1 /*
   2  * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.tools.javac.comp;
  27 
  28 import java.util.*;
  29 import java.util.function.BiConsumer;
  30 import java.util.function.Consumer;
  31 import java.util.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 LocalProxyVarsGen localProxyVarsGen;
 128     final boolean captureMRefReturnType;
 129 
 130     public static Attr instance(Context context) {
 131         Attr instance = context.get(attrKey);
 132         if (instance == null)
 133             instance = new Attr(context);
 134         return instance;
 135     }
 136 
 137     @SuppressWarnings("this-escape")
 138     protected Attr(Context context) {
 139         context.put(attrKey, this);
 140 
 141         names = Names.instance(context);
 142         log = Log.instance(context);
 143         lintMapper = LintMapper.instance(context);
 144         syms = Symtab.instance(context);
 145         rs = Resolve.instance(context);
 146         operators = Operators.instance(context);
 147         chk = Check.instance(context);
 148         flow = Flow.instance(context);
 149         memberEnter = MemberEnter.instance(context);
 150         typeEnter = TypeEnter.instance(context);
 151         make = TreeMaker.instance(context);
 152         enter = Enter.instance(context);
 153         infer = Infer.instance(context);
 154         analyzer = Analyzer.instance(context);
 155         deferredAttr = DeferredAttr.instance(context);
 156         cfolder = ConstFold.instance(context);
 157         target = Target.instance(context);
 158         types = Types.instance(context);
 159         preview = Preview.instance(context);
 160         diags = JCDiagnostic.Factory.instance(context);
 161         annotate = Annotate.instance(context);
 162         typeAnnotations = TypeAnnotations.instance(context);
 163         typeEnvs = TypeEnvs.instance(context);
 164         dependencies = Dependencies.instance(context);
 165         argumentAttr = ArgumentAttr.instance(context);
 166         matchBindingsComputer = MatchBindingsComputer.instance(context);
 167         attrRecover = AttrRecover.instance(context);
 168         localProxyVarsGen = LocalProxyVarsGen.instance(context);
 169 
 170         Options options = Options.instance(context);
 171 
 172         Source source = Source.instance(context);
 173         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 174         allowRecords = Feature.RECORDS.allowedInSource(source);
 175         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 176                              Feature.PATTERN_SWITCH.allowedInSource(source);
 177         allowUnconditionalPatternsInstanceOf =
 178                              Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 179         sourceName = source.name;
 180         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 181         captureMRefReturnType = Source.Feature.ERASE_POLY_SIG_RETURN_TYPE.allowedInSource(source);
 182 
 183         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 184         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 185         unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
 186         methodAttrInfo = new MethodAttrInfo();
 187         unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
 188         unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
 189         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
 190         initBlockType = new MethodType(List.nil(), syms.voidType, List.nil(), syms.methodClass);
 191         allowValueClasses = (!preview.isPreview(Feature.VALUE_CLASSES) || preview.isEnabled()) &&
 192                 Feature.VALUE_CLASSES.allowedInSource(source);
 193     }
 194 
 195     /** Switch: reifiable types in instanceof enabled?
 196      */
 197     boolean allowReifiableTypesInInstanceof;
 198 
 199     /** Are records allowed
 200      */
 201     private final boolean allowRecords;
 202 
 203     /** Are patterns in switch allowed
 204      */
 205     private final boolean allowPatternSwitch;
 206 
 207     /** Are unconditional patterns in instanceof allowed
 208      */
 209     private final boolean allowUnconditionalPatternsInstanceOf;
 210 
 211     /** Are value classes allowed
 212      */
 213     private final boolean allowValueClasses;
 214 
 215     /**
 216      * Switch: warn about use of variable before declaration?
 217      * RFE: 6425594
 218      */
 219     boolean useBeforeDeclarationWarning;
 220 
 221     /**
 222      * Switch: name of source level; used for error reporting.
 223      */
 224     String sourceName;
 225 
 226     /** Check kind and type of given tree against protokind and prototype.
 227      *  If check succeeds, store type in tree and return it.
 228      *  If check fails, store errType in tree and return it.
 229      *  No checks are performed if the prototype is a method type.
 230      *  It is not necessary in this case since we know that kind and type
 231      *  are correct.
 232      *
 233      *  @param tree     The tree whose kind and type is checked
 234      *  @param found    The computed type of the tree
 235      *  @param ownkind  The computed kind of the tree
 236      *  @param resultInfo  The expected result of the tree
 237      */
 238     Type check(final JCTree tree,
 239                final Type found,
 240                final KindSelector ownkind,
 241                final ResultInfo resultInfo) {
 242         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 243         Type owntype;
 244         boolean shouldCheck = !found.hasTag(ERROR) &&
 245                 !resultInfo.pt.hasTag(METHOD) &&
 246                 !resultInfo.pt.hasTag(FORALL);
 247         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 248             log.error(tree.pos(),
 249                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 250                                             ownkind.kindNames()));
 251             owntype = types.createErrorType(found);
 252         } else if (inferenceContext.free(found)) {
 253             //delay the check if there are inference variables in the found type
 254             //this means we are dealing with a partially inferred poly expression
 255             owntype = shouldCheck ? resultInfo.pt : found;
 256             if (resultInfo.checkMode.installPostInferenceHook()) {
 257                 inferenceContext.addFreeTypeListener(List.of(found),
 258                         instantiatedContext -> {
 259                             ResultInfo pendingResult =
 260                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 261                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 262                         });
 263             }
 264         } else {
 265             owntype = shouldCheck ?
 266             resultInfo.check(tree, found) :
 267             found;
 268         }
 269         if (resultInfo.checkMode.updateTreeType()) {
 270             tree.type = owntype;
 271         }
 272         return owntype;
 273     }
 274 
 275     /** Is given blank final variable assignable, i.e. in a scope where it
 276      *  may be assigned to even though it is final?
 277      *  @param v      The blank final variable.
 278      *  @param env    The current environment.
 279      */
 280     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 281         Symbol owner = env.info.scope.owner;
 282            // owner refers to the innermost variable, method or
 283            // initializer block declaration at this point.
 284         boolean isAssignable =
 285             v.owner == owner
 286             ||
 287             ((owner.name == names.init ||    // i.e. we are in a constructor
 288               owner.kind == VAR ||           // i.e. we are in a variable initializer
 289               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 290              &&
 291              v.owner == owner.owner
 292              &&
 293              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 294         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 295         return isAssignable & !insideCompactConstructor;
 296     }
 297 
 298     /** Check that variable can be assigned to.
 299      *  @param pos    The current source code position.
 300      *  @param v      The assigned variable
 301      *  @param base   If the variable is referred to in a Select, the part
 302      *                to the left of the `.', null otherwise.
 303      *  @param env    The current environment.
 304      */
 305     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 306         if (v.name == names._this) {
 307             log.error(pos, Errors.CantAssignValToThis);
 308         } else 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         }
 320     }
 321 
 322     /** Does tree represent a static reference to an identifier?
 323      *  It is assumed that tree is either a SELECT or an IDENT.
 324      *  We have to weed out selects from non-type names here.
 325      *  @param tree    The candidate tree.
 326      */
 327     boolean isStaticReference(JCTree tree) {
 328         if (tree.hasTag(SELECT)) {
 329             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 330             if (lsym == null || lsym.kind != TYP) {
 331                 return false;
 332             }
 333         }
 334         return true;
 335     }
 336 
 337     /** Is this symbol a type?
 338      */
 339     static boolean isType(Symbol sym) {
 340         return sym != null && sym.kind == TYP;
 341     }
 342 
 343     /** Attribute a parsed identifier.
 344      * @param tree Parsed identifier name
 345      * @param topLevel The toplevel to use
 346      */
 347     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 348         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 349         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 350                                            syms.errSymbol.name,
 351                                            null, null, null, null);
 352         localEnv.enclClass.sym = syms.errSymbol;
 353         return attribIdent(tree, localEnv);
 354     }
 355 
 356     /** Attribute a parsed identifier.
 357      * @param tree Parsed identifier name
 358      * @param env The env to use
 359      */
 360     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 361         return tree.accept(identAttributer, env);
 362     }
 363     // where
 364         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 365         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 366             @Override @DefinedBy(Api.COMPILER_TREE)
 367             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 368                 Symbol site = visit(node.getExpression(), env);
 369                 if (site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 370                     return site;
 371                 Name name = (Name)node.getIdentifier();
 372                 if (site.kind == PCK) {
 373                     env.toplevel.packge = (PackageSymbol)site;
 374                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 375                             KindSelector.TYP_PCK);
 376                 } else {
 377                     env.enclClass.sym = (ClassSymbol)site;
 378                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 379                 }
 380             }
 381 
 382             @Override @DefinedBy(Api.COMPILER_TREE)
 383             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 384                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 385             }
 386         }
 387 
 388     public Type coerce(Type etype, Type ttype) {
 389         return cfolder.coerce(etype, ttype);
 390     }
 391 
 392     public Type attribType(JCTree node, TypeSymbol sym) {
 393         Env<AttrContext> env = typeEnvs.get(sym);
 394         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 395         return attribTree(node, localEnv, unknownTypeInfo);
 396     }
 397 
 398     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 399         // Attribute qualifying package or class.
 400         JCFieldAccess s = tree.qualid;
 401         return attribTree(s.selected, env,
 402                           new ResultInfo(tree.staticImport ?
 403                                          KindSelector.TYP : KindSelector.TYP_PCK,
 404                        Type.noType));
 405     }
 406 
 407     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 408         return attribToTree(expr, env, tree, unknownExprInfo);
 409     }
 410 
 411     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 412         return attribToTree(stmt, env, tree, statInfo);
 413     }
 414 
 415     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 416         breakTree = tree;
 417         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 418         try {
 419             deferredAttr.attribSpeculative(root, env, resultInfo,
 420                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 421                     argumentAttr.withLocalCacheContext());
 422             attrRecover.doRecovery();
 423         } catch (BreakAttr b) {
 424             return b.env;
 425         } catch (AssertionError ae) {
 426             if (ae.getCause() instanceof BreakAttr breakAttr) {
 427                 return breakAttr.env;
 428             } else {
 429                 throw ae;
 430             }
 431         } finally {
 432             breakTree = null;
 433             log.useSource(prev);
 434         }
 435         return env;
 436     }
 437 
 438     private JCTree breakTree = null;
 439 
 440     private static class BreakAttr extends RuntimeException {
 441         static final long serialVersionUID = -6924771130405446405L;
 442         private transient Env<AttrContext> env;
 443         private BreakAttr(Env<AttrContext> env) {
 444             this.env = env;
 445         }
 446     }
 447 
 448     /**
 449      * Mode controlling behavior of Attr.Check
 450      */
 451     enum CheckMode {
 452 
 453         NORMAL,
 454 
 455         /**
 456          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 457          * that the captured var cache in {@code InferenceContext} will be used in read-only
 458          * mode when performing inference checks.
 459          */
 460         NO_TREE_UPDATE {
 461             @Override
 462             public boolean updateTreeType() {
 463                 return false;
 464             }
 465         },
 466         /**
 467          * Mode signalling that caller will manage free types in tree decorations.
 468          */
 469         NO_INFERENCE_HOOK {
 470             @Override
 471             public boolean installPostInferenceHook() {
 472                 return false;
 473             }
 474         };
 475 
 476         public boolean updateTreeType() {
 477             return true;
 478         }
 479         public boolean installPostInferenceHook() {
 480             return true;
 481         }
 482     }
 483 
 484 
 485     class ResultInfo {
 486         final KindSelector pkind;
 487         final Type pt;
 488         final CheckContext checkContext;
 489         final CheckMode checkMode;
 490 
 491         ResultInfo(KindSelector pkind, Type pt) {
 492             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 493         }
 494 
 495         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 496             this(pkind, pt, chk.basicHandler, checkMode);
 497         }
 498 
 499         protected ResultInfo(KindSelector pkind,
 500                              Type pt, CheckContext checkContext) {
 501             this(pkind, pt, checkContext, CheckMode.NORMAL);
 502         }
 503 
 504         protected ResultInfo(KindSelector pkind,
 505                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 506             this.pkind = pkind;
 507             this.pt = pt;
 508             this.checkContext = checkContext;
 509             this.checkMode = checkMode;
 510         }
 511 
 512         /**
 513          * Should {@link Attr#attribTree} use the {@code ArgumentAttr} visitor instead of this one?
 514          * @param tree The tree to be type-checked.
 515          * @return true if {@code ArgumentAttr} should be used.
 516          */
 517         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 518 
 519         protected Type check(final DiagnosticPosition pos, final Type found) {
 520             return chk.checkType(pos, found, pt, checkContext);
 521         }
 522 
 523         protected ResultInfo dup(Type newPt) {
 524             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 525         }
 526 
 527         protected ResultInfo dup(CheckContext newContext) {
 528             return new ResultInfo(pkind, pt, newContext, checkMode);
 529         }
 530 
 531         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 532             return new ResultInfo(pkind, newPt, newContext, checkMode);
 533         }
 534 
 535         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 536             return new ResultInfo(pkind, newPt, newContext, newMode);
 537         }
 538 
 539         protected ResultInfo dup(CheckMode newMode) {
 540             return new ResultInfo(pkind, pt, checkContext, newMode);
 541         }
 542 
 543         @Override
 544         public String toString() {
 545             if (pt != null) {
 546                 return pt.toString();
 547             } else {
 548                 return "";
 549             }
 550         }
 551     }
 552 
 553     class MethodAttrInfo extends ResultInfo {
 554         public MethodAttrInfo() {
 555             this(chk.basicHandler);
 556         }
 557 
 558         public MethodAttrInfo(CheckContext checkContext) {
 559             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 560         }
 561 
 562         @Override
 563         protected boolean needsArgumentAttr(JCTree tree) {
 564             return true;
 565         }
 566 
 567         protected ResultInfo dup(Type newPt) {
 568             throw new IllegalStateException();
 569         }
 570 
 571         protected ResultInfo dup(CheckContext newContext) {
 572             return new MethodAttrInfo(newContext);
 573         }
 574 
 575         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 576             throw new IllegalStateException();
 577         }
 578 
 579         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 580             throw new IllegalStateException();
 581         }
 582 
 583         protected ResultInfo dup(CheckMode newMode) {
 584             throw new IllegalStateException();
 585         }
 586     }
 587 
 588     class RecoveryInfo extends ResultInfo {
 589 
 590         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 591             this(deferredAttrContext, Type.recoveryType);
 592         }
 593 
 594         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 595             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 596                 @Override
 597                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 598                     return deferredAttrContext;
 599                 }
 600                 @Override
 601                 public boolean compatible(Type found, Type req, Warner warn) {
 602                     return true;
 603                 }
 604                 @Override
 605                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 606                     boolean needsReport = pt == Type.recoveryType ||
 607                             (details.getDiagnosticPosition() != null &&
 608                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 609                     if (needsReport) {
 610                         chk.basicHandler.report(pos, details);
 611                     }
 612                 }
 613             });
 614         }
 615     }
 616 
 617     final ResultInfo statInfo;
 618     final ResultInfo varAssignmentInfo;
 619     final ResultInfo methodAttrInfo;
 620     final ResultInfo unknownExprInfo;
 621     final ResultInfo unknownTypeInfo;
 622     final ResultInfo unknownTypeExprInfo;
 623     final ResultInfo recoveryInfo;
 624     final MethodType initBlockType;
 625 
 626     Type pt() {
 627         return resultInfo.pt;
 628     }
 629 
 630     KindSelector pkind() {
 631         return resultInfo.pkind;
 632     }
 633 
 634 /* ************************************************************************
 635  * Visitor methods
 636  *************************************************************************/
 637 
 638     /** Visitor argument: the current environment.
 639      */
 640     Env<AttrContext> env;
 641 
 642     /** Visitor argument: the currently expected attribution result.
 643      */
 644     ResultInfo resultInfo;
 645 
 646     /** Visitor result: the computed type.
 647      */
 648     Type result;
 649 
 650     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 651 
 652     /** Visitor method: attribute a tree, catching any completion failure
 653      *  exceptions. Return the tree's type.
 654      *
 655      *  @param tree    The tree to be visited.
 656      *  @param env     The environment visitor argument.
 657      *  @param resultInfo   The result info visitor argument.
 658      */
 659     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 660         Env<AttrContext> prevEnv = this.env;
 661         ResultInfo prevResult = this.resultInfo;
 662         try {
 663             this.env = env;
 664             this.resultInfo = resultInfo;
 665             if (resultInfo.needsArgumentAttr(tree)) {
 666                 result = argumentAttr.attribArg(tree, env);
 667             } else {
 668                 tree.accept(this);
 669             }
 670             matchBindings = matchBindingsComputer.finishBindings(tree,
 671                                                                  matchBindings);
 672             if (tree == breakTree &&
 673                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 674                 breakTreeFound(copyEnv(env));
 675             }
 676             return result;
 677         } catch (CompletionFailure ex) {
 678             tree.type = syms.errType;
 679             return chk.completionError(tree.pos(), ex);
 680         } finally {
 681             this.env = prevEnv;
 682             this.resultInfo = prevResult;
 683         }
 684     }
 685 
 686     protected void breakTreeFound(Env<AttrContext> env) {
 687         throw new BreakAttr(env);
 688     }
 689 
 690     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 691         Env<AttrContext> newEnv =
 692                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 693         if (newEnv.outer != null) {
 694             newEnv.outer = copyEnv(newEnv.outer);
 695         }
 696         return newEnv;
 697     }
 698 
 699     WriteableScope copyScope(WriteableScope sc) {
 700         WriteableScope newScope = WriteableScope.create(sc.owner);
 701         List<Symbol> elemsList = List.nil();
 702         for (Symbol sym : sc.getSymbols()) {
 703             elemsList = elemsList.prepend(sym);
 704         }
 705         for (Symbol s : elemsList) {
 706             newScope.enter(s);
 707         }
 708         return newScope;
 709     }
 710 
 711     /** Derived visitor method: attribute an expression tree.
 712      */
 713     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 714         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 715     }
 716 
 717     /** Derived visitor method: attribute an expression tree with
 718      *  no constraints on the computed type.
 719      */
 720     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 721         return attribTree(tree, env, unknownExprInfo);
 722     }
 723 
 724     /** Derived visitor method: attribute a type tree.
 725      */
 726     public Type attribType(JCTree tree, Env<AttrContext> env) {
 727         Type result = attribType(tree, env, Type.noType);
 728         return result;
 729     }
 730 
 731     /** Derived visitor method: attribute a type tree.
 732      */
 733     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 734         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 735         return result;
 736     }
 737 
 738     /** Derived visitor method: attribute a statement or definition tree.
 739      */
 740     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 741         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 742         Type result = attribTree(tree, env, statInfo);
 743         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 744         attrRecover.doRecovery();
 745         return result;
 746     }
 747 
 748     /** Attribute a list of expressions, returning a list of types.
 749      */
 750     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 751         ListBuffer<Type> ts = new ListBuffer<>();
 752         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 753             ts.append(attribExpr(l.head, env, pt));
 754         return ts.toList();
 755     }
 756 
 757     /** Attribute a list of statements, returning nothing.
 758      */
 759     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 760         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 761             attribStat(l.head, env);
 762     }
 763 
 764     /** Attribute the arguments in a method call, returning the method kind.
 765      */
 766     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 767         KindSelector kind = initialKind;
 768         for (JCExpression arg : trees) {
 769             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 770             if (argtype.hasTag(DEFERRED)) {
 771                 kind = KindSelector.of(KindSelector.POLY, kind);
 772             }
 773             argtypes.append(argtype);
 774         }
 775         return kind;
 776     }
 777 
 778     /** Attribute a type argument list, returning a list of types.
 779      *  Caller is responsible for calling checkRefTypes.
 780      */
 781     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 782         ListBuffer<Type> argtypes = new ListBuffer<>();
 783         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 784             argtypes.append(attribType(l.head, env));
 785         return argtypes.toList();
 786     }
 787 
 788     /** Attribute a type argument list, returning a list of types.
 789      *  Check that all the types are references.
 790      */
 791     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 792         List<Type> types = attribAnyTypes(trees, env);
 793         return chk.checkRefTypes(trees, types);
 794     }
 795 
 796     /**
 797      * Attribute type variables (of generic classes or methods).
 798      * Compound types are attributed later in attribBounds.
 799      * @param typarams the type variables to enter
 800      * @param env      the current environment
 801      */
 802     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 803         for (JCTypeParameter tvar : typarams) {
 804             TypeVar a = (TypeVar)tvar.type;
 805             a.tsym.flags_field |= UNATTRIBUTED;
 806             a.setUpperBound(Type.noType);
 807             if (!tvar.bounds.isEmpty()) {
 808                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 809                 for (JCExpression bound : tvar.bounds.tail)
 810                     bounds = bounds.prepend(attribType(bound, env));
 811                 types.setBounds(a, bounds.reverse());
 812             } else {
 813                 // if no bounds are given, assume a single bound of
 814                 // java.lang.Object.
 815                 types.setBounds(a, List.of(syms.objectType));
 816             }
 817             a.tsym.flags_field &= ~UNATTRIBUTED;
 818         }
 819         if (checkCyclic) {
 820             for (JCTypeParameter tvar : typarams) {
 821                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 822             }
 823         }
 824     }
 825 
 826     /**
 827      * Attribute the type references in a list of annotations.
 828      */
 829     void attribAnnotationTypes(List<JCAnnotation> annotations,
 830                                Env<AttrContext> env) {
 831         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 832             JCAnnotation a = al.head;
 833             attribType(a.annotationType, env);
 834         }
 835     }
 836 
 837     /**
 838      * Attribute a "lazy constant value".
 839      *  @param env         The env for the const value
 840      *  @param variable    The initializer for the const value
 841      *  @param type        The expected type, or null
 842      *  @see VarSymbol#setLazyConstValue
 843      */
 844     public Object attribLazyConstantValue(Env<AttrContext> env,
 845                                       Env<AttrContext> enclosingEnv,
 846                                       JCVariableDecl variable,
 847                                       Type type) {
 848         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 849         try {
 850             doQueueScanTreeAndTypeAnnotateForVarInit(variable, enclosingEnv);
 851             Type itype = attribExpr(variable.init, env, type);
 852             if (variable.isImplicitlyTyped()) {
 853                 //fixup local variable type
 854                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 855             }
 856             if (itype.constValue() != null) {
 857                 return coerce(itype, type).constValue();
 858             } else {
 859                 return null;
 860             }
 861         } finally {
 862             log.useSource(prevSource);
 863         }
 864     }
 865 
 866     /** Attribute type reference in an `extends', `implements', or 'permits' clause.
 867      *  Supertypes of anonymous inner classes are usually already attributed.
 868      *
 869      *  @param tree              The tree making up the type reference.
 870      *  @param env               The environment current at the reference.
 871      *  @param classExpected     true if only a class is expected here.
 872      *  @param interfaceExpected true if only an interface is expected here.
 873      */
 874     Type attribBase(JCTree tree,
 875                     Env<AttrContext> env,
 876                     boolean classExpected,
 877                     boolean interfaceExpected,
 878                     boolean checkExtensible) {
 879         Type t = tree.type != null ?
 880             tree.type :
 881             attribType(tree, env);
 882         try {
 883             return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 884         } catch (CompletionFailure ex) {
 885             chk.completionError(tree.pos(), ex);
 886             return t;
 887         }
 888     }
 889     Type checkBase(Type t,
 890                    JCTree tree,
 891                    Env<AttrContext> env,
 892                    boolean classExpected,
 893                    boolean interfaceExpected,
 894                    boolean checkExtensible) {
 895         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 896                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 897         if (t.tsym.isAnonymous()) {
 898             log.error(pos, Errors.CantInheritFromAnon);
 899             return types.createErrorType(t);
 900         }
 901         if (t.isErroneous())
 902             return t;
 903         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 904             // check that type variable is already visible
 905             if (t.getUpperBound() == null) {
 906                 log.error(pos, Errors.IllegalForwardRef);
 907                 return types.createErrorType(t);
 908             }
 909         } else {
 910             t = chk.checkClassType(pos, t, checkExtensible);
 911         }
 912         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 913             log.error(pos, Errors.IntfExpectedHere);
 914             // return errType is necessary since otherwise there might
 915             // be undetected cycles which cause attribution to loop
 916             return types.createErrorType(t);
 917         } else if (checkExtensible &&
 918                    classExpected &&
 919                    (t.tsym.flags() & INTERFACE) != 0) {
 920             log.error(pos, Errors.NoIntfExpectedHere);
 921             return types.createErrorType(t);
 922         }
 923         if (checkExtensible &&
 924             ((t.tsym.flags() & FINAL) != 0)) {
 925             log.error(pos,
 926                       Errors.CantInheritFromFinal(t.tsym));
 927         }
 928         chk.checkNonCyclic(pos, t);
 929         return t;
 930     }
 931 
 932     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 933         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 934         id.type = env.info.scope.owner.enclClass().type;
 935         id.sym = env.info.scope.owner.enclClass();
 936         return id.type;
 937     }
 938 
 939     public void visitClassDef(JCClassDecl tree) {
 940         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 941                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 942                         argumentAttr.withLocalCacheContext() : null);
 943         boolean ctorProloguePrev = env.info.ctorPrologue;
 944         try {
 945             // Local and anonymous classes have not been entered yet, so we need to
 946             // do it now.
 947             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 948                 enter.classEnter(tree, env);
 949             } else {
 950                 // If this class declaration is part of a class level annotation,
 951                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 952                 // order to simplify later steps and allow for sensible error
 953                 // messages.
 954                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 955                     enter.classEnter(tree, env);
 956             }
 957 
 958             ClassSymbol c = tree.sym;
 959             if (c == null) {
 960                 // exit in case something drastic went wrong during enter.
 961                 result = null;
 962             } else {
 963                 // make sure class has been completed:
 964                 c.complete();
 965 
 966                 // If a class declaration appears in a constructor prologue,
 967                 // that means it's either a local class or an anonymous class.
 968                 // Either way, there is no immediately enclosing instance.
 969                 if (ctorProloguePrev) {
 970                     c.flags_field |= NOOUTERTHIS;
 971                 }
 972                 attribClass(tree.pos(), c);
 973                 result = tree.type = c.type;
 974             }
 975         } finally {
 976             localCacheContext.ifPresent(LocalCacheContext::leave);
 977             env.info.ctorPrologue = ctorProloguePrev;
 978         }
 979     }
 980 
 981     public void visitMethodDef(JCMethodDecl tree) {
 982         MethodSymbol m = tree.sym;
 983         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
 984 
 985         Lint lint = env.info.lint.augment(m);
 986         Lint prevLint = chk.setLint(lint);
 987         boolean ctorProloguePrev = env.info.ctorPrologue;
 988         Assert.check(!env.info.ctorPrologue);
 989         MethodSymbol prevMethod = chk.setMethod(m);
 990         try {
 991             chk.checkDeprecatedAnnotation(tree.pos(), m);
 992 
 993 
 994             // Create a new environment with local scope
 995             // for attributing the method.
 996             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
 997             localEnv.info.lint = lint;
 998 
 999             attribStats(tree.typarams, localEnv);
1000 
1001             // If we override any other methods, check that we do so properly.
1002             // JLS ???
