1 /*
   2  * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.tools.javac.comp;
  27 
  28 import java.util.*;
  29 import java.util.function.BiConsumer;
  30 import java.util.function.Consumer;
  31 import java.util.function.Function;
  32 import java.util.stream.Stream;
  33 
  34 import javax.lang.model.element.ElementKind;
  35 import javax.tools.JavaFileObject;
  36 
  37 import com.sun.source.tree.CaseTree;
  38 import com.sun.source.tree.IdentifierTree;
  39 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
  40 import com.sun.source.tree.MemberSelectTree;
  41 import com.sun.source.tree.TreeVisitor;
  42 import com.sun.source.util.SimpleTreeVisitor;
  43 import com.sun.tools.javac.code.*;
  44 import com.sun.tools.javac.code.Lint.LintCategory;
  45 import com.sun.tools.javac.code.LintMapper;
  46 import com.sun.tools.javac.code.Scope.WriteableScope;
  47 import com.sun.tools.javac.code.Source.Feature;
  48 import com.sun.tools.javac.code.Symbol.*;
  49 import com.sun.tools.javac.code.Type.*;
  50 import com.sun.tools.javac.code.Types.FunctionDescriptorLookupError;
  51 import com.sun.tools.javac.comp.ArgumentAttr.LocalCacheContext;
  52 import com.sun.tools.javac.comp.Check.CheckContext;
  53 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
  54 import com.sun.tools.javac.comp.MatchBindingsComputer.MatchBindings;
  55 import com.sun.tools.javac.jvm.*;
  56 
  57 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
  58 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
  59 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
  60 
  61 import com.sun.tools.javac.resources.CompilerProperties.Errors;
  62 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  63 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings;
  64 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
  65 import com.sun.tools.javac.tree.*;
  66 import com.sun.tools.javac.tree.JCTree.*;
  67 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
  68 import com.sun.tools.javac.util.*;
  69 import com.sun.tools.javac.util.DefinedBy.Api;
  70 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  71 import com.sun.tools.javac.util.JCDiagnostic.Error;
  72 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
  73 import com.sun.tools.javac.util.JCDiagnostic.Warning;
  74 import com.sun.tools.javac.util.List;
  75 
  76 import static com.sun.tools.javac.code.Flags.*;
  77 import static com.sun.tools.javac.code.Flags.ANNOTATION;
  78 import static com.sun.tools.javac.code.Flags.BLOCK;
  79 import static com.sun.tools.javac.code.Kinds.*;
  80 import static com.sun.tools.javac.code.Kinds.Kind.*;
  81 import static com.sun.tools.javac.code.TypeTag.*;
  82 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
  83 import static com.sun.tools.javac.tree.JCTree.Tag.*;
  84 
  85 /** This is the main context-dependent analysis phase in GJC. It
  86  *  encompasses name resolution, type checking and constant folding as
  87  *  subtasks. Some subtasks involve auxiliary classes.
  88  *  @see Check
  89  *  @see Resolve
  90  *  @see ConstFold
  91  *  @see Infer
  92  *
  93  *  <p><b>This is NOT part of any supported API.
  94  *  If you write code that depends on this, you do so at your own risk.
  95  *  This code and its internal interfaces are subject to change or
  96  *  deletion without notice.</b>
  97  */
  98 public class Attr extends JCTree.Visitor {
  99     protected static final Context.Key<Attr> attrKey = new Context.Key<>();
 100 
 101     final Names names;
 102     final Log log;
 103     final LintMapper lintMapper;
 104     final Symtab syms;
 105     final Resolve rs;
 106     final Operators operators;
 107     final Infer infer;
 108     final Analyzer analyzer;
 109     final DeferredAttr deferredAttr;
 110     final Check chk;
 111     final Flow flow;
 112     final MemberEnter memberEnter;
 113     final TypeEnter typeEnter;
 114     final TreeMaker make;
 115     final ConstFold cfolder;
 116     final Enter enter;
 117     final Target target;
 118     final Types types;
 119     final Preview preview;
 120     final JCDiagnostic.Factory diags;
 121     final TypeAnnotations typeAnnotations;
 122     final TypeEnvs typeEnvs;
 123     final Dependencies dependencies;
 124     final Annotate annotate;
 125     final ArgumentAttr argumentAttr;
 126     final MatchBindingsComputer matchBindingsComputer;
 127     final AttrRecover attrRecover;
 128     final boolean captureMRefReturnType;
 129 
 130     public static Attr instance(Context context) {
 131         Attr instance = context.get(attrKey);
 132         if (instance == null)
 133             instance = new Attr(context);
 134         return instance;
 135     }
 136 
 137     @SuppressWarnings("this-escape")
 138     protected Attr(Context context) {
 139         context.put(attrKey, this);
 140 
 141         names = Names.instance(context);
 142         log = Log.instance(context);
 143         lintMapper = LintMapper.instance(context);
 144         syms = Symtab.instance(context);
 145         rs = Resolve.instance(context);
 146         operators = Operators.instance(context);
 147         chk = Check.instance(context);
 148         flow = Flow.instance(context);
 149         memberEnter = MemberEnter.instance(context);
 150         typeEnter = TypeEnter.instance(context);
 151         make = TreeMaker.instance(context);
 152         enter = Enter.instance(context);
 153         infer = Infer.instance(context);
 154         analyzer = Analyzer.instance(context);
 155         deferredAttr = DeferredAttr.instance(context);
 156         cfolder = ConstFold.instance(context);
 157         target = Target.instance(context);
 158         types = Types.instance(context);
 159         preview = Preview.instance(context);
 160         diags = JCDiagnostic.Factory.instance(context);
 161         annotate = Annotate.instance(context);
 162         typeAnnotations = TypeAnnotations.instance(context);
 163         typeEnvs = TypeEnvs.instance(context);
 164         dependencies = Dependencies.instance(context);
 165         argumentAttr = ArgumentAttr.instance(context);
 166         matchBindingsComputer = MatchBindingsComputer.instance(context);
 167         attrRecover = AttrRecover.instance(context);
 168 
 169         Options options = Options.instance(context);
 170 
 171         Source source = Source.instance(context);
 172         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 173         allowRecords = Feature.RECORDS.allowedInSource(source);
 174         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 175                              Feature.PATTERN_SWITCH.allowedInSource(source);
 176         allowUnconditionalPatternsInstanceOf =
 177                              Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 178         sourceName = source.name;
 179         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 180         captureMRefReturnType = Source.Feature.CAPTURE_MREF_RETURN_TYPE.allowedInSource(source);
 181 
 182         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 183         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 184         unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
 185         methodAttrInfo = new MethodAttrInfo();
 186         unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
 187         unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
 188         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
 189         initBlockType = new MethodType(List.nil(), syms.voidType, List.nil(), syms.methodClass);
 190     }
 191 
 192     /** Switch: reifiable types in instanceof enabled?
 193      */
 194     boolean allowReifiableTypesInInstanceof;
 195 
 196     /** Are records allowed
 197      */
 198     private final boolean allowRecords;
 199 
 200     /** Are patterns in switch allowed
 201      */
 202     private final boolean allowPatternSwitch;
 203 
 204     /** Are unconditional patterns in instanceof allowed
 205      */
 206     private final boolean allowUnconditionalPatternsInstanceOf;
 207 
 208     /**
 209      * Switch: warn about use of variable before declaration?
 210      * RFE: 6425594
 211      */
 212     boolean useBeforeDeclarationWarning;
 213 
 214     /**
 215      * Switch: name of source level; used for error reporting.
 216      */
 217     String sourceName;
 218 
 219     /** Check kind and type of given tree against protokind and prototype.
 220      *  If check succeeds, store type in tree and return it.
 221      *  If check fails, store errType in tree and return it.
 222      *  No checks are performed if the prototype is a method type.
 223      *  It is not necessary in this case since we know that kind and type
 224      *  are correct.
 225      *
 226      *  @param tree     The tree whose kind and type is checked
 227      *  @param found    The computed type of the tree
 228      *  @param ownkind  The computed kind of the tree
 229      *  @param resultInfo  The expected result of the tree
 230      */
 231     Type check(final JCTree tree,
 232                final Type found,
 233                final KindSelector ownkind,
 234                final ResultInfo resultInfo) {
 235         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 236         Type owntype;
 237         boolean shouldCheck = !found.hasTag(ERROR) &&
 238                 !resultInfo.pt.hasTag(METHOD) &&
 239                 !resultInfo.pt.hasTag(FORALL);
 240         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 241             log.error(tree.pos(),
 242                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 243                                             ownkind.kindNames()));
 244             owntype = types.createErrorType(found);
 245         } else if (inferenceContext.free(found)) {
 246             //delay the check if there are inference variables in the found type
 247             //this means we are dealing with a partially inferred poly expression
 248             owntype = shouldCheck ? resultInfo.pt : found;
 249             if (resultInfo.checkMode.installPostInferenceHook()) {
 250                 inferenceContext.addFreeTypeListener(List.of(found),
 251                         instantiatedContext -> {
 252                             ResultInfo pendingResult =
 253                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 254                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 255                         });
 256             }
 257         } else {
 258             owntype = shouldCheck ?
 259             resultInfo.check(tree, found) :
 260             found;
 261         }
 262         if (resultInfo.checkMode.updateTreeType()) {
 263             tree.type = owntype;
 264         }
 265         return owntype;
 266     }
 267 
 268     /** Is given blank final variable assignable, i.e. in a scope where it
 269      *  may be assigned to even though it is final?
 270      *  @param v      The blank final variable.
 271      *  @param env    The current environment.
 272      */
 273     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 274         Symbol owner = env.info.scope.owner;
 275            // owner refers to the innermost variable, method or
 276            // initializer block declaration at this point.
 277         boolean isAssignable =
 278             v.owner == owner
 279             ||
 280             ((owner.name == names.init ||    // i.e. we are in a constructor
 281               owner.kind == VAR ||           // i.e. we are in a variable initializer
 282               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 283              &&
 284              v.owner == owner.owner
 285              &&
 286              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 287         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 288         return isAssignable & !insideCompactConstructor;
 289     }
 290 
 291     /** Check that variable can be assigned to.
 292      *  @param pos    The current source code position.
 293      *  @param v      The assigned variable
 294      *  @param base   If the variable is referred to in a Select, the part
 295      *                to the left of the `.', null otherwise.
 296      *  @param env    The current environment.
 297      */
 298     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 299         if (v.name == names._this) {
 300             log.error(pos, Errors.CantAssignValToThis);
 301             return;
 302         }
 303         if ((v.flags() & FINAL) != 0 &&
 304             ((v.flags() & HASINIT) != 0
 305              ||
 306              !((base == null ||
 307                TreeInfo.isThisQualifier(base)) &&
 308                isAssignableAsBlankFinal(v, env)))) {
 309             if (v.isResourceVariable()) { //TWR resource
 310                 log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
 311             } else {
 312                 log.error(pos, Errors.CantAssignValToVar(Flags.toSource(v.flags() & (STATIC | FINAL)), v));
 313             }
 314             return;
 315         }
 316 
 317         // Check instance field assignments that appear in constructor prologues
 318         if (rs.isEarlyReference(env, base, v)) {
 319 
 320             // Field may not be inherited from a superclass
 321             if (v.owner != env.enclClass.sym) {
 322                 log.error(pos, Errors.CantRefBeforeCtorCalled(v));
 323                 return;
 324             }
 325 
 326             // Field may not have an initializer
 327             if ((v.flags() & HASINIT) != 0) {
 328                 log.error(pos, Errors.CantAssignInitializedBeforeCtorCalled(v));
 329                 return;
 330             }
 331         }
 332     }
 333 
 334     /** Does tree represent a static reference to an identifier?
 335      *  It is assumed that tree is either a SELECT or an IDENT.
 336      *  We have to weed out selects from non-type names here.
 337      *  @param tree    The candidate tree.
 338      */
 339     boolean isStaticReference(JCTree tree) {
 340         if (tree.hasTag(SELECT)) {
 341             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 342             if (lsym == null || lsym.kind != TYP) {
 343                 return false;
 344             }
 345         }
 346         return true;
 347     }
 348 
 349     /** Is this symbol a type?
 350      */
 351     static boolean isType(Symbol sym) {
 352         return sym != null && sym.kind == TYP;
 353     }
 354 
 355     /** Attribute a parsed identifier.
 356      * @param tree Parsed identifier name
 357      * @param topLevel The toplevel to use
 358      */
 359     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 360         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 361         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 362                                            syms.errSymbol.name,
 363                                            null, null, null, null);
 364         localEnv.enclClass.sym = syms.errSymbol;
 365         return attribIdent(tree, localEnv);
 366     }
 367 
 368     /** Attribute a parsed identifier.
 369      * @param tree Parsed identifier name
 370      * @param env The env to use
 371      */
 372     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 373         return tree.accept(identAttributer, env);
 374     }
 375     // where
 376         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 377         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 378             @Override @DefinedBy(Api.COMPILER_TREE)
 379             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 380                 Symbol site = visit(node.getExpression(), env);
 381                 if (site == null || site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 382                     return site;
 383                 Name name = (Name)node.getIdentifier();
 384                 if (site.kind == PCK) {
 385                     env.toplevel.packge = (PackageSymbol)site;
 386                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 387                             KindSelector.TYP_PCK);
 388                 } else {
 389                     env.enclClass.sym = (ClassSymbol)site;
 390                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 391                 }
 392             }
 393 
 394             @Override @DefinedBy(Api.COMPILER_TREE)
 395             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 396                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 397             }
 398         }
 399 
 400     public Type coerce(Type etype, Type ttype) {
 401         return cfolder.coerce(etype, ttype);
 402     }
 403 
 404     public Type attribType(JCTree node, TypeSymbol sym) {
 405         Env<AttrContext> env = typeEnvs.get(sym);
 406         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 407         return attribTree(node, localEnv, unknownTypeInfo);
 408     }
 409 
 410     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 411         // Attribute qualifying package or class.
 412         JCFieldAccess s = tree.qualid;
 413         return attribTree(s.selected, env,
 414                           new ResultInfo(tree.staticImport ?
 415                                          KindSelector.TYP : KindSelector.TYP_PCK,
 416                        Type.noType));
 417     }
 418 
 419     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 420         return attribToTree(expr, env, tree, unknownExprInfo);
 421     }
 422 
 423     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 424         return attribToTree(stmt, env, tree, statInfo);
 425     }
 426 
 427     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 428         breakTree = tree;
 429         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 430         try {
 431             deferredAttr.attribSpeculative(root, env, resultInfo,
 432                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 433                     argumentAttr.withLocalCacheContext());
 434             attrRecover.doRecovery();
 435         } catch (BreakAttr b) {
 436             return b.env;
 437         } catch (AssertionError ae) {
 438             if (ae.getCause() instanceof BreakAttr breakAttr) {
 439                 return breakAttr.env;
 440             } else {
 441                 throw ae;
 442             }
 443         } finally {
 444             breakTree = null;
 445             log.useSource(prev);
 446         }
 447         return env;
 448     }
 449 
 450     public <R> R runWithAttributedMethod(Env<AttrContext> env, JCMethodDecl tree, Function<JCBlock, R> attributedAction) {
 451         JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 452         try {
 453             annotate.queueScanTreeAndTypeAnnotate(tree.body, env, tree.sym);
 454             annotate.flush();
 455             JCBlock dupTree = (JCBlock)deferredAttr.attribSpeculative(tree.body, env, statInfo,
 456                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 457                     argumentAttr.withLocalCacheContext());
 458             return attributedAction.apply(dupTree);
 459         } finally {
 460             attrRecover.doRecovery();
 461             log.useSource(prevSource);
 462         }
 463     }
 464 
 465     private JCTree breakTree = null;
 466 
 467     private static class BreakAttr extends RuntimeException {
 468         static final long serialVersionUID = -6924771130405446405L;
 469         private transient Env<AttrContext> env;
 470         private BreakAttr(Env<AttrContext> env) {
 471             this.env = env;
 472         }
 473     }
 474 
 475     /**
 476      * Mode controlling behavior of Attr.Check
 477      */
 478     enum CheckMode {
 479 
 480         NORMAL,
 481 
 482         /**
 483          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 484          * that the captured var cache in {@code InferenceContext} will be used in read-only
 485          * mode when performing inference checks.
 486          */
 487         NO_TREE_UPDATE {
 488             @Override
 489             public boolean updateTreeType() {
 490                 return false;
 491             }
 492         },
 493         /**
 494          * Mode signalling that caller will manage free types in tree decorations.
 495          */
 496         NO_INFERENCE_HOOK {
 497             @Override
 498             public boolean installPostInferenceHook() {
 499                 return false;
 500             }
 501         };
 502 
 503         public boolean updateTreeType() {
 504             return true;
 505         }
 506         public boolean installPostInferenceHook() {
 507             return true;
 508         }
 509     }
 510 
 511 
 512     class ResultInfo {
 513         final KindSelector pkind;
 514         final Type pt;
 515         final CheckContext checkContext;
 516         final CheckMode checkMode;
 517 
 518         ResultInfo(KindSelector pkind, Type pt) {
 519             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 520         }
 521 
 522         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 523             this(pkind, pt, chk.basicHandler, checkMode);
 524         }
 525 
 526         protected ResultInfo(KindSelector pkind,
 527                              Type pt, CheckContext checkContext) {
 528             this(pkind, pt, checkContext, CheckMode.NORMAL);
 529         }
 530 
 531         protected ResultInfo(KindSelector pkind,
 532                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 533             this.pkind = pkind;
 534             this.pt = pt;
 535             this.checkContext = checkContext;
 536             this.checkMode = checkMode;
 537         }
 538 
 539         /**
 540          * Should {@link Attr#attribTree} use the {@code ArgumentAttr} visitor instead of this one?
 541          * @param tree The tree to be type-checked.
 542          * @return true if {@code ArgumentAttr} should be used.
 543          */
 544         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 545 
 546         protected Type check(final DiagnosticPosition pos, final Type found) {
 547             return chk.checkType(pos, found, pt, checkContext);
 548         }
 549 
 550         protected ResultInfo dup(Type newPt) {
 551             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 552         }
 553 
 554         protected ResultInfo dup(CheckContext newContext) {
 555             return new ResultInfo(pkind, pt, newContext, checkMode);
 556         }
 557 
 558         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 559             return new ResultInfo(pkind, newPt, newContext, checkMode);
 560         }
 561 
 562         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 563             return new ResultInfo(pkind, newPt, newContext, newMode);
 564         }
 565 
 566         protected ResultInfo dup(CheckMode newMode) {
 567             return new ResultInfo(pkind, pt, checkContext, newMode);
 568         }
 569 
 570         @Override
 571         public String toString() {
 572             if (pt != null) {
 573                 return pt.toString();
 574             } else {
 575                 return "";
 576             }
 577         }
 578     }
 579 
 580     class MethodAttrInfo extends ResultInfo {
 581         public MethodAttrInfo() {
 582             this(chk.basicHandler);
 583         }
 584 
 585         public MethodAttrInfo(CheckContext checkContext) {
 586             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 587         }
 588 
 589         @Override
 590         protected boolean needsArgumentAttr(JCTree tree) {
 591             return true;
 592         }
 593 
 594         protected ResultInfo dup(Type newPt) {
 595             throw new IllegalStateException();
 596         }
 597 
 598         protected ResultInfo dup(CheckContext newContext) {
 599             return new MethodAttrInfo(newContext);
 600         }
 601 
 602         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 603             throw new IllegalStateException();
 604         }
 605 
 606         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 607             throw new IllegalStateException();
 608         }
 609 
 610         protected ResultInfo dup(CheckMode newMode) {
 611             throw new IllegalStateException();
 612         }
 613     }
 614 
 615     class RecoveryInfo extends ResultInfo {
 616 
 617         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 618             this(deferredAttrContext, Type.recoveryType);
 619         }
 620 
 621         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 622             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 623                 @Override
 624                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 625                     return deferredAttrContext;
 626                 }
 627                 @Override
 628                 public boolean compatible(Type found, Type req, Warner warn) {
 629                     return true;
 630                 }
 631                 @Override
 632                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 633                     boolean needsReport = pt == Type.recoveryType ||
 634                             (details.getDiagnosticPosition() != null &&
 635                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 636                     if (needsReport) {
 637                         chk.basicHandler.report(pos, details);
 638                     }
 639                 }
 640             });
 641         }
 642     }
 643 
 644     final ResultInfo statInfo;
 645     final ResultInfo varAssignmentInfo;
 646     final ResultInfo methodAttrInfo;
 647     final ResultInfo unknownExprInfo;
 648     final ResultInfo unknownTypeInfo;
 649     final ResultInfo unknownTypeExprInfo;
 650     final ResultInfo recoveryInfo;
 651     final MethodType initBlockType;
 652 
 653     Type pt() {
 654         return resultInfo.pt;
 655     }
 656 
 657     KindSelector pkind() {
 658         return resultInfo.pkind;
 659     }
 660 
 661 /* ************************************************************************
 662  * Visitor methods
 663  *************************************************************************/
 664 
 665     /** Visitor argument: the current environment.
 666      */
 667     Env<AttrContext> env;
 668 
 669     /** Visitor argument: the currently expected attribution result.
 670      */
 671     ResultInfo resultInfo;
 672 
 673     /** Visitor result: the computed type.
 674      */
 675     Type result;
 676 
 677     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 678 
 679     /** Visitor method: attribute a tree, catching any completion failure
 680      *  exceptions. Return the tree's type.
 681      *
 682      *  @param tree    The tree to be visited.
 683      *  @param env     The environment visitor argument.
 684      *  @param resultInfo   The result info visitor argument.
 685      */
 686     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 687         Env<AttrContext> prevEnv = this.env;
 688         ResultInfo prevResult = this.resultInfo;
 689         try {
 690             this.env = env;
 691             this.resultInfo = resultInfo;
 692             if (resultInfo.needsArgumentAttr(tree)) {
 693                 result = argumentAttr.attribArg(tree, env);
 694             } else {
 695                 tree.accept(this);
 696             }
 697             matchBindings = matchBindingsComputer.finishBindings(tree,
 698                                                                  matchBindings);
 699             if (tree == breakTree &&
 700                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 701                 breakTreeFound(copyEnv(env));
 702             }
 703             return result;
 704         } catch (CompletionFailure ex) {
 705             tree.type = syms.errType;
 706             return chk.completionError(tree.pos(), ex);
 707         } finally {
 708             this.env = prevEnv;
 709             this.resultInfo = prevResult;
 710         }
 711     }
 712 
 713     protected void breakTreeFound(Env<AttrContext> env) {
 714         throw new BreakAttr(env);
 715     }
 716 
 717     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 718         Env<AttrContext> newEnv =
 719                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 720         if (newEnv.outer != null) {
 721             newEnv.outer = copyEnv(newEnv.outer);
 722         }
 723         return newEnv;
 724     }
 725 
 726     WriteableScope copyScope(WriteableScope sc) {
 727         WriteableScope newScope = WriteableScope.create(sc.owner);
 728         List<Symbol> elemsList = List.nil();
 729         for (Symbol sym : sc.getSymbols()) {
 730             elemsList = elemsList.prepend(sym);
 731         }
 732         for (Symbol s : elemsList) {
 733             newScope.enter(s);
 734         }
 735         return newScope;
 736     }
 737 
 738     /** Derived visitor method: attribute an expression tree.
 739      */
 740     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 741         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 742     }
 743 
 744     /** Derived visitor method: attribute an expression tree with
 745      *  no constraints on the computed type.
 746      */
 747     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 748         return attribTree(tree, env, unknownExprInfo);
 749     }
 750 
 751     /** Derived visitor method: attribute a type tree.
 752      */
 753     public Type attribType(JCTree tree, Env<AttrContext> env) {
 754         Type result = attribType(tree, env, Type.noType);
 755         return result;
 756     }
 757 
 758     /** Derived visitor method: attribute a type tree.
 759      */
 760     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 761         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 762         return result;
 763     }
 764 
 765     /** Derived visitor method: attribute a statement or definition tree.
 766      */
 767     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 768         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 769         Type result = attribTree(tree, env, statInfo);
 770         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 771         attrRecover.doRecovery();
 772         return result;
 773     }
 774 
 775     /** Attribute a list of expressions, returning a list of types.
 776      */
 777     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 778         ListBuffer<Type> ts = new ListBuffer<>();
 779         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 780             ts.append(attribExpr(l.head, env, pt));
 781         return ts.toList();
 782     }
 783 
 784     /** Attribute a list of statements, returning nothing.
 785      */
 786     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 787         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 788             attribStat(l.head, env);
 789     }
 790 
 791     /** Attribute the arguments in a method call, returning the method kind.
 792      */
 793     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 794         KindSelector kind = initialKind;
 795         for (JCExpression arg : trees) {
 796             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 797             if (argtype.hasTag(DEFERRED)) {
 798                 kind = KindSelector.of(KindSelector.POLY, kind);
 799             }
 800             argtypes.append(argtype);
 801         }
 802         return kind;
 803     }
 804 
 805     /** Attribute a type argument list, returning a list of types.
 806      *  Caller is responsible for calling checkRefTypes.
 807      */
 808     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 809         ListBuffer<Type> argtypes = new ListBuffer<>();
 810         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 811             argtypes.append(attribType(l.head, env));
 812         return argtypes.toList();
 813     }
 814 
 815     /** Attribute a type argument list, returning a list of types.
 816      *  Check that all the types are references.
 817      */
 818     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 819         List<Type> types = attribAnyTypes(trees, env);
 820         return chk.checkRefTypes(trees, types);
 821     }
 822 
 823     /**
 824      * Attribute type variables (of generic classes or methods).
 825      * Compound types are attributed later in attribBounds.
