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.LambdaExpressionTree.BodyKind;
  40 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
  41 import com.sun.source.tree.MemberSelectTree;
  42 import com.sun.source.tree.TreeVisitor;
  43 import com.sun.source.util.SimpleTreeVisitor;
  44 import com.sun.tools.javac.code.*;
  45 import com.sun.tools.javac.code.Lint.LintCategory;
  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.Attr.ResultInfo;
  53 import com.sun.tools.javac.comp.Check.CheckContext;
  54 import com.sun.tools.javac.comp.Check.NestedCheckContext;
  55 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
  56 import com.sun.tools.javac.comp.DeferredAttr.LambdaReturnScanner;
  57 import com.sun.tools.javac.comp.MatchBindingsComputer.MatchBindings;
  58 import com.sun.tools.javac.jvm.*;
  59 
  60 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
  61 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
  62 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
  63 
  64 import com.sun.tools.javac.resources.CompilerProperties.Errors;
  65 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  66 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings;
  67 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
  68 import com.sun.tools.javac.tree.*;
  69 import com.sun.tools.javac.tree.JCTree.*;
  70 import com.sun.tools.javac.tree.JCTree.JCLambda.ParameterKind;
  71 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
  72 import com.sun.tools.javac.util.*;
  73 import com.sun.tools.javac.util.DefinedBy.Api;
  74 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  75 import com.sun.tools.javac.util.JCDiagnostic.Error;
  76 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
  77 import com.sun.tools.javac.util.JCDiagnostic.Warning;
  78 import com.sun.tools.javac.util.List;
  79 
  80 import static com.sun.tools.javac.code.Flags.*;
  81 import static com.sun.tools.javac.code.Flags.ANNOTATION;
  82 import static com.sun.tools.javac.code.Flags.BLOCK;
  83 import static com.sun.tools.javac.code.Kinds.*;
  84 import static com.sun.tools.javac.code.Kinds.Kind.*;
  85 import static com.sun.tools.javac.code.TypeTag.*;
  86 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
  87 import static com.sun.tools.javac.tree.JCTree.Tag.*;
  88 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
  89 
  90 /** This is the main context-dependent analysis phase in GJC. It
  91  *  encompasses name resolution, type checking and constant folding as
  92  *  subtasks. Some subtasks involve auxiliary classes.
  93  *  @see Check
  94  *  @see Resolve
  95  *  @see ConstFold
  96  *  @see Infer
  97  *
  98  *  <p><b>This is NOT part of any supported API.
  99  *  If you write code that depends on this, you do so at your own risk.
 100  *  This code and its internal interfaces are subject to change or
 101  *  deletion without notice.</b>
 102  */
 103 public class Attr extends JCTree.Visitor {
 104     protected static final Context.Key<Attr> attrKey = new Context.Key<>();
 105 
 106     final Names names;
 107     final Log log;
 108     final Symtab syms;
 109     final Resolve rs;
 110     final Operators operators;
 111     final Infer infer;
 112     final Analyzer analyzer;
 113     final DeferredAttr deferredAttr;
 114     final Check chk;
 115     final Flow flow;
 116     final MemberEnter memberEnter;
 117     final TypeEnter typeEnter;
 118     final TreeMaker make;
 119     final ConstFold cfolder;
 120     final Enter enter;
 121     final Target target;
 122     final Types types;
 123     final Preview preview;
 124     final JCDiagnostic.Factory diags;
 125     final TypeAnnotations typeAnnotations;
 126     final DeferredLintHandler deferredLintHandler;
 127     final TypeEnvs typeEnvs;
 128     final Dependencies dependencies;
 129     final Annotate annotate;
 130     final ArgumentAttr argumentAttr;
 131     final MatchBindingsComputer matchBindingsComputer;
 132     final AttrRecover attrRecover;
 133 
 134     public static Attr instance(Context context) {
 135         Attr instance = context.get(attrKey);
 136         if (instance == null)
 137             instance = new Attr(context);
 138         return instance;
 139     }
 140 
 141     @SuppressWarnings("this-escape")
 142     protected Attr(Context context) {
 143         context.put(attrKey, this);
 144 
 145         names = Names.instance(context);
 146         log = Log.instance(context);
 147         syms = Symtab.instance(context);
 148         rs = Resolve.instance(context);
 149         operators = Operators.instance(context);
 150         chk = Check.instance(context);
 151         flow = Flow.instance(context);
 152         memberEnter = MemberEnter.instance(context);
 153         typeEnter = TypeEnter.instance(context);
 154         make = TreeMaker.instance(context);
 155         enter = Enter.instance(context);
 156         infer = Infer.instance(context);
 157         analyzer = Analyzer.instance(context);
 158         deferredAttr = DeferredAttr.instance(context);
 159         cfolder = ConstFold.instance(context);
 160         target = Target.instance(context);
 161         types = Types.instance(context);
 162         preview = Preview.instance(context);
 163         diags = JCDiagnostic.Factory.instance(context);
 164         annotate = Annotate.instance(context);
 165         typeAnnotations = TypeAnnotations.instance(context);
 166         deferredLintHandler = DeferredLintHandler.instance(context);
 167         typeEnvs = TypeEnvs.instance(context);
 168         dependencies = Dependencies.instance(context);
 169         argumentAttr = ArgumentAttr.instance(context);
 170         matchBindingsComputer = MatchBindingsComputer.instance(context);
 171         attrRecover = AttrRecover.instance(context);
 172 
 173         Options options = Options.instance(context);
 174 
 175         Source source = Source.instance(context);
 176         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 177         allowRecords = Feature.RECORDS.allowedInSource(source);
 178         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 179                              Feature.PATTERN_SWITCH.allowedInSource(source);
 180         allowUnconditionalPatternsInstanceOf =
 181                              Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 182         sourceName = source.name;
 183         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 184 
 185         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 186         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 187         unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
 188         methodAttrInfo = new MethodAttrInfo();
 189         unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
 190         unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
 191         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
 192         initBlockType = new MethodType(List.nil(), syms.voidType, List.nil(), syms.methodClass);
 193     }
 194 
 195     /** Switch: reifiable types in instanceof enabled?
 196      */
 197     boolean allowReifiableTypesInInstanceof;
 198 
 199     /** Are records allowed
 200      */
 201     private final boolean allowRecords;
 202 
 203     /** Are patterns in switch allowed
 204      */
 205     private final boolean allowPatternSwitch;
 206 
 207     /** Are unconditional patterns in instanceof allowed
 208      */
 209     private final boolean allowUnconditionalPatternsInstanceOf;
 210 
 211     /**
 212      * Switch: warn about use of variable before declaration?
 213      * RFE: 6425594
 214      */
 215     boolean useBeforeDeclarationWarning;
 216 
 217     /**
 218      * Switch: name of source level; used for error reporting.
 219      */
 220     String sourceName;
 221 
 222     /** Check kind and type of given tree against protokind and prototype.
 223      *  If check succeeds, store type in tree and return it.
 224      *  If check fails, store errType in tree and return it.
 225      *  No checks are performed if the prototype is a method type.
 226      *  It is not necessary in this case since we know that kind and type
 227      *  are correct.
 228      *
 229      *  @param tree     The tree whose kind and type is checked
 230      *  @param found    The computed type of the tree
 231      *  @param ownkind  The computed kind of the tree
 232      *  @param resultInfo  The expected result of the tree
 233      */
 234     Type check(final JCTree tree,
 235                final Type found,
 236                final KindSelector ownkind,
 237                final ResultInfo resultInfo) {
 238         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 239         Type owntype;
 240         boolean shouldCheck = !found.hasTag(ERROR) &&
 241                 !resultInfo.pt.hasTag(METHOD) &&
 242                 !resultInfo.pt.hasTag(FORALL);
 243         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 244             log.error(tree.pos(),
 245                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 246                                             ownkind.kindNames()));
 247             owntype = types.createErrorType(found);
 248         } else if (inferenceContext.free(found)) {
 249             //delay the check if there are inference variables in the found type
 250             //this means we are dealing with a partially inferred poly expression
 251             owntype = shouldCheck ? resultInfo.pt : found;
 252             if (resultInfo.checkMode.installPostInferenceHook()) {
 253                 inferenceContext.addFreeTypeListener(List.of(found),
 254                         instantiatedContext -> {
 255                             ResultInfo pendingResult =
 256                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 257                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 258                         });
 259             }
 260         } else {
 261             owntype = shouldCheck ?
 262             resultInfo.check(tree, found) :
 263             found;
 264         }
 265         if (resultInfo.checkMode.updateTreeType()) {
 266             tree.type = owntype;
 267         }
 268         return owntype;
 269     }
 270 
 271     /** Is given blank final variable assignable, i.e. in a scope where it
 272      *  may be assigned to even though it is final?
 273      *  @param v      The blank final variable.
 274      *  @param env    The current environment.
 275      */
 276     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 277         Symbol owner = env.info.scope.owner;
 278            // owner refers to the innermost variable, method or
 279            // initializer block declaration at this point.
 280         boolean isAssignable =
 281             v.owner == owner
 282             ||
 283             ((owner.name == names.init ||    // i.e. we are in a constructor
 284               owner.kind == VAR ||           // i.e. we are in a variable initializer
 285               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 286              &&
 287              v.owner == owner.owner
 288              &&
 289              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 290         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 291         return isAssignable & !insideCompactConstructor;
 292     }
 293 
 294     /** Check that variable can be assigned to.
 295      *  @param pos    The current source code position.
 296      *  @param v      The assigned variable
 297      *  @param base   If the variable is referred to in a Select, the part
 298      *                to the left of the `.', null otherwise.
 299      *  @param env    The current environment.
 300      */
 301     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 302         if (v.name == names._this) {
 303             log.error(pos, Errors.CantAssignValToThis);
 304             return;
 305         }
 306         if ((v.flags() & FINAL) != 0 &&
 307             ((v.flags() & HASINIT) != 0
 308              ||
 309              !((base == null ||
 310                TreeInfo.isThisQualifier(base)) &&
 311                isAssignableAsBlankFinal(v, env)))) {
 312             if (v.isResourceVariable()) { //TWR resource
 313                 log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
 314             } else {
 315                 log.error(pos, Errors.CantAssignValToVar(Flags.toSource(v.flags() & (STATIC | FINAL)), v));
 316             }
 317             return;
 318         }
 319 
 320         // Check instance field assignments that appear in constructor prologues
 321         if (rs.isEarlyReference(env, base, v)) {
 322 
 323             // Field may not be inherited from a superclass
 324             if (v.owner != env.enclClass.sym) {
 325                 log.error(pos, Errors.CantRefBeforeCtorCalled(v));
 326                 return;
 327             }
 328 
 329             // Field may not have an initializer
 330             if ((v.flags() & HASINIT) != 0) {
 331                 log.error(pos, Errors.CantAssignInitializedBeforeCtorCalled(v));
 332                 return;
 333             }
 334         }
 335     }
 336 
 337     /** Does tree represent a static reference to an identifier?
 338      *  It is assumed that tree is either a SELECT or an IDENT.
 339      *  We have to weed out selects from non-type names here.
 340      *  @param tree    The candidate tree.
 341      */
 342     boolean isStaticReference(JCTree tree) {
 343         if (tree.hasTag(SELECT)) {
 344             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 345             if (lsym == null || lsym.kind != TYP) {
 346                 return false;
 347             }
 348         }
 349         return true;
 350     }
 351 
 352     /** Is this symbol a type?
 353      */
 354     static boolean isType(Symbol sym) {
 355         return sym != null && sym.kind == TYP;
 356     }
 357 
 358     /** Attribute a parsed identifier.
 359      * @param tree Parsed identifier name
 360      * @param topLevel The toplevel to use
 361      */
 362     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 363         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 364         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 365                                            syms.errSymbol.name,
 366                                            null, null, null, null);
 367         localEnv.enclClass.sym = syms.errSymbol;
 368         return attribIdent(tree, localEnv);
 369     }
 370 
 371     /** Attribute a parsed identifier.
 372      * @param tree Parsed identifier name
 373      * @param env The env to use
 374      */
 375     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 376         return tree.accept(identAttributer, env);
 377     }
 378     // where
 379         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 380         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 381             @Override @DefinedBy(Api.COMPILER_TREE)
 382             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 383                 Symbol site = visit(node.getExpression(), env);
 384                 if (site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 385                     return site;
 386                 Name name = (Name)node.getIdentifier();
 387                 if (site.kind == PCK) {
 388                     env.toplevel.packge = (PackageSymbol)site;
 389                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 390                             KindSelector.TYP_PCK);
 391                 } else {
 392                     env.enclClass.sym = (ClassSymbol)site;
 393                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 394                 }
 395             }
 396 
 397             @Override @DefinedBy(Api.COMPILER_TREE)
 398             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 399                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 400             }
 401         }
 402 
 403     public Type coerce(Type etype, Type ttype) {
 404         return cfolder.coerce(etype, ttype);
 405     }
 406 
 407     public Type attribType(JCTree node, TypeSymbol sym) {
 408         Env<AttrContext> env = typeEnvs.get(sym);
 409         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 410         return attribTree(node, localEnv, unknownTypeInfo);
 411     }
 412 
 413     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 414         // Attribute qualifying package or class.
 415         JCFieldAccess s = tree.qualid;
 416         return attribTree(s.selected, env,
 417                           new ResultInfo(tree.staticImport ?