1003             if (m.isStatic()) {
1004                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1005             } else {
1006                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1007             }
1008             chk.checkOverride(env, tree, m);
1009 
1010             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1011                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1012             }
1013 
1014             // Enter all type parameters into the local method scope.
1015             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1016                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1017 
1018             ClassSymbol owner = env.enclClass.sym;
1019             if ((owner.flags() & ANNOTATION) != 0 &&
1020                     (tree.params.nonEmpty() ||
1021                     tree.recvparam != null))
1022                 log.error(tree.params.nonEmpty() ?
1023                         tree.params.head.pos() :
1024                         tree.recvparam.pos(),
1025                         Errors.IntfAnnotationMembersCantHaveParams);
1026 
1027             // Attribute all value parameters.
1028             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1029                 attribStat(l.head, localEnv);
1030             }
1031 
1032             chk.checkVarargsMethodDecl(localEnv, tree);
1033 
1034             // Check that type parameters are well-formed.
1035             chk.validate(tree.typarams, localEnv);
1036 
1037             // Check that result type is well-formed.
1038             if (tree.restype != null && !tree.restype.type.hasTag(VOID)) {
1039                 chk.validate(tree.restype, localEnv);
1040             }
1041             chk.checkRequiresIdentity(tree, env.info.lint);
1042 
1043             // Check that receiver type is well-formed.
1044             if (tree.recvparam != null) {
1045                 // Use a new environment to check the receiver parameter.
1046                 // Otherwise I get "might not have been initialized" errors.
1047                 // Is there a better way?
1048                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1049                 attribType(tree.recvparam, newEnv);
1050                 chk.validate(tree.recvparam, newEnv);
1051             }
1052 
1053             // Is this method a constructor?
1054             boolean isConstructor = TreeInfo.isConstructor(tree);
1055 
1056             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1057                 // lets find if this method is an accessor
1058                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1059                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1060                 if (recordComponent.isPresent()) {
1061                     // the method is a user defined accessor lets check that everything is fine
1062                     if (!tree.sym.isPublic()) {
1063                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1064                     }
1065                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1066                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1067                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1068                     }
1069                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1070                         log.error(tree,
1071                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1072                     }
1073                     if (!tree.typarams.isEmpty()) {
1074                         log.error(tree,
1075                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1076                     }
1077                     if (tree.sym.isStatic()) {
1078                         log.error(tree,
1079                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1080                     }
1081                 }
1082 
1083                 if (isConstructor) {
1084                     // if this a constructor other than the canonical one
1085                     if ((tree.sym.flags_field & RECORD) == 0) {
1086                         if (!TreeInfo.hasConstructorCall(tree, names._this)) {
1087                             log.error(tree, Errors.NonCanonicalConstructorInvokeAnotherConstructor(env.enclClass.sym));
1088                         }
1089                     } else {
1090                         // but if it is the canonical:
1091 
1092                         /* if user generated, then it shouldn't:
1093                          *     - have an accessibility stricter than that of the record type
1094                          *     - explicitly invoke any other constructor
1095                          */
1096                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1097                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1098                                 log.error(tree,
1099                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1100                                             Errors.InvalidCanonicalConstructorInRecord(
1101                                                 Fragments.Canonical,
1102                                                 env.enclClass.sym.name,
1103                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1104                                             ) :
1105                                             Errors.InvalidCanonicalConstructorInRecord(
1106                                                     Fragments.Canonical,
1107                                                     env.enclClass.sym.name,
1108                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1109                                             )
1110                                 );
1111                             }
1112 
1113                             if ((!allowValueClasses || TreeInfo.isCompactConstructor(tree)) &&
1114                                     TreeInfo.hasAnyConstructorCall(tree)) {
1115                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1116                                         Fragments.Canonical, env.enclClass.sym.name,
1117                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1118                             }
1119                         }
1120 
1121                         // also we want to check that no type variables have been defined
1122                         if (!tree.typarams.isEmpty()) {
1123                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1124                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1125                         }
1126 
1127                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1128                          * record components
1129                          */
1130                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1131                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1132                         for (JCVariableDecl param: tree.params) {
1133                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1134                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1135                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1136                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1137                                         Fragments.Canonical, env.enclClass.sym.name,
1138                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1139                             }
1140                             recordComponents = recordComponents.tail;
1141                             recordFieldTypes = recordFieldTypes.tail;
1142                         }
1143                     }
1144                 }
1145             }
1146 
1147             // annotation method checks
1148             if ((owner.flags() & ANNOTATION) != 0) {
1149                 // annotation method cannot have throws clause
1150                 if (tree.thrown.nonEmpty()) {
1151                     log.error(tree.thrown.head.pos(),
1152                               Errors.ThrowsNotAllowedInIntfAnnotation);
1153                 }
1154                 // annotation method cannot declare type-parameters
1155                 if (tree.typarams.nonEmpty()) {
1156                     log.error(tree.typarams.head.pos(),
1157                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1158                 }
1159                 // validate annotation method's return type (could be an annotation type)
1160                 chk.validateAnnotationType(tree.restype);
1161                 // ensure that annotation method does not clash with members of Object/Annotation
1162                 chk.validateAnnotationMethod(tree.pos(), m);
1163             }
1164 
1165             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1166                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1167 
1168             if (tree.body == null) {
1169                 // Empty bodies are only allowed for
1170                 // abstract, native, or interface methods, or for methods
1171                 // in a retrofit signature class.
1172                 if (tree.defaultValue != null) {
1173                     if ((owner.flags() & ANNOTATION) == 0)
1174                         log.error(tree.pos(),
1175                                   Errors.DefaultAllowedInIntfAnnotationMember);
1176                 }
1177                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1178                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract(tree.sym, owner));
1179             } else {
1180                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1181                     if ((owner.flags() & INTERFACE) != 0) {
1182                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1183                     } else {
1184                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1185                     }
1186                 } else if ((tree.mods.flags & NATIVE) != 0) {
1187                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1188                 }
1189                 // Add an implicit super() call unless an explicit call to
1190                 // super(...) or this(...) is given
1191                 // or we are compiling class java.lang.Object.
1192                 boolean addedSuperInIdentityClass = false;
1193                 if (isConstructor && owner.type != syms.objectType) {
1194                     if (!TreeInfo.hasAnyConstructorCall(tree)) {
1195                         JCStatement supCall = make.at(tree.body.pos).Exec(make.Apply(List.nil(),
1196                                 make.Ident(names._super), make.Idents(List.nil())));
1197                         if (allowValueClasses && (owner.isValueClass() || owner.hasStrict() || ((owner.flags_field & RECORD) != 0))) {
1198                             tree.body.stats = tree.body.stats.append(supCall);
1199                         } else {
1200                             tree.body.stats = tree.body.stats.prepend(supCall);
1201                             addedSuperInIdentityClass = true;
1202                         }
1203                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1204                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1205                             TreeInfo.hasConstructorCall(tree, names._super)) {
1206                         // enum constructors are not allowed to call super
1207                         // directly, so make sure there aren't any super calls
1208                         // in enum constructors, except in the compiler
1209                         // generated one.
1210                         log.error(tree.body.stats.head.pos(),
1211                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1212                     }
1213                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1214                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1215                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1216                         if (!initParamNames.equals(recordComponentNames)) {
1217                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1218                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1219                         }
1220                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1221                             log.error(tree,
1222                                     Errors.InvalidCanonicalConstructorInRecord(
1223                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1224                                             env.enclClass.sym.name,
1225                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1226                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1227                         }
1228                     }
1229                 }
1230 
1231                 // Attribute all type annotations in the body
1232                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m);
1233                 annotate.flush();
1234 
1235                 // Start of constructor prologue (if not in java.lang.Object constructor)
1236                 localEnv.info.ctorPrologue = isConstructor && owner.type != syms.objectType;
1237 
1238                 // Attribute method body.
1239                 attribStat(tree.body, localEnv);
1240                 if (localEnv.info.ctorPrologue) {
1241                     boolean thisInvocation = false;
1242                     ListBuffer<JCTree> prologueCode = new ListBuffer<>();
1243                     for (JCTree stat : tree.body.stats) {
1244                         prologueCode.add(stat);
1245                         /* gather all the stats in the body until a `super` or `this` constructor invocation is found,
1246                          * including the constructor invocation, that way we don't need to worry in the visitor below if
1247                          * if we are dealing or not with prologue code
1248                          */
1249                         if (stat instanceof JCExpressionStatement expStmt &&
1250                                 expStmt.expr instanceof JCMethodInvocation mi &&
1251                                 TreeInfo.isConstructorCall(mi)) {
1252                             thisInvocation = TreeInfo.name(mi.meth) == names._this;
1253                             if (!addedSuperInIdentityClass || !allowValueClasses) {
1254                                 break;
1255                             }
1256                         }
1257                     }
1258                     if (!prologueCode.isEmpty()) {
1259                         CtorPrologueVisitor ctorPrologueVisitor = new CtorPrologueVisitor(localEnv,
1260                                 addedSuperInIdentityClass && allowValueClasses ?
1261                                         PrologueVisitorMode.WARNINGS_ONLY :
1262                                         thisInvocation ?
1263                                                 PrologueVisitorMode.THIS_CONSTRUCTOR :
1264                                                 PrologueVisitorMode.SUPER_CONSTRUCTOR,
1265                                 false);
1266                         ctorPrologueVisitor.scan(prologueCode.toList());
1267                     }
1268                 }
1269             }
1270 
1271             localEnv.info.scope.leave();
1272             result = tree.type = m.type;
1273         } finally {
1274             chk.setLint(prevLint);
1275             chk.setMethod(prevMethod);
1276             env.info.ctorPrologue = ctorProloguePrev;
1277         }
1278     }
1279 
1280     enum PrologueVisitorMode {
1281         WARNINGS_ONLY,
1282         SUPER_CONSTRUCTOR,
1283         THIS_CONSTRUCTOR
1284     }
1285 
1286     class CtorPrologueVisitor extends TreeScanner {
1287         Env<AttrContext> localEnv;
1288         PrologueVisitorMode mode;
1289         boolean isInitializer;
1290 
1291         CtorPrologueVisitor(Env<AttrContext> localEnv, PrologueVisitorMode mode, boolean isInitializer) {
1292             this.localEnv = localEnv;
1293             currentClassSym = localEnv.enclClass.sym;
1294             this.mode = mode;
1295             this.isInitializer = isInitializer;
1296         }
1297 
1298         boolean insideLambdaOrClassDef = false;
1299 
1300         @Override
1301         public void visitLambda(JCLambda lambda) {
1302             boolean previousInsideLambdaOrClassDef = insideLambdaOrClassDef;
1303             try {
1304                 insideLambdaOrClassDef = true;
1305                 super.visitLambda(lambda);
1306             } finally {
1307                 insideLambdaOrClassDef = previousInsideLambdaOrClassDef;
1308             }
1309         }
1310 
1311         ClassSymbol currentClassSym;
1312 
1313         @Override
1314         public void visitClassDef(JCClassDecl classDecl) {
1315             boolean previousInsideLambdaOrClassDef = insideLambdaOrClassDef;
1316             ClassSymbol previousClassSym = currentClassSym;
1317             try {
1318                 insideLambdaOrClassDef = true;
1319                 currentClassSym = classDecl.sym;
1320                 super.visitClassDef(classDecl);
1321             } finally {
1322                 insideLambdaOrClassDef = previousInsideLambdaOrClassDef;
1323                 currentClassSym = previousClassSym;
1324             }
1325         }
1326 
1327         private void reportPrologueError(JCTree tree, Symbol sym) {
1328             reportPrologueError(tree, sym, false);
1329         }
1330 
1331         private void reportPrologueError(JCTree tree, Symbol sym, boolean hasInit) {
1332             preview.checkSourceLevel(tree, Feature.FLEXIBLE_CONSTRUCTORS);
1333             if (mode != PrologueVisitorMode.WARNINGS_ONLY) {
1334                 if (hasInit) {
1335                     log.error(tree, Errors.CantAssignInitializedBeforeCtorCalled(sym));
1336                 } else {
1337                     log.error(tree, Errors.CantRefBeforeCtorCalled(sym));
1338                 }
1339             } else if (allowValueClasses) {
1340                 // issue lint warning
1341                 log.warning(tree, LintWarnings.WouldNotBeAllowedInPrologue(sym));
1342             }
1343         }
1344 
1345         @Override
1346         public void visitApply(JCMethodInvocation tree) {
1347             super.visitApply(tree);
1348             Name name = TreeInfo.name(tree.meth);
1349             boolean isConstructorCall = name == names._this || name == names._super;
1350             Symbol msym = TreeInfo.symbolFor(tree.meth);
1351             // is this an instance method call or an illegal constructor invocation like: `this.super()`?
1352             if (msym != null && // for erroneous invocations msym can be null, ignore those
1353                 (!isConstructorCall ||
1354                 isConstructorCall && tree.meth.hasTag(SELECT))) {
1355                 if (isEarlyReference(localEnv, tree.meth, msym))
1356                     reportPrologueError(tree.meth, msym);
1357             }
1358         }
1359 
1360         @Override
1361         public void visitIdent(JCIdent tree) {
1362             analyzeSymbol(tree);
1363         }
1364 
1365         boolean isIndexed = false;
1366 
1367         @Override
1368         public void visitIndexed(JCArrayAccess tree) {
1369             boolean previousIsIndexed = isIndexed;
1370             try {
1371                 isIndexed = true;
1372                 scan(tree.indexed);
1373             } finally {
1374                 isIndexed = previousIsIndexed;
1375             }
1376             scan(tree.index);
1377             if (mode == PrologueVisitorMode.SUPER_CONSTRUCTOR && isInstanceField(tree.indexed)) {
1378                 localProxyVarsGen.addFieldReadInPrologue(localEnv.enclMethod, TreeInfo.symbolFor(tree.indexed));
1379             }
1380         }
1381 
1382         @Override
1383         public void visitSelect(JCFieldAccess tree) {
1384             SelectScanner ss = new SelectScanner();
1385             ss.scan(tree);
1386             if (ss.scanLater == null) {
1387                 Symbol sym = TreeInfo.symbolFor(tree);
1388                 // if this is a field access
1389                 if (sym.kind == VAR && sym.owner.kind == TYP) {
1390                     // Type.super.field or super.field expressions are forbidden in early construction contexts
1391                     for (JCTree subtree : ss.selectorTrees) {
1392                         if (TreeInfo.isSuperOrSelectorDotSuper(subtree)) {
1393                             reportPrologueError(tree, sym);
1394                             return;
1395                         }
1396                     }
1397                 }
1398                 analyzeSymbol(tree);
1399             } else {
1400                 boolean prevLhs = isInLHS;
1401                 try {
1402                     isInLHS = false;
1403                     scan(ss.scanLater);
1404                 } finally {
1405                     isInLHS = prevLhs;
1406                 }
1407             }
1408             if (mode == PrologueVisitorMode.SUPER_CONSTRUCTOR) {
1409                 for (JCTree subtree : ss.selectorTrees) {
1410                     if (isInstanceField(subtree)) {
1411                         // we need to add a proxy for this one
1412                         localProxyVarsGen.addFieldReadInPrologue(localEnv.enclMethod, TreeInfo.symbolFor(subtree));
1413                     }
1414                 }
1415             }
1416         }
1417 
1418         boolean isInstanceField(JCTree tree) {
1419             Symbol sym = TreeInfo.symbolFor(tree);
1420             return (sym != null &&
1421                     !sym.isStatic() &&
1422                     sym.kind == VAR &&
1423                     sym.owner.kind == TYP &&
1424                     sym.name != names._this &&
1425                     sym.name != names._super &&
1426                     isEarlyReference(localEnv, tree, sym));
1427         }
1428 
1429         @Override
1430         public void visitNewClass(JCNewClass tree) {
1431             super.visitNewClass(tree);
1432             checkNewClassAndMethRefs(tree, tree.type);
1433         }
1434 
1435         @Override
1436         public void visitReference(JCMemberReference tree) {
1437             super.visitReference(tree);
1438             if (tree.getMode() == JCMemberReference.ReferenceMode.NEW) {
1439                 checkNewClassAndMethRefs(tree, tree.expr.type);
1440             }
1441         }
1442 
1443         void checkNewClassAndMethRefs(JCTree tree, Type t) {
1444             if (t.tsym.isEnclosedBy(localEnv.enclClass.sym) &&
1445                     !t.tsym.isStatic() &&
1446                     !t.tsym.isDirectlyOrIndirectlyLocal()) {
1447                 reportPrologueError(tree, t.getEnclosingType().tsym);
1448             }
1449         }
1450 
1451         /* if a symbol is in the LHS of an assignment expression we won't consider it as a candidate
1452          * for a proxy local variable later on
1453          */
1454         boolean isInLHS = false;
1455 
1456         @Override
1457         public void visitAssign(JCAssign tree) {
1458             boolean previousIsInLHS = isInLHS;
1459             try {
1460                 isInLHS = true;
1461                 scan(tree.lhs);
1462             } finally {
1463                 isInLHS = previousIsInLHS;
1464             }
1465             scan(tree.rhs);
1466         }
1467 
1468         @Override
1469         public void visitMethodDef(JCMethodDecl tree) {
1470             // ignore any declarative part, mainly to avoid scanning receiver parameters
1471             scan(tree.body);
1472         }
1473 
1474         void analyzeSymbol(JCTree tree) {
1475             Symbol sym = TreeInfo.symbolFor(tree);
1476             // make sure that there is a symbol and it is not static
1477             if (sym == null || sym.isStatic()) {
1478                 return;
1479             }
1480             if (isInLHS && !insideLambdaOrClassDef) {
1481                 // Check instance field assignments that appear in constructor prologues
1482                 if (isEarlyReference(localEnv, tree, sym)) {
1483                     // Field may not be inherited from a superclass
1484                     if (sym.owner != localEnv.enclClass.sym) {
1485                         reportPrologueError(tree, sym);
1486                         return;
1487                     }
1488                     // Field may not have an initializer
1489                     if ((sym.flags() & HASINIT) != 0) {
1490                         if (!localEnv.enclClass.sym.isValueClass() || !sym.type.hasTag(ARRAY) || !isIndexed) {
1491                             reportPrologueError(tree, sym, true);
1492                         }
1493                         return;
1494                     }
1495                     // cant reference an instance field before a this constructor
1496                     if (allowValueClasses && mode == PrologueVisitorMode.THIS_CONSTRUCTOR) {
1497                         reportPrologueError(tree, sym);
1498                         return;
1499                     }
1500                 }
1501                 return;
1502             }
1503             tree = TreeInfo.skipParens(tree);
1504             if (sym.kind == VAR && sym.owner.kind == TYP) {
1505                 if (sym.name == names._this || sym.name == names._super) {
1506                     // are we seeing something like `this` or `CurrentClass.this` or `SuperClass.super::foo`?
1507                     if (TreeInfo.isExplicitThisReference(
1508                             types,
1509                             (ClassType)localEnv.enclClass.sym.type,
1510                             tree)) {
1511                         reportPrologueError(tree, sym);
1512                     }
1513                 } else if (sym.kind == VAR && sym.owner.kind == TYP) { // now fields only
1514                     if (sym.owner != localEnv.enclClass.sym) {
1515                         if (localEnv.enclClass.sym.isSubClass(sym.owner, types) &&
1516                                 sym.isInheritedIn(localEnv.enclClass.sym, types)) {
1517                             /* if we are dealing with a field that doesn't belong to the current class, but the
1518                              * field is inherited, this is an error. Unless, the super class is also an outer
1519                              * class and the field's qualifier refers to the outer class
1520                              */
1521                             if (tree.hasTag(IDENT) ||
1522                                 TreeInfo.isExplicitThisReference(
1523                                         types,
1524                                         (ClassType)localEnv.enclClass.sym.type,
1525                                         ((JCFieldAccess)tree).selected)) {
1526                                 reportPrologueError(tree, sym);
1527                             }
1528                         }
1529                     } else if (isEarlyReference(localEnv, tree, sym)) {
1530                         /* now this is a `proper` instance field of the current class
1531                          * references to fields of identity classes which happen to have initializers are
1532                          * not allowed in the prologue.
1533                          * But it is OK for a field with initializer to refer to another field with initializer,
1534                          * so no warning or error if we are analyzing a field initializer.
1535                          */
1536                         if (insideLambdaOrClassDef ||
1537                             (!localEnv.enclClass.sym.isValueClass() &&
1538                              (sym.flags_field & HASINIT) != 0 &&
1539                              !isInitializer))
1540                             reportPrologueError(tree, sym);
1541                         // we will need to generate a proxy for this field later on
1542                         if (!isInLHS) {
1543                             if (!allowValueClasses) {
1544                                 reportPrologueError(tree, sym);
1545                             } else {
1546                                 if (mode == PrologueVisitorMode.THIS_CONSTRUCTOR) {
1547                                     reportPrologueError(tree, sym);
1548                                 } else if (mode == PrologueVisitorMode.SUPER_CONSTRUCTOR) {
1549                                     localProxyVarsGen.addFieldReadInPrologue(localEnv.enclMethod, sym);
1550                                 }
1551                                 /* we do nothing in warnings only mode, as in that mode we are simulating what
1552                                  * the compiler would do in case the constructor code would be in the prologue
1553                                  * phase
1554                                  */
1555                             }
1556                         }
1557                     }
1558                 }
1559             }
1560         }
1561 
1562         /**
1563          * Determine if the symbol appearance constitutes an early reference to the current class.
1564          *
1565          * <p>
1566          * This means the symbol is an instance field, or method, of the current class and it appears
1567          * in an early initialization context of it (i.e., one of its constructor prologues).
1568          *
1569          * @param env    The current environment
1570          * @param tree   the AST referencing the variable
1571          * @param sym    The symbol
1572          */
1573         private boolean isEarlyReference(Env<AttrContext> env, JCTree tree, Symbol sym) {
1574             if ((sym.flags() & STATIC) == 0 &&
1575                     (sym.kind == VAR || sym.kind == MTH) &&
1576                     sym.isMemberOf(env.enclClass.sym, types)) {
1577                 // Allow "Foo.this.x" when "Foo" is (also) an outer class, as this refers to the outer instance
1578                 if (tree instanceof JCFieldAccess fa) {
1579                     return TreeInfo.isExplicitThisReference(types, (ClassType)env.enclClass.type, fa.selected);
1580                 } else if (currentClassSym != env.enclClass.sym) {
1581                     /* so we are inside a class, CI, in the prologue of an outer class, CO, and the symbol being
1582                      * analyzed has no qualifier. So if the symbol is a member of CI the reference is allowed,
1583                      * otherwise it is not.
1584                      * It could be that the reference to CI's member happens inside CI's own prologue, but that
1585                      * will be checked separately, when CI's prologue is analyzed.
1586                      */
1587                     return !sym.isMemberOf(currentClassSym, types);
1588                 }
1589                 return true;
1590             }
1591             return false;
1592         }
1593 
1594         /* scanner for a select expression, anything that is not a select or identifier
1595          * will be stored for further analysis
1596          */
1597         class SelectScanner extends DeferredAttr.FilterScanner {
1598             JCTree scanLater;
1599             java.util.List<JCTree> selectorTrees = new ArrayList<>();
1600 
1601             SelectScanner() {
1602                 super(Set.of(IDENT, SELECT, PARENS));
1603             }
1604 
1605             @Override
1606             public void visitSelect(JCFieldAccess tree) {
1607                 super.visitSelect(tree);
1608                 selectorTrees.add(tree.selected);
1609             }
1610 
1611             @Override
1612             void skip(JCTree tree) {
1613                 scanLater = tree;
1614             }
1615         }
1616     }
1617 
1618     public void visitVarDef(JCVariableDecl tree) {
1619         // Local variables have not been entered yet, so we need to do it now:
1620         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1621             if (tree.sym != null) {
1622                 // parameters have already been entered
1623                 env.info.scope.enter(tree.sym);
1624             } else {
1625                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
1626                     if (tree.init == null) {
1627                         //cannot use 'var' without initializer
1628                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1629                         tree.vartype = make.at(tree.pos()).Erroneous();
1630                     } else {
1631                         Fragment msg = canInferLocalVarType(tree);
1632                         if (msg != null) {
1633                             //cannot use 'var' with initializer which require an explicit target
1634                             //(e.g. lambda, method reference, array initializer).
1635                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1636                             tree.vartype = make.at(tree.pos()).Erroneous();
1637                         }
1638                     }
1639                 }
1640                 try {
1641                     annotate.blockAnnotations();
1642                     memberEnter.memberEnter(tree, env);
1643                 } finally {
1644                     annotate.unblockAnnotations();
1645                 }
1646             }
1647         } else {
1648             doQueueScanTreeAndTypeAnnotateForVarInit(tree, env);
1649         }
1650 
1651         VarSymbol v = tree.sym;
1652         Lint lint = env.info.lint.augment(v);
1653         Lint prevLint = chk.setLint(lint);
1654 
1655         // Check that the variable's declared type is well-formed.
1656         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1657                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1658                 (tree.sym.flags() & PARAMETER) != 0;
1659         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1660 
1661         try {
1662             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1663             chk.checkDeprecatedAnnotation(tree.pos(), v);
1664 
1665             if (tree.init != null) {
1666                 Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
1667                 if ((v.flags_field & FINAL) == 0 ||
1668                     !memberEnter.needsLazyConstValue(tree.init)) {
1669                     // Not a compile-time constant
1670                     // Attribute initializer in a new environment
1671                     // with the declared variable as owner.
1672                     // Check that initializer conforms to variable's declared type.

1673                     initEnv.info.lint = lint;
1674                     // In order to catch self-references, we set the variable's
1675                     // declaration position to maximal possible value, effectively
1676                     // marking the variable as undefined.
1677                     initEnv.info.enclVar = v;
1678                     boolean previousCtorPrologue = initEnv.info.ctorPrologue;
1679                     try {
1680                         if (v.owner.kind == TYP && !v.isStatic() && v.isStrict()) {
1681                             // strict instance initializer in a value class
1682                             initEnv.info.ctorPrologue = true;
1683                         }
1684                         attribExpr(tree.init, initEnv, v.type);
1685                         if (tree.isImplicitlyTyped()) {
1686                             //fixup local variable type
1687                             v.type = chk.checkLocalVarType(tree, tree.init.type, tree.name);
1688                         }
1689                     } finally {
1690                         initEnv.info.ctorPrologue = previousCtorPrologue;
1691                     }
1692                 }
1693                 if (allowValueClasses && v.owner.kind == TYP && !v.isStatic()) {
1694                     // strict field initializers are inlined in constructor's prologues
1695                     CtorPrologueVisitor ctorPrologueVisitor = new CtorPrologueVisitor(initEnv,
1696                             !v.isStrict() ? PrologueVisitorMode.WARNINGS_ONLY : PrologueVisitorMode.SUPER_CONSTRUCTOR,
1697                             true);
1698                     ctorPrologueVisitor.scan(tree.init);
1699                 }
1700                 if (tree.isImplicitlyTyped()) {
1701                     setSyntheticVariableType(tree, v.type);
1702                 }
1703             }
1704             result = tree.type = v.type;
1705             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
1706                 if (isNonArgsMethodInObject(v.name)) {
1707                     log.error(tree, Errors.IllegalRecordComponentName(v));
1708                 }
1709             }
1710             chk.checkRequiresIdentity(tree, env.info.lint);
1711         }
1712         finally {
1713             chk.setLint(prevLint);
1714         }
1715     }
1716 
1717     private void doQueueScanTreeAndTypeAnnotateForVarInit(JCVariableDecl tree, Env<AttrContext> env) {
1718         if (tree.init != null &&
1719             (tree.mods.flags & Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED) == 0 &&
1720             env.info.scope.owner.kind != MTH && env.info.scope.owner.kind != VAR) {
1721             tree.mods.flags |= Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED;
1722             // Field initializer expression need to be entered.
