing = bounds.tail;
5275             } else {
5276                 extending = null;
5277                 implementing = bounds;
5278             }
5279             JCClassDecl cd = make.at(tree).ClassDef(
5280                 make.Modifiers(PUBLIC | ABSTRACT),
5281                 names.empty, List.nil(),
5282                 extending, implementing, List.nil());
5283 
5284             ClassSymbol c = (ClassSymbol)owntype.tsym;
5285             Assert.check((c.flags() & COMPOUND) != 0);
5286             cd.sym = c;
5287             c.sourcefile = env.toplevel.sourcefile;
5288 
5289             // ... and attribute the bound class
5290             c.flags_field |= UNATTRIBUTED;
5291             Env<AttrContext> cenv = enter.classEnv(cd, env);
5292             typeEnvs.put(c, cenv);
5293             attribClass(c);
5294             return owntype;
5295         }
5296     }
5297 
5298     public void visitWildcard(JCWildcard tree) {
5299         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5300         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5301             ? syms.objectType
5302             : attribType(tree.inner, env);
5303         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
5304                                               tree.kind.kind,
5305                                               syms.boundClass),
5306                 KindSelector.TYP, resultInfo);
5307     }
5308 
5309     public void visitAnnotation(JCAnnotation tree) {
5310         Assert.error("should be handled in annotate");
5311     }
5312 
5313     @Override
5314     public void visitModifiers(JCModifiers tree) {
5315         //error recovery only:
5316         Assert.check(resultInfo.pkind == KindSelector.ERR);
5317 
5318         attribAnnotationTypes(tree.annotations, env);
5319     }
5320 
5321     public void visitAnnotatedType(JCAnnotatedType tree) {
5322         attribAnnotationTypes(tree.annotations, env);
5323         Type underlyingType = attribTree(tree.underlyingType, env, resultInfo);
5324         if (underlyingType.getTag() == PACKAGE || underlyingType.getTag() == VOID) {
5325             result = tree.type = underlyingType;
5326         } else {
5327             Type annotatedType = underlyingType.preannotatedType();
5328 
5329             annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5330             result = tree.type = annotatedType;
5331         }
5332     }
5333 
5334     public void visitErroneous(JCErroneous tree) {
5335         if (tree.errs != null) {
5336             WriteableScope newScope = env.info.scope;
5337 
5338             if (env.tree instanceof JCClassDecl) {
5339                 Symbol fakeOwner =
5340                     new MethodSymbol(BLOCK, names.empty, null,
5341                         env.info.scope.owner);
5342                 newScope = newScope.dupUnshared(fakeOwner);
5343             }
5344 
5345             Env<AttrContext> errEnv =
5346                     env.dup(env.tree,
5347                             env.info.dup(newScope));
5348             errEnv.info.returnResult = unknownExprInfo;
5349             for (JCTree err : tree.errs)
5350                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5351         }
5352         result = tree.type = syms.errType;
5353     }
5354 
5355     /** Default visitor method for all other trees.
5356      */
5357     public void visitTree(JCTree tree) {
5358         throw new AssertionError();
5359     }
5360 
5361     /**
5362      * Attribute an env for either a top level tree or class or module declaration.