 418                                          KindSelector.TYP : KindSelector.TYP_PCK,
 419                        Type.noType));
 420     }
 421 
 422     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 423         return attribToTree(expr, env, tree, unknownExprInfo);
 424     }
 425 
 426     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 427         return attribToTree(stmt, env, tree, statInfo);
 428     }
 429 
 430     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 431         breakTree = tree;
 432         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 433         try {
 434             deferredAttr.attribSpeculative(root, env, resultInfo,
 435                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 436                     argumentAttr.withLocalCacheContext());
 437             attrRecover.doRecovery();
 438         } catch (BreakAttr b) {
 439             return b.env;
 440         } catch (AssertionError ae) {
 441             if (ae.getCause() instanceof BreakAttr breakAttr) {
 442                 return breakAttr.env;
 443             } else {
 444                 throw ae;
 445             }
 446         } finally {
 447             breakTree = null;
 448             log.useSource(prev);
 449         }
 450         return env;
 451     }
 452 
 453     public <R> R runWithAttributedMethod(Env<AttrContext> env, JCMethodDecl tree, Function<JCBlock, R> attributedAction) {
 454         JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 455         try {
 456             JCBlock dupTree = (JCBlock)deferredAttr.attribSpeculative(tree.body, env, statInfo,
 457                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 458                     argumentAttr.withLocalCacheContext());
 459             return attributedAction.apply(dupTree);
 460         } finally {
 461             attrRecover.doRecovery();
 462             log.useSource(prevSource);
 463         }
 464     }
 465 
 466     private JCTree breakTree = null;
 467 
 468     private static class BreakAttr extends RuntimeException {
 469         static final long serialVersionUID = -6924771130405446405L;
 470         private transient Env<AttrContext> env;
 471         private BreakAttr(Env<AttrContext> env) {
 472             this.env = env;
 473         }
 474     }
 475 
 476     /**
 477      * Mode controlling behavior of Attr.Check
 478      */
 479     enum CheckMode {
 480 
 481         NORMAL,
 482 
 483         /**
 484          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 485          * that the captured var cache in {@code InferenceContext} will be used in read-only
 486          * mode when performing inference checks.
 487          */
 488         NO_TREE_UPDATE {
 489             @Override
 490             public boolean updateTreeType() {
 491                 return false;
 492             }
 493         },
 494         /**
 495          * Mode signalling that caller will manage free types in tree decorations.
 496          */
 497         NO_INFERENCE_HOOK {
 498             @Override
 499             public boolean installPostInferenceHook() {
 500                 return false;
 501             }
 502         };
 503 
 504         public boolean updateTreeType() {
 505             return true;
 506         }
 507         public boolean installPostInferenceHook() {
 508             return true;
 509         }
 510     }
 511 
 512 
 513     class ResultInfo {
 514         final KindSelector pkind;
 515         final Type pt;
 516         final CheckContext checkContext;
 517         final CheckMode checkMode;
 518 
 519         ResultInfo(KindSelector pkind, Type pt) {
 520             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 521         }
 522 
 523         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 524             this(pkind, pt, chk.basicHandler, checkMode);
 525         }
 526 
 527         protected ResultInfo(KindSelector pkind,
 528                              Type pt, CheckContext checkContext) {
 529             this(pkind, pt, checkContext, CheckMode.NORMAL);
 530         }
 531 
 532         protected ResultInfo(KindSelector pkind,
 533                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 534             this.pkind = pkind;
 535             this.pt = pt;
 536             this.checkContext = checkContext;
 537             this.checkMode = checkMode;
 538         }
 539 
 540         /**
 541          * Should {@link Attr#attribTree} use the {@code ArgumentAttr} visitor instead of this one?
 542          * @param tree The tree to be type-checked.
 543          * @return true if {@code ArgumentAttr} should be used.
 544          */
 545         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 546 
 547         protected Type check(final DiagnosticPosition pos, final Type found) {
 548             return chk.checkType(pos, found, pt, checkContext);
 549         }
 550 
 551         protected ResultInfo dup(Type newPt) {
 552             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 553         }
 554 
 555         protected ResultInfo dup(CheckContext newContext) {
 556             return new ResultInfo(pkind, pt, newContext, checkMode);
 557         }
 558 
 559         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 560             return new ResultInfo(pkind, newPt, newContext, checkMode);
 561         }
 562 
 563         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 564             return new ResultInfo(pkind, newPt, newContext, newMode);
 565         }
 566 
 567         protected ResultInfo dup(CheckMode newMode) {
 568             return new ResultInfo(pkind, pt, checkContext, newMode);
 569         }
 570 
 571         @Override
 572         public String toString() {
 573             if (pt != null) {
 574                 return pt.toString();
 575             } else {
 576                 return "";
 577             }
 578         }
 579     }
 580 
 581     class MethodAttrInfo extends ResultInfo {
 582         public MethodAttrInfo() {
 583             this(chk.basicHandler);
 584         }
 585 
 586         public MethodAttrInfo(CheckContext checkContext) {
 587             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 588         }
 589 
 590         @Override
 591         protected boolean needsArgumentAttr(JCTree tree) {
 592             return true;
 593         }
 594 
 595         protected ResultInfo dup(Type newPt) {
 596             throw new IllegalStateException();
 597         }
 598 
 599         protected ResultInfo dup(CheckContext newContext) {
 600             return new MethodAttrInfo(newContext);
 601         }
 602 
 603         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 604             throw new IllegalStateException();
 605         }
 606 
 607         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 608             throw new IllegalStateException();
 609         }
 610 
 611         protected ResultInfo dup(CheckMode newMode) {
 612             throw new IllegalStateException();
 613         }
 614     }
 615 
 616     class RecoveryInfo extends ResultInfo {
 617 
 618         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 619             this(deferredAttrContext, Type.recoveryType);
 620         }
 621 
 622         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 623             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 624                 @Override
 625                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 626                     return deferredAttrContext;
 627                 }
 628                 @Override
 629                 public boolean compatible(Type found, Type req, Warner warn) {
 630                     return true;
 631                 }
 632                 @Override
 633                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 634                     boolean needsReport = pt == Type.recoveryType ||
 635                             (details.getDiagnosticPosition() != null &&
 636                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 637                     if (needsReport) {
 638                         chk.basicHandler.report(pos, details);
 639                     }
 640                 }
 641             });
 642         }
 643     }
 644 
 645     final ResultInfo statInfo;
 646     final ResultInfo varAssignmentInfo;
 647     final ResultInfo methodAttrInfo;
 648     final ResultInfo unknownExprInfo;
 649     final ResultInfo unknownTypeInfo;
 650     final ResultInfo unknownTypeExprInfo;
 651     final ResultInfo recoveryInfo;
 652     final MethodType initBlockType;
 653 
 654     Type pt() {
 655         return resultInfo.pt;
 656     }
 657 
 658     KindSelector pkind() {
 659         return resultInfo.pkind;
 660     }
 661 
 662 /* ************************************************************************
 663  * Visitor methods
 664  *************************************************************************/
 665 
 666     /** Visitor argument: the current environment.
 667      */
 668     Env<AttrContext> env;
 669 
 670     /** Visitor argument: the currently expected attribution result.
 671      */
 672     ResultInfo resultInfo;
 673 
 674     /** Visitor result: the computed type.
 675      */
 676     Type result;
 677 
 678     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 679 
 680     /** Visitor method: attribute a tree, catching any completion failure
 681      *  exceptions. Return the tree's type.
 682      *
 683      *  @param tree    The tree to be visited.
 684      *  @param env     The environment visitor argument.
 685      *  @param resultInfo   The result info visitor argument.
 686      */
 687     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 688         Env<AttrContext> prevEnv = this.env;
 689         ResultInfo prevResult = this.resultInfo;
 690         try {
 691             this.env = env;
 692             this.resultInfo = resultInfo;
 693             if (resultInfo.needsArgumentAttr(tree)) {
 694                 result = argumentAttr.attribArg(tree, env);
 695             } else {
 696                 tree.accept(this);
 697             }
 698             matchBindings = matchBindingsComputer.finishBindings(tree,
 699                                                                  matchBindings);
 700             if (tree == breakTree &&
 701                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 702                 breakTreeFound(copyEnv(env));
 703             }
 704             return result;
 705         } catch (CompletionFailure ex) {
 706             tree.type = syms.errType;
 707             return chk.completionError(tree.pos(), ex);
 708         } finally {
 709             this.env = prevEnv;
 710             this.resultInfo = prevResult;
 711         }
 712     }
 713 
 714     protected void breakTreeFound(Env<AttrContext> env) {
 715         throw new BreakAttr(env);
 716     }
 717 
 718     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 719         Env<AttrContext> newEnv =
 720                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 721         if (newEnv.outer != null) {
 722             newEnv.outer = copyEnv(newEnv.outer);
 723         }
 724         return newEnv;
 725     }
 726 
 727     WriteableScope copyScope(WriteableScope sc) {
 728         WriteableScope newScope = WriteableScope.create(sc.owner);
 729         List<Symbol> elemsList = List.nil();
 730         for (Symbol sym : sc.getSymbols()) {
 731             elemsList = elemsList.prepend(sym);
 732         }
 733         for (Symbol s : elemsList) {
 734             newScope.enter(s);
 735         }
 736         return newScope;
 737     }
 738 
 739     /** Derived visitor method: attribute an expression tree.
 740      */
 741     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 742         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 743     }
 744 
 745     /** Derived visitor method: attribute an expression tree with
 746      *  no constraints on the computed type.
 747      */
 748     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 749         return attribTree(tree, env, unknownExprInfo);
 750     }
 751 
 752     /** Derived visitor method: attribute a type tree.
 753      */
 754     public Type attribType(JCTree tree, Env<AttrContext> env) {
 755         Type result = attribType(tree, env, Type.noType);
 756         return result;
 757     }
 758 
 759     /** Derived visitor method: attribute a type tree.
 760      */
 761     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 762         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 763         return result;
 764     }
 765 
 766     /** Derived visitor method: attribute a statement or definition tree.
 767      */
 768     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 769         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 770         Type result = attribTree(tree, env, statInfo);
 771         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 772         attrRecover.doRecovery();
 773         return result;
 774     }
 775 
 776     /** Attribute a list of expressions, returning a list of types.
 777      */
 778     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 779         ListBuffer<Type> ts = new ListBuffer<>();
 780         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 781             ts.append(attribExpr(l.head, env, pt));
 782         return ts.toList();
 783     }
 784 
 785     /** Attribute a list of statements, returning nothing.
 786      */
 787     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 788         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 789             attribStat(l.head, env);
 790     }
 791 
 792     /** Attribute the arguments in a method call, returning the method kind.
 793      */
 794     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 795         KindSelector kind = initialKind;
 796         for (JCExpression arg : trees) {
 797             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 798             if (argtype.hasTag(DEFERRED)) {
 799                 kind = KindSelector.of(KindSelector.POLY, kind);
 800             }
 801             argtypes.append(argtype);
 802         }
 803         return kind;
 804     }
 805 
 806     /** Attribute a type argument list, returning a list of types.
 807      *  Caller is responsible for calling checkRefTypes.
 808      */
 809     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 810         ListBuffer<Type> argtypes = new ListBuffer<>();
 811         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 812             argtypes.append(attribType(l.head, env));
 813         return argtypes.toList();
 814     }
 815 
 816     /** Attribute a type argument list, returning a list of types.
 817      *  Check that all the types are references.
 818      */
 819     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 820         List<Type> types = attribAnyTypes(trees, env);
 821         return chk.checkRefTypes(trees, types);
 822     }
 823 
 824     /**
 825      * Attribute type variables (of generic classes or methods).
 826      * Compound types are attributed later in attribBounds.
 827      * @param typarams the type variables to enter
 828      * @param env      the current environment
 829      */
 830     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 831         for (JCTypeParameter tvar : typarams) {
 832             TypeVar a = (TypeVar)tvar.type;
 833             a.tsym.flags_field |= UNATTRIBUTED;
 834             a.setUpperBound(Type.noType);
 835             if (!tvar.bounds.isEmpty()) {
 836                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 837                 for (JCExpression bound : tvar.bounds.tail)
 838                     bounds = bounds.prepend(attribType(bound, env));
 839                 types.setBounds(a, bounds.reverse());
 840             } else {
 841                 // if no bounds are given, assume a single bound of
 842                 // java.lang.Object.
 843                 types.setBounds(a, List.of(syms.objectType));
 844             }
 845             a.tsym.flags_field &= ~UNATTRIBUTED;
 846         }
 847         if (checkCyclic) {
 848             for (JCTypeParameter tvar : typarams) {
 849                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 850             }
 851         }
 852     }
 853 
 854     /**
 855      * Attribute the type references in a list of annotations.
 856      */
 857     void attribAnnotationTypes(List<JCAnnotation> annotations,
 858                                Env<AttrContext> env) {
 859         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 860             JCAnnotation a = al.head;
 861             attribType(a.annotationType, env);
 862         }
 863     }
 864 
 865     /**
 866      * Attribute a "lazy constant value".
 867      *  @param env         The env for the const value
 868      *  @param variable    The initializer for the const value
 869      *  @param type        The expected type, or null
 870      *  @see VarSymbol#setLazyConstValue
 871      */
 872     public Object attribLazyConstantValue(Env<AttrContext> env,
 873                                       Env<AttrContext> enclosingEnv,
 874                                       JCVariableDecl variable,
 875                                       Type type) {
 876         deferredLintHandler.push(variable);
 877         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 878         try {
 879             doQueueScanTreeAndTypeAnnotateForVarInit(variable, enclosingEnv);
 880             Type itype = attribExpr(variable.init, env, type);
 881             if (variable.isImplicitlyTyped()) {
 882                 //fixup local variable type
 883                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 884             }
 885             if (itype.constValue() != null) {
 886                 return coerce(itype, type).constValue();
 887             } else {
 888                 return null;
 889             }
 890         } finally {
 891             log.useSource(prevSource);
 892             deferredLintHandler.pop();
 893         }
 894     }
 895 
 896     /** Attribute type reference in an `extends', `implements', or 'permits' clause.
 897      *  Supertypes of anonymous inner classes are usually already attributed.