1723             annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym);
1724             annotate.flush();
1725         }
1726     }
1727 
1728     private boolean isNonArgsMethodInObject(Name name) {
1729         for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
1730             if (s.type.getParameterTypes().isEmpty()) {
1731                 return true;
1732             }
1733         }
1734         return false;
1735     }
1736 
1737     Fragment canInferLocalVarType(JCVariableDecl tree) {
1738         LocalInitScanner lis = new LocalInitScanner();
1739         lis.scan(tree.init);
1740         return lis.badInferenceMsg;
1741     }
1742 
1743     static class LocalInitScanner extends TreeScanner {
1744         Fragment badInferenceMsg = null;
1745         boolean needsTarget = true;
1746 
1747         @Override
1748         public void visitNewArray(JCNewArray tree) {
1749             if (tree.elemtype == null && needsTarget) {
1750                 badInferenceMsg = Fragments.LocalArrayMissingTarget;
1751             }
1752         }
1753 
1754         @Override
1755         public void visitLambda(JCLambda tree) {
1756             if (needsTarget) {
1757                 badInferenceMsg = Fragments.LocalLambdaMissingTarget;
1758             }
1759         }
1760 
1761         @Override
1762         public void visitTypeCast(JCTypeCast tree) {
1763             boolean prevNeedsTarget = needsTarget;
1764             try {
1765                 needsTarget = false;
1766                 super.visitTypeCast(tree);
1767             } finally {
1768                 needsTarget = prevNeedsTarget;
1769             }
1770         }
1771 
1772         @Override
1773         public void visitReference(JCMemberReference tree) {
1774             if (needsTarget) {
1775                 badInferenceMsg = Fragments.LocalMrefMissingTarget;
1776             }
1777         }
1778 
1779         @Override
1780         public void visitNewClass(JCNewClass tree) {
1781             boolean prevNeedsTarget = needsTarget;
1782             try {
1783                 needsTarget = false;
1784                 super.visitNewClass(tree);
1785             } finally {
1786                 needsTarget = prevNeedsTarget;
1787             }
1788         }
1789 
1790         @Override
1791         public void visitApply(JCMethodInvocation tree) {
1792             boolean prevNeedsTarget = needsTarget;
1793             try {
1794                 needsTarget = false;
1795                 super.visitApply(tree);
1796             } finally {
1797                 needsTarget = prevNeedsTarget;
1798             }
1799         }
1800     }
1801 
1802     public void visitSkip(JCSkip tree) {
1803         result = null;
1804     }
1805 
1806     public void visitBlock(JCBlock tree) {
1807         if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
1808             // Block is a static or instance initializer;
1809             // let the owner of the environment be a freshly
1810             // created BLOCK-method.
1811             Symbol fakeOwner =
1812                 new MethodSymbol(tree.flags | BLOCK |
1813                     env.info.scope.owner.flags() & STRICTFP, names.empty, initBlockType,
1814                     env.info.scope.owner);
1815             final Env<AttrContext> localEnv =
1816                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
1817 
1818             if ((tree.flags & STATIC) != 0) {
1819                 localEnv.info.staticLevel++;
1820             } else {
1821                 localEnv.info.instanceInitializerBlock = true;
1822             }
1823             // Attribute all type annotations in the block
1824             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner);
1825             annotate.flush();
1826             attribStats(tree.stats, localEnv);
1827 
1828             {
1829                 // Store init and clinit type annotations with the ClassSymbol
1830                 // to allow output in Gen.normalizeDefs.
1831                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1832                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1833                 if ((tree.flags & STATIC) != 0) {
1834                     cs.appendClassInitTypeAttributes(tas);
1835                 } else {
1836                     cs.appendInitTypeAttributes(tas);
1837                 }
1838             }
1839         } else {
1840             // Create a new local environment with a local scope.
1841             Env<AttrContext> localEnv =
1842                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1843             try {
1844                 attribStats(tree.stats, localEnv);
1845             } finally {
1846                 localEnv.info.scope.leave();
1847             }
1848         }
1849         result = null;
1850     }
1851 
1852     public void visitDoLoop(JCDoWhileLoop tree) {
1853         attribStat(tree.body, env.dup(tree));
1854         attribExpr(tree.cond, env, syms.booleanType);
1855         handleLoopConditionBindings(matchBindings, tree, tree.body);
1856         result = null;
1857     }
1858 
1859     public void visitWhileLoop(JCWhileLoop tree) {
1860         attribExpr(tree.cond, env, syms.booleanType);
1861         MatchBindings condBindings = matchBindings;
1862         // include condition's bindings when true in the body:
1863         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1864         try {
1865             attribStat(tree.body, whileEnv.dup(tree));
1866         } finally {
1867             whileEnv.info.scope.leave();
1868         }
1869         handleLoopConditionBindings(condBindings, tree, tree.body);
1870         result = null;
1871     }
1872 
1873     public void visitForLoop(JCForLoop tree) {
1874         Env<AttrContext> loopEnv =
1875             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1876         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1877         try {
1878             attribStats(tree.init, loopEnv);
1879             if (tree.cond != null) {
1880                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1881                 // include condition's bindings when true in the body and step:
1882                 condBindings = matchBindings;
1883             }
1884             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1885             try {
1886                 bodyEnv.tree = tree; // before, we were not in loop!
1887                 attribStats(tree.step, bodyEnv);
1888                 attribStat(tree.body, bodyEnv);
1889             } finally {
1890                 bodyEnv.info.scope.leave();
1891             }
1892             result = null;
1893         }
1894         finally {
1895             loopEnv.info.scope.leave();
1896         }
1897         handleLoopConditionBindings(condBindings, tree, tree.body);
1898     }
1899 
1900     /**
1901      * Include condition's bindings when false after the loop, if cannot get out of the loop
1902      */
1903     private void handleLoopConditionBindings(MatchBindings condBindings,
1904                                              JCStatement loop,
1905                                              JCStatement loopBody) {
1906         if (condBindings.bindingsWhenFalse.nonEmpty() &&
1907             !breaksTo(env, loop, loopBody)) {
1908             addBindings2Scope(loop, condBindings.bindingsWhenFalse);
1909         }
1910     }
1911 
1912     private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
1913         preFlow(body);
1914         return flow.breaksToTree(env, loop, body, make);
1915     }
1916 
1917     /**
1918      * Add given bindings to the current scope, unless there's a break to
1919      * an immediately enclosing labeled statement.
1920      */
1921     private void addBindings2Scope(JCStatement introducingStatement,
1922                                    List<BindingSymbol> bindings) {
1923         if (bindings.isEmpty()) {
1924             return ;
1925         }
1926 
1927         var searchEnv = env;
1928         while (searchEnv.tree instanceof JCLabeledStatement labeled &&
1929                labeled.body == introducingStatement) {
1930             if (breaksTo(env, labeled, labeled.body)) {
1931                 //breaking to an immediately enclosing labeled statement
1932                 return ;
1933             }
1934             searchEnv = searchEnv.next;
1935             introducingStatement = labeled;
1936         }
1937 
1938         //include condition's body when false after the while, if cannot get out of the loop
1939         bindings.forEach(env.info.scope::enter);
1940         bindings.forEach(BindingSymbol::preserveBinding);
1941     }
1942 
1943     public void visitForeachLoop(JCEnhancedForLoop tree) {
1944         Env<AttrContext> loopEnv =
1945             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1946         try {
1947             //the Formal Parameter of a for-each loop is not in the scope when
1948             //attributing the for-each expression; we mimic this by attributing
1949             //the for-each expression first (against original scope).
1950             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1951             chk.checkNonVoid(tree.pos(), exprType);
1952             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1953             if (elemtype == null) {
1954                 // or perhaps expr implements Iterable<T>?
1955                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1956                 if (base == null) {
1957                     log.error(tree.expr.pos(),
1958                               Errors.ForeachNotApplicableToType(exprType,
1959                                                                 Fragments.TypeReqArrayOrIterable));
1960                     elemtype = types.createErrorType(exprType);
1961                 } else {
1962                     List<Type> iterableParams = base.allparams();
1963                     elemtype = iterableParams.isEmpty()
1964                         ? syms.objectType
1965                         : types.wildUpperBound(iterableParams.head);
1966 
1967                     // Check the return type of the method iterator().
1968                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1969                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1970                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1971                     if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
1972                         log.error(tree.pos(),
1973                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1974                     }
1975                 }
1976             }
1977             if (tree.var.isImplicitlyTyped()) {
1978                 Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
1979                 setSyntheticVariableType(tree.var, inferredType);
1980             }
1981             attribStat(tree.var, loopEnv);
1982             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1983             loopEnv.tree = tree; // before, we were not in loop!
1984             attribStat(tree.body, loopEnv);
1985             result = null;
1986         }
1987         finally {
1988             loopEnv.info.scope.leave();
1989         }
1990     }
1991 
1992     public void visitLabelled(JCLabeledStatement tree) {
1993         // Check that label is not used in an enclosing statement
1994         Env<AttrContext> env1 = env;
1995         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1996             if (env1.tree.hasTag(LABELLED) &&
1997                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1998                 log.error(tree.pos(),
1999                           Errors.LabelAlreadyInUse(tree.label));
2000                 break;
2001             }
2002             env1 = env1.next;
2003         }
2004 
2005         attribStat(tree.body, env.dup(tree));
2006         result = null;
2007     }
2008 
2009     public void visitSwitch(JCSwitch tree) {
2010         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
2011             attribStats(c.stats, caseEnv);
2012         });
2013         result = null;
2014     }
2015 
2016     public void visitSwitchExpression(JCSwitchExpression tree) {
2017         boolean wrongContext = false;
2018 
2019         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
2020                 PolyKind.STANDALONE : PolyKind.POLY;
2021 
2022         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2023             //this means we are returning a poly conditional from void-compatible lambda expression
2024             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
2025             resultInfo = recoveryInfo;
2026             wrongContext = true;
2027         }
2028 
2029         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2030                 unknownExprInfo :
2031                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
2032 
2033         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
2034         ListBuffer<Type> caseTypes = new ListBuffer<>();
2035 
2036         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
2037             caseEnv.info.yieldResult = condInfo;
2038             attribStats(c.stats, caseEnv);
2039             new TreeScanner() {
2040                 @Override
2041                 public void visitYield(JCYield brk) {
2042                     if (brk.target == tree) {
2043                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
2044                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
2045                     }
2046                     super.visitYield(brk);
2047                 }
2048 
2049                 @Override public void visitClassDef(JCClassDecl tree) {}
2050                 @Override public void visitLambda(JCLambda tree) {}
2051             }.scan(c.stats);
2052         });
2053 
2054         if (tree.cases.isEmpty()) {
2055             log.error(tree.pos(),
2056                       Errors.SwitchExpressionEmpty);
2057         } else if (caseTypes.isEmpty()) {
2058             log.error(tree.pos(),
2059                       Errors.SwitchExpressionNoResultExpressions);
2060         }
2061 
2062         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
2063 
2064         result = tree.type = wrongContext? types.createErrorType(pt()) : check(tree, owntype, KindSelector.VAL, resultInfo);
2065     }
2066     //where:
2067         CheckContext switchExpressionContext(CheckContext checkContext) {
2068             return new Check.NestedCheckContext(checkContext) {
2069                 //this will use enclosing check context to check compatibility of
2070                 //subexpression against target type; if we are in a method check context,
2071                 //depending on whether boxing is allowed, we could have incompatibilities
2072                 @Override
2073                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2074                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
2075                 }
2076             };
2077         }
2078 
2079     private void handleSwitch(JCTree switchTree,
2080                               JCExpression selector,
2081                               List<JCCase> cases,
2082                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
2083         Type seltype = attribExpr(selector, env);
2084         Type seltypeUnboxed = types.unboxedTypeOrType(seltype);
2085 
2086         Env<AttrContext> switchEnv =
2087             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
2088 
2089         try {
2090             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
2091             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
2092             boolean booleanSwitch = types.isSameType(seltypeUnboxed, syms.booleanType);
2093             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
2094             boolean intSwitch = types.isAssignable(seltype, syms.intType);
2095             boolean patternSwitch;
2096             if (seltype.isPrimitive() && !intSwitch) {
2097                 preview.checkSourceLevel(selector.pos(), Feature.PRIMITIVE_PATTERNS);
2098                 patternSwitch = true;
2099             }
2100             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
2101                 !intSwitch) {
2102                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
2103                 patternSwitch = true;
2104             } else {
2105                 patternSwitch = cases.stream()
2106                                      .flatMap(c -> c.labels.stream())
2107                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
2108                                                     TreeInfo.isNullCaseLabel(l));
2109             }
2110 
2111             // Attribute all cases and
2112             // check that there are no duplicate case labels or default clauses.
2113             Set<Object> constants = new HashSet<>(); // The set of case constants.
2114             boolean hasDefault = false;           // Is there a default label?
2115             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
2116             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
2117             boolean hasNullPattern = false;       // Is there a null pattern?
2118             CaseTree.CaseKind caseKind = null;
2119             boolean wasError = false;
2120             JCCaseLabel unconditionalCaseLabel = null;
2121             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
2122                 JCCase c = l.head;
2123                 if (caseKind == null) {
2124                     caseKind = c.caseKind;
2125                 } else if (caseKind != c.caseKind && !wasError) {
2126                     log.error(c.pos(),
2127                               Errors.SwitchMixingCaseTypes);
2128                     wasError = true;
2129                 }
2130                 MatchBindings currentBindings = null;
2131                 MatchBindings guardBindings = null;
2132                 for (List<JCCaseLabel> labels = c.labels; labels.nonEmpty(); labels = labels.tail) {
2133                     JCCaseLabel label = labels.head;
2134                     if (label instanceof JCConstantCaseLabel constLabel) {
2135                         JCExpression expr = constLabel.expr;
2136                         if (TreeInfo.isNull(expr)) {
2137                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
2138                             if (hasNullPattern) {
2139                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
2140                             }
2141                             hasNullPattern = true;
2142                             attribExpr(expr, switchEnv, seltype);
2143                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
2144                         } else if (enumSwitch) {
2145                             Symbol sym = enumConstant(expr, seltype);
2146                             if (sym == null) {
2147                                 if (allowPatternSwitch) {
2148                                     attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
2149                                     Symbol enumSym = TreeInfo.symbol(expr);
2150                                     if (enumSym == null || !enumSym.isEnum() || enumSym.kind != VAR) {
2151                                         log.error(expr.pos(), Errors.EnumLabelMustBeEnumConstant);
2152                                     } else if (!constants.add(enumSym)) {
2153                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
2154                                     }
2155                                 } else {
2156                                     log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
2157                                 }
2158                             } else if (!constants.add(sym)) {
2159                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
2160                             }
2161                         } else if (errorEnumSwitch) {
2162                             //error recovery: the selector is erroneous, and all the case labels
2163                             //are identifiers. This could be an enum switch - don't report resolve
2164                             //error for the case label:
2165                             var prevResolveHelper = rs.basicLogResolveHelper;
2166                             try {
2167                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
2168                                 attribExpr(expr, switchEnv, seltype);
2169                             } finally {
2170                                 rs.basicLogResolveHelper = prevResolveHelper;
2171                             }
2172                         } else {
2173                             Type pattype = attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
2174                             if (!pattype.hasTag(ERROR)) {
2175                                 if (pattype.constValue() == null) {
2176                                     Symbol s = TreeInfo.symbol(expr);
2177                                     if (s != null && s.kind == TYP) {
2178                                         log.error(expr.pos(),
2179                                                   Errors.PatternExpected);
2180                                     } else if (s == null || !s.isEnum()) {
2181                                         log.error(expr.pos(),
2182                                                   (stringSwitch ? Errors.StringConstReq
2183                                                                 : intSwitch ? Errors.ConstExprReq
2184                                                                             : Errors.PatternOrEnumReq));
2185                                     } else if (!constants.add(s)) {
2186                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
2187                                     }
2188                                 }
2189                                 else {
2190                                     boolean isLongFloatDoubleOrBooleanConstant =
2191                                             pattype.getTag().isInSuperClassesOf(LONG) || pattype.getTag().equals(BOOLEAN);
2192                                     if (isLongFloatDoubleOrBooleanConstant) {
2193                                         preview.checkSourceLevel(label.pos(), Feature.PRIMITIVE_PATTERNS);
2194                                     }
2195                                     if (!stringSwitch && !intSwitch && !(isLongFloatDoubleOrBooleanConstant && types.isSameType(seltypeUnboxed, pattype))) {
2196                                         log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
2197                                     } else if (!constants.add(pattype.constValue())) {
2198                                         log.error(c.pos(), Errors.DuplicateCaseLabel);
2199                                     }
2200                                 }
2201                             }
2202                         }
2203                     } else if (label instanceof JCDefaultCaseLabel def) {
2204                         if (hasDefault) {
2205                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
2206                         } else if (hasUnconditionalPattern) {
2207                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
2208                         }  else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
2209                             log.error(label.pos(), Errors.DefaultAndBothBooleanValues);
2210                         }
2211                         hasDefault = true;
2212                         matchBindings = MatchBindingsComputer.EMPTY;
2213                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
2214                         //pattern
2215                         JCPattern pat = patternlabel.pat;
2216                         attribExpr(pat, switchEnv, seltype);
2217                         Type primaryType = TreeInfo.primaryPatternType(pat);
2218 
2219                         if (primaryType.isPrimitive()) {
2220                             preview.checkSourceLevel(pat.pos(), Feature.PRIMITIVE_PATTERNS);
2221                         } else if (!primaryType.hasTag(TYPEVAR)) {
2222                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
2223                         }
2224                         checkCastablePattern(pat.pos(), seltype, primaryType);
2225                         Type patternType = types.erasure(primaryType);
2226                         JCExpression guard = c.guard;
2227                         if (guardBindings == null && guard != null) {
2228                             MatchBindings afterPattern = matchBindings;
2229                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
2230                             try {
2231                                 attribExpr(guard, bodyEnv, syms.booleanType);
2232                             } finally {
2233                                 bodyEnv.info.scope.leave();
2234                             }
2235 
2236                             guardBindings = matchBindings;
2237                             matchBindings = afterPattern;
2238 
2239                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
2240                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
2241                             }
2242                         }
2243                         boolean unguarded = TreeInfo.unguardedCase(c) && !pat.hasTag(RECORDPATTERN);
2244                         boolean unconditional =
2245                                 unguarded &&
2246                                 !patternType.isErroneous() &&
2247                                 types.isUnconditionallyExact(seltype, patternType);
2248                         if (unconditional) {
2249                             if (hasUnconditionalPattern) {
2250                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
2251                             } else if (hasDefault) {
2252                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
2253                             } else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
2254                                 log.error(pat.pos(), Errors.UnconditionalPatternAndBothBooleanValues);
2255                             }
2256                             hasUnconditionalPattern = true;
2257                             unconditionalCaseLabel = label;
2258                         }
2259                         lastPatternErroneous = patternType.isErroneous();
2260                     } else {
2261                         Assert.error();
2262                     }
2263                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
2264                 }
2265 
2266                 if (guardBindings != null) {
2267                     currentBindings = matchBindingsComputer.caseGuard(c, currentBindings, guardBindings);
2268                 }
2269 
2270                 Env<AttrContext> caseEnv =
2271                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
2272                 try {
2273                     attribCase.accept(c, caseEnv);
2274                 } finally {
2275                     caseEnv.info.scope.leave();
2276                 }
2277                 addVars(c.stats, switchEnv.info.scope);
2278 
2279                 preFlow(c);
2280                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
2281             }
2282             if (patternSwitch) {
2283                 chk.checkSwitchCaseStructure(cases);
2284                 chk.checkSwitchCaseLabelDominated(unconditionalCaseLabel, cases);
2285             }
2286             if (switchTree.hasTag(SWITCH)) {
2287                 ((JCSwitch) switchTree).hasUnconditionalPattern =
2288                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
2289                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
2290             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
2291                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
2292                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
2293                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
2294             } else {
2295                 Assert.error(switchTree.getTag().name());
2296             }
2297         } finally {
2298             switchEnv.info.scope.leave();
2299         }
2300     }
2301     // where
2302         private ResultInfo caseLabelResultInfo(Type seltype) {
2303             return new ResultInfo(KindSelector.VAL_TYP,
2304                                   !seltype.hasTag(ERROR) ? seltype
2305                                                          : Type.noType);
2306         }
2307         /** Add any variables defined in stats to the switch scope. */
2308         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
2309             for (;stats.nonEmpty(); stats = stats.tail) {
2310                 JCTree stat = stats.head;
2311                 if (stat.hasTag(VARDEF))
2312                     switchScope.enter(((JCVariableDecl) stat).sym);
2313             }
2314         }
2315     // where
2316     /** Return the selected enumeration constant symbol, or null. */
2317     private Symbol enumConstant(JCTree tree, Type enumType) {
2318         if (tree.hasTag(IDENT)) {
2319             JCIdent ident = (JCIdent)tree;
2320             Name name = ident.name;
2321             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
2322                 if (sym.kind == VAR) {
2323                     Symbol s = ident.sym = sym;
2324                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
2325                     ident.type = s.type;
2326                     return ((s.flags_field & Flags.ENUM) == 0)
2327                         ? null : s;
2328                 }
2329             }
2330         }
2331         return null;
2332     }
2333 
2334     public void visitSynchronized(JCSynchronized tree) {
2335         boolean identityType = chk.checkIdentityType(tree.pos(), attribExpr(tree.lock, env));
2336         if (identityType && tree.lock.type != null && tree.lock.type.isValueBased()) {
2337             log.warning(tree.pos(), LintWarnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
2338         }
2339         attribStat(tree.body, env);
2340         result = null;
2341     }
2342 
2343     public void visitTry(JCTry tree) {
2344         // Create a new local environment with a local
2345         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
2346         try {
2347             boolean isTryWithResource = tree.resources.nonEmpty();
2348             // Create a nested environment for attributing the try block if needed
2349             Env<AttrContext> tryEnv = isTryWithResource ?
2350                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
2351                 localEnv;
2352             try {
2353                 // Attribute resource declarations
2354                 for (JCTree resource : tree.resources) {
2355                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
2356                         @Override
2357                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
2358                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
2359                         }
2360                     };
2361                     ResultInfo twrResult =
2362                         new ResultInfo(KindSelector.VAR,
2363                                        syms.autoCloseableType,
2364                                        twrContext);
2365                     if (resource.hasTag(VARDEF)) {
2366                         attribStat(resource, tryEnv);
2367                         twrResult.check(resource, resource.type);
2368 
2369                         //check that resource type cannot throw InterruptedException
2370                         checkAutoCloseable(localEnv, resource, true);
2371 
2372                         VarSymbol var = ((JCVariableDecl) resource).sym;
2373 
2374                         var.flags_field |= Flags.FINAL;
2375                         var.setData(ElementKind.RESOURCE_VARIABLE);
2376                     } else {
2377                         attribTree(resource, tryEnv, twrResult);
2378                     }
2379                 }
2380                 // Attribute body
2381                 attribStat(tree.body, tryEnv);
2382             } finally {
2383                 if (isTryWithResource)
2384                     tryEnv.info.scope.leave();
2385             }
2386 
2387             // Attribute catch clauses
2388             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
2389                 JCCatch c = l.head;
2390                 Env<AttrContext> catchEnv =
2391                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
2392                 try {
2393                     Type ctype = attribStat(c.param, catchEnv);
2394                     if (TreeInfo.isMultiCatch(c)) {
2395                         //multi-catch parameter is implicitly marked as final
2396                         c.param.sym.flags_field |= FINAL | UNION;
2397                     }
2398                     if (c.param.sym.kind == VAR) {
2399                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
2400                     }
2401                     chk.checkType(c.param.vartype.pos(),
2402                                   chk.checkClassType(c.param.vartype.pos(), ctype),
2403                                   syms.throwableType);
2404                     attribStat(c.body, catchEnv);
2405                 } finally {
2406                     catchEnv.info.scope.leave();
2407                 }
2408             }
2409 
2410             // Attribute finalizer
2411             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
2412             result = null;
2413         }
2414         finally {
2415             localEnv.info.scope.leave();
2416         }
2417     }
2418 
2419     void checkAutoCloseable(Env<AttrContext> env, JCTree tree, boolean useSite) {
2420         DiagnosticPosition pos = tree.pos();
2421         Type resource = tree.type;
2422         if (!resource.isErroneous() &&
2423             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
2424             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
2425             Symbol close = syms.noSymbol;
2426             Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
2427             try {
2428                 close = rs.resolveQualifiedMethod(pos,
2429                         env,
2430                         types.skipTypeVars(resource, false),
2431                         names.close,
2432                         List.nil(),
2433                         List.nil());
2434             }
2435             finally {
2436                 log.popDiagnosticHandler(discardHandler);
2437             }
2438             if (close.kind == MTH &&
2439                     (useSite || close.owner != syms.autoCloseableType.tsym) &&
2440                     ((MethodSymbol)close).binaryOverrides(syms.autoCloseableClose, resource.tsym, types) &&
2441                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes())) {
2442                 if (!useSite && close.owner == resource.tsym) {
2443                     log.warning(TreeInfo.diagnosticPositionFor(close, tree),
2444                         LintWarnings.TryResourceCanThrowInterruptedExc(resource));
2445                 } else {
2446                     log.warning(pos, LintWarnings.TryResourceThrowsInterruptedExc(resource));
2447                 }
2448             }
2449         }
2450     }
2451 
2452     public void visitConditional(JCConditional tree) {
2453         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2454         MatchBindings condBindings = matchBindings;
2455 
2456         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2457                 isBooleanOrNumeric(env, tree)) ?