5363      */
5364     public void attrib(Env<AttrContext> env) {
5365         switch (env.tree.getTag()) {
5366             case MODULEDEF:
5367                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5368                 break;
5369             case PACKAGEDEF:
5370                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5371                 break;
5372             default:
5373                 attribClass(env.tree.pos(), env.enclClass.sym);
5374         }
5375 
5376         annotate.flush();
5377 
5378         // Now that this tree is attributed, we can calculate the Lint configuration everywhere within it
5379         lintMapper.calculateLints(env.toplevel.sourcefile, env.tree);
5380     }
5381 
5382     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5383         try {
5384             annotate.flush();
5385             attribPackage(p);
5386         } catch (CompletionFailure ex) {
5387             chk.completionError(pos, ex);
5388         }
5389     }
5390 
5391     void attribPackage(PackageSymbol p) {
5392         attribWithLint(p,
5393                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5394     }
5395 
5396     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5397         try {
5398             annotate.flush();
5399             attribModule(m);
5400         } catch (CompletionFailure ex) {
5401             chk.completionError(pos, ex);
5402         }
5403     }
5404 
5405     void attribModule(ModuleSymbol m) {
5406         attribWithLint(m, env -> attribStat(env.tree, env));
5407     }
5408 
5409     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5410         Env<AttrContext> env = typeEnvs.get(sym);
5411 
5412         Env<AttrContext> lintEnv = env;
5413         while (lintEnv.info.lint == null)
5414             lintEnv = lintEnv.next;
5415 
5416         Lint lint = lintEnv.info.lint.augment(sym);
5417 
5418         Lint prevLint = chk.setLint(lint);
5419         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5420 
5421         try {
5422             attrib.accept(env);
5423         } finally {
5424             log.useSource(prev);
5425             chk.setLint(prevLint);
5426         }
5427     }
5428 
5429     /** Main method: attribute class definition associated with given class symbol.
5430      *  reporting completion failures at the given position.
5431      *  @param pos The source position at which completion errors are to be
5432      *             reported.
5433      *  @param c   The class symbol whose definition will be attributed.
5434      */
5435     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5436         try {
5437             annotate.flush();
5438             attribClass(c);
5439         } catch (CompletionFailure ex) {
5440             chk.completionError(pos, ex);
5441         }
5442     }
5443 
5444     /** Attribute class definition associated with given class symbol.
5445      *  @param c   The class symbol whose definition will be attributed.
5446      */
5447     void attribClass(ClassSymbol c) throws CompletionFailure {
5448         if (c.type.hasTag(ERROR)) return;
5449 
5450         // Check for cycles in the inheritance graph, which can arise from
5451         // ill-formed class files.
5452         chk.checkNonCyclic(null, c.type);
5453 
5454         Type st = types.supertype(c.type);
5455         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5456             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0 &&
5457             breakTree == null) {
5458             // First, attribute superclass.
5459             if (st.hasTag(CLASS))
5460                 attribClass((ClassSymbol)st.tsym);
5461 
5462             // Next attribute owner, if it is a class.
5463             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5464                 attribClass((ClassSymbol)c.owner);
5465 
5466             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5467         }
5468 
5469         // The previous operations might have attributed the current class
5470         // if there was a cycle. So we test first whether the class is still
5471         // UNATTRIBUTED.
5472         if ((c.flags_field & UNATTRIBUTED) != 0) {
5473             c.flags_field &= ~UNATTRIBUTED;
5474 
5475             // Get environment current at the point of class definition.
5476             Env<AttrContext> env = typeEnvs.get(c);
5477 
5478             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5479             // because the annotations were not available at the time the env was created. Therefore,
5480             // we look up the environment chain for the first enclosing environment for which the
5481             // lint value is set. Typically, this is the parent env, but might be further if there
5482             // are any envs created as a result of TypeParameter nodes.
5483             Env<AttrContext> lintEnv = env;
5484             while (lintEnv.info.lint == null)
5485                 lintEnv = lintEnv.next;
5486 
5487             // Having found the enclosing lint value, we can initialize the lint value for this class
5488             env.info.lint = lintEnv.info.lint.augment(c);
5489 
5490             Lint prevLint = chk.setLint(env.info.lint);
5491             JavaFileObject prev = log.useSource(c.sourcefile);
5492             ResultInfo prevReturnRes = env.info.returnResult;
5493 
5494             try {
5495                 if (c.isSealed() &&
5496                         !c.isEnum() &&
5497                         !c.isPermittedExplicit &&
5498                         c.getPermittedSubclasses().isEmpty()) {
5499                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5500                 }
5501 
5502                 if (c.isSealed()) {
5503                     Set<Symbol> permittedTypes = new HashSet<>();
5504                     boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5505                     for (Type subType : c.getPermittedSubclasses()) {
5506                         if (subType.isErroneous()) {
5507                             // the type already caused errors, don't produce more potentially misleading errors
5508                             continue;
5509                         }
5510                         boolean isTypeVar = false;
5511                         if (subType.getTag() == TYPEVAR) {
5512                             isTypeVar = true; //error recovery
5513                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5514                                     Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subType)));
5515                         }
5516                         if (subType.tsym.isAnonymous() && !c.isEnum()) {
5517                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5518                         }
5519                         if (permittedTypes.contains(subType.tsym)) {
5520                             DiagnosticPosition pos =
5521                                     env.enclClass.permitting.stream()
5522                                             .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subType.tsym, permittedExpr, true) != null)
5523                                             .limit(2).collect(List.collector()).get(1);
5524                             log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subType)));
5525                         } else {
5526                             permittedTypes.add(subType.tsym);
5527                         }
5528                         if (sealedInUnnamed) {
5529                             if (subType.tsym.packge() != c.packge()) {
5530                                 log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5531                                         Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5532                                 );
5533                             }
5534                         } else if (subType.tsym.packge().modle != c.packge().modle) {
5535                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5536                                     Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5537                             );
5538                         }
5539                         if (subType.tsym == c.type.tsym || types.isSuperType(subType, c.type)) {
5540                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, ((JCClassDecl)env.tree).permitting),
5541                                     Errors.InvalidPermitsClause(
5542                                             subType.tsym == c.type.tsym ?