 898      *
 899      *  @param tree              The tree making up the type reference.
 900      *  @param env               The environment current at the reference.
 901      *  @param classExpected     true if only a class is expected here.
 902      *  @param interfaceExpected true if only an interface is expected here.
 903      */
 904     Type attribBase(JCTree tree,
 905                     Env<AttrContext> env,
 906                     boolean classExpected,
 907                     boolean interfaceExpected,
 908                     boolean checkExtensible) {
 909         Type t = tree.type != null ?
 910             tree.type :
 911             attribType(tree, env);
 912         try {
 913             return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 914         } catch (CompletionFailure ex) {
 915             chk.completionError(tree.pos(), ex);
 916             return t;
 917         }
 918     }
 919     Type checkBase(Type t,
 920                    JCTree tree,
 921                    Env<AttrContext> env,
 922                    boolean classExpected,
 923                    boolean interfaceExpected,
 924                    boolean checkExtensible) {
 925         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 926                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 927         if (t.tsym.isAnonymous()) {
 928             log.error(pos, Errors.CantInheritFromAnon);
 929             return types.createErrorType(t);
 930         }
 931         if (t.isErroneous())
 932             return t;
 933         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 934             // check that type variable is already visible
 935             if (t.getUpperBound() == null) {
 936                 log.error(pos, Errors.IllegalForwardRef);
 937                 return types.createErrorType(t);
 938             }
 939         } else {
 940             t = chk.checkClassType(pos, t, checkExtensible);
 941         }
 942         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 943             log.error(pos, Errors.IntfExpectedHere);
 944             // return errType is necessary since otherwise there might
 945             // be undetected cycles which cause attribution to loop
 946             return types.createErrorType(t);
 947         } else if (checkExtensible &&
 948                    classExpected &&
 949                    (t.tsym.flags() & INTERFACE) != 0) {
 950             log.error(pos, Errors.NoIntfExpectedHere);
 951             return types.createErrorType(t);
 952         }
 953         if (checkExtensible &&
 954             ((t.tsym.flags() & FINAL) != 0)) {
 955             log.error(pos,
 956                       Errors.CantInheritFromFinal(t.tsym));
 957         }
 958         chk.checkNonCyclic(pos, t);
 959         return t;
 960     }
 961 
 962     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 963         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 964         id.type = env.info.scope.owner.enclClass().type;
 965         id.sym = env.info.scope.owner.enclClass();
 966         return id.type;
 967     }
 968 
 969     public void visitClassDef(JCClassDecl tree) {
 970         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 971                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 972                         argumentAttr.withLocalCacheContext() : null);
 973         boolean ctorProloguePrev = env.info.ctorPrologue;
 974         try {
 975             // Local and anonymous classes have not been entered yet, so we need to
 976             // do it now.
 977             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 978                 enter.classEnter(tree, env);
 979             } else {
 980                 // If this class declaration is part of a class level annotation,
 981                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 982                 // order to simplify later steps and allow for sensible error
 983                 // messages.
 984                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 985                     enter.classEnter(tree, env);
 986             }
 987 
 988             ClassSymbol c = tree.sym;
 989             if (c == null) {
 990                 // exit in case something drastic went wrong during enter.
 991                 result = null;
 992             } else {
 993                 // make sure class has been completed:
 994                 c.complete();
 995 
 996                 // If a class declaration appears in a constructor prologue,
 997                 // that means it's either a local class or an anonymous class.
 998                 // Either way, there is no immediately enclosing instance.
 999                 if (ctorProloguePrev) {
1000                     c.flags_field |= NOOUTERTHIS;
1001                 }
1002                 attribClass(tree.pos(), c);
1003                 result = tree.type = c.type;
1004             }
1005         } finally {
1006             localCacheContext.ifPresent(LocalCacheContext::leave);
1007             env.info.ctorPrologue = ctorProloguePrev;
1008         }
1009     }
1010 
1011     public void visitMethodDef(JCMethodDecl tree) {
1012         MethodSymbol m = tree.sym;
1013         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
1014 
1015         Lint lint = env.info.lint.augment(m);
1016         Lint prevLint = chk.setLint(lint);
1017         boolean ctorProloguePrev = env.info.ctorPrologue;
1018         Assert.check(!env.info.ctorPrologue);
1019         MethodSymbol prevMethod = chk.setMethod(m);
1020         try {
1021             deferredLintHandler.flush(tree, lint);
1022             chk.checkDeprecatedAnnotation(tree.pos(), m);
1023 
1024 
1025             // Create a new environment with local scope
1026             // for attributing the method.
1027             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
1028             localEnv.info.lint = lint;
1029 
1030             attribStats(tree.typarams, localEnv);
1031 
1032             // If we override any other methods, check that we do so properly.
1033             // JLS ???
1034             if (m.isStatic()) {
1035                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1036             } else {
1037                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1038             }
1039             chk.checkOverride(env, tree, m);
1040 
1041             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1042                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1043             }
1044 
1045             // Enter all type parameters into the local method scope.
1046             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1047                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1048 
1049             ClassSymbol owner = env.enclClass.sym;
1050             if ((owner.flags() & ANNOTATION) != 0 &&
1051                     (tree.params.nonEmpty() ||
1052                     tree.recvparam != null))
1053                 log.error(tree.params.nonEmpty() ?
1054                         tree.params.head.pos() :
1055                         tree.recvparam.pos(),
1056                         Errors.IntfAnnotationMembersCantHaveParams);
1057 
1058             // Attribute all value parameters.
1059             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1060                 attribStat(l.head, localEnv);
1061             }
1062 
1063             chk.checkVarargsMethodDecl(localEnv, tree);
1064 
1065             // Check that type parameters are well-formed.
1066             chk.validate(tree.typarams, localEnv);
1067 
1068             // Check that result type is well-formed.
1069             if (tree.restype != null && !tree.restype.type.hasTag(VOID)) {
1070                 chk.validate(tree.restype, localEnv);
1071             }
1072             chk.checkRequiresIdentity(tree, env.info.lint);
1073 
1074             // Check that receiver type is well-formed.
1075             if (tree.recvparam != null) {
1076                 // Use a new environment to check the receiver parameter.
1077                 // Otherwise I get "might not have been initialized" errors.
1078                 // Is there a better way?
1079                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1080                 attribType(tree.recvparam, newEnv);
1081                 chk.validate(tree.recvparam, newEnv);
1082             }
1083 
1084             // Is this method a constructor?
1085             boolean isConstructor = TreeInfo.isConstructor(tree);
1086 
1087             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1088                 // lets find if this method is an accessor
1089                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1090                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1091                 if (recordComponent.isPresent()) {
1092                     // the method is a user defined accessor lets check that everything is fine
1093                     if (!tree.sym.isPublic()) {
1094                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1095                     }
1096                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1097                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1098                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1099                     }
1100                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1101                         log.error(tree,
1102                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1103                     }
1104                     if (!tree.typarams.isEmpty()) {
1105                         log.error(tree,
1106                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1107                     }
1108                     if (tree.sym.isStatic()) {
1109                         log.error(tree,
1110                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1111                     }
1112                 }
1113 
1114                 if (isConstructor) {
1115                     // if this a constructor other than the canonical one
1116                     if ((tree.sym.flags_field & RECORD) == 0) {
1117                         if (!TreeInfo.hasConstructorCall(tree, names._this)) {
1118                             log.error(tree, Errors.NonCanonicalConstructorInvokeAnotherConstructor(env.enclClass.sym));
1119                         }
1120                     } else {
1121                         // but if it is the canonical:
1122 
1123                         /* if user generated, then it shouldn't:
1124                          *     - have an accessibility stricter than that of the record type
1125                          *     - explicitly invoke any other constructor
1126                          */
1127                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1128                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1129                                 log.error(tree,
1130                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1131                                             Errors.InvalidCanonicalConstructorInRecord(
1132                                                 Fragments.Canonical,
1133                                                 env.enclClass.sym.name,
1134                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1135                                             ) :
1136                                             Errors.InvalidCanonicalConstructorInRecord(
1137                                                     Fragments.Canonical,
1138                                                     env.enclClass.sym.name,
1139                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1140                                             )
1141                                 );
1142                             }
1143 
1144                             if (TreeInfo.hasAnyConstructorCall(tree)) {
1145                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1146                                         Fragments.Canonical, env.enclClass.sym.name,
1147                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1148                             }
1149                         }
1150 
1151                         // also we want to check that no type variables have been defined
1152                         if (!tree.typarams.isEmpty()) {
1153                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1154                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1155                         }
1156 
1157                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1158                          * record components
1159                          */
1160                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1161                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1162                         for (JCVariableDecl param: tree.params) {
1163                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1164                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1165                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1166                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1167                                         Fragments.Canonical, env.enclClass.sym.name,
1168                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1169                             }
1170                             recordComponents = recordComponents.tail;
1171                             recordFieldTypes = recordFieldTypes.tail;
1172                         }
1173                     }
1174                 }
1175             }
1176 
1177             // annotation method checks
1178             if ((owner.flags() & ANNOTATION) != 0) {
1179                 // annotation method cannot have throws clause
1180                 if (tree.thrown.nonEmpty()) {
1181                     log.error(tree.thrown.head.pos(),
1182                               Errors.ThrowsNotAllowedInIntfAnnotation);
1183                 }
1184                 // annotation method cannot declare type-parameters
1185                 if (tree.typarams.nonEmpty()) {
1186                     log.error(tree.typarams.head.pos(),
1187                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1188                 }
1189                 // validate annotation method's return type (could be an annotation type)
1190                 chk.validateAnnotationType(tree.restype);
1191                 // ensure that annotation method does not clash with members of Object/Annotation
1192                 chk.validateAnnotationMethod(tree.pos(), m);
1193             }
1194 
1195             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1196                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1197 
1198             if (tree.body == null) {
1199                 // Empty bodies are only allowed for
1200                 // abstract, native, or interface methods, or for methods
1201                 // in a retrofit signature class.
1202                 if (tree.defaultValue != null) {
1203                     if ((owner.flags() & ANNOTATION) == 0)
1204                         log.error(tree.pos(),
1205                                   Errors.DefaultAllowedInIntfAnnotationMember);
1206                 }
1207                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1208                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract);
1209             } else {
1210                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1211                     if ((owner.flags() & INTERFACE) != 0) {
1212                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1213                     } else {
1214                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1215                     }
1216                 } else if ((tree.mods.flags & NATIVE) != 0) {
1217                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1218                 }
1219                 // Add an implicit super() call unless an explicit call to
1220                 // super(...) or this(...) is given
1221                 // or we are compiling class java.lang.Object.
1222                 if (isConstructor && owner.type != syms.objectType) {
1223                     if (!TreeInfo.hasAnyConstructorCall(tree)) {
1224                         JCStatement supCall = make.at(tree.body.pos).Exec(make.Apply(List.nil(),
1225                                 make.Ident(names._super), make.Idents(List.nil())));
1226                         tree.body.stats = tree.body.stats.prepend(supCall);
1227                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1228                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1229                             TreeInfo.hasConstructorCall(tree, names._super)) {
1230                         // enum constructors are not allowed to call super
1231                         // directly, so make sure there aren't any super calls
1232                         // in enum constructors, except in the compiler
1233                         // generated one.
1234                         log.error(tree.body.stats.head.pos(),
1235                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1236                     }
1237                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1238                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1239                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1240                         if (!initParamNames.equals(recordComponentNames)) {
1241                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1242                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1243                         }
1244                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1245                             log.error(tree,
1246                                     Errors.InvalidCanonicalConstructorInRecord(
1247                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1248                                             env.enclClass.sym.name,
1249                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1250                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1251                         }
1252                     }
1253                 }
1254 
1255                 // Attribute all type annotations in the body
1256                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m, null);
1257                 annotate.flush();
1258 
1259                 // Start of constructor prologue
1260                 localEnv.info.ctorPrologue = isConstructor;
1261 
1262                 // Attribute method body.
1263                 attribStat(tree.body, localEnv);
1264             }
1265 
1266             localEnv.info.scope.leave();
1267             result = tree.type = m.type;
1268         } finally {
1269             chk.setLint(prevLint);
1270             chk.setMethod(prevMethod);
1271             env.info.ctorPrologue = ctorProloguePrev;
1272         }
1273     }
1274 
1275     public void visitVarDef(JCVariableDecl tree) {
1276         // Local variables have not been entered yet, so we need to do it now:
1277         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1278             if (tree.sym != null) {
1279                 // parameters have already been entered
1280                 env.info.scope.enter(tree.sym);
1281             } else {
1282                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
1283                     if (tree.init == null) {
1284                         //cannot use 'var' without initializer
1285                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1286                         tree.vartype = make.Erroneous();
1287                     } else {
1288                         Fragment msg = canInferLocalVarType(tree);
1289                         if (msg != null) {
1290                             //cannot use 'var' with initializer which require an explicit target
1291                             //(e.g. lambda, method reference, array initializer).
1292                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1293                             tree.vartype = make.Erroneous();
1294                         }
1295                     }
1296                 }
1297                 try {
1298                     annotate.blockAnnotations();
1299                     memberEnter.memberEnter(tree, env);
1300                 } finally {
1301                     annotate.unblockAnnotations();
1302                 }
1303             }
1304         } else {
1305             doQueueScanTreeAndTypeAnnotateForVarInit(tree, env);
1306         }
1307 
1308         VarSymbol v = tree.sym;
1309         Lint lint = env.info.lint.augment(v);
1310         Lint prevLint = chk.setLint(lint);
1311 
1312         // Check that the variable's declared type is well-formed.
