1 /*
   2  * Copyright (c) 1999, 2023, 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.Scope.WriteableScope;
  45 import com.sun.tools.javac.code.Source.Feature;
  46 import com.sun.tools.javac.code.Symbol.*;
  47 import com.sun.tools.javac.code.Type.*;
  48 import com.sun.tools.javac.code.Types.FunctionDescriptorLookupError;
  49 import com.sun.tools.javac.comp.ArgumentAttr.LocalCacheContext;
  50 import com.sun.tools.javac.comp.Check.CheckContext;
  51 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
  52 import com.sun.tools.javac.comp.MatchBindingsComputer.MatchBindings;
  53 import com.sun.tools.javac.jvm.*;
  54 
  55 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
  56 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
  57 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
  58 
  59 import com.sun.tools.javac.resources.CompilerProperties.Errors;
  60 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  61 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
  62 import com.sun.tools.javac.tree.*;
  63 import com.sun.tools.javac.tree.JCTree.*;
  64 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
  65 import com.sun.tools.javac.util.*;
  66 import com.sun.tools.javac.util.DefinedBy.Api;
  67 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  68 import com.sun.tools.javac.util.JCDiagnostic.Error;
  69 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
  70 import com.sun.tools.javac.util.JCDiagnostic.Warning;
  71 import com.sun.tools.javac.util.List;
  72 
  73 import static com.sun.tools.javac.code.Flags.*;
  74 import static com.sun.tools.javac.code.Flags.ANNOTATION;
  75 import static com.sun.tools.javac.code.Flags.BLOCK;
  76 import static com.sun.tools.javac.code.Kinds.*;
  77 import static com.sun.tools.javac.code.Kinds.Kind.*;
  78 import static com.sun.tools.javac.code.TypeTag.*;
  79 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
  80 import static com.sun.tools.javac.tree.JCTree.Tag.*;
  81 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
  82 
  83 /** This is the main context-dependent analysis phase in GJC. It
  84  *  encompasses name resolution, type checking and constant folding as
  85  *  subtasks. Some subtasks involve auxiliary classes.
  86  *  @see Check
  87  *  @see Resolve
  88  *  @see ConstFold
  89  *  @see Infer
  90  *
  91  *  <p><b>This is NOT part of any supported API.
  92  *  If you write code that depends on this, you do so at your own risk.
  93  *  This code and its internal interfaces are subject to change or
  94  *  deletion without notice.</b>
  95  */
  96 public class Attr extends JCTree.Visitor {
  97     protected static final Context.Key<Attr> attrKey = new Context.Key<>();
  98 
  99     final Names names;
 100     final Log log;
 101     final Symtab syms;
 102     final Resolve rs;
 103     final Operators operators;
 104     final Infer infer;
 105     final Analyzer analyzer;
 106     final DeferredAttr deferredAttr;
 107     final Check chk;
 108     final Flow flow;
 109     final MemberEnter memberEnter;
 110     final TypeEnter typeEnter;
 111     final TreeMaker make;
 112     final ConstFold cfolder;
 113     final Enter enter;
 114     final Target target;
 115     final Types types;
 116     final Preview preview;
 117     final JCDiagnostic.Factory diags;
 118     final TypeAnnotations typeAnnotations;
 119     final DeferredLintHandler deferredLintHandler;
 120     final TypeEnvs typeEnvs;
 121     final Dependencies dependencies;
 122     final Annotate annotate;
 123     final ArgumentAttr argumentAttr;
 124     final MatchBindingsComputer matchBindingsComputer;
 125     final AttrRecover attrRecover;
 126 
 127     public static Attr instance(Context context) {
 128         Attr instance = context.get(attrKey);
 129         if (instance == null)
 130             instance = new Attr(context);
 131         return instance;
 132     }
 133 
 134     @SuppressWarnings("this-escape")
 135     protected Attr(Context context) {
 136         context.put(attrKey, this);
 137 
 138         names = Names.instance(context);
 139         log = Log.instance(context);
 140         syms = Symtab.instance(context);
 141         rs = Resolve.instance(context);
 142         operators = Operators.instance(context);
 143         chk = Check.instance(context);
 144         flow = Flow.instance(context);
 145         memberEnter = MemberEnter.instance(context);
 146         typeEnter = TypeEnter.instance(context);
 147         make = TreeMaker.instance(context);
 148         enter = Enter.instance(context);
 149         infer = Infer.instance(context);
 150         analyzer = Analyzer.instance(context);
 151         deferredAttr = DeferredAttr.instance(context);
 152         cfolder = ConstFold.instance(context);
 153         target = Target.instance(context);
 154         types = Types.instance(context);
 155         preview = Preview.instance(context);
 156         diags = JCDiagnostic.Factory.instance(context);
 157         annotate = Annotate.instance(context);
 158         typeAnnotations = TypeAnnotations.instance(context);
 159         deferredLintHandler = DeferredLintHandler.instance(context);
 160         typeEnvs = TypeEnvs.instance(context);
 161         dependencies = Dependencies.instance(context);
 162         argumentAttr = ArgumentAttr.instance(context);
 163         matchBindingsComputer = MatchBindingsComputer.instance(context);
 164         attrRecover = AttrRecover.instance(context);
 165 
 166         Options options = Options.instance(context);
 167 
 168         Source source = Source.instance(context);
 169         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 170         allowRecords = Feature.RECORDS.allowedInSource(source);
 171         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 172                              Feature.PATTERN_SWITCH.allowedInSource(source);
 173         allowUnconditionalPatternsInstanceOf =
 174                              Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 175         sourceName = source.name;
 176         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 177 
 178         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 179         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 180         unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
 181         methodAttrInfo = new MethodAttrInfo();
 182         unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
 183         unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
 184         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
 185     }
 186 
 187     /** Switch: reifiable types in instanceof enabled?
 188      */
 189     boolean allowReifiableTypesInInstanceof;
 190 
 191     /** Are records allowed
 192      */
 193     private final boolean allowRecords;
 194 
 195     /** Are patterns in switch allowed
 196      */
 197     private final boolean allowPatternSwitch;
 198 
 199     /** Are unconditional patterns in instanceof allowed
 200      */
 201     private final boolean allowUnconditionalPatternsInstanceOf;
 202 
 203     /**
 204      * Switch: warn about use of variable before declaration?
 205      * RFE: 6425594
 206      */
 207     boolean useBeforeDeclarationWarning;
 208 
 209     /**
 210      * Switch: name of source level; used for error reporting.
 211      */
 212     String sourceName;
 213 
 214     /** Check kind and type of given tree against protokind and prototype.
 215      *  If check succeeds, store type in tree and return it.
 216      *  If check fails, store errType in tree and return it.
 217      *  No checks are performed if the prototype is a method type.
 218      *  It is not necessary in this case since we know that kind and type
 219      *  are correct.
 220      *
 221      *  @param tree     The tree whose kind and type is checked
 222      *  @param found    The computed type of the tree
 223      *  @param ownkind  The computed kind of the tree
 224      *  @param resultInfo  The expected result of the tree
 225      */
 226     Type check(final JCTree tree,
 227                final Type found,
 228                final KindSelector ownkind,
 229                final ResultInfo resultInfo) {
 230         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 231         Type owntype;
 232         boolean shouldCheck = !found.hasTag(ERROR) &&
 233                 !resultInfo.pt.hasTag(METHOD) &&
 234                 !resultInfo.pt.hasTag(FORALL);
 235         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 236             log.error(tree.pos(),
 237                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 238                                             ownkind.kindNames()));
 239             owntype = types.createErrorType(found);
 240         } else if (inferenceContext.free(found)) {
 241             //delay the check if there are inference variables in the found type
 242             //this means we are dealing with a partially inferred poly expression
 243             owntype = shouldCheck ? resultInfo.pt : found;
 244             if (resultInfo.checkMode.installPostInferenceHook()) {
 245                 inferenceContext.addFreeTypeListener(List.of(found),
 246                         instantiatedContext -> {
 247                             ResultInfo pendingResult =
 248                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 249                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 250                         });
 251             }
 252         } else {
 253             owntype = shouldCheck ?
 254             resultInfo.check(tree, found) :
 255             found;
 256         }
 257         if (resultInfo.checkMode.updateTreeType()) {
 258             tree.type = owntype;
 259         }
 260         return owntype;
 261     }
 262 
 263     /** Is given blank final variable assignable, i.e. in a scope where it
 264      *  may be assigned to even though it is final?
 265      *  @param v      The blank final variable.
 266      *  @param env    The current environment.
 267      */
 268     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 269         Symbol owner = env.info.scope.owner;
 270            // owner refers to the innermost variable, method or
 271            // initializer block declaration at this point.
 272         boolean isAssignable =
 273             v.owner == owner
 274             ||
 275             ((owner.name == names.init ||    // i.e. we are in a constructor
 276               owner.kind == VAR ||           // i.e. we are in a variable initializer
 277               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 278              &&
 279              v.owner == owner.owner
 280              &&
 281              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 282         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 283         return isAssignable & !insideCompactConstructor;
 284     }
 285 
 286     /** Check that variable can be assigned to.
 287      *  @param pos    The current source code position.
 288      *  @param v      The assigned variable
 289      *  @param base   If the variable is referred to in a Select, the part
 290      *                to the left of the `.', null otherwise.
 291      *  @param env    The current environment.
 292      */
 293     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 294         if (v.name == names._this) {
 295             log.error(pos, Errors.CantAssignValToThis);
 296         } else if ((v.flags() & FINAL) != 0 &&
 297             ((v.flags() & HASINIT) != 0
 298              ||
 299              !((base == null ||
 300                TreeInfo.isThisQualifier(base)) &&
 301                isAssignableAsBlankFinal(v, env)))) {
 302             if (v.isResourceVariable()) { //TWR resource
 303                 log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
 304             } else {
 305                 log.error(pos, Errors.CantAssignValToVar(Flags.toSource(v.flags() & (STATIC | FINAL)), v));
 306             }
 307         }











 308     }
 309 
 310     /** Does tree represent a static reference to an identifier?
 311      *  It is assumed that tree is either a SELECT or an IDENT.
 312      *  We have to weed out selects from non-type names here.
 313      *  @param tree    The candidate tree.
 314      */
 315     boolean isStaticReference(JCTree tree) {
 316         if (tree.hasTag(SELECT)) {
 317             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 318             if (lsym == null || lsym.kind != TYP) {
 319                 return false;
 320             }
 321         }
 322         return true;
 323     }
 324 
 325     /** Is this symbol a type?
 326      */
 327     static boolean isType(Symbol sym) {
 328         return sym != null && sym.kind == TYP;
 329     }
 330 
 331     /** The current `this' symbol.
 332      *  @param env    The current environment.
 333      */
 334     Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
 335         return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
 336     }
 337 
 338     /** Attribute a parsed identifier.
 339      * @param tree Parsed identifier name
 340      * @param topLevel The toplevel to use
 341      */
 342     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 343         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 344         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 345                                            syms.errSymbol.name,
 346                                            null, null, null, null);
 347         localEnv.enclClass.sym = syms.errSymbol;
 348         return attribIdent(tree, localEnv);
 349     }
 350 
 351     /** Attribute a parsed identifier.
 352      * @param tree Parsed identifier name
 353      * @param env The env to use
 354      */
 355     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 356         return tree.accept(identAttributer, env);
 357     }
 358     // where
 359         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 360         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 361             @Override @DefinedBy(Api.COMPILER_TREE)
 362             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 363                 Symbol site = visit(node.getExpression(), env);
 364                 if (site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 365                     return site;
 366                 Name name = (Name)node.getIdentifier();
 367                 if (site.kind == PCK) {
 368                     env.toplevel.packge = (PackageSymbol)site;
 369                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 370                             KindSelector.TYP_PCK);
 371                 } else {
 372                     env.enclClass.sym = (ClassSymbol)site;
 373                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 374                 }
 375             }
 376 
 377             @Override @DefinedBy(Api.COMPILER_TREE)
 378             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 379                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 380             }
 381         }
 382 
 383     public Type coerce(Type etype, Type ttype) {
 384         return cfolder.coerce(etype, ttype);
 385     }
 386 
 387     public Type attribType(JCTree node, TypeSymbol sym) {
 388         Env<AttrContext> env = typeEnvs.get(sym);
 389         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 390         return attribTree(node, localEnv, unknownTypeInfo);
 391     }
 392 
 393     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 394         // Attribute qualifying package or class.
 395         JCFieldAccess s = tree.qualid;
 396         return attribTree(s.selected, env,
 397                           new ResultInfo(tree.staticImport ?
 398                                          KindSelector.TYP : KindSelector.TYP_PCK,
 399                        Type.noType));
 400     }
 401 
 402     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 403         return attribToTree(expr, env, tree, unknownExprInfo);
 404     }
 405 
 406     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 407         return attribToTree(stmt, env, tree, statInfo);
 408     }
 409 
 410     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 411         breakTree = tree;
 412         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 413         try {
 414             deferredAttr.attribSpeculative(root, env, resultInfo,
 415                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 416                     argumentAttr.withLocalCacheContext());
 417             attrRecover.doRecovery();
 418         } catch (BreakAttr b) {
 419             return b.env;
 420         } catch (AssertionError ae) {
 421             if (ae.getCause() instanceof BreakAttr breakAttr) {
 422                 return breakAttr.env;
 423             } else {
 424                 throw ae;
 425             }
 426         } finally {
 427             breakTree = null;
 428             log.useSource(prev);
 429         }
 430         return env;
 431     }
 432 
 433     private JCTree breakTree = null;
 434 
 435     private static class BreakAttr extends RuntimeException {
 436         static final long serialVersionUID = -6924771130405446405L;
 437         private transient Env<AttrContext> env;
 438         private BreakAttr(Env<AttrContext> env) {
 439             this.env = env;
 440         }
 441     }
 442 
 443     /**
 444      * Mode controlling behavior of Attr.Check
 445      */
 446     enum CheckMode {
 447 
 448         NORMAL,
 449 
 450         /**
 451          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 452          * that the captured var cache in {@code InferenceContext} will be used in read-only
 453          * mode when performing inference checks.
 454          */
 455         NO_TREE_UPDATE {
 456             @Override
 457             public boolean updateTreeType() {
 458                 return false;
 459             }
 460         },
 461         /**
 462          * Mode signalling that caller will manage free types in tree decorations.
 463          */
 464         NO_INFERENCE_HOOK {
 465             @Override
 466             public boolean installPostInferenceHook() {
 467                 return false;
 468             }
 469         };
 470 
 471         public boolean updateTreeType() {
 472             return true;
 473         }
 474         public boolean installPostInferenceHook() {
 475             return true;
 476         }
 477     }
 478 
 479 
 480     class ResultInfo {
 481         final KindSelector pkind;
 482         final Type pt;
 483         final CheckContext checkContext;
 484         final CheckMode checkMode;
 485 
 486         ResultInfo(KindSelector pkind, Type pt) {
 487             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 488         }
 489 
 490         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 491             this(pkind, pt, chk.basicHandler, checkMode);
 492         }
 493 
 494         protected ResultInfo(KindSelector pkind,
 495                              Type pt, CheckContext checkContext) {
 496             this(pkind, pt, checkContext, CheckMode.NORMAL);
 497         }
 498 
 499         protected ResultInfo(KindSelector pkind,
 500                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 501             this.pkind = pkind;
 502             this.pt = pt;
 503             this.checkContext = checkContext;
 504             this.checkMode = checkMode;
 505         }
 506 
 507         /**
 508          * Should {@link Attr#attribTree} use the {@code ArgumentAttr} visitor instead of this one?
 509          * @param tree The tree to be type-checked.
 510          * @return true if {@code ArgumentAttr} should be used.
 511          */
 512         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 513 
 514         protected Type check(final DiagnosticPosition pos, final Type found) {
 515             return chk.checkType(pos, found, pt, checkContext);
 516         }
 517 
 518         protected ResultInfo dup(Type newPt) {
 519             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 520         }
 521 
 522         protected ResultInfo dup(CheckContext newContext) {
 523             return new ResultInfo(pkind, pt, newContext, checkMode);
 524         }
 525 
 526         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 527             return new ResultInfo(pkind, newPt, newContext, checkMode);
 528         }
 529 
 530         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 531             return new ResultInfo(pkind, newPt, newContext, newMode);
 532         }
 533 
 534         protected ResultInfo dup(CheckMode newMode) {
 535             return new ResultInfo(pkind, pt, checkContext, newMode);
 536         }
 537 
 538         @Override
 539         public String toString() {
 540             if (pt != null) {
 541                 return pt.toString();
 542             } else {
 543                 return "";
 544             }
 545         }
 546     }
 547 
 548     class MethodAttrInfo extends ResultInfo {
 549         public MethodAttrInfo() {
 550             this(chk.basicHandler);
 551         }
 552 
 553         public MethodAttrInfo(CheckContext checkContext) {
 554             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 555         }
 556 
 557         @Override
 558         protected boolean needsArgumentAttr(JCTree tree) {
 559             return true;
 560         }
 561 
 562         protected ResultInfo dup(Type newPt) {
 563             throw new IllegalStateException();
 564         }
 565 
 566         protected ResultInfo dup(CheckContext newContext) {
 567             return new MethodAttrInfo(newContext);
 568         }
 569 
 570         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 571             throw new IllegalStateException();
 572         }
 573 
 574         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 575             throw new IllegalStateException();
 576         }
 577 
 578         protected ResultInfo dup(CheckMode newMode) {
 579             throw new IllegalStateException();
 580         }
 581     }
 582 
 583     class RecoveryInfo extends ResultInfo {
 584 
 585         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 586             this(deferredAttrContext, Type.recoveryType);
 587         }
 588 
 589         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 590             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 591                 @Override
 592                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 593                     return deferredAttrContext;
 594                 }
 595                 @Override
 596                 public boolean compatible(Type found, Type req, Warner warn) {
 597                     return true;
 598                 }
 599                 @Override
 600                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 601                     boolean needsReport = pt == Type.recoveryType ||
 602                             (details.getDiagnosticPosition() != null &&
 603                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 604                     if (needsReport) {
 605                         chk.basicHandler.report(pos, details);
 606                     }
 607                 }
 608             });
 609         }
 610     }
 611 
 612     final ResultInfo statInfo;
 613     final ResultInfo varAssignmentInfo;
 614     final ResultInfo methodAttrInfo;
 615     final ResultInfo unknownExprInfo;
 616     final ResultInfo unknownTypeInfo;
 617     final ResultInfo unknownTypeExprInfo;
 618     final ResultInfo recoveryInfo;
 619 
 620     Type pt() {
 621         return resultInfo.pt;
 622     }
 623 
 624     KindSelector pkind() {
 625         return resultInfo.pkind;
 626     }
 627 
 628 /* ************************************************************************
 629  * Visitor methods
 630  *************************************************************************/
 631 
 632     /** Visitor argument: the current environment.
 633      */
 634     Env<AttrContext> env;
 635 
 636     /** Visitor argument: the currently expected attribution result.
 637      */
 638     ResultInfo resultInfo;
 639 
 640     /** Visitor result: the computed type.
 641      */
 642     Type result;
 643 
 644     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 645 
 646     /** Visitor method: attribute a tree, catching any completion failure
 647      *  exceptions. Return the tree's type.
 648      *
 649      *  @param tree    The tree to be visited.
 650      *  @param env     The environment visitor argument.
 651      *  @param resultInfo   The result info visitor argument.
 652      */
 653     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 654         Env<AttrContext> prevEnv = this.env;
 655         ResultInfo prevResult = this.resultInfo;
 656         try {
 657             this.env = env;
 658             this.resultInfo = resultInfo;
 659             if (resultInfo.needsArgumentAttr(tree)) {
 660                 result = argumentAttr.attribArg(tree, env);
 661             } else {
 662                 tree.accept(this);
 663             }
 664             matchBindings = matchBindingsComputer.finishBindings(tree,
 665                                                                  matchBindings);
 666             if (tree == breakTree &&
 667                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 668                 breakTreeFound(copyEnv(env));
 669             }
 670             return result;
 671         } catch (CompletionFailure ex) {
 672             tree.type = syms.errType;
 673             return chk.completionError(tree.pos(), ex);
 674         } finally {
 675             this.env = prevEnv;
 676             this.resultInfo = prevResult;
 677         }
 678     }
 679 
 680     protected void breakTreeFound(Env<AttrContext> env) {
 681         throw new BreakAttr(env);
 682     }
 683 
 684     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 685         Env<AttrContext> newEnv =
 686                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 687         if (newEnv.outer != null) {
 688             newEnv.outer = copyEnv(newEnv.outer);
 689         }
 690         return newEnv;
 691     }
 692 
 693     WriteableScope copyScope(WriteableScope sc) {
 694         WriteableScope newScope = WriteableScope.create(sc.owner);
 695         List<Symbol> elemsList = List.nil();
 696         for (Symbol sym : sc.getSymbols()) {
 697             elemsList = elemsList.prepend(sym);
 698         }
 699         for (Symbol s : elemsList) {
 700             newScope.enter(s);
 701         }
 702         return newScope;
 703     }
 704 
 705     /** Derived visitor method: attribute an expression tree.
 706      */
 707     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 708         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 709     }
 710 
 711     /** Derived visitor method: attribute an expression tree with
 712      *  no constraints on the computed type.
 713      */
 714     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 715         return attribTree(tree, env, unknownExprInfo);
 716     }
 717 
 718     /** Derived visitor method: attribute a type tree.
 719      */
 720     public Type attribType(JCTree tree, Env<AttrContext> env) {
 721         Type result = attribType(tree, env, Type.noType);
 722         return result;
 723     }
 724 
 725     /** Derived visitor method: attribute a type tree.
 726      */
 727     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 728         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 729         return result;
 730     }
 731 
 732     /** Derived visitor method: attribute a statement or definition tree.
 733      */
 734     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 735         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 736         Type result = attribTree(tree, env, statInfo);
 737         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 738         attrRecover.doRecovery();
 739         return result;
 740     }
 741 
 742     /** Attribute a list of expressions, returning a list of types.
 743      */
 744     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 745         ListBuffer<Type> ts = new ListBuffer<>();
 746         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 747             ts.append(attribExpr(l.head, env, pt));
 748         return ts.toList();
 749     }
 750 
 751     /** Attribute a list of statements, returning nothing.
 752      */
 753     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 754         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 755             attribStat(l.head, env);
 756     }
 757 
 758     /** Attribute the arguments in a method call, returning the method kind.
 759      */
 760     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 761         KindSelector kind = initialKind;
 762         for (JCExpression arg : trees) {
 763             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 764             if (argtype.hasTag(DEFERRED)) {
 765                 kind = KindSelector.of(KindSelector.POLY, kind);
 766             }
 767             argtypes.append(argtype);
 768         }
 769         return kind;
 770     }
 771 
 772     /** Attribute a type argument list, returning a list of types.
 773      *  Caller is responsible for calling checkRefTypes.
 774      */
 775     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 776         ListBuffer<Type> argtypes = new ListBuffer<>();
 777         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 778             argtypes.append(attribType(l.head, env));
 779         return argtypes.toList();
 780     }
 781 
 782     /** Attribute a type argument list, returning a list of types.
 783      *  Check that all the types are references.
 784      */
 785     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 786         List<Type> types = attribAnyTypes(trees, env);
 787         return chk.checkRefTypes(trees, types);
 788     }
 789 
 790     /**
 791      * Attribute type variables (of generic classes or methods).
 792      * Compound types are attributed later in attribBounds.
 793      * @param typarams the type variables to enter
 794      * @param env      the current environment
 795      */
 796     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 797         for (JCTypeParameter tvar : typarams) {
 798             TypeVar a = (TypeVar)tvar.type;
 799             a.tsym.flags_field |= UNATTRIBUTED;
 800             a.setUpperBound(Type.noType);
 801             if (!tvar.bounds.isEmpty()) {
 802                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 803                 for (JCExpression bound : tvar.bounds.tail)
 804                     bounds = bounds.prepend(attribType(bound, env));
 805                 types.setBounds(a, bounds.reverse());
 806             } else {
 807                 // if no bounds are given, assume a single bound of
 808                 // java.lang.Object.
 809                 types.setBounds(a, List.of(syms.objectType));
 810             }
 811             a.tsym.flags_field &= ~UNATTRIBUTED;
 812         }
 813         if (checkCyclic) {
 814             for (JCTypeParameter tvar : typarams) {
 815                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 816             }
 817         }
 818     }
 819 
 820     /**
 821      * Attribute the type references in a list of annotations.
 822      */
 823     void attribAnnotationTypes(List<JCAnnotation> annotations,
 824                                Env<AttrContext> env) {
 825         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 826             JCAnnotation a = al.head;
 827             attribType(a.annotationType, env);
 828         }
 829     }
 830 
 831     /**
 832      * Attribute a "lazy constant value".