2458                 PolyKind.STANDALONE : PolyKind.POLY;
2459 
2460         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2461             //this means we are returning a poly conditional from void-compatible lambda expression
2462             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2463             result = tree.type = types.createErrorType(resultInfo.pt);
2464             return;
2465         }
2466 
2467         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2468                 unknownExprInfo :
2469                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2470 
2471 
2472         // x ? y : z
2473         // include x's bindings when true in y
2474         // include x's bindings when false in z
2475 
2476         Type truetype;
2477         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2478         try {
2479             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2480         } finally {
2481             trueEnv.info.scope.leave();
2482         }
2483 
2484         MatchBindings trueBindings = matchBindings;
2485 
2486         Type falsetype;
2487         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2488         try {
2489             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2490         } finally {
2491             falseEnv.info.scope.leave();
2492         }
2493 
2494         MatchBindings falseBindings = matchBindings;
2495 
2496         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2497                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2498                          List.of(truetype, falsetype)) : pt();
2499         if (condtype.constValue() != null &&
2500                 truetype.constValue() != null &&
2501                 falsetype.constValue() != null &&
2502                 !owntype.hasTag(NONE)) {
2503             //constant folding
2504             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2505         }
2506         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2507         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2508     }
2509     //where
2510         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2511             switch (tree.getTag()) {
2512                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2513                               ((JCLiteral)tree).typetag == BOOLEAN ||
2514                               ((JCLiteral)tree).typetag == BOT;
2515                 case LAMBDA: case REFERENCE: return false;
2516                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2517                 case CONDEXPR:
2518                     JCConditional condTree = (JCConditional)tree;
2519                     return isBooleanOrNumeric(env, condTree.truepart) &&
2520                             isBooleanOrNumeric(env, condTree.falsepart);
2521                 case APPLY:
2522                     JCMethodInvocation speculativeMethodTree =
2523                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2524                                     tree, env, unknownExprInfo,
2525                                     argumentAttr.withLocalCacheContext());
2526                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2527                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2528                             env.enclClass.type :
2529                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2530                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2531                     return primitiveOrBoxed(owntype);
2532                 case NEWCLASS:
2533                     JCExpression className =
2534                             removeClassParams.translate(((JCNewClass)tree).clazz);
2535                     JCExpression speculativeNewClassTree =
2536                             (JCExpression)deferredAttr.attribSpeculative(
2537                                     className, env, unknownTypeInfo,
2538                                     argumentAttr.withLocalCacheContext());
2539                     return primitiveOrBoxed(speculativeNewClassTree.type);
2540                 default:
2541                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2542                             argumentAttr.withLocalCacheContext()).type;
2543                     return primitiveOrBoxed(speculativeType);
2544             }
2545         }
2546         //where
2547             boolean primitiveOrBoxed(Type t) {
2548                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2549             }
2550 
2551             TreeTranslator removeClassParams = new TreeTranslator() {
2552                 @Override
2553                 public void visitTypeApply(JCTypeApply tree) {
2554                     result = translate(tree.clazz);
2555                 }
2556             };
2557 
2558         CheckContext conditionalContext(CheckContext checkContext) {
2559             return new Check.NestedCheckContext(checkContext) {
2560                 //this will use enclosing check context to check compatibility of
2561                 //subexpression against target type; if we are in a method check context,
2562                 //depending on whether boxing is allowed, we could have incompatibilities
2563                 @Override
2564                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2565                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2566                 }
2567             };
2568         }
2569 
2570         /** Compute the type of a conditional expression, after
2571          *  checking that it exists.  See JLS 15.25. Does not take into
2572          *  account the special case where condition and both arms
2573          *  are constants.
2574          *
2575          *  @param pos      The source position to be used for error
2576          *                  diagnostics.
2577          *  @param thentype The type of the expression's then-part.
2578          *  @param elsetype The type of the expression's else-part.
2579          */
2580         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2581             if (condTypes.isEmpty()) {
2582                 return syms.objectType; //TODO: how to handle?
2583             }
2584             Type first = condTypes.head;
2585             // If same type, that is the result
2586             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2587                 return first.baseType();
2588 
2589             List<Type> unboxedTypes = condTypes.stream()
2590                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2591                                                .collect(List.collector());
2592 
2593             // Otherwise, if both arms can be converted to a numeric
2594             // type, return the least numeric type that fits both arms
2595             // (i.e. return larger of the two, or return int if one
2596             // arm is short, the other is char).
2597             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2598                 // If one arm has an integer subrange type (i.e., byte,
2599                 // short, or char), and the other is an integer constant
2600                 // that fits into the subrange, return the subrange type.
2601                 for (Type type : unboxedTypes) {
2602                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2603                         continue;
2604                     }
2605                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2606                         return type.baseType();
2607                 }
2608 
2609                 for (TypeTag tag : primitiveTags) {
2610                     Type candidate = syms.typeOfTag[tag.ordinal()];
2611                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2612                         return candidate;
2613                     }
2614                 }
2615             }
2616 
2617             // Those were all the cases that could result in a primitive
2618             condTypes = condTypes.stream()
2619                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
2620                                  .collect(List.collector());
2621 
2622             for (Type type : condTypes) {
2623                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2624                     return type.baseType();
2625             }
2626 
2627             Iterator<DiagnosticPosition> posIt = positions.iterator();
2628 
2629             condTypes = condTypes.stream()
2630                                  .map(t -> chk.checkNonVoid(posIt.next(), t))
2631                                  .collect(List.collector());
2632 
2633             // both are known to be reference types.  The result is
2634             // lub(thentype,elsetype). This cannot fail, as it will
2635             // always be possible to infer "Object" if nothing better.
2636             return types.lub(condTypes.stream()
2637                         .map(t -> t.baseType())
2638                         .filter(t -> !t.hasTag(BOT))
2639                         .collect(List.collector()));
2640         }
2641 
2642     static final TypeTag[] primitiveTags = new TypeTag[]{
2643         BYTE,
2644         CHAR,
2645         SHORT,
2646         INT,
2647         LONG,
2648         FLOAT,
2649         DOUBLE,
2650         BOOLEAN,
2651     };
2652 
2653     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2654         return bindingEnv(env, env.tree, bindings);
2655     }
2656 
2657     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2658         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2659         bindings.forEach(env1.info.scope::enter);
2660         return env1;
2661     }
2662 
2663     public void visitIf(JCIf tree) {
2664         attribExpr(tree.cond, env, syms.booleanType);
2665 
2666         // if (x) { y } [ else z ]
2667         // include x's bindings when true in y
2668         // include x's bindings when false in z
2669 
2670         MatchBindings condBindings = matchBindings;
2671         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2672 
2673         try {
2674             attribStat(tree.thenpart, thenEnv);
2675         } finally {
2676             thenEnv.info.scope.leave();
2677         }
2678 
2679         preFlow(tree.thenpart);
2680         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2681         boolean aliveAfterElse;
2682 
2683         if (tree.elsepart != null) {
2684             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2685             try {
2686                 attribStat(tree.elsepart, elseEnv);
2687             } finally {
2688                 elseEnv.info.scope.leave();
2689             }
2690             preFlow(tree.elsepart);
2691             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2692         } else {
2693             aliveAfterElse = true;
2694         }
2695 
2696         chk.checkEmptyIf(tree);
2697 
2698         List<BindingSymbol> afterIfBindings = List.nil();
2699 
2700         if (aliveAfterThen && !aliveAfterElse) {
2701             afterIfBindings = condBindings.bindingsWhenTrue;
2702         } else if (aliveAfterElse && !aliveAfterThen) {
2703             afterIfBindings = condBindings.bindingsWhenFalse;
2704         }
2705 
2706         addBindings2Scope(tree, afterIfBindings);
2707 
2708         result = null;
2709     }
2710 
2711         void preFlow(JCTree tree) {
2712             attrRecover.doRecovery();
2713             new PostAttrAnalyzer() {
2714                 @Override
2715                 public void scan(JCTree tree) {
2716                     if (tree == null ||
2717                             (tree.type != null &&
2718                             tree.type == Type.stuckType)) {
2719                         //don't touch stuck expressions!
2720                         return;
2721                     }
2722                     super.scan(tree);
2723                 }
2724 
2725                 @Override
2726                 public void visitClassDef(JCClassDecl that) {
2727                     if (that.sym != null) {
2728                         // Method preFlow shouldn't visit class definitions
2729                         // that have not been entered and attributed.
2730                         // See JDK-8254557 and JDK-8203277 for more details.
2731                         super.visitClassDef(that);
2732                     }
2733                 }
2734 
2735                 @Override
2736                 public void visitLambda(JCLambda that) {
2737                     if (that.type != null) {
2738                         // Method preFlow shouldn't visit lambda expressions
2739                         // that have not been entered and attributed.
2740                         // See JDK-8254557 and JDK-8203277 for more details.
2741                         super.visitLambda(that);
2742                     }
2743                 }
2744             }.scan(tree);
2745         }
2746 
2747     public void visitExec(JCExpressionStatement tree) {
2748         //a fresh environment is required for 292 inference to work properly ---
2749         //see Infer.instantiatePolymorphicSignatureInstance()
2750         Env<AttrContext> localEnv = env.dup(tree);
2751         attribExpr(tree.expr, localEnv);
2752         result = null;
2753     }
2754 
2755     public void visitBreak(JCBreak tree) {
2756         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2757         result = null;
2758     }
2759 
2760     public void visitYield(JCYield tree) {
2761         if (env.info.yieldResult != null) {
2762             attribTree(tree.value, env, env.info.yieldResult);
2763             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2764         } else {
2765             log.error(tree.pos(), tree.value.hasTag(PARENS)
2766                     ? Errors.NoSwitchExpressionQualify
2767                     : Errors.NoSwitchExpression);
2768             attribTree(tree.value, env, unknownExprInfo);
2769         }
2770         result = null;
2771     }
2772 
2773     public void visitContinue(JCContinue tree) {
2774         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2775         result = null;
2776     }
2777     //where
2778         /** Return the target of a break, continue or yield statement,
2779          *  if it exists, report an error if not.
2780          *  Note: The target of a labelled break or continue is the
2781          *  (non-labelled) statement tree referred to by the label,
2782          *  not the tree representing the labelled statement itself.
2783          *
2784          *  @param pos     The position to be used for error diagnostics
2785          *  @param tag     The tag of the jump statement. This is either
2786          *                 Tree.BREAK or Tree.CONTINUE.
2787          *  @param label   The label of the jump statement, or null if no
2788          *                 label is given.
2789          *  @param env     The environment current at the jump statement.
2790          */
2791         private JCTree findJumpTarget(DiagnosticPosition pos,
2792                                                    JCTree.Tag tag,
2793                                                    Name label,
2794                                                    Env<AttrContext> env) {
2795             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2796 
2797             if (jumpTarget.snd != null) {
2798                 log.error(pos, jumpTarget.snd);
2799             }
2800 
2801             return jumpTarget.fst;
2802         }
2803         /** Return the target of a break or continue statement, if it exists,
2804          *  report an error if not.
2805          *  Note: The target of a labelled break or continue is the
2806          *  (non-labelled) statement tree referred to by the label,
2807          *  not the tree representing the labelled statement itself.
2808          *
2809          *  @param tag     The tag of the jump statement. This is either
2810          *                 Tree.BREAK or Tree.CONTINUE.
2811          *  @param label   The label of the jump statement, or null if no
2812          *                 label is given.
2813          *  @param env     The environment current at the jump statement.
2814          */
2815         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2816                                                                        Name label,
2817                                                                        Env<AttrContext> env) {
2818             // Search environments outwards from the point of jump.
2819             Env<AttrContext> env1 = env;
2820             JCDiagnostic.Error pendingError = null;
2821             LOOP:
2822             while (env1 != null) {
2823                 switch (env1.tree.getTag()) {
2824                     case LABELLED:
2825                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2826                         if (label == labelled.label) {
2827                             // If jump is a continue, check that target is a loop.
2828                             if (tag == CONTINUE) {
2829                                 if (!labelled.body.hasTag(DOLOOP) &&
2830                                         !labelled.body.hasTag(WHILELOOP) &&
2831                                         !labelled.body.hasTag(FORLOOP) &&
2832                                         !labelled.body.hasTag(FOREACHLOOP)) {
2833                                     pendingError = Errors.NotLoopLabel(label);
2834                                 }
2835                                 // Found labelled statement target, now go inwards
2836                                 // to next non-labelled tree.
2837                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2838                             } else {
2839                                 return Pair.of(labelled, pendingError);
2840                             }
2841                         }
2842                         break;
2843                     case DOLOOP:
2844                     case WHILELOOP:
2845                     case FORLOOP:
2846                     case FOREACHLOOP:
2847                         if (label == null) return Pair.of(env1.tree, pendingError);
2848                         break;
2849                     case SWITCH:
2850                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2851                         break;
2852                     case SWITCH_EXPRESSION:
2853                         if (tag == YIELD) {
2854                             return Pair.of(env1.tree, null);
2855                         } else if (tag == BREAK) {
2856                             pendingError = Errors.BreakOutsideSwitchExpression;
2857                         } else {
2858                             pendingError = Errors.ContinueOutsideSwitchExpression;
2859                         }
2860                         break;
2861                     case LAMBDA:
2862                     case METHODDEF:
2863                     case CLASSDEF:
2864                         break LOOP;
2865                     default:
2866                 }
2867                 env1 = env1.next;
2868             }
2869             if (label != null)
2870                 return Pair.of(null, Errors.UndefLabel(label));
2871             else if (pendingError != null)
2872                 return Pair.of(null, pendingError);
2873             else if (tag == CONTINUE)
2874                 return Pair.of(null, Errors.ContOutsideLoop);
2875             else
2876                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2877         }
2878 
2879     public void visitReturn(JCReturn tree) {
2880         // Check that there is an enclosing method which is
2881         // nested within than the enclosing class.
2882         if (env.info.returnResult == null) {
2883             log.error(tree.pos(), Errors.RetOutsideMeth);
2884         } else if (env.info.yieldResult != null) {
2885             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2886             if (tree.expr != null) {
2887                 attribExpr(tree.expr, env, env.info.yieldResult.pt);
2888             }
2889         } else if (!env.info.isLambda &&
2890                 env.enclMethod != null &&
2891                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2892             log.error(env.enclMethod,
2893                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2894         } else {
2895             // Attribute return expression, if it exists, and check that
2896             // it conforms to result type of enclosing method.
2897             if (tree.expr != null) {
2898                 if (env.info.returnResult.pt.hasTag(VOID)) {
2899                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2900                               diags.fragment(Fragments.UnexpectedRetVal));
2901                 }
2902                 attribTree(tree.expr, env, env.info.returnResult);
2903             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2904                     !env.info.returnResult.pt.hasTag(NONE)) {
2905                 env.info.returnResult.checkContext.report(tree.pos(),
2906                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2907             }
2908         }
2909         result = null;
2910     }
2911 
2912     public void visitThrow(JCThrow tree) {
2913         Type owntype = attribExpr(tree.expr, env, Type.noType);
2914         chk.checkType(tree, owntype, syms.throwableType);
2915         result = null;
2916     }
2917 
2918     public void visitAssert(JCAssert tree) {
2919         attribExpr(tree.cond, env, syms.booleanType);
2920         if (tree.detail != null) {
2921             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2922         }
2923         result = null;
2924     }
2925 
2926      /** Visitor method for method invocations.
2927      *  NOTE: The method part of an application will have in its type field
2928      *        the return type of the method, not the method's type itself!
2929      */
2930     public void visitApply(JCMethodInvocation tree) {
2931         // The local environment of a method application is
2932         // a new environment nested in the current one.
2933         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2934 
2935         // The types of the actual method arguments.
2936         List<Type> argtypes;
2937 
2938         // The types of the actual method type arguments.
2939         List<Type> typeargtypes = null;
2940 
2941         Name methName = TreeInfo.name(tree.meth);
2942 
2943         boolean isConstructorCall =
2944             methName == names._this || methName == names._super;
2945 
2946         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2947         if (isConstructorCall) {
2948 
2949             // Attribute arguments, yielding list of argument types.
2950             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2951             argtypes = argtypesBuf.toList();
2952             typeargtypes = attribTypes(tree.typeargs, localEnv);
2953 
2954             // Done with this()/super() parameters. End of constructor prologue.
2955             env.info.ctorPrologue = false;
2956 
2957             // Variable `site' points to the class in which the called
2958             // constructor is defined.
2959             Type site = env.enclClass.sym.type;
2960             if (methName == names._super) {
2961                 if (site == syms.objectType) {
2962                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2963                     site = types.createErrorType(syms.objectType);
2964                 } else {
2965                     site = types.supertype(site);
2966                 }
2967             }
2968 
2969             if (site.hasTag(CLASS)) {
2970                 Type encl = site.getEnclosingType();
2971                 while (encl != null && encl.hasTag(TYPEVAR))
2972                     encl = encl.getUpperBound();
2973                 if (encl.hasTag(CLASS)) {
2974                     // we are calling a nested class
2975 
2976                     if (tree.meth.hasTag(SELECT)) {
2977                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2978 
2979                         // We are seeing a prefixed call, of the form
2980                         //     <expr>.super(...).
2981                         // Check that the prefix expression conforms
2982                         // to the outer instance type of the class.
2983                         chk.checkRefType(qualifier.pos(),
2984                                          attribExpr(qualifier, localEnv,
2985                                                     encl));
2986                     }
2987                 } else if (tree.meth.hasTag(SELECT)) {
2988                     log.error(tree.meth.pos(),
2989                               Errors.IllegalQualNotIcls(site.tsym));
2990                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2991                 }
2992 
2993                 if (tree.meth.hasTag(IDENT)) {
2994                     // non-qualified super(...) call; check whether explicit constructor
2995                     // invocation is well-formed. If the super class is an inner class,
2996                     // make sure that an appropriate implicit qualifier exists. If the super
2997                     // class is a local class, make sure that the current class is defined
2998                     // in the same context as the local class.
2999                     checkNewInnerClass(tree.meth.pos(), localEnv, site, true);
3000                 }
3001 
3002                 // if we're calling a java.lang.Enum constructor,
3003                 // prefix the implicit String and int parameters
3004                 if (site.tsym == syms.enumSym)
3005                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
3006 
3007                 // Resolve the called constructor under the assumption
3008                 // that we are referring to a superclass instance of the
3009                 // current instance (JLS ???).
3010                 boolean selectSuperPrev = localEnv.info.selectSuper;
3011                 localEnv.info.selectSuper = true;
3012                 localEnv.info.pendingResolutionPhase = null;
3013                 Symbol sym = rs.resolveConstructor(
3014                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
3015                 localEnv.info.selectSuper = selectSuperPrev;
3016 
3017                 // Set method symbol to resolved constructor...
3018                 TreeInfo.setSymbol(tree.meth, sym);
3019 
3020                 // ...and check that it is legal in the current context.
3021                 // (this will also set the tree's type)
3022                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
3023                 checkId(tree.meth, site, sym, localEnv,
3024                         new ResultInfo(kind, mpt));
3025             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
3026                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
3027             }
3028             // Otherwise, `site' is an error type and we do nothing
3029             result = tree.type = syms.voidType;
3030         } else {
3031             // Otherwise, we are seeing a regular method call.
3032             // Attribute the arguments, yielding list of argument types, ...
3033             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
3034             argtypes = argtypesBuf.toList();
3035             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
3036 
3037             // ... and attribute the method using as a prototype a methodtype
3038             // whose formal argument types is exactly the list of actual
3039             // arguments (this will also set the method symbol).
3040             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
3041             localEnv.info.pendingResolutionPhase = null;
3042             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
3043 
3044             // Compute the result type.
3045             Type restype = mtype.getReturnType();
3046             if (restype.hasTag(WILDCARD))
3047                 throw new AssertionError(mtype);
3048 
3049             Type qualifier = (tree.meth.hasTag(SELECT))
3050                     ? ((JCFieldAccess) tree.meth).selected.type
3051                     : env.enclClass.sym.type;
3052             Symbol msym = TreeInfo.symbol(tree.meth);
3053             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
3054 
3055             chk.checkRefTypes(tree.typeargs, typeargtypes);
3056 
3057             // Check that value of resulting type is admissible in the
3058             // current context.  Also, capture the return type
3059             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
3060             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
3061         }
3062         chk.checkRequiresIdentity(tree, env.info.lint);
3063         chk.validate(tree.typeargs, localEnv);
3064     }
3065     //where
3066         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
3067             if (msym != null &&
3068                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
3069                     methodName == names.getClass &&
3070                     argtypes.isEmpty()) {
3071                 // as a special case, x.getClass() has type Class<? extends |X|>
3072                 return new ClassType(restype.getEnclosingType(),
3073                         List.of(new WildcardType(types.erasure(qualifierType.baseType()),
3074                                 BoundKind.EXTENDS,
3075                                 syms.boundClass)),
3076                         restype.tsym,
3077                         restype.getMetadata());
3078             } else if (msym != null &&
3079                     msym.owner == syms.arrayClass &&
3080                     methodName == names.clone &&
3081                     types.isArray(qualifierType)) {
3082                 // as a special case, array.clone() has a result that is
3083                 // the same as static type of the array being cloned
3084                 return qualifierType;
3085             } else {
3086                 return restype;
3087             }
3088         }
3089 
3090         /** Obtain a method type with given argument types.
3091          */
3092         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
3093             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
3094             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
3095         }
3096 
3097     public void visitNewClass(final JCNewClass tree) {
3098         Type owntype = types.createErrorType(tree.type);
3099 
3100         // The local environment of a class creation is
3101         // a new environment nested in the current one.
3102         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
3103 
3104         // The anonymous inner class definition of the new expression,
3105         // if one is defined by it.
3106         JCClassDecl cdef = tree.def;
3107 
3108         // If enclosing class is given, attribute it, and
3109         // complete class name to be fully qualified
3110         JCExpression clazz = tree.clazz; // Class field following new
3111         JCExpression clazzid;            // Identifier in class field
3112         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
3113         annoclazzid = null;
3114 
3115         if (clazz.hasTag(TYPEAPPLY)) {
3116             clazzid = ((JCTypeApply) clazz).clazz;
3117             if (clazzid.hasTag(ANNOTATED_TYPE)) {
3118                 annoclazzid = (JCAnnotatedType) clazzid;
3119                 clazzid = annoclazzid.underlyingType;
3120             }
3121         } else {
3122             if (clazz.hasTag(ANNOTATED_TYPE)) {
3123                 annoclazzid = (JCAnnotatedType) clazz;
3124                 clazzid = annoclazzid.underlyingType;
3125             } else {
3126                 clazzid = clazz;
3127             }
3128         }
3129 
3130         JCExpression clazzid1 = clazzid; // The same in fully qualified form
3131 
3132         if (tree.encl != null) {
3133             // We are seeing a qualified new, of the form
3134             //    <expr>.new C <...> (...) ...
3135             // In this case, we let clazz stand for the name of the
3136             // allocated class C prefixed with the type of the qualifier
3137             // expression, so that we can
3138             // resolve it with standard techniques later. I.e., if
3139             // <expr> has type T, then <expr>.new C <...> (...)
3140             // yields a clazz T.C.
3141             Type encltype = chk.checkRefType(tree.encl.pos(),
3142                                              attribExpr(tree.encl, env));
3143             // TODO 308: in <expr>.new C, do we also want to add the type annotations
3144             // from expr to the combined type, or not? Yes, do this.
3145             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
3146                                                  ((JCIdent) clazzid).name);
3147 
3148             EndPosTable endPosTable = this.env.toplevel.endPositions;
3149             endPosTable.storeEnd(clazzid1, clazzid.getEndPosition(endPosTable));
3150             if (clazz.hasTag(ANNOTATED_TYPE)) {
3151                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
3152                 List<JCAnnotation> annos = annoType.annotations;
3153 
3154                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
3155                     clazzid1 = make.at(tree.pos).
3156                         TypeApply(clazzid1,
3157                                   ((JCTypeApply) clazz).arguments);
3158                 }
3159 
3160                 clazzid1 = make.at(tree.pos).
3161                     AnnotatedType(annos, clazzid1);
3162             } else if (clazz.hasTag(TYPEAPPLY)) {
3163                 clazzid1 = make.at(tree.pos).
3164                     TypeApply(clazzid1,
3165                               ((JCTypeApply) clazz).arguments);
3166             }
3167 
3168             clazz = clazzid1;
3169         }
3170 
3171         // Attribute clazz expression and store
3172         // symbol + type back into the attributed tree.
3173         Type clazztype = TreeInfo.isEnumInit(env.tree) ?
3174             attribIdentAsEnumType(env, (JCIdent)clazz) :
3175             attribType(clazz, env);
3176 
3177         clazztype = chk.checkDiamond(tree, clazztype);
3178         chk.validate(clazz, localEnv);
3179         if (tree.encl != null) {
3180             // We have to work in this case to store
3181             // symbol + type back into the attributed tree.
3182             tree.clazz.type = clazztype;
3183             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
3184             clazzid.type = ((JCIdent) clazzid).sym.type;
3185             if (annoclazzid != null) {
3186                 annoclazzid.type = clazzid.type;
3187             }
3188             if (!clazztype.isErroneous()) {
3189                 if (cdef != null && clazztype.tsym.isInterface()) {
3190                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
3191                 } else if (clazztype.tsym.isStatic()) {
3192                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
3193                 }
3194             }
3195         } else {
3196             // Check for the existence of an apropos outer instance
3197             checkNewInnerClass(tree.pos(), env, clazztype, false);
3198         }
3199 
3200         // Attribute constructor arguments.
3201         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
3202         final KindSelector pkind =
3203             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
3204         List<Type> argtypes = argtypesBuf.toList();
3205         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
3206 
3207         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
3208             // Enums may not be instantiated except implicitly
3209             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
3210                 (!env.tree.hasTag(VARDEF) ||
3211                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
3212                  ((JCVariableDecl) env.tree).init != tree))
3213                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
3214 
3215             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
3216                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3217             boolean skipNonDiamondPath = false;
3218             // Check that class is not abstract
3219             if (cdef == null && !tree.classDeclRemoved() && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
3220                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
3221                 log.error(tree.pos(),
3222                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
3223                 skipNonDiamondPath = true;
3224             } else if (cdef != null && clazztype.tsym.isInterface()) {
3225                 // Check that no constructor arguments are given to
3226                 // anonymous classes implementing an interface
3227                 if (!argtypes.isEmpty())
3228                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
3229 
3230                 if (!typeargtypes.isEmpty())
3231                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
3232 
3233                 // Error recovery: pretend no arguments were supplied.
3234                 argtypes = List.nil();
3235                 typeargtypes = List.nil();
3236                 skipNonDiamondPath = true;
3237             }
3238             if (TreeInfo.isDiamond(tree)) {
3239                 ClassType site = new ClassType(clazztype.getEnclosingType(),
3240                             clazztype.tsym.type.getTypeArguments(),
3241                                                clazztype.tsym,
3242                                                clazztype.getMetadata());
3243 
3244                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
3245                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
3246                 diamondEnv.info.pendingResolutionPhase = null;
3247 
3248                 //if the type of the instance creation expression is a class type
3249                 //apply method resolution inference (JLS 15.12.2.7). The return type
3250                 //of the resolved constructor will be a partially instantiated type
3251                 Symbol constructor = rs.resolveDiamond(tree.pos(),
3252                             diamondEnv,
3253                             site,
3254                             argtypes,
3255                             typeargtypes);
3256                 tree.constructor = constructor.baseSymbol();
3257 
3258                 final TypeSymbol csym = clazztype.tsym;
3259                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
3260                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3261                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
3262                 constructorType = checkId(tree, site,
3263                         constructor,
3264                         diamondEnv,
3265                         diamondResult);
3266 
3267                 tree.clazz.type = types.createErrorType(clazztype);
3268                 if (!constructorType.isErroneous()) {
3269                     tree.clazz.type = clazz.type = constructorType.getReturnType();
3270                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
3271                 }
3272                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
3273             }
3274 
3275             // Resolve the called constructor under the assumption
3276             // that we are referring to a superclass instance of the
3277             // current instance (JLS ???).
3278             else if (!skipNonDiamondPath) {
3279                 //the following code alters some of the fields in the current
3280                 //AttrContext - hence, the current context must be dup'ed in
3281                 //order to avoid downstream failures
3282                 Env<AttrContext> rsEnv = localEnv.dup(tree);
3283                 rsEnv.info.selectSuper = cdef != null;
3284                 rsEnv.info.pendingResolutionPhase = null;
3285                 tree.constructor = rs.resolveConstructor(
3286                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
3287                 if (cdef == null) { //do not check twice!