 826      * @param typarams the type variables to enter
 827      * @param env      the current environment
 828      */
 829     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 830         for (JCTypeParameter tvar : typarams) {
 831             TypeVar a = (TypeVar)tvar.type;
 832             a.tsym.flags_field |= UNATTRIBUTED;
 833             a.setUpperBound(Type.noType);
 834             if (!tvar.bounds.isEmpty()) {
 835                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 836                 for (JCExpression bound : tvar.bounds.tail)
 837                     bounds = bounds.prepend(attribType(bound, env));
 838                 types.setBounds(a, bounds.reverse());
 839             } else {
 840                 // if no bounds are given, assume a single bound of
 841                 // java.lang.Object.
 842                 types.setBounds(a, List.of(syms.objectType));
 843             }
 844             a.tsym.flags_field &= ~UNATTRIBUTED;
 845         }
 846         if (checkCyclic) {
 847             for (JCTypeParameter tvar : typarams) {
 848                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 849             }
 850         }
 851     }
 852 
 853     /**
 854      * Attribute the type references in a list of annotations.
 855      */
 856     void attribAnnotationTypes(List<JCAnnotation> annotations,
 857                                Env<AttrContext> env) {
 858         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 859             JCAnnotation a = al.head;
 860             attribType(a.annotationType, env);
 861         }
 862     }
 863 
 864     /**
 865      * Attribute a "lazy constant value".
 866      *  @param env         The env for the const value
 867      *  @param variable    The initializer for the const value
 868      *  @param type        The expected type, or null
 869      *  @see VarSymbol#setLazyConstValue
 870      */
 871     public Object attribLazyConstantValue(Env<AttrContext> env,
 872                                       Env<AttrContext> enclosingEnv,
 873                                       JCVariableDecl variable,
 874                                       Type type) {
 875         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 876         try {
 877             doQueueScanTreeAndTypeAnnotateForVarInit(variable, enclosingEnv);
 878             Type itype = attribExpr(variable.init, env, type);
 879             if (variable.isImplicitlyTyped()) {
 880                 //fixup local variable type
 881                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 882             }
 883             if (itype.constValue() != null) {
 884                 return coerce(itype, type).constValue();
 885             } else {
 886                 return null;
 887             }
 888         } finally {
 889             log.useSource(prevSource);
 890         }
 891     }
 892 
 893     /** Attribute type reference in an `extends', `implements', or 'permits' clause.
 894      *  Supertypes of anonymous inner classes are usually already attributed.
 895      *
 896      *  @param tree              The tree making up the type reference.
 897      *  @param env               The environment current at the reference.
 898      *  @param classExpected     true if only a class is expected here.
 899      *  @param interfaceExpected true if only an interface is expected here.
 900      */
 901     Type attribBase(JCTree tree,
 902                     Env<AttrContext> env,
 903                     boolean classExpected,
 904                     boolean interfaceExpected,
 905                     boolean checkExtensible) {
 906         Type t = tree.type != null ?
 907             tree.type :
 908             attribType(tree, env);
 909         try {
 910             return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 911         } catch (CompletionFailure ex) {
 912             chk.completionError(tree.pos(), ex);
 913             return t;
 914         }
 915     }
 916     Type checkBase(Type t,
 917                    JCTree tree,
 918                    Env<AttrContext> env,
 919                    boolean classExpected,
 920                    boolean interfaceExpected,
 921                    boolean checkExtensible) {
 922         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 923                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 924         if (t.tsym.isAnonymous()) {
 925             log.error(pos, Errors.CantInheritFromAnon);
 926             return types.createErrorType(t);
 927         }
 928         if (t.isErroneous())
 929             return t;
 930         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 931             // check that type variable is already visible
 932             if (t.getUpperBound() == null) {
 933                 log.error(pos, Errors.IllegalForwardRef);
 934                 return types.createErrorType(t);
 935             }
 936         } else {
 937             t = chk.checkClassType(pos, t, checkExtensible);
 938         }
 939         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 940             log.error(pos, Errors.IntfExpectedHere);
 941             // return errType is necessary since otherwise there might
 942             // be undetected cycles which cause attribution to loop
 943             return types.createErrorType(t);
 944         } else if (checkExtensible &&
 945                    classExpected &&
 946                    (t.tsym.flags() & INTERFACE) != 0) {
 947             log.error(pos, Errors.NoIntfExpectedHere);
 948             return types.createErrorType(t);
 949         }
 950         if (checkExtensible &&
 951             ((t.tsym.flags() & FINAL) != 0)) {
 952             log.error(pos,
 953                       Errors.CantInheritFromFinal(t.tsym));
 954         }
 955         chk.checkNonCyclic(pos, t);
 956         return t;
 957     }
 958 
 959     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 960         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 961         id.type = env.info.scope.owner.enclClass().type;
 962         id.sym = env.info.scope.owner.enclClass();
 963         return id.type;
 964     }
 965 
 966     public void visitClassDef(JCClassDecl tree) {
 967         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 968                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 969                         argumentAttr.withLocalCacheContext() : null);
 970         boolean ctorProloguePrev = env.info.ctorPrologue;
 971         try {
 972             // Local and anonymous classes have not been entered yet, so we need to
 973             // do it now.
 974             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 975                 enter.classEnter(tree, env);
 976             } else {
 977                 // If this class declaration is part of a class level annotation,
 978                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 979                 // order to simplify later steps and allow for sensible error
 980                 // messages.
 981                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 982                     enter.classEnter(tree, env);
 983             }
 984 
 985             ClassSymbol c = tree.sym;
 986             if (c == null) {
 987                 // exit in case something drastic went wrong during enter.
 988                 result = null;
 989             } else {
 990                 // make sure class has been completed:
 991                 c.complete();
 992 
 993                 // If a class declaration appears in a constructor prologue,
 994                 // that means it's either a local class or an anonymous class.
 995                 // Either way, there is no immediately enclosing instance.
 996                 if (ctorProloguePrev) {
 997                     c.flags_field |= NOOUTERTHIS;
 998                 }
 999                 attribClass(tree.pos(), c);
1000                 result = tree.type = c.type;
1001             }
1002         } finally {
1003             localCacheContext.ifPresent(LocalCacheContext::leave);
1004             env.info.ctorPrologue = ctorProloguePrev;
1005         }
1006     }
1007 
1008     public void visitMethodDef(JCMethodDecl tree) {
1009         MethodSymbol m = tree.sym;
1010         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
1011 
1012         Lint lint = env.info.lint.augment(m);
1013         Lint prevLint = chk.setLint(lint);
1014         boolean ctorProloguePrev = env.info.ctorPrologue;
1015         Assert.check(!env.info.ctorPrologue);
1016         MethodSymbol prevMethod = chk.setMethod(m);
1017         try {
1018             chk.checkDeprecatedAnnotation(tree.pos(), m);
1019 
1020 
1021             // Create a new environment with local scope
1022             // for attributing the method.
1023             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
1024             localEnv.info.lint = lint;
1025 
1026             attribStats(tree.typarams, localEnv);
1027 
1028             // If we override any other methods, check that we do so properly.
1029             // JLS ???
1030             if (m.isStatic()) {
1031                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1032             } else {
1033                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1034             }
1035             chk.checkOverride(env, tree, m);
1036 
1037             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1038                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1039             }
1040 
1041             // Enter all type parameters into the local method scope.
1042             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1043                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1044 
1045             ClassSymbol owner = env.enclClass.sym;
1046             if ((owner.flags() & ANNOTATION) != 0 &&
1047                     (tree.params.nonEmpty() ||
1048                     tree.recvparam != null))
1049                 log.error(tree.params.nonEmpty() ?
1050                         tree.params.head.pos() :
1051                         tree.recvparam.pos(),
1052                         Errors.IntfAnnotationMembersCantHaveParams);
1053 
1054             // Attribute all value parameters.
1055             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1056                 attribStat(l.head, localEnv);
1057             }
1058 
1059             chk.checkVarargsMethodDecl(localEnv, tree);
1060 
1061             // Check that type parameters are well-formed.
1062             chk.validate(tree.typarams, localEnv);
1063 
1064             // Check that result type is well-formed.
1065             if (tree.restype != null && !tree.restype.type.hasTag(VOID)) {
1066                 chk.validate(tree.restype, localEnv);
1067             }
1068             chk.checkRequiresIdentity(tree, env.info.lint);
1069 
1070             // Check that receiver type is well-formed.
1071             if (tree.recvparam != null) {
1072                 // Use a new environment to check the receiver parameter.
1073                 // Otherwise I get "might not have been initialized" errors.
1074                 // Is there a better way?
1075                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1076                 attribType(tree.recvparam, newEnv);
1077                 chk.validate(tree.recvparam, newEnv);
1078             }
1079 
1080             // Is this method a constructor?
1081             boolean isConstructor = TreeInfo.isConstructor(tree);
1082 
1083             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1084                 // lets find if this method is an accessor
1085                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1086                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1087                 if (recordComponent.isPresent()) {
1088                     // the method is a user defined accessor lets check that everything is fine
1089                     if (!tree.sym.isPublic()) {
1090                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1091                     }
1092                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1093                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1094                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1095                     }
1096                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1097                         log.error(tree,
1098                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1099                     }
1100                     if (!tree.typarams.isEmpty()) {
1101                         log.error(tree,
1102                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1103                     }
1104                     if (tree.sym.isStatic()) {
1105                         log.error(tree,
1106                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1107                     }
1108                 }
1109 
1110                 if (isConstructor) {
1111                     // if this a constructor other than the canonical one
1112                     if ((tree.sym.flags_field & RECORD) == 0) {
1113                         if (!TreeInfo.hasConstructorCall(tree, names._this)) {
1114                             log.error(tree, Errors.NonCanonicalConstructorInvokeAnotherConstructor(env.enclClass.sym));
1115                         }
1116                     } else {
1117                         // but if it is the canonical:
1118 
1119                         /* if user generated, then it shouldn't:
1120                          *     - have an accessibility stricter than that of the record type
1121                          *     - explicitly invoke any other constructor
1122                          */
1123                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1124                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1125                                 log.error(tree,
1126                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1127                                             Errors.InvalidCanonicalConstructorInRecord(
1128                                                 Fragments.Canonical,
1129                                                 env.enclClass.sym.name,
1130                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1131                                             ) :
1132                                             Errors.InvalidCanonicalConstructorInRecord(
1133                                                     Fragments.Canonical,
1134                                                     env.enclClass.sym.name,
1135                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1136                                             )
1137                                 );
1138                             }
1139 
1140                             if (TreeInfo.hasAnyConstructorCall(tree)) {
1141                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1142                                         Fragments.Canonical, env.enclClass.sym.name,
1143                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1144                             }
1145                         }
1146 
1147                         // also we want to check that no type variables have been defined
1148                         if (!tree.typarams.isEmpty()) {
1149                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1150                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1151                         }
1152 
1153                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1154                          * record components
1155                          */
1156                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1157                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1158                         for (JCVariableDecl param: tree.params) {
1159                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1160                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1161                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1162                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1163                                         Fragments.Canonical, env.enclClass.sym.name,
1164                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1165                             }
1166                             recordComponents = recordComponents.tail;
1167                             recordFieldTypes = recordFieldTypes.tail;
1168                         }
1169                     }
1170                 }
1171             }
1172 
1173             // annotation method checks
1174             if ((owner.flags() & ANNOTATION) != 0) {
1175                 // annotation method cannot have throws clause
1176                 if (tree.thrown.nonEmpty()) {
1177                     log.error(tree.thrown.head.pos(),
1178                               Errors.ThrowsNotAllowedInIntfAnnotation);
1179                 }
1180                 // annotation method cannot declare type-parameters
1181                 if (tree.typarams.nonEmpty()) {
1182                     log.error(tree.typarams.head.pos(),
1183                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1184                 }
1185                 // validate annotation method's return type (could be an annotation type)
1186                 chk.validateAnnotationType(tree.restype);
1187                 // ensure that annotation method does not clash with members of Object/Annotation
1188                 chk.validateAnnotationMethod(tree.pos(), m);
1189             }
1190 
1191             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1192                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1193 
1194             if (tree.body == null) {
1195                 // Empty bodies are only allowed for
1196                 // abstract, native, or interface methods, or for methods
1197                 // in a retrofit signature class.
1198                 if (tree.defaultValue != null) {
1199                     if ((owner.flags() & ANNOTATION) == 0)
1200                         log.error(tree.pos(),
1201                                   Errors.DefaultAllowedInIntfAnnotationMember);
1202                 }
1203                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1204                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract(tree.sym, owner));
1205             } else {
1206                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1207                     if ((owner.flags() & INTERFACE) != 0) {
1208                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1209                     } else {
1210                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1211                     }
1212                 } else if ((tree.mods.flags & NATIVE) != 0) {
1213                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1214                 }
1215                 // Add an implicit super() call unless an explicit call to
1216                 // super(...) or this(...) is given
1217                 // or we are compiling class java.lang.Object.
1218                 if (isConstructor && owner.type != syms.objectType) {
1219                     if (!TreeInfo.hasAnyConstructorCall(tree)) {
1220                         JCStatement supCall = make.at(tree.body.pos).Exec(make.Apply(List.nil(),
1221                                 make.Ident(names._super), make.Idents(List.nil())));
1222                         tree.body.stats = tree.body.stats.prepend(supCall);
1223                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1224                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1225                             TreeInfo.hasConstructorCall(tree, names._super)) {
1226                         // enum constructors are not allowed to call super
1227                         // directly, so make sure there aren't any super calls
1228                         // in enum constructors, except in the compiler
1229                         // generated one.
1230                         log.error(tree.body.stats.head.pos(),
1231                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1232                     }
1233                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1234                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1235                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1236                         if (!initParamNames.equals(recordComponentNames)) {
1237                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1238                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1239                         }
1240                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1241                             log.error(tree,
1242                                     Errors.InvalidCanonicalConstructorInRecord(
1243                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1244                                             env.enclClass.sym.name,
1245                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1246                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1247                         }
1248                     }
1249                 }
1250 
1251                 // Attribute all type annotations in the body
1252                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m);
1253                 annotate.flush();
1254 
1255                 // Start of constructor prologue (if not in java.lang.Object constructor)
1256                 localEnv.info.ctorPrologue = isConstructor && owner.type != syms.objectType;
1257 
1258                 // Attribute method body.
1259                 attribStat(tree.body, localEnv);
1260             }
1261 
1262             localEnv.info.scope.leave();
1263             result = tree.type = m.type;
1264         } finally {
1265             chk.setLint(prevLint);
1266             chk.setMethod(prevMethod);
1267             env.info.ctorPrologue = ctorProloguePrev;
1268         }
1269     }
1270 
1271     public void visitVarDef(JCVariableDecl tree) {
1272         // Local variables have not been entered yet, so we need to do it now:
1273         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1274             if (tree.sym != null) {
1275                 // parameters have already been entered
1276                 env.info.scope.enter(tree.sym);
1277             } else {
1278                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
1279                     if (tree.init == null) {
1280                         //cannot use 'var' without initializer
1281                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1282                         tree.vartype = make.at(tree.pos()).Erroneous();
1283                     } else {
1284                         Fragment msg = canInferLocalVarType(tree);
1285                         if (msg != null) {
1286                             //cannot use 'var' with initializer which require an explicit target
1287                             //(e.g. lambda, method reference, array initializer).
1288                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1289                             tree.vartype = make.at(tree.pos()).Erroneous();
1290                         }
1291                     }
1292                 }
1293                 try {
1294                     annotate.blockAnnotations();
1295                     memberEnter.memberEnter(tree, env);
1296                 } finally {
1297                     annotate.unblockAnnotations();
1298                 }
1299             }
1300         } else {
1301             doQueueScanTreeAndTypeAnnotateForVarInit(tree, env);
1302         }
1303 
1304         VarSymbol v = tree.sym;
1305         Lint lint = env.info.lint.augment(v);
1306         Lint prevLint = chk.setLint(lint);
1307 
1308         // Check that the variable's declared type is well-formed.
1309         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1310                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1311                 (tree.sym.flags() & PARAMETER) != 0;
1312         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1313 
1314         try {
1315             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1316             chk.checkDeprecatedAnnotation(tree.pos(), v);
1317 
1318             if (tree.init != null) {
1319                 if ((v.flags_field & FINAL) == 0 ||
1320                     !memberEnter.needsLazyConstValue(tree.init)) {
1321                     // Not a compile-time constant
1322                     // Attribute initializer in a new environment
1323                     // with the declared variable as owner.
1324                     // Check that initializer conforms to variable's declared type.
1325                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
1326                     initEnv.info.lint = lint;
1327                     // In order to catch self-references, we set the variable's
1328                     // declaration position to maximal possible value, effectively
1329                     // marking the variable as undefined.
1330                     initEnv.info.enclVar = v;
1331                     attribExpr(tree.init, initEnv, v.type);
1332                     if (tree.isImplicitlyTyped()) {
1333                         //fixup local variable type
1334                         v.type = chk.checkLocalVarType(tree, tree.init.type, tree.name);
1335                     }
1336                 }
1337                 if (tree.isImplicitlyTyped()) {
1338                     setSyntheticVariableType(tree, v.type);
1339                 }
1340             }
1341             result = tree.type = v.type;
1342             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
1343                 if (isNonArgsMethodInObject(v.name)) {
1344                     log.error(tree, Errors.IllegalRecordComponentName(v));
1345                 }
1346             }
1347             chk.checkRequiresIdentity(tree, env.info.lint);
1348         }
1349         finally {
1350             chk.setLint(prevLint);
1351         }
1352     }
1353 
1354     private void doQueueScanTreeAndTypeAnnotateForVarInit(JCVariableDecl tree, Env<AttrContext> env) {
1355         if (tree.init != null &&
1356             (tree.mods.flags & Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED) == 0 &&
1357             env.info.scope.owner.kind != MTH && env.info.scope.owner.kind != VAR) {
1358             tree.mods.flags |= Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED;
1359             // Field initializer expression need to be entered.
1360             annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym);
1361             annotate.flush();
1362         }
1363     }
1364 
1365     private boolean isNonArgsMethodInObject(Name name) {
1366         for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
1367             if (s.type.getParameterTypes().isEmpty()) {
1368                 return true;
1369             }
1370         }
1371         return false;
1372     }
1373 
1374     Fragment canInferLocalVarType(JCVariableDecl tree) {
1375         LocalInitScanner lis = new LocalInitScanner();
1376         lis.scan(tree.init);
1377         return lis.badInferenceMsg;
1378     }
1379 
1380     static class LocalInitScanner extends TreeScanner {
1381         Fragment badInferenceMsg = null;
1382         boolean needsTarget = true;
1383 
1384         @Override
1385         public void visitNewArray(JCNewArray tree) {
1386             if (tree.elemtype == null && needsTarget) {
1387                 badInferenceMsg = Fragments.LocalArrayMissingTarget;
1388             }
1389         }
1390 
1391         @Override
1392         public void visitLambda(JCLambda tree) {
1393             if (needsTarget) {
1394                 badInferenceMsg = Fragments.LocalLambdaMissingTarget;
1395             }
1396         }
1397 
1398         @Override
1399         public void visitTypeCast(JCTypeCast tree) {
1400             boolean prevNeedsTarget = needsTarget;
1401             try {
1402                 needsTarget = false;
1403                 super.visitTypeCast(tree);
1404             } finally {
1405                 needsTarget = prevNeedsTarget;
1406             }
1407         }
1408 
1409         @Override
1410         public void visitReference(JCMemberReference tree) {
1411             if (needsTarget) {
1412                 badInferenceMsg = Fragments.LocalMrefMissingTarget;
1413             }
1414         }
1415 
1416         @Override
1417         public void visitNewClass(JCNewClass tree) {
1418             boolean prevNeedsTarget = needsTarget;
1419             try {
1420                 needsTarget = false;
1421                 super.visitNewClass(tree);
1422             } finally {
1423                 needsTarget = prevNeedsTarget;
1424             }
1425         }
1426 
1427         @Override
1428         public void visitApply(JCMethodInvocation tree) {
1429             boolean prevNeedsTarget = needsTarget;
1430             try {
1431                 needsTarget = false;
1432                 super.visitApply(tree);
1433             } finally {
1434                 needsTarget = prevNeedsTarget;
1435             }
1436         }
1437     }
1438 
1439     public void visitSkip(JCSkip tree) {
1440         result = null;
1441     }
1442 
1443     public void visitBlock(JCBlock tree) {
1444         if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
1445             // Block is a static or instance initializer;
1446             // let the owner of the environment be a freshly
1447             // created BLOCK-method.
1448             Symbol fakeOwner =
1449                 new MethodSymbol(tree.flags | BLOCK |
1450                     env.info.scope.owner.flags() & STRICTFP, names.empty, initBlockType,
1451                     env.info.scope.owner);
1452             final Env<AttrContext> localEnv =
1453                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
1454 
1455             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
1456             // Attribute all type annotations in the block
1457             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner);
1458             annotate.flush();
1459             attribStats(tree.stats, localEnv);
1460 
1461             {
1462                 // Store init and clinit type annotations with the ClassSymbol
1463                 // to allow output in Gen.normalizeDefs.
1464                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1465                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1466                 if ((tree.flags & STATIC) != 0) {
1467                     cs.appendClassInitTypeAttributes(tas);
1468                 } else {
1469                     cs.appendInitTypeAttributes(tas);
1470                 }
1471             }
1472         } else {
1473             // Create a new local environment with a local scope.
1474             Env<AttrContext> localEnv =
1475                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1476             try {
1477                 attribStats(tree.stats, localEnv);
1478             } finally {
1479                 localEnv.info.scope.leave();
1480             }
1481         }
1482         result = null;
1483     }
1484 
1485     public void visitDoLoop(JCDoWhileLoop tree) {
1486         attribStat(tree.body, env.dup(tree));
1487         attribExpr(tree.cond, env, syms.booleanType);
1488         handleLoopConditionBindings(matchBindings, tree, tree.body);
1489         result = null;
1490     }
1491 
1492     public void visitWhileLoop(JCWhileLoop tree) {
1493         attribExpr(tree.cond, env, syms.booleanType);
1494         MatchBindings condBindings = matchBindings;
1495         // include condition's bindings when true in the body:
1496         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1497         try {
1498             attribStat(tree.body, whileEnv.dup(tree));
1499         } finally {
1500             whileEnv.info.scope.leave();
1501         }
1502         handleLoopConditionBindings(condBindings, tree, tree.body);
1503         result = null;
1504     }
1505 
1506     public void visitForLoop(JCForLoop tree) {
1507         Env<AttrContext> loopEnv =
1508             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1509         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1510         try {
1511             attribStats(tree.init, loopEnv);
1512             if (tree.cond != null) {
1513                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1514                 // include condition's bindings when true in the body and step:
1515                 condBindings = matchBindings;
1516             }
1517             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1518             try {
1519                 bodyEnv.tree = tree; // before, we were not in loop!
1520                 attribStats(tree.step, bodyEnv);
1521                 attribStat(tree.body, bodyEnv);
1522             } finally {
1523                 bodyEnv.info.scope.leave();
1524             }
1525             result = null;
1526         }
1527         finally {
1528             loopEnv.info.scope.leave();
1529         }
1530         handleLoopConditionBindings(condBindings, tree, tree.body);
1531     }
1532 
1533     /**
1534      * Include condition's bindings when false after the loop, if cannot get out of the loop
1535      */
1536     private void handleLoopConditionBindings(MatchBindings condBindings,
1537                                              JCStatement loop,
1538                                              JCStatement loopBody) {
1539         if (condBindings.bindingsWhenFalse.nonEmpty() &&
1540             !breaksTo(env, loop, loopBody)) {
1541             addBindings2Scope(loop, condBindings.bindingsWhenFalse);
1542         }
1543     }
1544 
1545     private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
1546         preFlow(body);
1547         return flow.breaksToTree(env, loop, body, make);
1548     }
1549 
1550     /**
1551      * Add given bindings to the current scope, unless there's a break to
1552      * an immediately enclosing labeled statement.
1553      */
1554     private void addBindings2Scope(JCStatement introducingStatement,
1555                                    List<BindingSymbol> bindings) {
1556         if (bindings.isEmpty()) {
1557             return ;
1558         }
1559 
1560         var searchEnv = env;
1561         while (searchEnv.tree instanceof JCLabeledStatement labeled &&
1562                labeled.body == introducingStatement) {
1563             if (breaksTo(env, labeled, labeled.body)) {
1564                 //breaking to an immediately enclosing labeled statement
1565                 return ;
1566             }
1567             searchEnv = searchEnv.next;
1568             introducingStatement = labeled;
1569         }
1570 
1571         //include condition's body when false after the while, if cannot get out of the loop
1572         bindings.forEach(env.info.scope::enter);
1573         bindings.forEach(BindingSymbol::preserveBinding);
1574     }
1575 
1576     public void visitForeachLoop(JCEnhancedForLoop tree) {
1577         Env<AttrContext> loopEnv =
1578             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1579         try {
1580             //the Formal Parameter of a for-each loop is not in the scope when
1581             //attributing the for-each expression; we mimic this by attributing
1582             //the for-each expression first (against original scope).
1583             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1584             chk.checkNonVoid(tree.pos(), exprType);
1585             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1586             if (elemtype == null) {
1587                 // or perhaps expr implements Iterable<T>?
1588                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1589                 if (base == null) {
1590                     log.error(tree.expr.pos(),
1591                               Errors.ForeachNotApplicableToType(exprType,
1592                                                                 Fragments.TypeReqArrayOrIterable));
1593                     elemtype = types.createErrorType(exprType);
1594                 } else {
1595                     List<Type> iterableParams = base.allparams();
1596                     elemtype = iterableParams.isEmpty()
1597                         ? syms.objectType
1598                         : types.wildUpperBound(iterableParams.head);
1599 
1600                     // Check the return type of the method iterator().