 833      *  @param env         The env for the const value
 834      *  @param variable    The initializer for the const value
 835      *  @param type        The expected type, or null
 836      *  @see VarSymbol#setLazyConstValue
 837      */
 838     public Object attribLazyConstantValue(Env<AttrContext> env,
 839                                       JCVariableDecl variable,
 840                                       Type type) {
 841 
 842         DiagnosticPosition prevLintPos
 843                 = deferredLintHandler.setPos(variable.pos());
 844 
 845         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 846         try {
 847             Type itype = attribExpr(variable.init, env, type);
 848             if (variable.isImplicitlyTyped()) {
 849                 //fixup local variable type
 850                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 851             }
 852             if (itype.constValue() != null) {
 853                 return coerce(itype, type).constValue();
 854             } else {
 855                 return null;
 856             }
 857         } finally {
 858             log.useSource(prevSource);
 859             deferredLintHandler.setPos(prevLintPos);
 860         }
 861     }
 862 
 863     /** Attribute type reference in an `extends' or `implements' clause.
 864      *  Supertypes of anonymous inner classes are usually already attributed.
 865      *
 866      *  @param tree              The tree making up the type reference.
 867      *  @param env               The environment current at the reference.
 868      *  @param classExpected     true if only a class is expected here.
 869      *  @param interfaceExpected true if only an interface is expected here.
 870      */
 871     Type attribBase(JCTree tree,
 872                     Env<AttrContext> env,
 873                     boolean classExpected,
 874                     boolean interfaceExpected,
 875                     boolean checkExtensible) {
 876         Type t = tree.type != null ?
 877             tree.type :
 878             attribType(tree, env);
 879         try {
 880             return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 881         } catch (CompletionFailure ex) {
 882             chk.completionError(tree.pos(), ex);
 883             return t;
 884         }
 885     }
 886     Type checkBase(Type t,
 887                    JCTree tree,
 888                    Env<AttrContext> env,
 889                    boolean classExpected,
 890                    boolean interfaceExpected,
 891                    boolean checkExtensible) {
 892         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 893                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 894         if (t.tsym.isAnonymous()) {
 895             log.error(pos, Errors.CantInheritFromAnon);
 896             return types.createErrorType(t);
 897         }
 898         if (t.isErroneous())
 899             return t;
 900         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 901             // check that type variable is already visible
 902             if (t.getUpperBound() == null) {
 903                 log.error(pos, Errors.IllegalForwardRef);
 904                 return types.createErrorType(t);
 905             }
 906         } else {
 907             t = chk.checkClassType(pos, t, checkExtensible);
 908         }
 909         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 910             log.error(pos, Errors.IntfExpectedHere);
 911             // return errType is necessary since otherwise there might
 912             // be undetected cycles which cause attribution to loop
 913             return types.createErrorType(t);
 914         } else if (checkExtensible &&
 915                    classExpected &&
 916                    (t.tsym.flags() & INTERFACE) != 0) {
 917             log.error(pos, Errors.NoIntfExpectedHere);
 918             return types.createErrorType(t);
 919         }
 920         if (checkExtensible &&
 921             ((t.tsym.flags() & FINAL) != 0)) {
 922             log.error(pos,
 923                       Errors.CantInheritFromFinal(t.tsym));
 924         }
 925         chk.checkNonCyclic(pos, t);
 926         return t;
 927     }
 928 
 929     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 930         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 931         id.type = env.info.scope.owner.enclClass().type;
 932         id.sym = env.info.scope.owner.enclClass();
 933         return id.type;
 934     }
 935 
 936     public void visitClassDef(JCClassDecl tree) {
 937         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 938                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 939                         argumentAttr.withLocalCacheContext() : null);
 940         boolean ctorProloguePrev = env.info.ctorPrologue;
 941         env.info.ctorPrologue = false;
 942         try {
 943             // Local and anonymous classes have not been entered yet, so we need to
 944             // do it now.
 945             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 946                 enter.classEnter(tree, env);
 947             } else {
 948                 // If this class declaration is part of a class level annotation,
 949                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 950                 // order to simplify later steps and allow for sensible error
 951                 // messages.
 952                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 953                     enter.classEnter(tree, env);
 954             }
 955 
 956             ClassSymbol c = tree.sym;
 957             if (c == null) {
 958                 // exit in case something drastic went wrong during enter.
 959                 result = null;
 960             } else {
 961                 // make sure class has been completed:
 962                 c.complete();
 963 
 964                 // If this class appears as an anonymous class in a constructor
 965                 // prologue, disable implicit outer instance from being passed.
 966                 // (This would be an illegal access to "this before super").
 967                 if (ctorProloguePrev && env.tree.hasTag(NEWCLASS)) {
 968                     c.flags_field |= NOOUTERTHIS;
 969                 }
 970                 attribClass(tree.pos(), c);
 971                 result = tree.type = c.type;
 972             }
 973         } finally {
 974             localCacheContext.ifPresent(LocalCacheContext::leave);
 975             env.info.ctorPrologue = ctorProloguePrev;
 976         }
 977     }
 978 
 979     public void visitMethodDef(JCMethodDecl tree) {
 980         MethodSymbol m = tree.sym;
 981         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
 982 
 983         Lint lint = env.info.lint.augment(m);
 984         Lint prevLint = chk.setLint(lint);
 985         boolean ctorProloguePrev = env.info.ctorPrologue;
 986         env.info.ctorPrologue = false;
 987         MethodSymbol prevMethod = chk.setMethod(m);
 988         try {
 989             deferredLintHandler.flush(tree.pos());
 990             chk.checkDeprecatedAnnotation(tree.pos(), m);
 991 
 992 
 993             // Create a new environment with local scope
 994             // for attributing the method.
 995             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
 996             localEnv.info.lint = lint;
 997 
 998             attribStats(tree.typarams, localEnv);
 999 
1000             // If we override any other methods, check that we do so properly.
1001             // JLS ???
1002             if (m.isStatic()) {
1003                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1004             } else {
1005                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1006             }
1007             chk.checkOverride(env, tree, m);
1008 
1009             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1010                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1011             }
1012 
1013             // Enter all type parameters into the local method scope.
1014             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1015                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1016 
1017             ClassSymbol owner = env.enclClass.sym;
1018             if ((owner.flags() & ANNOTATION) != 0 &&
1019                     (tree.params.nonEmpty() ||
1020                     tree.recvparam != null))
1021                 log.error(tree.params.nonEmpty() ?
1022                         tree.params.head.pos() :
1023                         tree.recvparam.pos(),
1024                         Errors.IntfAnnotationMembersCantHaveParams);
1025 
1026             // Attribute all value parameters.
1027             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1028                 attribStat(l.head, localEnv);
1029             }
1030 
1031             chk.checkVarargsMethodDecl(localEnv, tree);
1032 
1033             // Check that type parameters are well-formed.
1034             chk.validate(tree.typarams, localEnv);
1035 
1036             // Check that result type is well-formed.
1037             if (tree.restype != null && !tree.restype.type.hasTag(VOID))
1038                 chk.validate(tree.restype, localEnv);
1039 
1040             // Check that receiver type is well-formed.
1041             if (tree.recvparam != null) {
1042                 // Use a new environment to check the receiver parameter.
1043                 // Otherwise I get "might not have been initialized" errors.
1044                 // Is there a better way?
1045                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1046                 attribType(tree.recvparam, newEnv);
1047                 chk.validate(tree.recvparam, newEnv);
1048             }
1049 
1050             // Is this method a constructor?
1051             boolean isConstructor = TreeInfo.isConstructor(tree);
1052 
1053             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1054                 // lets find if this method is an accessor
1055                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1056                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1057                 if (recordComponent.isPresent()) {
1058                     // the method is a user defined accessor lets check that everything is fine
1059                     if (!tree.sym.isPublic()) {
1060                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1061                     }
1062                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1063                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1064                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1065                     }
1066                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1067                         log.error(tree,
1068                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1069                     }
1070                     if (!tree.typarams.isEmpty()) {
1071                         log.error(tree,
1072                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1073                     }
1074                     if (tree.sym.isStatic()) {
1075                         log.error(tree,
1076                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1077                     }
1078                 }
1079 
1080                 if (isConstructor) {
1081                     // if this a constructor other than the canonical one
1082                     if ((tree.sym.flags_field & RECORD) == 0) {
1083                         if (!TreeInfo.hasConstructorCall(tree, names._this)) {
1084                             log.error(tree, Errors.NonCanonicalConstructorInvokeAnotherConstructor(env.enclClass.sym));
1085                         }
1086                     } else {
1087                         // but if it is the canonical:
1088 
1089                         /* if user generated, then it shouldn't:
1090                          *     - have an accessibility stricter than that of the record type
1091                          *     - explicitly invoke any other constructor
1092                          */
1093                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1094                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1095                                 log.error(tree,
1096                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1097                                             Errors.InvalidCanonicalConstructorInRecord(
1098                                                 Fragments.Canonical,
1099                                                 env.enclClass.sym.name,
1100                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1101                                             ) :
1102                                             Errors.InvalidCanonicalConstructorInRecord(
1103                                                     Fragments.Canonical,
1104                                                     env.enclClass.sym.name,
1105                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1106                                             )
1107                                 );
1108                             }
1109 
1110                             if (TreeInfo.hasAnyConstructorCall(tree)) {
1111                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1112                                         Fragments.Canonical, env.enclClass.sym.name,
1113                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1114                             }
1115                         }
1116 
1117                         // also we want to check that no type variables have been defined
1118                         if (!tree.typarams.isEmpty()) {
1119                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1120                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1121                         }
1122 
1123                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1124                          * record components
1125                          */
1126                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1127                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1128                         for (JCVariableDecl param: tree.params) {
1129                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1130                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1131                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1132                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1133                                         Fragments.Canonical, env.enclClass.sym.name,
1134                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1135                             }
1136                             recordComponents = recordComponents.tail;
1137                             recordFieldTypes = recordFieldTypes.tail;
1138                         }
1139                     }
1140                 }
1141             }
1142 
1143             // annotation method checks
1144             if ((owner.flags() & ANNOTATION) != 0) {
1145                 // annotation method cannot have throws clause
1146                 if (tree.thrown.nonEmpty()) {
1147                     log.error(tree.thrown.head.pos(),
1148                               Errors.ThrowsNotAllowedInIntfAnnotation);
1149                 }
1150                 // annotation method cannot declare type-parameters
1151                 if (tree.typarams.nonEmpty()) {
1152                     log.error(tree.typarams.head.pos(),
1153                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1154                 }
1155                 // validate annotation method's return type (could be an annotation type)
1156                 chk.validateAnnotationType(tree.restype);
1157                 // ensure that annotation method does not clash with members of Object/Annotation
1158                 chk.validateAnnotationMethod(tree.pos(), m);
1159             }
1160 
1161             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1162                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1163 
1164             if (tree.body == null) {
1165                 // Empty bodies are only allowed for
1166                 // abstract, native, or interface methods, or for methods
1167                 // in a retrofit signature class.
1168                 if (tree.defaultValue != null) {
1169                     if ((owner.flags() & ANNOTATION) == 0)
1170                         log.error(tree.pos(),
1171                                   Errors.DefaultAllowedInIntfAnnotationMember);
1172                 }
1173                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1174                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract);
1175             } else {
1176                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1177                     if ((owner.flags() & INTERFACE) != 0) {
1178                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1179                     } else {
1180                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1181                     }
1182                 } else if ((tree.mods.flags & NATIVE) != 0) {
1183                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1184                 }
1185                 // Add an implicit super() call unless an explicit call to
1186                 // super(...) or this(...) is given
1187                 // or we are compiling class java.lang.Object.
1188                 if (isConstructor && owner.type != syms.objectType) {
1189                     if (!TreeInfo.hasAnyConstructorCall(tree)) {
1190                         JCStatement supCall = make.at(tree.body.pos).Exec(make.Apply(List.nil(),
1191                                 make.Ident(names._super), make.Idents(List.nil())));
1192                         tree.body.stats = tree.body.stats.prepend(supCall);




1193                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1194                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1195                             TreeInfo.hasConstructorCall(tree, names._super)) {
1196                         // enum constructors are not allowed to call super
1197                         // directly, so make sure there aren't any super calls
1198                         // in enum constructors, except in the compiler
1199                         // generated one.
1200                         log.error(tree.body.stats.head.pos(),
1201                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1202                     }
1203                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1204                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1205                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1206                         if (!initParamNames.equals(recordComponentNames)) {
1207                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1208                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1209                         }
1210                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1211                             log.error(tree,
1212                                     Errors.InvalidCanonicalConstructorInRecord(
1213                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1214                                             env.enclClass.sym.name,
1215                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1216                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1217                         }
1218                     }
1219                 }
1220 
1221                 // Attribute all type annotations in the body
1222                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m, null);
1223                 annotate.flush();
1224 
1225                 // Start of constructor prologue
1226                 localEnv.info.ctorPrologue = isConstructor;
1227 
1228                 // Attribute method body.
1229                 attribStat(tree.body, localEnv);
1230             }
1231 
1232             localEnv.info.scope.leave();
1233             result = tree.type = m.type;
1234         } finally {
1235             chk.setLint(prevLint);
1236             chk.setMethod(prevMethod);
1237             env.info.ctorPrologue = ctorProloguePrev;
1238         }
1239     }
1240 
1241     public void visitVarDef(JCVariableDecl tree) {
1242         // Local variables have not been entered yet, so we need to do it now:
1243         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1244             if (tree.sym != null) {
1245                 // parameters have already been entered
1246                 env.info.scope.enter(tree.sym);
1247             } else {
1248                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
1249                     if (tree.init == null) {
1250                         //cannot use 'var' without initializer
1251                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1252                         tree.vartype = make.Erroneous();
1253                     } else {
1254                         Fragment msg = canInferLocalVarType(tree);
1255                         if (msg != null) {
1256                             //cannot use 'var' with initializer which require an explicit target
1257                             //(e.g. lambda, method reference, array initializer).
1258                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1259                             tree.vartype = make.Erroneous();
1260                         }
1261                     }
1262                 }
1263                 try {
1264                     annotate.blockAnnotations();
1265                     memberEnter.memberEnter(tree, env);
1266                 } finally {
1267                     annotate.unblockAnnotations();
1268                 }
1269             }
1270         } else {
1271             if (tree.init != null) {
1272                 // Field initializer expression need to be entered.
1273                 annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym, tree.pos());
1274                 annotate.flush();
1275             }
1276         }
1277 
1278         VarSymbol v = tree.sym;
1279         Lint lint = env.info.lint.augment(v);
1280         Lint prevLint = chk.setLint(lint);
1281 
1282         // Check that the variable's declared type is well-formed.
1283         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1284                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1285                 (tree.sym.flags() & PARAMETER) != 0;
1286         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1287 
1288         try {
1289             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1290             deferredLintHandler.flush(tree.pos());
1291             chk.checkDeprecatedAnnotation(tree.pos(), v);
1292 
1293             if (tree.init != null) {
1294                 if ((v.flags_field & FINAL) == 0 ||
1295                     !memberEnter.needsLazyConstValue(tree.init)) {
1296                     // Not a compile-time constant
1297                     // Attribute initializer in a new environment
1298                     // with the declared variable as owner.
1299                     // Check that initializer conforms to variable's declared type.
1300                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
1301                     initEnv.info.lint = lint;
1302                     // In order to catch self-references, we set the variable's
1303                     // declaration position to maximal possible value, effectively
1304                     // marking the variable as undefined.
1305                     initEnv.info.enclVar = v;
1306                     attribExpr(tree.init, initEnv, v.type);
1307                     if (tree.isImplicitlyTyped()) {
1308                         //fixup local variable type
1309                         v.type = chk.checkLocalVarType(tree, tree.init.type, tree.name);
1310                     }
1311                 }
1312                 if (tree.isImplicitlyTyped()) {
1313                     setSyntheticVariableType(tree, v.type);
1314                 }
1315             }
1316             result = tree.type = v.type;
1317             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
1318                 if (isNonArgsMethodInObject(v.name)) {
1319                     log.error(tree, Errors.IllegalRecordComponentName(v));
1320                 }
1321             }
1322         }
1323         finally {
1324             chk.setLint(prevLint);
1325         }
1326     }
1327 
1328     private boolean isNonArgsMethodInObject(Name name) {
1329         for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
1330             if (s.type.getParameterTypes().isEmpty()) {
1331                 return true;
1332             }
1333         }
1334         return false;

1335     }
1336 
1337     Fragment canInferLocalVarType(JCVariableDecl tree) {
1338         LocalInitScanner lis = new LocalInitScanner();
1339         lis.scan(tree.init);
1340         return lis.badInferenceMsg;
1341     }
1342 
1343     static class LocalInitScanner extends TreeScanner {
1344         Fragment badInferenceMsg = null;
1345         boolean needsTarget = true;
1346 
1347         @Override
1348         public void visitNewArray(JCNewArray tree) {
1349             if (tree.elemtype == null && needsTarget) {
1350                 badInferenceMsg = Fragments.LocalArrayMissingTarget;
1351             }
1352         }
1353 
1354         @Override
1355         public void visitLambda(JCLambda tree) {
1356             if (needsTarget) {
1357                 badInferenceMsg = Fragments.LocalLambdaMissingTarget;
1358             }
1359         }
1360 
1361         @Override
1362         public void visitTypeCast(JCTypeCast tree) {
1363             boolean prevNeedsTarget = needsTarget;
1364             try {
1365                 needsTarget = false;
1366                 super.visitTypeCast(tree);
1367             } finally {
1368                 needsTarget = prevNeedsTarget;
1369             }
1370         }
1371 
1372         @Override
1373         public void visitReference(JCMemberReference tree) {
1374             if (needsTarget) {
1375                 badInferenceMsg = Fragments.LocalMrefMissingTarget;
1376             }
1377         }
1378 
1379         @Override
1380         public void visitNewClass(JCNewClass tree) {
1381             boolean prevNeedsTarget = needsTarget;
1382             try {
1383                 needsTarget = false;
1384                 super.visitNewClass(tree);
1385             } finally {
1386                 needsTarget = prevNeedsTarget;
1387             }
1388         }
1389 
1390         @Override
1391         public void visitApply(JCMethodInvocation tree) {
1392             boolean prevNeedsTarget = needsTarget;
1393             try {
1394                 needsTarget = false;
1395                 super.visitApply(tree);
1396             } finally {
1397                 needsTarget = prevNeedsTarget;
1398             }
1399         }
1400     }
1401 
1402     public void visitSkip(JCSkip tree) {
1403         result = null;
1404     }
1405 
1406     public void visitBlock(JCBlock tree) {
1407         if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
1408             // Block is a static or instance initializer;
1409             // let the owner of the environment be a freshly
1410             // created BLOCK-method.
1411             Symbol fakeOwner =
1412                 new MethodSymbol(tree.flags | BLOCK |
1413                     env.info.scope.owner.flags() & STRICTFP, names.empty, null,
1414                     env.info.scope.owner);
1415             final Env<AttrContext> localEnv =
1416                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
1417 
1418             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;




1419             // Attribute all type annotations in the block
1420             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner, null);
1421             annotate.flush();
1422             attribStats(tree.stats, localEnv);
1423 
1424             {
1425                 // Store init and clinit type annotations with the ClassSymbol
1426                 // to allow output in Gen.normalizeDefs.
1427                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1428                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1429                 if ((tree.flags & STATIC) != 0) {
1430                     cs.appendClassInitTypeAttributes(tas);
1431                 } else {
1432                     cs.appendInitTypeAttributes(tas);
1433                 }
1434             }
1435         } else {
1436             // Create a new local environment with a local scope.
1437             Env<AttrContext> localEnv =
1438                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1439             try {
1440                 attribStats(tree.stats, localEnv);
1441             } finally {
1442                 localEnv.info.scope.leave();
1443             }
1444         }
1445         result = null;
1446     }
1447 
1448     public void visitDoLoop(JCDoWhileLoop tree) {
1449         attribStat(tree.body, env.dup(tree));
1450         attribExpr(tree.cond, env, syms.booleanType);
1451         handleLoopConditionBindings(matchBindings, tree, tree.body);
1452         result = null;
1453     }
1454 
1455     public void visitWhileLoop(JCWhileLoop tree) {
1456         attribExpr(tree.cond, env, syms.booleanType);
1457         MatchBindings condBindings = matchBindings;
1458         // include condition's bindings when true in the body:
1459         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1460         try {
1461             attribStat(tree.body, whileEnv.dup(tree));
1462         } finally {
1463             whileEnv.info.scope.leave();
1464         }
1465         handleLoopConditionBindings(condBindings, tree, tree.body);
1466         result = null;
1467     }
1468 
1469     public void visitForLoop(JCForLoop tree) {
1470         Env<AttrContext> loopEnv =
1471             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1472         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1473         try {
1474             attribStats(tree.init, loopEnv);
1475             if (tree.cond != null) {
1476                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1477                 // include condition's bindings when true in the body and step:
1478                 condBindings = matchBindings;
1479             }
1480             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1481             try {
1482                 bodyEnv.tree = tree; // before, we were not in loop!
1483                 attribStats(tree.step, bodyEnv);
1484                 attribStat(tree.body, bodyEnv);
1485             } finally {
1486                 bodyEnv.info.scope.leave();
1487             }
1488             result = null;
1489         }
1490         finally {
1491             loopEnv.info.scope.leave();
1492         }
1493         handleLoopConditionBindings(condBindings, tree, tree.body);
1494     }
1495 
1496     /**
1497      * Include condition's bindings when false after the loop, if cannot get out of the loop
1498      */
1499     private void handleLoopConditionBindings(MatchBindings condBindings,
1500                                              JCStatement loop,
1501                                              JCStatement loopBody) {
1502         if (condBindings.bindingsWhenFalse.nonEmpty() &&
1503             !breaksTo(env, loop, loopBody)) {
1504             addBindings2Scope(loop, condBindings.bindingsWhenFalse);
1505         }
1506     }
1507 
1508     private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
1509         preFlow(body);
1510         return flow.breaksToTree(env, loop, body, make);
1511     }
1512 
1513     /**
1514      * Add given bindings to the current scope, unless there's a break to
1515      * an immediately enclosing labeled statement.
1516      */
1517     private void addBindings2Scope(JCStatement introducingStatement,
1518                                    List<BindingSymbol> bindings) {
1519         if (bindings.isEmpty()) {
1520             return ;
1521         }
1522 
1523         var searchEnv = env;
1524         while (searchEnv.tree instanceof JCLabeledStatement labeled &&
1525                labeled.body == introducingStatement) {
1526             if (breaksTo(env, labeled, labeled.body)) {
1527                 //breaking to an immediately enclosing labeled statement
1528                 return ;
1529             }
1530             searchEnv = searchEnv.next;
1531             introducingStatement = labeled;
1532         }
1533 
1534         //include condition's body when false after the while, if cannot get out of the loop
1535         bindings.forEach(env.info.scope::enter);
1536         bindings.forEach(BindingSymbol::preserveBinding);
1537     }
1538 
1539     public void visitForeachLoop(JCEnhancedForLoop tree) {
1540         Env<AttrContext> loopEnv =
1541             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1542         try {
1543             //the Formal Parameter of a for-each loop is not in the scope when
1544             //attributing the for-each expression; we mimic this by attributing
1545             //the for-each expression first (against original scope).
1546             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1547             chk.checkNonVoid(tree.pos(), exprType);
1548             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1549             if (elemtype == null) {
1550                 // or perhaps expr implements Iterable<T>?
1551                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1552                 if (base == null) {
1553                     log.error(tree.expr.pos(),
1554                               Errors.ForeachNotApplicableToType(exprType,
1555                                                                 Fragments.TypeReqArrayOrIterable));
1556                     elemtype = types.createErrorType(exprType);
1557                 } else {
1558                     List<Type> iterableParams = base.allparams();
1559                     elemtype = iterableParams.isEmpty()
1560                         ? syms.objectType
1561                         : types.wildUpperBound(iterableParams.head);
1562 
1563                     // Check the return type of the method iterator().
1564                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1565                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1566                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1567                     if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
1568                         log.error(tree.pos(),
1569                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1570                     }
1571                 }
1572             }
1573             if (tree.var.isImplicitlyTyped()) {
1574                 Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
1575                 setSyntheticVariableType(tree.var, inferredType);
1576             }
1577             attribStat(tree.var, loopEnv);
1578             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1579             loopEnv.tree = tree; // before, we were not in loop!