3288                     tree.constructorType = checkId(tree,
3289                             clazztype,
3290                             tree.constructor,
3291                             rsEnv,
3292                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3293                     if (rsEnv.info.lastResolveVarargs())
3294                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
3295                 }
3296             }
3297 
3298             chk.checkRequiresIdentity(tree, env.info.lint);
3299 
3300             if (cdef != null) {
3301                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
3302                 return;
3303             }
3304 
3305             if (tree.constructor != null && tree.constructor.kind == MTH)
3306                 owntype = clazztype;
3307         }
3308         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3309         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
3310         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
3311             //we need to wait for inference to finish and then replace inference vars in the constructor type
3312             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
3313                     instantiatedContext -> {
3314                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
3315                     });
3316         }
3317         chk.validate(tree.typeargs, localEnv);
3318     }
3319 
3320         // where
3321         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
3322                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
3323                                                    List<Type> argtypes, List<Type> typeargtypes,
3324                                                    KindSelector pkind) {
3325             // We are seeing an anonymous class instance creation.
3326             // In this case, the class instance creation
3327             // expression
3328             //
3329             //    E.new <typeargs1>C<typargs2>(args) { ... }
3330             //
3331             // is represented internally as
3332             //
3333             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
3334             //
3335             // This expression is then *transformed* as follows:
3336             //
3337             // (1) add an extends or implements clause
3338             // (2) add a constructor.
3339             //
3340             // For instance, if C is a class, and ET is the type of E,
3341             // the expression
3342             //
3343             //    E.new <typeargs1>C<typargs2>(args) { ... }
3344             //
3345             // is translated to (where X is a fresh name and typarams is the
3346             // parameter list of the super constructor):
3347             //
3348             //   new <typeargs1>X(<*nullchk*>E, args) where
3349             //     X extends C<typargs2> {
3350             //       <typarams> X(ET e, args) {
3351             //         e.<typeargs1>super(args)
3352             //       }
3353             //       ...
3354             //     }
3355             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
3356             Type enclType = clazztype.getEnclosingType();
3357             if (enclType != null &&
3358                     enclType.hasTag(CLASS) &&
3359                     !chk.checkDenotable((ClassType)enclType)) {
3360                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
3361             }
3362             final boolean isDiamond = TreeInfo.isDiamond(tree);
3363             if (isDiamond
3364                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
3365                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
3366                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
3367                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
3368                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
3369                         instantiatedContext -> {
3370                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
3371                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
3372                             ResultInfo prevResult = this.resultInfo;
3373                             try {
3374                                 this.resultInfo = resultInfoForClassDefinition;
3375                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
3376                                         dupLocalEnv, argtypes, typeargtypes, pkind);
3377                             } finally {
3378                                 this.resultInfo = prevResult;
3379                             }
3380                         });
3381             } else {
3382                 if (isDiamond && clazztype.hasTag(CLASS)) {
3383                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
3384                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
3385                         // One or more types inferred in the previous steps is non-denotable.
3386                         Fragment fragment = Diamond(clazztype.tsym);
3387                         log.error(tree.clazz.pos(),
3388                                 Errors.CantApplyDiamond1(
3389                                         fragment,
3390                                         invalidDiamondArgs.size() > 1 ?
3391                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
3392                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
3393                     }
3394                     // For <>(){}, inferred types must also be accessible.
3395                     for (Type t : clazztype.getTypeArguments()) {
3396                         rs.checkAccessibleType(env, t);
3397                     }
3398                 }
3399 
3400                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
3401                 // false for isInterface call even when the original type is an interface.
3402                 boolean implementing = clazztype.tsym.isInterface() ||
3403                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
3404                         clazztype.getOriginalType().tsym.isInterface();
3405 
3406                 if (implementing) {
3407                     cdef.implementing = List.of(clazz);
3408                 } else {
3409                     cdef.extending = clazz;
3410                 }
3411 
3412                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3413                     rs.isSerializable(clazztype)) {
3414                     localEnv.info.isSerializable = true;
3415                 }
3416 
3417                 attribStat(cdef, localEnv);
3418 
3419                 List<Type> finalargtypes;
3420                 // If an outer instance is given,
3421                 // prefix it to the constructor arguments
3422                 // and delete it from the new expression
3423                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
3424                     finalargtypes = argtypes.prepend(tree.encl.type);
3425                 } else {
3426                     finalargtypes = argtypes;
3427                 }
3428 
3429                 // Reassign clazztype and recompute constructor. As this necessarily involves
3430                 // another attribution pass for deferred types in the case of <>, replicate
3431                 // them. Original arguments have right decorations already.
3432                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3433                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3434                 }
3435 
3436                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3437                                                     : cdef.sym.type;
3438                 Symbol sym = tree.constructor = rs.resolveConstructor(
3439                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3440                 Assert.check(!sym.kind.isResolutionError());
3441                 tree.constructor = sym;
3442                 tree.constructorType = checkId(tree,
3443                         clazztype,
3444                         tree.constructor,
3445                         localEnv,
3446                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3447             }
3448             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3449                                 clazztype : types.createErrorType(tree.type);
3450             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3451             chk.validate(tree.typeargs, localEnv);
3452         }
3453 
3454         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3455             return new Check.NestedCheckContext(checkContext) {
3456                 @Override
3457                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3458                     enclosingContext.report(clazz.clazz,
3459                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3460                 }
3461             };
3462         }
3463 
3464         void checkNewInnerClass(DiagnosticPosition pos, Env<AttrContext> env, Type type, boolean isSuper) {
3465             boolean isLocal = type.tsym.owner.kind == VAR || type.tsym.owner.kind == MTH;
3466             if ((type.tsym.flags() & (INTERFACE | ENUM | RECORD)) != 0 ||
3467                     (!isLocal && !type.tsym.isInner()) ||
3468                     (isSuper && env.enclClass.sym.isAnonymous())) {
3469                 // nothing to check
3470                 return;
3471             }
3472             Symbol res = isLocal ?
3473                     rs.findLocalClassOwner(env, type.tsym) :
3474                     rs.findSelfContaining(pos, env, type.getEnclosingType().tsym, isSuper);
3475             if (res.exists()) {
3476                 rs.accessBase(res, pos, env.enclClass.sym.type, names._this, true);
3477             } else {
3478                 log.error(pos, Errors.EnclClassRequired(type.tsym));
3479             }
3480         }
3481 
3482     /** Make an attributed null check tree.
3483      */
3484     public JCExpression makeNullCheck(JCExpression arg) {
3485         // optimization: new Outer() can never be null; skip null check
3486         if (arg.getTag() == NEWCLASS)
3487             return arg;
3488         // optimization: X.this is never null; skip null check
3489         Name name = TreeInfo.name(arg);
3490         if (name == names._this || name == names._super) return arg;
3491 
3492         JCTree.Tag optag = NULLCHK;
3493         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3494         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3495         tree.type = arg.type;
3496         return tree;
3497     }
3498 
3499     public void visitNewArray(JCNewArray tree) {
3500         Type owntype = types.createErrorType(tree.type);
3501         Env<AttrContext> localEnv = env.dup(tree);
3502         Type elemtype;
3503         if (tree.elemtype != null) {
3504             elemtype = attribType(tree.elemtype, localEnv);
3505             chk.validate(tree.elemtype, localEnv);
3506             owntype = elemtype;
3507             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3508                 attribExpr(l.head, localEnv, syms.intType);
3509                 owntype = new ArrayType(owntype, syms.arrayClass);
3510             }
3511         } else {
3512             // we are seeing an untyped aggregate { ... }
3513             // this is allowed only if the prototype is an array
3514             if (pt().hasTag(ARRAY)) {
3515                 elemtype = types.elemtype(pt());
3516             } else {
3517                 if (!pt().hasTag(ERROR) &&
3518                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3519                     log.error(tree.pos(),
3520                               Errors.IllegalInitializerForType(pt()));
3521                 }
3522                 elemtype = types.createErrorType(pt());
3523             }
3524         }
3525         if (tree.elems != null) {
3526             attribExprs(tree.elems, localEnv, elemtype);
3527             owntype = new ArrayType(elemtype, syms.arrayClass);
3528         }
3529         if (!types.isReifiable(elemtype))
3530             log.error(tree.pos(), Errors.GenericArrayCreation);
3531         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3532     }
3533 
3534     /*
3535      * A lambda expression can only be attributed when a target-type is available.
3536      * In addition, if the target-type is that of a functional interface whose
3537      * descriptor contains inference variables in argument position the lambda expression
3538      * is 'stuck' (see DeferredAttr).
3539      */
3540     @Override
3541     public void visitLambda(final JCLambda that) {
3542         boolean wrongContext = false;
3543         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3544             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3545                 //lambda only allowed in assignment or method invocation/cast context
3546                 log.error(that.pos(), Errors.UnexpectedLambda);
3547             }
3548             resultInfo = recoveryInfo;
3549             wrongContext = true;
3550         }
3551         //create an environment for attribution of the lambda expression
3552         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3553         boolean needsRecovery =
3554                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3555         try {
3556             if (needsRecovery && rs.isSerializable(pt())) {
3557                 localEnv.info.isSerializable = true;
3558                 localEnv.info.isSerializableLambda = true;
3559             }
3560             List<Type> explicitParamTypes = null;
3561             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3562                 //attribute lambda parameters
3563                 attribStats(that.params, localEnv);
3564                 explicitParamTypes = TreeInfo.types(that.params);
3565             }
3566 
3567             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3568             Type currentTarget = targetInfo.target;
3569             Type lambdaType = targetInfo.descriptor;
3570 
3571             if (currentTarget.isErroneous()) {
3572                 result = that.type = currentTarget;
3573                 return;
3574             }
3575 
3576             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3577 
3578             if (lambdaType.hasTag(FORALL)) {
3579                 //lambda expression target desc cannot be a generic method
3580                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3581                                                                     kindName(currentTarget.tsym),
3582                                                                     currentTarget.tsym);
3583                 resultInfo.checkContext.report(that, diags.fragment(msg));
3584                 result = that.type = types.createErrorType(pt());
3585                 return;
3586             }
3587 
3588             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3589                 //add param type info in the AST
3590                 List<Type> actuals = lambdaType.getParameterTypes();
3591                 List<JCVariableDecl> params = that.params;
3592 
3593                 boolean arityMismatch = false;
3594 
3595                 while (params.nonEmpty()) {
3596                     if (actuals.isEmpty()) {
3597                         //not enough actuals to perform lambda parameter inference
3598                         arityMismatch = true;
3599                     }
3600                     //reset previously set info
3601                     Type argType = arityMismatch ?
3602                             syms.errType :
3603                             actuals.head;
3604                     if (params.head.isImplicitlyTyped()) {
3605                         setSyntheticVariableType(params.head, argType);
3606                     }
3607                     params.head.sym = null;
3608                     actuals = actuals.isEmpty() ?
3609                             actuals :
3610                             actuals.tail;
3611                     params = params.tail;
3612                 }
3613 
3614                 //attribute lambda parameters
3615                 attribStats(that.params, localEnv);
3616 
3617                 if (arityMismatch) {
3618                     resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3619                         result = that.type = types.createErrorType(currentTarget);
3620                         return;
3621                 }
3622             }
3623 
3624             //from this point on, no recovery is needed; if we are in assignment context
3625             //we will be able to attribute the whole lambda body, regardless of errors;
3626             //if we are in a 'check' method context, and the lambda is not compatible
3627             //with the target-type, it will be recovered anyway in Attr.checkId
3628             needsRecovery = false;
3629 
3630             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3631                     lambdaBodyResult(that, lambdaType, resultInfo);
3632 
3633             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3634                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3635             } else {
3636                 JCBlock body = (JCBlock)that.body;
3637                 if (body == breakTree &&
3638                         resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3639                     breakTreeFound(copyEnv(localEnv));
3640                 }
3641                 attribStats(body.stats, localEnv);
3642             }
3643 
3644             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3645 
3646             boolean isSpeculativeRound =
3647                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3648 
3649             preFlow(that);
3650             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3651 
3652             that.type = currentTarget; //avoids recovery at this stage
3653             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
3654 
3655             if (!isSpeculativeRound) {
3656                 //add thrown types as bounds to the thrown types free variables if needed:
3657                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3658                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3659                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3660                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3661                     }
3662                 }
3663 
3664                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3665             }
3666             result = wrongContext ? that.type = types.createErrorType(pt())
3667                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3668         } catch (Types.FunctionDescriptorLookupError ex) {
3669             JCDiagnostic cause = ex.getDiagnostic();
3670             resultInfo.checkContext.report(that, cause);
3671             result = that.type = types.createErrorType(pt());
3672             return;
3673         } catch (CompletionFailure cf) {
3674             chk.completionError(that.pos(), cf);
3675         } catch (Throwable t) {
3676             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3677             //as that would likely cause the same exception again.
3678             needsRecovery = false;
3679             throw t;
3680         } finally {
3681             localEnv.info.scope.leave();
3682             if (needsRecovery) {
3683                 Type prevResult = result;
3684                 try {
3685                     attribTree(that, env, recoveryInfo);
3686                 } finally {
3687                     if (result == Type.recoveryType) {
3688                         result = prevResult;
3689                     }
3690                 }
3691             }
3692         }
3693     }
3694     //where
3695         class TargetInfo {
3696             Type target;
3697             Type descriptor;
3698 
3699             public TargetInfo(Type target, Type descriptor) {
3700                 this.target = target;
3701                 this.descriptor = descriptor;
3702             }
3703         }
3704 
3705         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3706             Type lambdaType;
3707             Type currentTarget = resultInfo.pt;
3708             if (resultInfo.pt != Type.recoveryType) {
3709                 /* We need to adjust the target. If the target is an
3710                  * intersection type, for example: SAM & I1 & I2 ...
3711                  * the target will be updated to SAM
3712                  */
3713                 currentTarget = targetChecker.visit(currentTarget, that);
3714                 if (!currentTarget.isIntersection()) {
3715                     if (explicitParamTypes != null) {
3716                         currentTarget = infer.instantiateFunctionalInterface(that,
3717                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3718                     }
3719                     currentTarget = types.removeWildcards(currentTarget);
3720                     lambdaType = types.findDescriptorType(currentTarget);
3721                 } else {
3722                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3723                     ListBuffer<Type> components = new ListBuffer<>();
3724                     for (Type bound : ict.getExplicitComponents()) {
3725                         if (explicitParamTypes != null) {
3726                             try {
3727                                 bound = infer.instantiateFunctionalInterface(that,
3728                                         bound, explicitParamTypes, resultInfo.checkContext);
3729                             } catch (FunctionDescriptorLookupError t) {
3730                                 // do nothing
3731                             }
3732                         }
3733                         if (bound.tsym != syms.objectType.tsym && (!bound.isInterface() || (bound.tsym.flags() & ANNOTATION) != 0)) {
3734                             // bound must be j.l.Object or an interface, but not an annotation
3735                             reportIntersectionError(that, "not.an.intf.component", bound);
3736                         }
3737                         bound = types.removeWildcards(bound);
3738                         components.add(bound);
3739                     }
3740                     currentTarget = types.makeIntersectionType(components.toList());
3741                     currentTarget.tsym.flags_field |= INTERFACE;
3742                     lambdaType = types.findDescriptorType(currentTarget);
3743                 }
3744 
3745             } else {
3746                 currentTarget = Type.recoveryType;
3747                 lambdaType = fallbackDescriptorType(that);
3748             }
3749             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3750                 //lambda expression target desc cannot be a generic method
3751                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3752                                                                     kindName(currentTarget.tsym),
3753                                                                     currentTarget.tsym);
3754                 resultInfo.checkContext.report(that, diags.fragment(msg));
3755                 currentTarget = types.createErrorType(pt());
3756             }
3757             return new TargetInfo(currentTarget, lambdaType);
3758         }
3759 
3760         private void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) {
3761              resultInfo.checkContext.report(pos,
3762                  diags.fragment(Fragments.BadIntersectionTargetForFunctionalExpr(diags.fragment(key, args))));
3763         }
3764 
3765         void preFlow(JCLambda tree) {
3766             attrRecover.doRecovery();
3767             new PostAttrAnalyzer() {
3768                 @Override
3769                 public void scan(JCTree tree) {
3770                     if (tree == null ||
3771                             (tree.type != null &&
3772                             tree.type == Type.stuckType)) {
3773                         //don't touch stuck expressions!
3774                         return;
3775                     }
3776                     super.scan(tree);
3777                 }
3778 
3779                 @Override
3780                 public void visitClassDef(JCClassDecl that) {
3781                     // or class declaration trees!
3782                 }
3783 
3784                 public void visitLambda(JCLambda that) {
3785                     // or lambda expressions!
3786                 }
3787             }.scan(tree.body);
3788         }
3789 
3790         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3791 
3792             @Override
3793             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3794                 return t.isIntersection() ?
3795                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3796             }
3797 
3798             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3799                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3800                 return ict;
3801             }
3802 
3803             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3804                 ListBuffer<Type> targs = new ListBuffer<>();
3805                 ListBuffer<Type> supertypes = new ListBuffer<>();
3806                 for (Type i : ict.interfaces_field) {
3807                     if (i.isParameterized()) {
3808                         targs.appendList(i.tsym.type.allparams());
3809                     }
3810                     supertypes.append(i.tsym.type);
3811                 }
3812                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3813                 notionalIntf.allparams_field = targs.toList();
3814                 notionalIntf.tsym.flags_field |= INTERFACE;
3815                 return notionalIntf.tsym;
3816             }
3817         };
3818 
3819         private Type fallbackDescriptorType(JCExpression tree) {
3820             switch (tree.getTag()) {
3821                 case LAMBDA:
3822                     JCLambda lambda = (JCLambda)tree;
3823                     List<Type> argtypes = List.nil();
3824                     for (JCVariableDecl param : lambda.params) {
3825                         argtypes = param.vartype != null && param.vartype.type != null ?
3826                                 argtypes.append(param.vartype.type) :
3827                                 argtypes.append(syms.errType);
3828                     }
3829                     return new MethodType(argtypes, Type.recoveryType,
3830                             List.of(syms.throwableType), syms.methodClass);
3831                 case REFERENCE:
3832                     return new MethodType(List.nil(), Type.recoveryType,
3833                             List.of(syms.throwableType), syms.methodClass);
3834                 default:
3835                     Assert.error("Cannot get here!");
3836             }
3837             return null;
3838         }
3839 
3840         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3841                 final InferenceContext inferenceContext, final Type... ts) {
3842             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3843         }
3844 
3845         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3846                 final InferenceContext inferenceContext, final List<Type> ts) {
3847             if (inferenceContext.free(ts)) {
3848                 inferenceContext.addFreeTypeListener(ts,
3849                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3850             } else {
3851                 for (Type t : ts) {
3852                     rs.checkAccessibleType(env, t);
3853                 }
3854             }
3855         }
3856 
3857         /**
3858          * Lambda/method reference have a special check context that ensures
3859          * that i.e. a lambda return type is compatible with the expected
3860          * type according to both the inherited context and the assignment
3861          * context.
3862          */
3863         class FunctionalReturnContext extends Check.NestedCheckContext {
3864 
3865             FunctionalReturnContext(CheckContext enclosingContext) {
3866                 super(enclosingContext);
3867             }
3868 
3869             @Override
3870             public boolean compatible(Type found, Type req, Warner warn) {
3871                 //return type must be compatible in both current context and assignment context
3872                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3873             }
3874 
3875             @Override
3876             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3877                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3878             }
3879         }
3880 
3881         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3882 
3883             JCExpression expr;
3884             boolean expStmtExpected;
3885 
3886             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3887                 super(enclosingContext);
3888                 this.expr = expr;
3889             }
3890 
3891             @Override
3892             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3893                 if (expStmtExpected) {
3894                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3895                 } else {
3896                     super.report(pos, details);
3897                 }
3898             }
3899 
3900             @Override
3901             public boolean compatible(Type found, Type req, Warner warn) {
3902                 //a void return is compatible with an expression statement lambda
3903                 if (req.hasTag(VOID)) {
3904                     expStmtExpected = true;
3905                     return TreeInfo.isExpressionStatement(expr);
3906                 } else {
3907                     return super.compatible(found, req, warn);
3908                 }
3909             }
3910         }
3911 
3912         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3913             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3914                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3915                     new FunctionalReturnContext(resultInfo.checkContext);
3916 
3917             return descriptor.getReturnType() == Type.recoveryType ?
3918                     recoveryInfo :
3919                     new ResultInfo(KindSelector.VAL,
3920                             descriptor.getReturnType(), funcContext);
3921         }
3922 
3923         /**
3924         * Lambda compatibility. Check that given return types, thrown types, parameter types
3925         * are compatible with the expected functional interface descriptor. This means that:
3926         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3927         * types must be compatible with the return type of the expected descriptor.
3928         */
3929         void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
3930             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3931 
3932             //return values have already been checked - but if lambda has no return
3933             //values, we must ensure that void/value compatibility is correct;
3934             //this amounts at checking that, if a lambda body can complete normally,
3935             //the descriptor's return type must be void
3936             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3937                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3938                 Fragment msg =
3939                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3940                 checkContext.report(tree,
3941                                     diags.fragment(msg));
3942             }
3943 
3944             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3945             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3946                 checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3947             }
3948         }
3949 
3950         /* This method returns an environment to be used to attribute a lambda
3951          * expression.
3952          *
3953          * The owner of this environment is a method symbol. If the current owner
3954          * is not a method (e.g. if the lambda occurs in a field initializer), then
3955          * a synthetic method symbol owner is created.
3956          */
3957         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3958             Env<AttrContext> lambdaEnv;
3959             Symbol owner = env.info.scope.owner;
3960             if (owner.kind == VAR && owner.owner.kind == TYP) {
3961                 // If the lambda is nested in a field initializer, we need to create a fake init method.
3962                 // Uniqueness of this symbol is not important (as e.g. annotations will be added on the
3963                 // init symbol's owner).
3964                 ClassSymbol enclClass = owner.enclClass();
3965                 Name initName = owner.isStatic() ? names.clinit : names.init;
3966                 MethodSymbol initSym = new MethodSymbol(BLOCK | (owner.isStatic() ? STATIC : 0) | SYNTHETIC | PRIVATE,
3967                         initName, initBlockType, enclClass);
3968                 initSym.params = List.nil();
3969                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(initSym)));
3970             } else {
3971                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3972             }
3973             lambdaEnv.info.yieldResult = null;
3974             lambdaEnv.info.isLambda = true;
3975             return lambdaEnv;
3976         }
3977 
3978     @Override
3979     public void visitReference(final JCMemberReference that) {
3980         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3981             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3982                 //method reference only allowed in assignment or method invocation/cast context
3983                 log.error(that.pos(), Errors.UnexpectedMref);
3984             }
3985             result = that.type = types.createErrorType(pt());
3986             return;
3987         }
3988         final Env<AttrContext> localEnv = env.dup(that);
3989         try {
3990             //attribute member reference qualifier - if this is a constructor
3991             //reference, the expected kind must be a type
3992             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3993 
3994             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3995                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3996                 if (!exprType.isErroneous() &&
3997                     exprType.isRaw() &&
3998                     that.typeargs != null) {
3999                     log.error(that.expr.pos(),
4000                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
4001                                                  Fragments.MrefInferAndExplicitParams));
4002                     exprType = types.createErrorType(exprType);
4003                 }
4004             }
4005 
4006             if (exprType.isErroneous()) {
4007                 //if the qualifier expression contains problems,
4008                 //give up attribution of method reference
4009                 result = that.type = exprType;
4010                 return;
4011             }
4012 
4013             if (TreeInfo.isStaticSelector(that.expr, names)) {
4014                 //if the qualifier is a type, validate it; raw warning check is
4015                 //omitted as we don't know at this stage as to whether this is a
4016                 //raw selector (because of inference)
4017                 chk.validate(that.expr, env, false);
4018             } else {
4019                 Symbol lhsSym = TreeInfo.symbol(that.expr);
4020                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
4021             }
4022             //attrib type-arguments
4023             List<Type> typeargtypes = List.nil();
4024             if (that.typeargs != null) {
4025                 typeargtypes = attribTypes(that.typeargs, localEnv);
4026             }
4027 
4028             boolean isTargetSerializable =
4029                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
4030                     rs.isSerializable(pt());
4031             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
4032             Type currentTarget = targetInfo.target;
4033             Type desc = targetInfo.descriptor;
4034 
4035             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
4036             List<Type> argtypes = desc.getParameterTypes();
4037             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
4038 
4039             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
4040                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
4041             }
4042 
4043             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
4044             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
4045             try {
4046                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
4047                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
4048                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
4049             } finally {
4050                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
4051             }
4052 
4053             Symbol refSym = refResult.fst;
4054             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
4055 
4056             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
4057              *  JDK-8075541
4058              */
4059             if (refSym.kind != MTH) {
4060                 boolean targetError;
4061                 switch (refSym.kind) {
4062                     case ABSENT_MTH:
4063                         targetError = false;
4064                         break;
4065                     case WRONG_MTH:
4066                     case WRONG_MTHS:
4067                     case AMBIGUOUS:
4068                     case HIDDEN:
4069                     case STATICERR:
4070                         targetError = true;
4071                         break;
4072                     default:
4073                         Assert.error("unexpected result kind " + refSym.kind);
4074                         targetError = false;
4075                 }
4076 
4077                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
4078                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
4079                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
4080 
4081                 JCDiagnostic diag = diags.create(log.currentSource(), that,
4082                         targetError ?