1313         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1314                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1315                 (tree.sym.flags() & PARAMETER) != 0;
1316         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1317 
1318         try {
1319             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1320             deferredLintHandler.flush(tree, lint);
1321             chk.checkDeprecatedAnnotation(tree.pos(), v);
1322 
1323             if (tree.init != null) {
1324                 if ((v.flags_field & FINAL) == 0 ||
1325                     !memberEnter.needsLazyConstValue(tree.init)) {
1326                     // Not a compile-time constant
1327                     // Attribute initializer in a new environment
1328                     // with the declared variable as owner.
1329                     // Check that initializer conforms to variable's declared type.
1330                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
1331                     initEnv.info.lint = lint;
1332                     // In order to catch self-references, we set the variable's
1333                     // declaration position to maximal possible value, effectively
1334                     // marking the variable as undefined.
1335                     initEnv.info.enclVar = v;
1336                     attribExpr(tree.init, initEnv, v.type);
1337                     if (tree.isImplicitlyTyped()) {
1338                         //fixup local variable type
1339                         v.type = chk.checkLocalVarType(tree, tree.init.type, tree.name);
1340                     }
1341                 }
1342                 if (tree.isImplicitlyTyped()) {
1343                     setSyntheticVariableType(tree, v.type);
1344                 }
1345             }
1346             result = tree.type = v.type;
1347             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
1348                 if (isNonArgsMethodInObject(v.name)) {
1349                     log.error(tree, Errors.IllegalRecordComponentName(v));
1350                 }
1351             }
1352             chk.checkRequiresIdentity(tree, env.info.lint);
1353         }
1354         finally {
1355             chk.setLint(prevLint);
1356         }
1357     }
1358 
1359     private void doQueueScanTreeAndTypeAnnotateForVarInit(JCVariableDecl tree, Env<AttrContext> env) {
1360         if (tree.init != null &&
1361             (tree.mods.flags & Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED) == 0 &&
1362             env.info.scope.owner.kind != MTH && env.info.scope.owner.kind != VAR) {
1363             tree.mods.flags |= Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED;
1364             // Field initializer expression need to be entered.
1365             annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym, tree);
1366             annotate.flush();
1367         }
1368     }
1369 
1370     private boolean isNonArgsMethodInObject(Name name) {
1371         for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
1372             if (s.type.getParameterTypes().isEmpty()) {
1373                 return true;
1374             }
1375         }
1376         return false;
1377     }
1378 
1379     Fragment canInferLocalVarType(JCVariableDecl tree) {
1380         LocalInitScanner lis = new LocalInitScanner();
1381         lis.scan(tree.init);
1382         return lis.badInferenceMsg;
1383     }
1384 
1385     static class LocalInitScanner extends TreeScanner {
1386         Fragment badInferenceMsg = null;
1387         boolean needsTarget = true;
1388 
1389         @Override
1390         public void visitNewArray(JCNewArray tree) {
1391             if (tree.elemtype == null && needsTarget) {
1392                 badInferenceMsg = Fragments.LocalArrayMissingTarget;
1393             }
1394         }
1395 
1396         @Override
1397         public void visitLambda(JCLambda tree) {
1398             if (needsTarget) {
1399                 badInferenceMsg = Fragments.LocalLambdaMissingTarget;
1400             }
1401         }
1402 
1403         @Override
1404         public void visitTypeCast(JCTypeCast tree) {
1405             boolean prevNeedsTarget = needsTarget;
1406             try {
1407                 needsTarget = false;
1408                 super.visitTypeCast(tree);
1409             } finally {
1410                 needsTarget = prevNeedsTarget;
1411             }
1412         }
1413 
1414         @Override
1415         public void visitReference(JCMemberReference tree) {
1416             if (needsTarget) {
1417                 badInferenceMsg = Fragments.LocalMrefMissingTarget;
1418             }
1419         }
1420 
1421         @Override
1422         public void visitNewClass(JCNewClass tree) {
1423             boolean prevNeedsTarget = needsTarget;
1424             try {
1425                 needsTarget = false;
1426                 super.visitNewClass(tree);
1427             } finally {
1428                 needsTarget = prevNeedsTarget;
1429             }
1430         }
1431 
1432         @Override
1433         public void visitApply(JCMethodInvocation tree) {
1434             boolean prevNeedsTarget = needsTarget;
1435             try {
1436                 needsTarget = false;
1437                 super.visitApply(tree);
1438             } finally {
1439                 needsTarget = prevNeedsTarget;
1440             }
1441         }
1442     }
1443 
1444     public void visitSkip(JCSkip tree) {
1445         result = null;
1446     }
1447 
1448     public void visitBlock(JCBlock tree) {
1449         if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
1450             // Block is a static or instance initializer;
1451             // let the owner of the environment be a freshly
1452             // created BLOCK-method.
1453             Symbol fakeOwner =
1454                 new MethodSymbol(tree.flags | BLOCK |
1455                     env.info.scope.owner.flags() & STRICTFP, names.empty, initBlockType,
1456                     env.info.scope.owner);
1457             final Env<AttrContext> localEnv =
1458                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
1459 
1460             if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
1461             // Attribute all type annotations in the block
1462             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner, null);
1463             annotate.flush();
1464             attribStats(tree.stats, localEnv);
1465 
1466             {
1467                 // Store init and clinit type annotations with the ClassSymbol
1468                 // to allow output in Gen.normalizeDefs.
1469                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1470                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1471                 if ((tree.flags & STATIC) != 0) {
1472                     cs.appendClassInitTypeAttributes(tas);
1473                 } else {
1474                     cs.appendInitTypeAttributes(tas);
1475                 }
1476             }
1477         } else {
1478             // Create a new local environment with a local scope.
1479             Env<AttrContext> localEnv =
1480                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1481             try {
1482                 attribStats(tree.stats, localEnv);
1483             } finally {
1484                 localEnv.info.scope.leave();
1485             }
1486         }
1487         result = null;
1488     }
1489 
1490     public void visitDoLoop(JCDoWhileLoop tree) {
1491         attribStat(tree.body, env.dup(tree));
1492         attribExpr(tree.cond, env, syms.booleanType);
1493         handleLoopConditionBindings(matchBindings, tree, tree.body);
1494         result = null;
1495     }
1496 
1497     public void visitWhileLoop(JCWhileLoop tree) {
1498         attribExpr(tree.cond, env, syms.booleanType);
1499         MatchBindings condBindings = matchBindings;
1500         // include condition's bindings when true in the body:
1501         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1502         try {
1503             attribStat(tree.body, whileEnv.dup(tree));
1504         } finally {
1505             whileEnv.info.scope.leave();
1506         }
1507         handleLoopConditionBindings(condBindings, tree, tree.body);
1508         result = null;
1509     }
1510 
1511     public void visitForLoop(JCForLoop tree) {
1512         Env<AttrContext> loopEnv =
1513             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1514         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1515         try {
1516             attribStats(tree.init, loopEnv);
1517             if (tree.cond != null) {
1518                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1519                 // include condition's bindings when true in the body and step:
1520                 condBindings = matchBindings;
1521             }
1522             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1523             try {
1524                 bodyEnv.tree = tree; // before, we were not in loop!
1525                 attribStats(tree.step, bodyEnv);
1526                 attribStat(tree.body, bodyEnv);
1527             } finally {
1528                 bodyEnv.info.scope.leave();
1529             }
1530             result = null;
1531         }
1532         finally {
1533             loopEnv.info.scope.leave();
1534         }
1535         handleLoopConditionBindings(condBindings, tree, tree.body);
1536     }
1537 
1538     /**
1539      * Include condition's bindings when false after the loop, if cannot get out of the loop
1540      */
1541     private void handleLoopConditionBindings(MatchBindings condBindings,
1542                                              JCStatement loop,
1543                                              JCStatement loopBody) {
1544         if (condBindings.bindingsWhenFalse.nonEmpty() &&
1545             !breaksTo(env, loop, loopBody)) {
1546             addBindings2Scope(loop, condBindings.bindingsWhenFalse);
1547         }
1548     }
1549 
1550     private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
1551         preFlow(body);
1552         return flow.breaksToTree(env, loop, body, make);
1553     }
1554 
1555     /**
1556      * Add given bindings to the current scope, unless there's a break to
1557      * an immediately enclosing labeled statement.
1558      */
1559     private void addBindings2Scope(JCStatement introducingStatement,
1560                                    List<BindingSymbol> bindings) {
1561         if (bindings.isEmpty()) {
1562             return ;
1563         }
1564 
1565         var searchEnv = env;
1566         while (searchEnv.tree instanceof JCLabeledStatement labeled &&
1567                labeled.body == introducingStatement) {
1568             if (breaksTo(env, labeled, labeled.body)) {
1569                 //breaking to an immediately enclosing labeled statement
1570                 return ;
1571             }
1572             searchEnv = searchEnv.next;
1573             introducingStatement = labeled;
1574         }
1575 
1576         //include condition's body when false after the while, if cannot get out of the loop
1577         bindings.forEach(env.info.scope::enter);
1578         bindings.forEach(BindingSymbol::preserveBinding);
1579     }
1580 
1581     public void visitForeachLoop(JCEnhancedForLoop tree) {
1582         Env<AttrContext> loopEnv =
1583             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1584         try {
1585             //the Formal Parameter of a for-each loop is not in the scope when
1586             //attributing the for-each expression; we mimic this by attributing
1587             //the for-each expression first (against original scope).
1588             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1589             chk.checkNonVoid(tree.pos(), exprType);
1590             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1591             if (elemtype == null) {
1592                 // or perhaps expr implements Iterable<T>?
1593                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1594                 if (base == null) {
1595                     log.error(tree.expr.pos(),
1596                               Errors.ForeachNotApplicableToType(exprType,
1597                                                                 Fragments.TypeReqArrayOrIterable));
1598                     elemtype = types.createErrorType(exprType);
1599                 } else {
1600                     List<Type> iterableParams = base.allparams();
1601                     elemtype = iterableParams.isEmpty()
1602                         ? syms.objectType
1603                         : types.wildUpperBound(iterableParams.head);
1604 
1605                     // Check the return type of the method iterator().
1606                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1607                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1608                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1609                     if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
1610                         log.error(tree.pos(),
1611                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1612                     }
1613                 }
1614             }
1615             if (tree.var.isImplicitlyTyped()) {
1616                 Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
1617                 setSyntheticVariableType(tree.var, inferredType);
1618             }
1619             attribStat(tree.var, loopEnv);
1620             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1621             loopEnv.tree = tree; // before, we were not in loop!
1622             attribStat(tree.body, loopEnv);
1623             result = null;
1624         }
1625         finally {
1626             loopEnv.info.scope.leave();
1627         }
1628     }
1629 
1630     public void visitLabelled(JCLabeledStatement tree) {
1631         // Check that label is not used in an enclosing statement
1632         Env<AttrContext> env1 = env;
1633         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1634             if (env1.tree.hasTag(LABELLED) &&
1635                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1636                 log.error(tree.pos(),
1637                           Errors.LabelAlreadyInUse(tree.label));
1638                 break;
1639             }
1640             env1 = env1.next;
1641         }
1642 
1643         attribStat(tree.body, env.dup(tree));
1644         result = null;
1645     }
1646 
1647     public void visitSwitch(JCSwitch tree) {
1648         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1649             attribStats(c.stats, caseEnv);
1650         });
1651         result = null;
1652     }
1653 
1654     public void visitSwitchExpression(JCSwitchExpression tree) {
1655         boolean wrongContext = false;
1656 
1657         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
1658                 PolyKind.STANDALONE : PolyKind.POLY;
1659 
1660         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
1661             //this means we are returning a poly conditional from void-compatible lambda expression
1662             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
1663             resultInfo = recoveryInfo;
1664             wrongContext = true;
1665         }
1666 
1667         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
1668                 unknownExprInfo :
1669                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
1670 
1671         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
1672         ListBuffer<Type> caseTypes = new ListBuffer<>();
1673 
1674         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1675             caseEnv.info.yieldResult = condInfo;
1676             attribStats(c.stats, caseEnv);
1677             new TreeScanner() {
1678                 @Override
1679                 public void visitYield(JCYield brk) {
1680                     if (brk.target == tree) {
1681                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
1682                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
1683                     }
1684                     super.visitYield(brk);
1685                 }
1686 
1687                 @Override public void visitClassDef(JCClassDecl tree) {}
1688                 @Override public void visitLambda(JCLambda tree) {}
1689             }.scan(c.stats);
1690         });
1691 
1692         if (tree.cases.isEmpty()) {
1693             log.error(tree.pos(),
1694                       Errors.SwitchExpressionEmpty);
1695         } else if (caseTypes.isEmpty()) {
1696             log.error(tree.pos(),
1697                       Errors.SwitchExpressionNoResultExpressions);
1698         }
1699 
1700         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
1701 
1702         result = tree.type = wrongContext? types.createErrorType(pt()) : check(tree, owntype, KindSelector.VAL, resultInfo);
1703     }
1704     //where:
1705         CheckContext switchExpressionContext(CheckContext checkContext) {
1706             return new Check.NestedCheckContext(checkContext) {
1707                 //this will use enclosing check context to check compatibility of
1708                 //subexpression against target type; if we are in a method check context,
1709                 //depending on whether boxing is allowed, we could have incompatibilities
1710                 @Override
1711                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
1712                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
1713                 }
1714             };
1715         }
1716 
1717     private void handleSwitch(JCTree switchTree,
1718                               JCExpression selector,
1719                               List<JCCase> cases,
1720                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
1721         Type seltype = attribExpr(selector, env);
1722         Type seltypeUnboxed = types.unboxedTypeOrType(seltype);
1723 
1724         Env<AttrContext> switchEnv =
1725             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
1726 
1727         try {
1728             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
1729             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
1730             boolean booleanSwitch = types.isSameType(seltypeUnboxed, syms.booleanType);
1731             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
1732             boolean intSwitch = types.isAssignable(seltype, syms.intType);
1733             boolean patternSwitch;
1734             if (seltype.isPrimitive() && !intSwitch) {
1735                 preview.checkSourceLevel(selector.pos(), Feature.PRIMITIVE_PATTERNS);
1736                 patternSwitch = true;
1737             }
1738             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
1739                 !intSwitch) {
1740                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
1741                 patternSwitch = true;
1742             } else {
1743                 patternSwitch = cases.stream()
1744                                      .flatMap(c -> c.labels.stream())
1745                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
1746                                                     TreeInfo.isNullCaseLabel(l));
1747             }
1748 
1749             // Attribute all cases and
1750             // check that there are no duplicate case labels or default clauses.