5543                                                     Fragments.MustNotBeSameClass :
5544                                                     Fragments.MustNotBeSupertype(subType)
5545                                     )
5546                             );
5547                         } else if (!isTypeVar) {
5548                             boolean thisIsASuper = types.directSupertypes(subType)
5549                                                         .stream()
5550                                                         .anyMatch(d -> d.tsym == c);
5551                             if (!thisIsASuper) {
5552                                 if(c.isInterface()) {
5553                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5554                                             Errors.InvalidPermitsClause(Fragments.DoesntImplementSealed(kindName(subType.tsym), subType)));
5555                                 } else {
5556                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5557                                             Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subType)));
5558                                 }
5559                             }
5560                         }
5561                     }
5562                 }
5563 
5564                 List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5565                                                       .stream()
5566                                                       .filter(s -> s.tsym.isSealed())
5567                                                       .map(s -> (ClassSymbol) s.tsym)
5568                                                       .collect(List.collector());
5569 
5570                 if (sealedSupers.isEmpty()) {
5571                     if ((c.flags_field & Flags.NON_SEALED) != 0) {
5572                         boolean hasErrorSuper = false;
5573 
5574                         hasErrorSuper |= types.directSupertypes(c.type)
5575                                               .stream()
5576                                               .anyMatch(s -> s.tsym.kind == Kind.ERR);
5577 
5578                         ClassType ct = (ClassType) c.type;
5579 
5580                         hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5581 
5582                         if (!hasErrorSuper) {
5583                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5584                         }
5585                     }
5586                 } else {
5587                     if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5588                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5589                     }
5590 
5591                     if (!c.type.isCompound()) {
5592                         for (ClassSymbol supertypeSym : sealedSupers) {
5593                             if (!supertypeSym.isPermittedSubclass(c.type.tsym)) {
5594                                 log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5595                             }
5596                         }
5597                         if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5598                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5599                                     c.isInterface() ?