1601                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1602                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1603                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1604                     if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
1605                         log.error(tree.pos(),
1606                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1607                     }
1608                 }
1609             }
1610             if (tree.var.isImplicitlyTyped()) {
1611                 Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
1612                 setSyntheticVariableType(tree.var, inferredType);
1613             }
1614             attribStat(tree.var, loopEnv);
1615             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1616             loopEnv.tree = tree; // before, we were not in loop!
1617             attribStat(tree.body, loopEnv);
1618             result = null;
1619         }
1620         finally {
1621             loopEnv.info.scope.leave();
1622         }
1623     }
1624 
1625     public void visitLabelled(JCLabeledStatement tree) {
1626         // Check that label is not used in an enclosing statement
1627         Env<AttrContext> env1 = env;
1628         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1629             if (env1.tree.hasTag(LABELLED) &&
1630                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1631                 log.error(tree.pos(),
1632                           Errors.LabelAlreadyInUse(tree.label));
1633                 break;
1634             }
1635             env1 = env1.next;
1636         }
1637 
1638         attribStat(tree.body, env.dup(tree));
1639         result = null;
1640     }
1641 
1642     public void visitSwitch(JCSwitch tree) {
1643         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1644             attribStats(c.stats, caseEnv);
1645         });
1646         result = null;
1647     }
1648 
1649     public void visitSwitchExpression(JCSwitchExpression tree) {
1650         boolean wrongContext = false;
1651 
1652         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
1653                 PolyKind.STANDALONE : PolyKind.POLY;
1654 
1655         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
1656             //this means we are returning a poly conditional from void-compatible lambda expression
1657             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
1658             resultInfo = recoveryInfo;
1659             wrongContext = true;
1660         }
1661 
1662         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
1663                 unknownExprInfo :
1664                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
1665 
1666         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
1667         ListBuffer<Type> caseTypes = new ListBuffer<>();
1668 
1669         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1670             caseEnv.info.yieldResult = condInfo;
1671             attribStats(c.stats, caseEnv);
1672             new TreeScanner() {
1673                 @Override
1674                 public void visitYield(JCYield brk) {
1675                     if (brk.target == tree) {
1676                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
1677                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
1678                     }
1679                     super.visitYield(brk);
1680                 }
1681 
1682                 @Override public void visitClassDef(JCClassDecl tree) {}
1683                 @Override public void visitLambda(JCLambda tree) {}
1684             }.scan(c.stats);
1685         });
1686 
1687         if (tree.cases.isEmpty()) {
1688             log.error(tree.pos(),
1689                       Errors.SwitchExpressionEmpty);
1690         } else if (caseTypes.isEmpty()) {
1691             log.error(tree.pos(),
1692                       Errors.SwitchExpressionNoResultExpressions);
1693         }
1694 
1695         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
1696 
1697         result = tree.type = wrongContext? types.createErrorType(pt()) : check(tree, owntype, KindSelector.VAL, resultInfo);
1698     }
1699     //where:
1700         CheckContext switchExpressionContext(CheckContext checkContext) {
1701             return new Check.NestedCheckContext(checkContext) {
1702                 //this will use enclosing check context to check compatibility of
1703                 //subexpression against target type; if we are in a method check context,
1704                 //depending on whether boxing is allowed, we could have incompatibilities
1705                 @Override
1706                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1707                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
1708                 }
1709             };
1710         }
1711 
1712     private void handleSwitch(JCTree switchTree,
1713                               JCExpression selector,
1714                               List<JCCase> cases,
1715                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
1716         Type seltype = attribExpr(selector, env);
1717         Type seltypeUnboxed = types.unboxedTypeOrType(seltype);
1718 
1719         Env<AttrContext> switchEnv =
1720             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
1721 
1722         try {
1723             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
1724             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
1725             boolean booleanSwitch = types.isSameType(seltypeUnboxed, syms.booleanType);
1726             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
1727             boolean intSwitch = types.isAssignable(seltype, syms.intType);
1728             boolean patternSwitch;
1729             if (seltype.isPrimitive() && !intSwitch) {
1730                 preview.checkSourceLevel(selector.pos(), Feature.PRIMITIVE_PATTERNS);
1731                 patternSwitch = true;
1732             }
1733             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
1734                 !intSwitch) {
1735                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
1736                 patternSwitch = true;
1737             } else {
1738                 patternSwitch = cases.stream()
1739                                      .flatMap(c -> c.labels.stream())
1740                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
1741                                                     TreeInfo.isNullCaseLabel(l));
1742             }
1743 
1744             // Attribute all cases and
1745             // check that there are no duplicate case labels or default clauses.
1746             Set<Object> constants = new HashSet<>(); // The set of case constants.
1747             boolean hasDefault = false;           // Is there a default label?
1748             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
1749             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
1750             boolean hasNullPattern = false;       // Is there a null pattern?
1751             CaseTree.CaseKind caseKind = null;
1752             boolean wasError = false;
1753             JCCaseLabel unconditionalCaseLabel = null;
1754             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
1755                 JCCase c = l.head;
1756                 if (caseKind == null) {
1757                     caseKind = c.caseKind;
1758                 } else if (caseKind != c.caseKind && !wasError) {
1759                     log.error(c.pos(),
1760                               Errors.SwitchMixingCaseTypes);
1761                     wasError = true;
1762                 }
1763                 MatchBindings currentBindings = null;
1764                 MatchBindings guardBindings = null;
1765                 for (List<JCCaseLabel> labels = c.labels; labels.nonEmpty(); labels = labels.tail) {
1766                     JCCaseLabel label = labels.head;
1767                     if (label instanceof JCConstantCaseLabel constLabel) {
1768                         JCExpression expr = constLabel.expr;
1769                         if (TreeInfo.isNull(expr)) {
1770                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
1771                             if (hasNullPattern) {
1772                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1773                             }
1774                             hasNullPattern = true;
1775                             attribExpr(expr, switchEnv, seltype);
1776                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
1777                         } else if (enumSwitch) {
1778                             Symbol sym = enumConstant(expr, seltype);
1779                             if (sym == null) {
1780                                 if (allowPatternSwitch) {
1781                                     attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1782                                     Symbol enumSym = TreeInfo.symbol(expr);
1783                                     if (enumSym == null || !enumSym.isEnum() || enumSym.kind != VAR) {
1784                                         log.error(expr.pos(), Errors.EnumLabelMustBeEnumConstant);
1785                                     } else if (!constants.add(enumSym)) {
1786                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1787                                     }
1788                                 } else {
1789                                     log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
1790                                 }
1791                             } else if (!constants.add(sym)) {
1792                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1793                             }
1794                         } else if (errorEnumSwitch) {
1795                             //error recovery: the selector is erroneous, and all the case labels
1796                             //are identifiers. This could be an enum switch - don't report resolve
1797                             //error for the case label:
1798                             var prevResolveHelper = rs.basicLogResolveHelper;
1799                             try {
1800                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
1801                                 attribExpr(expr, switchEnv, seltype);
1802                             } finally {
1803                                 rs.basicLogResolveHelper = prevResolveHelper;
1804                             }
1805                         } else {
1806                             Type pattype = attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1807                             if (!pattype.hasTag(ERROR)) {
1808                                 if (pattype.constValue() == null) {
1809                                     Symbol s = TreeInfo.symbol(expr);
1810                                     if (s != null && s.kind == TYP) {
1811                                         log.error(expr.pos(),
1812                                                   Errors.PatternExpected);
1813                                     } else if (s == null || !s.isEnum()) {
1814                                         log.error(expr.pos(),
1815                                                   (stringSwitch ? Errors.StringConstReq
1816                                                                 : intSwitch ? Errors.ConstExprReq
1817                                                                             : Errors.PatternOrEnumReq));
1818                                     } else if (!constants.add(s)) {
1819                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1820                                     }
1821                                 }
1822                                 else {
1823                                     boolean isLongFloatDoubleOrBooleanConstant =
1824                                             pattype.getTag().isInSuperClassesOf(LONG) || pattype.getTag().equals(BOOLEAN);
1825                                     if (isLongFloatDoubleOrBooleanConstant) {
1826                                         preview.checkSourceLevel(label.pos(), Feature.PRIMITIVE_PATTERNS);
1827                                     }
1828                                     if (!stringSwitch && !intSwitch && !(isLongFloatDoubleOrBooleanConstant && types.isSameType(seltypeUnboxed, pattype))) {
1829                                         log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
1830                                     } else if (!constants.add(pattype.constValue())) {
1831                                         log.error(c.pos(), Errors.DuplicateCaseLabel);
1832                                     }
1833                                 }
1834                             }
1835                         }
1836                     } else if (label instanceof JCDefaultCaseLabel def) {
1837                         if (hasDefault) {
1838                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
1839                         } else if (hasUnconditionalPattern) {
1840                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
1841                         }  else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1842                             log.error(label.pos(), Errors.DefaultAndBothBooleanValues);
1843                         }
1844                         hasDefault = true;
1845                         matchBindings = MatchBindingsComputer.EMPTY;
1846                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
1847                         //pattern
1848                         JCPattern pat = patternlabel.pat;
1849                         attribExpr(pat, switchEnv, seltype);
1850                         Type primaryType = TreeInfo.primaryPatternType(pat);
1851 
1852                         if (primaryType.isPrimitive()) {
1853                             preview.checkSourceLevel(pat.pos(), Feature.PRIMITIVE_PATTERNS);
1854                         } else if (!primaryType.hasTag(TYPEVAR)) {
1855                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
1856                         }
1857                         checkCastablePattern(pat.pos(), seltype, primaryType);
1858                         Type patternType = types.erasure(primaryType);
1859                         JCExpression guard = c.guard;
1860                         if (guardBindings == null && guard != null) {
1861                             MatchBindings afterPattern = matchBindings;
1862                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
1863                             try {
1864                                 attribExpr(guard, bodyEnv, syms.booleanType);
1865                             } finally {
1866                                 bodyEnv.info.scope.leave();
1867                             }
1868 
1869                             guardBindings = matchBindings;
1870                             matchBindings = afterPattern;
1871 
1872                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
1873                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
1874                             }
1875                         }
1876                         boolean unguarded = TreeInfo.unguardedCase(c) && !pat.hasTag(RECORDPATTERN);
1877                         boolean unconditional =
1878                                 unguarded &&
1879                                 !patternType.isErroneous() &&
1880                                 types.isUnconditionallyExactTypeBased(seltype, patternType);
1881                         if (unconditional) {
1882                             if (hasUnconditionalPattern) {
1883                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
1884                             } else if (hasDefault) {
1885                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
1886                             } else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1887                                 log.error(pat.pos(), Errors.UnconditionalPatternAndBothBooleanValues);
1888                             }
1889                             hasUnconditionalPattern = true;
1890                             unconditionalCaseLabel = label;
1891                         }
1892                         lastPatternErroneous = patternType.isErroneous();
1893                     } else {
1894                         Assert.error();
1895                     }
1896                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
1897                 }
1898 
1899                 if (guardBindings != null) {
1900                     currentBindings = matchBindingsComputer.caseGuard(c, currentBindings, guardBindings);
1901                 }
1902 
1903                 Env<AttrContext> caseEnv =
1904                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
1905                 try {
1906                     attribCase.accept(c, caseEnv);
1907                 } finally {
1908                     caseEnv.info.scope.leave();
1909                 }
1910                 addVars(c.stats, switchEnv.info.scope);
1911 
1912                 preFlow(c);
1913                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
1914             }
1915             if (patternSwitch) {
1916                 chk.checkSwitchCaseStructure(cases);
1917                 chk.checkSwitchCaseLabelDominated(unconditionalCaseLabel, cases);
1918             }
1919             if (switchTree.hasTag(SWITCH)) {
1920                 ((JCSwitch) switchTree).hasUnconditionalPattern =
1921                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1922                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
1923             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
1924                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
1925                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1926                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
1927             } else {
1928                 Assert.error(switchTree.getTag().name());
1929             }
1930         } finally {
1931             switchEnv.info.scope.leave();
1932         }
1933     }
1934     // where
1935         private ResultInfo caseLabelResultInfo(Type seltype) {
1936             return new ResultInfo(KindSelector.VAL_TYP,
1937                                   !seltype.hasTag(ERROR) ? seltype
1938                                                          : Type.noType);
1939         }
1940         /** Add any variables defined in stats to the switch scope. */
1941         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
1942             for (;stats.nonEmpty(); stats = stats.tail) {
1943                 JCTree stat = stats.head;
1944                 if (stat.hasTag(VARDEF))
1945                     switchScope.enter(((JCVariableDecl) stat).sym);
1946             }
1947         }
1948     // where
1949     /** Return the selected enumeration constant symbol, or null. */
1950     private Symbol enumConstant(JCTree tree, Type enumType) {
1951         if (tree.hasTag(IDENT)) {
1952             JCIdent ident = (JCIdent)tree;
1953             Name name = ident.name;
1954             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
1955                 if (sym.kind == VAR) {
1956                     Symbol s = ident.sym = sym;
1957                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1958                     ident.type = s.type;
1959                     return ((s.flags_field & Flags.ENUM) == 0)
1960                         ? null : s;
1961                 }
1962             }
1963         }
1964         return null;
1965     }
1966 
1967     public void visitSynchronized(JCSynchronized tree) {
1968         chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
1969         if (tree.lock.type != null && tree.lock.type.isValueBased()) {
1970             log.warning(tree.pos(), LintWarnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
1971         }
1972         attribStat(tree.body, env);
1973         result = null;
1974     }
1975 
1976     public void visitTry(JCTry tree) {
1977         // Create a new local environment with a local
1978         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1979         try {
1980             boolean isTryWithResource = tree.resources.nonEmpty();
1981             // Create a nested environment for attributing the try block if needed
1982             Env<AttrContext> tryEnv = isTryWithResource ?
1983                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1984                 localEnv;
1985             try {
1986                 // Attribute resource declarations
1987                 for (JCTree resource : tree.resources) {
1988                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
1989                         @Override
1990                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
1991                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
1992                         }
1993                     };
1994                     ResultInfo twrResult =
1995                         new ResultInfo(KindSelector.VAR,
1996                                        syms.autoCloseableType,
1997                                        twrContext);
1998                     if (resource.hasTag(VARDEF)) {
1999                         attribStat(resource, tryEnv);
2000                         twrResult.check(resource, resource.type);
2001 
2002                         //check that resource type cannot throw InterruptedException
2003                         checkAutoCloseable(localEnv, resource, true);
2004 
2005                         VarSymbol var = ((JCVariableDecl) resource).sym;
2006 
2007                         var.flags_field |= Flags.FINAL;
2008                         var.setData(ElementKind.RESOURCE_VARIABLE);
2009                     } else {
2010                         attribTree(resource, tryEnv, twrResult);
2011                     }
2012                 }
2013                 // Attribute body
2014                 attribStat(tree.body, tryEnv);
2015             } finally {
2016                 if (isTryWithResource)
2017                     tryEnv.info.scope.leave();
2018             }
2019 
2020             // Attribute catch clauses
2021             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
2022                 JCCatch c = l.head;
2023                 Env<AttrContext> catchEnv =
2024                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
2025                 try {
2026                     Type ctype = attribStat(c.param, catchEnv);
2027                     if (TreeInfo.isMultiCatch(c)) {
2028                         //multi-catch parameter is implicitly marked as final
2029                         c.param.sym.flags_field |= FINAL | UNION;
2030                     }
2031                     if (c.param.sym.kind == VAR) {
2032                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
2033                     }
2034                     chk.checkType(c.param.vartype.pos(),
2035                                   chk.checkClassType(c.param.vartype.pos(), ctype),
2036                                   syms.throwableType);
2037                     attribStat(c.body, catchEnv);
2038                 } finally {
2039                     catchEnv.info.scope.leave();
2040                 }
2041             }
2042 
2043             // Attribute finalizer
2044             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
2045             result = null;
2046         }
2047         finally {
2048             localEnv.info.scope.leave();
2049         }
2050     }
2051 
2052     void checkAutoCloseable(Env<AttrContext> env, JCTree tree, boolean useSite) {
2053         DiagnosticPosition pos = tree.pos();
2054         Type resource = tree.type;
2055         if (!resource.isErroneous() &&
2056             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
2057             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
2058             Symbol close = syms.noSymbol;
2059             Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
2060             try {
2061                 close = rs.resolveQualifiedMethod(pos,
2062                         env,
2063                         types.skipTypeVars(resource, false),
2064                         names.close,
2065                         List.nil(),
2066                         List.nil());
2067             }
2068             finally {
2069                 log.popDiagnosticHandler(discardHandler);
2070             }
2071             if (close.kind == MTH &&
2072                     (useSite || close.owner != syms.autoCloseableType.tsym) &&
2073                     ((MethodSymbol)close).binaryOverrides(syms.autoCloseableClose, resource.tsym, types) &&
2074                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes())) {
2075                 if (!useSite && close.owner == resource.tsym) {
2076                     log.warning(TreeInfo.diagnosticPositionFor(close, tree),
2077                         LintWarnings.TryResourceCanThrowInterruptedExc(resource));
2078                 } else {
2079                     log.warning(pos, LintWarnings.TryResourceThrowsInterruptedExc(resource));
2080                 }
2081             }
2082         }
2083     }
2084 
2085     public void visitConditional(JCConditional tree) {
2086         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2087         MatchBindings condBindings = matchBindings;
2088 
2089         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2090                 isBooleanOrNumeric(env, tree)) ?
2091                 PolyKind.STANDALONE : PolyKind.POLY;
2092 
2093         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2094             //this means we are returning a poly conditional from void-compatible lambda expression
2095             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2096             result = tree.type = types.createErrorType(resultInfo.pt);
2097             return;
2098         }
2099 
2100         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2101                 unknownExprInfo :
2102                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2103 
2104 
2105         // x ? y : z
2106         // include x's bindings when true in y
2107         // include x's bindings when false in z
2108 
2109         Type truetype;
2110         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2111         try {
2112             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2113         } finally {
2114             trueEnv.info.scope.leave();
2115         }
2116 
2117         MatchBindings trueBindings = matchBindings;
2118 
2119         Type falsetype;
2120         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2121         try {
2122             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2123         } finally {
2124             falseEnv.info.scope.leave();
2125         }
2126 
2127         MatchBindings falseBindings = matchBindings;
2128 
2129         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2130                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2131                          List.of(truetype, falsetype)) : pt();
2132         if (condtype.constValue() != null &&
2133                 truetype.constValue() != null &&
2134                 falsetype.constValue() != null &&
2135                 !owntype.hasTag(NONE)) {
2136             //constant folding
2137             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2138         }
2139         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2140         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2141     }
2142     //where
2143         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2144             switch (tree.getTag()) {
2145                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2146                               ((JCLiteral)tree).typetag == BOOLEAN ||
2147                               ((JCLiteral)tree).typetag == BOT;
2148                 case LAMBDA: case REFERENCE: return false;
2149                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2150                 case CONDEXPR:
2151                     JCConditional condTree = (JCConditional)tree;
2152                     return isBooleanOrNumeric(env, condTree.truepart) &&
2153                             isBooleanOrNumeric(env, condTree.falsepart);
2154                 case APPLY:
2155                     JCMethodInvocation speculativeMethodTree =
2156                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2157                                     tree, env, unknownExprInfo,
2158                                     argumentAttr.withLocalCacheContext());
2159                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2160                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2161                             env.enclClass.type :
2162                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2163                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2164                     return primitiveOrBoxed(owntype);
2165                 case NEWCLASS:
2166                     JCExpression className =
2167                             removeClassParams.translate(((JCNewClass)tree).clazz);
2168                     JCExpression speculativeNewClassTree =
2169                             (JCExpression)deferredAttr.attribSpeculative(
2170                                     className, env, unknownTypeInfo,
2171                                     argumentAttr.withLocalCacheContext());
2172                     return primitiveOrBoxed(speculativeNewClassTree.type);
2173                 default:
2174                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2175                             argumentAttr.withLocalCacheContext()).type;
2176                     return primitiveOrBoxed(speculativeType);
2177             }
2178         }
2179         //where
2180             boolean primitiveOrBoxed(Type t) {
2181                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2182             }
2183 
2184             TreeTranslator removeClassParams = new TreeTranslator() {
2185                 @Override
2186                 public void visitTypeApply(JCTypeApply tree) {
2187                     result = translate(tree.clazz);
2188                 }
2189             };
2190 
2191         CheckContext conditionalContext(CheckContext checkContext) {
2192             return new Check.NestedCheckContext(checkContext) {
2193                 //this will use enclosing check context to check compatibility of
2194                 //subexpression against target type; if we are in a method check context,
2195                 //depending on whether boxing is allowed, we could have incompatibilities
2196                 @Override
2197                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2198                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2199                 }
2200             };
2201         }
2202 
2203         /** Compute the type of a conditional expression, after
2204          *  checking that it exists.  See JLS 15.25. Does not take into
2205          *  account the special case where condition and both arms
2206          *  are constants.
2207          *
2208          *  @param pos      The source position to be used for error
2209          *                  diagnostics.
2210          *  @param thentype The type of the expression's then-part.
2211          *  @param elsetype The type of the expression's else-part.
2212          */
2213         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2214             if (condTypes.isEmpty()) {
2215                 return syms.objectType; //TODO: how to handle?
2216             }
2217             Type first = condTypes.head;
2218             // If same type, that is the result
2219             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2220                 return first.baseType();
2221 
2222             List<Type> unboxedTypes = condTypes.stream()
2223                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2224                                                .collect(List.collector());
2225 
2226             // Otherwise, if both arms can be converted to a numeric
2227             // type, return the least numeric type that fits both arms
2228             // (i.e. return larger of the two, or return int if one
2229             // arm is short, the other is char).
2230             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2231                 // If one arm has an integer subrange type (i.e., byte,
2232                 // short, or char), and the other is an integer constant
2233                 // that fits into the subrange, return the subrange type.
2234                 for (Type type : unboxedTypes) {
2235                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2236                         continue;
2237                     }
2238                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2239                         return type.baseType();
2240                 }
2241 
2242                 for (TypeTag tag : primitiveTags) {
2243                     Type candidate = syms.typeOfTag[tag.ordinal()];
2244                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2245                         return candidate;
2246                     }
2247                 }
2248             }
2249 
2250             // Those were all the cases that could result in a primitive
2251             condTypes = condTypes.stream()
2252                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
2253                                  .collect(List.collector());
2254 
2255             for (Type type : condTypes) {
2256                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2257                     return type.baseType();
2258             }
2259 
2260             Iterator<DiagnosticPosition> posIt = positions.iterator();
2261 
2262             condTypes = condTypes.stream()
2263                                  .map(t -> chk.checkNonVoid(posIt.next(), t))
2264                                  .collect(List.collector());
2265 
2266             // both are known to be reference types.  The result is
2267             // lub(thentype,elsetype). This cannot fail, as it will
2268             // always be possible to infer "Object" if nothing better.
2269             return types.lub(condTypes.stream()
2270                         .map(t -> t.baseType())
2271                         .filter(t -> !t.hasTag(BOT))
2272                         .collect(List.collector()));
2273         }
2274 
2275     static final TypeTag[] primitiveTags = new TypeTag[]{
2276         BYTE,
2277         CHAR,
2278         SHORT,
2279         INT,
2280         LONG,
2281         FLOAT,
2282         DOUBLE,
2283         BOOLEAN,
2284     };
2285 
2286     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2287         return bindingEnv(env, env.tree, bindings);
2288     }
2289 
2290     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2291         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2292         bindings.forEach(env1.info.scope::enter);
2293         return env1;
2294     }
2295 
2296     public void visitIf(JCIf tree) {
2297         attribExpr(tree.cond, env, syms.booleanType);
2298 
2299         // if (x) { y } [ else z ]
2300         // include x's bindings when true in y
2301         // include x's bindings when false in z
2302 
2303         MatchBindings condBindings = matchBindings;
2304         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2305 
2306         try {
2307             attribStat(tree.thenpart, thenEnv);
2308         } finally {
2309             thenEnv.info.scope.leave();
2310         }
2311 
2312         preFlow(tree.thenpart);
2313         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2314         boolean aliveAfterElse;
2315 
2316         if (tree.elsepart != null) {
2317             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2318             try {
2319                 attribStat(tree.elsepart, elseEnv);
2320             } finally {
2321                 elseEnv.info.scope.leave();
2322             }
2323             preFlow(tree.elsepart);
2324             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2325         } else {
2326             aliveAfterElse = true;
2327         }
2328 
2329         chk.checkEmptyIf(tree);
2330 
2331         List<BindingSymbol> afterIfBindings = List.nil();
2332 
2333         if (aliveAfterThen && !aliveAfterElse) {
2334             afterIfBindings = condBindings.bindingsWhenTrue;
2335         } else if (aliveAfterElse && !aliveAfterThen) {
2336             afterIfBindings = condBindings.bindingsWhenFalse;
2337         }
2338 
2339         addBindings2Scope(tree, afterIfBindings);
2340 
2341         result = null;
2342     }
2343 
2344         void preFlow(JCTree tree) {
2345             attrRecover.doRecovery();
2346             new PostAttrAnalyzer() {
2347                 @Override
2348                 public void scan(JCTree tree) {
2349                     if (tree == null ||
2350                             (tree.type != null &&
2351                             tree.type == Type.stuckType)) {
2352                         //don't touch stuck expressions!
2353                         return;
2354                     }
2355                     super.scan(tree);
2356                 }
2357 
2358                 @Override
2359                 public void visitClassDef(JCClassDecl that) {
2360                     if (that.sym != null) {
2361                         // Method preFlow shouldn't visit class definitions
2362                         // that have not been entered and attributed.
2363                         // See JDK-8254557 and JDK-8203277 for more details.