1751             Set<Object> constants = new HashSet<>(); // The set of case constants.
1752             boolean hasDefault = false;           // Is there a default label?
1753             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
1754             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
1755             boolean hasNullPattern = false;       // Is there a null pattern?
1756             CaseTree.CaseKind caseKind = null;
1757             boolean wasError = false;
1758             JCCaseLabel unconditionalCaseLabel = null;
1759             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
1760                 JCCase c = l.head;
1761                 if (caseKind == null) {
1762                     caseKind = c.caseKind;
1763                 } else if (caseKind != c.caseKind && !wasError) {
1764                     log.error(c.pos(),
1765                               Errors.SwitchMixingCaseTypes);
1766                     wasError = true;
1767                 }
1768                 MatchBindings currentBindings = null;
1769                 MatchBindings guardBindings = null;
1770                 for (List<JCCaseLabel> labels = c.labels; labels.nonEmpty(); labels = labels.tail) {
1771                     JCCaseLabel label = labels.head;
1772                     if (label instanceof JCConstantCaseLabel constLabel) {
1773                         JCExpression expr = constLabel.expr;
1774                         if (TreeInfo.isNull(expr)) {
1775                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
1776                             if (hasNullPattern) {
1777                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1778                             }
1779                             hasNullPattern = true;
1780                             attribExpr(expr, switchEnv, seltype);
1781                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
1782                         } else if (enumSwitch) {
1783                             Symbol sym = enumConstant(expr, seltype);
1784                             if (sym == null) {
1785                                 if (allowPatternSwitch) {
1786                                     attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1787                                     Symbol enumSym = TreeInfo.symbol(expr);
1788                                     if (enumSym == null || !enumSym.isEnum() || enumSym.kind != VAR) {
1789                                         log.error(expr.pos(), Errors.EnumLabelMustBeEnumConstant);
1790                                     } else if (!constants.add(enumSym)) {
1791                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1792                                     }
1793                                 } else {
1794                                     log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
1795                                 }
1796                             } else if (!constants.add(sym)) {
1797                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
1798                             }
1799                         } else if (errorEnumSwitch) {
1800                             //error recovery: the selector is erroneous, and all the case labels
1801                             //are identifiers. This could be an enum switch - don't report resolve
1802                             //error for the case label:
1803                             var prevResolveHelper = rs.basicLogResolveHelper;
1804                             try {
1805                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
1806                                 attribExpr(expr, switchEnv, seltype);
1807                             } finally {
1808                                 rs.basicLogResolveHelper = prevResolveHelper;
1809                             }
1810                         } else {
1811                             Type pattype = attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
1812                             if (!pattype.hasTag(ERROR)) {
1813                                 if (pattype.constValue() == null) {
1814                                     Symbol s = TreeInfo.symbol(expr);
1815                                     if (s != null && s.kind == TYP) {
1816                                         log.error(expr.pos(),
1817                                                   Errors.PatternExpected);
1818                                     } else if (s == null || !s.isEnum()) {
1819                                         log.error(expr.pos(),
1820                                                   (stringSwitch ? Errors.StringConstReq
1821                                                                 : intSwitch ? Errors.ConstExprReq
1822                                                                             : Errors.PatternOrEnumReq));
1823                                     } else if (!constants.add(s)) {
1824                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
1825                                     }
1826                                 }
1827                                 else {
1828                                     boolean isLongFloatDoubleOrBooleanConstant =
1829                                             pattype.getTag().isInSuperClassesOf(LONG) || pattype.getTag().equals(BOOLEAN);
1830                                     if (isLongFloatDoubleOrBooleanConstant) {
1831                                         preview.checkSourceLevel(label.pos(), Feature.PRIMITIVE_PATTERNS);
1832                                     }
1833                                     if (!stringSwitch && !intSwitch && !(isLongFloatDoubleOrBooleanConstant && types.isSameType(seltypeUnboxed, pattype))) {
1834                                         log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
1835                                     } else if (!constants.add(pattype.constValue())) {
1836                                         log.error(c.pos(), Errors.DuplicateCaseLabel);
1837                                     }
1838                                 }
1839                             }
1840                         }
1841                     } else if (label instanceof JCDefaultCaseLabel def) {
1842                         if (hasDefault) {
1843                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
1844                         } else if (hasUnconditionalPattern) {
1845                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
1846                         }  else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1847                             log.error(label.pos(), Errors.DefaultAndBothBooleanValues);
1848                         }
1849                         hasDefault = true;
1850                         matchBindings = MatchBindingsComputer.EMPTY;
1851                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
1852                         //pattern
1853                         JCPattern pat = patternlabel.pat;
1854                         attribExpr(pat, switchEnv, seltype);
1855                         Type primaryType = TreeInfo.primaryPatternType(pat);
1856 
1857                         if (primaryType.isPrimitive()) {
1858                             preview.checkSourceLevel(pat.pos(), Feature.PRIMITIVE_PATTERNS);
1859                         } else if (!primaryType.hasTag(TYPEVAR)) {
1860                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
1861                         }
1862                         checkCastablePattern(pat.pos(), seltype, primaryType);
1863                         Type patternType = types.erasure(primaryType);
1864                         JCExpression guard = c.guard;
1865                         if (guardBindings == null && guard != null) {
1866                             MatchBindings afterPattern = matchBindings;
1867                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
1868                             try {
1869                                 attribExpr(guard, bodyEnv, syms.booleanType);
1870                             } finally {
1871                                 bodyEnv.info.scope.leave();
1872                             }
1873 
1874                             guardBindings = matchBindings;
1875                             matchBindings = afterPattern;
1876 
1877                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
1878                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
1879                             }
1880                         }
1881                         boolean unguarded = TreeInfo.unguardedCase(c) && !pat.hasTag(RECORDPATTERN);
1882                         boolean unconditional =
1883                                 unguarded &&
1884                                 !patternType.isErroneous() &&
1885                                 types.isUnconditionallyExact(seltype, patternType);
1886                         if (unconditional) {
1887                             if (hasUnconditionalPattern) {
1888                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
1889                             } else if (hasDefault) {
1890                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
1891                             } else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
1892                                 log.error(pat.pos(), Errors.UnconditionalPatternAndBothBooleanValues);
1893                             }
1894                             hasUnconditionalPattern = true;
1895                             unconditionalCaseLabel = label;
1896                         }
1897                         lastPatternErroneous = patternType.isErroneous();
1898                     } else {
1899                         Assert.error();
1900                     }
1901                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
1902                 }
1903 
1904                 if (guardBindings != null) {
1905                     currentBindings = matchBindingsComputer.caseGuard(c, currentBindings, guardBindings);
1906                 }
1907 
1908                 Env<AttrContext> caseEnv =
1909                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
1910                 try {
1911                     attribCase.accept(c, caseEnv);
1912                 } finally {
1913                     caseEnv.info.scope.leave();
1914                 }
1915                 addVars(c.stats, switchEnv.info.scope);
1916 
1917                 preFlow(c);
1918                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
1919             }
1920             if (patternSwitch) {
1921                 chk.checkSwitchCaseStructure(cases);
1922                 chk.checkSwitchCaseLabelDominated(unconditionalCaseLabel, cases);
1923             }
1924             if (switchTree.hasTag(SWITCH)) {
1925                 ((JCSwitch) switchTree).hasUnconditionalPattern =
1926                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1927                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
1928             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
1929                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
1930                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
1931                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
1932             } else {
1933                 Assert.error(switchTree.getTag().name());
1934             }
1935         } finally {
1936             switchEnv.info.scope.leave();
1937         }
1938     }
1939     // where
1940         private ResultInfo caseLabelResultInfo(Type seltype) {
1941             return new ResultInfo(KindSelector.VAL_TYP,
1942                                   !seltype.hasTag(ERROR) ? seltype
1943                                                          : Type.noType);
1944         }
1945         /** Add any variables defined in stats to the switch scope. */
1946         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
1947             for (;stats.nonEmpty(); stats = stats.tail) {
1948                 JCTree stat = stats.head;
1949                 if (stat.hasTag(VARDEF))
1950                     switchScope.enter(((JCVariableDecl) stat).sym);
1951             }
1952         }
1953     // where
1954     /** Return the selected enumeration constant symbol, or null. */
1955     private Symbol enumConstant(JCTree tree, Type enumType) {
1956         if (tree.hasTag(IDENT)) {
1957             JCIdent ident = (JCIdent)tree;
1958             Name name = ident.name;
1959             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
1960                 if (sym.kind == VAR) {
1961                     Symbol s = ident.sym = sym;
1962                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
1963                     ident.type = s.type;
1964                     return ((s.flags_field & Flags.ENUM) == 0)
1965                         ? null : s;
1966                 }
1967             }
1968         }
1969         return null;
1970     }
1971 
1972     public void visitSynchronized(JCSynchronized tree) {
1973         chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
1974         if (tree.lock.type != null && tree.lock.type.isValueBased()) {
1975             env.info.lint.logIfEnabled(tree.pos(), LintWarnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
1976         }
1977         attribStat(tree.body, env);
1978         result = null;
1979     }
1980 
1981     public void visitTry(JCTry tree) {
1982         // Create a new local environment with a local
1983         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
1984         try {
1985             boolean isTryWithResource = tree.resources.nonEmpty();
1986             // Create a nested environment for attributing the try block if needed
1987             Env<AttrContext> tryEnv = isTryWithResource ?
1988                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
1989                 localEnv;
1990             try {
1991                 // Attribute resource declarations
1992                 for (JCTree resource : tree.resources) {
1993                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
1994                         @Override
1995                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
1996                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
1997                         }
1998                     };
1999                     ResultInfo twrResult =
2000                         new ResultInfo(KindSelector.VAR,
2001                                        syms.autoCloseableType,
2002                                        twrContext);
2003                     if (resource.hasTag(VARDEF)) {
2004                         attribStat(resource, tryEnv);
2005                         twrResult.check(resource, resource.type);
2006 
2007                         //check that resource type cannot throw InterruptedException
2008                         checkAutoCloseable(resource.pos(), localEnv, resource.type);
2009 
2010                         VarSymbol var = ((JCVariableDecl) resource).sym;
2011 
2012                         var.flags_field |= Flags.FINAL;
2013                         var.setData(ElementKind.RESOURCE_VARIABLE);
2014                     } else {
2015                         attribTree(resource, tryEnv, twrResult);
2016                     }
2017                 }
2018                 // Attribute body
2019                 attribStat(tree.body, tryEnv);
2020             } finally {
2021                 if (isTryWithResource)
2022                     tryEnv.info.scope.leave();
2023             }
2024 
2025             // Attribute catch clauses
2026             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
2027                 JCCatch c = l.head;
2028                 Env<AttrContext> catchEnv =
2029                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
2030                 try {
2031                     Type ctype = attribStat(c.param, catchEnv);
2032                     if (TreeInfo.isMultiCatch(c)) {
2033                         //multi-catch parameter is implicitly marked as final
2034                         c.param.sym.flags_field |= FINAL | UNION;
2035                     }
2036                     if (c.param.sym.kind == VAR) {
2037                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
2038                     }
2039                     chk.checkType(c.param.vartype.pos(),
2040                                   chk.checkClassType(c.param.vartype.pos(), ctype),
2041                                   syms.throwableType);
2042                     attribStat(c.body, catchEnv);
2043                 } finally {
2044                     catchEnv.info.scope.leave();
2045                 }
2046             }
2047 
2048             // Attribute finalizer
2049             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
2050             result = null;
2051         }
2052         finally {
2053             localEnv.info.scope.leave();
2054         }
2055     }
2056 
2057     void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
2058         if (!resource.isErroneous() &&
2059             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
2060             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
2061             Symbol close = syms.noSymbol;
2062             Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
2063             try {
2064                 close = rs.resolveQualifiedMethod(pos,
2065                         env,
2066                         types.skipTypeVars(resource, false),
2067                         names.close,
2068                         List.nil(),
2069                         List.nil());
2070             }
2071             finally {
2072                 log.popDiagnosticHandler(discardHandler);
2073             }
2074             if (close.kind == MTH &&
2075                     close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
2076                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes())) {
2077                 env.info.lint.logIfEnabled(pos, LintWarnings.TryResourceThrowsInterruptedExc(resource));
2078             }
2079         }
2080     }
2081 
2082     public void visitConditional(JCConditional tree) {
2083         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2084         MatchBindings condBindings = matchBindings;
2085 
2086         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2087                 isBooleanOrNumeric(env, tree)) ?