5600                                             Errors.NonSealedOrSealedExpected :
5601                                             Errors.NonSealedSealedOrFinalExpected);
5602                         }
5603                     }
5604                 }
5605 
5606                 env.info.returnResult = null;
5607                 // java.lang.Enum may not be subclassed by a non-enum
5608                 if (st.tsym == syms.enumSym &&
5609                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5610                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5611 
5612                 // Enums may not be extended by source-level classes
5613                 if (st.tsym != null &&
5614                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5615                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5616                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5617                 }
5618 
5619                 if (rs.isSerializable(c.type)) {
5620                     env.info.isSerializable = true;
5621                 }
5622 
5623                 if (c.isValueClass()) {
5624                     Assert.check(env.tree.hasTag(CLASSDEF));
5625                     chk.checkConstraintsOfValueClass((JCClassDecl) env.tree, c);
5626                 }
5627 
5628                 attribClassBody(env, c);
5629 
5630                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5631                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5632                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5633                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5634 
5635                 if (c.isImplicit()) {
5636                     chk.checkHasMain(env.tree.pos(), c);
5637                 }
5638             } finally {
5639                 env.info.returnResult = prevReturnRes;
5640                 log.useSource(prev);
5641                 chk.setLint(prevLint);
5642             }
5643 
5644         }
5645     }
5646 
5647     public void visitImport(JCImport tree) {
5648         // nothing to do
5649     }
5650 
5651     public void visitModuleDef(JCModuleDecl tree) {
5652         tree.sym.completeUsesProvides();
5653         ModuleSymbol msym = tree.sym;
5654         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5655         Lint prevLint = chk.setLint(lint);
5656         try {
5657             chk.checkModuleName(tree);
5658             chk.checkDeprecatedAnnotation(tree, msym);
5659         } finally {
5660             chk.setLint(prevLint);
5661         }
5662     }
5663 
5664     /** Finish the attribution of a class. */
5665     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5666         JCClassDecl tree = (JCClassDecl)env.tree;
5667         Assert.check(c == tree.sym);
5668 
5669         // Validate type parameters, supertype and interfaces.
5670         attribStats(tree.typarams, env);
5671         if (!c.isAnonymous()) {
5672             //already checked if anonymous
5673             chk.validate(tree.typarams, env);
5674             chk.validate(tree.extending, env);
5675             chk.validate(tree.implementing, env);
5676         }
5677 
5678         chk.checkRequiresIdentity(tree, env.info.lint);
5679 
5680         c.markAbstractIfNeeded(types);
5681 
5682         // If this is a non-abstract class, check that it has no abstract
5683         // methods or unimplemented methods of an implemented interface.
5684         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
5685             chk.checkAllDefined(tree.pos(), c);
5686         }
5687 
5688         if ((c.flags() & ANNOTATION) != 0) {
5689             if (tree.implementing.nonEmpty())
5690                 log.error(tree.implementing.head.pos(),
5691                           Errors.CantExtendIntfAnnotation);
5692             if (tree.typarams.nonEmpty()) {
5693                 log.error(tree.typarams.head.pos(),
5694                           Errors.IntfAnnotationCantHaveTypeParams(c));
5695             }
5696 
5697             // If this annotation type has a @Repeatable, validate
5698             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
5699             // If this annotation type has a @Repeatable, validate
5700             if (repeatable != null) {
5701                 // get diagnostic position for error reporting
5702                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
5703                 Assert.checkNonNull(cbPos);
5704 
5705                 chk.validateRepeatable(c, repeatable, cbPos);
5706             }
5707         } else {
5708             try {
5709                 // Check that all extended classes and interfaces
5710                 // are compatible (i.e. no two define methods with same arguments
5711                 // yet different return types).  (JLS 8.4.8.3)
5712                 chk.checkCompatibleSupertypes(tree.pos(), c.type);
5713                 chk.checkDefaultMethodClashes(tree.pos(), c.type);
5714                 chk.checkPotentiallyAmbiguousOverloads(tree, c.type);
5715             } catch (CompletionFailure cf) {
5716                 chk.completionError(tree.pos(), cf);
5717             }
5718         }
5719 
5720         // Check that class does not import the same parameterized interface
5721         // with two different argument lists.
5722         chk.checkClassBounds(tree.pos(), c.type);
5723 
5724         tree.type = c.type;
5725 
5726         for (List<JCTypeParameter> l = tree.typarams;
5727              l.nonEmpty(); l = l.tail) {
5728              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
5729         }
5730 
5731         // Check that a generic class doesn't extend Throwable
5732         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
5733             log.error(tree.extending.pos(), Errors.GenericThrowable);
5734 
5735         // Check that all methods which implement some
5736         // method conform to the method they implement.
5737         chk.checkImplementations(tree);
5738 
5739         //check that a resource implementing AutoCloseable cannot throw InterruptedException
5740         checkAutoCloseable(env, tree, false);
5741 
5742         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
5743             // Attribute declaration
5744             attribStat(l.head, env);
5745             // Check that declarations in inner classes are not static (JLS 8.1.2)
5746             // Make an exception for static constants.