2364                         super.visitClassDef(that);
2365                     }
2366                 }
2367 
2368                 @Override
2369                 public void visitLambda(JCLambda that) {
2370                     if (that.type != null) {
2371                         // Method preFlow shouldn't visit lambda expressions
2372                         // that have not been entered and attributed.
2373                         // See JDK-8254557 and JDK-8203277 for more details.
2374                         super.visitLambda(that);
2375                     }
2376                 }
2377             }.scan(tree);
2378         }
2379 
2380     public void visitExec(JCExpressionStatement tree) {
2381         //a fresh environment is required for 292 inference to work properly ---
2382         //see Infer.instantiatePolymorphicSignatureInstance()
2383         Env<AttrContext> localEnv = env.dup(tree);
2384         attribExpr(tree.expr, localEnv);
2385         result = null;
2386     }
2387 
2388     public void visitBreak(JCBreak tree) {
2389         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2390         result = null;
2391     }
2392 
2393     public void visitYield(JCYield tree) {
2394         if (env.info.yieldResult != null) {
2395             attribTree(tree.value, env, env.info.yieldResult);
2396             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2397         } else {
2398             log.error(tree.pos(), tree.value.hasTag(PARENS)
2399                     ? Errors.NoSwitchExpressionQualify
2400                     : Errors.NoSwitchExpression);
2401             attribTree(tree.value, env, unknownExprInfo);
2402         }
2403         result = null;
2404     }
2405 
2406     public void visitContinue(JCContinue tree) {
2407         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2408         result = null;
2409     }
2410     //where
2411         /** Return the target of a break, continue or yield statement,
2412          *  if it exists, report an error if not.
2413          *  Note: The target of a labelled break or continue is the
2414          *  (non-labelled) statement tree referred to by the label,
2415          *  not the tree representing the labelled statement itself.
2416          *
2417          *  @param pos     The position to be used for error diagnostics
2418          *  @param tag     The tag of the jump statement. This is either
2419          *                 Tree.BREAK or Tree.CONTINUE.
2420          *  @param label   The label of the jump statement, or null if no
2421          *                 label is given.
2422          *  @param env     The environment current at the jump statement.
2423          */
2424         private JCTree findJumpTarget(DiagnosticPosition pos,
2425                                                    JCTree.Tag tag,
2426                                                    Name label,
2427                                                    Env<AttrContext> env) {
2428             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2429 
2430             if (jumpTarget.snd != null) {
2431                 log.error(pos, jumpTarget.snd);
2432             }
2433 
2434             return jumpTarget.fst;
2435         }
2436         /** Return the target of a break or continue statement, if it exists,
2437          *  report an error if not.
2438          *  Note: The target of a labelled break or continue is the
2439          *  (non-labelled) statement tree referred to by the label,
2440          *  not the tree representing the labelled statement itself.
2441          *
2442          *  @param tag     The tag of the jump statement. This is either
2443          *                 Tree.BREAK or Tree.CONTINUE.
2444          *  @param label   The label of the jump statement, or null if no
2445          *                 label is given.
2446          *  @param env     The environment current at the jump statement.
2447          */
2448         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2449                                                                        Name label,
2450                                                                        Env<AttrContext> env) {
2451             // Search environments outwards from the point of jump.
2452             Env<AttrContext> env1 = env;
2453             JCDiagnostic.Error pendingError = null;
2454             LOOP:
2455             while (env1 != null) {
2456                 switch (env1.tree.getTag()) {
2457                     case LABELLED:
2458                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2459                         if (label == labelled.label) {
2460                             // If jump is a continue, check that target is a loop.
2461                             if (tag == CONTINUE) {
2462                                 if (!labelled.body.hasTag(DOLOOP) &&
2463                                         !labelled.body.hasTag(WHILELOOP) &&
2464                                         !labelled.body.hasTag(FORLOOP) &&
2465                                         !labelled.body.hasTag(FOREACHLOOP)) {
2466                                     pendingError = Errors.NotLoopLabel(label);
2467                                 }
2468                                 // Found labelled statement target, now go inwards
2469                                 // to next non-labelled tree.
2470                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2471                             } else {
2472                                 return Pair.of(labelled, pendingError);
2473                             }
2474                         }
2475                         break;
2476                     case DOLOOP:
2477                     case WHILELOOP:
2478                     case FORLOOP:
2479                     case FOREACHLOOP:
2480                         if (label == null) return Pair.of(env1.tree, pendingError);
2481                         break;
2482                     case SWITCH:
2483                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2484                         break;
2485                     case SWITCH_EXPRESSION:
2486                         if (tag == YIELD) {
2487                             return Pair.of(env1.tree, null);
2488                         } else if (tag == BREAK) {
2489                             pendingError = Errors.BreakOutsideSwitchExpression;
2490                         } else {
2491                             pendingError = Errors.ContinueOutsideSwitchExpression;
2492                         }
2493                         break;
2494                     case LAMBDA:
2495                     case METHODDEF:
2496                     case CLASSDEF:
2497                         break LOOP;
2498                     default:
2499                 }
2500                 env1 = env1.next;
2501             }
2502             if (label != null)
2503                 return Pair.of(null, Errors.UndefLabel(label));
2504             else if (pendingError != null)
2505                 return Pair.of(null, pendingError);
2506             else if (tag == CONTINUE)
2507                 return Pair.of(null, Errors.ContOutsideLoop);
2508             else
2509                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2510         }
2511 
2512     public void visitReturn(JCReturn tree) {
2513         // Check that there is an enclosing method which is
2514         // nested within than the enclosing class.
2515         if (env.info.returnResult == null) {
2516             log.error(tree.pos(), Errors.RetOutsideMeth);
2517         } else if (env.info.yieldResult != null) {
2518             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2519             if (tree.expr != null) {
2520                 attribExpr(tree.expr, env, env.info.yieldResult.pt);
2521             }
2522         } else if (!env.info.isLambda &&
2523                 env.enclMethod != null &&
2524                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2525             log.error(env.enclMethod,
2526                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2527         } else {
2528             // Attribute return expression, if it exists, and check that
2529             // it conforms to result type of enclosing method.
2530             if (tree.expr != null) {
2531                 if (env.info.returnResult.pt.hasTag(VOID)) {
2532                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2533                               diags.fragment(Fragments.UnexpectedRetVal));
2534                 }
2535                 attribTree(tree.expr, env, env.info.returnResult);
2536             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2537                     !env.info.returnResult.pt.hasTag(NONE)) {
2538                 env.info.returnResult.checkContext.report(tree.pos(),
2539                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2540             }
2541         }
2542         result = null;
2543     }
2544 
2545     public void visitThrow(JCThrow tree) {
2546         Type owntype = attribExpr(tree.expr, env, Type.noType);
2547         chk.checkType(tree, owntype, syms.throwableType);
2548         result = null;
2549     }
2550 
2551     public void visitAssert(JCAssert tree) {
2552         attribExpr(tree.cond, env, syms.booleanType);
2553         if (tree.detail != null) {
2554             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2555         }
2556         result = null;
2557     }
2558 
2559      /** Visitor method for method invocations.
2560      *  NOTE: The method part of an application will have in its type field
2561      *        the return type of the method, not the method's type itself!
2562      */
2563     public void visitApply(JCMethodInvocation tree) {
2564         // The local environment of a method application is
2565         // a new environment nested in the current one.
2566         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2567 
2568         // The types of the actual method arguments.
2569         List<Type> argtypes;
2570 
2571         // The types of the actual method type arguments.
2572         List<Type> typeargtypes = null;
2573 
2574         Name methName = TreeInfo.name(tree.meth);
2575 
2576         boolean isConstructorCall =
2577             methName == names._this || methName == names._super;
2578 
2579         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2580         if (isConstructorCall) {
2581 
2582             // Attribute arguments, yielding list of argument types.
2583             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2584             argtypes = argtypesBuf.toList();
2585             typeargtypes = attribTypes(tree.typeargs, localEnv);
2586 
2587             // Done with this()/super() parameters. End of constructor prologue.
2588             env.info.ctorPrologue = false;
2589 
2590             // Variable `site' points to the class in which the called
2591             // constructor is defined.
2592             Type site = env.enclClass.sym.type;
2593             if (methName == names._super) {
2594                 if (site == syms.objectType) {
2595                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2596                     site = types.createErrorType(syms.objectType);
2597                 } else {
2598                     site = types.supertype(site);
2599                 }
2600             }
2601 
2602             if (site.hasTag(CLASS)) {
2603                 Type encl = site.getEnclosingType();
2604                 while (encl != null && encl.hasTag(TYPEVAR))
2605                     encl = encl.getUpperBound();
2606                 if (encl.hasTag(CLASS)) {
2607                     // we are calling a nested class
2608 
2609                     if (tree.meth.hasTag(SELECT)) {
2610                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2611 
2612                         // We are seeing a prefixed call, of the form
2613                         //     <expr>.super(...).
2614                         // Check that the prefix expression conforms
2615                         // to the outer instance type of the class.
2616                         chk.checkRefType(qualifier.pos(),
2617                                          attribExpr(qualifier, localEnv,
2618                                                     encl));
2619                     }
2620                 } else if (tree.meth.hasTag(SELECT)) {
2621                     log.error(tree.meth.pos(),
2622                               Errors.IllegalQualNotIcls(site.tsym));
2623                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2624                 }
2625 
2626                 if (tree.meth.hasTag(IDENT)) {
2627                     // non-qualified super(...) call; check whether explicit constructor
2628                     // invocation is well-formed. If the super class is an inner class,
2629                     // make sure that an appropriate implicit qualifier exists. If the super
2630                     // class is a local class, make sure that the current class is defined
2631                     // in the same context as the local class.
2632                     checkNewInnerClass(tree.meth.pos(), localEnv, site, true);
2633                 }
2634 
2635                 // if we're calling a java.lang.Enum constructor,
2636                 // prefix the implicit String and int parameters
2637                 if (site.tsym == syms.enumSym)
2638                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
2639 
2640                 // Resolve the called constructor under the assumption
2641                 // that we are referring to a superclass instance of the
2642                 // current instance (JLS ???).
2643                 boolean selectSuperPrev = localEnv.info.selectSuper;
2644                 localEnv.info.selectSuper = true;
2645                 localEnv.info.pendingResolutionPhase = null;
2646                 Symbol sym = rs.resolveConstructor(
2647                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
2648                 localEnv.info.selectSuper = selectSuperPrev;
2649 
2650                 // Set method symbol to resolved constructor...
2651                 TreeInfo.setSymbol(tree.meth, sym);
2652 
2653                 // ...and check that it is legal in the current context.
2654                 // (this will also set the tree's type)
2655                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2656                 checkId(tree.meth, site, sym, localEnv,
2657                         new ResultInfo(kind, mpt));
2658             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
2659                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2660             }
2661             // Otherwise, `site' is an error type and we do nothing
2662             result = tree.type = syms.voidType;
2663         } else {
2664             // Otherwise, we are seeing a regular method call.
2665             // Attribute the arguments, yielding list of argument types, ...
2666             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2667             argtypes = argtypesBuf.toList();
2668             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
2669 
2670             // ... and attribute the method using as a prototype a methodtype
2671             // whose formal argument types is exactly the list of actual
2672             // arguments (this will also set the method symbol).
2673             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2674             localEnv.info.pendingResolutionPhase = null;
2675             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
2676 
2677             // Compute the result type.
2678             Type restype = mtype.getReturnType();
2679             if (restype.hasTag(WILDCARD))
2680                 throw new AssertionError(mtype);
2681 
2682             Type qualifier = (tree.meth.hasTag(SELECT))
2683                     ? ((JCFieldAccess) tree.meth).selected.type
2684                     : env.enclClass.sym.type;
2685             Symbol msym = TreeInfo.symbol(tree.meth);
2686             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
2687 
2688             chk.checkRefTypes(tree.typeargs, typeargtypes);
2689 
2690             // Check that value of resulting type is admissible in the
2691             // current context.  Also, capture the return type
2692             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
2693             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
2694         }
2695         chk.checkRequiresIdentity(tree, env.info.lint);
2696         chk.validate(tree.typeargs, localEnv);
2697     }
2698     //where
2699         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
2700             if (msym != null &&
2701                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
2702                     methodName == names.getClass &&
2703                     argtypes.isEmpty()) {
2704                 // as a special case, x.getClass() has type Class<? extends |X|>
2705                 return new ClassType(restype.getEnclosingType(),
2706                         List.of(new WildcardType(types.erasure(qualifierType.baseType()),
2707                                 BoundKind.EXTENDS,
2708                                 syms.boundClass)),
2709                         restype.tsym,
2710                         restype.getMetadata());
2711             } else if (msym != null &&
2712                     msym.owner == syms.arrayClass &&
2713                     methodName == names.clone &&
2714                     types.isArray(qualifierType)) {
2715                 // as a special case, array.clone() has a result that is
2716                 // the same as static type of the array being cloned
2717                 return qualifierType;
2718             } else {
2719                 return restype;
2720             }
2721         }
2722 
2723         /** Obtain a method type with given argument types.
2724          */
2725         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
2726             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
2727             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
2728         }
2729 
2730     public void visitNewClass(final JCNewClass tree) {
2731         Type owntype = types.createErrorType(tree.type);
2732 
2733         // The local environment of a class creation is
2734         // a new environment nested in the current one.
2735         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2736 
2737         // The anonymous inner class definition of the new expression,
2738         // if one is defined by it.
2739         JCClassDecl cdef = tree.def;
2740 
2741         // If enclosing class is given, attribute it, and
2742         // complete class name to be fully qualified
2743         JCExpression clazz = tree.clazz; // Class field following new
2744         JCExpression clazzid;            // Identifier in class field
2745         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
2746         annoclazzid = null;
2747 
2748         if (clazz.hasTag(TYPEAPPLY)) {
2749             clazzid = ((JCTypeApply) clazz).clazz;
2750             if (clazzid.hasTag(ANNOTATED_TYPE)) {
2751                 annoclazzid = (JCAnnotatedType) clazzid;
2752                 clazzid = annoclazzid.underlyingType;
2753             }
2754         } else {
2755             if (clazz.hasTag(ANNOTATED_TYPE)) {
2756                 annoclazzid = (JCAnnotatedType) clazz;
2757                 clazzid = annoclazzid.underlyingType;
2758             } else {
2759                 clazzid = clazz;
2760             }
2761         }
2762 
2763         JCExpression clazzid1 = clazzid; // The same in fully qualified form
2764 
2765         if (tree.encl != null) {
2766             // We are seeing a qualified new, of the form
2767             //    <expr>.new C <...> (...) ...
2768             // In this case, we let clazz stand for the name of the
2769             // allocated class C prefixed with the type of the qualifier
2770             // expression, so that we can
2771             // resolve it with standard techniques later. I.e., if
2772             // <expr> has type T, then <expr>.new C <...> (...)
2773             // yields a clazz T.C.
2774             Type encltype = chk.checkRefType(tree.encl.pos(),
2775                                              attribExpr(tree.encl, env));
2776             // TODO 308: in <expr>.new C, do we also want to add the type annotations
2777             // from expr to the combined type, or not? Yes, do this.
2778             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
2779                                                  ((JCIdent) clazzid).name);
2780 
2781             EndPosTable endPosTable = this.env.toplevel.endPositions;
2782             endPosTable.storeEnd(clazzid1, clazzid.getEndPosition(endPosTable));
2783             if (clazz.hasTag(ANNOTATED_TYPE)) {
2784                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
2785                 List<JCAnnotation> annos = annoType.annotations;
2786 
2787                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
2788                     clazzid1 = make.at(tree.pos).
2789                         TypeApply(clazzid1,
2790                                   ((JCTypeApply) clazz).arguments);
2791                 }
2792 
2793                 clazzid1 = make.at(tree.pos).
2794                     AnnotatedType(annos, clazzid1);
2795             } else if (clazz.hasTag(TYPEAPPLY)) {
2796                 clazzid1 = make.at(tree.pos).
2797                     TypeApply(clazzid1,
2798                               ((JCTypeApply) clazz).arguments);
2799             }
2800 
2801             clazz = clazzid1;
2802         }
2803 
2804         // Attribute clazz expression and store
2805         // symbol + type back into the attributed tree.
2806         Type clazztype = TreeInfo.isEnumInit(env.tree) ?
2807             attribIdentAsEnumType(env, (JCIdent)clazz) :
2808             attribType(clazz, env);
2809 
2810         clazztype = chk.checkDiamond(tree, clazztype);
2811         chk.validate(clazz, localEnv);
2812         if (tree.encl != null) {
2813             // We have to work in this case to store
2814             // symbol + type back into the attributed tree.
2815             tree.clazz.type = clazztype;
2816             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
2817             clazzid.type = ((JCIdent) clazzid).sym.type;
2818             if (annoclazzid != null) {
2819                 annoclazzid.type = clazzid.type;
2820             }
2821             if (!clazztype.isErroneous()) {
2822                 if (cdef != null && clazztype.tsym.isInterface()) {
2823                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
2824                 } else if (clazztype.tsym.isStatic()) {
2825                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
2826                 }
2827             }
2828         } else {
2829             // Check for the existence of an apropos outer instance
2830             checkNewInnerClass(tree.pos(), env, clazztype, false);
2831         }
2832 
2833         // Attribute constructor arguments.
2834         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2835         final KindSelector pkind =
2836             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2837         List<Type> argtypes = argtypesBuf.toList();
2838         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
2839 
2840         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
2841             // Enums may not be instantiated except implicitly
2842             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
2843                 (!env.tree.hasTag(VARDEF) ||
2844                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
2845                  ((JCVariableDecl) env.tree).init != tree))
2846                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
2847 
2848             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
2849                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
2850             boolean skipNonDiamondPath = false;
2851             // Check that class is not abstract
2852             if (cdef == null && !tree.classDeclRemoved() && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
2853                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
2854                 log.error(tree.pos(),
2855                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
2856                 skipNonDiamondPath = true;
2857             } else if (cdef != null && clazztype.tsym.isInterface()) {
2858                 // Check that no constructor arguments are given to
2859                 // anonymous classes implementing an interface
2860                 if (!argtypes.isEmpty())
2861                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
2862 
2863                 if (!typeargtypes.isEmpty())
2864                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
2865 
2866                 // Error recovery: pretend no arguments were supplied.
2867                 argtypes = List.nil();
2868                 typeargtypes = List.nil();
2869                 skipNonDiamondPath = true;
2870             }
2871             if (TreeInfo.isDiamond(tree)) {
2872                 ClassType site = new ClassType(clazztype.getEnclosingType(),
2873                             clazztype.tsym.type.getTypeArguments(),
2874                                                clazztype.tsym,
2875                                                clazztype.getMetadata());
2876 
2877                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
2878                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
2879                 diamondEnv.info.pendingResolutionPhase = null;
2880 
2881                 //if the type of the instance creation expression is a class type
2882                 //apply method resolution inference (JLS 15.12.2.7). The return type
2883                 //of the resolved constructor will be a partially instantiated type
2884                 Symbol constructor = rs.resolveDiamond(tree.pos(),
2885                             diamondEnv,
2886                             site,
2887                             argtypes,
2888                             typeargtypes);
2889                 tree.constructor = constructor.baseSymbol();
2890 
2891                 final TypeSymbol csym = clazztype.tsym;
2892                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
2893                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
2894                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
2895                 constructorType = checkId(tree, site,
2896                         constructor,
2897                         diamondEnv,
2898                         diamondResult);
2899 
2900                 tree.clazz.type = types.createErrorType(clazztype);
2901                 if (!constructorType.isErroneous()) {
2902                     tree.clazz.type = clazz.type = constructorType.getReturnType();
2903                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
2904                 }
2905                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
2906             }
2907 
2908             // Resolve the called constructor under the assumption
2909             // that we are referring to a superclass instance of the
2910             // current instance (JLS ???).
2911             else if (!skipNonDiamondPath) {
2912                 //the following code alters some of the fields in the current
2913                 //AttrContext - hence, the current context must be dup'ed in
2914                 //order to avoid downstream failures
2915                 Env<AttrContext> rsEnv = localEnv.dup(tree);
2916                 rsEnv.info.selectSuper = cdef != null;
2917                 rsEnv.info.pendingResolutionPhase = null;
2918                 tree.constructor = rs.resolveConstructor(
2919                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
2920                 if (cdef == null) { //do not check twice!
2921                     tree.constructorType = checkId(tree,
2922                             clazztype,
2923                             tree.constructor,
2924                             rsEnv,
2925                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
2926                     if (rsEnv.info.lastResolveVarargs())
2927                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
2928                 }
2929             }
2930 
2931             chk.checkRequiresIdentity(tree, env.info.lint);
2932 
2933             if (cdef != null) {
2934                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
2935                 return;
2936             }
2937 
2938             if (tree.constructor != null && tree.constructor.kind == MTH)
2939                 owntype = clazztype;
2940         }
2941         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2942         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2943         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
2944             //we need to wait for inference to finish and then replace inference vars in the constructor type
2945             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
2946                     instantiatedContext -> {
2947                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2948                     });
2949         }
2950         chk.validate(tree.typeargs, localEnv);
2951     }
2952 
2953         // where
2954         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
2955                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
2956                                                    List<Type> argtypes, List<Type> typeargtypes,
2957                                                    KindSelector pkind) {
2958             // We are seeing an anonymous class instance creation.
2959             // In this case, the class instance creation
2960             // expression
2961             //
2962             //    E.new <typeargs1>C<typargs2>(args) { ... }
2963             //
2964             // is represented internally as
2965             //
2966             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
2967             //
2968             // This expression is then *transformed* as follows:
2969             //
2970             // (1) add an extends or implements clause
2971             // (2) add a constructor.
2972             //
2973             // For instance, if C is a class, and ET is the type of E,
2974             // the expression
2975             //
2976             //    E.new <typeargs1>C<typargs2>(args) { ... }
2977             //
2978             // is translated to (where X is a fresh name and typarams is the
2979             // parameter list of the super constructor):
2980             //
2981             //   new <typeargs1>X(<*nullchk*>E, args) where
2982             //     X extends C<typargs2> {
2983             //       <typarams> X(ET e, args) {
2984             //         e.<typeargs1>super(args)
2985             //       }
2986             //       ...
2987             //     }
2988             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2989             Type enclType = clazztype.getEnclosingType();
2990             if (enclType != null &&
2991                     enclType.hasTag(CLASS) &&
2992                     !chk.checkDenotable((ClassType)enclType)) {
2993                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
2994             }
2995             final boolean isDiamond = TreeInfo.isDiamond(tree);
2996             if (isDiamond
2997                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
2998                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
2999                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
3000                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
3001                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
3002                         instantiatedContext -> {
3003                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
3004                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
3005                             ResultInfo prevResult = this.resultInfo;
3006                             try {
3007                                 this.resultInfo = resultInfoForClassDefinition;
3008                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
3009                                         dupLocalEnv, argtypes, typeargtypes, pkind);
3010                             } finally {
3011                                 this.resultInfo = prevResult;
3012                             }
3013                         });
3014             } else {
3015                 if (isDiamond && clazztype.hasTag(CLASS)) {
3016                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
3017                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
3018                         // One or more types inferred in the previous steps is non-denotable.
3019                         Fragment fragment = Diamond(clazztype.tsym);
3020                         log.error(tree.clazz.pos(),
3021                                 Errors.CantApplyDiamond1(
3022                                         fragment,
3023                                         invalidDiamondArgs.size() > 1 ?
3024                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
3025                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
3026                     }
3027                     // For <>(){}, inferred types must also be accessible.
3028                     for (Type t : clazztype.getTypeArguments()) {
3029                         rs.checkAccessibleType(env, t);
3030                     }
3031                 }
3032 
3033                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
3034                 // false for isInterface call even when the original type is an interface.
3035                 boolean implementing = clazztype.tsym.isInterface() ||
3036                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
3037                         clazztype.getOriginalType().tsym.isInterface();
3038 
3039                 if (implementing) {
3040                     cdef.implementing = List.of(clazz);
3041                 } else {
3042                     cdef.extending = clazz;
3043                 }
3044 
3045                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3046                     rs.isSerializable(clazztype)) {
3047                     localEnv.info.isSerializable = true;
3048                 }
3049 
3050                 attribStat(cdef, localEnv);
3051 
3052                 List<Type> finalargtypes;
3053                 // If an outer instance is given,
3054                 // prefix it to the constructor arguments
3055                 // and delete it from the new expression
3056                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
3057                     finalargtypes = argtypes.prepend(tree.encl.type);
3058                 } else {
3059                     finalargtypes = argtypes;
3060                 }
3061 
3062                 // Reassign clazztype and recompute constructor. As this necessarily involves
3063                 // another attribution pass for deferred types in the case of <>, replicate
3064                 // them. Original arguments have right decorations already.
3065                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3066                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3067                 }
3068 
3069                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3070                                                     : cdef.sym.type;
3071                 Symbol sym = tree.constructor = rs.resolveConstructor(
3072                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3073                 Assert.check(!sym.kind.isResolutionError());
3074                 tree.constructor = sym;
3075                 tree.constructorType = checkId(tree,
3076                         clazztype,
3077                         tree.constructor,
3078                         localEnv,
3079                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3080             }
3081             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3082                                 clazztype : types.createErrorType(tree.type);
3083             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3084             chk.validate(tree.typeargs, localEnv);
3085         }
3086 
3087         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3088             return new Check.NestedCheckContext(checkContext) {
3089                 @Override
3090                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3091                     enclosingContext.report(clazz.clazz,
3092                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3093                 }
3094             };
3095         }
3096 
3097         void checkNewInnerClass(DiagnosticPosition pos, Env<AttrContext> env, Type type, boolean isSuper) {
3098             boolean isLocal = type.tsym.owner.kind == VAR || type.tsym.owner.kind == MTH;
3099             if ((type.tsym.flags() & (INTERFACE | ENUM | RECORD)) != 0 ||
3100                     (!isLocal && !type.tsym.isInner()) ||
3101                     (isSuper && env.enclClass.sym.isAnonymous())) {
3102                 // nothing to check
3103                 return;
3104             }
3105             Symbol res = isLocal ?
3106                     rs.findLocalClassOwner(env, type.tsym) :
3107                     rs.findSelfContaining(pos, env, type.getEnclosingType().tsym, isSuper);
3108             if (res.exists()) {
3109                 rs.accessBase(res, pos, env.enclClass.sym.type, names._this, true);
3110             } else {
3111                 log.error(pos, Errors.EnclClassRequired(type.tsym));
3112             }
3113         }
3114 
3115     /** Make an attributed null check tree.