2088                 PolyKind.STANDALONE : PolyKind.POLY;
2089 
2090         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2091             //this means we are returning a poly conditional from void-compatible lambda expression
2092             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2093             result = tree.type = types.createErrorType(resultInfo.pt);
2094             return;
2095         }
2096 
2097         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2098                 unknownExprInfo :
2099                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2100 
2101 
2102         // x ? y : z
2103         // include x's bindings when true in y
2104         // include x's bindings when false in z
2105 
2106         Type truetype;
2107         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2108         try {
2109             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2110         } finally {
2111             trueEnv.info.scope.leave();
2112         }
2113 
2114         MatchBindings trueBindings = matchBindings;
2115 
2116         Type falsetype;
2117         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2118         try {
2119             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2120         } finally {
2121             falseEnv.info.scope.leave();
2122         }
2123 
2124         MatchBindings falseBindings = matchBindings;
2125 
2126         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2127                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2128                          List.of(truetype, falsetype)) : pt();
2129         if (condtype.constValue() != null &&
2130                 truetype.constValue() != null &&
2131                 falsetype.constValue() != null &&
2132                 !owntype.hasTag(NONE)) {
2133             //constant folding
2134             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2135         }
2136         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2137         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2138     }
2139     //where
2140         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2141             switch (tree.getTag()) {
2142                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2143                               ((JCLiteral)tree).typetag == BOOLEAN ||
2144                               ((JCLiteral)tree).typetag == BOT;
2145                 case LAMBDA: case REFERENCE: return false;
2146                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2147                 case CONDEXPR:
2148                     JCConditional condTree = (JCConditional)tree;
2149                     return isBooleanOrNumeric(env, condTree.truepart) &&
2150                             isBooleanOrNumeric(env, condTree.falsepart);
2151                 case APPLY:
2152                     JCMethodInvocation speculativeMethodTree =
2153                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2154                                     tree, env, unknownExprInfo,
2155                                     argumentAttr.withLocalCacheContext());
2156                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2157                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2158                             env.enclClass.type :
2159                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2160                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2161                     return primitiveOrBoxed(owntype);
2162                 case NEWCLASS:
2163                     JCExpression className =
2164                             removeClassParams.translate(((JCNewClass)tree).clazz);
2165                     JCExpression speculativeNewClassTree =
2166                             (JCExpression)deferredAttr.attribSpeculative(
2167                                     className, env, unknownTypeInfo,
2168                                     argumentAttr.withLocalCacheContext());
2169                     return primitiveOrBoxed(speculativeNewClassTree.type);
2170                 default:
2171                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2172                             argumentAttr.withLocalCacheContext()).type;
2173                     return primitiveOrBoxed(speculativeType);
2174             }
2175         }
2176         //where
2177             boolean primitiveOrBoxed(Type t) {
2178                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2179             }
2180 
2181             TreeTranslator removeClassParams = new TreeTranslator() {
2182                 @Override
2183                 public void visitTypeApply(JCTypeApply tree) {
2184                     result = translate(tree.clazz);
2185                 }
2186             };
2187 
2188         CheckContext conditionalContext(CheckContext checkContext) {
2189             return new Check.NestedCheckContext(checkContext) {
2190                 //this will use enclosing check context to check compatibility of
2191                 //subexpression against target type; if we are in a method check context,
2192                 //depending on whether boxing is allowed, we could have incompatibilities
2193                 @Override
2194                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2195                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2196                 }
2197             };
2198         }
2199 
2200         /** Compute the type of a conditional expression, after
2201          *  checking that it exists.  See JLS 15.25. Does not take into
2202          *  account the special case where condition and both arms
2203          *  are constants.
2204          *
2205          *  @param pos      The source position to be used for error
2206          *                  diagnostics.
2207          *  @param thentype The type of the expression's then-part.
2208          *  @param elsetype The type of the expression's else-part.
2209          */
2210         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2211             if (condTypes.isEmpty()) {
2212                 return syms.objectType; //TODO: how to handle?
2213             }
2214             Type first = condTypes.head;
2215             // If same type, that is the result
2216             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2217                 return first.baseType();
2218 
2219             List<Type> unboxedTypes = condTypes.stream()
2220                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2221                                                .collect(List.collector());
2222 
2223             // Otherwise, if both arms can be converted to a numeric
2224             // type, return the least numeric type that fits both arms
2225             // (i.e. return larger of the two, or return int if one
2226             // arm is short, the other is char).
2227             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2228                 // If one arm has an integer subrange type (i.e., byte,
2229                 // short, or char), and the other is an integer constant
2230                 // that fits into the subrange, return the subrange type.
2231                 for (Type type : unboxedTypes) {
2232                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2233                         continue;
2234                     }
2235                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2236                         return type.baseType();
2237                 }
2238 
2239                 for (TypeTag tag : primitiveTags) {
2240                     Type candidate = syms.typeOfTag[tag.ordinal()];
2241                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2242                         return candidate;
2243                     }
2244                 }
2245             }
2246 
2247             // Those were all the cases that could result in a primitive
2248             condTypes = condTypes.stream()
2249                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
2250                                  .collect(List.collector());
2251 
2252             for (Type type : condTypes) {
2253                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2254                     return type.baseType();
2255             }
2256 
2257             Iterator<DiagnosticPosition> posIt = positions.iterator();
2258 
2259             condTypes = condTypes.stream()
2260                                  .map(t -> chk.checkNonVoid(posIt.next(), t))
2261                                  .collect(List.collector());
2262 
2263             // both are known to be reference types.  The result is
2264             // lub(thentype,elsetype). This cannot fail, as it will
2265             // always be possible to infer "Object" if nothing better.
2266             return types.lub(condTypes.stream()
2267                         .map(t -> t.baseType())
2268                         .filter(t -> !t.hasTag(BOT))
2269                         .collect(List.collector()));
2270         }
2271 
2272     static final TypeTag[] primitiveTags = new TypeTag[]{
2273         BYTE,
2274         CHAR,
2275         SHORT,
2276         INT,
2277         LONG,
2278         FLOAT,
2279         DOUBLE,
2280         BOOLEAN,
2281     };
2282 
2283     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2284         return bindingEnv(env, env.tree, bindings);
2285     }
2286 
2287     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2288         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2289         bindings.forEach(env1.info.scope::enter);
2290         return env1;
2291     }
2292 
2293     public void visitIf(JCIf tree) {
2294         attribExpr(tree.cond, env, syms.booleanType);
2295 
2296         // if (x) { y } [ else z ]
2297         // include x's bindings when true in y
2298         // include x's bindings when false in z
2299 
2300         MatchBindings condBindings = matchBindings;
2301         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2302 
2303         try {
2304             attribStat(tree.thenpart, thenEnv);
2305         } finally {
2306             thenEnv.info.scope.leave();
2307         }
2308 
2309         preFlow(tree.thenpart);
2310         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2311         boolean aliveAfterElse;
2312 
2313         if (tree.elsepart != null) {
2314             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2315             try {
2316                 attribStat(tree.elsepart, elseEnv);
2317             } finally {
2318                 elseEnv.info.scope.leave();
2319             }
2320             preFlow(tree.elsepart);
2321             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2322         } else {
2323             aliveAfterElse = true;
2324         }
2325 
2326         chk.checkEmptyIf(tree);
2327 
2328         List<BindingSymbol> afterIfBindings = List.nil();
2329 
2330         if (aliveAfterThen && !aliveAfterElse) {
2331             afterIfBindings = condBindings.bindingsWhenTrue;
2332         } else if (aliveAfterElse && !aliveAfterThen) {
2333             afterIfBindings = condBindings.bindingsWhenFalse;
2334         }
2335 
2336         addBindings2Scope(tree, afterIfBindings);
2337 
2338         result = null;
2339     }
2340 
2341         void preFlow(JCTree tree) {
2342             attrRecover.doRecovery();
2343             new PostAttrAnalyzer() {
2344                 @Override
2345                 public void scan(JCTree tree) {
2346                     if (tree == null ||
2347                             (tree.type != null &&
2348                             tree.type == Type.stuckType)) {
2349                         //don't touch stuck expressions!
2350                         return;
2351                     }
2352                     super.scan(tree);
2353                 }
2354 
2355                 @Override
2356                 public void visitClassDef(JCClassDecl that) {
2357                     if (that.sym != null) {
2358                         // Method preFlow shouldn't visit class definitions
2359                         // that have not been entered and attributed.
2360                         // See JDK-8254557 and JDK-8203277 for more details.
2361                         super.visitClassDef(that);
2362                     }
2363                 }
2364 
2365                 @Override
2366                 public void visitLambda(JCLambda that) {
2367                     if (that.type != null) {
2368                         // Method preFlow shouldn't visit lambda expressions
2369                         // that have not been entered and attributed.
2370                         // See JDK-8254557 and JDK-8203277 for more details.
2371                         super.visitLambda(that);
2372                     }
2373                 }
2374             }.scan(tree);
2375         }
2376 
2377     public void visitExec(JCExpressionStatement tree) {
2378         //a fresh environment is required for 292 inference to work properly ---
2379         //see Infer.instantiatePolymorphicSignatureInstance()
2380         Env<AttrContext> localEnv = env.dup(tree);
2381         attribExpr(tree.expr, localEnv);
2382         result = null;
2383     }
2384 
2385     public void visitBreak(JCBreak tree) {
2386         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2387         result = null;
2388     }
2389 
2390     public void visitYield(JCYield tree) {
2391         if (env.info.yieldResult != null) {
2392             attribTree(tree.value, env, env.info.yieldResult);
2393             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2394         } else {
2395             log.error(tree.pos(), tree.value.hasTag(PARENS)
2396                     ? Errors.NoSwitchExpressionQualify
2397                     : Errors.NoSwitchExpression);
2398             attribTree(tree.value, env, unknownExprInfo);
2399         }
2400         result = null;
2401     }
2402 
2403     public void visitContinue(JCContinue tree) {
2404         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2405         result = null;
2406     }
2407     //where
2408         /** Return the target of a break, continue or yield statement,
2409          *  if it exists, report an error if not.
2410          *  Note: The target of a labelled break or continue is the
2411          *  (non-labelled) statement tree referred to by the label,
2412          *  not the tree representing the labelled statement itself.
2413          *
2414          *  @param pos     The position to be used for error diagnostics
2415          *  @param tag     The tag of the jump statement. This is either
2416          *                 Tree.BREAK or Tree.CONTINUE.
2417          *  @param label   The label of the jump statement, or null if no
2418          *                 label is given.
2419          *  @param env     The environment current at the jump statement.
2420          */
2421         private JCTree findJumpTarget(DiagnosticPosition pos,
2422                                                    JCTree.Tag tag,
2423                                                    Name label,
2424                                                    Env<AttrContext> env) {
2425             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2426 
2427             if (jumpTarget.snd != null) {
2428                 log.error(pos, jumpTarget.snd);
2429             }
2430 
2431             return jumpTarget.fst;
2432         }
2433         /** Return the target of a break or continue statement, if it exists,
2434          *  report an error if not.
2435          *  Note: The target of a labelled break or continue is the
2436          *  (non-labelled) statement tree referred to by the label,
2437          *  not the tree representing the labelled statement itself.
2438          *
2439          *  @param tag     The tag of the jump statement. This is either
2440          *                 Tree.BREAK or Tree.CONTINUE.
2441          *  @param label   The label of the jump statement, or null if no
2442          *                 label is given.
2443          *  @param env     The environment current at the jump statement.
2444          */
2445         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2446                                                                        Name label,
2447                                                                        Env<AttrContext> env) {
2448             // Search environments outwards from the point of jump.
2449             Env<AttrContext> env1 = env;
2450             JCDiagnostic.Error pendingError = null;
2451             LOOP:
2452             while (env1 != null) {
2453                 switch (env1.tree.getTag()) {
2454                     case LABELLED:
2455                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2456                         if (label == labelled.label) {
2457                             // If jump is a continue, check that target is a loop.
2458                             if (tag == CONTINUE) {
2459                                 if (!labelled.body.hasTag(DOLOOP) &&
2460                                         !labelled.body.hasTag(WHILELOOP) &&
2461                                         !labelled.body.hasTag(FORLOOP) &&
2462                                         !labelled.body.hasTag(FOREACHLOOP)) {
2463                                     pendingError = Errors.NotLoopLabel(label);
2464                                 }
2465                                 // Found labelled statement target, now go inwards
2466                                 // to next non-labelled tree.
2467                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2468                             } else {
2469                                 return Pair.of(labelled, pendingError);
2470                             }
2471                         }
2472                         break;
2473                     case DOLOOP:
2474                     case WHILELOOP:
2475                     case FORLOOP:
2476                     case FOREACHLOOP:
2477                         if (label == null) return Pair.of(env1.tree, pendingError);
2478                         break;
2479                     case SWITCH:
2480                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2481                         break;
2482                     case SWITCH_EXPRESSION:
2483                         if (tag == YIELD) {
2484                             return Pair.of(env1.tree, null);
2485                         } else if (tag == BREAK) {
2486                             pendingError = Errors.BreakOutsideSwitchExpression;
2487                         } else {
2488                             pendingError = Errors.ContinueOutsideSwitchExpression;
2489                         }
2490                         break;
2491                     case LAMBDA:
2492                     case METHODDEF:
2493                     case CLASSDEF:
2494                         break LOOP;
2495                     default:
2496                 }
2497                 env1 = env1.next;
2498             }
2499             if (label != null)
2500                 return Pair.of(null, Errors.UndefLabel(label));
2501             else if (pendingError != null)
2502                 return Pair.of(null, pendingError);
2503             else if (tag == CONTINUE)
2504                 return Pair.of(null, Errors.ContOutsideLoop);
2505             else
2506                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2507         }
2508 
2509     public void visitReturn(JCReturn tree) {
2510         // Check that there is an enclosing method which is
2511         // nested within than the enclosing class.
2512         if (env.info.returnResult == null) {
2513             log.error(tree.pos(), Errors.RetOutsideMeth);
2514         } else if (env.info.yieldResult != null) {
2515             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2516             if (tree.expr != null) {
2517                 attribExpr(tree.expr, env, env.info.yieldResult.pt);
2518             }
2519         } else if (!env.info.isLambda &&
2520                 env.enclMethod != null &&
2521                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2522             log.error(env.enclMethod,
2523                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2524         } else {
2525             // Attribute return expression, if it exists, and check that
2526             // it conforms to result type of enclosing method.