5747             if (!allowRecords &&
5748                     c.owner.kind != PCK &&
5749                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
5750                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
5751                 VarSymbol sym = null;
5752                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
5753                 if (sym == null ||
5754                         sym.kind != VAR ||
5755                         sym.getConstValue() == null)
5756                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
5757             }
5758         }
5759 
5760         // Check for proper placement of super()/this() calls.
5761         chk.checkSuperInitCalls(tree);
5762 
5763         // Check for cycles among non-initial constructors.
5764         chk.checkCyclicConstructors(tree);
5765 
5766         // Check for cycles among annotation elements.
5767         chk.checkNonCyclicElements(tree);
5768 
5769         // Check for proper use of serialVersionUID and other
5770         // serialization-related fields and methods
5771         if (env.info.lint.isEnabled(LintCategory.SERIAL)
5772                 && rs.isSerializable(c.type)
5773                 && !c.isAnonymous()) {
5774             chk.checkSerialStructure(env, tree, c);
5775         }
5776         // Correctly organize the positions of the type annotations
5777         typeAnnotations.organizeTypeAnnotationsBodies(tree);
5778 
5779         // Check type annotations applicability rules
5780         validateTypeAnnotations(tree, false);
5781     }
5782         // where
5783         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
5784         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
5785             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
5786                 if (types.isSameType(al.head.annotationType.type, t))
5787                     return al.head.pos();
5788             }
5789 
5790             return null;
5791         }
5792 
5793     private Type capture(Type type) {
5794         return types.capture(type);
5795     }
5796 
5797     private void setupImplicitlyTypedVariable(JCVariableDecl tree, Type type) {
5798         Assert.check(tree.isImplicitlyTyped());
5799 
5800         type.complete();
5801 
5802         if (tree.vartype == null) {
5803             return ;
5804         }
5805 
5806         Assert.check(tree.vartype.hasTag(VARTYPE));
5807 
5808         JCVarType vartype = (JCVarType) tree.vartype;
5809 
5810         vartype.type = type;
5811     }
5812 
5813     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
5814         tree.accept(new TypeAnnotationsValidator(sigOnly));
5815     }
5816     //where
5817     private final class TypeAnnotationsValidator extends TreeScanner {
5818 
5819         private final boolean sigOnly;
5820         public TypeAnnotationsValidator(boolean sigOnly) {
5821             this.sigOnly = sigOnly;
5822         }
5823 
5824         public void visitAnnotation(JCAnnotation tree) {
5825             chk.validateTypeAnnotation(tree, null, false);
5826             super.visitAnnotation(tree);
5827         }
5828         public void visitAnnotatedType(JCAnnotatedType tree) {
5829             if (!tree.underlyingType.type.isErroneous()) {
5830                 super.visitAnnotatedType(tree);
5831             }
5832         }
5833         public void visitTypeParameter(JCTypeParameter tree) {
5834             chk.validateTypeAnnotations(tree.annotations, tree.type.tsym, true);
5835             scan(tree.bounds);
5836             // Don't call super.
5837             // This is needed because above we call validateTypeAnnotation with
5838             // false, which would forbid annotations on type parameters.