3116      */
3117     public JCExpression makeNullCheck(JCExpression arg) {
3118         // optimization: new Outer() can never be null; skip null check
3119         if (arg.getTag() == NEWCLASS)
3120             return arg;
3121         // optimization: X.this is never null; skip null check
3122         Name name = TreeInfo.name(arg);
3123         if (name == names._this || name == names._super) return arg;
3124 
3125         JCTree.Tag optag = NULLCHK;
3126         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3127         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3128         tree.type = arg.type;
3129         return tree;
3130     }
3131 
3132     public void visitNewArray(JCNewArray tree) {
3133         Type owntype = types.createErrorType(tree.type);
3134         Env<AttrContext> localEnv = env.dup(tree);
3135         Type elemtype;
3136         if (tree.elemtype != null) {
3137             elemtype = attribType(tree.elemtype, localEnv);
3138             chk.validate(tree.elemtype, localEnv);
3139             owntype = elemtype;
3140             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3141                 attribExpr(l.head, localEnv, syms.intType);
3142                 owntype = new ArrayType(owntype, syms.arrayClass);
3143             }
3144         } else {
3145             // we are seeing an untyped aggregate { ... }
3146             // this is allowed only if the prototype is an array
3147             if (pt().hasTag(ARRAY)) {
3148                 elemtype = types.elemtype(pt());
3149             } else {
3150                 if (!pt().hasTag(ERROR) &&
3151                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3152                     log.error(tree.pos(),
3153                               Errors.IllegalInitializerForType(pt()));
3154                 }
3155                 elemtype = types.createErrorType(pt());
3156             }
3157         }
3158         if (tree.elems != null) {
3159             attribExprs(tree.elems, localEnv, elemtype);
3160             owntype = new ArrayType(elemtype, syms.arrayClass);
3161         }
3162         if (!types.isReifiable(elemtype))
3163             log.error(tree.pos(), Errors.GenericArrayCreation);
3164         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3165     }
3166 
3167     /*
3168      * A lambda expression can only be attributed when a target-type is available.
3169      * In addition, if the target-type is that of a functional interface whose
3170      * descriptor contains inference variables in argument position the lambda expression
3171      * is 'stuck' (see DeferredAttr).
3172      */
3173     @Override
3174     public void visitLambda(final JCLambda that) {
3175         boolean wrongContext = false;
3176         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3177             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3178                 //lambda only allowed in assignment or method invocation/cast context
3179                 log.error(that.pos(), Errors.UnexpectedLambda);
3180             }
3181             resultInfo = recoveryInfo;
3182             wrongContext = true;
3183         }
3184         //create an environment for attribution of the lambda expression
3185         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3186         boolean needsRecovery =
3187                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3188         try {
3189             if (needsRecovery && rs.isSerializable(pt())) {
3190                 localEnv.info.isSerializable = true;
3191                 localEnv.info.isSerializableLambda = true;
3192             }
3193             List<Type> explicitParamTypes = null;
3194             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3195                 //attribute lambda parameters
3196                 attribStats(that.params, localEnv);
3197                 explicitParamTypes = TreeInfo.types(that.params);
3198             }
3199 
3200             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3201             Type currentTarget = targetInfo.target;
3202             Type lambdaType = targetInfo.descriptor;
3203 
3204             if (currentTarget.isErroneous()) {
3205                 result = that.type = currentTarget;
3206                 return;
3207             }
3208 
3209             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3210 
3211             if (lambdaType.hasTag(FORALL)) {
3212                 //lambda expression target desc cannot be a generic method
3213                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3214                                                                     kindName(currentTarget.tsym),
3215                                                                     currentTarget.tsym);
3216                 resultInfo.checkContext.report(that, diags.fragment(msg));
3217                 result = that.type = types.createErrorType(pt());
3218                 return;
3219             }
3220 
3221             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3222                 //add param type info in the AST
3223                 List<Type> actuals = lambdaType.getParameterTypes();
3224                 List<JCVariableDecl> params = that.params;
3225 
3226                 boolean arityMismatch = false;
3227 
3228                 while (params.nonEmpty()) {
3229                     if (actuals.isEmpty()) {
3230                         //not enough actuals to perform lambda parameter inference
3231                         arityMismatch = true;
3232                     }
3233                     //reset previously set info
3234                     Type argType = arityMismatch ?
3235                             syms.errType :
3236                             actuals.head;
3237                     if (params.head.isImplicitlyTyped()) {
3238                         setSyntheticVariableType(params.head, argType);
3239                     }
3240                     params.head.sym = null;
3241                     actuals = actuals.isEmpty() ?
3242                             actuals :
3243                             actuals.tail;
3244                     params = params.tail;
3245                 }
3246 
3247                 //attribute lambda parameters
3248                 attribStats(that.params, localEnv);
3249 
3250                 if (arityMismatch) {
3251                     resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3252                         result = that.type = types.createErrorType(currentTarget);
3253                         return;
3254                 }
3255             }
3256 
3257             //from this point on, no recovery is needed; if we are in assignment context
3258             //we will be able to attribute the whole lambda body, regardless of errors;
3259             //if we are in a 'check' method context, and the lambda is not compatible
3260             //with the target-type, it will be recovered anyway in Attr.checkId
3261             needsRecovery = false;
3262 
3263             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3264                     lambdaBodyResult(that, lambdaType, resultInfo);
3265 
3266             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3267                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3268             } else {
3269                 JCBlock body = (JCBlock)that.body;
3270                 if (body == breakTree &&
3271                         resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3272                     breakTreeFound(copyEnv(localEnv));
3273                 }
3274                 attribStats(body.stats, localEnv);
3275             }
3276 
3277             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3278 
3279             boolean isSpeculativeRound =
3280                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3281 
3282             preFlow(that);
3283             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3284 
3285             that.type = currentTarget; //avoids recovery at this stage
3286             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
3287 
3288             if (!isSpeculativeRound) {
3289                 //add thrown types as bounds to the thrown types free variables if needed:
3290                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3291                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3292                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3293                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3294                     }
3295                 }
3296 
3297                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3298             }
3299             result = wrongContext ? that.type = types.createErrorType(pt())
3300                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3301         } catch (Types.FunctionDescriptorLookupError ex) {
3302             JCDiagnostic cause = ex.getDiagnostic();
3303             resultInfo.checkContext.report(that, cause);
3304             result = that.type = types.createErrorType(pt());
3305             return;
3306         } catch (CompletionFailure cf) {
3307             chk.completionError(that.pos(), cf);
3308         } catch (Throwable t) {
3309             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3310             //as that would likely cause the same exception again.
3311             needsRecovery = false;
3312             throw t;
3313         } finally {
3314             localEnv.info.scope.leave();
3315             if (needsRecovery) {
3316                 Type prevResult = result;
3317                 try {
3318                     attribTree(that, env, recoveryInfo);
3319                 } finally {
3320                     if (result == Type.recoveryType) {
3321                         result = prevResult;
3322                     }
3323                 }
3324             }
3325         }
3326     }
3327     //where
3328         class TargetInfo {
3329             Type target;
3330             Type descriptor;
3331 
3332             public TargetInfo(Type target, Type descriptor) {
3333                 this.target = target;
3334                 this.descriptor = descriptor;
3335             }
3336         }
3337 
3338         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3339             Type lambdaType;
3340             Type currentTarget = resultInfo.pt;
3341             if (resultInfo.pt != Type.recoveryType) {
3342                 /* We need to adjust the target. If the target is an
3343                  * intersection type, for example: SAM & I1 & I2 ...
3344                  * the target will be updated to SAM
3345                  */
3346                 currentTarget = targetChecker.visit(currentTarget, that);
3347                 if (!currentTarget.isIntersection()) {
3348                     if (explicitParamTypes != null) {
3349                         currentTarget = infer.instantiateFunctionalInterface(that,
3350                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3351                     }
3352                     currentTarget = types.removeWildcards(currentTarget);
3353                     lambdaType = types.findDescriptorType(currentTarget);
3354                 } else {
3355                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3356                     ListBuffer<Type> components = new ListBuffer<>();
3357                     for (Type bound : ict.getExplicitComponents()) {
3358                         if (explicitParamTypes != null) {
3359                             try {
3360                                 bound = infer.instantiateFunctionalInterface(that,
3361                                         bound, explicitParamTypes, resultInfo.checkContext);
3362                             } catch (FunctionDescriptorLookupError t) {
3363                                 // do nothing
3364                             }
3365                         }
3366                         if (bound.tsym != syms.objectType.tsym && (!bound.isInterface() || (bound.tsym.flags() & ANNOTATION) != 0)) {
3367                             // bound must be j.l.Object or an interface, but not an annotation
3368                             reportIntersectionError(that, "not.an.intf.component", bound);
3369                         }
3370                         bound = types.removeWildcards(bound);
3371                         components.add(bound);
3372                     }
3373                     currentTarget = types.makeIntersectionType(components.toList());
3374                     currentTarget.tsym.flags_field |= INTERFACE;
3375                     lambdaType = types.findDescriptorType(currentTarget);
3376                 }
3377 
3378             } else {
3379                 currentTarget = Type.recoveryType;
3380                 lambdaType = fallbackDescriptorType(that);
3381             }
3382             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3383                 //lambda expression target desc cannot be a generic method
3384                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3385                                                                     kindName(currentTarget.tsym),
3386                                                                     currentTarget.tsym);
3387                 resultInfo.checkContext.report(that, diags.fragment(msg));
3388                 currentTarget = types.createErrorType(pt());
3389             }
3390             return new TargetInfo(currentTarget, lambdaType);
3391         }
3392 
3393         private void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) {
3394              resultInfo.checkContext.report(pos,
3395                  diags.fragment(Fragments.BadIntersectionTargetForFunctionalExpr(diags.fragment(key, args))));
3396         }
3397 
3398         void preFlow(JCLambda tree) {
3399             attrRecover.doRecovery();
3400             new PostAttrAnalyzer() {
3401                 @Override
3402                 public void scan(JCTree tree) {
3403                     if (tree == null ||
3404                             (tree.type != null &&
3405                             tree.type == Type.stuckType)) {
3406                         //don't touch stuck expressions!
3407                         return;
3408                     }
3409                     super.scan(tree);
3410                 }
3411 
3412                 @Override
3413                 public void visitClassDef(JCClassDecl that) {
3414                     // or class declaration trees!
3415                 }
3416 
3417                 public void visitLambda(JCLambda that) {
3418                     // or lambda expressions!
3419                 }
3420             }.scan(tree.body);
3421         }
3422 
3423         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3424 
3425             @Override
3426             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3427                 return t.isIntersection() ?
3428                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3429             }
3430 
3431             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3432                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3433                 return ict;
3434             }
3435 
3436             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3437                 ListBuffer<Type> targs = new ListBuffer<>();
3438                 ListBuffer<Type> supertypes = new ListBuffer<>();
3439                 for (Type i : ict.interfaces_field) {
3440                     if (i.isParameterized()) {
3441                         targs.appendList(i.tsym.type.allparams());
3442                     }
3443                     supertypes.append(i.tsym.type);
3444                 }
3445                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3446                 notionalIntf.allparams_field = targs.toList();
3447                 notionalIntf.tsym.flags_field |= INTERFACE;
3448                 return notionalIntf.tsym;
3449             }
3450         };
3451 
3452         private Type fallbackDescriptorType(JCExpression tree) {
3453             switch (tree.getTag()) {
3454                 case LAMBDA:
3455                     JCLambda lambda = (JCLambda)tree;
3456                     List<Type> argtypes = List.nil();
3457                     for (JCVariableDecl param : lambda.params) {
3458                         argtypes = param.vartype != null && param.vartype.type != null ?
3459                                 argtypes.append(param.vartype.type) :
3460                                 argtypes.append(syms.errType);
3461                     }
3462                     return new MethodType(argtypes, Type.recoveryType,
3463                             List.of(syms.throwableType), syms.methodClass);
3464                 case REFERENCE:
3465                     return new MethodType(List.nil(), Type.recoveryType,
3466                             List.of(syms.throwableType), syms.methodClass);
3467                 default:
3468                     Assert.error("Cannot get here!");
3469             }
3470             return null;
3471         }
3472 
3473         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3474                 final InferenceContext inferenceContext, final Type... ts) {
3475             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3476         }
3477 
3478         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3479                 final InferenceContext inferenceContext, final List<Type> ts) {
3480             if (inferenceContext.free(ts)) {
3481                 inferenceContext.addFreeTypeListener(ts,
3482                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3483             } else {
3484                 for (Type t : ts) {
3485                     rs.checkAccessibleType(env, t);
3486                 }
3487             }
3488         }
3489 
3490         /**
3491          * Lambda/method reference have a special check context that ensures
3492          * that i.e. a lambda return type is compatible with the expected
3493          * type according to both the inherited context and the assignment
3494          * context.
3495          */
3496         class FunctionalReturnContext extends Check.NestedCheckContext {
3497 
3498             FunctionalReturnContext(CheckContext enclosingContext) {
3499                 super(enclosingContext);
3500             }
3501 
3502             @Override
3503             public boolean compatible(Type found, Type req, Warner warn) {
3504                 //return type must be compatible in both current context and assignment context
3505                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3506             }
3507 
3508             @Override
3509             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3510                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3511             }
3512         }
3513 
3514         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3515 
3516             JCExpression expr;
3517             boolean expStmtExpected;
3518 
3519             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3520                 super(enclosingContext);
3521                 this.expr = expr;
3522             }
3523 
3524             @Override
3525             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3526                 if (expStmtExpected) {
3527                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3528                 } else {
3529                     super.report(pos, details);
3530                 }
3531             }
3532 
3533             @Override
3534             public boolean compatible(Type found, Type req, Warner warn) {
3535                 //a void return is compatible with an expression statement lambda
3536                 if (req.hasTag(VOID)) {
3537                     expStmtExpected = true;
3538                     return TreeInfo.isExpressionStatement(expr);
3539                 } else {
3540                     return super.compatible(found, req, warn);
3541                 }
3542             }
3543         }
3544 
3545         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3546             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3547                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3548                     new FunctionalReturnContext(resultInfo.checkContext);
3549 
3550             return descriptor.getReturnType() == Type.recoveryType ?
3551                     recoveryInfo :
3552                     new ResultInfo(KindSelector.VAL,
3553                             descriptor.getReturnType(), funcContext);
3554         }
3555 
3556         /**
3557         * Lambda compatibility. Check that given return types, thrown types, parameter types
3558         * are compatible with the expected functional interface descriptor. This means that:
3559         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3560         * types must be compatible with the return type of the expected descriptor.
3561         */
3562         void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
3563             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3564 
3565             //return values have already been checked - but if lambda has no return
3566             //values, we must ensure that void/value compatibility is correct;
3567             //this amounts at checking that, if a lambda body can complete normally,
3568             //the descriptor's return type must be void
3569             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3570                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3571                 Fragment msg =
3572                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3573                 checkContext.report(tree,
3574                                     diags.fragment(msg));
3575             }
3576 
3577             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3578             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3579                 checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3580             }
3581         }
3582 
3583         /* This method returns an environment to be used to attribute a lambda
3584          * expression.
3585          *
3586          * The owner of this environment is a method symbol. If the current owner
3587          * is not a method (e.g. if the lambda occurs in a field initializer), then
3588          * a synthetic method symbol owner is created.
3589          */
3590         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3591             Env<AttrContext> lambdaEnv;
3592             Symbol owner = env.info.scope.owner;
3593             if (owner.kind == VAR && owner.owner.kind == TYP) {
3594                 // If the lambda is nested in a field initializer, we need to create a fake init method.
3595                 // Uniqueness of this symbol is not important (as e.g. annotations will be added on the
3596                 // init symbol's owner).
3597                 ClassSymbol enclClass = owner.enclClass();
3598                 Name initName = owner.isStatic() ? names.clinit : names.init;
3599                 MethodSymbol initSym = new MethodSymbol(BLOCK | (owner.isStatic() ? STATIC : 0) | SYNTHETIC | PRIVATE,
3600                         initName, initBlockType, enclClass);
3601                 initSym.params = List.nil();
3602                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(initSym)));
3603             } else {
3604                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3605             }
3606             lambdaEnv.info.yieldResult = null;
3607             lambdaEnv.info.isLambda = true;
3608             return lambdaEnv;
3609         }
3610 
3611     @Override
3612     public void visitReference(final JCMemberReference that) {
3613         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3614             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3615                 //method reference only allowed in assignment or method invocation/cast context
3616                 log.error(that.pos(), Errors.UnexpectedMref);
3617             }
3618             result = that.type = types.createErrorType(pt());
3619             return;
3620         }
3621         final Env<AttrContext> localEnv = env.dup(that);
3622         try {
3623             //attribute member reference qualifier - if this is a constructor
3624             //reference, the expected kind must be a type
3625             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3626 
3627             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3628                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3629                 if (!exprType.isErroneous() &&
3630                     exprType.isRaw() &&
3631                     that.typeargs != null) {
3632                     log.error(that.expr.pos(),
3633                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3634                                                  Fragments.MrefInferAndExplicitParams));
3635                     exprType = types.createErrorType(exprType);
3636                 }
3637             }
3638 
3639             if (exprType.isErroneous()) {
3640                 //if the qualifier expression contains problems,
3641                 //give up attribution of method reference
3642                 result = that.type = exprType;
3643                 return;
3644             }
3645 
3646             if (TreeInfo.isStaticSelector(that.expr, names)) {
3647                 //if the qualifier is a type, validate it; raw warning check is
3648                 //omitted as we don't know at this stage as to whether this is a
3649                 //raw selector (because of inference)
3650                 chk.validate(that.expr, env, false);
3651             } else {
3652                 Symbol lhsSym = TreeInfo.symbol(that.expr);
3653                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
3654             }
3655             //attrib type-arguments
3656             List<Type> typeargtypes = List.nil();
3657             if (that.typeargs != null) {
3658                 typeargtypes = attribTypes(that.typeargs, localEnv);
3659             }
3660 
3661             boolean isTargetSerializable =
3662                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3663                     rs.isSerializable(pt());
3664             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
3665             Type currentTarget = targetInfo.target;
3666             Type desc = targetInfo.descriptor;
3667 
3668             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
3669             List<Type> argtypes = desc.getParameterTypes();
3670             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
3671 
3672             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
3673                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
3674             }
3675 
3676             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
3677             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
3678             try {
3679                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
3680                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
3681                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
3682             } finally {
3683                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
3684             }
3685 
3686             Symbol refSym = refResult.fst;
3687             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
3688 
3689             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
3690              *  JDK-8075541
3691              */
3692             if (refSym.kind != MTH) {
3693                 boolean targetError;
3694                 switch (refSym.kind) {
3695                     case ABSENT_MTH:
3696                         targetError = false;
3697                         break;
3698                     case WRONG_MTH:
3699                     case WRONG_MTHS:
3700                     case AMBIGUOUS:
3701                     case HIDDEN:
3702                     case STATICERR:
3703                         targetError = true;
3704                         break;
3705                     default:
3706                         Assert.error("unexpected result kind " + refSym.kind);
3707                         targetError = false;
3708                 }
3709 
3710                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
3711                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
3712                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
3713 
3714                 JCDiagnostic diag = diags.create(log.currentSource(), that,
3715                         targetError ?
3716                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
3717                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
3718 
3719                 if (targetError && currentTarget == Type.recoveryType) {
3720                     //a target error doesn't make sense during recovery stage
3721                     //as we don't know what actual parameter types are
3722                     result = that.type = currentTarget;
3723                     return;
3724                 } else {
3725                     if (targetError) {
3726                         resultInfo.checkContext.report(that, diag);
3727                     } else {
3728                         log.report(diag);
3729                     }
3730                     result = that.type = types.createErrorType(currentTarget);
3731                     return;
3732                 }
3733             }
3734 
3735             that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
3736             that.kind = lookupHelper.referenceKind(that.sym);
3737             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
3738 
3739             if (desc.getReturnType() == Type.recoveryType) {
3740                 // stop here
3741                 result = that.type = currentTarget;
3742                 return;
3743             }
3744 
3745             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3746                 checkNewInnerClass(that.pos(), env, exprType, false);
3747             }
3748 
3749             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3750 
3751                 if (that.getMode() == ReferenceMode.INVOKE &&
3752                         TreeInfo.isStaticSelector(that.expr, names) &&
3753                         that.kind.isUnbound() &&
3754                         lookupHelper.site.isRaw()) {
3755                     chk.checkRaw(that.expr, localEnv);
3756                 }
3757 
3758                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
3759                         exprType.getTypeArguments().nonEmpty()) {
3760                     //static ref with class type-args
3761                     log.error(that.expr.pos(),
3762                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3763                                                  Fragments.StaticMrefWithTargs));
3764                     result = that.type = types.createErrorType(currentTarget);
3765                     return;
3766                 }
3767 
3768                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
3769                     // Check that super-qualified symbols are not abstract (JLS)
3770                     rs.checkNonAbstract(that.pos(), that.sym);
3771                 }
3772 
3773                 if (isTargetSerializable) {
3774                     chk.checkAccessFromSerializableElement(that, true);
3775                 }
3776             }
3777 
3778             ResultInfo checkInfo =
3779                     resultInfo.dup(newMethodTemplate(
3780                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
3781                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
3782                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3783 
3784             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
3785 
3786             if (that.kind.isUnbound() &&
3787                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
3788                 //re-generate inference constraints for unbound receiver
3789                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
3790                     //cannot happen as this has already been checked - we just need
3791                     //to regenerate the inference constraints, as that has been lost
3792                     //as a result of the call to inferenceContext.save()
3793                     Assert.error("Can't get here");
3794                 }
3795             }
3796 
3797             if (!refType.isErroneous()) {
3798                 refType = types.createMethodTypeWithReturn(refType,
3799                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
3800             }
3801 
3802             //go ahead with standard method reference compatibility check - note that param check
3803             //is a no-op (as this has been taken care during method applicability)
3804             boolean isSpeculativeRound =
3805                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3806 
3807             that.type = currentTarget; //avoids recovery at this stage
3808             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
3809             if (!isSpeculativeRound) {
3810                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
3811             }
3812             chk.checkRequiresIdentity(that, localEnv.info.lint);
3813             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3814         } catch (Types.FunctionDescriptorLookupError ex) {
3815             JCDiagnostic cause = ex.getDiagnostic();
3816             resultInfo.checkContext.report(that, cause);
3817             result = that.type = types.createErrorType(pt());
3818             return;
3819         }
3820     }
3821     //where
3822         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
3823             //if this is a constructor reference, the expected kind must be a type
3824             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
3825                                   KindSelector.VAL_TYP : KindSelector.TYP,
3826                                   Type.noType);
3827         }
3828 
3829 
3830     @SuppressWarnings("fallthrough")
3831     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
3832         InferenceContext inferenceContext = checkContext.inferenceContext();
3833         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
3834 
3835         Type resType;
3836         switch (tree.getMode()) {
3837             case NEW:
3838                 if (!tree.expr.type.isRaw()) {
3839                     resType = tree.expr.type;
3840                     break;
3841                 }
3842             default:
3843                 resType = refType.getReturnType();
3844         }
3845 
3846         Type incompatibleReturnType = resType;
3847 
3848         if (returnType.hasTag(VOID)) {
3849             incompatibleReturnType = null;
3850         }
3851 
3852         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
3853             Type capturedResType = captureMRefReturnType ? types.capture(resType) : resType;
3854             if (resType.isErroneous() ||
3855                     new FunctionalReturnContext(checkContext).compatible(capturedResType, returnType,
3856                             checkContext.checkWarner(tree, capturedResType, returnType))) {
3857                 incompatibleReturnType = null;
3858             }
3859         }
3860 
3861         if (incompatibleReturnType != null) {
3862             Fragment msg =
3863                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
3864             checkContext.report(tree, diags.fragment(msg));
3865         } else {
3866             if (inferenceContext.free(refType)) {
3867                 // we need to wait for inference to finish and then replace inference vars in the referent type
3868                 inferenceContext.addFreeTypeListener(List.of(refType),
3869                         instantiatedContext -> {
3870                             tree.referentType = instantiatedContext.asInstType(refType);
3871                         });
3872             } else {
3873                 tree.referentType = refType;
3874             }
3875         }
3876 
3877         if (!speculativeAttr) {
3878             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
3879                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
3880             }
3881         }
3882     }
3883 
3884     boolean checkExConstraints(
3885             List<Type> thrownByFuncExpr,
3886             List<Type> thrownAtFuncType,
3887             InferenceContext inferenceContext) {
3888         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
3889          *  are not proper types
3890          */
3891         List<Type> nonProperList = thrownAtFuncType.stream()
3892                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
3893         List<Type> properList = thrownAtFuncType.diff(nonProperList);
3894 
3895         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
3896          *  in the throws clause of the invocation type of the method reference's compile-time
3897          *  declaration
3898          */
3899         List<Type> checkedList = thrownByFuncExpr.stream()
3900                 .filter(e -> chk.isChecked(e)).collect(List.collector());
3901 
3902         /** If n = 0 (the function type's throws clause consists only of proper types), then
3903          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
3904          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
3905          *  reduces to true
3906          */
3907         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
3908         for (Type checked : checkedList) {
3909             boolean isSubtype = false;
3910             for (Type proper : properList) {
3911                 if (types.isSubtype(checked, proper)) {
3912                     isSubtype = true;
3913                     break;
3914                 }
3915             }
3916             if (!isSubtype) {
3917                 uncaughtByProperTypes.add(checked);
3918             }
3919         }
3920 
3921         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
3922             return false;
3923         }
3924 
3925         /** If n > 0, the constraint reduces to a set of subtyping constraints:
3926          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
3927          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
3928          */
3929         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
3930         uncaughtByProperTypes.forEach(checkedEx -> {
3931             nonProperAsUndet.forEach(nonProper -> {
3932                 types.isSubtype(checkedEx, nonProper);
3933             });
3934         });
3935 
3936         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
3937          */
3938         nonProperAsUndet.stream()
3939                 .filter(t -> t.hasTag(UNDETVAR))
3940                 .forEach(t -> ((UndetVar)t).setThrow());
3941         return true;
3942     }
3943 
3944     /**
3945      * Set functional type info on the underlying AST. Note: as the target descriptor
3946      * might contain inference variables, we might need to register an hook in the
3947      * current inference context.