1580             attribStat(tree.body, loopEnv);
1581             result = null;
1582         }
1583         finally {
1584             loopEnv.info.scope.leave();
1585         }
1586     }
1587 
1588     public void visitLabelled(JCLabeledStatement tree) {
1589         // Check that label is not used in an enclosing statement
1590         Env<AttrContext> env1 = env;
1591         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1592             if (env1.tree.hasTag(LABELLED) &&
1593                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1594                 log.error(tree.pos(),
1595                           Errors.LabelAlreadyInUse(tree.label));
1596                 break;
1597             }
1598             env1 = env1.next;
1599         }
1600 
1601         attribStat(tree.body, env.dup(tree));
1602         result = null;
1603     }
1604 
1605     public void visitSwitch(JCSwitch tree) {
1606         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1607             attribStats(c.stats, caseEnv);
1608         });
1609         result = null;
1610     }
1611 
1612     public void visitSwitchExpression(JCSwitchExpression tree) {
1613         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
1614                 PolyKind.STANDALONE : PolyKind.POLY;
1615 
1616         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
1617             //this means we are returning a poly conditional from void-compatible lambda expression
1618             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
1619             result = tree.type = types.createErrorType(resultInfo.pt);
1620             return;
1621         }
1622 
1623         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
1624                 unknownExprInfo :
1625                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
1626 
1627         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
1628         ListBuffer<Type> caseTypes = new ListBuffer<>();
1629 
1630         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1631             caseEnv.info.yieldResult = condInfo;
1632             attribStats(c.stats, caseEnv);
1633             new TreeScanner() {
1634                 @Override
1635                 public void visitYield(JCYield brk) {
1636                     if (brk.target == tree) {
1637                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
1638                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
1639                     }
1640                     super.visitYield(brk);
1641                 }
1642 
1643                 @Override public void visitClassDef(JCClassDecl tree) {}
1644                 @Override public void visitLambda(JCLambda tree) {}
1645             }.scan(c.stats);
1646         });
1647 
1648         if (tree.cases.isEmpty()) {
1649             log.error(tree.pos(),
1650                       Errors.SwitchExpressionEmpty);
1651         } else if (caseTypes.isEmpty()) {
1652             log.error(tree.pos(),
1653                       Errors.SwitchExpressionNoResultExpressions);
1654         }
1655 
1656         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
1657 
1658         result = tree.type = check(tree, owntype, KindSelector.VAL, resultInfo);
1659     }
1660     //where:
1661         CheckContext switchExpressionContext(CheckContext checkContext) {
1662             return new Check.NestedCheckContext(checkContext) {
1663                 //this will use enclosing check context to check compatibility of
1664                 //subexpression against target type; if we are in a method check context,
1665                 //depending on whether boxing is allowed, we could have incompatibilities
1666                 @Override
1667                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1668                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
1669                 }
1670             };
1671         }
1672 
1673     private void handleSwitch(JCTree switchTree,
1674                               JCExpression selector,
1675                               List<JCCase> cases,
1676                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
1677         Type seltype = attribExpr(selector, env);
1678 
1679         Env<AttrContext> switchEnv =
1680             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
1681 
1682         try {
1683             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
1684             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
1685             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
1686             boolean intSwitch = types.isAssignable(seltype, syms.intType);
1687             boolean errorPrimitiveSwitch = seltype.isPrimitive() && !intSwitch;
1688             boolean patternSwitch;
1689             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
1690                 !intSwitch && !errorPrimitiveSwitch) {
1691                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
1692                 patternSwitch = true;
1693             } else {
1694                 if (errorPrimitiveSwitch) {
1695                     log.error(selector.pos(), Errors.SelectorTypeNotAllowed(seltype));
1696                 }
1697                 patternSwitch = cases.stream()
1698                                      .flatMap(c -> c.labels.stream())
1699                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
1700                                                     TreeInfo.isNullCaseLabel(l));
1701             }
1702 
1703             // Attribute all cases and
1704             // check that there are no duplicate case labels or default clauses.
1705             Set<Object> constants = new HashSet<>(); // The set of case constants.
1706             boolean hasDefault = false;           // Is there a default label?
1707             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
1708             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
1709             boolean hasNullPattern = false;       // Is there a null pattern?
1710             CaseTree.CaseKind caseKind = null;
1711             boolean wasError = false;
1712             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
1713                 JCCase c = l.head;
1714                 if (caseKind == null) {
1715                     caseKind = c.caseKind;
1716                 } else if (caseKind != c.caseKind && !wasError) {
1717                     log.error(c.pos(),
1718                               Errors.SwitchMixingCaseTypes);
1719                     wasError = true;
1720                 }
1721                 MatchBindings currentBindings = null;
1722                 MatchBindings guardBindings = null;
1723                 for (List<JCCaseLabel> labels = c.labels; labels.nonEmpty(); labels = labels.tail) {
1724                     JCCaseLabel label = labels.head;
1725                     if (label instanceof JCConstantCaseLabel constLabel) {
1726                         JCExpression expr = constLabel.expr;
1727                         if (TreeInfo.isNull(expr)) {
1728                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
1729                             if (hasNullPattern) {
1730                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1731                             }
1732                             hasNullPattern = true;
1733                             attribExpr(expr, switchEnv, seltype);
1734                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
1735                         } else if (enumSwitch) {
1736                             Symbol sym = enumConstant(expr, seltype);
1737                             if (sym == null) {
1738                                 if (allowPatternSwitch) {
1739                                     attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1740                                     Symbol enumSym = TreeInfo.symbol(expr);
1741                                     if (enumSym == null || !enumSym.isEnum() || enumSym.kind != VAR) {
1742                                         log.error(expr.pos(), Errors.EnumLabelMustBeEnumConstant);
1743                                     } else if (!constants.add(enumSym)) {
1744                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1745                                     }
1746                                 } else {
1747                                     log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
1748                                 }
1749                             } else if (!constants.add(sym)) {
1750                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1751                             }
1752                         } else if (errorEnumSwitch) {
1753                             //error recovery: the selector is erroneous, and all the case labels
1754                             //are identifiers. This could be an enum switch - don't report resolve
1755                             //error for the case label:
1756                             var prevResolveHelper = rs.basicLogResolveHelper;
1757                             try {
1758                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
1759                                 attribExpr(expr, switchEnv, seltype);
1760                             } finally {
1761                                 rs.basicLogResolveHelper = prevResolveHelper;
1762                             }
1763                         } else {
1764                             Type pattype = attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1765                             if (!pattype.hasTag(ERROR)) {
1766                                 if (pattype.constValue() == null) {
1767                                     Symbol s = TreeInfo.symbol(expr);
1768                                     if (s != null && s.kind == TYP) {
1769                                         log.error(expr.pos(),
1770                                                   Errors.PatternExpected);
1771                                     } else if (s == null || !s.isEnum()) {
1772                                         log.error(expr.pos(),
1773                                                   (stringSwitch ? Errors.StringConstReq
1774                                                                 : intSwitch ? Errors.ConstExprReq
1775                                                                             : Errors.PatternOrEnumReq));
1776                                     } else if (!constants.add(s)) {
1777                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1778                                     }
1779                                 } else if (!stringSwitch && !intSwitch && !errorPrimitiveSwitch) {
1780                                     log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
1781                                 } else if (!constants.add(pattype.constValue())) {
1782                                     log.error(c.pos(), Errors.DuplicateCaseLabel);
1783                                 }
1784                             }
1785                         }
1786                     } else if (label instanceof JCDefaultCaseLabel def) {
1787                         if (hasDefault) {
1788                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
1789                         } else if (hasUnconditionalPattern) {
1790                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
1791                         }
1792                         hasDefault = true;
1793                         matchBindings = MatchBindingsComputer.EMPTY;
1794                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
1795                         //pattern
1796                         JCPattern pat = patternlabel.pat;
1797                         attribExpr(pat, switchEnv, seltype);
1798                         Type primaryType = TreeInfo.primaryPatternType(pat);
1799                         if (!primaryType.hasTag(TYPEVAR)) {
1800                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
1801                         }
1802                         if (!errorPrimitiveSwitch) {
1803                             checkCastablePattern(pat.pos(), seltype, primaryType);
1804                         }
1805                         Type patternType = types.erasure(primaryType);
1806                         JCExpression guard = c.guard;
1807                         if (guardBindings == null && guard != null) {
1808                             MatchBindings afterPattern = matchBindings;
1809                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
1810                             try {
1811                                 attribExpr(guard, bodyEnv, syms.booleanType);
1812                             } finally {
1813                                 bodyEnv.info.scope.leave();
1814                             }
1815 
1816                             guardBindings = matchBindings;
1817                             matchBindings = afterPattern;
1818 
1819                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
1820                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
1821                             }
1822                         }
1823                         boolean unguarded = TreeInfo.unguardedCase(c) && !pat.hasTag(RECORDPATTERN);
1824                         boolean unconditional =
1825                                 unguarded &&
1826                                 !patternType.isErroneous() &&
1827                                 types.isSubtype(types.boxedTypeOrType(types.erasure(seltype)),
1828                                                 patternType);
1829                         if (unconditional) {
1830                             if (hasUnconditionalPattern) {
1831                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
1832                             } else if (hasDefault) {
1833                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
1834                             }
1835                             hasUnconditionalPattern = true;
1836                         }
1837                         lastPatternErroneous = patternType.isErroneous();
1838                     } else {
1839                         Assert.error();
1840                     }
1841                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
1842                 }
1843 
1844                 if (guardBindings != null) {
1845                     currentBindings = matchBindingsComputer.caseGuard(c, currentBindings, guardBindings);
1846                 }
1847 
1848                 Env<AttrContext> caseEnv =
1849                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
1850                 try {
1851                     attribCase.accept(c, caseEnv);
1852                 } finally {
1853                     caseEnv.info.scope.leave();
1854                 }
1855                 addVars(c.stats, switchEnv.info.scope);
1856 
1857                 preFlow(c);
1858                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
1859             }
1860             if (patternSwitch) {
1861                 chk.checkSwitchCaseStructure(cases);
1862                 chk.checkSwitchCaseLabelDominated(cases);
1863             }
1864             if (switchTree.hasTag(SWITCH)) {
1865                 ((JCSwitch) switchTree).hasUnconditionalPattern =
1866                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1867                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
1868             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
1869                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
1870                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1871                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
1872             } else {
1873                 Assert.error(switchTree.getTag().name());
1874             }
1875         } finally {
1876             switchEnv.info.scope.leave();
1877         }
1878     }
1879     // where
1880         private ResultInfo caseLabelResultInfo(Type seltype) {
1881             return new ResultInfo(KindSelector.VAL_TYP,
1882                                   !seltype.hasTag(ERROR) ? seltype
1883                                                          : Type.noType);
1884         }
1885         /** Add any variables defined in stats to the switch scope. */
1886         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
1887             for (;stats.nonEmpty(); stats = stats.tail) {
1888                 JCTree stat = stats.head;
1889                 if (stat.hasTag(VARDEF))
1890                     switchScope.enter(((JCVariableDecl) stat).sym);
1891             }
1892         }
1893     // where
1894     /** Return the selected enumeration constant symbol, or null. */
1895     private Symbol enumConstant(JCTree tree, Type enumType) {
1896         if (tree.hasTag(IDENT)) {
1897             JCIdent ident = (JCIdent)tree;
1898             Name name = ident.name;
1899             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
1900                 if (sym.kind == VAR) {
1901                     Symbol s = ident.sym = sym;
1902                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1903                     ident.type = s.type;
1904                     return ((s.flags_field & Flags.ENUM) == 0)
1905                         ? null : s;
1906                 }
1907             }
1908         }
1909         return null;
1910     }
1911 
1912     public void visitSynchronized(JCSynchronized tree) {
1913         chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
1914         if (env.info.lint.isEnabled(LintCategory.SYNCHRONIZATION) && isValueBased(tree.lock.type)) {
1915             log.warning(LintCategory.SYNCHRONIZATION, tree.pos(), Warnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
1916         }
1917         attribStat(tree.body, env);
1918         result = null;
1919     }
1920         // where
1921         private boolean isValueBased(Type t) {
1922             return t != null && t.tsym != null && (t.tsym.flags() & VALUE_BASED) != 0;
1923         }
1924 
1925 
1926     public void visitTry(JCTry tree) {
1927         // Create a new local environment with a local
1928         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1929         try {
1930             boolean isTryWithResource = tree.resources.nonEmpty();
1931             // Create a nested environment for attributing the try block if needed
1932             Env<AttrContext> tryEnv = isTryWithResource ?
1933                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1934                 localEnv;
1935             try {
1936                 // Attribute resource declarations
1937                 for (JCTree resource : tree.resources) {
1938                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
1939                         @Override
1940                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
1941                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
1942                         }
1943                     };
1944                     ResultInfo twrResult =
1945                         new ResultInfo(KindSelector.VAR,
1946                                        syms.autoCloseableType,
1947                                        twrContext);
1948                     if (resource.hasTag(VARDEF)) {
1949                         attribStat(resource, tryEnv);
1950                         twrResult.check(resource, resource.type);
1951 
1952                         //check that resource type cannot throw InterruptedException
1953                         checkAutoCloseable(resource.pos(), localEnv, resource.type);
1954 
1955                         VarSymbol var = ((JCVariableDecl) resource).sym;
1956 
1957                         var.flags_field |= Flags.FINAL;
1958                         var.setData(ElementKind.RESOURCE_VARIABLE);
1959                     } else {
1960                         attribTree(resource, tryEnv, twrResult);
1961                     }
1962                 }
1963                 // Attribute body
1964                 attribStat(tree.body, tryEnv);
1965             } finally {
1966                 if (isTryWithResource)
1967                     tryEnv.info.scope.leave();
1968             }
1969 
1970             // Attribute catch clauses
1971             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
1972                 JCCatch c = l.head;
1973                 Env<AttrContext> catchEnv =
1974                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
1975                 try {
1976                     Type ctype = attribStat(c.param, catchEnv);
1977                     if (TreeInfo.isMultiCatch(c)) {
1978                         //multi-catch parameter is implicitly marked as final
1979                         c.param.sym.flags_field |= FINAL | UNION;
1980                     }
1981                     if (c.param.sym.kind == VAR) {
1982                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
1983                     }
1984                     chk.checkType(c.param.vartype.pos(),
1985                                   chk.checkClassType(c.param.vartype.pos(), ctype),
1986                                   syms.throwableType);
1987                     attribStat(c.body, catchEnv);
1988                 } finally {
1989                     catchEnv.info.scope.leave();
1990                 }
1991             }
1992 
1993             // Attribute finalizer
1994             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
1995             result = null;
1996         }
1997         finally {
1998             localEnv.info.scope.leave();
1999         }
2000     }
2001 
2002     void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
2003         if (!resource.isErroneous() &&
2004             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
2005             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
2006             Symbol close = syms.noSymbol;
2007             Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log);
2008             try {
2009                 close = rs.resolveQualifiedMethod(pos,
2010                         env,
2011                         types.skipTypeVars(resource, false),
2012                         names.close,
2013                         List.nil(),
2014                         List.nil());
2015             }
2016             finally {
2017                 log.popDiagnosticHandler(discardHandler);
2018             }
2019             if (close.kind == MTH &&
2020                     close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
2021                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
2022                     env.info.lint.isEnabled(LintCategory.TRY)) {
2023                 log.warning(LintCategory.TRY, pos, Warnings.TryResourceThrowsInterruptedExc(resource));
2024             }
2025         }
2026     }
2027 
2028     public void visitConditional(JCConditional tree) {
2029         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2030         MatchBindings condBindings = matchBindings;
2031 
2032         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2033                 isBooleanOrNumeric(env, tree)) ?
2034                 PolyKind.STANDALONE : PolyKind.POLY;
2035 
2036         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2037             //this means we are returning a poly conditional from void-compatible lambda expression
2038             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2039             result = tree.type = types.createErrorType(resultInfo.pt);
2040             return;
2041         }
2042 
2043         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2044                 unknownExprInfo :
2045                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2046 
2047 
2048         // x ? y : z
2049         // include x's bindings when true in y
2050         // include x's bindings when false in z
2051 
2052         Type truetype;
2053         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2054         try {
2055             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2056         } finally {
2057             trueEnv.info.scope.leave();
2058         }
2059 
2060         MatchBindings trueBindings = matchBindings;
2061 
2062         Type falsetype;
2063         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2064         try {
2065             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2066         } finally {
2067             falseEnv.info.scope.leave();
2068         }
2069 
2070         MatchBindings falseBindings = matchBindings;
2071 
2072         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2073                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2074                          List.of(truetype, falsetype)) : pt();
2075         if (condtype.constValue() != null &&
2076                 truetype.constValue() != null &&
2077                 falsetype.constValue() != null &&
2078                 !owntype.hasTag(NONE)) {
2079             //constant folding
2080             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2081         }
2082         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2083         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2084     }
2085     //where
2086         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2087             switch (tree.getTag()) {
2088                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2089                               ((JCLiteral)tree).typetag == BOOLEAN ||
2090                               ((JCLiteral)tree).typetag == BOT;
2091                 case LAMBDA: case REFERENCE: return false;
2092                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2093                 case CONDEXPR:
2094                     JCConditional condTree = (JCConditional)tree;
2095                     return isBooleanOrNumeric(env, condTree.truepart) &&
2096                             isBooleanOrNumeric(env, condTree.falsepart);
2097                 case APPLY:
2098                     JCMethodInvocation speculativeMethodTree =
2099                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2100                                     tree, env, unknownExprInfo,
2101                                     argumentAttr.withLocalCacheContext());
2102                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2103                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2104                             env.enclClass.type :
2105                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2106                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2107                     return primitiveOrBoxed(owntype);
2108                 case NEWCLASS:
2109                     JCExpression className =
2110                             removeClassParams.translate(((JCNewClass)tree).clazz);
2111                     JCExpression speculativeNewClassTree =
2112                             (JCExpression)deferredAttr.attribSpeculative(
2113                                     className, env, unknownTypeInfo,
2114                                     argumentAttr.withLocalCacheContext());
2115                     return primitiveOrBoxed(speculativeNewClassTree.type);
2116                 default:
2117                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2118                             argumentAttr.withLocalCacheContext()).type;
2119                     return primitiveOrBoxed(speculativeType);
2120             }
2121         }
2122         //where
2123             boolean primitiveOrBoxed(Type t) {
2124                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2125             }
2126 
2127             TreeTranslator removeClassParams = new TreeTranslator() {
2128                 @Override
2129                 public void visitTypeApply(JCTypeApply tree) {
2130                     result = translate(tree.clazz);
2131                 }
2132             };
2133 
2134         CheckContext conditionalContext(CheckContext checkContext) {
2135             return new Check.NestedCheckContext(checkContext) {
2136                 //this will use enclosing check context to check compatibility of
2137                 //subexpression against target type; if we are in a method check context,
2138                 //depending on whether boxing is allowed, we could have incompatibilities
2139                 @Override
2140                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2141                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2142                 }
2143             };
2144         }
2145 
2146         /** Compute the type of a conditional expression, after
2147          *  checking that it exists.  See JLS 15.25. Does not take into
2148          *  account the special case where condition and both arms
2149          *  are constants.
2150          *
2151          *  @param pos      The source position to be used for error
2152          *                  diagnostics.
2153          *  @param thentype The type of the expression's then-part.
2154          *  @param elsetype The type of the expression's else-part.
2155          */
2156         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2157             if (condTypes.isEmpty()) {
2158                 return syms.objectType; //TODO: how to handle?
2159             }
2160             Type first = condTypes.head;
2161             // If same type, that is the result
2162             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2163                 return first.baseType();
2164 
2165             List<Type> unboxedTypes = condTypes.stream()
2166                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2167                                                .collect(List.collector());
2168 
2169             // Otherwise, if both arms can be converted to a numeric
2170             // type, return the least numeric type that fits both arms
2171             // (i.e. return larger of the two, or return int if one
2172             // arm is short, the other is char).
2173             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2174                 // If one arm has an integer subrange type (i.e., byte,
2175                 // short, or char), and the other is an integer constant
2176                 // that fits into the subrange, return the subrange type.
2177                 for (Type type : unboxedTypes) {
2178                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2179                         continue;
2180                     }
2181                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2182                         return type.baseType();
2183                 }
2184 
2185                 for (TypeTag tag : primitiveTags) {
2186                     Type candidate = syms.typeOfTag[tag.ordinal()];
2187                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2188                         return candidate;
2189                     }
2190                 }
2191             }
2192 
2193             // Those were all the cases that could result in a primitive
2194             condTypes = condTypes.stream()
2195                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
2196                                  .collect(List.collector());
2197 
2198             for (Type type : condTypes) {
2199                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2200                     return type.baseType();
2201             }
2202 
2203             Iterator<DiagnosticPosition> posIt = positions.iterator();
2204 
2205             condTypes = condTypes.stream()
2206                                  .map(t -> chk.checkNonVoid(posIt.next(), t))
2207                                  .collect(List.collector());
2208 
2209             // both are known to be reference types.  The result is
2210             // lub(thentype,elsetype). This cannot fail, as it will
2211             // always be possible to infer "Object" if nothing better.
2212             return types.lub(condTypes.stream()
2213                         .map(t -> t.baseType())
2214                         .filter(t -> !t.hasTag(BOT))
2215                         .collect(List.collector()));
2216         }
2217 
2218     static final TypeTag[] primitiveTags = new TypeTag[]{
2219         BYTE,
2220         CHAR,
2221         SHORT,
2222         INT,
2223         LONG,
2224         FLOAT,
2225         DOUBLE,
2226         BOOLEAN,
2227     };
2228 
2229     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2230         return bindingEnv(env, env.tree, bindings);
2231     }
2232 
2233     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2234         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2235         bindings.forEach(env1.info.scope::enter);
2236         return env1;
2237     }
2238 
2239     public void visitIf(JCIf tree) {
2240         attribExpr(tree.cond, env, syms.booleanType);
2241 
2242         // if (x) { y } [ else z ]
2243         // include x's bindings when true in y
2244         // include x's bindings when false in z
2245 
2246         MatchBindings condBindings = matchBindings;
2247         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2248 
2249         try {
2250             attribStat(tree.thenpart, thenEnv);
2251         } finally {
2252             thenEnv.info.scope.leave();
2253         }
2254 
2255         preFlow(tree.thenpart);
2256         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2257         boolean aliveAfterElse;
2258 
2259         if (tree.elsepart != null) {
2260             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2261             try {
2262                 attribStat(tree.elsepart, elseEnv);
2263             } finally {
2264                 elseEnv.info.scope.leave();
2265             }
2266             preFlow(tree.elsepart);
2267             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2268         } else {
2269             aliveAfterElse = true;
2270         }
2271 
2272         chk.checkEmptyIf(tree);
2273 
2274         List<BindingSymbol> afterIfBindings = List.nil();
2275 
2276         if (aliveAfterThen && !aliveAfterElse) {
2277             afterIfBindings = condBindings.bindingsWhenTrue;
2278         } else if (aliveAfterElse && !aliveAfterThen) {
2279             afterIfBindings = condBindings.bindingsWhenFalse;
2280         }
2281 
2282         addBindings2Scope(tree, afterIfBindings);
2283 
2284         result = null;
2285     }
2286 
2287         void preFlow(JCTree tree) {
2288             attrRecover.doRecovery();
2289             new PostAttrAnalyzer() {
2290                 @Override
2291                 public void scan(JCTree tree) {
2292                     if (tree == null ||
2293                             (tree.type != null &&
2294                             tree.type == Type.stuckType)) {
2295                         //don't touch stuck expressions!
2296                         return;
2297                     }
2298                     super.scan(tree);
2299                 }
2300 
2301                 @Override
2302                 public void visitClassDef(JCClassDecl that) {
2303                     if (that.sym != null) {
2304                         // Method preFlow shouldn't visit class definitions
2305                         // that have not been entered and attributed.
2306                         // See JDK-8254557 and JDK-8203277 for more details.
2307                         super.visitClassDef(that);
2308                     }
2309                 }
2310 
2311                 @Override
2312                 public void visitLambda(JCLambda that) {
2313                     if (that.type != null) {
2314                         // Method preFlow shouldn't visit lambda expressions
2315                         // that have not been entered and attributed.
2316                         // See JDK-8254557 and JDK-8203277 for more details.
2317                         super.visitLambda(that);
2318                     }
2319                 }
2320             }.scan(tree);
2321         }
2322 
2323     public void visitExec(JCExpressionStatement tree) {
2324         //a fresh environment is required for 292 inference to work properly ---
2325         //see Infer.instantiatePolymorphicSignatureInstance()
2326         Env<AttrContext> localEnv = env.dup(tree);
2327         attribExpr(tree.expr, localEnv);
2328         result = null;
2329     }
2330 
2331     public void visitBreak(JCBreak tree) {
2332         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2333         result = null;
2334     }
2335 
2336     public void visitYield(JCYield tree) {
2337         if (env.info.yieldResult != null) {
2338             attribTree(tree.value, env, env.info.yieldResult);
2339             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2340         } else {
2341             log.error(tree.pos(), tree.value.hasTag(PARENS)
2342                     ? Errors.NoSwitchExpressionQualify
2343                     : Errors.NoSwitchExpression);
2344             attribTree(tree.value, env, unknownExprInfo);
2345         }
2346         result = null;
2347     }
2348 
2349     public void visitContinue(JCContinue tree) {
2350         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2351         result = null;
2352     }
2353     //where
2354         /** Return the target of a break, continue or yield statement,
2355          *  if it exists, report an error if not.