5839             // super.visitTypeParameter(tree);
5840         }
5841         public void visitMethodDef(JCMethodDecl tree) {
5842             if (tree.recvparam != null &&
5843                     !tree.recvparam.vartype.type.isErroneous()) {
5844                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
5845             }
5846             if (tree.restype != null && tree.restype.type != null) {
5847                 validateAnnotatedType(tree.restype, tree.restype.type);
5848             }
5849             if (sigOnly) {
5850                 scan(tree.mods);
5851                 scan(tree.restype);
5852                 scan(tree.typarams);
5853                 scan(tree.recvparam);
5854                 scan(tree.params);
5855                 scan(tree.thrown);
5856             } else {
5857                 scan(tree.defaultValue);
5858                 scan(tree.body);
5859             }
5860         }
5861         public void visitVarDef(final JCVariableDecl tree) {
5862             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
5863             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
5864                 validateAnnotatedType(tree.vartype, tree.sym.type);
5865             scan(tree.mods);
5866             scan(tree.vartype);
5867             if (!sigOnly) {
5868                 scan(tree.init);
5869             }
5870         }
5871         public void visitTypeCast(JCTypeCast tree) {
5872             if (tree.clazz != null && tree.clazz.type != null)
5873                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5874             super.visitTypeCast(tree);
5875         }
5876         public void visitTypeTest(JCInstanceOf tree) {
5877             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
5878                 validateAnnotatedType(tree.pattern, tree.pattern.type);
5879             super.visitTypeTest(tree);
5880         }
5881         public void visitNewClass(JCNewClass tree) {
5882             if (tree.clazz != null && tree.clazz.type != null) {
5883                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
5884                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
5885                             tree.clazz.type.tsym);
5886                 }
5887                 if (tree.def != null) {
5888                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
5889                 }
5890 
5891                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5892             }
5893             super.visitNewClass(tree);
5894         }
5895         public void visitNewArray(JCNewArray tree) {
5896             if (tree.elemtype != null && tree.elemtype.type != null) {
5897                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
5898                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
5899                             tree.elemtype.type.tsym);
5900                 }
5901                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
5902             }
5903             super.visitNewArray(tree);
5904         }
5905         public void visitClassDef(JCClassDecl tree) {
5906             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
5907             if (sigOnly) {
5908                 scan(tree.mods);
5909                 scan(tree.typarams);
5910                 scan(tree.extending);
5911                 scan(tree.implementing);
5912             }
5913             for (JCTree member : tree.defs) {
5914                 if (member.hasTag(Tag.CLASSDEF)) {
5915                     continue;
5916                 }
5917                 scan(member);
5918             }
5919         }
5920         public void visitBlock(JCBlock tree) {
5921             if (!sigOnly) {
5922                 scan(tree.stats);
5923             }
5924         }
5925 
5926         /* I would want to model this after
5927          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
5928          * and override visitSelect and visitTypeApply.
5929          * However, we only set the annotated type in the top-level type
5930          * of the symbol.
5931          * Therefore, we need to override each individual location where a type
5932          * can occur.
5933          */
5934         private void validateAnnotatedType(final JCTree errtree, final Type type) {
5935             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
5936 
5937             if (type.isPrimitiveOrVoid()) {
5938                 return;
5939             }
5940 
5941             JCTree enclTr = errtree;
5942             Type enclTy = type;
5943 
5944             boolean repeat = true;
5945             while (repeat) {
5946                 if (enclTr.hasTag(TYPEAPPLY)) {
5947                     List<Type> tyargs = enclTy.getTypeArguments();
5948                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
5949                     if (trargs.length() > 0) {
5950                         // Nothing to do for diamonds
5951                         if (tyargs.length() == trargs.length()) {
5952                             for (int i = 0; i < tyargs.length(); ++i) {
5953                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
5954                             }
5955                         }
5956                         // If the lengths don't match, it's either a diamond
5957                         // or some nested type that redundantly provides
5958                         // type arguments in the tree.
5959                     }
5960 
5961                     // Look at the clazz part of a generic type
5962                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
5963                 }
5964 
5965                 if (enclTr.hasTag(SELECT)) {
5966                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
5967                     if (enclTy != null &&
5968                             !enclTy.hasTag(NONE)) {
5969                         enclTy = enclTy.getEnclosingType();
5970                     }
5971                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
5972                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
5973                     if (enclTy == null || enclTy.hasTag(NONE)) {
5974                         ListBuffer<Attribute.TypeCompound> onlyTypeAnnotationsBuf = new ListBuffer<>();
5975                         for (JCAnnotation an : at.getAnnotations()) {
5976                             if (chk.isTypeAnnotation(an, false)) {
5977                                 onlyTypeAnnotationsBuf.add((Attribute.TypeCompound) an.attribute);