3948      */
3949     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
3950             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
3951         if (checkContext.inferenceContext().free(descriptorType)) {
3952             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
3953                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
3954                     inferenceContext.asInstType(primaryTarget), checkContext));
3955         } else {
3956             fExpr.owner = env.info.scope.owner;
3957             if (pt.hasTag(CLASS)) {
3958                 fExpr.target = primaryTarget;
3959             }
3960             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3961                     pt != Type.recoveryType) {
3962                 //check that functional interface class is well-formed
3963                 try {
3964                     /* Types.makeFunctionalInterfaceClass() may throw an exception
3965                      * when it's executed post-inference. See the listener code
3966                      * above.
3967                      */
3968                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
3969                             names.empty, fExpr.target, ABSTRACT);
3970                     if (csym != null) {
3971                         chk.checkImplementations(env.tree, csym, csym);
3972                         try {
3973                             //perform an additional functional interface check on the synthetic class,
3974                             //as there may be spurious errors for raw targets - because of existing issues
3975                             //with membership and inheritance (see JDK-8074570).
3976                             csym.flags_field |= INTERFACE;
3977                             types.findDescriptorType(csym.type);
3978                         } catch (FunctionDescriptorLookupError err) {
3979                             resultInfo.checkContext.report(fExpr,
3980                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
3981                         }
3982                     }
3983                 } catch (Types.FunctionDescriptorLookupError ex) {
3984                     JCDiagnostic cause = ex.getDiagnostic();
3985                     resultInfo.checkContext.report(env.tree, cause);
3986                 }
3987             }
3988         }
3989     }
3990 
3991     public void visitParens(JCParens tree) {
3992         Type owntype = attribTree(tree.expr, env, resultInfo);
3993         result = check(tree, owntype, pkind(), resultInfo);
3994         Symbol sym = TreeInfo.symbol(tree);
3995         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
3996             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
3997     }
3998 
3999     public void visitAssign(JCAssign tree) {
4000         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
4001         Type capturedType = capture(owntype);
4002         attribExpr(tree.rhs, env, owntype);
4003         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
4004     }
4005 
4006     public void visitAssignop(JCAssignOp tree) {
4007         // Attribute arguments.
4008         Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
4009         Type operand = attribExpr(tree.rhs, env);
4010         // Find operator.
4011         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
4012         if (operator != operators.noOpSymbol &&
4013                 !owntype.isErroneous() &&
4014                 !operand.isErroneous()) {
4015             chk.checkDivZero(tree.rhs.pos(), operator, operand);
4016             chk.checkCastable(tree.rhs.pos(),
4017                               operator.type.getReturnType(),
4018                               owntype);
4019             chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
4020             chk.checkOutOfRangeShift(tree.rhs.pos(), operator, operand);
4021         }
4022         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4023     }
4024 
4025     public void visitUnary(JCUnary tree) {
4026         // Attribute arguments.
4027         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
4028             ? attribTree(tree.arg, env, varAssignmentInfo)
4029             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
4030 
4031         // Find operator.
4032         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
4033         Type owntype = types.createErrorType(tree.type);
4034         if (operator != operators.noOpSymbol &&
4035                 !argtype.isErroneous()) {
4036             owntype = (tree.getTag().isIncOrDecUnaryOp())
4037                 ? tree.arg.type
4038                 : operator.type.getReturnType();
4039             int opc = operator.opcode;
4040 
4041             // If the argument is constant, fold it.
4042             if (argtype.constValue() != null) {
4043                 Type ctype = cfolder.fold1(opc, argtype);
4044                 if (ctype != null) {
4045                     owntype = cfolder.coerce(ctype, owntype);
4046                 }
4047             }
4048         }
4049         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4050         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4051     }
4052 
4053     public void visitBinary(JCBinary tree) {
4054         // Attribute arguments.
4055         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4056         // x && y
4057         // include x's bindings when true in y
4058 
4059         // x || y
4060         // include x's bindings when false in y
4061 
4062         MatchBindings lhsBindings = matchBindings;
4063         List<BindingSymbol> propagatedBindings;
4064         switch (tree.getTag()) {
4065             case AND:
4066                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4067                 break;
4068             case OR:
4069                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4070                 break;
4071             default:
4072                 propagatedBindings = List.nil();
4073                 break;
4074         }
4075         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4076         Type right;
4077         try {
4078             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4079         } finally {
4080             rhsEnv.info.scope.leave();
4081         }
4082 
4083         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4084 
4085         // Find operator.
4086         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4087         Type owntype = types.createErrorType(tree.type);
4088         if (operator != operators.noOpSymbol &&
4089                 !left.isErroneous() &&
4090                 !right.isErroneous()) {
4091             owntype = operator.type.getReturnType();
4092             int opc = operator.opcode;
4093             // If both arguments are constants, fold them.
4094             if (left.constValue() != null && right.constValue() != null) {
4095                 Type ctype = cfolder.fold2(opc, left, right);
4096                 if (ctype != null) {
4097                     owntype = cfolder.coerce(ctype, owntype);
4098                 }
4099             }
4100 
4101             // Check that argument types of a reference ==, != are
4102             // castable to each other, (JLS 15.21).  Note: unboxing
4103             // comparisons will not have an acmp* opc at this point.
4104             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4105                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4106                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4107                 }
4108             }
4109 
4110             chk.checkDivZero(tree.rhs.pos(), operator, right);
4111             chk.checkOutOfRangeShift(tree.rhs.pos(), operator, right);
4112         }
4113         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4114     }
4115 
4116     public void visitTypeCast(final JCTypeCast tree) {
4117         Type clazztype = attribType(tree.clazz, env);
4118         chk.validate(tree.clazz, env, false);
4119         chk.checkRequiresIdentity(tree, env.info.lint);
4120         //a fresh environment is required for 292 inference to work properly ---
4121         //see Infer.instantiatePolymorphicSignatureInstance()
4122         Env<AttrContext> localEnv = env.dup(tree);
4123         //should we propagate the target type?
4124         final ResultInfo castInfo;
4125         JCExpression expr = TreeInfo.skipParens(tree.expr);
4126         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4127         if (isPoly) {
4128             //expression is a poly - we need to propagate target type info
4129             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4130                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4131                 @Override
4132                 public boolean compatible(Type found, Type req, Warner warn) {
4133                     return types.isCastable(found, req, warn);
4134                 }
4135             });
4136         } else {
4137             //standalone cast - target-type info is not propagated
4138             castInfo = unknownExprInfo;
4139         }
4140         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4141         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4142         if (exprtype.constValue() != null)
4143             owntype = cfolder.coerce(exprtype, owntype);
4144         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4145         if (!isPoly)
4146             chk.checkRedundantCast(localEnv, tree);
4147     }
4148 
4149     public void visitTypeTest(JCInstanceOf tree) {
4150         Type exprtype = attribExpr(tree.expr, env);
4151         if (exprtype.isPrimitive()) {
4152             preview.checkSourceLevel(tree.expr.pos(), Feature.PRIMITIVE_PATTERNS);
4153         } else {
4154             exprtype = chk.checkNullOrRefType(
4155                     tree.expr.pos(), exprtype);
4156         }
4157         Type clazztype;
4158         JCTree typeTree;
4159         if (tree.pattern.getTag() == BINDINGPATTERN ||
4160             tree.pattern.getTag() == RECORDPATTERN) {
4161             attribExpr(tree.pattern, env, exprtype);
4162             clazztype = tree.pattern.type;
4163             if (types.isSubtype(exprtype, clazztype) &&
4164                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4165                 tree.pattern.getTag() != RECORDPATTERN) {
4166                 if (!allowUnconditionalPatternsInstanceOf) {
4167                     log.error(tree.pos(), Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.error(this.sourceName));
4168                 }
4169             }
4170             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4171         } else {
4172             clazztype = attribType(tree.pattern, env);
4173             typeTree = tree.pattern;
4174             chk.validate(typeTree, env, false);
4175         }
4176         if (clazztype.isPrimitive()) {
4177             preview.checkSourceLevel(tree.pattern.pos(), Feature.PRIMITIVE_PATTERNS);
4178         } else {
4179             if (!clazztype.hasTag(TYPEVAR)) {
4180                 clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4181             }
4182             if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4183                 boolean valid = false;
4184                 if (allowReifiableTypesInInstanceof) {
4185                     valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4186                 } else {
4187                     log.error(tree.pos(), Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4188                     allowReifiableTypesInInstanceof = true;
4189                 }
4190                 if (!valid) {
4191                     clazztype = types.createErrorType(clazztype);
4192                 }
4193             }
4194         }
4195         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4196         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4197     }
4198 
4199     private boolean checkCastablePattern(DiagnosticPosition pos,
4200                                          Type exprType,
4201                                          Type pattType) {
4202         Warner warner = new Warner();
4203         // if any type is erroneous, the problem is reported elsewhere
4204         if (exprType.isErroneous() || pattType.isErroneous()) {
4205             return false;
4206         }
4207         if (!types.isCastable(exprType, pattType, warner)) {
4208             chk.basicHandler.report(pos,
4209                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4210             return false;
4211         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4212                 (!exprType.isPrimitive() || !pattType.isPrimitive() || !types.isSameType(exprType, pattType))) {
4213             preview.checkSourceLevel(pos, Feature.PRIMITIVE_PATTERNS);
4214             return true;
4215         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4216             log.error(pos,
4217                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4218             return false;
4219         } else {
4220             return true;
4221         }
4222     }
4223 
4224     @Override
4225     public void visitAnyPattern(JCAnyPattern tree) {
4226         result = tree.type = resultInfo.pt;
4227     }
4228 
4229     public void visitBindingPattern(JCBindingPattern tree) {
4230         Type type;
4231         if (tree.var.vartype != null) {
4232             type = attribType(tree.var.vartype, env);
4233         } else {
4234             type = resultInfo.pt;
4235         }
4236         tree.type = tree.var.type = type;
4237         BindingSymbol v = new BindingSymbol(tree.var.mods.flags, tree.var.name, type, env.info.scope.owner);
4238         v.pos = tree.pos;
4239         tree.var.sym = v;
4240         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4241             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4242         }
4243         chk.validate(tree.var.vartype, env, true);
4244         if (tree.var.isImplicitlyTyped()) {
4245             setSyntheticVariableType(tree.var, type == Type.noType ? syms.errType
4246                                                                    : type);
4247         }
4248         annotate.annotateLater(tree.var.mods.annotations, env, v);
4249         if (!tree.var.isImplicitlyTyped()) {
4250             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v);
4251         }
4252         annotate.flush();
4253         result = tree.type;
4254         if (v.isUnnamedVariable()) {
4255             matchBindings = MatchBindingsComputer.EMPTY;
4256         } else {
4257             matchBindings = new MatchBindings(List.of(v), List.nil());
4258         }
4259         chk.checkRequiresIdentity(tree, env.info.lint);
4260     }
4261 
4262     @Override
4263     public void visitRecordPattern(JCRecordPattern tree) {
4264         Type site;
4265 
4266         if (tree.deconstructor == null) {
4267             log.error(tree.pos(), Errors.DeconstructionPatternVarNotAllowed);
4268             tree.record = syms.errSymbol;
4269             site = tree.type = types.createErrorType(tree.record.type);
4270         } else {
4271             Type type = attribType(tree.deconstructor, env);
4272             if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4273                 Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4274                 if (inferred == null) {
4275                     log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4276                 } else {
4277                     type = inferred;
4278                 }
4279             }
4280             tree.type = tree.deconstructor.type = type;
4281             site = types.capture(tree.type);
4282         }
4283 
4284         List<Type> expectedRecordTypes;
4285         if (site.tsym.kind == Kind.TYP && ((ClassSymbol) site.tsym).isRecord()) {
4286             ClassSymbol record = (ClassSymbol) site.tsym;
4287             expectedRecordTypes = record.getRecordComponents()
4288                                         .stream()
4289                                         .map(rc -> types.memberType(site, rc))
4290                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4291                                         .collect(List.collector());
4292             tree.record = record;
4293         } else {
4294             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4295             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4296                                 .limit(tree.nested.size())
4297                                 .collect(List.collector());
4298             tree.record = syms.errSymbol;
4299         }
4300         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4301         List<Type> recordTypes = expectedRecordTypes;
4302         List<JCPattern> nestedPatterns = tree.nested;
4303         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4304         try {
4305             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4306                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4307                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4308                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4309                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4310                 nestedPatterns = nestedPatterns.tail;
4311                 recordTypes = recordTypes.tail;
4312             }
4313             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4314                 while (nestedPatterns.nonEmpty()) {
4315                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4316                     nestedPatterns = nestedPatterns.tail;
4317                 }
4318                 List<Type> nestedTypes =
4319                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4320                 log.error(tree.pos(),
4321                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4322                                                                  nestedTypes));
4323             }
4324         } finally {
4325             localEnv.info.scope.leave();
4326         }
4327         chk.validate(tree.deconstructor, env, true);
4328         result = tree.type;
4329         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4330     }
4331 
4332     public void visitIndexed(JCArrayAccess tree) {
4333         Type owntype = types.createErrorType(tree.type);
4334         Type atype = attribExpr(tree.indexed, env);
4335         attribExpr(tree.index, env, syms.intType);
4336         if (types.isArray(atype))
4337             owntype = types.elemtype(atype);
4338         else if (!atype.hasTag(ERROR))
4339             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4340         if (!pkind().contains(KindSelector.VAL))
4341             owntype = capture(owntype);
4342         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4343     }
4344 
4345     public void visitIdent(JCIdent tree) {
4346         Symbol sym;
4347 
4348         // Find symbol
4349         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4350             // If we are looking for a method, the prototype `pt' will be a
4351             // method type with the type of the call's arguments as parameters.
4352             env.info.pendingResolutionPhase = null;
4353             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4354         } else if (tree.sym != null && tree.sym.kind != VAR) {
4355             sym = tree.sym;
4356         } else {
4357             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4358         }
4359         tree.sym = sym;
4360 
4361         // Also find the environment current for the class where
4362         // sym is defined (`symEnv').
4363         Env<AttrContext> symEnv = env;
4364         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4365             sym.kind.matches(KindSelector.VAL_MTH) &&
4366             sym.owner.kind == TYP &&
4367             tree.name != names._this && tree.name != names._super) {
4368 
4369             // Find environment in which identifier is defined.
4370             while (symEnv.outer != null &&
4371                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4372                 symEnv = symEnv.outer;
4373             }
4374         }
4375 
4376         // If symbol is a variable, ...
4377         if (sym.kind == VAR) {
4378             VarSymbol v = (VarSymbol)sym;
4379 
4380             // ..., evaluate its initializer, if it has one, and check for
4381             // illegal forward reference.
4382             checkInit(tree, env, v, false);
4383 
4384             // If we are expecting a variable (as opposed to a value), check
4385             // that the variable is assignable in the current environment.
4386             if (KindSelector.ASG.subset(pkind()))
4387                 checkAssignable(tree.pos(), v, null, env);
4388         }
4389 
4390         Env<AttrContext> env1 = env;
4391         if (sym.kind != ERR && sym.kind != TYP &&
4392             sym.owner != null && sym.owner != env1.enclClass.sym) {
4393             // If the found symbol is inaccessible, then it is
4394             // accessed through an enclosing instance.  Locate this
4395             // enclosing instance:
4396             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4397                 env1 = env1.outer;
4398         }
4399 
4400         if (env.info.isSerializable) {
4401             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4402         }
4403 
4404         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4405     }
4406 
4407     public void visitSelect(JCFieldAccess tree) {
4408         // Determine the expected kind of the qualifier expression.
4409         KindSelector skind = KindSelector.NIL;
4410         if (tree.name == names._this || tree.name == names._super ||
4411                 tree.name == names._class)
4412         {
4413             skind = KindSelector.TYP;
4414         } else {
4415             if (pkind().contains(KindSelector.PCK))
4416                 skind = KindSelector.of(skind, KindSelector.PCK);
4417             if (pkind().contains(KindSelector.TYP))
4418                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4419             if (pkind().contains(KindSelector.VAL_MTH))
4420                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4421         }
4422 
4423         // Attribute the qualifier expression, and determine its symbol (if any).
4424         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
4425         if (!pkind().contains(KindSelector.TYP_PCK))
4426             site = capture(site); // Capture field access
4427 
4428         // don't allow T.class T[].class, etc
4429         if (skind == KindSelector.TYP) {
4430             Type elt = site;
4431             while (elt.hasTag(ARRAY))
4432                 elt = ((ArrayType)elt).elemtype;
4433             if (elt.hasTag(TYPEVAR)) {
4434                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4435                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4436                 tree.sym = tree.type.tsym;
4437                 return ;
4438             }
4439         }
4440 
4441         // If qualifier symbol is a type or `super', assert `selectSuper'
4442         // for the selection. This is relevant for determining whether
4443         // protected symbols are accessible.
4444         Symbol sitesym = TreeInfo.symbol(tree.selected);
4445         boolean selectSuperPrev = env.info.selectSuper;
4446         env.info.selectSuper =
4447             sitesym != null &&
4448             sitesym.name == names._super;
4449 
4450         // Determine the symbol represented by the selection.
4451         env.info.pendingResolutionPhase = null;
4452         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
4453         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4454             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4455             sym = syms.errSymbol;
4456         }
4457         if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
4458             site = capture(site);
4459             sym = selectSym(tree, sitesym, site, env, resultInfo);
4460         }
4461         boolean varArgs = env.info.lastResolveVarargs();
4462         tree.sym = sym;
4463 
4464         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4465             site = types.skipTypeVars(site, true);
4466         }
4467 
4468         // If that symbol is a variable, ...
4469         if (sym.kind == VAR) {
4470             VarSymbol v = (VarSymbol)sym;
4471 
4472             // ..., evaluate its initializer, if it has one, and check for
4473             // illegal forward reference.
4474             checkInit(tree, env, v, true);
4475 
4476             // If we are expecting a variable (as opposed to a value), check
4477             // that the variable is assignable in the current environment.
4478             if (KindSelector.ASG.subset(pkind()))
4479                 checkAssignable(tree.pos(), v, tree.selected, env);
4480         }
4481 
4482         if (sitesym != null &&
4483                 sitesym.kind == VAR &&
4484                 ((VarSymbol)sitesym).isResourceVariable() &&
4485                 sym.kind == MTH &&
4486                 sym.name.equals(names.close) &&
4487                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true)) {
4488             log.warning(tree, LintWarnings.TryExplicitCloseCall);
4489         }
4490 
4491         // Disallow selecting a type from an expression
4492         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4493             tree.type = check(tree.selected, pt(),
4494                               sitesym == null ?
4495                                       KindSelector.VAL : sitesym.kind.toSelector(),
4496                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4497         }
4498 
4499         if (isType(sitesym)) {
4500             if (sym.name != names._this && sym.name != names._super) {
4501                 // Check if type-qualified fields or methods are static (JLS)
4502                 if ((sym.flags() & STATIC) == 0 &&
4503                     sym.name != names._super &&
4504                     (sym.kind == VAR || sym.kind == MTH)) {
4505                     rs.accessBase(rs.new StaticError(sym),
4506                               tree.pos(), site, sym.name, true);
4507                 }
4508             }
4509         } else if (sym.kind != ERR &&
4510                    (sym.flags() & STATIC) != 0 &&
4511                    sym.name != names._class) {
4512             // If the qualified item is not a type and the selected item is static, report
4513             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4514             if (!sym.owner.isAnonymous()) {
4515                 log.warning(tree, LintWarnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4516             } else {
4517                 log.warning(tree, LintWarnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4518             }
4519         }
4520 
4521         // If we are selecting an instance member via a `super', ...
4522         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4523 
4524             // Check that super-qualified symbols are not abstract (JLS)
4525             rs.checkNonAbstract(tree.pos(), sym);
4526 
4527             if (site.isRaw()) {
4528                 // Determine argument types for site.
4529                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
4530                 if (site1 != null) site = site1;
4531             }
4532         }
4533 
4534         if (env.info.isSerializable) {
4535             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4536         }
4537 
4538         env.info.selectSuper = selectSuperPrev;
4539         result = checkId(tree, site, sym, env, resultInfo);
4540     }
4541     //where
4542         /** Determine symbol referenced by a Select expression,
4543          *
4544          *  @param tree   The select tree.
4545          *  @param site   The type of the selected expression,
4546          *  @param env    The current environment.
4547          *  @param resultInfo The current result.
4548          */
4549         private Symbol selectSym(JCFieldAccess tree,
4550                                  Symbol location,
4551                                  Type site,
4552                                  Env<AttrContext> env,
4553                                  ResultInfo resultInfo) {
4554             DiagnosticPosition pos = tree.pos();
4555             Name name = tree.name;
4556             switch (site.getTag()) {
4557             case PACKAGE:
4558                 return rs.accessBase(
4559                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4560                     pos, location, site, name, true);
4561             case ARRAY:
4562             case CLASS:
4563                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4564                     return rs.resolveQualifiedMethod(
4565                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4566                 } else if (name == names._this || name == names._super) {
4567                     return rs.resolveSelf(pos, env, site.tsym, tree);
4568                 } else if (name == names._class) {
4569                     // In this case, we have already made sure in
4570                     // visitSelect that qualifier expression is a type.
4571                     return syms.getClassField(site, types);
4572                 } else {
4573                     // We are seeing a plain identifier as selector.
4574                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
4575                         sym = rs.accessBase(sym, pos, location, site, name, true);
4576                     return sym;
4577                 }
4578             case WILDCARD:
4579                 throw new AssertionError(tree);
4580             case TYPEVAR:
4581                 // Normally, site.getUpperBound() shouldn't be null.
4582                 // It should only happen during memberEnter/attribBase
4583                 // when determining the supertype which *must* be
4584                 // done before attributing the type variables.  In
4585                 // other words, we are seeing this illegal program:
4586                 // class B<T> extends A<T.foo> {}
4587                 Symbol sym = (site.getUpperBound() != null)
4588                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
4589                     : null;
4590                 if (sym == null) {
4591                     log.error(pos, Errors.TypeVarCantBeDeref);
4592                     return syms.errSymbol;
4593                 } else {
4594                     // JLS 4.9 specifies the members are derived by inheritance.
4595                     // We skip inducing a whole class by filtering members that
4596                     // can never be inherited:
4597                     Symbol sym2;
4598                     if (sym.isPrivate()) {
4599                         // Private members
4600                         sym2 = rs.new AccessError(env, site, sym);
4601                     } else if (sym.owner.isInterface() && sym.kind == MTH && (sym.flags() & STATIC) != 0) {
4602                         // Interface static methods
4603                         sym2 = rs.new SymbolNotFoundError(ABSENT_MTH);
4604                     } else {
4605                         sym2 = sym;
4606                     }
4607                     rs.accessBase(sym2, pos, location, site, name, true);
4608                     return sym;
4609                 }
4610             case ERROR:
4611                 // preserve identifier names through errors
4612                 return types.createErrorType(name, site.tsym, site).tsym;
4613             default:
4614                 // The qualifier expression is of a primitive type -- only
4615                 // .class is allowed for these.
4616                 if (name == names._class) {
4617                     // In this case, we have already made sure in Select that
4618                     // qualifier expression is a type.
4619                     return syms.getClassField(site, types);
4620                 } else {
4621                     log.error(pos, Errors.CantDeref(site));
4622                     return syms.errSymbol;
4623                 }
4624             }
4625         }
4626 
4627         /** Determine type of identifier or select expression and check that
4628          *  (1) the referenced symbol is not deprecated
4629          *  (2) the symbol's type is safe (@see checkSafe)
4630          *  (3) if symbol is a variable, check that its type and kind are
4631          *      compatible with the prototype and protokind.
4632          *  (4) if symbol is an instance field of a raw type,
4633          *      which is being assigned to, issue an unchecked warning if its
4634          *      type changes under erasure.
4635          *  (5) if symbol is an instance method of a raw type, issue an
4636          *      unchecked warning if its argument types change under erasure.
4637          *  If checks succeed:
4638          *    If symbol is a constant, return its constant type
4639          *    else if symbol is a method, return its result type
4640          *    otherwise return its type.
4641          *  Otherwise return errType.
4642          *
4643          *  @param tree       The syntax tree representing the identifier
4644          *  @param site       If this is a select, the type of the selected
4645          *                    expression, otherwise the type of the current class.
4646          *  @param sym        The symbol representing the identifier.
4647          *  @param env        The current environment.