2356          *  Note: The target of a labelled break or continue is the
2357          *  (non-labelled) statement tree referred to by the label,
2358          *  not the tree representing the labelled statement itself.
2359          *
2360          *  @param pos     The position to be used for error diagnostics
2361          *  @param tag     The tag of the jump statement. This is either
2362          *                 Tree.BREAK or Tree.CONTINUE.
2363          *  @param label   The label of the jump statement, or null if no
2364          *                 label is given.
2365          *  @param env     The environment current at the jump statement.
2366          */
2367         private JCTree findJumpTarget(DiagnosticPosition pos,
2368                                                    JCTree.Tag tag,
2369                                                    Name label,
2370                                                    Env<AttrContext> env) {
2371             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2372 
2373             if (jumpTarget.snd != null) {
2374                 log.error(pos, jumpTarget.snd);
2375             }
2376 
2377             return jumpTarget.fst;
2378         }
2379         /** Return the target of a break or continue statement, if it exists,
2380          *  report an error if not.
2381          *  Note: The target of a labelled break or continue is the
2382          *  (non-labelled) statement tree referred to by the label,
2383          *  not the tree representing the labelled statement itself.
2384          *
2385          *  @param tag     The tag of the jump statement. This is either
2386          *                 Tree.BREAK or Tree.CONTINUE.
2387          *  @param label   The label of the jump statement, or null if no
2388          *                 label is given.
2389          *  @param env     The environment current at the jump statement.
2390          */
2391         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2392                                                                        Name label,
2393                                                                        Env<AttrContext> env) {
2394             // Search environments outwards from the point of jump.
2395             Env<AttrContext> env1 = env;
2396             JCDiagnostic.Error pendingError = null;
2397             LOOP:
2398             while (env1 != null) {
2399                 switch (env1.tree.getTag()) {
2400                     case LABELLED:
2401                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2402                         if (label == labelled.label) {
2403                             // If jump is a continue, check that target is a loop.
2404                             if (tag == CONTINUE) {
2405                                 if (!labelled.body.hasTag(DOLOOP) &&
2406                                         !labelled.body.hasTag(WHILELOOP) &&
2407                                         !labelled.body.hasTag(FORLOOP) &&
2408                                         !labelled.body.hasTag(FOREACHLOOP)) {
2409                                     pendingError = Errors.NotLoopLabel(label);
2410                                 }
2411                                 // Found labelled statement target, now go inwards
2412                                 // to next non-labelled tree.
2413                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2414                             } else {
2415                                 return Pair.of(labelled, pendingError);
2416                             }
2417                         }
2418                         break;
2419                     case DOLOOP:
2420                     case WHILELOOP:
2421                     case FORLOOP:
2422                     case FOREACHLOOP:
2423                         if (label == null) return Pair.of(env1.tree, pendingError);
2424                         break;
2425                     case SWITCH:
2426                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2427                         break;
2428                     case SWITCH_EXPRESSION:
2429                         if (tag == YIELD) {
2430                             return Pair.of(env1.tree, null);
2431                         } else if (tag == BREAK) {
2432                             pendingError = Errors.BreakOutsideSwitchExpression;
2433                         } else {
2434                             pendingError = Errors.ContinueOutsideSwitchExpression;
2435                         }
2436                         break;
2437                     case LAMBDA:
2438                     case METHODDEF:
2439                     case CLASSDEF:
2440                         break LOOP;
2441                     default:
2442                 }
2443                 env1 = env1.next;
2444             }
2445             if (label != null)
2446                 return Pair.of(null, Errors.UndefLabel(label));
2447             else if (pendingError != null)
2448                 return Pair.of(null, pendingError);
2449             else if (tag == CONTINUE)
2450                 return Pair.of(null, Errors.ContOutsideLoop);
2451             else
2452                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2453         }
2454 
2455     public void visitReturn(JCReturn tree) {
2456         // Check that there is an enclosing method which is
2457         // nested within than the enclosing class.
2458         if (env.info.returnResult == null) {
2459             log.error(tree.pos(), Errors.RetOutsideMeth);
2460         } else if (env.info.yieldResult != null) {
2461             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2462         } else if (!env.info.isLambda &&
2463                 !env.info.isNewClass &&
2464                 env.enclMethod != null &&
2465                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2466             log.error(env.enclMethod,
2467                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2468         } else {
2469             // Attribute return expression, if it exists, and check that
2470             // it conforms to result type of enclosing method.
2471             if (tree.expr != null) {
2472                 if (env.info.returnResult.pt.hasTag(VOID)) {
2473                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2474                               diags.fragment(Fragments.UnexpectedRetVal));
2475                 }
2476                 attribTree(tree.expr, env, env.info.returnResult);
2477             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2478                     !env.info.returnResult.pt.hasTag(NONE)) {
2479                 env.info.returnResult.checkContext.report(tree.pos(),
2480                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2481             }
2482         }
2483         result = null;
2484     }
2485 
2486     public void visitThrow(JCThrow tree) {
2487         Type owntype = attribExpr(tree.expr, env, Type.noType);
2488         chk.checkType(tree, owntype, syms.throwableType);
2489         result = null;
2490     }
2491 
2492     public void visitAssert(JCAssert tree) {
2493         attribExpr(tree.cond, env, syms.booleanType);
2494         if (tree.detail != null) {
2495             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2496         }
2497         result = null;
2498     }
2499 
2500      /** Visitor method for method invocations.
2501      *  NOTE: The method part of an application will have in its type field
2502      *        the return type of the method, not the method's type itself!
2503      */
2504     public void visitApply(JCMethodInvocation tree) {
2505         // The local environment of a method application is
2506         // a new environment nested in the current one.
2507         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2508 
2509         // The types of the actual method arguments.
2510         List<Type> argtypes;
2511 
2512         // The types of the actual method type arguments.
2513         List<Type> typeargtypes = null;
2514 
2515         Name methName = TreeInfo.name(tree.meth);
2516 
2517         boolean isConstructorCall =
2518             methName == names._this || methName == names._super;
2519 
2520         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2521         if (isConstructorCall) {
2522 
2523             // Attribute arguments, yielding list of argument types.
2524             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2525             argtypes = argtypesBuf.toList();
2526             typeargtypes = attribTypes(tree.typeargs, localEnv);
2527 
2528             // Done with this()/super() parameters. End of constructor prologue.
2529             env.info.ctorPrologue = false;
2530 
2531             // Variable `site' points to the class in which the called
2532             // constructor is defined.
2533             Type site = env.enclClass.sym.type;
2534             if (methName == names._super) {
2535                 if (site == syms.objectType) {
2536                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2537                     site = types.createErrorType(syms.objectType);
2538                 } else {
2539                     site = types.supertype(site);
2540                 }
2541             }
2542 
2543             if (site.hasTag(CLASS)) {
2544                 Type encl = site.getEnclosingType();
2545                 while (encl != null && encl.hasTag(TYPEVAR))
2546                     encl = encl.getUpperBound();
2547                 if (encl.hasTag(CLASS)) {
2548                     // we are calling a nested class
2549 
2550                     if (tree.meth.hasTag(SELECT)) {
2551                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2552 
2553                         // We are seeing a prefixed call, of the form
2554                         //     <expr>.super(...).
2555                         // Check that the prefix expression conforms
2556                         // to the outer instance type of the class.
2557                         chk.checkRefType(qualifier.pos(),
2558                                          attribExpr(qualifier, localEnv,
2559                                                     encl));
2560                     } else if (methName == names._super) {
2561                         // qualifier omitted; check for existence
2562                         // of an appropriate implicit qualifier.
2563                         rs.resolveImplicitThis(tree.meth.pos(),
2564                                                localEnv, site, true);
2565                     }
2566                 } else if (tree.meth.hasTag(SELECT)) {
2567                     log.error(tree.meth.pos(),
2568                               Errors.IllegalQualNotIcls(site.tsym));
2569                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2570                 }
2571 
2572                 // if we're calling a java.lang.Enum constructor,
2573                 // prefix the implicit String and int parameters
2574                 if (site.tsym == syms.enumSym)
2575                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
2576 
2577                 // Resolve the called constructor under the assumption
2578                 // that we are referring to a superclass instance of the
2579                 // current instance (JLS ???).
2580                 boolean selectSuperPrev = localEnv.info.selectSuper;
2581                 localEnv.info.selectSuper = true;
2582                 localEnv.info.pendingResolutionPhase = null;
2583                 Symbol sym = rs.resolveConstructor(
2584                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
2585                 localEnv.info.selectSuper = selectSuperPrev;
2586 
2587                 // Set method symbol to resolved constructor...
2588                 TreeInfo.setSymbol(tree.meth, sym);
2589 
2590                 // ...and check that it is legal in the current context.
2591                 // (this will also set the tree's type)
2592                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2593                 checkId(tree.meth, site, sym, localEnv,
2594                         new ResultInfo(kind, mpt));
2595             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
2596                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2597             }
2598             // Otherwise, `site' is an error type and we do nothing
2599             result = tree.type = syms.voidType;
2600         } else {
2601             // Otherwise, we are seeing a regular method call.
2602             // Attribute the arguments, yielding list of argument types, ...
2603             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2604             argtypes = argtypesBuf.toList();
2605             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
2606 
2607             // ... and attribute the method using as a prototype a methodtype
2608             // whose formal argument types is exactly the list of actual
2609             // arguments (this will also set the method symbol).
2610             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2611             localEnv.info.pendingResolutionPhase = null;
2612             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
2613 
2614             // Compute the result type.
2615             Type restype = mtype.getReturnType();
2616             if (restype.hasTag(WILDCARD))
2617                 throw new AssertionError(mtype);
2618 
2619             Type qualifier = (tree.meth.hasTag(SELECT))
2620                     ? ((JCFieldAccess) tree.meth).selected.type
2621                     : env.enclClass.sym.type;
2622             Symbol msym = TreeInfo.symbol(tree.meth);
2623             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
2624 
2625             chk.checkRefTypes(tree.typeargs, typeargtypes);
2626 
2627             // Check that value of resulting type is admissible in the
2628             // current context.  Also, capture the return type
2629             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
2630             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
2631         }
2632         chk.validate(tree.typeargs, localEnv);
2633     }
2634     //where
2635         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
2636             if (msym != null &&
2637                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
2638                     methodName == names.getClass &&
2639                     argtypes.isEmpty()) {
2640                 // as a special case, x.getClass() has type Class<? extends |X|>
2641                 return new ClassType(restype.getEnclosingType(),
2642                         List.of(new WildcardType(types.erasure(qualifierType.baseType()),
2643                                 BoundKind.EXTENDS,
2644                                 syms.boundClass)),
2645                         restype.tsym,
2646                         restype.getMetadata());
2647             } else if (msym != null &&
2648                     msym.owner == syms.arrayClass &&
2649                     methodName == names.clone &&
2650                     types.isArray(qualifierType)) {
2651                 // as a special case, array.clone() has a result that is
2652                 // the same as static type of the array being cloned
2653                 return qualifierType;
2654             } else {
2655                 return restype;
2656             }
2657         }
2658 
2659         /** Obtain a method type with given argument types.
2660          */
2661         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
2662             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
2663             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
2664         }
2665 
2666     public void visitNewClass(final JCNewClass tree) {
2667         Type owntype = types.createErrorType(tree.type);
2668 
2669         // The local environment of a class creation is
2670         // a new environment nested in the current one.
2671         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2672 
2673         // The anonymous inner class definition of the new expression,
2674         // if one is defined by it.
2675         JCClassDecl cdef = tree.def;
2676 
2677         // If enclosing class is given, attribute it, and
2678         // complete class name to be fully qualified
2679         JCExpression clazz = tree.clazz; // Class field following new
2680         JCExpression clazzid;            // Identifier in class field
2681         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
2682         annoclazzid = null;
2683 
2684         if (clazz.hasTag(TYPEAPPLY)) {
2685             clazzid = ((JCTypeApply) clazz).clazz;
2686             if (clazzid.hasTag(ANNOTATED_TYPE)) {
2687                 annoclazzid = (JCAnnotatedType) clazzid;
2688                 clazzid = annoclazzid.underlyingType;
2689             }
2690         } else {
2691             if (clazz.hasTag(ANNOTATED_TYPE)) {
2692                 annoclazzid = (JCAnnotatedType) clazz;
2693                 clazzid = annoclazzid.underlyingType;
2694             } else {
2695                 clazzid = clazz;
2696             }
2697         }
2698 
2699         JCExpression clazzid1 = clazzid; // The same in fully qualified form
2700 
2701         if (tree.encl != null) {
2702             // We are seeing a qualified new, of the form
2703             //    <expr>.new C <...> (...) ...
2704             // In this case, we let clazz stand for the name of the
2705             // allocated class C prefixed with the type of the qualifier
2706             // expression, so that we can
2707             // resolve it with standard techniques later. I.e., if
2708             // <expr> has type T, then <expr>.new C <...> (...)
2709             // yields a clazz T.C.
2710             Type encltype = chk.checkRefType(tree.encl.pos(),
2711                                              attribExpr(tree.encl, env));
2712             // TODO 308: in <expr>.new C, do we also want to add the type annotations
2713             // from expr to the combined type, or not? Yes, do this.
2714             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
2715                                                  ((JCIdent) clazzid).name);
2716 
2717             EndPosTable endPosTable = this.env.toplevel.endPositions;
2718             endPosTable.storeEnd(clazzid1, clazzid.getEndPosition(endPosTable));
2719             if (clazz.hasTag(ANNOTATED_TYPE)) {
2720                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
2721                 List<JCAnnotation> annos = annoType.annotations;
2722 
2723                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
2724                     clazzid1 = make.at(tree.pos).
2725                         TypeApply(clazzid1,
2726                                   ((JCTypeApply) clazz).arguments);
2727                 }
2728 
2729                 clazzid1 = make.at(tree.pos).
2730                     AnnotatedType(annos, clazzid1);
2731             } else if (clazz.hasTag(TYPEAPPLY)) {
2732                 clazzid1 = make.at(tree.pos).
2733                     TypeApply(clazzid1,
2734                               ((JCTypeApply) clazz).arguments);
2735             }
2736 
2737             clazz = clazzid1;
2738         }
2739 
2740         // Attribute clazz expression and store
2741         // symbol + type back into the attributed tree.
2742         Type clazztype;
2743 
2744         try {
2745             env.info.isNewClass = true;
2746             clazztype = TreeInfo.isEnumInit(env.tree) ?
2747                 attribIdentAsEnumType(env, (JCIdent)clazz) :
2748                 attribType(clazz, env);
2749         } finally {
2750             env.info.isNewClass = false;
2751         }
2752 
2753         clazztype = chk.checkDiamond(tree, clazztype);
2754         chk.validate(clazz, localEnv);
2755         if (tree.encl != null) {
2756             // We have to work in this case to store
2757             // symbol + type back into the attributed tree.
2758             tree.clazz.type = clazztype;
2759             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
2760             clazzid.type = ((JCIdent) clazzid).sym.type;
2761             if (annoclazzid != null) {
2762                 annoclazzid.type = clazzid.type;
2763             }
2764             if (!clazztype.isErroneous()) {
2765                 if (cdef != null && clazztype.tsym.isInterface()) {
2766                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
2767                 } else if (clazztype.tsym.isStatic()) {
2768                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
2769                 }
2770             }
2771         } else if (!clazztype.tsym.isInterface() &&
2772                    clazztype.getEnclosingType().hasTag(CLASS)) {
2773             // Check for the existence of an apropos outer instance
2774             rs.resolveImplicitThis(tree.pos(), env, clazztype);
2775         }
2776 
2777         // Attribute constructor arguments.
2778         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2779         final KindSelector pkind =
2780             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2781         List<Type> argtypes = argtypesBuf.toList();
2782         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
2783 
2784         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
2785             // Enums may not be instantiated except implicitly
2786             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
2787                 (!env.tree.hasTag(VARDEF) ||
2788                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
2789                  ((JCVariableDecl) env.tree).init != tree))
2790                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
2791 
2792             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
2793                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
2794             boolean skipNonDiamondPath = false;
2795             // Check that class is not abstract
2796             if (cdef == null && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
2797                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
2798                 log.error(tree.pos(),
2799                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
2800                 skipNonDiamondPath = true;
2801             } else if (cdef != null && clazztype.tsym.isInterface()) {
2802                 // Check that no constructor arguments are given to
2803                 // anonymous classes implementing an interface
2804                 if (!argtypes.isEmpty())
2805                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
2806 
2807                 if (!typeargtypes.isEmpty())
2808                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
2809 
2810                 // Error recovery: pretend no arguments were supplied.
2811                 argtypes = List.nil();
2812                 typeargtypes = List.nil();
2813                 skipNonDiamondPath = true;
2814             }
2815             if (TreeInfo.isDiamond(tree)) {
2816                 ClassType site = new ClassType(clazztype.getEnclosingType(),
2817                             clazztype.tsym.type.getTypeArguments(),
2818                                                clazztype.tsym,
2819                                                clazztype.getMetadata());
2820 
2821                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
2822                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
2823                 diamondEnv.info.pendingResolutionPhase = null;
2824 
2825                 //if the type of the instance creation expression is a class type
2826                 //apply method resolution inference (JLS 15.12.2.7). The return type
2827                 //of the resolved constructor will be a partially instantiated type
2828                 Symbol constructor = rs.resolveDiamond(tree.pos(),
2829                             diamondEnv,
2830                             site,
2831                             argtypes,
2832                             typeargtypes);
2833                 tree.constructor = constructor.baseSymbol();
2834 
2835                 final TypeSymbol csym = clazztype.tsym;
2836                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
2837                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
2838                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
2839                 constructorType = checkId(tree, site,
2840                         constructor,
2841                         diamondEnv,
2842                         diamondResult);
2843 
2844                 tree.clazz.type = types.createErrorType(clazztype);
2845                 if (!constructorType.isErroneous()) {
2846                     tree.clazz.type = clazz.type = constructorType.getReturnType();
2847                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
2848                 }
2849                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
2850             }
2851 
2852             // Resolve the called constructor under the assumption
2853             // that we are referring to a superclass instance of the
2854             // current instance (JLS ???).
2855             else if (!skipNonDiamondPath) {
2856                 //the following code alters some of the fields in the current
2857                 //AttrContext - hence, the current context must be dup'ed in
2858                 //order to avoid downstream failures
2859                 Env<AttrContext> rsEnv = localEnv.dup(tree);
2860                 rsEnv.info.selectSuper = cdef != null;
2861                 rsEnv.info.pendingResolutionPhase = null;
2862                 tree.constructor = rs.resolveConstructor(
2863                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
2864                 if (cdef == null) { //do not check twice!
2865                     tree.constructorType = checkId(tree,
2866                             clazztype,
2867                             tree.constructor,
2868                             rsEnv,
2869                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
2870                     if (rsEnv.info.lastResolveVarargs())
2871                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
2872                 }
2873             }
2874 
2875             if (cdef != null) {
2876                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
2877                 return;
2878             }
2879 
2880             if (tree.constructor != null && tree.constructor.kind == MTH)
2881                 owntype = clazztype;
2882         }
2883         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2884         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2885         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
2886             //we need to wait for inference to finish and then replace inference vars in the constructor type
2887             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
2888                     instantiatedContext -> {
2889                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2890                     });
2891         }
2892         chk.validate(tree.typeargs, localEnv);
2893     }
2894 
2895         // where
2896         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
2897                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
2898                                                    List<Type> argtypes, List<Type> typeargtypes,
2899                                                    KindSelector pkind) {
2900             // We are seeing an anonymous class instance creation.
2901             // In this case, the class instance creation
2902             // expression
2903             //
2904             //    E.new <typeargs1>C<typargs2>(args) { ... }
2905             //
2906             // is represented internally as
2907             //
2908             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
2909             //
2910             // This expression is then *transformed* as follows:
2911             //
2912             // (1) add an extends or implements clause
2913             // (2) add a constructor.
2914             //
2915             // For instance, if C is a class, and ET is the type of E,
2916             // the expression
2917             //
2918             //    E.new <typeargs1>C<typargs2>(args) { ... }
2919             //
2920             // is translated to (where X is a fresh name and typarams is the
2921             // parameter list of the super constructor):
2922             //
2923             //   new <typeargs1>X(<*nullchk*>E, args) where
2924             //     X extends C<typargs2> {
2925             //       <typarams> X(ET e, args) {
2926             //         e.<typeargs1>super(args)
2927             //       }
2928             //       ...
2929             //     }
2930             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2931             Type enclType = clazztype.getEnclosingType();
2932             if (enclType != null &&
2933                     enclType.hasTag(CLASS) &&
2934                     !chk.checkDenotable((ClassType)enclType)) {
2935                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
2936             }
2937             final boolean isDiamond = TreeInfo.isDiamond(tree);
2938             if (isDiamond
2939                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
2940                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
2941                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
2942                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
2943                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
2944                         instantiatedContext -> {
2945                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2946                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
2947                             ResultInfo prevResult = this.resultInfo;
2948                             try {
2949                                 this.resultInfo = resultInfoForClassDefinition;
2950                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
2951                                         dupLocalEnv, argtypes, typeargtypes, pkind);
2952                             } finally {
2953                                 this.resultInfo = prevResult;
2954                             }
2955                         });
2956             } else {
2957                 if (isDiamond && clazztype.hasTag(CLASS)) {
2958                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
2959                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
2960                         // One or more types inferred in the previous steps is non-denotable.
2961                         Fragment fragment = Diamond(clazztype.tsym);
2962                         log.error(tree.clazz.pos(),
2963                                 Errors.CantApplyDiamond1(
2964                                         fragment,
2965                                         invalidDiamondArgs.size() > 1 ?
2966                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
2967                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
2968                     }
2969                     // For <>(){}, inferred types must also be accessible.
2970                     for (Type t : clazztype.getTypeArguments()) {
2971                         rs.checkAccessibleType(env, t);
2972                     }
2973                 }
2974 
2975                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
2976                 // false for isInterface call even when the original type is an interface.
2977                 boolean implementing = clazztype.tsym.isInterface() ||
2978                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
2979                         clazztype.getOriginalType().tsym.isInterface();
2980 
2981                 if (implementing) {
2982                     cdef.implementing = List.of(clazz);
2983                 } else {
2984                     cdef.extending = clazz;
2985                 }
2986 
2987                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
2988                     rs.isSerializable(clazztype)) {
2989                     localEnv.info.isSerializable = true;
2990                 }
2991 
2992                 attribStat(cdef, localEnv);
2993 
2994                 List<Type> finalargtypes;
2995                 // If an outer instance is given,
2996                 // prefix it to the constructor arguments
2997                 // and delete it from the new expression
2998                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
2999                     finalargtypes = argtypes.prepend(tree.encl.type);
3000                 } else {
3001                     finalargtypes = argtypes;
3002                 }
3003 
3004                 // Reassign clazztype and recompute constructor. As this necessarily involves
3005                 // another attribution pass for deferred types in the case of <>, replicate
3006                 // them. Original arguments have right decorations already.
3007                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3008                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3009                 }
3010 
3011                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3012                                                     : cdef.sym.type;
3013                 Symbol sym = tree.constructor = rs.resolveConstructor(
3014                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3015                 Assert.check(!sym.kind.isResolutionError());
3016                 tree.constructor = sym;
3017                 tree.constructorType = checkId(tree,
3018                         clazztype,
3019                         tree.constructor,
3020                         localEnv,
3021                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3022             }
3023             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3024                                 clazztype : types.createErrorType(tree.type);
3025             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3026             chk.validate(tree.typeargs, localEnv);
3027         }
3028 
3029         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3030             return new Check.NestedCheckContext(checkContext) {
3031                 @Override
3032                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3033                     enclosingContext.report(clazz.clazz,
3034                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3035                 }
3036             };
3037         }
3038 
3039     /** Make an attributed null check tree.
3040      */
3041     public JCExpression makeNullCheck(JCExpression arg) {
3042         // optimization: new Outer() can never be null; skip null check
3043         if (arg.getTag() == NEWCLASS)
3044             return arg;
3045         // optimization: X.this is never null; skip null check
3046         Name name = TreeInfo.name(arg);
3047         if (name == names._this || name == names._super) return arg;
3048 
3049         JCTree.Tag optag = NULLCHK;
3050         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3051         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3052         tree.type = arg.type;
3053         return tree;
3054     }
3055 
3056     public void visitNewArray(JCNewArray tree) {
3057         Type owntype = types.createErrorType(tree.type);
3058         Env<AttrContext> localEnv = env.dup(tree);
3059         Type elemtype;
3060         if (tree.elemtype != null) {
3061             elemtype = attribType(tree.elemtype, localEnv);
3062             chk.validate(tree.elemtype, localEnv);
3063             owntype = elemtype;
3064             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3065                 attribExpr(l.head, localEnv, syms.intType);
3066                 owntype = new ArrayType(owntype, syms.arrayClass);
3067             }
3068         } else {
3069             // we are seeing an untyped aggregate { ... }
3070             // this is allowed only if the prototype is an array
3071             if (pt().hasTag(ARRAY)) {
3072                 elemtype = types.elemtype(pt());
3073             } else {
3074                 if (!pt().hasTag(ERROR) &&
3075                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3076                     log.error(tree.pos(),
3077                               Errors.IllegalInitializerForType(pt()));
3078                 }
3079                 elemtype = types.createErrorType(pt());
3080             }
3081         }
3082         if (tree.elems != null) {
3083             attribExprs(tree.elems, localEnv, elemtype);
3084             owntype = new ArrayType(elemtype, syms.arrayClass);
3085         }
3086         if (!types.isReifiable(elemtype))
3087             log.error(tree.pos(), Errors.GenericArrayCreation);
3088         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3089     }
3090 
3091     /*
3092      * A lambda expression can only be attributed when a target-type is available.