4083                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
4084                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
4085 
4086                 if (targetError && currentTarget == Type.recoveryType) {
4087                     //a target error doesn't make sense during recovery stage
4088                     //as we don't know what actual parameter types are
4089                     result = that.type = currentTarget;
4090                     return;
4091                 } else {
4092                     if (targetError) {
4093                         resultInfo.checkContext.report(that, diag);
4094                     } else {
4095                         log.report(diag);
4096                     }
4097                     result = that.type = types.createErrorType(currentTarget);
4098                     return;
4099                 }
4100             }
4101 
4102             that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
4103             that.kind = lookupHelper.referenceKind(that.sym);
4104             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
4105 
4106             if (desc.getReturnType() == Type.recoveryType) {
4107                 // stop here
4108                 result = that.type = currentTarget;
4109                 return;
4110             }
4111 
4112             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
4113                 checkNewInnerClass(that.pos(), env, exprType, false);
4114             }
4115 
4116             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
4117 
4118                 if (that.getMode() == ReferenceMode.INVOKE &&
4119                         TreeInfo.isStaticSelector(that.expr, names) &&
4120                         that.kind.isUnbound() &&
4121                         lookupHelper.site.isRaw()) {
4122                     chk.checkRaw(that.expr, localEnv);
4123                 }
4124 
4125                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
4126                         exprType.getTypeArguments().nonEmpty()) {
4127                     //static ref with class type-args
4128                     log.error(that.expr.pos(),
4129                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
4130                                                  Fragments.StaticMrefWithTargs));
4131                     result = that.type = types.createErrorType(currentTarget);
4132                     return;
4133                 }
4134 
4135                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
4136                     // Check that super-qualified symbols are not abstract (JLS)
4137                     rs.checkNonAbstract(that.pos(), that.sym);
4138                 }
4139 
4140                 if (isTargetSerializable) {
4141                     chk.checkAccessFromSerializableElement(that, true);
4142                 }
4143             }
4144 
4145             ResultInfo checkInfo =
4146                     resultInfo.dup(newMethodTemplate(
4147                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
4148                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
4149                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
4150 
4151             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
4152 
4153             if (that.kind.isUnbound() &&
4154                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
4155                 //re-generate inference constraints for unbound receiver
4156                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
4157                     //cannot happen as this has already been checked - we just need
4158                     //to regenerate the inference constraints, as that has been lost
4159                     //as a result of the call to inferenceContext.save()
4160                     Assert.error("Can't get here");
4161                 }
4162             }
4163 
4164             if (!refType.isErroneous()) {
4165                 refType = types.createMethodTypeWithReturn(refType,
4166                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
4167             }
4168 
4169             //go ahead with standard method reference compatibility check - note that param check
4170             //is a no-op (as this has been taken care during method applicability)
4171             boolean isSpeculativeRound =
4172                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
4173 
4174             that.type = currentTarget; //avoids recovery at this stage
4175             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
4176             if (!isSpeculativeRound) {
4177                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
4178             }
4179             chk.checkRequiresIdentity(that, localEnv.info.lint);
4180             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
4181         } catch (Types.FunctionDescriptorLookupError ex) {
4182             JCDiagnostic cause = ex.getDiagnostic();
4183             resultInfo.checkContext.report(that, cause);
4184             result = that.type = types.createErrorType(pt());
4185             return;
4186         }
4187     }
4188     //where
4189         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
4190             //if this is a constructor reference, the expected kind must be a type
4191             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
4192                                   KindSelector.VAL_TYP : KindSelector.TYP,
4193                                   Type.noType);
4194         }
4195 
4196 
4197     @SuppressWarnings("fallthrough")
4198     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
4199         InferenceContext inferenceContext = checkContext.inferenceContext();
4200         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
4201 
4202         Type resType;
4203         switch (tree.getMode()) {
4204             case NEW:
4205                 if (!tree.expr.type.isRaw()) {
4206                     resType = tree.expr.type;
4207                     break;
4208                 }
4209             default:
4210                 resType = refType.getReturnType();
4211         }
4212 
4213         Type incompatibleReturnType = resType;
4214 
4215         if (returnType.hasTag(VOID)) {
4216             incompatibleReturnType = null;
4217         }
4218 
4219         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
4220             Type capturedResType = captureMRefReturnType ? types.capture(resType) : resType;
4221             if (resType.isErroneous() ||
4222                     new FunctionalReturnContext(checkContext).compatible(capturedResType, returnType,
4223                             checkContext.checkWarner(tree, capturedResType, returnType))) {
4224                 incompatibleReturnType = null;
4225             }
4226         }
4227 
4228         if (incompatibleReturnType != null) {
4229             Fragment msg =
4230                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
4231             checkContext.report(tree, diags.fragment(msg));
4232         } else {
4233             if (inferenceContext.free(refType)) {
4234                 // we need to wait for inference to finish and then replace inference vars in the referent type
4235                 inferenceContext.addFreeTypeListener(List.of(refType),
4236                         instantiatedContext -> {
4237                             tree.referentType = instantiatedContext.asInstType(refType);
4238                         });
4239             } else {
4240                 tree.referentType = refType;
4241             }
4242         }
4243 
4244         if (!speculativeAttr) {
4245             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
4246                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
4247             }
4248         }
4249     }
4250 
4251     boolean checkExConstraints(
4252             List<Type> thrownByFuncExpr,
4253             List<Type> thrownAtFuncType,
4254             InferenceContext inferenceContext) {
4255         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
4256          *  are not proper types
4257          */
4258         List<Type> nonProperList = thrownAtFuncType.stream()
4259                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
4260         List<Type> properList = thrownAtFuncType.diff(nonProperList);
4261 
4262         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
4263          *  in the throws clause of the invocation type of the method reference's compile-time
4264          *  declaration
4265          */
4266         List<Type> checkedList = thrownByFuncExpr.stream()
4267                 .filter(e -> chk.isChecked(e)).collect(List.collector());
4268 
4269         /** If n = 0 (the function type's throws clause consists only of proper types), then
4270          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
4271          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
4272          *  reduces to true
4273          */
4274         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
4275         for (Type checked : checkedList) {
4276             boolean isSubtype = false;
4277             for (Type proper : properList) {
4278                 if (types.isSubtype(checked, proper)) {
4279                     isSubtype = true;
4280                     break;
4281                 }
4282             }
4283             if (!isSubtype) {
4284                 uncaughtByProperTypes.add(checked);
4285             }
4286         }
4287 
4288         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
4289             return false;
4290         }
4291 
4292         /** If n > 0, the constraint reduces to a set of subtyping constraints:
4293          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
4294          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
4295          */
4296         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
4297         uncaughtByProperTypes.forEach(checkedEx -> {
4298             nonProperAsUndet.forEach(nonProper -> {
4299                 types.isSubtype(checkedEx, nonProper);
4300             });
4301         });
4302 
4303         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
4304          */
4305         nonProperAsUndet.stream()
4306                 .filter(t -> t.hasTag(UNDETVAR))
4307                 .forEach(t -> ((UndetVar)t).setThrow());
4308         return true;
4309     }
4310 
4311     /**
4312      * Set functional type info on the underlying AST. Note: as the target descriptor
4313      * might contain inference variables, we might need to register an hook in the
4314      * current inference context.
4315      */
4316     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
4317             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
4318         if (checkContext.inferenceContext().free(descriptorType)) {
4319             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
4320                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
4321                     inferenceContext.asInstType(primaryTarget), checkContext));
4322         } else {
4323             fExpr.owner = env.info.scope.owner;
4324             if (pt.hasTag(CLASS)) {
4325                 fExpr.target = primaryTarget;
4326             }
4327             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
4328                     pt != Type.recoveryType) {
4329                 //check that functional interface class is well-formed
4330                 try {
4331                     /* Types.makeFunctionalInterfaceClass() may throw an exception
4332                      * when it's executed post-inference. See the listener code
4333                      * above.
4334                      */
4335                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
4336                             names.empty, fExpr.target, ABSTRACT);
4337                     if (csym != null) {
4338                         chk.checkImplementations(env.tree, csym, csym);
4339                         try {
4340                             //perform an additional functional interface check on the synthetic class,
4341                             //as there may be spurious errors for raw targets - because of existing issues
4342                             //with membership and inheritance (see JDK-8074570).
4343                             csym.flags_field |= INTERFACE;
4344                             types.findDescriptorType(csym.type);
4345                         } catch (FunctionDescriptorLookupError err) {
4346                             resultInfo.checkContext.report(fExpr,
4347                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
4348                         }
4349                     }
4350                 } catch (Types.FunctionDescriptorLookupError ex) {
4351                     JCDiagnostic cause = ex.getDiagnostic();
4352                     resultInfo.checkContext.report(env.tree, cause);
4353                 }
4354             }
4355         }
4356     }
4357 
4358     public void visitParens(JCParens tree) {
4359         Type owntype = attribTree(tree.expr, env, resultInfo);
4360         result = check(tree, owntype, pkind(), resultInfo);
4361         Symbol sym = TreeInfo.symbol(tree);
4362         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
4363             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
4364     }
4365 
4366     public void visitAssign(JCAssign tree) {
4367         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
4368         Type capturedType = capture(owntype);
4369         attribExpr(tree.rhs, env, owntype);
4370         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
4371     }
4372 
4373     public void visitAssignop(JCAssignOp tree) {
4374         // Attribute arguments.
4375         Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
4376         Type operand = attribExpr(tree.rhs, env);
4377         // Find operator.
4378         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
4379         if (operator != operators.noOpSymbol &&
4380                 !owntype.isErroneous() &&
4381                 !operand.isErroneous()) {
4382             chk.checkDivZero(tree.rhs.pos(), operator, operand);
4383             chk.checkCastable(tree.rhs.pos(),
4384                               operator.type.getReturnType(),
4385                               owntype);
4386             chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
4387         }
4388         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4389     }
4390 
4391     public void visitUnary(JCUnary tree) {
4392         // Attribute arguments.
4393         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
4394             ? attribTree(tree.arg, env, varAssignmentInfo)
4395             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
4396 
4397         // Find operator.
4398         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
4399         Type owntype = types.createErrorType(tree.type);
4400         if (operator != operators.noOpSymbol &&
4401                 !argtype.isErroneous()) {
4402             owntype = (tree.getTag().isIncOrDecUnaryOp())
4403                 ? tree.arg.type
4404                 : operator.type.getReturnType();
4405             int opc = operator.opcode;
4406 
4407             // If the argument is constant, fold it.
4408             if (argtype.constValue() != null) {
4409                 Type ctype = cfolder.fold1(opc, argtype);
4410                 if (ctype != null) {
4411                     owntype = cfolder.coerce(ctype, owntype);
4412                 }
4413             }
4414         }
4415         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4416         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4417     }
4418 
4419     public void visitBinary(JCBinary tree) {
4420         // Attribute arguments.
4421         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4422         // x && y
4423         // include x's bindings when true in y
4424 
4425         // x || y
4426         // include x's bindings when false in y
4427 
4428         MatchBindings lhsBindings = matchBindings;
4429         List<BindingSymbol> propagatedBindings;
4430         switch (tree.getTag()) {
4431             case AND:
4432                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4433                 break;
4434             case OR:
4435                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4436                 break;
4437             default:
4438                 propagatedBindings = List.nil();
4439                 break;
4440         }
4441         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4442         Type right;
4443         try {
4444             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4445         } finally {
4446             rhsEnv.info.scope.leave();
4447         }
4448 
4449         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4450 
4451         // Find operator.
4452         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4453         Type owntype = types.createErrorType(tree.type);
4454         if (operator != operators.noOpSymbol &&
4455                 !left.isErroneous() &&
4456                 !right.isErroneous()) {
4457             owntype = operator.type.getReturnType();
4458             int opc = operator.opcode;
4459             // If both arguments are constants, fold them.
4460             if (left.constValue() != null && right.constValue() != null) {
4461                 Type ctype = cfolder.fold2(opc, left, right);
4462                 if (ctype != null) {
4463                     owntype = cfolder.coerce(ctype, owntype);
4464                 }
4465             }
4466 
4467             // Check that argument types of a reference ==, != are
4468             // castable to each other, (JLS 15.21).  Note: unboxing
4469             // comparisons will not have an acmp* opc at this point.
4470             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4471                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4472                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4473                 }
4474             }
4475 
4476             chk.checkDivZero(tree.rhs.pos(), operator, right);
4477         }
4478         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4479     }
4480 
4481     public void visitTypeCast(final JCTypeCast tree) {
4482         Type clazztype = attribType(tree.clazz, env);
4483         chk.validate(tree.clazz, env, false);
4484         chk.checkRequiresIdentity(tree, env.info.lint);
4485         //a fresh environment is required for 292 inference to work properly ---
4486         //see Infer.instantiatePolymorphicSignatureInstance()
4487         Env<AttrContext> localEnv = env.dup(tree);
4488         //should we propagate the target type?
4489         final ResultInfo castInfo;
4490         JCExpression expr = TreeInfo.skipParens(tree.expr);
4491         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4492         if (isPoly) {
4493             //expression is a poly - we need to propagate target type info
4494             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4495                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4496                 @Override
4497                 public boolean compatible(Type found, Type req, Warner warn) {
4498                     return types.isCastable(found, req, warn);
4499                 }
4500             });
4501         } else {
4502             //standalone cast - target-type info is not propagated
4503             castInfo = unknownExprInfo;
4504         }
4505         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4506         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4507         if (exprtype.constValue() != null)
4508             owntype = cfolder.coerce(exprtype, owntype);
4509         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4510         if (!isPoly)
4511             chk.checkRedundantCast(localEnv, tree);
4512     }
4513 
4514     public void visitTypeTest(JCInstanceOf tree) {
4515         Type exprtype = attribExpr(tree.expr, env);
4516         if (exprtype.isPrimitive()) {
4517             preview.checkSourceLevel(tree.expr.pos(), Feature.PRIMITIVE_PATTERNS);
4518         } else {
4519             exprtype = chk.checkNullOrRefType(
4520                     tree.expr.pos(), exprtype);
4521         }
4522         Type clazztype;
4523         JCTree typeTree;
4524         if (tree.pattern.getTag() == BINDINGPATTERN ||
4525             tree.pattern.getTag() == RECORDPATTERN) {
4526             attribExpr(tree.pattern, env, exprtype);
4527             clazztype = tree.pattern.type;
4528             if (types.isSubtype(exprtype, clazztype) &&
4529                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4530                 tree.pattern.getTag() != RECORDPATTERN) {
4531                 if (!allowUnconditionalPatternsInstanceOf) {
4532                     log.error(tree.pos(), Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.error(this.sourceName));
4533                 }
4534             }
4535             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4536         } else {
4537             clazztype = attribType(tree.pattern, env);
4538             typeTree = tree.pattern;
4539             chk.validate(typeTree, env, false);
4540         }
4541         if (clazztype.isPrimitive()) {
4542             preview.checkSourceLevel(tree.pattern.pos(), Feature.PRIMITIVE_PATTERNS);
4543         } else {
4544             if (!clazztype.hasTag(TYPEVAR)) {
4545                 clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4546             }
4547             if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4548                 boolean valid = false;
4549                 if (allowReifiableTypesInInstanceof) {
4550                     valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4551                 } else {
4552                     log.error(tree.pos(), Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4553                     allowReifiableTypesInInstanceof = true;
4554                 }
4555                 if (!valid) {
4556                     clazztype = types.createErrorType(clazztype);
4557                 }
4558             }
4559         }
4560         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4561         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4562     }
4563 
4564     private boolean checkCastablePattern(DiagnosticPosition pos,
4565                                          Type exprType,
4566                                          Type pattType) {
4567         Warner warner = new Warner();
4568         // if any type is erroneous, the problem is reported elsewhere
4569         if (exprType.isErroneous() || pattType.isErroneous()) {
4570             return false;
4571         }
4572         if (!types.isCastable(exprType, pattType, warner)) {
4573             chk.basicHandler.report(pos,
4574                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4575             return false;
4576         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4577                 (!exprType.isPrimitive() || !pattType.isPrimitive() || !types.isSameType(exprType, pattType))) {
4578             preview.checkSourceLevel(pos, Feature.PRIMITIVE_PATTERNS);
4579             return true;
4580         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4581             log.error(pos,
4582                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4583             return false;
4584         } else {
4585             return true;
4586         }
4587     }
4588 
4589     @Override
4590     public void visitAnyPattern(JCAnyPattern tree) {
4591         result = tree.type = resultInfo.pt;
4592     }
4593 
4594     public void visitBindingPattern(JCBindingPattern tree) {
4595         Type type;
4596         if (tree.var.vartype != null) {
4597             type = attribType(tree.var.vartype, env);
4598         } else {
4599             type = resultInfo.pt;
4600         }
4601         tree.type = tree.var.type = type;
4602         BindingSymbol v = new BindingSymbol(tree.var.mods.flags, tree.var.name, type, env.info.scope.owner);
4603         v.pos = tree.pos;
4604         tree.var.sym = v;
4605         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4606             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4607         }
4608         chk.validate(tree.var.vartype, env, true);
4609         if (tree.var.isImplicitlyTyped()) {
4610             setSyntheticVariableType(tree.var, type == Type.noType ? syms.errType
4611                                                                    : type);
4612         }
4613         annotate.annotateLater(tree.var.mods.annotations, env, v);
4614         if (!tree.var.isImplicitlyTyped()) {
4615             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v);
4616         }
4617         annotate.flush();
4618         result = tree.type;
4619         if (v.isUnnamedVariable()) {
4620             matchBindings = MatchBindingsComputer.EMPTY;
4621         } else {
4622             matchBindings = new MatchBindings(List.of(v), List.nil());
4623         }
4624         chk.checkRequiresIdentity(tree, env.info.lint);
4625     }
4626 
4627     @Override
4628     public void visitRecordPattern(JCRecordPattern tree) {
4629         Type site;
4630 
4631         if (tree.deconstructor == null) {
4632             log.error(tree.pos(), Errors.DeconstructionPatternVarNotAllowed);
4633             tree.record = syms.errSymbol;
4634             site = tree.type = types.createErrorType(tree.record.type);
4635         } else {
4636             Type type = attribType(tree.deconstructor, env);
4637             if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4638                 Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4639                 if (inferred == null) {
4640                     log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4641                 } else {
4642                     type = inferred;
4643                 }
4644             }
4645             tree.type = tree.deconstructor.type = type;
4646             site = types.capture(tree.type);
4647         }
4648 
4649         List<Type> expectedRecordTypes;
4650         if (site.tsym.kind == Kind.TYP && ((ClassSymbol) site.tsym).isRecord()) {
4651             ClassSymbol record = (ClassSymbol) site.tsym;
4652             expectedRecordTypes = record.getRecordComponents()
4653                                         .stream()
4654                                         .map(rc -> types.memberType(site, rc))
4655                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4656                                         .collect(List.collector());
4657             tree.record = record;
4658         } else {
4659             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4660             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4661                                 .limit(tree.nested.size())
4662                                 .collect(List.collector());
4663             tree.record = syms.errSymbol;
4664         }
4665         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4666         List<Type> recordTypes = expectedRecordTypes;
4667         List<JCPattern> nestedPatterns = tree.nested;
4668         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4669         try {
4670             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4671                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4672                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4673                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4674                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4675                 nestedPatterns = nestedPatterns.tail;
4676                 recordTypes = recordTypes.tail;
4677             }
4678             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4679                 while (nestedPatterns.nonEmpty()) {
4680                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4681                     nestedPatterns = nestedPatterns.tail;
4682                 }
4683                 List<Type> nestedTypes =
4684                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4685                 log.error(tree.pos(),
4686                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4687                                                                  nestedTypes));
4688             }
4689         } finally {
4690             localEnv.info.scope.leave();
4691         }
4692         chk.validate(tree.deconstructor, env, true);
4693         result = tree.type;
4694         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4695     }
4696 
4697     public void visitIndexed(JCArrayAccess tree) {
4698         Type owntype = types.createErrorType(tree.type);
4699         Type atype = attribExpr(tree.indexed, env);
4700         attribExpr(tree.index, env, syms.intType);
4701         if (types.isArray(atype))
4702             owntype = types.elemtype(atype);
4703         else if (!atype.hasTag(ERROR))
4704             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4705         if (!pkind().contains(KindSelector.VAL))
4706             owntype = capture(owntype);
4707         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4708     }
4709 
4710     public void visitIdent(JCIdent tree) {
4711         Symbol sym;
4712 
4713         // Find symbol
4714         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4715             // If we are looking for a method, the prototype `pt' will be a
4716             // method type with the type of the call's arguments as parameters.
4717             env.info.pendingResolutionPhase = null;
4718             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4719         } else if (tree.sym != null && tree.sym.kind != VAR) {
4720             sym = tree.sym;
4721         } else {
4722             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4723         }
4724         tree.sym = sym;
4725 
4726         // Also find the environment current for the class where
4727         // sym is defined (`symEnv').
4728         Env<AttrContext> symEnv = env;
4729         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4730             sym.kind.matches(KindSelector.VAL_MTH) &&
4731             sym.owner.kind == TYP &&
4732             tree.name != names._this && tree.name != names._super) {
4733 
4734             // Find environment in which identifier is defined.
4735             while (symEnv.outer != null &&
4736                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4737                 symEnv = symEnv.outer;
4738             }
4739         }
4740 
4741         // If symbol is a variable, ...
4742         if (sym.kind == VAR) {
4743             VarSymbol v = (VarSymbol)sym;
4744 
4745             // ..., evaluate its initializer, if it has one, and check for
4746             // illegal forward reference.
4747             checkInit(tree, env, v, false);
4748 
4749             // If we are expecting a variable (as opposed to a value), check
4750             // that the variable is assignable in the current environment.
4751             if (KindSelector.ASG.subset(pkind()))
4752                 checkAssignable(tree.pos(), v, null, env);
4753         }
4754 
4755         Env<AttrContext> env1 = env;
4756         if (sym.kind != ERR && sym.kind != TYP &&
4757             sym.owner != null && sym.owner != env1.enclClass.sym) {
4758             // If the found symbol is inaccessible, then it is
4759             // accessed through an enclosing instance.  Locate this
4760             // enclosing instance:
4761             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4762                 env1 = env1.outer;
4763         }
4764 
4765         if (env.info.isSerializable) {
4766             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4767         }
4768 
4769         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4770     }
4771 
4772     public void visitSelect(JCFieldAccess tree) {
4773         // Determine the expected kind of the qualifier expression.
4774         KindSelector skind = KindSelector.NIL;
4775         if (tree.name == names._this || tree.name == names._super ||
4776                 tree.name == names._class)
4777         {
4778             skind = KindSelector.TYP;
4779         } else {
4780             if (pkind().contains(KindSelector.PCK))
4781                 skind = KindSelector.of(skind, KindSelector.PCK);
4782             if (pkind().contains(KindSelector.TYP))
4783                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4784             if (pkind().contains(KindSelector.VAL_MTH))
4785                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4786         }
4787 
4788         // Attribute the qualifier expression, and determine its symbol (if any).
4789         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
4790         Assert.check(site == tree.selected.type);
4791         if (!pkind().contains(KindSelector.TYP_PCK))
4792             site = capture(site); // Capture field access
4793 
4794         // don't allow T.class T[].class, etc
4795         if (skind == KindSelector.TYP) {
4796             Type elt = site;
4797             while (elt.hasTag(ARRAY))
4798                 elt = ((ArrayType)elt).elemtype;
4799             if (elt.hasTag(TYPEVAR)) {
4800                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4801                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4802                 tree.sym = tree.type.tsym;
4803                 return ;
4804             }
4805         }
4806 
4807         // If qualifier symbol is a type or `super', assert `selectSuper'
4808         // for the selection. This is relevant for determining whether
4809         // protected symbols are accessible.
4810         Symbol sitesym = TreeInfo.symbol(tree.selected);
4811         boolean selectSuperPrev = env.info.selectSuper;
4812         env.info.selectSuper =
4813             sitesym != null &&
4814             sitesym.name == names._super;
4815 
4816         // Determine the symbol represented by the selection.
4817         env.info.pendingResolutionPhase = null;
4818         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
4819         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4820             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4821             sym = syms.errSymbol;
4822         }
4823         if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
4824             site = capture(site);
4825             sym = selectSym(tree, sitesym, site, env, resultInfo);
4826         }
4827         boolean varArgs = env.info.lastResolveVarargs();
4828         tree.sym = sym;
4829 
4830         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4831             site = types.skipTypeVars(site, true);
4832         }
4833 
4834         // If that symbol is a variable, ...
4835         if (sym.kind == VAR) {
4836             VarSymbol v = (VarSymbol)sym;
4837 
4838             // ..., evaluate its initializer, if it has one, and check for
4839             // illegal forward reference.
4840             checkInit(tree, env, v, true);
4841 
4842             // If we are expecting a variable (as opposed to a value), check
4843             // that the variable is assignable in the current environment.
4844             if (KindSelector.ASG.subset(pkind()))
4845                 checkAssignable(tree.pos(), v, tree.selected, env);
4846         }
4847 
4848         if (sitesym != null &&
4849                 sitesym.kind == VAR &&
4850                 ((VarSymbol)sitesym).isResourceVariable() &&
4851                 sym.kind == MTH &&
4852                 sym.name.equals(names.close) &&
4853                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true)) {
4854             log.warning(tree, LintWarnings.TryExplicitCloseCall);
4855         }
4856 
4857         // Disallow selecting a type from an expression
4858         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4859             tree.type = check(tree.selected, pt(),
4860                               sitesym == null ?
4861                                       KindSelector.VAL : sitesym.kind.toSelector(),
4862                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4863         }
4864 
4865         if (isType(sitesym)) {
4866             if (sym.name != names._this && sym.name != names._super) {
4867                 // Check if type-qualified fields or methods are static (JLS)
4868                 if ((sym.flags() & STATIC) == 0 &&
4869                     sym.name != names._super &&
4870                     (sym.kind == VAR || sym.kind == MTH)) {
4871                     rs.accessBase(rs.new StaticError(sym),
4872                               tree.pos(), site, sym.name, true);
4873                 }
4874             }
4875         } else if (sym.kind != ERR &&
4876                    (sym.flags() & STATIC) != 0 &&
4877                    sym.name != names._class) {
4878             // If the qualified item is not a type and the selected item is static, report
4879             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4880             if (!sym.owner.isAnonymous()) {
4881                 log.warning(tree, LintWarnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4882             } else {
4883                 log.warning(tree, LintWarnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4884             }
4885         }
4886 
4887         // If we are selecting an instance member via a `super', ...
4888         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4889 
4890             // Check that super-qualified symbols are not abstract (JLS)
4891             rs.checkNonAbstract(tree.pos(), sym);
4892 
4893             if (site.isRaw()) {
4894                 // Determine argument types for site.
4895                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
4896                 if (site1 != null) site = site1;
4897             }
4898         }
4899 
4900         if (env.info.isSerializable) {
4901             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4902         }
4903 
4904         env.info.selectSuper = selectSuperPrev;
4905         result = checkId(tree, site, sym, env, resultInfo);
4906     }
4907     //where
4908         /** Determine symbol referenced by a Select expression,
4909          *
4910          *  @param tree   The select tree.
4911          *  @param site   The type of the selected expression,
4912          *  @param env    The current environment.
4913          *  @param resultInfo The current result.
4914          */
4915         private Symbol selectSym(JCFieldAccess tree,
4916                                  Symbol location,
4917                                  Type site,
4918                                  Env<AttrContext> env,
4919                                  ResultInfo resultInfo) {
4920             DiagnosticPosition pos = tree.pos();
4921             Name name = tree.name;
4922             switch (site.getTag()) {
4923             case PACKAGE:
4924                 return rs.accessBase(
4925                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4926                     pos, location, site, name, true);
4927             case ARRAY:
4928             case CLASS:
4929                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4930                     return rs.resolveQualifiedMethod(
4931                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4932                 } else if (name == names._this || name == names._super) {
4933                     return rs.resolveSelf(pos, env, site.tsym, tree);
4934                 } else if (name == names._class) {
4935                     // In this case, we have already made sure in
4936                     // visitSelect that qualifier expression is a type.
4937                     return syms.getClassField(site, types);
4938                 } else {
4939                     // We are seeing a plain identifier as selector.
4940                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
4941                         sym = rs.accessBase(sym, pos, location, site, name, true);
4942                     return sym;
4943                 }
4944             case WILDCARD:
4945                 throw new AssertionError(tree);
4946             case TYPEVAR:
4947                 // Normally, site.getUpperBound() shouldn't be null.