2527             if (tree.expr != null) {
2528                 if (env.info.returnResult.pt.hasTag(VOID)) {
2529                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2530                               diags.fragment(Fragments.UnexpectedRetVal));
2531                 }
2532                 attribTree(tree.expr, env, env.info.returnResult);
2533             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2534                     !env.info.returnResult.pt.hasTag(NONE)) {
2535                 env.info.returnResult.checkContext.report(tree.pos(),
2536                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2537             }
2538         }
2539         result = null;
2540     }
2541 
2542     public void visitThrow(JCThrow tree) {
2543         Type owntype = attribExpr(tree.expr, env, Type.noType);
2544         chk.checkType(tree, owntype, syms.throwableType);
2545         result = null;
2546     }
2547 
2548     public void visitAssert(JCAssert tree) {
2549         attribExpr(tree.cond, env, syms.booleanType);
2550         if (tree.detail != null) {
2551             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2552         }
2553         result = null;
2554     }
2555 
2556      /** Visitor method for method invocations.
2557      *  NOTE: The method part of an application will have in its type field
2558      *        the return type of the method, not the method's type itself!
2559      */
2560     public void visitApply(JCMethodInvocation tree) {
2561         // The local environment of a method application is
2562         // a new environment nested in the current one.
2563         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2564 
2565         // The types of the actual method arguments.
2566         List<Type> argtypes;
2567 
2568         // The types of the actual method type arguments.
2569         List<Type> typeargtypes = null;
2570 
2571         Name methName = TreeInfo.name(tree.meth);
2572 
2573         boolean isConstructorCall =
2574             methName == names._this || methName == names._super;
2575 
2576         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2577         if (isConstructorCall) {
2578 
2579             // Attribute arguments, yielding list of argument types.
2580             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2581             argtypes = argtypesBuf.toList();
2582             typeargtypes = attribTypes(tree.typeargs, localEnv);
2583 
2584             // Done with this()/super() parameters. End of constructor prologue.
2585             env.info.ctorPrologue = false;
2586 
2587             // Variable `site' points to the class in which the called
2588             // constructor is defined.
2589             Type site = env.enclClass.sym.type;
2590             if (methName == names._super) {
2591                 if (site == syms.objectType) {
2592                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2593                     site = types.createErrorType(syms.objectType);
2594                 } else {
2595                     site = types.supertype(site);
2596                 }
2597             }
2598 
2599             if (site.hasTag(CLASS)) {
2600                 Type encl = site.getEnclosingType();
2601                 while (encl != null && encl.hasTag(TYPEVAR))
2602                     encl = encl.getUpperBound();
2603                 if (encl.hasTag(CLASS)) {
2604                     // we are calling a nested class
2605 
2606                     if (tree.meth.hasTag(SELECT)) {
2607                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2608 
2609                         // We are seeing a prefixed call, of the form
2610                         //     <expr>.super(...).
2611                         // Check that the prefix expression conforms
2612                         // to the outer instance type of the class.
2613                         chk.checkRefType(qualifier.pos(),
2614                                          attribExpr(qualifier, localEnv,
2615                                                     encl));
2616                     }
2617                 } else if (tree.meth.hasTag(SELECT)) {
2618                     log.error(tree.meth.pos(),
2619                               Errors.IllegalQualNotIcls(site.tsym));
2620                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2621                 }
2622 
2623                 if (tree.meth.hasTag(IDENT)) {
2624                     // non-qualified super(...) call; check whether explicit constructor
2625                     // invocation is well-formed. If the super class is an inner class,
2626                     // make sure that an appropriate implicit qualifier exists. If the super
2627                     // class is a local class, make sure that the current class is defined
2628                     // in the same context as the local class.
2629                     checkNewInnerClass(tree.meth.pos(), localEnv, site, true);
2630                 }
2631 
2632                 // if we're calling a java.lang.Enum constructor,
2633                 // prefix the implicit String and int parameters
2634                 if (site.tsym == syms.enumSym)
2635                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
2636 
2637                 // Resolve the called constructor under the assumption
2638                 // that we are referring to a superclass instance of the
2639                 // current instance (JLS ???).
2640                 boolean selectSuperPrev = localEnv.info.selectSuper;
2641                 localEnv.info.selectSuper = true;
2642                 localEnv.info.pendingResolutionPhase = null;
2643                 Symbol sym = rs.resolveConstructor(
2644                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
2645                 localEnv.info.selectSuper = selectSuperPrev;
2646 
2647                 // Set method symbol to resolved constructor...
2648                 TreeInfo.setSymbol(tree.meth, sym);
2649 
2650                 // ...and check that it is legal in the current context.
2651                 // (this will also set the tree's type)
2652                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2653                 checkId(tree.meth, site, sym, localEnv,
2654                         new ResultInfo(kind, mpt));
2655             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
2656                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2657             }
2658             // Otherwise, `site' is an error type and we do nothing
2659             result = tree.type = syms.voidType;
2660         } else {
2661             // Otherwise, we are seeing a regular method call.
2662             // Attribute the arguments, yielding list of argument types, ...
2663             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2664             argtypes = argtypesBuf.toList();
2665             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
2666 
2667             // ... and attribute the method using as a prototype a methodtype
2668             // whose formal argument types is exactly the list of actual
2669             // arguments (this will also set the method symbol).
2670             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2671             localEnv.info.pendingResolutionPhase = null;
2672             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
2673 
2674             // Compute the result type.
2675             Type restype = mtype.getReturnType();
2676             if (restype.hasTag(WILDCARD))
2677                 throw new AssertionError(mtype);
2678 
2679             Type qualifier = (tree.meth.hasTag(SELECT))
2680                     ? ((JCFieldAccess) tree.meth).selected.type
2681                     : env.enclClass.sym.type;
2682             Symbol msym = TreeInfo.symbol(tree.meth);
2683             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
2684 
2685             chk.checkRefTypes(tree.typeargs, typeargtypes);
2686 
2687             // Check that value of resulting type is admissible in the
2688             // current context.  Also, capture the return type
2689             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
2690             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
2691         }
2692         chk.checkRequiresIdentity(tree, env.info.lint);
2693         chk.validate(tree.typeargs, localEnv);
2694     }
2695     //where
2696         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
2697             if (msym != null &&
2698                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
2699                     methodName == names.getClass &&
2700                     argtypes.isEmpty()) {
2701                 // as a special case, x.getClass() has type Class<? extends |X|>
2702                 return new ClassType(restype.getEnclosingType(),
2703                         List.of(new WildcardType(types.erasure(qualifierType.baseType()),
2704                                 BoundKind.EXTENDS,
2705                                 syms.boundClass)),
2706                         restype.tsym,
2707                         restype.getMetadata());
2708             } else if (msym != null &&
2709                     msym.owner == syms.arrayClass &&
2710                     methodName == names.clone &&
2711                     types.isArray(qualifierType)) {
2712                 // as a special case, array.clone() has a result that is
2713                 // the same as static type of the array being cloned
2714                 return qualifierType;
2715             } else {
2716                 return restype;
2717             }
2718         }
2719 
2720         /** Obtain a method type with given argument types.
2721          */
2722         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
2723             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
2724             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
2725         }
2726 
2727     public void visitNewClass(final JCNewClass tree) {
2728         Type owntype = types.createErrorType(tree.type);
2729 
2730         // The local environment of a class creation is
2731         // a new environment nested in the current one.
2732         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2733 
2734         // The anonymous inner class definition of the new expression,
2735         // if one is defined by it.
2736         JCClassDecl cdef = tree.def;
2737 
2738         // If enclosing class is given, attribute it, and
2739         // complete class name to be fully qualified
2740         JCExpression clazz = tree.clazz; // Class field following new
2741         JCExpression clazzid;            // Identifier in class field
2742         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
2743         annoclazzid = null;
2744 
2745         if (clazz.hasTag(TYPEAPPLY)) {
2746             clazzid = ((JCTypeApply) clazz).clazz;
2747             if (clazzid.hasTag(ANNOTATED_TYPE)) {
2748                 annoclazzid = (JCAnnotatedType) clazzid;
2749                 clazzid = annoclazzid.underlyingType;
2750             }
2751         } else {
2752             if (clazz.hasTag(ANNOTATED_TYPE)) {
2753                 annoclazzid = (JCAnnotatedType) clazz;
2754                 clazzid = annoclazzid.underlyingType;
2755             } else {
2756                 clazzid = clazz;
2757             }
2758         }
2759 
2760         JCExpression clazzid1 = clazzid; // The same in fully qualified form
2761 
2762         if (tree.encl != null) {
2763             // We are seeing a qualified new, of the form
2764             //    <expr>.new C <...> (...) ...
2765             // In this case, we let clazz stand for the name of the
2766             // allocated class C prefixed with the type of the qualifier
2767             // expression, so that we can
2768             // resolve it with standard techniques later. I.e., if
2769             // <expr> has type T, then <expr>.new C <...> (...)
2770             // yields a clazz T.C.
2771             Type encltype = chk.checkRefType(tree.encl.pos(),
2772                                              attribExpr(tree.encl, env));
2773             // TODO 308: in <expr>.new C, do we also want to add the type annotations
2774             // from expr to the combined type, or not? Yes, do this.
2775             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
2776                                                  ((JCIdent) clazzid).name);
2777 
2778             EndPosTable endPosTable = this.env.toplevel.endPositions;
2779             endPosTable.storeEnd(clazzid1, clazzid.getEndPosition(endPosTable));
2780             if (clazz.hasTag(ANNOTATED_TYPE)) {
2781                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
2782                 List<JCAnnotation> annos = annoType.annotations;
2783 
2784                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
2785                     clazzid1 = make.at(tree.pos).
2786                         TypeApply(clazzid1,
2787                                   ((JCTypeApply) clazz).arguments);
2788                 }
2789 
2790                 clazzid1 = make.at(tree.pos).
2791                     AnnotatedType(annos, clazzid1);
2792             } else if (clazz.hasTag(TYPEAPPLY)) {
2793                 clazzid1 = make.at(tree.pos).
2794                     TypeApply(clazzid1,
2795                               ((JCTypeApply) clazz).arguments);
2796             }
2797 
2798             clazz = clazzid1;
2799         }
2800 
2801         // Attribute clazz expression and store
2802         // symbol + type back into the attributed tree.
2803         Type clazztype;
2804 
2805         try {
2806             env.info.isAnonymousNewClass = tree.def != null;
2807             clazztype = TreeInfo.isEnumInit(env.tree) ?
2808                 attribIdentAsEnumType(env, (JCIdent)clazz) :
2809                 attribType(clazz, env);
2810         } finally {
2811             env.info.isAnonymousNewClass = false;
2812         }
2813 
2814         clazztype = chk.checkDiamond(tree, clazztype);
2815         chk.validate(clazz, localEnv);
2816         if (tree.encl != null) {
2817             // We have to work in this case to store
2818             // symbol + type back into the attributed tree.
2819             tree.clazz.type = clazztype;
2820             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
2821             clazzid.type = ((JCIdent) clazzid).sym.type;
2822             if (annoclazzid != null) {
2823                 annoclazzid.type = clazzid.type;
2824             }
2825             if (!clazztype.isErroneous()) {
2826                 if (cdef != null && clazztype.tsym.isInterface()) {
2827                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
2828                 } else if (clazztype.tsym.isStatic()) {
2829                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
2830                 }
2831             }
2832         } else {
2833             // Check for the existence of an apropos outer instance
2834             checkNewInnerClass(tree.pos(), env, clazztype, false);
2835         }
2836 
2837         // Attribute constructor arguments.
2838         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2839         final KindSelector pkind =
2840             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
2841         List<Type> argtypes = argtypesBuf.toList();
2842         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
2843 
2844         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
2845             // Enums may not be instantiated except implicitly
2846             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
2847                 (!env.tree.hasTag(VARDEF) ||
2848                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
2849                  ((JCVariableDecl) env.tree).init != tree))
2850                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
2851 
2852             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
2853                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
2854             boolean skipNonDiamondPath = false;
2855             // Check that class is not abstract
2856             if (cdef == null && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
2857                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
2858                 log.error(tree.pos(),
2859                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
2860                 skipNonDiamondPath = true;
2861             } else if (cdef != null && clazztype.tsym.isInterface()) {
2862                 // Check that no constructor arguments are given to
2863                 // anonymous classes implementing an interface
2864                 if (!argtypes.isEmpty())
2865                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
2866 
2867                 if (!typeargtypes.isEmpty())
2868                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
2869 
2870                 // Error recovery: pretend no arguments were supplied.
2871                 argtypes = List.nil();
2872                 typeargtypes = List.nil();
2873                 skipNonDiamondPath = true;
2874             }
2875             if (TreeInfo.isDiamond(tree)) {
2876                 ClassType site = new ClassType(clazztype.getEnclosingType(),
2877                             clazztype.tsym.type.getTypeArguments(),
2878                                                clazztype.tsym,
2879                                                clazztype.getMetadata());
2880 
2881                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
2882                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
2883                 diamondEnv.info.pendingResolutionPhase = null;
2884 
2885                 //if the type of the instance creation expression is a class type
2886                 //apply method resolution inference (JLS 15.12.2.7). The return type
2887                 //of the resolved constructor will be a partially instantiated type
2888                 Symbol constructor = rs.resolveDiamond(tree.pos(),
2889                             diamondEnv,
2890                             site,
2891                             argtypes,
2892                             typeargtypes);
2893                 tree.constructor = constructor.baseSymbol();
2894 
2895                 final TypeSymbol csym = clazztype.tsym;
2896                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
2897                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
2898                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
2899                 constructorType = checkId(tree, site,
2900                         constructor,
2901                         diamondEnv,
2902                         diamondResult);
2903 
2904                 tree.clazz.type = types.createErrorType(clazztype);
2905                 if (!constructorType.isErroneous()) {
2906                     tree.clazz.type = clazz.type = constructorType.getReturnType();
2907                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
2908                 }
2909                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
2910             }
2911 
2912             // Resolve the called constructor under the assumption
2913             // that we are referring to a superclass instance of the
2914             // current instance (JLS ???).