4648          *  @param resultInfo    The expected result
4649          */
4650         Type checkId(JCTree tree,
4651                      Type site,
4652                      Symbol sym,
4653                      Env<AttrContext> env,
4654                      ResultInfo resultInfo) {
4655             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
4656                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
4657                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4658         }
4659 
4660         Type checkMethodIdInternal(JCTree tree,
4661                      Type site,
4662                      Symbol sym,
4663                      Env<AttrContext> env,
4664                      ResultInfo resultInfo) {
4665             if (resultInfo.pkind.contains(KindSelector.POLY)) {
4666                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
4667             } else {
4668                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4669             }
4670         }
4671 
4672         Type checkIdInternal(JCTree tree,
4673                      Type site,
4674                      Symbol sym,
4675                      Type pt,
4676                      Env<AttrContext> env,
4677                      ResultInfo resultInfo) {
4678             Type owntype; // The computed type of this identifier occurrence.
4679             switch (sym.kind) {
4680             case TYP:
4681                 // For types, the computed type equals the symbol's type,
4682                 // except for two situations:
4683                 owntype = sym.type;
4684                 if (owntype.hasTag(CLASS)) {
4685                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
4686                     Type ownOuter = owntype.getEnclosingType();
4687 
4688                     // (a) If the symbol's type is parameterized, erase it
4689                     // because no type parameters were given.
4690                     // We recover generic outer type later in visitTypeApply.
4691                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
4692                         owntype = types.erasure(owntype);
4693                     }
4694 
4695                     // (b) If the symbol's type is an inner class, then
4696                     // we have to interpret its outer type as a superclass
4697                     // of the site type. Example:
4698                     //
4699                     // class Tree<A> { class Visitor { ... } }
4700                     // class PointTree extends Tree<Point> { ... }
4701                     // ...PointTree.Visitor...
4702                     //
4703                     // Then the type of the last expression above is
4704                     // Tree<Point>.Visitor.
4705                     else if ((ownOuter.hasTag(CLASS) || ownOuter.hasTag(TYPEVAR)) && site != ownOuter) {
4706                         Type normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
4707                         if (normOuter == null) // perhaps from an import
4708                             normOuter = types.erasure(ownOuter);
4709                         if (normOuter != ownOuter)
4710                             owntype = new ClassType(
4711                                 normOuter, List.nil(), owntype.tsym,
4712                                 owntype.getMetadata());
4713                     }
4714                 }
4715                 break;
4716             case VAR:
4717                 VarSymbol v = (VarSymbol)sym;
4718 
4719                 if (env.info.enclVar != null
4720                         && v.type.hasTag(NONE)) {
4721                     //self reference to implicitly typed variable declaration
4722                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
4723                     return tree.type = v.type = types.createErrorType(v.type);
4724                 }
4725 
4726                 // Test (4): if symbol is an instance field of a raw type,
4727                 // which is being assigned to, issue an unchecked warning if
4728                 // its type changes under erasure.
4729                 if (KindSelector.ASG.subset(pkind()) &&
4730                     v.owner.kind == TYP &&
4731                     (v.flags() & STATIC) == 0 &&
4732                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4733                     Type s = types.asOuterSuper(site, v.owner);
4734                     if (s != null &&
4735                         s.isRaw() &&
4736                         !types.isSameType(v.type, v.erasure(types))) {
4737                         chk.warnUnchecked(tree.pos(), LintWarnings.UncheckedAssignToVar(v, s));
4738                     }
4739                 }
4740                 // The computed type of a variable is the type of the
4741                 // variable symbol, taken as a member of the site type.
4742                 owntype = (sym.owner.kind == TYP &&
4743                            sym.name != names._this && sym.name != names._super)
4744                     ? types.memberType(site, sym)
4745                     : sym.type;
4746 
4747                 // If the variable is a constant, record constant value in
4748                 // computed type.
4749                 if (v.getConstValue() != null && isStaticReference(tree))
4750                     owntype = owntype.constType(v.getConstValue());
4751 
4752                 if (resultInfo.pkind == KindSelector.VAL) {
4753                     owntype = capture(owntype); // capture "names as expressions"
4754                 }
4755                 break;
4756             case MTH: {
4757                 owntype = checkMethod(site, sym,
4758                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
4759                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
4760                         resultInfo.pt.getTypeArguments());
4761                 chk.checkRestricted(tree.pos(), sym);
4762                 break;
4763             }
4764             case PCK: case ERR:
4765                 owntype = sym.type;
4766                 break;
4767             default:
4768                 throw new AssertionError("unexpected kind: " + sym.kind +
4769                                          " in tree " + tree);
4770             }
4771 
4772             // Emit a `deprecation' warning if symbol is deprecated.
4773             // (for constructors (but not for constructor references), the error
4774             // was given when the constructor was resolved)
4775 
4776             if (sym.name != names.init || tree.hasTag(REFERENCE)) {
4777                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
4778                 chk.checkSunAPI(tree.pos(), sym);
4779                 chk.checkProfile(tree.pos(), sym);
4780                 chk.checkPreview(tree.pos(), env.info.scope.owner, site, sym);
4781             }
4782 
4783             if (pt.isErroneous()) {
4784                 owntype = types.createErrorType(owntype);
4785             }
4786 
4787             // If symbol is a variable, check that its type and
4788             // kind are compatible with the prototype and protokind.
4789             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
4790         }
4791 
4792         /** Check that variable is initialized and evaluate the variable's
4793          *  initializer, if not yet done. Also check that variable is not
4794          *  referenced before it is defined.
4795          *  @param tree    The tree making up the variable reference.
4796          *  @param env     The current environment.
4797          *  @param v       The variable's symbol.
4798          */
4799         private void checkInit(JCTree tree,
4800                                Env<AttrContext> env,
4801                                VarSymbol v,
4802                                boolean onlyWarning) {
4803             // A forward reference is diagnosed if the declaration position
4804             // of the variable is greater than the current tree position
4805             // and the tree and variable definition occur in the same class
4806             // definition.  Note that writes don't count as references.
4807             // This check applies only to class and instance
4808             // variables.  Local variables follow different scope rules,
4809             // and are subject to definite assignment checking.
4810             Env<AttrContext> initEnv = enclosingInitEnv(env);
4811             if (initEnv != null &&
4812                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
4813                 v.owner.kind == TYP &&
4814                 v.owner == env.info.scope.owner.enclClass() &&
4815                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
4816                 (!env.tree.hasTag(ASSIGN) ||
4817                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
4818                 if (!onlyWarning || isStaticEnumField(v)) {
4819                     Error errkey = (initEnv.info.enclVar == v) ?
4820                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
4821                     log.error(tree.pos(), errkey);
4822                 } else if (useBeforeDeclarationWarning) {
4823                     Warning warnkey = (initEnv.info.enclVar == v) ?
4824                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
4825                     log.warning(tree.pos(), warnkey);
4826                 }
4827             }
4828 
4829             v.getConstValue(); // ensure initializer is evaluated
4830 
4831             checkEnumInitializer(tree, env, v);
4832         }
4833 
4834         /**
4835          * Returns the enclosing init environment associated with this env (if any). An init env
4836          * can be either a field declaration env or a static/instance initializer env.
4837          */
4838         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
4839             while (true) {
4840                 switch (env.tree.getTag()) {
4841                     case VARDEF:
4842                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
4843                         if (vdecl.sym.owner.kind == TYP) {
4844                             //field
4845                             return env;
4846                         }
4847                         break;
4848                     case BLOCK:
4849                         if (env.next.tree.hasTag(CLASSDEF)) {
4850                             //instance/static initializer
4851                             return env;
4852                         }
4853                         break;
4854                     case METHODDEF:
4855                     case CLASSDEF:
4856                     case TOPLEVEL:
4857                         return null;
4858                 }
4859                 Assert.checkNonNull(env.next);
4860                 env = env.next;
4861             }
4862         }
4863 
4864         /**
4865          * Check for illegal references to static members of enum.  In
4866          * an enum type, constructors and initializers may not
4867          * reference its static members unless they are constant.
4868          *
4869          * @param tree    The tree making up the variable reference.
4870          * @param env     The current environment.
4871          * @param v       The variable's symbol.
4872          * @jls 8.9 Enum Types
4873          */
4874         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
4875             // JLS:
4876             //
4877             // "It is a compile-time error to reference a static field
4878             // of an enum type that is not a compile-time constant
4879             // (15.28) from constructors, instance initializer blocks,
4880             // or instance variable initializer expressions of that
4881             // type. It is a compile-time error for the constructors,
4882             // instance initializer blocks, or instance variable
4883             // initializer expressions of an enum constant e to refer
4884             // to itself or to an enum constant of the same type that
4885             // is declared to the right of e."
4886             if (isStaticEnumField(v)) {
4887                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
4888 
4889                 if (enclClass == null || enclClass.owner == null)
4890                     return;
4891 
4892                 // See if the enclosing class is the enum (or a
4893                 // subclass thereof) declaring v.  If not, this
4894                 // reference is OK.
4895                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
4896                     return;
4897 
4898                 // If the reference isn't from an initializer, then
4899                 // the reference is OK.
4900                 if (!Resolve.isInitializer(env))
4901                     return;
4902 
4903                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
4904             }
4905         }
4906 
4907         /** Is the given symbol a static, non-constant field of an Enum?
4908          *  Note: enum literals should not be regarded as such
4909          */
4910         private boolean isStaticEnumField(VarSymbol v) {
4911             return Flags.isEnum(v.owner) &&
4912                    Flags.isStatic(v) &&
4913                    !Flags.isConstant(v) &&
4914                    v.name != names._class;
4915         }
4916 
4917     /**
4918      * Check that method arguments conform to its instantiation.
4919      **/
4920     public Type checkMethod(Type site,
4921                             final Symbol sym,
4922                             ResultInfo resultInfo,
4923                             Env<AttrContext> env,
4924                             final List<JCExpression> argtrees,
4925                             List<Type> argtypes,
4926                             List<Type> typeargtypes) {
4927         // Test (5): if symbol is an instance method of a raw type, issue
4928         // an unchecked warning if its argument types change under erasure.
4929         if ((sym.flags() & STATIC) == 0 &&
4930             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4931             Type s = types.asOuterSuper(site, sym.owner);
4932             if (s != null && s.isRaw() &&
4933                 !types.isSameTypes(sym.type.getParameterTypes(),
4934                                    sym.erasure(types).getParameterTypes())) {
4935                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedCallMbrOfRawType(sym, s));
4936             }
4937         }
4938 
4939         if (env.info.defaultSuperCallSite != null) {
4940             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
4941                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
4942                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
4943                 List<MethodSymbol> icand_sup =
4944                         types.interfaceCandidates(sup, (MethodSymbol)sym);
4945                 if (icand_sup.nonEmpty() &&
4946                         icand_sup.head != sym &&
4947                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
4948                     log.error(env.tree.pos(),
4949                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
4950                     break;
4951                 }
4952             }
4953             env.info.defaultSuperCallSite = null;
4954         }
4955 
4956         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
4957             JCMethodInvocation app = (JCMethodInvocation)env.tree;
4958             if (app.meth.hasTag(SELECT) &&
4959                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
4960                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
4961             }
4962         }
4963 
4964         // Compute the identifier's instantiated type.
4965         // For methods, we need to compute the instance type by
4966         // Resolve.instantiate from the symbol's type as well as
4967         // any type arguments and value arguments.
4968         Warner noteWarner = new Warner();
4969         try {
4970             Type owntype = rs.checkMethod(
4971                     env,
4972                     site,
4973                     sym,
4974                     resultInfo,
4975                     argtypes,
4976                     typeargtypes,
4977                     noteWarner);
4978 
4979             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
4980                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
4981 
4982             argtypes = argtypes.map(checkDeferredMap);
4983 
4984             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
4985                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedMethInvocationApplied(kindName(sym),
4986                         sym.name,
4987                         rs.methodArguments(sym.type.getParameterTypes()),
4988                         rs.methodArguments(argtypes.map(checkDeferredMap)),
4989                         kindName(sym.location()),
4990                         sym.location()));
4991                 if (resultInfo.pt != Infer.anyPoly ||
4992                         !owntype.hasTag(METHOD) ||
4993                         !owntype.isPartial()) {
4994                     //if this is not a partially inferred method type, erase return type. Otherwise,
4995                     //erasure is carried out in PartiallyInferredMethodType.check().
4996                     owntype = new MethodType(owntype.getParameterTypes(),
4997                             types.erasure(owntype.getReturnType()),
4998                             types.erasure(owntype.getThrownTypes()),
4999                             syms.methodClass);
5000                 }
5001             }
5002 
5003             PolyKind pkind = (sym.type.hasTag(FORALL) &&
5004                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
5005                  PolyKind.POLY : PolyKind.STANDALONE;
5006             TreeInfo.setPolyKind(env.tree, pkind);
5007 
5008             return (resultInfo.pt == Infer.anyPoly) ?
5009                     owntype :
5010                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
5011                             resultInfo.checkContext.inferenceContext());
5012         } catch (Infer.InferenceException ex) {
5013             //invalid target type - propagate exception outwards or report error
5014             //depending on the current check context
5015             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
5016             return types.createErrorType(site);
5017         } catch (Resolve.InapplicableMethodException ex) {
5018             final JCDiagnostic diag = ex.getDiagnostic();
5019             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
5020                 @Override
5021                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
5022                     return new Pair<>(sym, diag);
5023                 }
5024             };
5025             List<Type> argtypes2 = argtypes.map(
5026                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
5027             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
5028                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
5029             log.report(errDiag);
5030             return types.createErrorType(site);
5031         }
5032     }
5033 
5034     public void visitLiteral(JCLiteral tree) {
5035         result = check(tree, litType(tree.typetag).constType(tree.value),
5036                 KindSelector.VAL, resultInfo);
5037     }
5038     //where
5039     /** Return the type of a literal with given type tag.
5040      */
5041     Type litType(TypeTag tag) {
5042         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
5043     }
5044 
5045     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5046         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5047     }
5048 
5049     public void visitTypeArray(JCArrayTypeTree tree) {
5050         Type etype = attribType(tree.elemtype, env);
5051         Type type = new ArrayType(etype, syms.arrayClass);
5052         result = check(tree, type, KindSelector.TYP, resultInfo);
5053     }
5054 
5055     /** Visitor method for parameterized types.
5056      *  Bound checking is left until later, since types are attributed
5057      *  before supertype structure is completely known
5058      */
5059     public void visitTypeApply(JCTypeApply tree) {
5060         Type owntype = types.createErrorType(tree.type);
5061 
5062         // Attribute functor part of application and make sure it's a class.
5063         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5064 
5065         // Attribute type parameters
5066         List<Type> actuals = attribTypes(tree.arguments, env);
5067 
5068         if (clazztype.hasTag(CLASS)) {
5069             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5070             if (actuals.isEmpty()) //diamond
5071                 actuals = formals;
5072 
5073             if (actuals.length() == formals.length()) {
5074                 List<Type> a = actuals;
5075                 List<Type> f = formals;
5076                 while (a.nonEmpty()) {
5077                     a.head = a.head.withTypeVar(f.head);
5078                     a = a.tail;
5079                     f = f.tail;
5080                 }
5081                 // Compute the proper generic outer
5082                 Type clazzOuter = clazztype.getEnclosingType();
5083                 if (clazzOuter.hasTag(CLASS)) {
5084                     Type site;
5085                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5086                     if (clazz.hasTag(IDENT)) {
5087                         site = env.enclClass.sym.type;
5088                     } else if (clazz.hasTag(SELECT)) {
5089                         site = ((JCFieldAccess) clazz).selected.type;
5090                     } else throw new AssertionError(""+tree);
5091                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5092                         if (site.hasTag(CLASS) || site.hasTag(TYPEVAR))
5093                             site = types.asEnclosingSuper(site, clazzOuter.tsym);
5094                         if (site == null)
5095                             site = types.erasure(clazzOuter);
5096                         clazzOuter = site;
5097                     }
5098                 }
5099                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5100                                         clazztype.getMetadata());
5101             } else {
5102                 if (formals.length() != 0) {
5103                     log.error(tree.pos(),
5104                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5105                 } else {
5106                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5107                 }
5108                 owntype = types.createErrorType(tree.type);
5109             }
5110         } else if (clazztype.hasTag(ERROR)) {
5111             ErrorType parameterizedErroneous =
5112                     new ErrorType(clazztype.getOriginalType(),
5113                                   clazztype.tsym,
5114                                   clazztype.getMetadata());
5115 
5116             parameterizedErroneous.typarams_field = actuals;
5117             owntype = parameterizedErroneous;
5118         }
5119         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5120     }
5121 
5122     public void visitTypeUnion(JCTypeUnion tree) {
5123         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5124         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5125         for (JCExpression typeTree : tree.alternatives) {
5126             Type ctype = attribType(typeTree, env);
5127             ctype = chk.checkType(typeTree.pos(),
5128                           chk.checkClassType(typeTree.pos(), ctype),
5129                           syms.throwableType);
5130             if (!ctype.isErroneous()) {
5131                 //check that alternatives of a union type are pairwise
5132                 //unrelated w.r.t. subtyping
5133                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5134                     for (Type t : multicatchTypes) {
5135                         boolean sub = types.isSubtype(ctype, t);
5136                         boolean sup = types.isSubtype(t, ctype);
5137                         if (sub || sup) {
5138                             //assume 'a' <: 'b'
5139                             Type a = sub ? ctype : t;
5140                             Type b = sub ? t : ctype;
5141                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5142                         }
5143                     }
5144                 }
5145                 multicatchTypes.append(ctype);
5146                 if (all_multicatchTypes != null)
5147                     all_multicatchTypes.append(ctype);
5148             } else {
5149                 if (all_multicatchTypes == null) {
5150                     all_multicatchTypes = new ListBuffer<>();
5151                     all_multicatchTypes.appendList(multicatchTypes);
5152                 }
5153                 all_multicatchTypes.append(ctype);
5154             }
5155         }
5156         Type t = check(tree, types.lub(multicatchTypes.toList()),
5157                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5158         if (t.hasTag(CLASS)) {
5159             List<Type> alternatives =
5160                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5161             t = new UnionClassType((ClassType) t, alternatives);
5162         }
5163         tree.type = result = t;
5164     }
5165 
5166     public void visitTypeIntersection(JCTypeIntersection tree) {
5167         attribTypes(tree.bounds, env);
5168         tree.type = result = checkIntersection(tree, tree.bounds);
5169     }
5170 
5171     public void visitTypeParameter(JCTypeParameter tree) {
5172         TypeVar typeVar = (TypeVar) tree.type;
5173 
5174         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5175             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5176         }
5177 
5178         if (!typeVar.getUpperBound().isErroneous()) {
5179             //fixup type-parameter bound computed in 'attribTypeVariables'
5180             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5181         }
5182     }
5183 
5184     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5185         Set<Symbol> boundSet = new HashSet<>();
5186         if (bounds.nonEmpty()) {
5187             // accept class or interface or typevar as first bound.
5188             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5189             boundSet.add(types.erasure(bounds.head.type).tsym);
5190             if (bounds.head.type.isErroneous()) {
5191                 return bounds.head.type;
5192             }
5193             else if (bounds.head.type.hasTag(TYPEVAR)) {
5194                 // if first bound was a typevar, do not accept further bounds.
5195                 if (bounds.tail.nonEmpty()) {
5196                     log.error(bounds.tail.head.pos(),
5197                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5198                     return bounds.head.type;
5199                 }
5200             } else {
5201                 // if first bound was a class or interface, accept only interfaces
5202                 // as further bounds.
5203                 for (JCExpression bound : bounds.tail) {
5204                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5205                     if (bound.type.isErroneous()) {
5206                         bounds = List.of(bound);
5207                     }
5208                     else if (bound.type.hasTag(CLASS)) {
5209                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5210                     }
5211                 }
5212             }
5213         }
5214 
5215         if (bounds.length() == 0) {
5216             return syms.objectType;
5217         } else if (bounds.length() == 1) {
5218             return bounds.head.type;
5219         } else {
5220             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5221             // ... the variable's bound is a class type flagged COMPOUND
5222             // (see comment for TypeVar.bound).
5223             // In this case, generate a class tree that represents the
5224             // bound class, ...
5225             JCExpression extending;
5226             List<JCExpression> implementing;
5227             if (!bounds.head.type.isInterface()) {
5228                 extending = bounds.head;
5229                 implementing = bounds.tail;
5230             } else {
5231                 extending = null;
5232                 implementing = bounds;
5233             }
5234             JCClassDecl cd = make.at(tree).ClassDef(
5235                 make.Modifiers(PUBLIC | ABSTRACT),
5236                 names.empty, List.nil(),
5237                 extending, implementing, List.nil());
5238 
5239             ClassSymbol c = (ClassSymbol)owntype.tsym;
5240             Assert.check((c.flags() & COMPOUND) != 0);
5241             cd.sym = c;
5242             c.sourcefile = env.toplevel.sourcefile;
5243 
5244             // ... and attribute the bound class
5245             c.flags_field |= UNATTRIBUTED;
5246             Env<AttrContext> cenv = enter.classEnv(cd, env);
5247             typeEnvs.put(c, cenv);
5248             attribClass(c);
5249             return owntype;
5250         }
5251     }
5252 
5253     public void visitWildcard(JCWildcard tree) {
5254         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5255         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5256             ? syms.objectType
5257             : attribType(tree.inner, env);
5258         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
5259                                               tree.kind.kind,
5260                                               syms.boundClass),
5261                 KindSelector.TYP, resultInfo);
5262     }
5263 
5264     public void visitAnnotation(JCAnnotation tree) {
5265         Assert.error("should be handled in annotate");
5266     }
5267 
5268     @Override
5269     public void visitModifiers(JCModifiers tree) {
5270         //error recovery only:
5271         Assert.check(resultInfo.pkind == KindSelector.ERR);
5272 
5273         attribAnnotationTypes(tree.annotations, env);
5274     }
5275 
5276     public void visitAnnotatedType(JCAnnotatedType tree) {
5277         attribAnnotationTypes(tree.annotations, env);
5278         Type underlyingType = attribType(tree.underlyingType, env);
5279         Type annotatedType = underlyingType.preannotatedType();
5280 
5281         annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5282         result = tree.type = annotatedType;
5283     }
5284 
5285     public void visitErroneous(JCErroneous tree) {
5286         if (tree.errs != null) {
5287             WriteableScope newScope = env.info.scope;
5288 
5289             if (env.tree instanceof JCClassDecl) {
5290                 Symbol fakeOwner =
5291                     new MethodSymbol(BLOCK, names.empty, null,
5292                         env.info.scope.owner);
5293                 newScope = newScope.dupUnshared(fakeOwner);
5294             }
5295 
5296             Env<AttrContext> errEnv =
5297                     env.dup(env.tree,
5298                             env.info.dup(newScope));
5299             errEnv.info.returnResult = unknownExprInfo;
5300             for (JCTree err : tree.errs)
5301                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5302         }
5303         result = tree.type = syms.errType;
5304     }
5305 
5306     /** Default visitor method for all other trees.
5307      */
5308     public void visitTree(JCTree tree) {
5309         throw new AssertionError();
5310     }
5311 
5312     /**
5313      * Attribute an env for either a top level tree or class or module declaration.
5314      */
5315     public void attrib(Env<AttrContext> env) {
5316         switch (env.tree.getTag()) {
5317             case MODULEDEF:
5318                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5319                 break;
5320             case PACKAGEDEF:
5321                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5322                 break;
5323             default:
5324                 attribClass(env.tree.pos(), env.enclClass.sym);
5325         }
5326 
5327         annotate.flush();
5328 
5329         // Now that this tree is attributed, we can calculate the Lint configuration everywhere within it
5330         lintMapper.calculateLints(env.toplevel.sourcefile, env.tree, env.toplevel.endPositions);
5331     }
5332 
5333     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5334         try {
5335             annotate.flush();
5336             attribPackage(p);
5337         } catch (CompletionFailure ex) {
5338             chk.completionError(pos, ex);
5339         }
5340     }
5341 
5342     void attribPackage(PackageSymbol p) {
5343         attribWithLint(p,
5344                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5345     }
5346 
5347     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5348         try {
5349             annotate.flush();
5350             attribModule(m);
5351         } catch (CompletionFailure ex) {
5352             chk.completionError(pos, ex);
5353         }
5354     }
5355 
5356     void attribModule(ModuleSymbol m) {
5357         attribWithLint(m, env -> attribStat(env.tree, env));
5358     }
5359 
5360     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5361         Env<AttrContext> env = typeEnvs.get(sym);
5362 
5363         Env<AttrContext> lintEnv = env;
5364         while (lintEnv.info.lint == null)
5365             lintEnv = lintEnv.next;
5366 
5367         Lint lint = lintEnv.info.lint.augment(sym);
5368 
5369         Lint prevLint = chk.setLint(lint);
5370         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5371 
5372         try {
5373             attrib.accept(env);
5374         } finally {
5375             log.useSource(prev);
5376             chk.setLint(prevLint);
5377         }
5378     }
5379 
5380     /** Main method: attribute class definition associated with given class symbol.
5381      *  reporting completion failures at the given position.
5382      *  @param pos The source position at which completion errors are to be
5383      *             reported.
5384      *  @param c   The class symbol whose definition will be attributed.
5385      */
5386     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5387         try {
5388             annotate.flush();
5389             attribClass(c);
5390         } catch (CompletionFailure ex) {
5391             chk.completionError(pos, ex);
5392         }
5393     }
5394 
5395     /** Attribute class definition associated with given class symbol.
5396      *  @param c   The class symbol whose definition will be attributed.
5397      */
5398     void attribClass(ClassSymbol c) throws CompletionFailure {
5399         if (c.type.hasTag(ERROR)) return;
5400 
5401         // Check for cycles in the inheritance graph, which can arise from
5402         // ill-formed class files.