4948                 // It should only happen during memberEnter/attribBase
4949                 // when determining the supertype which *must* be
4950                 // done before attributing the type variables.  In
4951                 // other words, we are seeing this illegal program:
4952                 // class B<T> extends A<T.foo> {}
4953                 Symbol sym = (site.getUpperBound() != null)
4954                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
4955                     : null;
4956                 if (sym == null) {
4957                     log.error(pos, Errors.TypeVarCantBeDeref);
4958                     return syms.errSymbol;
4959                 } else {
4960                     // JLS 4.9 specifies the members are derived by inheritance.
4961                     // We skip inducing a whole class by filtering members that
4962                     // can never be inherited:
4963                     Symbol sym2;
4964                     if (sym.isPrivate()) {
4965                         // Private members
4966                         sym2 = rs.new AccessError(env, site, sym);
4967                     } else if (sym.owner.isInterface() && sym.kind == MTH && (sym.flags() & STATIC) != 0) {
4968                         // Interface static methods
4969                         sym2 = rs.new SymbolNotFoundError(ABSENT_MTH);
4970                     } else {
4971                         sym2 = sym;
4972                     }
4973                     rs.accessBase(sym2, pos, location, site, name, true);
4974                     return sym;
4975                 }
4976             case ERROR:
4977                 // preserve identifier names through errors
4978                 return types.createErrorType(name, site.tsym, site).tsym;
4979             default:
4980                 // The qualifier expression is of a primitive type -- only
4981                 // .class is allowed for these.
4982                 if (name == names._class) {
4983                     // In this case, we have already made sure in Select that
4984                     // qualifier expression is a type.
4985                     return syms.getClassField(site, types);
4986                 } else {
4987                     log.error(pos, Errors.CantDeref(site));
4988                     return syms.errSymbol;
4989                 }
4990             }
4991         }
4992 
4993         /** Determine type of identifier or select expression and check that
4994          *  (1) the referenced symbol is not deprecated
4995          *  (2) the symbol's type is safe (@see checkSafe)
4996          *  (3) if symbol is a variable, check that its type and kind are
4997          *      compatible with the prototype and protokind.
4998          *  (4) if symbol is an instance field of a raw type,
4999          *      which is being assigned to, issue an unchecked warning if its
5000          *      type changes under erasure.
5001          *  (5) if symbol is an instance method of a raw type, issue an
5002          *      unchecked warning if its argument types change under erasure.
5003          *  If checks succeed:
5004          *    If symbol is a constant, return its constant type
5005          *    else if symbol is a method, return its result type
5006          *    otherwise return its type.
5007          *  Otherwise return errType.
5008          *
5009          *  @param tree       The syntax tree representing the identifier
5010          *  @param site       If this is a select, the type of the selected
5011          *                    expression, otherwise the type of the current class.
5012          *  @param sym        The symbol representing the identifier.
5013          *  @param env        The current environment.
5014          *  @param resultInfo    The expected result
5015          */
5016         Type checkId(JCTree tree,
5017                      Type site,
5018                      Symbol sym,
5019                      Env<AttrContext> env,
5020                      ResultInfo resultInfo) {
5021             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
5022                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
5023                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
5024         }
5025 
5026         Type checkMethodIdInternal(JCTree tree,
5027                      Type site,
5028                      Symbol sym,
5029                      Env<AttrContext> env,
5030                      ResultInfo resultInfo) {
5031             if (resultInfo.pkind.contains(KindSelector.POLY)) {
5032                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
5033             } else {
5034                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
5035             }
5036         }
5037 
5038         Type checkIdInternal(JCTree tree,
5039                      Type site,
5040                      Symbol sym,
5041                      Type pt,
5042                      Env<AttrContext> env,
5043                      ResultInfo resultInfo) {
5044             Type owntype; // The computed type of this identifier occurrence.
5045             switch (sym.kind) {
5046             case TYP:
5047                 // For types, the computed type equals the symbol's type,
5048                 // except for two situations:
5049                 owntype = sym.type;
5050                 if (owntype.hasTag(CLASS)) {
5051                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
5052                     Type ownOuter = owntype.getEnclosingType();
5053 
5054                     // (a) If the symbol's type is parameterized, erase it
5055                     // because no type parameters were given.
5056                     // We recover generic outer type later in visitTypeApply.
5057                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
5058                         owntype = types.erasure(owntype);
5059                     }
5060 
5061                     // (b) If the symbol's type is an inner class, then
5062                     // we have to interpret its outer type as a superclass
5063                     // of the site type. Example:
5064                     //
5065                     // class Tree<A> { class Visitor { ... } }
5066                     // class PointTree extends Tree<Point> { ... }
5067                     // ...PointTree.Visitor...
5068                     //
5069                     // Then the type of the last expression above is
5070                     // Tree<Point>.Visitor.
5071                     else if ((ownOuter.hasTag(CLASS) || ownOuter.hasTag(TYPEVAR)) && site != ownOuter) {
5072                         Type normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
5073                         if (normOuter == null) // perhaps from an import
5074                             normOuter = types.erasure(ownOuter);
5075                         if (normOuter != ownOuter)
5076                             owntype = new ClassType(
5077                                 normOuter, List.nil(), owntype.tsym,
5078                                 owntype.getMetadata());
5079                     }
5080                 }
5081                 break;
5082             case VAR:
5083                 VarSymbol v = (VarSymbol)sym;
5084 
5085                 if (env.info.enclVar != null
5086                         && v.type.hasTag(NONE)) {
5087                     //self reference to implicitly typed variable declaration
5088                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
5089                     return tree.type = v.type = types.createErrorType(v.type);
5090                 }
5091 
5092                 // Test (4): if symbol is an instance field of a raw type,
5093                 // which is being assigned to, issue an unchecked warning if
5094                 // its type changes under erasure.
5095                 if (KindSelector.ASG.subset(pkind()) &&
5096                     v.owner.kind == TYP &&
5097                     (v.flags() & STATIC) == 0 &&
5098                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
5099                     Type s = types.asOuterSuper(site, v.owner);
5100                     if (s != null &&
5101                         s.isRaw() &&
5102                         !types.isSameType(v.type, v.erasure(types))) {
5103                         chk.warnUnchecked(tree.pos(), LintWarnings.UncheckedAssignToVar(v, s));
5104                     }
5105                 }
5106                 // The computed type of a variable is the type of the
5107                 // variable symbol, taken as a member of the site type.
5108                 owntype = (sym.owner.kind == TYP &&
5109                            sym.name != names._this && sym.name != names._super)
5110                     ? types.memberType(site, sym)
5111                     : sym.type;
5112 
5113                 // If the variable is a constant, record constant value in
5114                 // computed type.
5115                 if (v.getConstValue() != null && isStaticReference(tree))
5116                     owntype = owntype.constType(v.getConstValue());
5117 
5118                 if (resultInfo.pkind == KindSelector.VAL) {
5119                     owntype = capture(owntype); // capture "names as expressions"
5120                 }
5121                 break;
5122             case MTH: {
5123                 owntype = checkMethod(site, sym,
5124                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
5125                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
5126                         resultInfo.pt.getTypeArguments());
5127                 chk.checkRestricted(tree.pos(), sym);
5128                 break;
5129             }
5130             case PCK: case ERR:
5131                 owntype = sym.type;
5132                 break;
5133             default:
5134                 throw new AssertionError("unexpected kind: " + sym.kind +
5135                                          " in tree " + tree);
5136             }
5137 
5138             // Emit a `deprecation' warning if symbol is deprecated.
5139             // (for constructors (but not for constructor references), the error
5140             // was given when the constructor was resolved)
5141 
5142             if (sym.name != names.init || tree.hasTag(REFERENCE)) {
5143                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
5144                 chk.checkSunAPI(tree.pos(), sym);
5145                 chk.checkProfile(tree.pos(), sym);
5146                 chk.checkPreview(tree.pos(), env.info.scope.owner, site, sym);
5147             }
5148 
5149             if (pt.isErroneous()) {
5150                 owntype = types.createErrorType(owntype);
5151             }
5152 
5153             // If symbol is a variable, check that its type and
5154             // kind are compatible with the prototype and protokind.
5155             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
5156         }
5157 
5158         /** Check that variable is initialized and evaluate the variable's
5159          *  initializer, if not yet done. Also check that variable is not
5160          *  referenced before it is defined.
5161          *  @param tree    The tree making up the variable reference.
5162          *  @param env     The current environment.
5163          *  @param v       The variable's symbol.
5164          */
5165         private void checkInit(JCTree tree,
5166                                Env<AttrContext> env,
5167                                VarSymbol v,
5168                                boolean onlyWarning) {
5169             // A forward reference is diagnosed if the declaration position
5170             // of the variable is greater than the current tree position
5171             // and the tree and variable definition occur in the same class
5172             // definition.  Note that writes don't count as references.
5173             // This check applies only to class and instance
5174             // variables.  Local variables follow different scope rules,
5175             // and are subject to definite assignment checking.
5176             Env<AttrContext> initEnv = enclosingInitEnv(env);
5177             if (initEnv != null &&
5178                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
5179                 v.owner.kind == TYP &&
5180                 v.owner == env.info.scope.owner.enclClass() &&
5181                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
5182                 (!env.tree.hasTag(ASSIGN) ||
5183                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
5184                 if (!onlyWarning || isStaticEnumField(v)) {
5185                     Error errkey = (initEnv.info.enclVar == v) ?
5186                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
5187                     log.error(tree.pos(), errkey);
5188                 } else if (useBeforeDeclarationWarning) {
5189                     Warning warnkey = (initEnv.info.enclVar == v) ?
5190                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
5191                     log.warning(tree.pos(), warnkey);
5192                 }
5193             }
5194 
5195             v.getConstValue(); // ensure initializer is evaluated
5196 
5197             checkEnumInitializer(tree, env, v);
5198         }
5199 
5200         /**
5201          * Returns the enclosing init environment associated with this env (if any). An init env
5202          * can be either a field declaration env or a static/instance initializer env.
5203          */
5204         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
5205             while (true) {
5206                 switch (env.tree.getTag()) {
5207                     case VARDEF:
5208                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
5209                         if (vdecl.sym.owner.kind == TYP) {
5210                             //field
5211                             return env;
5212                         }
5213                         break;
5214                     case BLOCK:
5215                         if (env.next.tree.hasTag(CLASSDEF)) {
5216                             //instance/static initializer
5217                             return env;
5218                         }
5219                         break;
5220                     case METHODDEF:
5221                     case CLASSDEF:
5222                     case TOPLEVEL:
5223                         return null;
5224                 }
5225                 Assert.checkNonNull(env.next);
5226                 env = env.next;
5227             }
5228         }
5229 
5230         /**
5231          * Check for illegal references to static members of enum.  In
5232          * an enum type, constructors and initializers may not
5233          * reference its static members unless they are constant.
5234          *
5235          * @param tree    The tree making up the variable reference.
5236          * @param env     The current environment.
5237          * @param v       The variable's symbol.
5238          * @jls 8.9 Enum Types
5239          */
5240         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
5241             // JLS:
5242             //
5243             // "It is a compile-time error to reference a static field
5244             // of an enum type that is not a compile-time constant
5245             // (15.28) from constructors, instance initializer blocks,
5246             // or instance variable initializer expressions of that
5247             // type. It is a compile-time error for the constructors,
5248             // instance initializer blocks, or instance variable
5249             // initializer expressions of an enum constant e to refer
5250             // to itself or to an enum constant of the same type that
5251             // is declared to the right of e."
5252             if (isStaticEnumField(v)) {
5253                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
5254 
5255                 if (enclClass == null || enclClass.owner == null)
5256                     return;
5257 
5258                 // See if the enclosing class is the enum (or a
5259                 // subclass thereof) declaring v.  If not, this
5260                 // reference is OK.
5261                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
5262                     return;
5263 
5264                 // If the reference isn't from an initializer, then
5265                 // the reference is OK.
5266                 if (!Resolve.isInitializer(env))
5267                     return;
5268 
5269                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
5270             }
5271         }
5272 
5273         /** Is the given symbol a static, non-constant field of an Enum?
5274          *  Note: enum literals should not be regarded as such
5275          */
5276         private boolean isStaticEnumField(VarSymbol v) {
5277             return Flags.isEnum(v.owner) &&
5278                    Flags.isStatic(v) &&
5279                    !Flags.isConstant(v) &&
5280                    v.name != names._class;
5281         }
5282 
5283     /**
5284      * Check that method arguments conform to its instantiation.
5285      **/
5286     public Type checkMethod(Type site,
5287                             final Symbol sym,
5288                             ResultInfo resultInfo,
5289                             Env<AttrContext> env,
5290                             final List<JCExpression> argtrees,
5291                             List<Type> argtypes,
5292                             List<Type> typeargtypes) {
5293         // Test (5): if symbol is an instance method of a raw type, issue
5294         // an unchecked warning if its argument types change under erasure.
5295         if ((sym.flags() & STATIC) == 0 &&
5296             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
5297             Type s = types.asOuterSuper(site, sym.owner);
5298             if (s != null && s.isRaw() &&
5299                 !types.isSameTypes(sym.type.getParameterTypes(),
5300                                    sym.erasure(types).getParameterTypes())) {
5301                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedCallMbrOfRawType(sym, s));
5302             }
5303         }
5304 
5305         if (env.info.defaultSuperCallSite != null) {
5306             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
5307                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
5308                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
5309                 List<MethodSymbol> icand_sup =
5310                         types.interfaceCandidates(sup, (MethodSymbol)sym);
5311                 if (icand_sup.nonEmpty() &&
5312                         icand_sup.head != sym &&
5313                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
5314                     log.error(env.tree.pos(),
5315                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
5316                     break;
5317                 }
5318             }
5319             env.info.defaultSuperCallSite = null;
5320         }
5321 
5322         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
5323             JCMethodInvocation app = (JCMethodInvocation)env.tree;
5324             if (app.meth.hasTag(SELECT) &&
5325                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
5326                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
5327             }
5328         }
5329 
5330         // Compute the identifier's instantiated type.
5331         // For methods, we need to compute the instance type by
5332         // Resolve.instantiate from the symbol's type as well as
5333         // any type arguments and value arguments.
5334         Warner noteWarner = new Warner();
5335         try {
5336             Type owntype = rs.checkMethod(
5337                     env,
5338                     site,
5339                     sym,
5340                     resultInfo,
5341                     argtypes,
5342                     typeargtypes,
5343                     noteWarner);
5344 
5345             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
5346                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
5347 
5348             argtypes = argtypes.map(checkDeferredMap);
5349 
5350             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
5351                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedMethInvocationApplied(kindName(sym),
5352                         sym.name,
5353                         rs.methodArguments(sym.type.getParameterTypes()),
5354                         rs.methodArguments(argtypes.map(checkDeferredMap)),
5355                         kindName(sym.location()),
5356                         sym.location()));
5357                 if (resultInfo.pt != Infer.anyPoly ||
5358                         !owntype.hasTag(METHOD) ||
5359                         !owntype.isPartial()) {
5360                     //if this is not a partially inferred method type, erase return type. Otherwise,
5361                     //erasure is carried out in PartiallyInferredMethodType.check().
5362                     owntype = new MethodType(owntype.getParameterTypes(),
5363                             types.erasure(owntype.getReturnType()),
5364                             types.erasure(owntype.getThrownTypes()),
5365                             syms.methodClass);
5366                 }
5367             }
5368 
5369             PolyKind pkind = (sym.type.hasTag(FORALL) &&
5370                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
5371                  PolyKind.POLY : PolyKind.STANDALONE;
5372             TreeInfo.setPolyKind(env.tree, pkind);
5373 
5374             return (resultInfo.pt == Infer.anyPoly) ?
5375                     owntype :
5376                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
5377                             resultInfo.checkContext.inferenceContext());
5378         } catch (Infer.InferenceException ex) {
5379             //invalid target type - propagate exception outwards or report error
5380             //depending on the current check context
5381             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
5382             return types.createErrorType(site);
5383         } catch (Resolve.InapplicableMethodException ex) {
5384             final JCDiagnostic diag = ex.getDiagnostic();
5385             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
5386                 @Override
5387                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
5388                     return new Pair<>(sym, diag);
5389                 }
5390             };
5391             List<Type> argtypes2 = argtypes.map(
5392                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
5393             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
5394                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
5395             log.report(errDiag);
5396             return types.createErrorType(site);
5397         }
5398     }
5399 
5400     public void visitLiteral(JCLiteral tree) {
5401         result = check(tree, litType(tree.typetag).constType(tree.value),
5402                 KindSelector.VAL, resultInfo);
5403     }
5404     //where
5405     /** Return the type of a literal with given type tag.
5406      */
5407     Type litType(TypeTag tag) {
5408         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
5409     }
5410 
5411     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5412         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5413     }
5414 
5415     public void visitTypeArray(JCArrayTypeTree tree) {
5416         Type etype = attribType(tree.elemtype, env);
5417         Type type = new ArrayType(etype, syms.arrayClass);
5418         result = check(tree, type, KindSelector.TYP, resultInfo);
5419     }
5420 
5421     /** Visitor method for parameterized types.
5422      *  Bound checking is left until later, since types are attributed
5423      *  before supertype structure is completely known
5424      */
5425     public void visitTypeApply(JCTypeApply tree) {
5426         Type owntype = types.createErrorType(tree.type);
5427 
5428         // Attribute functor part of application and make sure it's a class.
5429         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5430 
5431         // Attribute type parameters
5432         List<Type> actuals = attribTypes(tree.arguments, env);
5433 
5434         if (clazztype.hasTag(CLASS)) {
5435             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5436             if (actuals.isEmpty()) //diamond
5437                 actuals = formals;
5438 
5439             if (actuals.length() == formals.length()) {
5440                 List<Type> a = actuals;
5441                 List<Type> f = formals;
5442                 while (a.nonEmpty()) {
5443                     a.head = a.head.withTypeVar(f.head);
5444                     a = a.tail;
5445                     f = f.tail;
5446                 }
5447                 // Compute the proper generic outer
5448                 Type clazzOuter = clazztype.getEnclosingType();
5449                 if (clazzOuter.hasTag(CLASS)) {
5450                     Type site;
5451                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5452                     if (clazz.hasTag(IDENT)) {
5453                         site = env.enclClass.sym.type;
5454                     } else if (clazz.hasTag(SELECT)) {
5455                         site = ((JCFieldAccess) clazz).selected.type;
5456                     } else throw new AssertionError(""+tree);
5457                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5458                         if (site.hasTag(CLASS) || site.hasTag(TYPEVAR))
5459                             site = types.asEnclosingSuper(site, clazzOuter.tsym);
5460                         if (site == null)
5461                             site = types.erasure(clazzOuter);
5462                         clazzOuter = site;
5463                     }
5464                 }
5465                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5466                                         clazztype.getMetadata());
5467             } else {
5468                 if (formals.length() != 0) {
5469                     log.error(tree.pos(),
5470                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5471                 } else {
5472                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5473                 }
5474                 owntype = types.createErrorType(tree.type);
5475             }
5476         } else if (clazztype.hasTag(ERROR)) {
5477             ErrorType parameterizedErroneous =
5478                     new ErrorType(clazztype.getOriginalType(),
5479                                   clazztype.tsym,
5480                                   clazztype.getMetadata());
5481 
5482             parameterizedErroneous.typarams_field = actuals;
5483             owntype = parameterizedErroneous;
5484         }
5485         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5486     }
5487 
5488     public void visitTypeUnion(JCTypeUnion tree) {
5489         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5490         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5491         for (JCExpression typeTree : tree.alternatives) {
5492             Type ctype = attribType(typeTree, env);
5493             ctype = chk.checkType(typeTree.pos(),
5494                           chk.checkClassType(typeTree.pos(), ctype),
5495                           syms.throwableType);
5496             if (!ctype.isErroneous()) {
5497                 //check that alternatives of a union type are pairwise
5498                 //unrelated w.r.t. subtyping
5499                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5500                     for (Type t : multicatchTypes) {
5501                         boolean sub = types.isSubtype(ctype, t);
5502                         boolean sup = types.isSubtype(t, ctype);
5503                         if (sub || sup) {
5504                             //assume 'a' <: 'b'
5505                             Type a = sub ? ctype : t;
5506                             Type b = sub ? t : ctype;
5507                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5508                         }
5509                     }
5510                 }
5511                 multicatchTypes.append(ctype);
5512                 if (all_multicatchTypes != null)
5513                     all_multicatchTypes.append(ctype);
5514             } else {
5515                 if (all_multicatchTypes == null) {
5516                     all_multicatchTypes = new ListBuffer<>();
5517                     all_multicatchTypes.appendList(multicatchTypes);
5518                 }
5519                 all_multicatchTypes.append(ctype);
5520             }
5521         }
5522         Type t = check(tree, types.lub(multicatchTypes.toList()),
5523                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5524         if (t.hasTag(CLASS)) {
5525             List<Type> alternatives =
5526                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5527             t = new UnionClassType((ClassType) t, alternatives);
5528         }
5529         tree.type = result = t;
5530     }
5531 
5532     public void visitTypeIntersection(JCTypeIntersection tree) {
5533         attribTypes(tree.bounds, env);
5534         tree.type = result = checkIntersection(tree, tree.bounds);
5535     }
5536 
5537     public void visitTypeParameter(JCTypeParameter tree) {
5538         TypeVar typeVar = (TypeVar) tree.type;
5539 
5540         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5541             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5542         }
5543 
5544         if (!typeVar.getUpperBound().isErroneous()) {
5545             //fixup type-parameter bound computed in 'attribTypeVariables'
5546             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5547         }
5548     }
5549 
5550     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5551         Set<Symbol> boundSet = new HashSet<>();
5552         if (bounds.nonEmpty()) {
5553             // accept class or interface or typevar as first bound.
5554             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5555             boundSet.add(types.erasure(bounds.head.type).tsym);
5556             if (bounds.head.type.isErroneous()) {
5557                 return bounds.head.type;
5558             }
5559             else if (bounds.head.type.hasTag(TYPEVAR)) {
5560                 // if first bound was a typevar, do not accept further bounds.
5561                 if (bounds.tail.nonEmpty()) {
5562                     log.error(bounds.tail.head.pos(),
5563                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5564                     return bounds.head.type;
5565                 }
5566             } else {
5567                 // if first bound was a class or interface, accept only interfaces
5568                 // as further bounds.
5569                 for (JCExpression bound : bounds.tail) {
5570                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5571                     if (bound.type.isErroneous()) {
5572                         bounds = List.of(bound);
5573                     }
5574                     else if (bound.type.hasTag(CLASS)) {
5575                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5576                     }
5577                 }
5578             }
5579         }
5580 
5581         if (bounds.length() == 0) {
5582             return syms.objectType;
5583         } else if (bounds.length() == 1) {
5584             return bounds.head.type;
5585         } else {
5586             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5587             // ... the variable's bound is a class type flagged COMPOUND
5588             // (see comment for TypeVar.bound).
5589             // In this case, generate a class tree that represents the
5590             // bound class, ...
5591             JCExpression extending;
5592             List<JCExpression> implementing;
5593             if (!bounds.head.type.isInterface()) {
5594                 extending = bounds.head;
5595                 implementing = bounds.tail;
5596             } else {
5597                 extending = null;
5598                 implementing = bounds;
5599             }
5600             JCClassDecl cd = make.at(tree).ClassDef(
5601                 make.Modifiers(PUBLIC | ABSTRACT),
5602                 names.empty, List.nil(),
5603                 extending, implementing, List.nil());
5604 
5605             ClassSymbol c = (ClassSymbol)owntype.tsym;
5606             Assert.check((c.flags() & COMPOUND) != 0);
5607             cd.sym = c;
5608             c.sourcefile = env.toplevel.sourcefile;
5609 
5610             // ... and attribute the bound class
5611             c.flags_field |= UNATTRIBUTED;
5612             Env<AttrContext> cenv = enter.classEnv(cd, env);
5613             typeEnvs.put(c, cenv);
5614             attribClass(c);
5615             return owntype;
5616         }
5617     }
5618 
5619     public void visitWildcard(JCWildcard tree) {
5620         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5621         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5622             ? syms.objectType
5623             : attribType(tree.inner, env);
5624         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
5625                                               tree.kind.kind,
5626                                               syms.boundClass),
5627                 KindSelector.TYP, resultInfo);
5628     }
5629 
5630     public void visitAnnotation(JCAnnotation tree) {
5631         Assert.error("should be handled in annotate");
5632     }
5633 
5634     @Override
5635     public void visitModifiers(JCModifiers tree) {
5636         //error recovery only:
5637         Assert.check(resultInfo.pkind == KindSelector.ERR);
5638 
5639         attribAnnotationTypes(tree.annotations, env);
5640     }
5641 
5642     public void visitAnnotatedType(JCAnnotatedType tree) {
5643         attribAnnotationTypes(tree.annotations, env);
5644         Type underlyingType = attribType(tree.underlyingType, env);
5645         Type annotatedType = underlyingType.preannotatedType();
5646 
5647         annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5648         result = tree.type = annotatedType;
5649     }
5650 
5651     public void visitErroneous(JCErroneous tree) {
5652         if (tree.errs != null) {
5653             WriteableScope newScope = env.info.scope;
5654 
5655             if (env.tree instanceof JCClassDecl) {
5656                 Symbol fakeOwner =
5657                     new MethodSymbol(BLOCK, names.empty, null,
5658                         env.info.scope.owner);
5659                 newScope = newScope.dupUnshared(fakeOwner);
5660             }
5661 
5662             Env<AttrContext> errEnv =
5663                     env.dup(env.tree,
5664                             env.info.dup(newScope));
5665             errEnv.info.returnResult = unknownExprInfo;
5666             for (JCTree err : tree.errs)
5667                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5668         }
5669         result = tree.type = syms.errType;
5670     }
5671 
5672     /** Default visitor method for all other trees.
5673      */
5674     public void visitTree(JCTree tree) {
5675         throw new AssertionError();
5676     }
5677 
5678     /**
5679      * Attribute an env for either a top level tree or class or module declaration.
5680      */
5681     public void attrib(Env<AttrContext> env) {
5682         switch (env.tree.getTag()) {
5683             case MODULEDEF:
5684                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5685                 break;
5686             case PACKAGEDEF:
5687                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5688                 break;
5689             default:
5690                 attribClass(env.tree.pos(), env.enclClass.sym);
5691         }
5692 
5693         annotate.flush();
5694 
5695         // Now that this tree is attributed, we can calculate the Lint configuration everywhere within it
5696         lintMapper.calculateLints(env.toplevel.sourcefile, env.tree, env.toplevel.endPositions);
5697     }
5698 
5699     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5700         try {
5701             annotate.flush();
5702             attribPackage(p);
5703         } catch (CompletionFailure ex) {
5704             chk.completionError(pos, ex);
5705         }
5706     }
5707 
5708     void attribPackage(PackageSymbol p) {
5709         attribWithLint(p,
5710                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5711     }
5712 
5713     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5714         try {
5715             annotate.flush();
5716             attribModule(m);
5717         } catch (CompletionFailure ex) {
5718             chk.completionError(pos, ex);
5719         }
5720     }
5721 
5722     void attribModule(ModuleSymbol m) {
5723         attribWithLint(m, env -> attribStat(env.tree, env));
5724     }
5725 
5726     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5727         Env<AttrContext> env = typeEnvs.get(sym);
5728 
5729         Env<AttrContext> lintEnv = env;
5730         while (lintEnv.info.lint == null)
5731             lintEnv = lintEnv.next;
5732 
5733         Lint lint = lintEnv.info.lint.augment(sym);
5734 
5735         Lint prevLint = chk.setLint(lint);
5736         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5737 
5738         try {
5739             attrib.accept(env);
5740         } finally {
5741             log.useSource(prev);
5742             chk.setLint(prevLint);
5743         }
5744     }
5745 
5746     /** Main method: attribute class definition associated with given class symbol.