3093      * In addition, if the target-type is that of a functional interface whose
3094      * descriptor contains inference variables in argument position the lambda expression
3095      * is 'stuck' (see DeferredAttr).
3096      */
3097     @Override
3098     public void visitLambda(final JCLambda that) {
3099         boolean wrongContext = false;
3100         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3101             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3102                 //lambda only allowed in assignment or method invocation/cast context
3103                 log.error(that.pos(), Errors.UnexpectedLambda);
3104             }
3105             resultInfo = recoveryInfo;
3106             wrongContext = true;
3107         }
3108         //create an environment for attribution of the lambda expression
3109         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3110         boolean needsRecovery =
3111                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3112         try {
3113             if (needsRecovery && rs.isSerializable(pt())) {
3114                 localEnv.info.isSerializable = true;
3115                 localEnv.info.isSerializableLambda = true;
3116             }
3117             List<Type> explicitParamTypes = null;
3118             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3119                 //attribute lambda parameters
3120                 attribStats(that.params, localEnv);
3121                 explicitParamTypes = TreeInfo.types(that.params);
3122             }
3123 
3124             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3125             Type currentTarget = targetInfo.target;
3126             Type lambdaType = targetInfo.descriptor;
3127 
3128             if (currentTarget.isErroneous()) {
3129                 result = that.type = currentTarget;
3130                 return;
3131             }
3132 
3133             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3134 
3135             if (lambdaType.hasTag(FORALL)) {
3136                 //lambda expression target desc cannot be a generic method
3137                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3138                                                                     kindName(currentTarget.tsym),
3139                                                                     currentTarget.tsym);
3140                 resultInfo.checkContext.report(that, diags.fragment(msg));
3141                 result = that.type = types.createErrorType(pt());
3142                 return;
3143             }
3144 
3145             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3146                 //add param type info in the AST
3147                 List<Type> actuals = lambdaType.getParameterTypes();
3148                 List<JCVariableDecl> params = that.params;
3149 
3150                 boolean arityMismatch = false;
3151 
3152                 while (params.nonEmpty()) {
3153                     if (actuals.isEmpty()) {
3154                         //not enough actuals to perform lambda parameter inference
3155                         arityMismatch = true;
3156                     }
3157                     //reset previously set info
3158                     Type argType = arityMismatch ?
3159                             syms.errType :
3160                             actuals.head;
3161                     if (params.head.isImplicitlyTyped()) {
3162                         setSyntheticVariableType(params.head, argType);
3163                     }
3164                     params.head.sym = null;
3165                     actuals = actuals.isEmpty() ?
3166                             actuals :
3167                             actuals.tail;
3168                     params = params.tail;
3169                 }
3170 
3171                 //attribute lambda parameters
3172                 attribStats(that.params, localEnv);
3173 
3174                 if (arityMismatch) {
3175                     resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3176                         result = that.type = types.createErrorType(currentTarget);
3177                         return;
3178                 }
3179             }
3180 
3181             //from this point on, no recovery is needed; if we are in assignment context
3182             //we will be able to attribute the whole lambda body, regardless of errors;
3183             //if we are in a 'check' method context, and the lambda is not compatible
3184             //with the target-type, it will be recovered anyway in Attr.checkId
3185             needsRecovery = false;
3186 
3187             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3188                     lambdaBodyResult(that, lambdaType, resultInfo);
3189 
3190             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3191                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3192             } else {
3193                 JCBlock body = (JCBlock)that.body;
3194                 if (body == breakTree &&
3195                         resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3196                     breakTreeFound(copyEnv(localEnv));
3197                 }
3198                 attribStats(body.stats, localEnv);
3199             }
3200 
3201             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3202 
3203             boolean isSpeculativeRound =
3204                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3205 
3206             preFlow(that);
3207             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3208 
3209             that.type = currentTarget; //avoids recovery at this stage
3210             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
3211 
3212             if (!isSpeculativeRound) {
3213                 //add thrown types as bounds to the thrown types free variables if needed:
3214                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3215                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3216                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3217                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3218                     }
3219                 }
3220 
3221                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3222             }
3223             result = wrongContext ? that.type = types.createErrorType(pt())
3224                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3225         } catch (Types.FunctionDescriptorLookupError ex) {
3226             JCDiagnostic cause = ex.getDiagnostic();
3227             resultInfo.checkContext.report(that, cause);
3228             result = that.type = types.createErrorType(pt());
3229             return;
3230         } catch (CompletionFailure cf) {
3231             chk.completionError(that.pos(), cf);
3232         } catch (Throwable t) {
3233             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3234             //as that would likely cause the same exception again.
3235             needsRecovery = false;
3236             throw t;
3237         } finally {
3238             localEnv.info.scope.leave();
3239             if (needsRecovery) {
3240                 Type prevResult = result;
3241                 try {
3242                     attribTree(that, env, recoveryInfo);
3243                 } finally {
3244                     if (result == Type.recoveryType) {
3245                         result = prevResult;
3246                     }
3247                 }
3248             }
3249         }
3250     }
3251     //where
3252         class TargetInfo {
3253             Type target;
3254             Type descriptor;
3255 
3256             public TargetInfo(Type target, Type descriptor) {
3257                 this.target = target;
3258                 this.descriptor = descriptor;
3259             }
3260         }
3261 
3262         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3263             Type lambdaType;
3264             Type currentTarget = resultInfo.pt;
3265             if (resultInfo.pt != Type.recoveryType) {
3266                 /* We need to adjust the target. If the target is an
3267                  * intersection type, for example: SAM & I1 & I2 ...
3268                  * the target will be updated to SAM
3269                  */
3270                 currentTarget = targetChecker.visit(currentTarget, that);
3271                 if (!currentTarget.isIntersection()) {
3272                     if (explicitParamTypes != null) {
3273                         currentTarget = infer.instantiateFunctionalInterface(that,
3274                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3275                     }
3276                     currentTarget = types.removeWildcards(currentTarget);
3277                     lambdaType = types.findDescriptorType(currentTarget);
3278                 } else {
3279                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3280                     ListBuffer<Type> components = new ListBuffer<>();
3281                     for (Type bound : ict.getExplicitComponents()) {
3282                         if (explicitParamTypes != null) {
3283                             try {
3284                                 bound = infer.instantiateFunctionalInterface(that,
3285                                         bound, explicitParamTypes, resultInfo.checkContext);
3286                             } catch (FunctionDescriptorLookupError t) {
3287                                 // do nothing
3288                             }
3289                         }
3290                         bound = types.removeWildcards(bound);
3291                         components.add(bound);
3292                     }
3293                     currentTarget = types.makeIntersectionType(components.toList());
3294                     currentTarget.tsym.flags_field |= INTERFACE;
3295                     lambdaType = types.findDescriptorType(currentTarget);
3296                 }
3297 
3298             } else {
3299                 currentTarget = Type.recoveryType;
3300                 lambdaType = fallbackDescriptorType(that);
3301             }
3302             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3303                 //lambda expression target desc cannot be a generic method
3304                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3305                                                                     kindName(currentTarget.tsym),
3306                                                                     currentTarget.tsym);
3307                 resultInfo.checkContext.report(that, diags.fragment(msg));
3308                 currentTarget = types.createErrorType(pt());
3309             }
3310             return new TargetInfo(currentTarget, lambdaType);
3311         }
3312 
3313         void preFlow(JCLambda tree) {
3314             attrRecover.doRecovery();
3315             new PostAttrAnalyzer() {
3316                 @Override
3317                 public void scan(JCTree tree) {
3318                     if (tree == null ||
3319                             (tree.type != null &&
3320                             tree.type == Type.stuckType)) {
3321                         //don't touch stuck expressions!
3322                         return;
3323                     }
3324                     super.scan(tree);
3325                 }
3326 
3327                 @Override
3328                 public void visitClassDef(JCClassDecl that) {
3329                     // or class declaration trees!
3330                 }
3331 
3332                 public void visitLambda(JCLambda that) {
3333                     // or lambda expressions!
3334                 }
3335             }.scan(tree.body);
3336         }
3337 
3338         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3339 
3340             @Override
3341             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3342                 return t.isIntersection() ?
3343                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3344             }
3345 
3346             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3347                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3348                 return ict;
3349             }
3350 
3351             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3352                 ListBuffer<Type> targs = new ListBuffer<>();
3353                 ListBuffer<Type> supertypes = new ListBuffer<>();
3354                 for (Type i : ict.interfaces_field) {
3355                     if (i.isParameterized()) {
3356                         targs.appendList(i.tsym.type.allparams());
3357                     }
3358                     supertypes.append(i.tsym.type);
3359                 }
3360                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3361                 notionalIntf.allparams_field = targs.toList();
3362                 notionalIntf.tsym.flags_field |= INTERFACE;
3363                 return notionalIntf.tsym;
3364             }
3365         };
3366 
3367         private Type fallbackDescriptorType(JCExpression tree) {
3368             switch (tree.getTag()) {
3369                 case LAMBDA:
3370                     JCLambda lambda = (JCLambda)tree;
3371                     List<Type> argtypes = List.nil();
3372                     for (JCVariableDecl param : lambda.params) {
3373                         argtypes = param.vartype != null && param.vartype.type != null ?
3374                                 argtypes.append(param.vartype.type) :
3375                                 argtypes.append(syms.errType);
3376                     }
3377                     return new MethodType(argtypes, Type.recoveryType,
3378                             List.of(syms.throwableType), syms.methodClass);
3379                 case REFERENCE:
3380                     return new MethodType(List.nil(), Type.recoveryType,
3381                             List.of(syms.throwableType), syms.methodClass);
3382                 default:
3383                     Assert.error("Cannot get here!");
3384             }
3385             return null;
3386         }
3387 
3388         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3389                 final InferenceContext inferenceContext, final Type... ts) {
3390             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3391         }
3392 
3393         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3394                 final InferenceContext inferenceContext, final List<Type> ts) {
3395             if (inferenceContext.free(ts)) {
3396                 inferenceContext.addFreeTypeListener(ts,
3397                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3398             } else {
3399                 for (Type t : ts) {
3400                     rs.checkAccessibleType(env, t);
3401                 }
3402             }
3403         }
3404 
3405         /**
3406          * Lambda/method reference have a special check context that ensures
3407          * that i.e. a lambda return type is compatible with the expected
3408          * type according to both the inherited context and the assignment
3409          * context.
3410          */
3411         class FunctionalReturnContext extends Check.NestedCheckContext {
3412 
3413             FunctionalReturnContext(CheckContext enclosingContext) {
3414                 super(enclosingContext);
3415             }
3416 
3417             @Override
3418             public boolean compatible(Type found, Type req, Warner warn) {
3419                 //return type must be compatible in both current context and assignment context
3420                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3421             }
3422 
3423             @Override
3424             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3425                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3426             }
3427         }
3428 
3429         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3430 
3431             JCExpression expr;
3432             boolean expStmtExpected;
3433 
3434             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3435                 super(enclosingContext);
3436                 this.expr = expr;
3437             }
3438 
3439             @Override
3440             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3441                 if (expStmtExpected) {
3442                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3443                 } else {
3444                     super.report(pos, details);
3445                 }
3446             }
3447 
3448             @Override
3449             public boolean compatible(Type found, Type req, Warner warn) {
3450                 //a void return is compatible with an expression statement lambda
3451                 if (req.hasTag(VOID)) {
3452                     expStmtExpected = true;
3453                     return TreeInfo.isExpressionStatement(expr);
3454                 } else {
3455                     return super.compatible(found, req, warn);
3456                 }
3457             }
3458         }
3459 
3460         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3461             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3462                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3463                     new FunctionalReturnContext(resultInfo.checkContext);
3464 
3465             return descriptor.getReturnType() == Type.recoveryType ?
3466                     recoveryInfo :
3467                     new ResultInfo(KindSelector.VAL,
3468                             descriptor.getReturnType(), funcContext);
3469         }
3470 
3471         /**
3472         * Lambda compatibility. Check that given return types, thrown types, parameter types
3473         * are compatible with the expected functional interface descriptor. This means that:
3474         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3475         * types must be compatible with the return type of the expected descriptor.
3476         */
3477         void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
3478             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3479 
3480             //return values have already been checked - but if lambda has no return
3481             //values, we must ensure that void/value compatibility is correct;
3482             //this amounts at checking that, if a lambda body can complete normally,
3483             //the descriptor's return type must be void
3484             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3485                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3486                 Fragment msg =
3487                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3488                 checkContext.report(tree,
3489                                     diags.fragment(msg));
3490             }
3491 
3492             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3493             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3494                 checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3495             }
3496         }
3497 
3498         /* Map to hold 'fake' clinit methods. If a lambda is used to initialize a
3499          * static field and that lambda has type annotations, these annotations will
3500          * also be stored at these fake clinit methods.
3501          *
3502          * LambdaToMethod also use fake clinit methods so they can be reused.
3503          * Also as LTM is a phase subsequent to attribution, the methods from
3504          * clinits can be safely removed by LTM to save memory.
3505          */
3506         private Map<ClassSymbol, MethodSymbol> clinits = new HashMap<>();
3507 
3508         public MethodSymbol removeClinit(ClassSymbol sym) {
3509             return clinits.remove(sym);
3510         }
3511 
3512         /* This method returns an environment to be used to attribute a lambda
3513          * expression.
3514          *
3515          * The owner of this environment is a method symbol. If the current owner
3516          * is not a method, for example if the lambda is used to initialize
3517          * a field, then if the field is:
3518          *
3519          * - an instance field, we use the first constructor.
3520          * - a static field, we create a fake clinit method.
3521          */
3522         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3523             Env<AttrContext> lambdaEnv;
3524             Symbol owner = env.info.scope.owner;
3525             if (owner.kind == VAR && owner.owner.kind == TYP) {
3526                 //field initializer
3527                 ClassSymbol enclClass = owner.enclClass();
3528                 Symbol newScopeOwner = env.info.scope.owner;
3529                 /* if the field isn't static, then we can get the first constructor
3530                  * and use it as the owner of the environment. This is what
3531                  * LTM code is doing to look for type annotations so we are fine.
3532                  */
3533                 if ((owner.flags() & STATIC) == 0) {
3534                     for (Symbol s : enclClass.members_field.getSymbolsByName(names.init)) {
3535                         newScopeOwner = s;
3536                         break;
3537                     }
3538                 } else {
3539                     /* if the field is static then we need to create a fake clinit
3540                      * method, this method can later be reused by LTM.
3541                      */
3542                     MethodSymbol clinit = clinits.get(enclClass);
3543                     if (clinit == null) {
3544                         Type clinitType = new MethodType(List.nil(),
3545                                 syms.voidType, List.nil(), syms.methodClass);
3546                         clinit = new MethodSymbol(STATIC | SYNTHETIC | PRIVATE,
3547                                 names.clinit, clinitType, enclClass);
3548                         clinit.params = List.nil();
3549                         clinits.put(enclClass, clinit);
3550                     }
3551                     newScopeOwner = clinit;
3552                 }
3553                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(newScopeOwner)));
3554             } else {
3555                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3556             }
3557             lambdaEnv.info.yieldResult = null;
3558             lambdaEnv.info.isLambda = true;
3559             return lambdaEnv;
3560         }
3561 
3562     @Override
3563     public void visitReference(final JCMemberReference that) {
3564         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3565             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3566                 //method reference only allowed in assignment or method invocation/cast context
3567                 log.error(that.pos(), Errors.UnexpectedMref);
3568             }
3569             result = that.type = types.createErrorType(pt());
3570             return;
3571         }
3572         final Env<AttrContext> localEnv = env.dup(that);
3573         try {
3574             //attribute member reference qualifier - if this is a constructor
3575             //reference, the expected kind must be a type
3576             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3577 
3578             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3579                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3580                 if (!exprType.isErroneous() &&
3581                     exprType.isRaw() &&
3582                     that.typeargs != null) {
3583                     log.error(that.expr.pos(),
3584                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3585                                                  Fragments.MrefInferAndExplicitParams));
3586                     exprType = types.createErrorType(exprType);
3587                 }
3588             }
3589 
3590             if (exprType.isErroneous()) {
3591                 //if the qualifier expression contains problems,
3592                 //give up attribution of method reference
3593                 result = that.type = exprType;
3594                 return;
3595             }
3596 
3597             if (TreeInfo.isStaticSelector(that.expr, names)) {
3598                 //if the qualifier is a type, validate it; raw warning check is
3599                 //omitted as we don't know at this stage as to whether this is a
3600                 //raw selector (because of inference)
3601                 chk.validate(that.expr, env, false);
3602             } else {
3603                 Symbol lhsSym = TreeInfo.symbol(that.expr);
3604                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
3605             }
3606             //attrib type-arguments
3607             List<Type> typeargtypes = List.nil();
3608             if (that.typeargs != null) {
3609                 typeargtypes = attribTypes(that.typeargs, localEnv);
3610             }
3611 
3612             boolean isTargetSerializable =
3613                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3614                     rs.isSerializable(pt());
3615             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
3616             Type currentTarget = targetInfo.target;
3617             Type desc = targetInfo.descriptor;
3618 
3619             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
3620             List<Type> argtypes = desc.getParameterTypes();
3621             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
3622 
3623             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
3624                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
3625             }
3626 
3627             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
3628             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
3629             try {
3630                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
3631                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
3632                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
3633             } finally {
3634                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
3635             }
3636 
3637             Symbol refSym = refResult.fst;
3638             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
3639 
3640             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
3641              *  JDK-8075541
3642              */
3643             if (refSym.kind != MTH) {
3644                 boolean targetError;
3645                 switch (refSym.kind) {
3646                     case ABSENT_MTH:
3647                     case MISSING_ENCL:
3648                         targetError = false;
3649                         break;
3650                     case WRONG_MTH:
3651                     case WRONG_MTHS:
3652                     case AMBIGUOUS:
3653                     case HIDDEN:
3654                     case STATICERR:
3655                         targetError = true;
3656                         break;
3657                     default:
3658                         Assert.error("unexpected result kind " + refSym.kind);
3659                         targetError = false;
3660                 }
3661 
3662                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
3663                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
3664                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
3665 
3666                 JCDiagnostic diag = diags.create(log.currentSource(), that,
3667                         targetError ?
3668                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
3669                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
3670 
3671                 if (targetError && currentTarget == Type.recoveryType) {
3672                     //a target error doesn't make sense during recovery stage
3673                     //as we don't know what actual parameter types are
3674                     result = that.type = currentTarget;
3675                     return;
3676                 } else {
3677                     if (targetError) {
3678                         resultInfo.checkContext.report(that, diag);
3679                     } else {
3680                         log.report(diag);
3681                     }
3682                     result = that.type = types.createErrorType(currentTarget);
3683                     return;
3684                 }
3685             }
3686 
3687             that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
3688             that.kind = lookupHelper.referenceKind(that.sym);
3689             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
3690 
3691             if (desc.getReturnType() == Type.recoveryType) {
3692                 // stop here
3693                 result = that.type = currentTarget;
3694                 return;
3695             }
3696 
3697             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3698                 Type enclosingType = exprType.getEnclosingType();
3699                 if (enclosingType != null && enclosingType.hasTag(CLASS)) {
3700                     // Check for the existence of an appropriate outer instance
3701                     rs.resolveImplicitThis(that.pos(), env, exprType);
3702                 }
3703             }
3704 
3705             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3706 
3707                 if (that.getMode() == ReferenceMode.INVOKE &&
3708                         TreeInfo.isStaticSelector(that.expr, names) &&
3709                         that.kind.isUnbound() &&
3710                         lookupHelper.site.isRaw()) {
3711                     chk.checkRaw(that.expr, localEnv);
3712                 }
3713 
3714                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
3715                         exprType.getTypeArguments().nonEmpty()) {
3716                     //static ref with class type-args
3717                     log.error(that.expr.pos(),
3718                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3719                                                  Fragments.StaticMrefWithTargs));
3720                     result = that.type = types.createErrorType(currentTarget);
3721                     return;
3722                 }
3723 
3724                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
3725                     // Check that super-qualified symbols are not abstract (JLS)
3726                     rs.checkNonAbstract(that.pos(), that.sym);
3727                 }
3728 
3729                 if (isTargetSerializable) {
3730                     chk.checkAccessFromSerializableElement(that, true);
3731                 }
3732             }
3733 
3734             ResultInfo checkInfo =
3735                     resultInfo.dup(newMethodTemplate(
3736                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
3737                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
3738                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3739 
3740             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
3741 
3742             if (that.kind.isUnbound() &&
3743                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
3744                 //re-generate inference constraints for unbound receiver
3745                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
3746                     //cannot happen as this has already been checked - we just need
3747                     //to regenerate the inference constraints, as that has been lost
3748                     //as a result of the call to inferenceContext.save()
3749                     Assert.error("Can't get here");
3750                 }
3751             }
3752 
3753             if (!refType.isErroneous()) {
3754                 refType = types.createMethodTypeWithReturn(refType,
3755                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
3756             }
3757 
3758             //go ahead with standard method reference compatibility check - note that param check
3759             //is a no-op (as this has been taken care during method applicability)
3760             boolean isSpeculativeRound =
3761                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3762 
3763             that.type = currentTarget; //avoids recovery at this stage
3764             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
3765             if (!isSpeculativeRound) {
3766                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
3767             }
3768             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3769         } catch (Types.FunctionDescriptorLookupError ex) {
3770             JCDiagnostic cause = ex.getDiagnostic();
3771             resultInfo.checkContext.report(that, cause);
3772             result = that.type = types.createErrorType(pt());
3773             return;
3774         }
3775     }
3776     //where
3777         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
3778             //if this is a constructor reference, the expected kind must be a type
3779             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
3780                                   KindSelector.VAL_TYP : KindSelector.TYP,
3781                                   Type.noType);
3782         }
3783 
3784 
3785     @SuppressWarnings("fallthrough")
3786     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
3787         InferenceContext inferenceContext = checkContext.inferenceContext();
3788         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
3789 
3790         Type resType;
3791         switch (tree.getMode()) {
3792             case NEW:
3793                 if (!tree.expr.type.isRaw()) {
3794                     resType = tree.expr.type;
3795                     break;
3796                 }
3797             default:
3798                 resType = refType.getReturnType();
3799         }
3800 
3801         Type incompatibleReturnType = resType;
3802 
3803         if (returnType.hasTag(VOID)) {
3804             incompatibleReturnType = null;
3805         }
3806 
3807         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
3808             if (resType.isErroneous() ||
3809                     new FunctionalReturnContext(checkContext).compatible(resType, returnType,
3810                             checkContext.checkWarner(tree, resType, returnType))) {
3811                 incompatibleReturnType = null;
3812             }
3813         }
3814 
3815         if (incompatibleReturnType != null) {
3816             Fragment msg =
3817                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
3818             checkContext.report(tree, diags.fragment(msg));
3819         } else {
3820             if (inferenceContext.free(refType)) {
3821                 // we need to wait for inference to finish and then replace inference vars in the referent type
3822                 inferenceContext.addFreeTypeListener(List.of(refType),
3823                         instantiatedContext -> {
3824                             tree.referentType = instantiatedContext.asInstType(refType);
3825                         });
3826             } else {
3827                 tree.referentType = refType;
3828             }
3829         }
3830 
3831         if (!speculativeAttr) {
3832             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
3833                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
3834             }
3835         }
3836     }
3837 
3838     boolean checkExConstraints(
3839             List<Type> thrownByFuncExpr,
3840             List<Type> thrownAtFuncType,
3841             InferenceContext inferenceContext) {
3842         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
3843          *  are not proper types
3844          */
3845         List<Type> nonProperList = thrownAtFuncType.stream()
3846                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
3847         List<Type> properList = thrownAtFuncType.diff(nonProperList);
3848 
3849         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
3850          *  in the throws clause of the invocation type of the method reference's compile-time
3851          *  declaration
3852          */
3853         List<Type> checkedList = thrownByFuncExpr.stream()
3854                 .filter(e -> chk.isChecked(e)).collect(List.collector());
3855 
3856         /** If n = 0 (the function type's throws clause consists only of proper types), then
3857          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
3858          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
3859          *  reduces to true
3860          */
3861         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
3862         for (Type checked : checkedList) {
3863             boolean isSubtype = false;
3864             for (Type proper : properList) {
3865                 if (types.isSubtype(checked, proper)) {
3866                     isSubtype = true;
3867                     break;
3868                 }
3869             }
3870             if (!isSubtype) {
3871                 uncaughtByProperTypes.add(checked);
3872             }
3873         }
3874 
3875         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
3876             return false;
3877         }
3878 
3879         /** If n > 0, the constraint reduces to a set of subtyping constraints:
3880          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
3881          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
3882          */
3883         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
3884         uncaughtByProperTypes.forEach(checkedEx -> {
3885             nonProperAsUndet.forEach(nonProper -> {
3886                 types.isSubtype(checkedEx, nonProper);
3887             });
3888         });
3889 
3890         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
3891          */
3892         nonProperAsUndet.stream()
3893                 .filter(t -> t.hasTag(UNDETVAR))
3894                 .forEach(t -> ((UndetVar)t).setThrow());
3895         return true;
3896     }
3897 
3898     /**
3899      * Set functional type info on the underlying AST. Note: as the target descriptor
3900      * might contain inference variables, we might need to register an hook in the
3901      * current inference context.