5978                             }
5979                         }
5980                         List<Attribute.TypeCompound> onlyTypeAnnotations = onlyTypeAnnotationsBuf.toList();
5981                         if (!onlyTypeAnnotations.isEmpty()) {
5982                             Fragment annotationFragment = onlyTypeAnnotations.size() == 1 ?
5983                                     Fragments.TypeAnnotation1(onlyTypeAnnotations.head) :
5984                                     Fragments.TypeAnnotation(onlyTypeAnnotations);
5985                             JCDiagnostic.AnnotatedType annotatedType = new JCDiagnostic.AnnotatedType(
5986                                     type.stripMetadata().annotatedType(onlyTypeAnnotations));
5987                             log.error(at.underlyingType.pos(), Errors.TypeAnnotationInadmissible(annotationFragment,
5988                                     type.tsym.owner, annotatedType));
5989                         }
5990                         repeat = false;
5991                     }
5992                     enclTr = at.underlyingType;
5993                     // enclTy doesn't need to be changed
5994                 } else if (enclTr.hasTag(IDENT)) {
5995                     repeat = false;
5996                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
5997                     JCWildcard wc = (JCWildcard) enclTr;
5998                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
5999                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
6000                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
6001                     } else {
6002                         // Nothing to do for UNBOUND
6003                     }
6004                     repeat = false;
6005                 } else if (enclTr.hasTag(TYPEARRAY)) {
6006                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
6007                     validateAnnotatedType(art.getType(), art.elemtype.type);
6008                     repeat = false;
6009                 } else if (enclTr.hasTag(TYPEUNION)) {
6010                     JCTypeUnion ut = (JCTypeUnion) enclTr;
6011                     for (JCTree t : ut.getTypeAlternatives()) {
6012                         validateAnnotatedType(t, t.type);
6013                     }
6014                     repeat = false;
6015                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
6016                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
6017                     for (JCTree t : it.getBounds()) {
6018                         validateAnnotatedType(t, t.type);
6019                     }
6020                     repeat = false;
6021                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
6022                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
6023                     repeat = false;
6024                 } else {
6025                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
6026                             " within: "+ errtree + " with kind: " + errtree.getKind());
6027                 }
6028             }
6029         }
6030 
6031         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
6032                 Symbol sym) {
6033             // Ensure that no declaration annotations are present.
6034             // Note that a tree type might be an AnnotatedType with
6035             // empty annotations, if only declaration annotations were given.
6036             // This method will raise an error for such a type.
6037             for (JCAnnotation ai : annotations) {
6038                 if (!ai.type.isErroneous() &&
6039                         typeAnnotations.annotationTargetType(ai, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
6040                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
6041                 }
6042             }
6043         }
6044     }
6045 
6046     // <editor-fold desc="post-attribution visitor">
6047 
6048     /**
6049      * Handle missing types/symbols in an AST. This routine is useful when
6050      * the compiler has encountered some errors (which might have ended up
6051      * terminating attribution abruptly); if the compiler is used in fail-over
6052      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
6053      * prevents NPE to be propagated during subsequent compilation steps.
6054      */
6055     public void postAttr(JCTree tree) {
6056         new PostAttrAnalyzer().scan(tree);
6057     }
6058 
6059     class PostAttrAnalyzer extends TreeScanner {
6060 
6061         private void initTypeIfNeeded(JCTree that) {
6062             if (that.type == null) {
6063                 if (that.hasTag(METHODDEF)) {
6064                     that.type = dummyMethodType((JCMethodDecl)that);
6065                 } else {
6066                     that.type = syms.unknownType;
6067                 }
6068             }
6069         }
6070 
6071         /* Construct a dummy method type. If we have a method declaration,
6072          * and the declared return type is void, then use that return type
6073          * instead of UNKNOWN to avoid spurious error messages in lambda
6074          * bodies (see:JDK-8041704).