5403         chk.checkNonCyclic(null, c.type);
5404 
5405         Type st = types.supertype(c.type);
5406         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5407             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0) {
5408             // First, attribute superclass.
5409             if (st.hasTag(CLASS))
5410                 attribClass((ClassSymbol)st.tsym);
5411 
5412             // Next attribute owner, if it is a class.
5413             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5414                 attribClass((ClassSymbol)c.owner);
5415 
5416             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5417         }
5418 
5419         // The previous operations might have attributed the current class
5420         // if there was a cycle. So we test first whether the class is still
5421         // UNATTRIBUTED.
5422         if ((c.flags_field & UNATTRIBUTED) != 0) {
5423             c.flags_field &= ~UNATTRIBUTED;
5424 
5425             // Get environment current at the point of class definition.
5426             Env<AttrContext> env = typeEnvs.get(c);
5427 
5428             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5429             // because the annotations were not available at the time the env was created. Therefore,
5430             // we look up the environment chain for the first enclosing environment for which the
5431             // lint value is set. Typically, this is the parent env, but might be further if there
5432             // are any envs created as a result of TypeParameter nodes.
5433             Env<AttrContext> lintEnv = env;
5434             while (lintEnv.info.lint == null)
5435                 lintEnv = lintEnv.next;
5436 
5437             // Having found the enclosing lint value, we can initialize the lint value for this class
5438             env.info.lint = lintEnv.info.lint.augment(c);
5439 
5440             Lint prevLint = chk.setLint(env.info.lint);
5441             JavaFileObject prev = log.useSource(c.sourcefile);
5442             ResultInfo prevReturnRes = env.info.returnResult;
5443 
5444             try {
5445                 if (c.isSealed() &&
5446                         !c.isEnum() &&
5447                         !c.isPermittedExplicit &&
5448                         c.getPermittedSubclasses().isEmpty()) {
5449                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5450                 }
5451 
5452                 if (c.isSealed()) {
5453                     Set<Symbol> permittedTypes = new HashSet<>();
5454                     boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5455                     for (Type subType : c.getPermittedSubclasses()) {
5456                         if (subType.isErroneous()) {
5457                             // the type already caused errors, don't produce more potentially misleading errors
5458                             continue;
5459                         }
5460                         boolean isTypeVar = false;
5461                         if (subType.getTag() == TYPEVAR) {
5462                             isTypeVar = true; //error recovery
5463                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5464                                     Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subType)));
5465                         }
5466                         if (subType.tsym.isAnonymous() && !c.isEnum()) {
5467                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5468                         }
5469                         if (permittedTypes.contains(subType.tsym)) {
5470                             DiagnosticPosition pos =
5471                                     env.enclClass.permitting.stream()
5472                                             .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subType.tsym, permittedExpr, true) != null)
5473                                             .limit(2).collect(List.collector()).get(1);
5474                             log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subType)));
5475                         } else {
5476                             permittedTypes.add(subType.tsym);
5477                         }
5478                         if (sealedInUnnamed) {
5479                             if (subType.tsym.packge() != c.packge()) {
5480                                 log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5481                                         Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5482                                 );
5483                             }
5484                         } else if (subType.tsym.packge().modle != c.packge().modle) {
5485                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5486                                     Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5487                             );
5488                         }
5489                         if (subType.tsym == c.type.tsym || types.isSuperType(subType, c.type)) {
5490                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, ((JCClassDecl)env.tree).permitting),
5491                                     Errors.InvalidPermitsClause(
5492                                             subType.tsym == c.type.tsym ?
5493                                                     Fragments.MustNotBeSameClass :
5494                                                     Fragments.MustNotBeSupertype(subType)
5495                                     )
5496                             );
5497                         } else if (!isTypeVar) {
5498                             boolean thisIsASuper = types.directSupertypes(subType)
5499                                                         .stream()
5500                                                         .anyMatch(d -> d.tsym == c);
5501                             if (!thisIsASuper) {
5502                                 if(c.isInterface()) {
5503                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5504                                             Errors.InvalidPermitsClause(Fragments.DoesntImplementSealed(kindName(subType.tsym), subType)));
5505                                 } else {
5506                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5507                                             Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subType)));
5508                                 }
5509                             }
5510                         }
5511                     }
5512                 }
5513 
5514                 List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5515                                                       .stream()
5516                                                       .filter(s -> s.tsym.isSealed())
5517                                                       .map(s -> (ClassSymbol) s.tsym)
5518                                                       .collect(List.collector());
5519 
5520                 if (sealedSupers.isEmpty()) {
5521                     if ((c.flags_field & Flags.NON_SEALED) != 0) {
5522                         boolean hasErrorSuper = false;
5523 
5524                         hasErrorSuper |= types.directSupertypes(c.type)
5525                                               .stream()
5526                                               .anyMatch(s -> s.tsym.kind == Kind.ERR);
5527 
5528                         ClassType ct = (ClassType) c.type;
5529 
5530                         hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5531 
5532                         if (!hasErrorSuper) {
5533                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5534                         }
5535                     }
5536                 } else {
5537                     if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5538                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5539                     }
5540 
5541                     if (!c.type.isCompound()) {
5542                         for (ClassSymbol supertypeSym : sealedSupers) {
5543                             if (!supertypeSym.isPermittedSubclass(c.type.tsym)) {
5544                                 log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5545                             }
5546                         }
5547                         if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5548                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5549                                     c.isInterface() ?
5550                                             Errors.NonSealedOrSealedExpected :
5551                                             Errors.NonSealedSealedOrFinalExpected);
5552                         }
5553                     }
5554                 }
5555 
5556                 env.info.returnResult = null;
5557                 // java.lang.Enum may not be subclassed by a non-enum
5558                 if (st.tsym == syms.enumSym &&
5559                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5560                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5561 
5562                 // Enums may not be extended by source-level classes
5563                 if (st.tsym != null &&
5564                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5565                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5566                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5567                 }
5568 
5569                 if (rs.isSerializable(c.type)) {
5570                     env.info.isSerializable = true;
5571                 }
5572 
5573                 attribClassBody(env, c);
5574 
5575                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5576                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5577                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5578                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5579 
5580                 if (c.isImplicit()) {
5581                     chk.checkHasMain(env.tree.pos(), c);
5582                 }
5583             } finally {
5584                 env.info.returnResult = prevReturnRes;
5585                 log.useSource(prev);
5586                 chk.setLint(prevLint);
5587             }
5588 
5589         }
5590     }
5591 
5592     public void visitImport(JCImport tree) {
5593         // nothing to do
5594     }
5595 
5596     public void visitModuleDef(JCModuleDecl tree) {
5597         tree.sym.completeUsesProvides();
5598         ModuleSymbol msym = tree.sym;
5599         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5600         Lint prevLint = chk.setLint(lint);
5601         try {
5602             chk.checkModuleName(tree);
5603             chk.checkDeprecatedAnnotation(tree, msym);
5604         } finally {
5605             chk.setLint(prevLint);
5606         }
5607     }
5608 
5609     /** Finish the attribution of a class. */
5610     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5611         JCClassDecl tree = (JCClassDecl)env.tree;
5612         Assert.check(c == tree.sym);
5613 
5614         // Validate type parameters, supertype and interfaces.
5615         attribStats(tree.typarams, env);
5616         if (!c.isAnonymous()) {
5617             //already checked if anonymous
5618             chk.validate(tree.typarams, env);
5619             chk.validate(tree.extending, env);
5620             chk.validate(tree.implementing, env);
5621         }
5622 
5623         chk.checkRequiresIdentity(tree, env.info.lint);
5624 
5625         c.markAbstractIfNeeded(types);
5626 
5627         // If this is a non-abstract class, check that it has no abstract
5628         // methods or unimplemented methods of an implemented interface.
5629         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
5630             chk.checkAllDefined(tree.pos(), c);
5631         }
5632 
5633         if ((c.flags() & ANNOTATION) != 0) {
5634             if (tree.implementing.nonEmpty())
5635                 log.error(tree.implementing.head.pos(),
5636                           Errors.CantExtendIntfAnnotation);
5637             if (tree.typarams.nonEmpty()) {
5638                 log.error(tree.typarams.head.pos(),
5639                           Errors.IntfAnnotationCantHaveTypeParams(c));
5640             }
5641 
5642             // If this annotation type has a @Repeatable, validate
5643             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
5644             // If this annotation type has a @Repeatable, validate
5645             if (repeatable != null) {
5646                 // get diagnostic position for error reporting
5647                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
5648                 Assert.checkNonNull(cbPos);
5649 
5650                 chk.validateRepeatable(c, repeatable, cbPos);
5651             }
5652         } else {
5653             // Check that all extended classes and interfaces
5654             // are compatible (i.e. no two define methods with same arguments
5655             // yet different return types).  (JLS 8.4.8.3)
5656             chk.checkCompatibleSupertypes(tree.pos(), c.type);
5657             chk.checkDefaultMethodClashes(tree.pos(), c.type);
5658             chk.checkPotentiallyAmbiguousOverloads(tree, c.type);
5659         }
5660 
5661         // Check that class does not import the same parameterized interface
5662         // with two different argument lists.
5663         chk.checkClassBounds(tree.pos(), c.type);
5664 
5665         tree.type = c.type;
5666 
5667         for (List<JCTypeParameter> l = tree.typarams;
5668              l.nonEmpty(); l = l.tail) {
5669              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
5670         }
5671 
5672         // Check that a generic class doesn't extend Throwable
5673         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
5674             log.error(tree.extending.pos(), Errors.GenericThrowable);
5675 
5676         // Check that all methods which implement some
5677         // method conform to the method they implement.
5678         chk.checkImplementations(tree);
5679 
5680         //check that a resource implementing AutoCloseable cannot throw InterruptedException
5681         checkAutoCloseable(env, tree, false);
5682 
5683         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
5684             // Attribute declaration
5685             attribStat(l.head, env);
5686             // Check that declarations in inner classes are not static (JLS 8.1.2)
5687             // Make an exception for static constants.
5688             if (!allowRecords &&
5689                     c.owner.kind != PCK &&
5690                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
5691                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
5692                 VarSymbol sym = null;
5693                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
5694                 if (sym == null ||
5695                         sym.kind != VAR ||
5696                         sym.getConstValue() == null)
5697                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
5698             }
5699         }
5700 
5701         // Check for proper placement of super()/this() calls.
5702         chk.checkSuperInitCalls(tree);
5703 
5704         // Check for cycles among non-initial constructors.
5705         chk.checkCyclicConstructors(tree);
5706 
5707         // Check for cycles among annotation elements.
5708         chk.checkNonCyclicElements(tree);
5709 
5710         // Check for proper use of serialVersionUID and other
5711         // serialization-related fields and methods
5712         if (env.info.lint.isEnabled(LintCategory.SERIAL)
5713                 && rs.isSerializable(c.type)
5714                 && !c.isAnonymous()) {
5715             chk.checkSerialStructure(tree, c);
5716         }
5717         // Correctly organize the positions of the type annotations
5718         typeAnnotations.organizeTypeAnnotationsBodies(tree);
5719 
5720         // Check type annotations applicability rules
5721         validateTypeAnnotations(tree, false);
5722     }
5723         // where
5724         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
5725         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
5726             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
5727                 if (types.isSameType(al.head.annotationType.type, t))
5728                     return al.head.pos();
5729             }
5730 
5731             return null;
5732         }
5733 
5734     private Type capture(Type type) {
5735         return types.capture(type);
5736     }
5737 
5738     private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
5739         if (type.isErroneous()) {
5740             tree.vartype = make.at(tree.pos()).Erroneous();
5741         } else if (tree.declaredUsingVar()) {
5742             Assert.check(tree.typePos != Position.NOPOS);
5743             tree.vartype = make.at(tree.typePos).Type(type);
5744         } else {
5745             tree.vartype = make.at(tree.pos()).Type(type);
5746         }
5747     }
5748 
5749     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
5750         tree.accept(new TypeAnnotationsValidator(sigOnly));
5751     }
5752     //where
5753     private final class TypeAnnotationsValidator extends TreeScanner {
5754 
5755         private final boolean sigOnly;
5756         public TypeAnnotationsValidator(boolean sigOnly) {
5757             this.sigOnly = sigOnly;
5758         }
5759 
5760         public void visitAnnotation(JCAnnotation tree) {
5761             chk.validateTypeAnnotation(tree, null, false);
5762             super.visitAnnotation(tree);
5763         }
5764         public void visitAnnotatedType(JCAnnotatedType tree) {
5765             if (!tree.underlyingType.type.isErroneous()) {
5766                 super.visitAnnotatedType(tree);
5767             }
5768         }
5769         public void visitTypeParameter(JCTypeParameter tree) {
5770             chk.validateTypeAnnotations(tree.annotations, tree.type.tsym, true);
5771             scan(tree.bounds);
5772             // Don't call super.
5773             // This is needed because above we call validateTypeAnnotation with
5774             // false, which would forbid annotations on type parameters.
5775             // super.visitTypeParameter(tree);
5776         }
5777         public void visitMethodDef(JCMethodDecl tree) {
5778             if (tree.recvparam != null &&
5779                     !tree.recvparam.vartype.type.isErroneous()) {
5780                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
5781             }
5782             if (tree.restype != null && tree.restype.type != null) {
5783                 validateAnnotatedType(tree.restype, tree.restype.type);
5784             }
5785             if (sigOnly) {
5786                 scan(tree.mods);
5787                 scan(tree.restype);
5788                 scan(tree.typarams);
5789                 scan(tree.recvparam);
5790                 scan(tree.params);
5791                 scan(tree.thrown);
5792             } else {
5793                 scan(tree.defaultValue);
5794                 scan(tree.body);
5795             }
5796         }
5797         public void visitVarDef(final JCVariableDecl tree) {
5798             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
5799             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
5800                 validateAnnotatedType(tree.vartype, tree.sym.type);
5801             scan(tree.mods);
5802             scan(tree.vartype);
5803             if (!sigOnly) {
5804                 scan(tree.init);
5805             }
5806         }
5807         public void visitTypeCast(JCTypeCast tree) {
5808             if (tree.clazz != null && tree.clazz.type != null)
5809                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5810             super.visitTypeCast(tree);
5811         }
5812         public void visitTypeTest(JCInstanceOf tree) {
5813             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
5814                 validateAnnotatedType(tree.pattern, tree.pattern.type);
5815             super.visitTypeTest(tree);
5816         }
5817         public void visitNewClass(JCNewClass tree) {
5818             if (tree.clazz != null && tree.clazz.type != null) {
5819                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
5820                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
5821                             tree.clazz.type.tsym);
5822                 }
5823                 if (tree.def != null) {
5824                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
5825                 }
5826 
5827                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5828             }
5829             super.visitNewClass(tree);
5830         }
5831         public void visitNewArray(JCNewArray tree) {
5832             if (tree.elemtype != null && tree.elemtype.type != null) {
5833                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
5834                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
5835                             tree.elemtype.type.tsym);
5836                 }
5837                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
5838             }
5839             super.visitNewArray(tree);
5840         }
5841         public void visitClassDef(JCClassDecl tree) {
5842             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
5843             if (sigOnly) {
5844                 scan(tree.mods);
5845                 scan(tree.typarams);
5846                 scan(tree.extending);
5847                 scan(tree.implementing);
5848             }
5849             for (JCTree member : tree.defs) {
5850                 if (member.hasTag(Tag.CLASSDEF)) {
5851                     continue;
5852                 }
5853                 scan(member);
5854             }
5855         }
5856         public void visitBlock(JCBlock tree) {
5857             if (!sigOnly) {
5858                 scan(tree.stats);
5859             }
5860         }
5861 
5862         /* I would want to model this after
5863          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
5864          * and override visitSelect and visitTypeApply.
5865          * However, we only set the annotated type in the top-level type
5866          * of the symbol.
5867          * Therefore, we need to override each individual location where a type
5868          * can occur.
5869          */
5870         private void validateAnnotatedType(final JCTree errtree, final Type type) {
5871             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
5872 
5873             if (type.isPrimitiveOrVoid()) {
5874                 return;
5875             }
5876 
5877             JCTree enclTr = errtree;
5878             Type enclTy = type;
5879 
5880             boolean repeat = true;
5881             while (repeat) {
5882                 if (enclTr.hasTag(TYPEAPPLY)) {
5883                     List<Type> tyargs = enclTy.getTypeArguments();
5884                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
5885                     if (trargs.length() > 0) {
5886                         // Nothing to do for diamonds
5887                         if (tyargs.length() == trargs.length()) {
5888                             for (int i = 0; i < tyargs.length(); ++i) {
5889                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
5890                             }
5891                         }
5892                         // If the lengths don't match, it's either a diamond
5893                         // or some nested type that redundantly provides
5894                         // type arguments in the tree.
5895                     }
5896 
5897                     // Look at the clazz part of a generic type
5898                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
5899                 }
5900 
5901                 if (enclTr.hasTag(SELECT)) {
5902                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
5903                     if (enclTy != null &&
5904                             !enclTy.hasTag(NONE)) {
5905                         enclTy = enclTy.getEnclosingType();
5906                     }
5907                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
5908                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
5909                     if (enclTy == null || enclTy.hasTag(NONE)) {
5910                         ListBuffer<Attribute.TypeCompound> onlyTypeAnnotationsBuf = new ListBuffer<>();
5911                         for (JCAnnotation an : at.getAnnotations()) {
5912                             if (chk.isTypeAnnotation(an, false)) {
5913                                 onlyTypeAnnotationsBuf.add((Attribute.TypeCompound) an.attribute);
5914                             }
5915                         }
5916                         List<Attribute.TypeCompound> onlyTypeAnnotations = onlyTypeAnnotationsBuf.toList();
5917                         if (!onlyTypeAnnotations.isEmpty()) {
5918                             Fragment annotationFragment = onlyTypeAnnotations.size() == 1 ?
5919                                     Fragments.TypeAnnotation1(onlyTypeAnnotations.head) :
5920                                     Fragments.TypeAnnotation(onlyTypeAnnotations);
5921                             JCDiagnostic.AnnotatedType annotatedType = new JCDiagnostic.AnnotatedType(
5922                                     type.stripMetadata().annotatedType(onlyTypeAnnotations));
5923                             log.error(at.underlyingType.pos(), Errors.TypeAnnotationInadmissible(annotationFragment,
5924                                     type.tsym.owner, annotatedType));
5925                         }
5926                         repeat = false;
5927                     }
5928                     enclTr = at.underlyingType;
5929                     // enclTy doesn't need to be changed
5930                 } else if (enclTr.hasTag(IDENT)) {
5931                     repeat = false;
5932                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
5933                     JCWildcard wc = (JCWildcard) enclTr;
5934                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
5935                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
5936                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
5937                     } else {
5938                         // Nothing to do for UNBOUND
5939                     }
5940                     repeat = false;
5941                 } else if (enclTr.hasTag(TYPEARRAY)) {
5942                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
5943                     validateAnnotatedType(art.getType(), art.elemtype.type);
5944                     repeat = false;
5945                 } else if (enclTr.hasTag(TYPEUNION)) {
5946                     JCTypeUnion ut = (JCTypeUnion) enclTr;
5947                     for (JCTree t : ut.getTypeAlternatives()) {
5948                         validateAnnotatedType(t, t.type);
5949                     }
5950                     repeat = false;
5951                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
5952                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
5953                     for (JCTree t : it.getBounds()) {
5954                         validateAnnotatedType(t, t.type);
5955                     }
5956                     repeat = false;
5957                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
5958                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
5959                     repeat = false;
5960                 } else {
5961                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
5962                             " within: "+ errtree + " with kind: " + errtree.getKind());
5963                 }
5964             }
5965         }
5966 
5967         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
5968                 Symbol sym) {
5969             // Ensure that no declaration annotations are present.
5970             // Note that a tree type might be an AnnotatedType with
5971             // empty annotations, if only declaration annotations were given.
5972             // This method will raise an error for such a type.
5973             for (JCAnnotation ai : annotations) {
5974                 if (!ai.type.isErroneous() &&
5975                         typeAnnotations.annotationTargetType(ai, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
5976                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
5977                 }
5978             }
5979         }
5980     }
5981 
5982     // <editor-fold desc="post-attribution visitor">
5983 
5984     /**
5985      * Handle missing types/symbols in an AST. This routine is useful when
5986      * the compiler has encountered some errors (which might have ended up
5987      * terminating attribution abruptly); if the compiler is used in fail-over
5988      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
5989      * prevents NPE to be propagated during subsequent compilation steps.
5990      */
5991     public void postAttr(JCTree tree) {
5992         new PostAttrAnalyzer().scan(tree);
5993     }
5994 
5995     class PostAttrAnalyzer extends TreeScanner {
5996 
5997         private void initTypeIfNeeded(JCTree that) {
5998             if (that.type == null) {
5999                 if (that.hasTag(METHODDEF)) {
6000                     that.type = dummyMethodType((JCMethodDecl)that);
6001                 } else {
6002                     that.type = syms.unknownType;
6003                 }
6004             }
6005         }
6006 
6007         /* Construct a dummy method type. If we have a method declaration,
6008          * and the declared return type is void, then use that return type
6009          * instead of UNKNOWN to avoid spurious error messages in lambda
6010          * bodies (see:JDK-8041704).
6011          */
6012         private Type dummyMethodType(JCMethodDecl md) {
6013             Type restype = syms.unknownType;
6014             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
6015                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
6016                 if (prim.typetag == VOID)
6017                     restype = syms.voidType;
6018             }
6019             return new MethodType(List.nil(), restype,
6020                                   List.nil(), syms.methodClass);
6021         }
6022         private Type dummyMethodType() {
6023             return dummyMethodType(null);
6024         }
6025 
6026         @Override
6027         public void scan(JCTree tree) {
6028             if (tree == null) return;
6029             if (tree instanceof JCExpression) {
6030                 initTypeIfNeeded(tree);
6031             }
6032             super.scan(tree);
6033         }
6034 
6035         @Override
6036         public void visitIdent(JCIdent that) {
6037             if (that.sym == null) {
6038                 that.sym = syms.unknownSymbol;
6039             }
6040         }
6041 
6042         @Override
6043         public void visitSelect(JCFieldAccess that) {
6044             if (that.sym == null) {
6045                 that.sym = syms.unknownSymbol;
6046             }
6047             super.visitSelect(that);
6048         }
6049 
6050         @Override
6051         public void visitClassDef(JCClassDecl that) {
6052             initTypeIfNeeded(that);
6053             if (that.sym == null) {
6054                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
6055             }
6056             super.visitClassDef(that);
6057         }
6058 
6059         @Override
6060         public void visitMethodDef(JCMethodDecl that) {
6061             initTypeIfNeeded(that);
6062             if (that.sym == null) {
6063                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
6064             }
6065             super.visitMethodDef(that);
6066         }
6067 
6068         @Override
6069         public void visitVarDef(JCVariableDecl that) {
6070             initTypeIfNeeded(that);
6071             if (that.sym == null) {
6072                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
6073                 that.sym.adr = 0;
6074             }
6075             if (that.vartype == null) {
6076                 that.vartype = make.at(Position.NOPOS).Erroneous();
6077             }
6078             super.visitVarDef(that);
6079         }
6080 
6081         @Override
6082         public void visitBindingPattern(JCBindingPattern that) {
6083             initTypeIfNeeded(that);
6084             initTypeIfNeeded(that.var);
6085             if (that.var.sym == null) {
6086                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6087                 that.var.sym.adr = 0;
6088             }
6089             super.visitBindingPattern(that);
6090         }
6091 
6092         @Override
6093         public void visitRecordPattern(JCRecordPattern that) {
6094             initTypeIfNeeded(that);
6095             if (that.record == null) {
6096                 that.record = new ClassSymbol(0, TreeInfo.name(that.deconstructor),
6097                                               that.type, syms.noSymbol);
6098             }
6099             if (that.fullComponentTypes == null) {
6100                 that.fullComponentTypes = List.nil();
6101             }
6102             super.visitRecordPattern(that);
6103         }
6104 
6105         @Override
6106         public void visitNewClass(JCNewClass that) {
6107             if (that.constructor == null) {
6108                 that.constructor = new MethodSymbol(0, names.init,
6109                         dummyMethodType(), syms.noSymbol);
6110             }
6111             if (that.constructorType == null) {
6112                 that.constructorType = syms.unknownType;
6113             }
6114             super.visitNewClass(that);
6115         }
6116 
6117         @Override
6118         public void visitAssignop(JCAssignOp that) {
6119             if (that.operator == null) {
6120                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6121                         -1, syms.noSymbol);
6122             }
6123             super.visitAssignop(that);
6124         }
6125 
6126         @Override
6127         public void visitBinary(JCBinary that) {
6128             if (that.operator == null) {
6129                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6130                         -1, syms.noSymbol);
6131             }
6132             super.visitBinary(that);
6133         }
6134 
6135         @Override
6136         public void visitUnary(JCUnary that) {
6137             if (that.operator == null) {
6138                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6139                         -1, syms.noSymbol);
6140             }
6141             super.visitUnary(that);
6142         }
6143 
6144         @Override
6145         public void visitReference(JCMemberReference that) {
6146             super.visitReference(that);
6147             if (that.sym == null) {
6148                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6149                         syms.noSymbol);
6150             }
6151         }
6152     }
6153     // </editor-fold>
6154 
6155     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6156         new TreeScanner() {
6157             Symbol packge = pkg;
6158             @Override
6159             public void visitIdent(JCIdent that) {
6160                 that.sym = packge;
6161             }
6162 
6163             @Override
6164             public void visitSelect(JCFieldAccess that) {
6165                 that.sym = packge;
6166                 packge = packge.owner;
6167                 super.visitSelect(that);
6168             }
6169         }.scan(pid);
6170     }
6171 
6172 }