3902      */
3903     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
3904             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
3905         if (checkContext.inferenceContext().free(descriptorType)) {
3906             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
3907                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
3908                     inferenceContext.asInstType(primaryTarget), checkContext));
3909         } else {
3910             if (pt.hasTag(CLASS)) {
3911                 fExpr.target = primaryTarget;
3912             }
3913             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3914                     pt != Type.recoveryType) {
3915                 //check that functional interface class is well-formed
3916                 try {
3917                     /* Types.makeFunctionalInterfaceClass() may throw an exception
3918                      * when it's executed post-inference. See the listener code
3919                      * above.
3920                      */
3921                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
3922                             names.empty, fExpr.target, ABSTRACT);
3923                     if (csym != null) {
3924                         chk.checkImplementations(env.tree, csym, csym);
3925                         try {
3926                             //perform an additional functional interface check on the synthetic class,
3927                             //as there may be spurious errors for raw targets - because of existing issues
3928                             //with membership and inheritance (see JDK-8074570).
3929                             csym.flags_field |= INTERFACE;
3930                             types.findDescriptorType(csym.type);
3931                         } catch (FunctionDescriptorLookupError err) {
3932                             resultInfo.checkContext.report(fExpr,
3933                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
3934                         }
3935                     }
3936                 } catch (Types.FunctionDescriptorLookupError ex) {
3937                     JCDiagnostic cause = ex.getDiagnostic();
3938                     resultInfo.checkContext.report(env.tree, cause);
3939                 }
3940             }
3941         }
3942     }
3943 
3944     public void visitParens(JCParens tree) {
3945         Type owntype = attribTree(tree.expr, env, resultInfo);
3946         result = check(tree, owntype, pkind(), resultInfo);
3947         Symbol sym = TreeInfo.symbol(tree);
3948         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
3949             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
3950     }
3951 
3952     public void visitAssign(JCAssign tree) {
3953         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
3954         Type capturedType = capture(owntype);
3955         attribExpr(tree.rhs, env, owntype);
3956         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
3957     }
3958 
3959     public void visitAssignop(JCAssignOp tree) {
3960         // Attribute arguments.
3961         Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
3962         Type operand = attribExpr(tree.rhs, env);
3963         // Find operator.
3964         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
3965         if (operator != operators.noOpSymbol &&
3966                 !owntype.isErroneous() &&
3967                 !operand.isErroneous()) {
3968             chk.checkDivZero(tree.rhs.pos(), operator, operand);
3969             chk.checkCastable(tree.rhs.pos(),
3970                               operator.type.getReturnType(),
3971                               owntype);
3972             chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
3973         }
3974         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3975     }
3976 
3977     public void visitUnary(JCUnary tree) {
3978         // Attribute arguments.
3979         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
3980             ? attribTree(tree.arg, env, varAssignmentInfo)
3981             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
3982 
3983         // Find operator.
3984         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
3985         Type owntype = types.createErrorType(tree.type);
3986         if (operator != operators.noOpSymbol &&
3987                 !argtype.isErroneous()) {
3988             owntype = (tree.getTag().isIncOrDecUnaryOp())
3989                 ? tree.arg.type
3990                 : operator.type.getReturnType();
3991             int opc = operator.opcode;
3992 
3993             // If the argument is constant, fold it.
3994             if (argtype.constValue() != null) {
3995                 Type ctype = cfolder.fold1(opc, argtype);
3996                 if (ctype != null) {
3997                     owntype = cfolder.coerce(ctype, owntype);
3998                 }
3999             }
4000         }
4001         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4002         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4003     }
4004 
4005     public void visitBinary(JCBinary tree) {
4006         // Attribute arguments.
4007         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4008         // x && y
4009         // include x's bindings when true in y
4010 
4011         // x || y
4012         // include x's bindings when false in y
4013 
4014         MatchBindings lhsBindings = matchBindings;
4015         List<BindingSymbol> propagatedBindings;
4016         switch (tree.getTag()) {
4017             case AND:
4018                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4019                 break;
4020             case OR:
4021                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4022                 break;
4023             default:
4024                 propagatedBindings = List.nil();
4025                 break;
4026         }
4027         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4028         Type right;
4029         try {
4030             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4031         } finally {
4032             rhsEnv.info.scope.leave();
4033         }
4034 
4035         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4036 
4037         // Find operator.
4038         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4039         Type owntype = types.createErrorType(tree.type);
4040         if (operator != operators.noOpSymbol &&
4041                 !left.isErroneous() &&
4042                 !right.isErroneous()) {
4043             owntype = operator.type.getReturnType();
4044             int opc = operator.opcode;
4045             // If both arguments are constants, fold them.
4046             if (left.constValue() != null && right.constValue() != null) {
4047                 Type ctype = cfolder.fold2(opc, left, right);
4048                 if (ctype != null) {
4049                     owntype = cfolder.coerce(ctype, owntype);
4050                 }
4051             }
4052 
4053             // Check that argument types of a reference ==, != are
4054             // castable to each other, (JLS 15.21).  Note: unboxing
4055             // comparisons will not have an acmp* opc at this point.
4056             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4057                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4058                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4059                 }
4060             }
4061 
4062             chk.checkDivZero(tree.rhs.pos(), operator, right);
4063         }
4064         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4065     }
4066 
4067     public void visitTypeCast(final JCTypeCast tree) {
4068         Type clazztype = attribType(tree.clazz, env);
4069         chk.validate(tree.clazz, env, false);
4070         //a fresh environment is required for 292 inference to work properly ---
4071         //see Infer.instantiatePolymorphicSignatureInstance()
4072         Env<AttrContext> localEnv = env.dup(tree);
4073         //should we propagate the target type?
4074         final ResultInfo castInfo;
4075         JCExpression expr = TreeInfo.skipParens(tree.expr);
4076         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4077         if (isPoly) {
4078             //expression is a poly - we need to propagate target type info
4079             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4080                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4081                 @Override
4082                 public boolean compatible(Type found, Type req, Warner warn) {
4083                     return types.isCastable(found, req, warn);
4084                 }
4085             });
4086         } else {
4087             //standalone cast - target-type info is not propagated
4088             castInfo = unknownExprInfo;
4089         }
4090         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4091         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4092         if (exprtype.constValue() != null)
4093             owntype = cfolder.coerce(exprtype, owntype);
4094         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4095         if (!isPoly)
4096             chk.checkRedundantCast(localEnv, tree);
4097     }
4098 
4099     public void visitTypeTest(JCInstanceOf tree) {
4100         Type exprtype = chk.checkNullOrRefType(
4101                 tree.expr.pos(), attribExpr(tree.expr, env));
4102         Type clazztype;
4103         JCTree typeTree;
4104         if (tree.pattern.getTag() == BINDINGPATTERN ||
4105             tree.pattern.getTag() == RECORDPATTERN) {
4106             attribExpr(tree.pattern, env, exprtype);
4107             clazztype = tree.pattern.type;
4108             if (types.isSubtype(exprtype, clazztype) &&
4109                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4110                 tree.pattern.getTag() != RECORDPATTERN) {
4111                 if (!allowUnconditionalPatternsInstanceOf) {
4112                     log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(),
4113                               Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.error(this.sourceName));
4114                 }
4115             }
4116             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4117         } else {
4118             clazztype = attribType(tree.pattern, env);
4119             typeTree = tree.pattern;
4120             chk.validate(typeTree, env, false);
4121         }
4122         if (!clazztype.hasTag(TYPEVAR)) {
4123             clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4124         }
4125         if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4126             boolean valid = false;
4127             if (allowReifiableTypesInInstanceof) {
4128                 valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4129             } else {
4130                 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(),
4131                           Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4132                 allowReifiableTypesInInstanceof = true;
4133             }
4134             if (!valid) {
4135                 clazztype = types.createErrorType(clazztype);
4136             }
4137         }
4138         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4139         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4140     }
4141 
4142     private boolean checkCastablePattern(DiagnosticPosition pos,
4143                                          Type exprType,
4144                                          Type pattType) {
4145         Warner warner = new Warner();
4146         // if any type is erroneous, the problem is reported elsewhere
4147         if (exprType.isErroneous() || pattType.isErroneous()) {
4148             return false;
4149         }
4150         if (!types.isCastable(exprType, pattType, warner)) {
4151             chk.basicHandler.report(pos,
4152                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4153             return false;
4154         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4155                    (!exprType.isPrimitive() ||
4156                     !pattType.isPrimitive() ||
4157                     !types.isSameType(exprType, pattType))) {
4158             chk.basicHandler.report(pos,
4159                     diags.fragment(Fragments.NotApplicableTypes(exprType, pattType)));
4160             return false;
4161         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4162             log.error(pos,
4163                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4164             return false;
4165         } else {
4166             return true;
4167         }
4168     }
4169 
4170     @Override
4171     public void visitAnyPattern(JCAnyPattern tree) {
4172         result = tree.type = resultInfo.pt;
4173     }
4174 
4175     public void visitBindingPattern(JCBindingPattern tree) {
4176         Type type;
4177         if (tree.var.vartype != null) {
4178             type = attribType(tree.var.vartype, env);
4179         } else {
4180             type = resultInfo.pt;
4181         }
4182         tree.type = tree.var.type = type;
4183         BindingSymbol v = new BindingSymbol(tree.var.mods.flags, tree.var.name, type, env.info.scope.owner);
4184         v.pos = tree.pos;
4185         tree.var.sym = v;
4186         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4187             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4188         }
4189         annotate.annotateLater(tree.var.mods.annotations, env, v, tree.pos());
4190         if (!tree.var.isImplicitlyTyped()) {
4191             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v, tree.var.pos());
4192         }
4193         annotate.flush();
4194         chk.validate(tree.var.vartype, env, true);
4195         result = tree.type;
4196         if (v.isUnnamedVariable()) {
4197             matchBindings = MatchBindingsComputer.EMPTY;
4198         } else {
4199             matchBindings = new MatchBindings(List.of(v), List.nil());
4200         }
4201     }
4202 
4203     @Override
4204     public void visitRecordPattern(JCRecordPattern tree) {
4205         Type site;
4206 
4207         if (tree.deconstructor == null) {
4208             log.error(tree.pos(), Errors.DeconstructionPatternVarNotAllowed);
4209             tree.record = syms.errSymbol;
4210             site = tree.type = types.createErrorType(tree.record.type);
4211         } else {
4212             Type type = attribType(tree.deconstructor, env);
4213             if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4214                 Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4215                 if (inferred == null) {
4216                     log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4217                 } else {
4218                     type = inferred;
4219                 }
4220             }
4221             tree.type = tree.deconstructor.type = type;
4222             site = types.capture(tree.type);
4223         }
4224 
4225         List<Type> expectedRecordTypes;
4226         if (site.tsym.kind == Kind.TYP && ((ClassSymbol) site.tsym).isRecord()) {
4227             ClassSymbol record = (ClassSymbol) site.tsym;
4228             expectedRecordTypes = record.getRecordComponents()
4229                                         .stream()
4230                                         .map(rc -> types.memberType(site, rc))
4231                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4232                                         .collect(List.collector());
4233             tree.record = record;
4234         } else {
4235             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4236             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4237                                 .limit(tree.nested.size())
4238                                 .collect(List.collector());
4239             tree.record = syms.errSymbol;
4240         }
4241         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4242         List<Type> recordTypes = expectedRecordTypes;
4243         List<JCPattern> nestedPatterns = tree.nested;
4244         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4245         try {
4246             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4247                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4248                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4249                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4250                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4251                 nestedPatterns = nestedPatterns.tail;
4252                 recordTypes = recordTypes.tail;
4253             }
4254             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4255                 while (nestedPatterns.nonEmpty()) {
4256                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4257                     nestedPatterns = nestedPatterns.tail;
4258                 }
4259                 List<Type> nestedTypes =
4260                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4261                 log.error(tree.pos(),
4262                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4263                                                                  nestedTypes));
4264             }
4265         } finally {
4266             localEnv.info.scope.leave();
4267         }
4268         chk.validate(tree.deconstructor, env, true);
4269         result = tree.type;
4270         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4271     }
4272 
4273     public void visitIndexed(JCArrayAccess tree) {
4274         Type owntype = types.createErrorType(tree.type);
4275         Type atype = attribExpr(tree.indexed, env);
4276         attribExpr(tree.index, env, syms.intType);
4277         if (types.isArray(atype))
4278             owntype = types.elemtype(atype);
4279         else if (!atype.hasTag(ERROR))
4280             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4281         if (!pkind().contains(KindSelector.VAL))
4282             owntype = capture(owntype);
4283         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4284     }
4285 
4286     public void visitIdent(JCIdent tree) {
4287         Symbol sym;
4288 
4289         // Find symbol
4290         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4291             // If we are looking for a method, the prototype `pt' will be a
4292             // method type with the type of the call's arguments as parameters.
4293             env.info.pendingResolutionPhase = null;
4294             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4295         } else if (tree.sym != null && tree.sym.kind != VAR) {
4296             sym = tree.sym;
4297         } else {
4298             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4299         }
4300         tree.sym = sym;
4301 
4302         // Also find the environment current for the class where
4303         // sym is defined (`symEnv').
4304         Env<AttrContext> symEnv = env;
4305         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4306             sym.kind.matches(KindSelector.VAL_MTH) &&
4307             sym.owner.kind == TYP &&
4308             tree.name != names._this && tree.name != names._super) {
4309 
4310             // Find environment in which identifier is defined.
4311             while (symEnv.outer != null &&
4312                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4313                 symEnv = symEnv.outer;
4314             }
4315         }
4316 
4317         // If symbol is a variable, ...
4318         if (sym.kind == VAR) {
4319             VarSymbol v = (VarSymbol)sym;
4320 
4321             // ..., evaluate its initializer, if it has one, and check for
4322             // illegal forward reference.
4323             checkInit(tree, env, v, false);
4324 
4325             // If we are expecting a variable (as opposed to a value), check
4326             // that the variable is assignable in the current environment.
4327             if (KindSelector.ASG.subset(pkind()))
4328                 checkAssignable(tree.pos(), v, null, env);
4329         }
4330 
4331         Env<AttrContext> env1 = env;
4332         if (sym.kind != ERR && sym.kind != TYP &&
4333             sym.owner != null && sym.owner != env1.enclClass.sym) {
4334             // If the found symbol is inaccessible, then it is
4335             // accessed through an enclosing instance.  Locate this
4336             // enclosing instance:
4337             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4338                 env1 = env1.outer;
4339         }
4340 
4341         if (env.info.isSerializable) {
4342             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4343         }
4344 
4345         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4346     }
4347 
4348     public void visitSelect(JCFieldAccess tree) {
4349         // Determine the expected kind of the qualifier expression.
4350         KindSelector skind = KindSelector.NIL;
4351         if (tree.name == names._this || tree.name == names._super ||
4352                 tree.name == names._class)
4353         {
4354             skind = KindSelector.TYP;
4355         } else {
4356             if (pkind().contains(KindSelector.PCK))
4357                 skind = KindSelector.of(skind, KindSelector.PCK);
4358             if (pkind().contains(KindSelector.TYP))
4359                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4360             if (pkind().contains(KindSelector.VAL_MTH))
4361                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4362         }
4363 
4364         // Attribute the qualifier expression, and determine its symbol (if any).
4365         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));

4366         if (!pkind().contains(KindSelector.TYP_PCK))
4367             site = capture(site); // Capture field access
4368 
4369         // don't allow T.class T[].class, etc
4370         if (skind == KindSelector.TYP) {
4371             Type elt = site;
4372             while (elt.hasTag(ARRAY))
4373                 elt = ((ArrayType)elt).elemtype;
4374             if (elt.hasTag(TYPEVAR)) {
4375                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4376                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4377                 tree.sym = tree.type.tsym;
4378                 return ;
4379             }
4380         }
4381 
4382         // If qualifier symbol is a type or `super', assert `selectSuper'
4383         // for the selection. This is relevant for determining whether
4384         // protected symbols are accessible.
4385         Symbol sitesym = TreeInfo.symbol(tree.selected);
4386         boolean selectSuperPrev = env.info.selectSuper;
4387         env.info.selectSuper =
4388             sitesym != null &&
4389             sitesym.name == names._super;
4390 
4391         // Determine the symbol represented by the selection.
4392         env.info.pendingResolutionPhase = null;
4393         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
4394         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4395             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4396             sym = syms.errSymbol;
4397         }
4398         if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
4399             site = capture(site);
4400             sym = selectSym(tree, sitesym, site, env, resultInfo);
4401         }
4402         boolean varArgs = env.info.lastResolveVarargs();
4403         tree.sym = sym;
4404 
4405         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4406             site = types.skipTypeVars(site, true);
4407         }
4408 
4409         // If that symbol is a variable, ...
4410         if (sym.kind == VAR) {
4411             VarSymbol v = (VarSymbol)sym;
4412 
4413             // ..., evaluate its initializer, if it has one, and check for
4414             // illegal forward reference.
4415             checkInit(tree, env, v, true);
4416 
4417             // If we are expecting a variable (as opposed to a value), check
4418             // that the variable is assignable in the current environment.
4419             if (KindSelector.ASG.subset(pkind()))
4420                 checkAssignable(tree.pos(), v, tree.selected, env);
4421         }
4422 
4423         if (sitesym != null &&
4424                 sitesym.kind == VAR &&
4425                 ((VarSymbol)sitesym).isResourceVariable() &&
4426                 sym.kind == MTH &&
4427                 sym.name.equals(names.close) &&
4428                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
4429                 env.info.lint.isEnabled(LintCategory.TRY)) {
4430             log.warning(LintCategory.TRY, tree, Warnings.TryExplicitCloseCall);
4431         }
4432 
4433         // Disallow selecting a type from an expression
4434         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4435             tree.type = check(tree.selected, pt(),
4436                               sitesym == null ?
4437                                       KindSelector.VAL : sitesym.kind.toSelector(),
4438                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4439         }
4440 
4441         if (isType(sitesym)) {
4442             if (sym.name != names._this && sym.name != names._super) {
4443                 // Check if type-qualified fields or methods are static (JLS)
4444                 if ((sym.flags() & STATIC) == 0 &&
4445                     sym.name != names._super &&
4446                     (sym.kind == VAR || sym.kind == MTH)) {
4447                     rs.accessBase(rs.new StaticError(sym),
4448                               tree.pos(), site, sym.name, true);
4449                 }
4450             }
4451         } else if (sym.kind != ERR &&
4452                    (sym.flags() & STATIC) != 0 &&
4453                    sym.name != names._class) {
4454             // If the qualified item is not a type and the selected item is static, report
4455             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4456             if (!sym.owner.isAnonymous()) {
4457                 chk.warnStatic(tree, Warnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4458             } else {
4459                 chk.warnStatic(tree, Warnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4460             }
4461         }
4462 
4463         // If we are selecting an instance member via a `super', ...
4464         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4465 
4466             // Check that super-qualified symbols are not abstract (JLS)
4467             rs.checkNonAbstract(tree.pos(), sym);
4468 
4469             if (site.isRaw()) {
4470                 // Determine argument types for site.
4471                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
4472                 if (site1 != null) site = site1;
4473             }
4474         }
4475 
4476         if (env.info.isSerializable) {
4477             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4478         }
4479 
4480         env.info.selectSuper = selectSuperPrev;
4481         result = checkId(tree, site, sym, env, resultInfo);
4482     }
4483     //where
4484         /** Determine symbol referenced by a Select expression,
4485          *
4486          *  @param tree   The select tree.
4487          *  @param site   The type of the selected expression,
4488          *  @param env    The current environment.
4489          *  @param resultInfo The current result.
4490          */
4491         private Symbol selectSym(JCFieldAccess tree,
4492                                  Symbol location,
4493                                  Type site,
4494                                  Env<AttrContext> env,
4495                                  ResultInfo resultInfo) {
4496             DiagnosticPosition pos = tree.pos();
4497             Name name = tree.name;
4498             switch (site.getTag()) {
4499             case PACKAGE:
4500                 return rs.accessBase(
4501                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4502                     pos, location, site, name, true);
4503             case ARRAY:
4504             case CLASS:
4505                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4506                     return rs.resolveQualifiedMethod(
4507                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4508                 } else if (name == names._this || name == names._super) {
4509                     return rs.resolveSelf(pos, env, site.tsym, name);
4510                 } else if (name == names._class) {
4511                     // In this case, we have already made sure in
4512                     // visitSelect that qualifier expression is a type.
4513                     return syms.getClassField(site, types);
4514                 } else {
4515                     // We are seeing a plain identifier as selector.
4516                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
4517                         sym = rs.accessBase(sym, pos, location, site, name, true);
4518                     return sym;
4519                 }
4520             case WILDCARD:
4521                 throw new AssertionError(tree);
4522             case TYPEVAR:
4523                 // Normally, site.getUpperBound() shouldn't be null.
4524                 // It should only happen during memberEnter/attribBase
4525                 // when determining the supertype which *must* be
4526                 // done before attributing the type variables.  In
4527                 // other words, we are seeing this illegal program:
4528                 // class B<T> extends A<T.foo> {}
4529                 Symbol sym = (site.getUpperBound() != null)
4530                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
4531                     : null;
4532                 if (sym == null) {
4533                     log.error(pos, Errors.TypeVarCantBeDeref);
4534                     return syms.errSymbol;
4535                 } else {
4536                     Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
4537                         rs.new AccessError(env, site, sym) :
4538                                 sym;
4539                     rs.accessBase(sym2, pos, location, site, name, true);
4540                     return sym;
4541                 }
4542             case ERROR:
4543                 // preserve identifier names through errors
4544                 return types.createErrorType(name, site.tsym, site).tsym;
4545             default:
4546                 // The qualifier expression is of a primitive type -- only
4547                 // .class is allowed for these.
4548                 if (name == names._class) {
4549                     // In this case, we have already made sure in Select that
4550                     // qualifier expression is a type.
4551                     return syms.getClassField(site, types);
4552                 } else {
4553                     log.error(pos, Errors.CantDeref(site));
4554                     return syms.errSymbol;
4555                 }
4556             }
4557         }
4558 
4559         /** Determine type of identifier or select expression and check that
4560          *  (1) the referenced symbol is not deprecated
4561          *  (2) the symbol's type is safe (@see checkSafe)
4562          *  (3) if symbol is a variable, check that its type and kind are
4563          *      compatible with the prototype and protokind.
4564          *  (4) if symbol is an instance field of a raw type,
4565          *      which is being assigned to, issue an unchecked warning if its
4566          *      type changes under erasure.
4567          *  (5) if symbol is an instance method of a raw type, issue an
4568          *      unchecked warning if its argument types change under erasure.
4569          *  If checks succeed:
4570          *    If symbol is a constant, return its constant type
4571          *    else if symbol is a method, return its result type
4572          *    otherwise return its type.
4573          *  Otherwise return errType.
4574          *
4575          *  @param tree       The syntax tree representing the identifier
4576          *  @param site       If this is a select, the type of the selected
4577          *                    expression, otherwise the type of the current class.
4578          *  @param sym        The symbol representing the identifier.
4579          *  @param env        The current environment.