6075          */
6076         private Type dummyMethodType(JCMethodDecl md) {
6077             Type restype = syms.unknownType;
6078             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
6079                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
6080                 if (prim.typetag == VOID)
6081                     restype = syms.voidType;
6082             }
6083             return new MethodType(List.nil(), restype,
6084                                   List.nil(), syms.methodClass);
6085         }
6086         private Type dummyMethodType() {
6087             return dummyMethodType(null);
6088         }
6089 
6090         @Override
6091         public void scan(JCTree tree) {
6092             if (tree == null) return;
6093             if (tree instanceof JCExpression) {
6094                 initTypeIfNeeded(tree);
6095             }
6096             super.scan(tree);
6097         }
6098 
6099         @Override
6100         public void visitIdent(JCIdent that) {
6101             if (that.sym == null) {
6102                 that.sym = syms.unknownSymbol;
6103             }
6104         }
6105 
6106         @Override
6107         public void visitSelect(JCFieldAccess that) {
6108             if (that.sym == null) {
6109                 that.sym = syms.unknownSymbol;
6110             }
6111             super.visitSelect(that);
6112         }
6113 
6114         @Override
6115         public void visitClassDef(JCClassDecl that) {
6116             initTypeIfNeeded(that);
6117             if (that.sym == null) {
6118                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
6119             }
6120             super.visitClassDef(that);
6121         }
6122 
6123         @Override
6124         public void visitMethodDef(JCMethodDecl that) {
6125             initTypeIfNeeded(that);
6126             if (that.sym == null) {
6127                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
6128             }
6129             super.visitMethodDef(that);
6130         }
6131 
6132         @Override
6133         public void visitVarDef(JCVariableDecl that) {
6134             initTypeIfNeeded(that);
6135             if (that.sym == null) {
6136                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
6137                 that.sym.adr = 0;
6138             }
6139             super.visitVarDef(that);
6140         }
6141 
6142         @Override
6143         public void visitBindingPattern(JCBindingPattern that) {
6144             initTypeIfNeeded(that);
6145             initTypeIfNeeded(that.var);
6146             if (that.var.sym == null) {
6147                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6148                 that.var.sym.adr = 0;
6149             }
6150             super.visitBindingPattern(that);
6151         }
6152 
6153         @Override
6154         public void visitRecordPattern(JCRecordPattern that) {
6155             initTypeIfNeeded(that);
6156             if (that.record == null) {
6157                 that.record = new ClassSymbol(0, TreeInfo.name(that.deconstructor),
6158                                               that.type, syms.noSymbol);
6159             }
6160             if (that.fullComponentTypes == null) {
6161                 that.fullComponentTypes = List.nil();
6162             }
6163             super.visitRecordPattern(that);
6164         }
6165 
6166         @Override
6167         public void visitNewClass(JCNewClass that) {
6168             if (that.constructor == null) {
6169                 that.constructor = new MethodSymbol(0, names.init,
6170                         dummyMethodType(), syms.noSymbol);
6171             }
6172             if (that.constructorType == null) {
6173                 that.constructorType = syms.unknownType;
6174             }
6175             super.visitNewClass(that);
6176         }
6177 
6178         @Override
6179         public void visitAssignop(JCAssignOp that) {
6180             if (that.operator == null) {
6181                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6182                         -1, syms.noSymbol);
6183             }
6184             super.visitAssignop(that);
6185         }
6186 
6187         @Override
6188         public void visitBinary(JCBinary that) {
6189             if (that.operator == null) {
6190                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6191                         -1, syms.noSymbol);
6192             }
6193             super.visitBinary(that);
6194         }
6195 
6196         @Override
6197         public void visitUnary(JCUnary that) {
6198             if (that.operator == null) {
6199                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6200                         -1, syms.noSymbol);
6201             }
6202             super.visitUnary(that);
6203         }
6204 
6205         @Override
6206         public void visitReference(JCMemberReference that) {
6207             super.visitReference(that);
6208             if (that.sym == null) {
6209                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6210                         syms.noSymbol);
6211             }
6212         }
6213 
6214         @Override
6215         public void visitVarType(JCVarType that) {
6216             initTypeIfNeeded(that);
6217         }
6218     }
6219     // </editor-fold>
6220 
6221     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6222         new TreeScanner() {
6223             Symbol packge = pkg;
6224             @Override
6225             public void visitIdent(JCIdent that) {
6226                 that.sym = packge;
6227             }
6228 
6229             @Override
6230             public void visitSelect(JCFieldAccess that) {
6231                 that.sym = packge;
6232                 packge = packge.owner;
6233                 super.visitSelect(that);
6234             }
6235         }.scan(pid);
6236     }
6237 
6238 }