5747      *  reporting completion failures at the given position.
5748      *  @param pos The source position at which completion errors are to be
5749      *             reported.
5750      *  @param c   The class symbol whose definition will be attributed.
5751      */
5752     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5753         try {
5754             annotate.flush();
5755             attribClass(c);
5756         } catch (CompletionFailure ex) {
5757             chk.completionError(pos, ex);
5758         }
5759     }
5760 
5761     /** Attribute class definition associated with given class symbol.
5762      *  @param c   The class symbol whose definition will be attributed.
5763      */
5764     void attribClass(ClassSymbol c) throws CompletionFailure {
5765         if (c.type.hasTag(ERROR)) return;
5766 
5767         // Check for cycles in the inheritance graph, which can arise from
5768         // ill-formed class files.
5769         chk.checkNonCyclic(null, c.type);
5770 
5771         Type st = types.supertype(c.type);
5772         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5773             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0) {
5774             // First, attribute superclass.
5775             if (st.hasTag(CLASS))
5776                 attribClass((ClassSymbol)st.tsym);
5777 
5778             // Next attribute owner, if it is a class.
5779             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5780                 attribClass((ClassSymbol)c.owner);
5781 
5782             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5783         }
5784 
5785         // The previous operations might have attributed the current class
5786         // if there was a cycle. So we test first whether the class is still
5787         // UNATTRIBUTED.
5788         if ((c.flags_field & UNATTRIBUTED) != 0) {
5789             c.flags_field &= ~UNATTRIBUTED;
5790 
5791             // Get environment current at the point of class definition.
5792             Env<AttrContext> env = typeEnvs.get(c);
5793 
5794             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5795             // because the annotations were not available at the time the env was created. Therefore,
5796             // we look up the environment chain for the first enclosing environment for which the
5797             // lint value is set. Typically, this is the parent env, but might be further if there
5798             // are any envs created as a result of TypeParameter nodes.
5799             Env<AttrContext> lintEnv = env;
5800             while (lintEnv.info.lint == null)
5801                 lintEnv = lintEnv.next;
5802 
5803             // Having found the enclosing lint value, we can initialize the lint value for this class
5804             env.info.lint = lintEnv.info.lint.augment(c);
5805 
5806             Lint prevLint = chk.setLint(env.info.lint);
5807             JavaFileObject prev = log.useSource(c.sourcefile);
5808             ResultInfo prevReturnRes = env.info.returnResult;
5809 
5810             try {
5811                 if (c.isSealed() &&
5812                         !c.isEnum() &&
5813                         !c.isPermittedExplicit &&
5814                         c.getPermittedSubclasses().isEmpty()) {
5815                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5816                 }
5817 
5818                 if (c.isSealed()) {
5819                     Set<Symbol> permittedTypes = new HashSet<>();
5820                     boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5821                     for (Type subType : c.getPermittedSubclasses()) {
5822                         if (subType.isErroneous()) {
5823                             // the type already caused errors, don't produce more potentially misleading errors
5824                             continue;
5825                         }
5826                         boolean isTypeVar = false;
5827                         if (subType.getTag() == TYPEVAR) {
5828                             isTypeVar = true; //error recovery
5829                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5830                                     Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subType)));
5831                         }
5832                         if (subType.tsym.isAnonymous() && !c.isEnum()) {
5833                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5834                         }
5835                         if (permittedTypes.contains(subType.tsym)) {
5836                             DiagnosticPosition pos =
5837                                     env.enclClass.permitting.stream()
5838                                             .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subType.tsym, permittedExpr, true) != null)
5839                                             .limit(2).collect(List.collector()).get(1);
5840                             log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subType)));
5841                         } else {
5842                             permittedTypes.add(subType.tsym);
5843                         }
5844                         if (sealedInUnnamed) {
5845                             if (subType.tsym.packge() != c.packge()) {
5846                                 log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5847                                         Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5848                                 );
5849                             }
5850                         } else if (subType.tsym.packge().modle != c.packge().modle) {
5851                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5852                                     Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5853                             );
5854                         }
5855                         if (subType.tsym == c.type.tsym || types.isSuperType(subType, c.type)) {
5856                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, ((JCClassDecl)env.tree).permitting),
5857                                     Errors.InvalidPermitsClause(
5858                                             subType.tsym == c.type.tsym ?
5859                                                     Fragments.MustNotBeSameClass :
5860                                                     Fragments.MustNotBeSupertype(subType)
5861                                     )
5862                             );
5863                         } else if (!isTypeVar) {
5864                             boolean thisIsASuper = types.directSupertypes(subType)
5865                                                         .stream()
5866                                                         .anyMatch(d -> d.tsym == c);
5867                             if (!thisIsASuper) {
5868                                 if(c.isInterface()) {
5869                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5870                                             Errors.InvalidPermitsClause(Fragments.DoesntImplementSealed(kindName(subType.tsym), subType)));
5871                                 } else {
5872                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5873                                             Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subType)));
5874                                 }
5875                             }
5876                         }
5877                     }
5878                 }
5879 
5880                 List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5881                                                       .stream()
5882                                                       .filter(s -> s.tsym.isSealed())
5883                                                       .map(s -> (ClassSymbol) s.tsym)
5884                                                       .collect(List.collector());
5885 
5886                 if (sealedSupers.isEmpty()) {
5887                     if ((c.flags_field & Flags.NON_SEALED) != 0) {
5888                         boolean hasErrorSuper = false;
5889 
5890                         hasErrorSuper |= types.directSupertypes(c.type)
5891                                               .stream()
5892                                               .anyMatch(s -> s.tsym.kind == Kind.ERR);
5893 
5894                         ClassType ct = (ClassType) c.type;
5895 
5896                         hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5897 
5898                         if (!hasErrorSuper) {
5899                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5900                         }
5901                     }
5902                 } else if ((c.flags_field & Flags.COMPOUND) == 0) {
5903                     if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5904                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5905                     }
5906 
5907                     if (!c.type.isCompound()) {
5908                         for (ClassSymbol supertypeSym : sealedSupers) {
5909                             if (!supertypeSym.isPermittedSubclass(c.type.tsym)) {
5910                                 log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5911                             }
5912                         }
5913                         if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5914                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5915                                     c.isInterface() ?
5916                                             Errors.NonSealedOrSealedExpected :
5917                                             Errors.NonSealedSealedOrFinalExpected);
5918                         }
5919                     }
5920                 }
5921 
5922                 env.info.returnResult = null;
5923                 // java.lang.Enum may not be subclassed by a non-enum
5924                 if (st.tsym == syms.enumSym &&
5925                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5926                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5927 
5928                 // Enums may not be extended by source-level classes
5929                 if (st.tsym != null &&
5930                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5931                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5932                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5933                 }
5934 
5935                 if (rs.isSerializable(c.type)) {
5936                     env.info.isSerializable = true;
5937                 }
5938 
5939                 if (c.isValueClass()) {
5940                     Assert.check(env.tree.hasTag(CLASSDEF));
5941                     chk.checkConstraintsOfValueClass((JCClassDecl) env.tree, c);
5942                 }
5943 
5944                 attribClassBody(env, c);
5945 
5946                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5947                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5948                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5949                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5950 
5951                 if (c.isImplicit()) {
5952                     chk.checkHasMain(env.tree.pos(), c);
5953                 }
5954             } finally {
5955                 env.info.returnResult = prevReturnRes;
5956                 log.useSource(prev);
5957                 chk.setLint(prevLint);
5958             }
5959 
5960         }
5961     }
5962 
5963     public void visitImport(JCImport tree) {
5964         // nothing to do
5965     }
5966 
5967     public void visitModuleDef(JCModuleDecl tree) {
5968         tree.sym.completeUsesProvides();
5969         ModuleSymbol msym = tree.sym;
5970         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5971         Lint prevLint = chk.setLint(lint);
5972         try {
5973             chk.checkModuleName(tree);
5974             chk.checkDeprecatedAnnotation(tree, msym);
5975         } finally {
5976             chk.setLint(prevLint);
5977         }
5978     }
5979 
5980     /** Finish the attribution of a class. */
5981     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5982         JCClassDecl tree = (JCClassDecl)env.tree;
5983         Assert.check(c == tree.sym);
5984 
5985         // Validate type parameters, supertype and interfaces.
5986         attribStats(tree.typarams, env);
5987         if (!c.isAnonymous()) {
5988             //already checked if anonymous
5989             chk.validate(tree.typarams, env);
5990             chk.validate(tree.extending, env);
5991             chk.validate(tree.implementing, env);
5992         }
5993 
5994         chk.checkRequiresIdentity(tree, env.info.lint);
5995 
5996         c.markAbstractIfNeeded(types);
5997 
5998         // If this is a non-abstract class, check that it has no abstract
5999         // methods or unimplemented methods of an implemented interface.
6000         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
6001             chk.checkAllDefined(tree.pos(), c);
6002         }
6003 
6004         if ((c.flags() & ANNOTATION) != 0) {
6005             if (tree.implementing.nonEmpty())
6006                 log.error(tree.implementing.head.pos(),
6007                           Errors.CantExtendIntfAnnotation);
6008             if (tree.typarams.nonEmpty()) {
6009                 log.error(tree.typarams.head.pos(),
6010                           Errors.IntfAnnotationCantHaveTypeParams(c));
6011             }
6012 
6013             // If this annotation type has a @Repeatable, validate
6014             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
6015             // If this annotation type has a @Repeatable, validate
6016             if (repeatable != null) {
6017                 // get diagnostic position for error reporting
6018                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
6019                 Assert.checkNonNull(cbPos);
6020 
6021                 chk.validateRepeatable(c, repeatable, cbPos);
6022             }
6023         } else {
6024             // Check that all extended classes and interfaces
6025             // are compatible (i.e. no two define methods with same arguments
6026             // yet different return types).  (JLS 8.4.8.3)
6027             chk.checkCompatibleSupertypes(tree.pos(), c.type);
6028             chk.checkDefaultMethodClashes(tree.pos(), c.type);
6029             chk.checkPotentiallyAmbiguousOverloads(tree, c.type);
6030         }
6031 
6032         // Check that class does not import the same parameterized interface
6033         // with two different argument lists.
6034         chk.checkClassBounds(tree.pos(), c.type);
6035 
6036         tree.type = c.type;
6037 
6038         for (List<JCTypeParameter> l = tree.typarams;
6039              l.nonEmpty(); l = l.tail) {
6040              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
6041         }
6042 
6043         // Check that a generic class doesn't extend Throwable
6044         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
6045             log.error(tree.extending.pos(), Errors.GenericThrowable);
6046 
6047         // Check that all methods which implement some
6048         // method conform to the method they implement.
6049         chk.checkImplementations(tree);
6050 
6051         //check that a resource implementing AutoCloseable cannot throw InterruptedException
6052         checkAutoCloseable(env, tree, false);
6053 
6054         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
6055             // Attribute declaration
6056             attribStat(l.head, env);
6057             // Check that declarations in inner classes are not static (JLS 8.1.2)
6058             // Make an exception for static constants.
6059             if (!allowRecords &&
6060                     c.owner.kind != PCK &&
6061                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
6062                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
6063                 VarSymbol sym = null;
6064                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
6065                 if (sym == null ||
6066                         sym.kind != VAR ||
6067                         sym.getConstValue() == null)
6068                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
6069             }
6070         }
6071 
6072         // Check for proper placement of super()/this() calls.
6073         chk.checkSuperInitCalls(tree);
6074 
6075         // Check for cycles among non-initial constructors.
6076         chk.checkCyclicConstructors(tree);
6077 
6078         // Check for cycles among annotation elements.
6079         chk.checkNonCyclicElements(tree);
6080 
6081         // Check for proper use of serialVersionUID and other
6082         // serialization-related fields and methods
6083         if (env.info.lint.isEnabled(LintCategory.SERIAL)
6084                 && rs.isSerializable(c.type)
6085                 && !c.isAnonymous()) {
6086             chk.checkSerialStructure(env, tree, c);
6087         }
6088         // Correctly organize the positions of the type annotations
6089         typeAnnotations.organizeTypeAnnotationsBodies(tree);
6090 
6091         // Check type annotations applicability rules
6092         validateTypeAnnotations(tree, false);
6093     }
6094         // where
6095         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
6096         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
6097             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
6098                 if (types.isSameType(al.head.annotationType.type, t))
6099                     return al.head.pos();
6100             }
6101 
6102             return null;
6103         }
6104 
6105     private Type capture(Type type) {
6106         return types.capture(type);
6107     }
6108 
6109     private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
6110         if (type.isErroneous()) {
6111             tree.vartype = make.at(tree.pos()).Erroneous();
6112         } else if (tree.declaredUsingVar()) {
6113             Assert.check(tree.typePos != Position.NOPOS);
6114             tree.vartype = make.at(tree.typePos).Type(type);
6115         } else {
6116             tree.vartype = make.at(tree.pos()).Type(type);
6117         }
6118     }
6119 
6120     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
6121         tree.accept(new TypeAnnotationsValidator(sigOnly));
6122     }
6123     //where
6124     private final class TypeAnnotationsValidator extends TreeScanner {
6125 
6126         private final boolean sigOnly;
6127         public TypeAnnotationsValidator(boolean sigOnly) {
6128             this.sigOnly = sigOnly;
6129         }
6130 
6131         public void visitAnnotation(JCAnnotation tree) {
6132             chk.validateTypeAnnotation(tree, null, false);
6133             super.visitAnnotation(tree);
6134         }
6135         public void visitAnnotatedType(JCAnnotatedType tree) {
6136             if (!tree.underlyingType.type.isErroneous()) {
6137                 super.visitAnnotatedType(tree);
6138             }
6139         }
6140         public void visitTypeParameter(JCTypeParameter tree) {
6141             chk.validateTypeAnnotations(tree.annotations, tree.type.tsym, true);
6142             scan(tree.bounds);
6143             // Don't call super.
6144             // This is needed because above we call validateTypeAnnotation with
6145             // false, which would forbid annotations on type parameters.
6146             // super.visitTypeParameter(tree);
6147         }
6148         public void visitMethodDef(JCMethodDecl tree) {
6149             if (tree.recvparam != null &&
6150                     !tree.recvparam.vartype.type.isErroneous()) {
6151                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
6152             }
6153             if (tree.restype != null && tree.restype.type != null) {
6154                 validateAnnotatedType(tree.restype, tree.restype.type);
6155             }
6156             if (sigOnly) {
6157                 scan(tree.mods);
6158                 scan(tree.restype);
6159                 scan(tree.typarams);
6160                 scan(tree.recvparam);
6161                 scan(tree.params);
6162                 scan(tree.thrown);
6163             } else {
6164                 scan(tree.defaultValue);
6165                 scan(tree.body);
6166             }
6167         }
6168         public void visitVarDef(final JCVariableDecl tree) {
6169             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
6170             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
6171                 validateAnnotatedType(tree.vartype, tree.sym.type);
6172             scan(tree.mods);
6173             scan(tree.vartype);
6174             if (!sigOnly) {
6175                 scan(tree.init);
6176             }
6177         }
6178         public void visitTypeCast(JCTypeCast tree) {
6179             if (tree.clazz != null && tree.clazz.type != null)
6180                 validateAnnotatedType(tree.clazz, tree.clazz.type);
6181             super.visitTypeCast(tree);
6182         }
6183         public void visitTypeTest(JCInstanceOf tree) {
6184             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
6185                 validateAnnotatedType(tree.pattern, tree.pattern.type);
6186             super.visitTypeTest(tree);
6187         }
6188         public void visitNewClass(JCNewClass tree) {
6189             if (tree.clazz != null && tree.clazz.type != null) {
6190                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
6191                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
6192                             tree.clazz.type.tsym);
6193                 }
6194                 if (tree.def != null) {
6195                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
6196                 }
6197 
6198                 validateAnnotatedType(tree.clazz, tree.clazz.type);
6199             }
6200             super.visitNewClass(tree);
6201         }
6202         public void visitNewArray(JCNewArray tree) {
6203             if (tree.elemtype != null && tree.elemtype.type != null) {
6204                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
6205                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
6206                             tree.elemtype.type.tsym);
6207                 }
6208                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
6209             }
6210             super.visitNewArray(tree);
6211         }
6212         public void visitClassDef(JCClassDecl tree) {
6213             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
6214             if (sigOnly) {
6215                 scan(tree.mods);
6216                 scan(tree.typarams);
6217                 scan(tree.extending);
6218                 scan(tree.implementing);
6219             }
6220             for (JCTree member : tree.defs) {
6221                 if (member.hasTag(Tag.CLASSDEF)) {
6222                     continue;
6223                 }
6224                 scan(member);
6225             }
6226         }
6227         public void visitBlock(JCBlock tree) {
6228             if (!sigOnly) {
6229                 scan(tree.stats);
6230             }
6231         }
6232 
6233         /* I would want to model this after
6234          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
6235          * and override visitSelect and visitTypeApply.
6236          * However, we only set the annotated type in the top-level type
6237          * of the symbol.
6238          * Therefore, we need to override each individual location where a type
6239          * can occur.
6240          */
6241         private void validateAnnotatedType(final JCTree errtree, final Type type) {
6242             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
6243 
6244             if (type.isPrimitiveOrVoid()) {
6245                 return;
6246             }
6247 
6248             JCTree enclTr = errtree;
6249             Type enclTy = type;
6250 
6251             boolean repeat = true;
6252             while (repeat) {
6253                 if (enclTr.hasTag(TYPEAPPLY)) {
6254                     List<Type> tyargs = enclTy.getTypeArguments();
6255                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
6256                     if (trargs.length() > 0) {
6257                         // Nothing to do for diamonds
6258                         if (tyargs.length() == trargs.length()) {
6259                             for (int i = 0; i < tyargs.length(); ++i) {
6260                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
6261                             }
6262                         }
6263                         // If the lengths don't match, it's either a diamond
6264                         // or some nested type that redundantly provides
6265                         // type arguments in the tree.
6266                     }
6267 
6268                     // Look at the clazz part of a generic type
6269                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
6270                 }
6271 
6272                 if (enclTr.hasTag(SELECT)) {
6273                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
6274                     if (enclTy != null &&
6275                             !enclTy.hasTag(NONE)) {
6276                         enclTy = enclTy.getEnclosingType();
6277                     }
6278                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
6279                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
6280                     if (enclTy == null || enclTy.hasTag(NONE)) {
6281                         ListBuffer<Attribute.TypeCompound> onlyTypeAnnotationsBuf = new ListBuffer<>();
6282                         for (JCAnnotation an : at.getAnnotations()) {
6283                             if (chk.isTypeAnnotation(an, false)) {
6284                                 onlyTypeAnnotationsBuf.add((Attribute.TypeCompound) an.attribute);
6285                             }
6286                         }
6287                         List<Attribute.TypeCompound> onlyTypeAnnotations = onlyTypeAnnotationsBuf.toList();
6288                         if (!onlyTypeAnnotations.isEmpty()) {
6289                             Fragment annotationFragment = onlyTypeAnnotations.size() == 1 ?
6290                                     Fragments.TypeAnnotation1(onlyTypeAnnotations.head) :
6291                                     Fragments.TypeAnnotation(onlyTypeAnnotations);
6292                             JCDiagnostic.AnnotatedType annotatedType = new JCDiagnostic.AnnotatedType(
6293                                     type.stripMetadata().annotatedType(onlyTypeAnnotations));
6294                             log.error(at.underlyingType.pos(), Errors.TypeAnnotationInadmissible(annotationFragment,
6295                                     type.tsym.owner, annotatedType));
6296                         }
6297                         repeat = false;
6298                     }
6299                     enclTr = at.underlyingType;
6300                     // enclTy doesn't need to be changed
6301                 } else if (enclTr.hasTag(IDENT)) {
6302                     repeat = false;
6303                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
6304                     JCWildcard wc = (JCWildcard) enclTr;
6305                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
6306                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
6307                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
6308                     } else {
6309                         // Nothing to do for UNBOUND
6310                     }
6311                     repeat = false;
6312                 } else if (enclTr.hasTag(TYPEARRAY)) {
6313                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
6314                     validateAnnotatedType(art.getType(), art.elemtype.type);
6315                     repeat = false;
6316                 } else if (enclTr.hasTag(TYPEUNION)) {
6317                     JCTypeUnion ut = (JCTypeUnion) enclTr;
6318                     for (JCTree t : ut.getTypeAlternatives()) {
6319                         validateAnnotatedType(t, t.type);
6320                     }
6321                     repeat = false;
6322                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
6323                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
6324                     for (JCTree t : it.getBounds()) {
6325                         validateAnnotatedType(t, t.type);
6326                     }
6327                     repeat = false;
6328                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
6329                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
6330                     repeat = false;
6331                 } else {
6332                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
6333                             " within: "+ errtree + " with kind: " + errtree.getKind());
6334                 }
6335             }
6336         }
6337 
6338         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
6339                 Symbol sym) {
6340             // Ensure that no declaration annotations are present.
6341             // Note that a tree type might be an AnnotatedType with
6342             // empty annotations, if only declaration annotations were given.
6343             // This method will raise an error for such a type.
6344             for (JCAnnotation ai : annotations) {
6345                 if (!ai.type.isErroneous() &&
6346                         typeAnnotations.annotationTargetType(ai, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
6347                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
6348                 }
6349             }
6350         }
6351     }
6352 
6353     // <editor-fold desc="post-attribution visitor">
6354 
6355     /**
6356      * Handle missing types/symbols in an AST. This routine is useful when
6357      * the compiler has encountered some errors (which might have ended up
6358      * terminating attribution abruptly); if the compiler is used in fail-over
6359      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
6360      * prevents NPE to be propagated during subsequent compilation steps.
6361      */
6362     public void postAttr(JCTree tree) {
6363         new PostAttrAnalyzer().scan(tree);
6364     }
6365 
6366     class PostAttrAnalyzer extends TreeScanner {
6367 
6368         private void initTypeIfNeeded(JCTree that) {
6369             if (that.type == null) {
6370                 if (that.hasTag(METHODDEF)) {
6371                     that.type = dummyMethodType((JCMethodDecl)that);
6372                 } else {
6373                     that.type = syms.unknownType;
6374                 }
6375             }
6376         }
6377 
6378         /* Construct a dummy method type. If we have a method declaration,
6379          * and the declared return type is void, then use that return type
6380          * instead of UNKNOWN to avoid spurious error messages in lambda
6381          * bodies (see:JDK-8041704).
6382          */
6383         private Type dummyMethodType(JCMethodDecl md) {
6384             Type restype = syms.unknownType;
6385             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
6386                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
6387                 if (prim.typetag == VOID)
6388                     restype = syms.voidType;
6389             }
6390             return new MethodType(List.nil(), restype,
6391                                   List.nil(), syms.methodClass);
6392         }
6393         private Type dummyMethodType() {
6394             return dummyMethodType(null);
6395         }
6396 
6397         @Override
6398         public void scan(JCTree tree) {
6399             if (tree == null) return;
6400             if (tree instanceof JCExpression) {
6401                 initTypeIfNeeded(tree);
6402             }
6403             super.scan(tree);
6404         }
6405 
6406         @Override
6407         public void visitIdent(JCIdent that) {
6408             if (that.sym == null) {
6409                 that.sym = syms.unknownSymbol;
6410             }
6411         }
6412 
6413         @Override
6414         public void visitSelect(JCFieldAccess that) {
6415             if (that.sym == null) {
6416                 that.sym = syms.unknownSymbol;
6417             }
6418             super.visitSelect(that);
6419         }
6420 
6421         @Override
6422         public void visitClassDef(JCClassDecl that) {
6423             initTypeIfNeeded(that);
6424             if (that.sym == null) {
6425                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
6426             }
6427             super.visitClassDef(that);
6428         }
6429 
6430         @Override
6431         public void visitMethodDef(JCMethodDecl that) {
6432             initTypeIfNeeded(that);
6433             if (that.sym == null) {
6434                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
6435             }
6436             super.visitMethodDef(that);
6437         }
6438 
6439         @Override
6440         public void visitVarDef(JCVariableDecl that) {
6441             initTypeIfNeeded(that);
6442             if (that.sym == null) {
6443                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
6444                 that.sym.adr = 0;
6445             }
6446             if (that.vartype == null) {
6447                 that.vartype = make.at(Position.NOPOS).Erroneous();
6448             }
6449             super.visitVarDef(that);
6450         }
6451 
6452         @Override
6453         public void visitBindingPattern(JCBindingPattern that) {
6454             initTypeIfNeeded(that);
6455             initTypeIfNeeded(that.var);
6456             if (that.var.sym == null) {
6457                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6458                 that.var.sym.adr = 0;
6459             }
6460             super.visitBindingPattern(that);
6461         }
6462 
6463         @Override
6464         public void visitRecordPattern(JCRecordPattern that) {
6465             initTypeIfNeeded(that);
6466             if (that.record == null) {
6467                 that.record = new ClassSymbol(0, TreeInfo.name(that.deconstructor),
6468                                               that.type, syms.noSymbol);
6469             }
6470             if (that.fullComponentTypes == null) {
6471                 that.fullComponentTypes = List.nil();
6472             }
6473             super.visitRecordPattern(that);
6474         }
6475 
6476         @Override
6477         public void visitNewClass(JCNewClass that) {
6478             if (that.constructor == null) {
6479                 that.constructor = new MethodSymbol(0, names.init,
6480                         dummyMethodType(), syms.noSymbol);
6481             }
6482             if (that.constructorType == null) {
6483                 that.constructorType = syms.unknownType;
6484             }
6485             super.visitNewClass(that);
6486         }
6487 
6488         @Override
6489         public void visitAssignop(JCAssignOp that) {
6490             if (that.operator == null) {
6491                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6492                         -1, syms.noSymbol);
6493             }
6494             super.visitAssignop(that);
6495         }
6496 
6497         @Override
6498         public void visitBinary(JCBinary that) {
6499             if (that.operator == null) {
6500                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6501                         -1, syms.noSymbol);
6502             }
6503             super.visitBinary(that);
6504         }
6505 
6506         @Override
6507         public void visitUnary(JCUnary that) {
6508             if (that.operator == null) {
6509                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6510                         -1, syms.noSymbol);
6511             }
6512             super.visitUnary(that);
6513         }
6514 
6515         @Override
6516         public void visitReference(JCMemberReference that) {
6517             super.visitReference(that);
6518             if (that.sym == null) {
6519                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6520                         syms.noSymbol);
6521             }
6522         }
6523     }
6524     // </editor-fold>
6525 
6526     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6527         new TreeScanner() {
6528             Symbol packge = pkg;
6529             @Override
6530             public void visitIdent(JCIdent that) {
6531                 that.sym = packge;
6532             }
6533 
6534             @Override
6535             public void visitSelect(JCFieldAccess that) {
6536                 that.sym = packge;
6537                 packge = packge.owner;
6538                 super.visitSelect(that);
6539             }
6540         }.scan(pid);
6541     }
6542 
6543 }
--- EOF ---