4580          *  @param resultInfo    The expected result
4581          */
4582         Type checkId(JCTree tree,
4583                      Type site,
4584                      Symbol sym,
4585                      Env<AttrContext> env,
4586                      ResultInfo resultInfo) {
4587             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
4588                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
4589                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4590         }
4591 
4592         Type checkMethodIdInternal(JCTree tree,
4593                      Type site,
4594                      Symbol sym,
4595                      Env<AttrContext> env,
4596                      ResultInfo resultInfo) {
4597             if (resultInfo.pkind.contains(KindSelector.POLY)) {
4598                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
4599             } else {
4600                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4601             }
4602         }
4603 
4604         Type checkIdInternal(JCTree tree,
4605                      Type site,
4606                      Symbol sym,
4607                      Type pt,
4608                      Env<AttrContext> env,
4609                      ResultInfo resultInfo) {
4610             if (pt.isErroneous()) {
4611                 return types.createErrorType(site);
4612             }
4613             Type owntype; // The computed type of this identifier occurrence.
4614             switch (sym.kind) {
4615             case TYP:
4616                 // For types, the computed type equals the symbol's type,
4617                 // except for two situations:
4618                 owntype = sym.type;
4619                 if (owntype.hasTag(CLASS)) {
4620                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
4621                     Type ownOuter = owntype.getEnclosingType();
4622 
4623                     // (a) If the symbol's type is parameterized, erase it
4624                     // because no type parameters were given.
4625                     // We recover generic outer type later in visitTypeApply.
4626                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
4627                         owntype = types.erasure(owntype);
4628                     }
4629 
4630                     // (b) If the symbol's type is an inner class, then
4631                     // we have to interpret its outer type as a superclass
4632                     // of the site type. Example:
4633                     //
4634                     // class Tree<A> { class Visitor { ... } }
4635                     // class PointTree extends Tree<Point> { ... }
4636                     // ...PointTree.Visitor...
4637                     //
4638                     // Then the type of the last expression above is
4639                     // Tree<Point>.Visitor.
4640                     else if (ownOuter.hasTag(CLASS) && site != ownOuter) {
4641                         Type normOuter = site;
4642                         if (normOuter.hasTag(CLASS)) {
4643                             normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
4644                         }
4645                         if (normOuter == null) // perhaps from an import
4646                             normOuter = types.erasure(ownOuter);
4647                         if (normOuter != ownOuter)
4648                             owntype = new ClassType(
4649                                 normOuter, List.nil(), owntype.tsym,
4650                                 owntype.getMetadata());
4651                     }
4652                 }
4653                 break;
4654             case VAR:
4655                 VarSymbol v = (VarSymbol)sym;
4656 
4657                 if (env.info.enclVar != null
4658                         && v.type.hasTag(NONE)) {
4659                     //self reference to implicitly typed variable declaration
4660                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
4661                     return tree.type = v.type = types.createErrorType(v.type);
4662                 }
4663 
4664                 // Test (4): if symbol is an instance field of a raw type,
4665                 // which is being assigned to, issue an unchecked warning if
4666                 // its type changes under erasure.
4667                 if (KindSelector.ASG.subset(pkind()) &&
4668                     v.owner.kind == TYP &&
4669                     (v.flags() & STATIC) == 0 &&
4670                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4671                     Type s = types.asOuterSuper(site, v.owner);
4672                     if (s != null &&
4673                         s.isRaw() &&
4674                         !types.isSameType(v.type, v.erasure(types))) {
4675                         chk.warnUnchecked(tree.pos(), Warnings.UncheckedAssignToVar(v, s));
4676                     }
4677                 }
4678                 // The computed type of a variable is the type of the
4679                 // variable symbol, taken as a member of the site type.
4680                 owntype = (sym.owner.kind == TYP &&
4681                            sym.name != names._this && sym.name != names._super)
4682                     ? types.memberType(site, sym)
4683                     : sym.type;
4684 
4685                 // If the variable is a constant, record constant value in
4686                 // computed type.
4687                 if (v.getConstValue() != null && isStaticReference(tree))
4688                     owntype = owntype.constType(v.getConstValue());
4689 
4690                 if (resultInfo.pkind == KindSelector.VAL) {
4691                     owntype = capture(owntype); // capture "names as expressions"
4692                 }
4693                 break;
4694             case MTH: {
4695                 owntype = checkMethod(site, sym,
4696                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
4697                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
4698                         resultInfo.pt.getTypeArguments());
4699                 chk.checkRestricted(tree.pos(), sym);
4700                 break;
4701             }
4702             case PCK: case ERR:
4703                 owntype = sym.type;
4704                 break;
4705             default:
4706                 throw new AssertionError("unexpected kind: " + sym.kind +
4707                                          " in tree " + tree);
4708             }
4709 
4710             // Emit a `deprecation' warning if symbol is deprecated.
4711             // (for constructors (but not for constructor references), the error
4712             // was given when the constructor was resolved)
4713 
4714             if (sym.name != names.init || tree.hasTag(REFERENCE)) {
4715                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
4716                 chk.checkSunAPI(tree.pos(), sym);
4717                 chk.checkProfile(tree.pos(), sym);
4718                 chk.checkPreview(tree.pos(), env.info.scope.owner, sym);
4719             }
4720 
4721             // If symbol is a variable, check that its type and
4722             // kind are compatible with the prototype and protokind.
4723             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
4724         }
4725 
4726         /** Check that variable is initialized and evaluate the variable's
4727          *  initializer, if not yet done. Also check that variable is not
4728          *  referenced before it is defined.
4729          *  @param tree    The tree making up the variable reference.
4730          *  @param env     The current environment.
4731          *  @param v       The variable's symbol.
4732          */
4733         private void checkInit(JCTree tree,
4734                                Env<AttrContext> env,
4735                                VarSymbol v,
4736                                boolean onlyWarning) {
4737             // A forward reference is diagnosed if the declaration position
4738             // of the variable is greater than the current tree position
4739             // and the tree and variable definition occur in the same class
4740             // definition.  Note that writes don't count as references.
4741             // This check applies only to class and instance
4742             // variables.  Local variables follow different scope rules,
4743             // and are subject to definite assignment checking.
4744             Env<AttrContext> initEnv = enclosingInitEnv(env);
4745             if (initEnv != null &&
4746                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
4747                 v.owner.kind == TYP &&
4748                 v.owner == env.info.scope.owner.enclClass() &&
4749                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
4750                 (!env.tree.hasTag(ASSIGN) ||
4751                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
4752                 if (!onlyWarning || isStaticEnumField(v)) {
4753                     Error errkey = (initEnv.info.enclVar == v) ?
4754                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
4755                     log.error(tree.pos(), errkey);
4756                 } else if (useBeforeDeclarationWarning) {
4757                     Warning warnkey = (initEnv.info.enclVar == v) ?
4758                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
4759                     log.warning(tree.pos(), warnkey);
4760                 }
4761             }
4762 
4763             v.getConstValue(); // ensure initializer is evaluated
4764 
4765             checkEnumInitializer(tree, env, v);
4766         }
4767 
4768         /**
4769          * Returns the enclosing init environment associated with this env (if any). An init env
4770          * can be either a field declaration env or a static/instance initializer env.
4771          */
4772         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
4773             while (true) {
4774                 switch (env.tree.getTag()) {
4775                     case VARDEF:
4776                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
4777                         if (vdecl.sym.owner.kind == TYP) {
4778                             //field
4779                             return env;
4780                         }
4781                         break;
4782                     case BLOCK:
4783                         if (env.next.tree.hasTag(CLASSDEF)) {
4784                             //instance/static initializer
4785                             return env;
4786                         }
4787                         break;
4788                     case METHODDEF:
4789                     case CLASSDEF:
4790                     case TOPLEVEL:
4791                         return null;
4792                 }
4793                 Assert.checkNonNull(env.next);
4794                 env = env.next;
4795             }
4796         }
4797 
4798         /**
4799          * Check for illegal references to static members of enum.  In
4800          * an enum type, constructors and initializers may not
4801          * reference its static members unless they are constant.
4802          *
4803          * @param tree    The tree making up the variable reference.
4804          * @param env     The current environment.
4805          * @param v       The variable's symbol.
4806          * @jls 8.9 Enum Types
4807          */
4808         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
4809             // JLS:
4810             //
4811             // "It is a compile-time error to reference a static field
4812             // of an enum type that is not a compile-time constant
4813             // (15.28) from constructors, instance initializer blocks,
4814             // or instance variable initializer expressions of that
4815             // type. It is a compile-time error for the constructors,
4816             // instance initializer blocks, or instance variable
4817             // initializer expressions of an enum constant e to refer
4818             // to itself or to an enum constant of the same type that
4819             // is declared to the right of e."
4820             if (isStaticEnumField(v)) {
4821                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
4822 
4823                 if (enclClass == null || enclClass.owner == null)
4824                     return;
4825 
4826                 // See if the enclosing class is the enum (or a
4827                 // subclass thereof) declaring v.  If not, this
4828                 // reference is OK.
4829                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
4830                     return;
4831 
4832                 // If the reference isn't from an initializer, then
4833                 // the reference is OK.
4834                 if (!Resolve.isInitializer(env))
4835                     return;
4836 
4837                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
4838             }
4839         }
4840 
4841         /** Is the given symbol a static, non-constant field of an Enum?
4842          *  Note: enum literals should not be regarded as such
4843          */
4844         private boolean isStaticEnumField(VarSymbol v) {
4845             return Flags.isEnum(v.owner) &&
4846                    Flags.isStatic(v) &&
4847                    !Flags.isConstant(v) &&
4848                    v.name != names._class;
4849         }
4850 
4851     /**
4852      * Check that method arguments conform to its instantiation.
4853      **/
4854     public Type checkMethod(Type site,
4855                             final Symbol sym,
4856                             ResultInfo resultInfo,
4857                             Env<AttrContext> env,
4858                             final List<JCExpression> argtrees,
4859                             List<Type> argtypes,
4860                             List<Type> typeargtypes) {
4861         // Test (5): if symbol is an instance method of a raw type, issue
4862         // an unchecked warning if its argument types change under erasure.
4863         if ((sym.flags() & STATIC) == 0 &&
4864             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4865             Type s = types.asOuterSuper(site, sym.owner);
4866             if (s != null && s.isRaw() &&
4867                 !types.isSameTypes(sym.type.getParameterTypes(),
4868                                    sym.erasure(types).getParameterTypes())) {
4869                 chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedCallMbrOfRawType(sym, s));
4870             }
4871         }
4872 
4873         if (env.info.defaultSuperCallSite != null) {
4874             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
4875                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
4876                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
4877                 List<MethodSymbol> icand_sup =
4878                         types.interfaceCandidates(sup, (MethodSymbol)sym);
4879                 if (icand_sup.nonEmpty() &&
4880                         icand_sup.head != sym &&
4881                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
4882                     log.error(env.tree.pos(),
4883                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
4884                     break;
4885                 }
4886             }
4887             env.info.defaultSuperCallSite = null;
4888         }
4889 
4890         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
4891             JCMethodInvocation app = (JCMethodInvocation)env.tree;
4892             if (app.meth.hasTag(SELECT) &&
4893                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
4894                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
4895             }
4896         }
4897 
4898         // Compute the identifier's instantiated type.
4899         // For methods, we need to compute the instance type by
4900         // Resolve.instantiate from the symbol's type as well as
4901         // any type arguments and value arguments.
4902         Warner noteWarner = new Warner();
4903         try {
4904             Type owntype = rs.checkMethod(
4905                     env,
4906                     site,
4907                     sym,
4908                     resultInfo,
4909                     argtypes,
4910                     typeargtypes,
4911                     noteWarner);
4912 
4913             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
4914                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
4915 
4916             argtypes = argtypes.map(checkDeferredMap);
4917 
4918             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
4919                 chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedMethInvocationApplied(kindName(sym),
4920                         sym.name,
4921                         rs.methodArguments(sym.type.getParameterTypes()),
4922                         rs.methodArguments(argtypes.map(checkDeferredMap)),
4923                         kindName(sym.location()),
4924                         sym.location()));
4925                 if (resultInfo.pt != Infer.anyPoly ||
4926                         !owntype.hasTag(METHOD) ||
4927                         !owntype.isPartial()) {
4928                     //if this is not a partially inferred method type, erase return type. Otherwise,
4929                     //erasure is carried out in PartiallyInferredMethodType.check().
4930                     owntype = new MethodType(owntype.getParameterTypes(),
4931                             types.erasure(owntype.getReturnType()),
4932                             types.erasure(owntype.getThrownTypes()),
4933                             syms.methodClass);
4934                 }
4935             }
4936 
4937             PolyKind pkind = (sym.type.hasTag(FORALL) &&
4938                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
4939                  PolyKind.POLY : PolyKind.STANDALONE;
4940             TreeInfo.setPolyKind(env.tree, pkind);
4941 
4942             return (resultInfo.pt == Infer.anyPoly) ?
4943                     owntype :
4944                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
4945                             resultInfo.checkContext.inferenceContext());
4946         } catch (Infer.InferenceException ex) {
4947             //invalid target type - propagate exception outwards or report error
4948             //depending on the current check context
4949             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
4950             return types.createErrorType(site);
4951         } catch (Resolve.InapplicableMethodException ex) {
4952             final JCDiagnostic diag = ex.getDiagnostic();
4953             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
4954                 @Override
4955                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
4956                     return new Pair<>(sym, diag);
4957                 }
4958             };
4959             List<Type> argtypes2 = argtypes.map(
4960                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
4961             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
4962                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
4963             log.report(errDiag);
4964             return types.createErrorType(site);
4965         }
4966     }
4967 
4968     public void visitLiteral(JCLiteral tree) {
4969         result = check(tree, litType(tree.typetag).constType(tree.value),
4970                 KindSelector.VAL, resultInfo);
4971     }
4972     //where
4973     /** Return the type of a literal with given type tag.
4974      */
4975     Type litType(TypeTag tag) {
4976         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
4977     }
4978 
4979     public void visitStringTemplate(JCStringTemplate tree) {
4980         JCExpression processor = tree.processor;
4981         Type processorType = attribTree(processor, env, new ResultInfo(KindSelector.VAL, Type.noType));
4982         chk.checkProcessorType(processor, processorType, env);
4983         Type processMethodType = getProcessMethodType(tree, processorType);
4984         tree.processMethodType = processMethodType;
4985         Type resultType = processMethodType.getReturnType();
4986 
4987         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
4988 
4989         for (JCExpression arg : tree.expressions) {
4990             chk.checkNonVoid(arg.pos(), attribExpr(arg, localEnv));
4991         }
4992 
4993         tree.type = resultType;
4994         result = resultType;
4995         check(tree, resultType, KindSelector.VAL, resultInfo);
4996     }
4997 
4998     private Type getProcessMethodType(JCStringTemplate tree, Type processorType) {
4999         MethodSymbol processSymbol = rs.resolveInternalMethod(tree.pos(),
5000                 env, types.skipTypeVars(processorType, false),
5001                 names.process, List.of(syms.stringTemplateType), List.nil());
5002         return types.memberType(processorType, processSymbol);
5003     }
5004 
5005     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5006         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5007     }
5008 
5009     public void visitTypeArray(JCArrayTypeTree tree) {
5010         Type etype = attribType(tree.elemtype, env);
5011         Type type = new ArrayType(etype, syms.arrayClass);
5012         result = check(tree, type, KindSelector.TYP, resultInfo);
5013     }
5014 
5015     /** Visitor method for parameterized types.
5016      *  Bound checking is left until later, since types are attributed
5017      *  before supertype structure is completely known
5018      */
5019     public void visitTypeApply(JCTypeApply tree) {
5020         Type owntype = types.createErrorType(tree.type);
5021 
5022         // Attribute functor part of application and make sure it's a class.
5023         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5024 
5025         // Attribute type parameters
5026         List<Type> actuals = attribTypes(tree.arguments, env);
5027 
5028         if (clazztype.hasTag(CLASS)) {
5029             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5030             if (actuals.isEmpty()) //diamond
5031                 actuals = formals;
5032 
5033             if (actuals.length() == formals.length()) {
5034                 List<Type> a = actuals;
5035                 List<Type> f = formals;
5036                 while (a.nonEmpty()) {
5037                     a.head = a.head.withTypeVar(f.head);
5038                     a = a.tail;
5039                     f = f.tail;
5040                 }
5041                 // Compute the proper generic outer
5042                 Type clazzOuter = clazztype.getEnclosingType();
5043                 if (clazzOuter.hasTag(CLASS)) {
5044                     Type site;
5045                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5046                     if (clazz.hasTag(IDENT)) {
5047                         site = env.enclClass.sym.type;
5048                     } else if (clazz.hasTag(SELECT)) {
5049                         site = ((JCFieldAccess) clazz).selected.type;
5050                     } else throw new AssertionError(""+tree);
5051                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5052                         if (site.hasTag(CLASS))
5053                             site = types.asOuterSuper(site, clazzOuter.tsym);
5054                         if (site == null)
5055                             site = types.erasure(clazzOuter);
5056                         clazzOuter = site;
5057                     }
5058                 }
5059                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5060                                         clazztype.getMetadata());
5061             } else {
5062                 if (formals.length() != 0) {
5063                     log.error(tree.pos(),
5064                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5065                 } else {
5066                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5067                 }
5068                 owntype = types.createErrorType(tree.type);
5069             }
5070         }
5071         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5072     }
5073 
5074     public void visitTypeUnion(JCTypeUnion tree) {
5075         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5076         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5077         for (JCExpression typeTree : tree.alternatives) {
5078             Type ctype = attribType(typeTree, env);
5079             ctype = chk.checkType(typeTree.pos(),
5080                           chk.checkClassType(typeTree.pos(), ctype),
5081                           syms.throwableType);
5082             if (!ctype.isErroneous()) {
5083                 //check that alternatives of a union type are pairwise
5084                 //unrelated w.r.t. subtyping
5085                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5086                     for (Type t : multicatchTypes) {
5087                         boolean sub = types.isSubtype(ctype, t);
5088                         boolean sup = types.isSubtype(t, ctype);
5089                         if (sub || sup) {
5090                             //assume 'a' <: 'b'
5091                             Type a = sub ? ctype : t;
5092                             Type b = sub ? t : ctype;
5093                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5094                         }
5095                     }
5096                 }
5097                 multicatchTypes.append(ctype);
5098                 if (all_multicatchTypes != null)
5099                     all_multicatchTypes.append(ctype);
5100             } else {
5101                 if (all_multicatchTypes == null) {
5102                     all_multicatchTypes = new ListBuffer<>();
5103                     all_multicatchTypes.appendList(multicatchTypes);
5104                 }
5105                 all_multicatchTypes.append(ctype);
5106             }
5107         }
5108         Type t = check(tree, types.lub(multicatchTypes.toList()),
5109                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5110         if (t.hasTag(CLASS)) {
5111             List<Type> alternatives =
5112                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5113             t = new UnionClassType((ClassType) t, alternatives);
5114         }
5115         tree.type = result = t;
5116     }
5117 
5118     public void visitTypeIntersection(JCTypeIntersection tree) {
5119         attribTypes(tree.bounds, env);
5120         tree.type = result = checkIntersection(tree, tree.bounds);
5121     }
5122 
5123     public void visitTypeParameter(JCTypeParameter tree) {
5124         TypeVar typeVar = (TypeVar) tree.type;
5125 
5126         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5127             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5128         }
5129 
5130         if (!typeVar.getUpperBound().isErroneous()) {
5131             //fixup type-parameter bound computed in 'attribTypeVariables'
5132             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5133         }
5134     }
5135 
5136     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5137         Set<Symbol> boundSet = new HashSet<>();
5138         if (bounds.nonEmpty()) {
5139             // accept class or interface or typevar as first bound.
5140             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5141             boundSet.add(types.erasure(bounds.head.type).tsym);
5142             if (bounds.head.type.isErroneous()) {
5143                 return bounds.head.type;
5144             }
5145             else if (bounds.head.type.hasTag(TYPEVAR)) {
5146                 // if first bound was a typevar, do not accept further bounds.
5147                 if (bounds.tail.nonEmpty()) {
5148                     log.error(bounds.tail.head.pos(),
5149                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5150                     return bounds.head.type;
5151                 }
5152             } else {
5153                 // if first bound was a class or interface, accept only interfaces
5154                 // as further bounds.
5155                 for (JCExpression bound : bounds.tail) {
5156                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5157                     if (bound.type.isErroneous()) {
5158                         bounds = List.of(bound);
5159                     }
5160                     else if (bound.type.hasTag(CLASS)) {
5161                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5162                     }
5163                 }
5164             }
5165         }
5166 
5167         if (bounds.length() == 0) {
5168             return syms.objectType;
5169         } else if (bounds.length() == 1) {
5170             return bounds.head.type;
5171         } else {
5172             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5173             // ... the variable's bound is a class type flagged COMPOUND
5174             // (see comment for TypeVar.bound).
5175             // In this case, generate a class tree that represents the
5176             // bound class, ...
5177             JCExpression extending;
5178             List<JCExpression> implementing;
5179             if (!bounds.head.type.isInterface()) {
5180                 extending = bounds.head;
5181                 implementing = bounds.tail;
5182             } else {
5183                 extending = null;
5184                 implementing = bounds;
5185             }
5186             JCClassDecl cd = make.at(tree).ClassDef(
5187                 make.Modifiers(PUBLIC | ABSTRACT),
5188                 names.empty, List.nil(),
5189                 extending, implementing, List.nil());
5190 
5191             ClassSymbol c = (ClassSymbol)owntype.tsym;
5192             Assert.check((c.flags() & COMPOUND) != 0);
5193             cd.sym = c;
5194             c.sourcefile = env.toplevel.sourcefile;
5195 
5196             // ... and attribute the bound class
5197             c.flags_field |= UNATTRIBUTED;
5198             Env<AttrContext> cenv = enter.classEnv(cd, env);
5199             typeEnvs.put(c, cenv);
5200             attribClass(c);
5201             return owntype;
5202         }
5203     }
5204 
5205     public void visitWildcard(JCWildcard tree) {
5206         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5207         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5208             ? syms.objectType
5209             : attribType(tree.inner, env);
5210         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
5211                                               tree.kind.kind,
5212                                               syms.boundClass),
5213                 KindSelector.TYP, resultInfo);
5214     }
5215 
5216     public void visitAnnotation(JCAnnotation tree) {
5217         Assert.error("should be handled in annotate");
5218     }
5219 
5220     @Override
5221     public void visitModifiers(JCModifiers tree) {
5222         //error recovery only:
5223         Assert.check(resultInfo.pkind == KindSelector.ERR);
5224 
5225         attribAnnotationTypes(tree.annotations, env);
5226     }
5227 
5228     public void visitAnnotatedType(JCAnnotatedType tree) {
5229         attribAnnotationTypes(tree.annotations, env);
5230         Type underlyingType = attribType(tree.underlyingType, env);
5231         Type annotatedType = underlyingType.preannotatedType();
5232 
5233         if (!env.info.isNewClass)
5234             annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5235         result = tree.type = annotatedType;
5236     }
5237 
5238     public void visitErroneous(JCErroneous tree) {
5239         if (tree.errs != null) {
5240             Env<AttrContext> errEnv = env.dup(env.tree, env.info.dup());
5241             errEnv.info.returnResult = unknownExprInfo;
5242             for (JCTree err : tree.errs)
5243                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5244         }
5245         result = tree.type = syms.errType;
5246     }
5247 
5248     /** Default visitor method for all other trees.
5249      */
5250     public void visitTree(JCTree tree) {
5251         throw new AssertionError();
5252     }
5253 
5254     /**
5255      * Attribute an env for either a top level tree or class or module declaration.
5256      */
5257     public void attrib(Env<AttrContext> env) {
5258         switch (env.tree.getTag()) {
5259             case MODULEDEF:
5260                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5261                 break;
5262             case PACKAGEDEF:
5263                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5264                 break;
5265             default:
5266                 attribClass(env.tree.pos(), env.enclClass.sym);
5267         }
5268     }
5269 
5270     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5271         try {
5272             annotate.flush();
5273             attribPackage(p);
5274         } catch (CompletionFailure ex) {
5275             chk.completionError(pos, ex);
5276         }
5277     }
5278 
5279     void attribPackage(PackageSymbol p) {
5280         attribWithLint(p,
5281                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5282     }
5283 
5284     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5285         try {
5286             annotate.flush();
5287             attribModule(m);
5288         } catch (CompletionFailure ex) {
5289             chk.completionError(pos, ex);
5290         }
5291     }
5292 
5293     void attribModule(ModuleSymbol m) {
5294         attribWithLint(m, env -> attribStat(env.tree, env));
5295     }
5296 
5297     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5298         Env<AttrContext> env = typeEnvs.get(sym);
5299 
5300         Env<AttrContext> lintEnv = env;
5301         while (lintEnv.info.lint == null)
5302             lintEnv = lintEnv.next;
5303 
5304         Lint lint = lintEnv.info.lint.augment(sym);
5305 
5306         Lint prevLint = chk.setLint(lint);
5307         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5308 
5309         try {
5310             deferredLintHandler.flush(env.tree.pos());
5311             attrib.accept(env);
5312         } finally {
5313             log.useSource(prev);
5314             chk.setLint(prevLint);
5315         }
5316     }
5317 
5318     /** Main method: attribute class definition associated with given class symbol.
5319      *  reporting completion failures at the given position.
5320      *  @param pos The source position at which completion errors are to be
5321      *             reported.
5322      *  @param c   The class symbol whose definition will be attributed.
5323      */
5324     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5325         try {
5326             annotate.flush();
5327             attribClass(c);
5328         } catch (CompletionFailure ex) {
5329             chk.completionError(pos, ex);
5330         }
5331     }
5332 
5333     /** Attribute class definition associated with given class symbol.
5334      *  @param c   The class symbol whose definition will be attributed.
5335      */
5336     void attribClass(ClassSymbol c) throws CompletionFailure {
5337         if (c.type.hasTag(ERROR)) return;
5338 
5339         // Check for cycles in the inheritance graph, which can arise from
5340         // ill-formed class files.
5341         chk.checkNonCyclic(null, c.type);
5342 
5343         Type st = types.supertype(c.type);
5344         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5345             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0) {
5346             // First, attribute superclass.
5347             if (st.hasTag(CLASS))
5348                 attribClass((ClassSymbol)st.tsym);
5349 
5350             // Next attribute owner, if it is a class.
5351             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5352                 attribClass((ClassSymbol)c.owner);
5353 
5354             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5355         }
5356 
5357         // The previous operations might have attributed the current class
5358         // if there was a cycle. So we test first whether the class is still
5359         // UNATTRIBUTED.
5360         if ((c.flags_field & UNATTRIBUTED) != 0) {
5361             c.flags_field &= ~UNATTRIBUTED;
5362 
5363             // Get environment current at the point of class definition.
5364             Env<AttrContext> env = typeEnvs.get(c);
5365 
5366             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5367             // because the annotations were not available at the time the env was created. Therefore,
5368             // we look up the environment chain for the first enclosing environment for which the
5369             // lint value is set. Typically, this is the parent env, but might be further if there
5370             // are any envs created as a result of TypeParameter nodes.
5371             Env<AttrContext> lintEnv = env;
5372             while (lintEnv.info.lint == null)
5373                 lintEnv = lintEnv.next;
5374 
5375             // Having found the enclosing lint value, we can initialize the lint value for this class
5376             env.info.lint = lintEnv.info.lint.augment(c);
5377 
5378             Lint prevLint = chk.setLint(env.info.lint);
5379             JavaFileObject prev = log.useSource(c.sourcefile);
5380             ResultInfo prevReturnRes = env.info.returnResult;
5381 
5382             try {
5383                 if (c.isSealed() &&
5384                         !c.isEnum() &&
5385                         !c.isPermittedExplicit &&
5386                         c.permitted.isEmpty()) {
5387                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5388                 }
5389 
5390                 if (c.isSealed()) {
5391                     Set<Symbol> permittedTypes = new HashSet<>();
5392                     boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5393                     for (Symbol subTypeSym : c.permitted) {
5394                         boolean isTypeVar = false;
5395                         if (subTypeSym.type.getTag() == TYPEVAR) {
5396                             isTypeVar = true; //error recovery
5397                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5398                                     Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subTypeSym.type)));
5399                         }
5400                         if (subTypeSym.isAnonymous() && !c.isEnum()) {
5401                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5402                         }
5403                         if (permittedTypes.contains(subTypeSym)) {
5404                             DiagnosticPosition pos =
5405                                     env.enclClass.permitting.stream()
5406                                             .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subTypeSym, permittedExpr, true) != null)
5407                                             .limit(2).collect(List.collector()).get(1);
5408                             log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subTypeSym.type)));
5409                         } else {
5410                             permittedTypes.add(subTypeSym);
5411                         }
5412                         if (sealedInUnnamed) {
5413                             if (subTypeSym.packge() != c.packge()) {
5414                                 log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5415                                         Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5416                                 );
5417                             }
5418                         } else if (subTypeSym.packge().modle != c.packge().modle) {
5419                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5420                                     Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5421                             );
5422                         }
5423                         if (subTypeSym == c.type.tsym || types.isSuperType(subTypeSym.type, c.type)) {
5424                             log.error(TreeInfo.diagnosticPositionFor(subTypeSym, ((JCClassDecl)env.tree).permitting),
5425                                     Errors.InvalidPermitsClause(
5426                                             subTypeSym == c.type.tsym ?
5427                                                     Fragments.MustNotBeSameClass :
5428                                                     Fragments.MustNotBeSupertype(subTypeSym.type)
5429                                     )
5430                             );
5431                         } else if (!isTypeVar) {
5432                             boolean thisIsASuper = types.directSupertypes(subTypeSym.type)
5433                                                         .stream()
5434                                                         .anyMatch(d -> d.tsym == c);
5435                             if (!thisIsASuper) {
5436                                 log.error(TreeInfo.diagnosticPositionFor(subTypeSym, env.tree),
5437                                         Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subTypeSym.type)));
5438                             }
5439                         }
5440                     }
5441                 }
5442 
5443                 List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5444                                                       .stream()
5445                                                       .filter(s -> s.tsym.isSealed())
5446                                                       .map(s -> (ClassSymbol) s.tsym)
5447                                                       .collect(List.collector());
5448 
5449                 if (sealedSupers.isEmpty()) {
5450                     if ((c.flags_field & Flags.NON_SEALED) != 0) {
5451                         boolean hasErrorSuper = false;
5452 
5453                         hasErrorSuper |= types.directSupertypes(c.type)
5454                                               .stream()
5455                                               .anyMatch(s -> s.tsym.kind == Kind.ERR);
5456 
5457                         ClassType ct = (ClassType) c.type;
5458 
5459                         hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5460 
5461                         if (!hasErrorSuper) {
5462                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5463                         }
5464                     }
5465                 } else {
5466                     if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5467                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5468                     }
5469 
5470                     if (!c.type.isCompound()) {
5471                         for (ClassSymbol supertypeSym : sealedSupers) {
5472                             if (!supertypeSym.permitted.contains(c.type.tsym)) {
5473                                 log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5474                             }
5475                         }
5476                         if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5477                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5478                                     c.isInterface() ?
5479                                             Errors.NonSealedOrSealedExpected :
5480                                             Errors.NonSealedSealedOrFinalExpected);
5481                         }
5482                     }
5483                 }
5484 
5485                 deferredLintHandler.flush(env.tree);
5486                 env.info.returnResult = null;
5487                 // java.lang.Enum may not be subclassed by a non-enum
5488                 if (st.tsym == syms.enumSym &&
5489                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5490                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5491 
5492                 // Enums may not be extended by source-level classes
5493                 if (st.tsym != null &&
5494                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5495                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5496                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5497                 }
5498 
5499                 if (rs.isSerializable(c.type)) {
5500                     env.info.isSerializable = true;
5501                 }
5502 





5503                 attribClassBody(env, c);
5504 
5505                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5506                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5507                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5508                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5509 
5510                 if (c.isImplicit()) {
5511                     chk.checkHasMain(env.tree.pos(), c);
5512                 }
5513             } finally {
5514                 env.info.returnResult = prevReturnRes;
5515                 log.useSource(prev);
5516                 chk.setLint(prevLint);
5517             }
5518 
5519         }
5520     }
5521 
5522     public void visitImport(JCImport tree) {
5523         // nothing to do
5524     }
5525 
5526     public void visitModuleDef(JCModuleDecl tree) {
5527         tree.sym.completeUsesProvides();
5528         ModuleSymbol msym = tree.sym;
5529         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5530         Lint prevLint = chk.setLint(lint);
5531         chk.checkModuleName(tree);
5532         chk.checkDeprecatedAnnotation(tree, msym);
5533 
5534         try {
5535             deferredLintHandler.flush(tree.pos());
5536         } finally {
5537             chk.setLint(prevLint);
5538         }
5539     }
5540 
5541     /** Finish the attribution of a class. */
5542     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5543         JCClassDecl tree = (JCClassDecl)env.tree;
5544         Assert.check(c == tree.sym);
5545 
5546         // Validate type parameters, supertype and interfaces.
5547         attribStats(tree.typarams, env);
5548         if (!c.isAnonymous()) {
5549             //already checked if anonymous
5550             chk.validate(tree.typarams, env);
5551             chk.validate(tree.extending, env);
5552             chk.validate(tree.implementing, env);
5553         }
5554 
5555         c.markAbstractIfNeeded(types);
5556 
5557         // If this is a non-abstract class, check that it has no abstract
5558         // methods or unimplemented methods of an implemented interface.
5559         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
5560             chk.checkAllDefined(tree.pos(), c);
5561         }
5562 
5563         if ((c.flags() & ANNOTATION) != 0) {
5564             if (tree.implementing.nonEmpty())
5565                 log.error(tree.implementing.head.pos(),
5566                           Errors.CantExtendIntfAnnotation);
5567             if (tree.typarams.nonEmpty()) {
5568                 log.error(tree.typarams.head.pos(),
5569                           Errors.IntfAnnotationCantHaveTypeParams(c));
5570             }
5571 
5572             // If this annotation type has a @Repeatable, validate
5573             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
5574             // If this annotation type has a @Repeatable, validate
5575             if (repeatable != null) {
5576                 // get diagnostic position for error reporting
5577                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
5578                 Assert.checkNonNull(cbPos);
5579 
5580                 chk.validateRepeatable(c, repeatable, cbPos);
5581             }
5582         } else {
5583             // Check that all extended classes and interfaces
5584             // are compatible (i.e. no two define methods with same arguments
5585             // yet different return types).  (JLS 8.4.8.3)
5586             chk.checkCompatibleSupertypes(tree.pos(), c.type);
5587             chk.checkDefaultMethodClashes(tree.pos(), c.type);
5588             chk.checkPotentiallyAmbiguousOverloads(tree, c.type);
5589         }
5590 
5591         // Check that class does not import the same parameterized interface
5592         // with two different argument lists.
5593         chk.checkClassBounds(tree.pos(), c.type);
5594 
5595         tree.type = c.type;
5596 
5597         for (List<JCTypeParameter> l = tree.typarams;
5598              l.nonEmpty(); l = l.tail) {
5599              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
5600         }
5601 
5602         // Check that a generic class doesn't extend Throwable
5603         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
5604             log.error(tree.extending.pos(), Errors.GenericThrowable);
5605 
5606         // Check that all methods which implement some
5607         // method conform to the method they implement.
5608         chk.checkImplementations(tree);
5609 
5610         //check that a resource implementing AutoCloseable cannot throw InterruptedException
5611         checkAutoCloseable(tree.pos(), env, c.type);
5612 
5613         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
5614             // Attribute declaration
5615             attribStat(l.head, env);
5616             // Check that declarations in inner classes are not static (JLS 8.1.2)
5617             // Make an exception for static constants.
5618             if (!allowRecords &&
5619                     c.owner.kind != PCK &&
5620                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
5621                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
5622                 VarSymbol sym = null;
5623                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
5624                 if (sym == null ||
5625                         sym.kind != VAR ||
5626                         sym.getConstValue() == null)
5627                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
5628             }
5629         }
5630 
5631         // Check for proper placement of super()/this() calls.
5632         chk.checkSuperInitCalls(tree);
5633 
5634         // Check for cycles among non-initial constructors.
5635         chk.checkCyclicConstructors(tree);
5636 
5637         // Check for cycles among annotation elements.
5638         chk.checkNonCyclicElements(tree);
5639 
5640         // Check for proper use of serialVersionUID and other
5641         // serialization-related fields and methods
5642         if (env.info.lint.isEnabled(LintCategory.SERIAL)
5643                 && rs.isSerializable(c.type)
5644                 && !c.isAnonymous()) {
5645             chk.checkSerialStructure(tree, c);
5646         }
5647         // Correctly organize the positions of the type annotations
5648         typeAnnotations.organizeTypeAnnotationsBodies(tree);
5649 
5650         // Check type annotations applicability rules
5651         validateTypeAnnotations(tree, false);
5652     }
5653         // where
5654         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
5655         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
5656             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
5657                 if (types.isSameType(al.head.annotationType.type, t))
5658                     return al.head.pos();
5659             }
5660 
5661             return null;
5662         }
5663 
5664     private Type capture(Type type) {
5665         return types.capture(type);
5666     }
5667 
5668     private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
5669         if (type.isErroneous()) {
5670             tree.vartype = make.at(Position.NOPOS).Erroneous();
5671         } else {
5672             tree.vartype = make.at(Position.NOPOS).Type(type);
5673         }
5674     }
5675 
5676     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
5677         tree.accept(new TypeAnnotationsValidator(sigOnly));
5678     }
5679     //where
5680     private final class TypeAnnotationsValidator extends TreeScanner {
5681 
5682         private final boolean sigOnly;
5683         public TypeAnnotationsValidator(boolean sigOnly) {
5684             this.sigOnly = sigOnly;
5685         }
5686 
5687         public void visitAnnotation(JCAnnotation tree) {
5688             chk.validateTypeAnnotation(tree, null, false);
5689             super.visitAnnotation(tree);
5690         }
5691         public void visitAnnotatedType(JCAnnotatedType tree) {
5692             if (!tree.underlyingType.type.isErroneous()) {
5693                 super.visitAnnotatedType(tree);
5694             }
5695         }
5696         public void visitTypeParameter(JCTypeParameter tree) {
5697             chk.validateTypeAnnotations(tree.annotations, tree.type.tsym, true);
5698             scan(tree.bounds);
5699             // Don't call super.
5700             // This is needed because above we call validateTypeAnnotation with
5701             // false, which would forbid annotations on type parameters.
5702             // super.visitTypeParameter(tree);
5703         }
5704         public void visitMethodDef(JCMethodDecl tree) {
5705             if (tree.recvparam != null &&
5706                     !tree.recvparam.vartype.type.isErroneous()) {
5707                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
5708             }
5709             if (tree.restype != null && tree.restype.type != null) {
5710                 validateAnnotatedType(tree.restype, tree.restype.type);
5711             }
5712             if (sigOnly) {
5713                 scan(tree.mods);
5714                 scan(tree.restype);
5715                 scan(tree.typarams);
5716                 scan(tree.recvparam);
5717                 scan(tree.params);
5718                 scan(tree.thrown);
5719             } else {
5720                 scan(tree.defaultValue);
5721                 scan(tree.body);
5722             }
5723         }
5724         public void visitVarDef(final JCVariableDecl tree) {
5725             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
5726             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
5727                 validateAnnotatedType(tree.vartype, tree.sym.type);
5728             scan(tree.mods);
5729             scan(tree.vartype);
5730             if (!sigOnly) {
5731                 scan(tree.init);
5732             }
5733         }
5734         public void visitTypeCast(JCTypeCast tree) {
5735             if (tree.clazz != null && tree.clazz.type != null)
5736                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5737             super.visitTypeCast(tree);
5738         }
5739         public void visitTypeTest(JCInstanceOf tree) {
5740             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
5741                 validateAnnotatedType(tree.pattern, tree.pattern.type);
5742             super.visitTypeTest(tree);
5743         }
5744         public void visitNewClass(JCNewClass tree) {
5745             if (tree.clazz != null && tree.clazz.type != null) {
5746                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
5747                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
5748                             tree.clazz.type.tsym);
5749                 }
5750                 if (tree.def != null) {
5751                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
5752                 }
5753 
5754                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5755             }
5756             super.visitNewClass(tree);
5757         }
5758         public void visitNewArray(JCNewArray tree) {
5759             if (tree.elemtype != null && tree.elemtype.type != null) {
5760                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
5761                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
5762                             tree.elemtype.type.tsym);
5763                 }
5764                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
5765             }
5766             super.visitNewArray(tree);
5767         }
5768         public void visitClassDef(JCClassDecl tree) {
5769             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
5770             if (sigOnly) {
5771                 scan(tree.mods);
5772                 scan(tree.typarams);
5773                 scan(tree.extending);
5774                 scan(tree.implementing);
5775             }
5776             for (JCTree member : tree.defs) {
5777                 if (member.hasTag(Tag.CLASSDEF)) {
5778                     continue;
5779                 }
5780                 scan(member);
5781             }
5782         }
5783         public void visitBlock(JCBlock tree) {
5784             if (!sigOnly) {
5785                 scan(tree.stats);
5786             }
5787         }
5788 
5789         /* I would want to model this after
5790          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
5791          * and override visitSelect and visitTypeApply.
5792          * However, we only set the annotated type in the top-level type
5793          * of the symbol.
5794          * Therefore, we need to override each individual location where a type
5795          * can occur.
5796          */
5797         private void validateAnnotatedType(final JCTree errtree, final Type type) {
5798             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
5799 
5800             if (type.isPrimitiveOrVoid()) {
5801                 return;
5802             }
5803 
5804             JCTree enclTr = errtree;
5805             Type enclTy = type;
5806 
5807             boolean repeat = true;
5808             while (repeat) {
5809                 if (enclTr.hasTag(TYPEAPPLY)) {
5810                     List<Type> tyargs = enclTy.getTypeArguments();
5811                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
5812                     if (trargs.length() > 0) {
5813                         // Nothing to do for diamonds
5814                         if (tyargs.length() == trargs.length()) {
5815                             for (int i = 0; i < tyargs.length(); ++i) {
5816                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
5817                             }
5818                         }
5819                         // If the lengths don't match, it's either a diamond
5820                         // or some nested type that redundantly provides
5821                         // type arguments in the tree.
5822                     }
5823 
5824                     // Look at the clazz part of a generic type
5825                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
5826                 }
5827 
5828                 if (enclTr.hasTag(SELECT)) {
5829                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
5830                     if (enclTy != null &&
5831                             !enclTy.hasTag(NONE)) {
5832                         enclTy = enclTy.getEnclosingType();
5833                     }
5834                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
5835                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
5836                     if (enclTy == null || enclTy.hasTag(NONE)) {
5837                         if (at.getAnnotations().size() == 1) {
5838                             log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping1(at.getAnnotations().head.attribute));
5839                         } else {
5840                             ListBuffer<Attribute.Compound> comps = new ListBuffer<>();
5841                             for (JCAnnotation an : at.getAnnotations()) {
5842                                 comps.add(an.attribute);
5843                             }
5844                             log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping(comps.toList()));
5845                         }
5846                         repeat = false;
5847                     }
5848                     enclTr = at.underlyingType;
5849                     // enclTy doesn't need to be changed
5850                 } else if (enclTr.hasTag(IDENT)) {
5851                     repeat = false;
5852                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
5853                     JCWildcard wc = (JCWildcard) enclTr;
5854                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
5855                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
5856                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
5857                     } else {
5858                         // Nothing to do for UNBOUND
5859                     }
5860                     repeat = false;
5861                 } else if (enclTr.hasTag(TYPEARRAY)) {
5862                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
5863                     validateAnnotatedType(art.getType(), art.elemtype.type);
5864                     repeat = false;
5865                 } else if (enclTr.hasTag(TYPEUNION)) {
5866                     JCTypeUnion ut = (JCTypeUnion) enclTr;
5867                     for (JCTree t : ut.getTypeAlternatives()) {
5868                         validateAnnotatedType(t, t.type);
5869                     }
5870                     repeat = false;
5871                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
5872                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
5873                     for (JCTree t : it.getBounds()) {
5874                         validateAnnotatedType(t, t.type);
5875                     }
5876                     repeat = false;
5877                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
5878                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
5879                     repeat = false;
5880                 } else {
5881                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
5882                             " within: "+ errtree + " with kind: " + errtree.getKind());
5883                 }
5884             }
5885         }
5886 
5887         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
5888                 Symbol sym) {
5889             // Ensure that no declaration annotations are present.
5890             // Note that a tree type might be an AnnotatedType with
5891             // empty annotations, if only declaration annotations were given.
5892             // This method will raise an error for such a type.
5893             for (JCAnnotation ai : annotations) {
5894                 if (!ai.type.isErroneous() &&
5895                         typeAnnotations.annotationTargetType(ai, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
5896                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
5897                 }
5898             }
5899         }
5900     }
5901 
5902     // <editor-fold desc="post-attribution visitor">
5903 
5904     /**
5905      * Handle missing types/symbols in an AST. This routine is useful when
5906      * the compiler has encountered some errors (which might have ended up
5907      * terminating attribution abruptly); if the compiler is used in fail-over
5908      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
5909      * prevents NPE to be propagated during subsequent compilation steps.
5910      */
5911     public void postAttr(JCTree tree) {
5912         new PostAttrAnalyzer().scan(tree);
5913     }
5914 
5915     class PostAttrAnalyzer extends TreeScanner {
5916 
5917         private void initTypeIfNeeded(JCTree that) {
5918             if (that.type == null) {
5919                 if (that.hasTag(METHODDEF)) {
5920                     that.type = dummyMethodType((JCMethodDecl)that);
5921                 } else {
5922                     that.type = syms.unknownType;
5923                 }
5924             }
5925         }
5926 
5927         /* Construct a dummy method type. If we have a method declaration,
5928          * and the declared return type is void, then use that return type
5929          * instead of UNKNOWN to avoid spurious error messages in lambda
5930          * bodies (see:JDK-8041704).
5931          */
5932         private Type dummyMethodType(JCMethodDecl md) {
5933             Type restype = syms.unknownType;
5934             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
5935                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
5936                 if (prim.typetag == VOID)
5937                     restype = syms.voidType;
5938             }
5939             return new MethodType(List.nil(), restype,
5940                                   List.nil(), syms.methodClass);
5941         }
5942         private Type dummyMethodType() {
5943             return dummyMethodType(null);
5944         }
5945 
5946         @Override
5947         public void scan(JCTree tree) {
5948             if (tree == null) return;
5949             if (tree instanceof JCExpression) {
5950                 initTypeIfNeeded(tree);
5951             }
5952             super.scan(tree);
5953         }
5954 
5955         @Override
5956         public void visitIdent(JCIdent that) {
5957             if (that.sym == null) {
5958                 that.sym = syms.unknownSymbol;
5959             }
5960         }
5961 
5962         @Override
5963         public void visitSelect(JCFieldAccess that) {
5964             if (that.sym == null) {
5965                 that.sym = syms.unknownSymbol;
5966             }
5967             super.visitSelect(that);
5968         }
5969 
5970         @Override
5971         public void visitClassDef(JCClassDecl that) {
5972             initTypeIfNeeded(that);
5973             if (that.sym == null) {
5974                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
5975             }
5976             super.visitClassDef(that);
5977         }
5978 
5979         @Override
5980         public void visitMethodDef(JCMethodDecl that) {
5981             initTypeIfNeeded(that);
5982             if (that.sym == null) {
5983                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
5984             }
5985             super.visitMethodDef(that);
5986         }
5987 
5988         @Override
5989         public void visitVarDef(JCVariableDecl that) {
5990             initTypeIfNeeded(that);
5991             if (that.sym == null) {
5992                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
5993                 that.sym.adr = 0;
5994             }
5995             if (that.vartype == null) {
5996                 that.vartype = make.at(Position.NOPOS).Erroneous();
5997             }
5998             super.visitVarDef(that);
5999         }
6000 
6001         @Override
6002         public void visitBindingPattern(JCBindingPattern that) {
6003             initTypeIfNeeded(that);
6004             initTypeIfNeeded(that.var);
6005             if (that.var.sym == null) {
6006                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6007                 that.var.sym.adr = 0;
6008             }
6009             super.visitBindingPattern(that);
6010         }
6011 
6012         @Override
6013         public void visitNewClass(JCNewClass that) {
6014             if (that.constructor == null) {
6015                 that.constructor = new MethodSymbol(0, names.init,
6016                         dummyMethodType(), syms.noSymbol);
6017             }
6018             if (that.constructorType == null) {
6019                 that.constructorType = syms.unknownType;
6020             }
6021             super.visitNewClass(that);
6022         }
6023 
6024         @Override
6025         public void visitAssignop(JCAssignOp that) {
6026             if (that.operator == null) {
6027                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6028                         -1, syms.noSymbol);
6029             }
6030             super.visitAssignop(that);
6031         }
6032 
6033         @Override
6034         public void visitBinary(JCBinary that) {
6035             if (that.operator == null) {
6036                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6037                         -1, syms.noSymbol);
6038             }
6039             super.visitBinary(that);
6040         }
6041 
6042         @Override
6043         public void visitUnary(JCUnary that) {
6044             if (that.operator == null) {
6045                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6046                         -1, syms.noSymbol);
6047             }
6048             super.visitUnary(that);
6049         }
6050 
6051         @Override
6052         public void visitReference(JCMemberReference that) {
6053             super.visitReference(that);
6054             if (that.sym == null) {
6055                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6056                         syms.noSymbol);
6057             }
6058         }
6059     }
6060     // </editor-fold>
6061 
6062     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6063         new TreeScanner() {
6064             Symbol packge = pkg;
6065             @Override
6066             public void visitIdent(JCIdent that) {
6067                 that.sym = packge;
6068             }
6069 
6070             @Override
6071             public void visitSelect(JCFieldAccess that) {
6072                 that.sym = packge;
6073                 packge = packge.owner;
6074                 super.visitSelect(that);
6075             }
6076         }.scan(pid);
6077     }
6078 
6079 }
--- EOF ---