2915             else if (!skipNonDiamondPath) {
2916                 //the following code alters some of the fields in the current
2917                 //AttrContext - hence, the current context must be dup'ed in
2918                 //order to avoid downstream failures
2919                 Env<AttrContext> rsEnv = localEnv.dup(tree);
2920                 rsEnv.info.selectSuper = cdef != null;
2921                 rsEnv.info.pendingResolutionPhase = null;
2922                 tree.constructor = rs.resolveConstructor(
2923                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
2924                 if (cdef == null) { //do not check twice!
2925                     tree.constructorType = checkId(tree,
2926                             clazztype,
2927                             tree.constructor,
2928                             rsEnv,
2929                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
2930                     if (rsEnv.info.lastResolveVarargs())
2931                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
2932                 }
2933             }
2934 
2935             chk.checkRequiresIdentity(tree, env.info.lint);
2936 
2937             if (cdef != null) {
2938                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
2939                 return;
2940             }
2941 
2942             if (tree.constructor != null && tree.constructor.kind == MTH)
2943                 owntype = clazztype;
2944         }
2945         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2946         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2947         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
2948             //we need to wait for inference to finish and then replace inference vars in the constructor type
2949             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
2950                     instantiatedContext -> {
2951                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
2952                     });
2953         }
2954         chk.validate(tree.typeargs, localEnv);
2955     }
2956 
2957         // where
2958         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
2959                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
2960                                                    List<Type> argtypes, List<Type> typeargtypes,
2961                                                    KindSelector pkind) {
2962             // We are seeing an anonymous class instance creation.
2963             // In this case, the class instance creation
2964             // expression
2965             //
2966             //    E.new <typeargs1>C<typargs2>(args) { ... }
2967             //
2968             // is represented internally as
2969             //
2970             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
2971             //
2972             // This expression is then *transformed* as follows:
2973             //
2974             // (1) add an extends or implements clause
2975             // (2) add a constructor.
2976             //
2977             // For instance, if C is a class, and ET is the type of E,
2978             // the expression
2979             //
2980             //    E.new <typeargs1>C<typargs2>(args) { ... }
2981             //
2982             // is translated to (where X is a fresh name and typarams is the
2983             // parameter list of the super constructor):
2984             //
2985             //   new <typeargs1>X(<*nullchk*>E, args) where
2986             //     X extends C<typargs2> {
2987             //       <typarams> X(ET e, args) {
2988             //         e.<typeargs1>super(args)
2989             //       }
2990             //       ...
2991             //     }
2992             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
2993             Type enclType = clazztype.getEnclosingType();
2994             if (enclType != null &&
2995                     enclType.hasTag(CLASS) &&
2996                     !chk.checkDenotable((ClassType)enclType)) {
2997                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
2998             }
2999             final boolean isDiamond = TreeInfo.isDiamond(tree);
3000             if (isDiamond
3001                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
3002                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
3003                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
3004                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
3005                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
3006                         instantiatedContext -> {
3007                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
3008                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
3009                             ResultInfo prevResult = this.resultInfo;
3010                             try {
3011                                 this.resultInfo = resultInfoForClassDefinition;
3012                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
3013                                         dupLocalEnv, argtypes, typeargtypes, pkind);
3014                             } finally {
3015                                 this.resultInfo = prevResult;
3016                             }
3017                         });
3018             } else {
3019                 if (isDiamond && clazztype.hasTag(CLASS)) {
3020                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
3021                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
3022                         // One or more types inferred in the previous steps is non-denotable.
3023                         Fragment fragment = Diamond(clazztype.tsym);
3024                         log.error(tree.clazz.pos(),
3025                                 Errors.CantApplyDiamond1(
3026                                         fragment,
3027                                         invalidDiamondArgs.size() > 1 ?
3028                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
3029                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
3030                     }
3031                     // For <>(){}, inferred types must also be accessible.
3032                     for (Type t : clazztype.getTypeArguments()) {
3033                         rs.checkAccessibleType(env, t);
3034                     }
3035                 }
3036 
3037                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
3038                 // false for isInterface call even when the original type is an interface.
3039                 boolean implementing = clazztype.tsym.isInterface() ||
3040                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
3041                         clazztype.getOriginalType().tsym.isInterface();
3042 
3043                 if (implementing) {
3044                     cdef.implementing = List.of(clazz);
3045                 } else {
3046                     cdef.extending = clazz;
3047                 }
3048 
3049                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3050                     rs.isSerializable(clazztype)) {
3051                     localEnv.info.isSerializable = true;
3052                 }
3053 
3054                 attribStat(cdef, localEnv);
3055 
3056                 List<Type> finalargtypes;
3057                 // If an outer instance is given,
3058                 // prefix it to the constructor arguments
3059                 // and delete it from the new expression
3060                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
3061                     finalargtypes = argtypes.prepend(tree.encl.type);
3062                 } else {
3063                     finalargtypes = argtypes;
3064                 }
3065 
3066                 // Reassign clazztype and recompute constructor. As this necessarily involves
3067                 // another attribution pass for deferred types in the case of <>, replicate
3068                 // them. Original arguments have right decorations already.
3069                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3070                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3071                 }
3072 
3073                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3074                                                     : cdef.sym.type;
3075                 Symbol sym = tree.constructor = rs.resolveConstructor(
3076                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3077                 Assert.check(!sym.kind.isResolutionError());
3078                 tree.constructor = sym;
3079                 tree.constructorType = checkId(tree,
3080                         clazztype,
3081                         tree.constructor,
3082                         localEnv,
3083                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3084             }
3085             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3086                                 clazztype : types.createErrorType(tree.type);
3087             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3088             chk.validate(tree.typeargs, localEnv);
3089         }
3090 
3091         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3092             return new Check.NestedCheckContext(checkContext) {
3093                 @Override
3094                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3095                     enclosingContext.report(clazz.clazz,
3096                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3097                 }
3098             };
3099         }
3100 
3101         void checkNewInnerClass(DiagnosticPosition pos, Env<AttrContext> env, Type type, boolean isSuper) {
3102             boolean isLocal = type.tsym.owner.kind == VAR || type.tsym.owner.kind == MTH;
3103             if ((type.tsym.flags() & (INTERFACE | ENUM | RECORD)) != 0 ||
3104                     (!isLocal && !type.tsym.isInner()) ||
3105                     (isSuper && env.enclClass.sym.isAnonymous())) {
3106                 // nothing to check
3107                 return;
3108             }
3109             Symbol res = isLocal ?
3110                     rs.findLocalClassOwner(env, type.tsym) :
3111                     rs.findSelfContaining(pos, env, type.getEnclosingType().tsym, isSuper);
3112             if (res.exists()) {
3113                 rs.accessBase(res, pos, env.enclClass.sym.type, names._this, true);
3114             } else {
3115                 log.error(pos, Errors.EnclClassRequired(type.tsym));
3116             }
3117         }
3118 
3119     /** Make an attributed null check tree.
3120      */
3121     public JCExpression makeNullCheck(JCExpression arg) {
3122         // optimization: new Outer() can never be null; skip null check
3123         if (arg.getTag() == NEWCLASS)
3124             return arg;
3125         // optimization: X.this is never null; skip null check
3126         Name name = TreeInfo.name(arg);
3127         if (name == names._this || name == names._super) return arg;
3128 
3129         JCTree.Tag optag = NULLCHK;
3130         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3131         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3132         tree.type = arg.type;
3133         return tree;
3134     }
3135 
3136     public void visitNewArray(JCNewArray tree) {
3137         Type owntype = types.createErrorType(tree.type);
3138         Env<AttrContext> localEnv = env.dup(tree);
3139         Type elemtype;
3140         if (tree.elemtype != null) {
3141             elemtype = attribType(tree.elemtype, localEnv);
3142             chk.validate(tree.elemtype, localEnv);
3143             owntype = elemtype;
3144             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3145                 attribExpr(l.head, localEnv, syms.intType);
3146                 owntype = new ArrayType(owntype, syms.arrayClass);
3147             }
3148         } else {
3149             // we are seeing an untyped aggregate { ... }
3150             // this is allowed only if the prototype is an array
3151             if (pt().hasTag(ARRAY)) {
3152                 elemtype = types.elemtype(pt());
3153             } else {
3154                 if (!pt().hasTag(ERROR) &&
3155                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3156                     log.error(tree.pos(),
3157                               Errors.IllegalInitializerForType(pt()));
3158                 }
3159                 elemtype = types.createErrorType(pt());
3160             }
3161         }
3162         if (tree.elems != null) {
3163             attribExprs(tree.elems, localEnv, elemtype);
3164             owntype = new ArrayType(elemtype, syms.arrayClass);
3165         }
3166         if (!types.isReifiable(elemtype))
3167             log.error(tree.pos(), Errors.GenericArrayCreation);
3168         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3169     }
3170 
3171     /*
3172      * A lambda expression can only be attributed when a target-type is available.
3173      * In addition, if the target-type is that of a functional interface whose
3174      * descriptor contains inference variables in argument position the lambda expression
3175      * is 'stuck' (see DeferredAttr).
3176      */
3177     @Override
3178     public void visitLambda(final JCLambda that) {
3179         boolean wrongContext = false;
3180         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3181             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3182                 //lambda only allowed in assignment or method invocation/cast context
3183                 log.error(that.pos(), Errors.UnexpectedLambda);
3184             }
3185             resultInfo = recoveryInfo;
3186             wrongContext = true;
3187         }
3188         if (types.isQuoted(pt())) {
3189             attribQuotedLambda(that);
3190         } else {
3191             attribFunctionalLambda(that, wrongContext);
3192         }
3193     }
3194 
3195     void attribFunctionalLambda(JCLambda that, boolean wrongContext) {
3196         //create an environment for attribution of the lambda expression
3197         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3198         boolean needsRecovery =
3199                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3200         try {
3201             if (needsRecovery && rs.isSerializable(pt())) {
3202                 localEnv.info.isSerializable = true;
3203                 localEnv.info.isSerializableLambda = true;
3204             }
3205             List<Type> explicitParamTypes = null;
3206             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3207                 //attribute lambda parameters
3208                 attribStats(that.params, localEnv);
3209                 explicitParamTypes = TreeInfo.types(that.params);
3210             }
3211 
3212             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3213             Type currentTarget = targetInfo.target;
3214             Type lambdaType = targetInfo.descriptor;
3215 
3216             if (currentTarget.isErroneous()) {
3217                 result = that.type = currentTarget;
3218                 return;
3219             }
3220 
3221             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3222 
3223             if (lambdaType.hasTag(FORALL)) {
3224                 //lambda expression target desc cannot be a generic method
3225                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3226                                                                     kindName(currentTarget.tsym),
3227                                                                     currentTarget.tsym);
3228                 resultInfo.checkContext.report(that, diags.fragment(msg));
3229                 result = that.type = types.createErrorType(pt());
3230                 return;
3231             }
3232 
3233             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3234                 //add param type info in the AST
3235                 List<Type> actuals = lambdaType.getParameterTypes();
3236                 List<JCVariableDecl> params = that.params;
3237 
3238                 boolean arityMismatch = false;
3239 
3240                 while (params.nonEmpty()) {
3241                     if (actuals.isEmpty()) {
3242                         //not enough actuals to perform lambda parameter inference
3243                         arityMismatch = true;
3244                     }
3245                     //reset previously set info
3246                     Type argType = arityMismatch ?
3247                             syms.errType :
3248                             actuals.head;
3249                     if (params.head.isImplicitlyTyped()) {
3250                         setSyntheticVariableType(params.head, argType);
3251                     }
3252                     params.head.sym = null;
3253                     actuals = actuals.isEmpty() ?
3254                             actuals :
3255                             actuals.tail;
3256                     params = params.tail;
3257                 }
3258 
3259                 //attribute lambda parameters
3260                 attribStats(that.params, localEnv);
3261 
3262                 if (arityMismatch) {
3263                     resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3264                         result = that.type = types.createErrorType(currentTarget);
3265                         return;
3266                 }
3267             }
3268 
3269             //from this point on, no recovery is needed; if we are in assignment context
3270             //we will be able to attribute the whole lambda body, regardless of errors;
3271             //if we are in a 'check' method context, and the lambda is not compatible
3272             //with the target-type, it will be recovered anyway in Attr.checkId
3273             needsRecovery = false;
3274 
3275             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3276                     lambdaBodyResult(that, lambdaType, resultInfo);
3277 
3278             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3279                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3280             } else {
3281                 JCBlock body = (JCBlock)that.body;
3282                 if (body == breakTree &&
3283                         resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3284                     breakTreeFound(copyEnv(localEnv));
3285                 }
3286                 attribStats(body.stats, localEnv);
3287             }
3288 
3289             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3290 
3291             boolean isSpeculativeRound =
3292                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3293 
3294             preFlow(that);
3295             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3296 
3297             that.type = currentTarget; //avoids recovery at this stage
3298             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
3299 
3300             if (!isSpeculativeRound) {
3301                 //add thrown types as bounds to the thrown types free variables if needed:
3302                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3303                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3304                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3305                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3306                     }
3307                 }
3308 
3309                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3310             }
3311             result = wrongContext ? that.type = types.createErrorType(pt())
3312                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3313         } catch (Types.FunctionDescriptorLookupError ex) {
3314             JCDiagnostic cause = ex.getDiagnostic();
3315             resultInfo.checkContext.report(that, cause);
3316             result = that.type = types.createErrorType(pt());
3317             return;
3318         } catch (CompletionFailure cf) {
3319             chk.completionError(that.pos(), cf);
3320         } catch (Throwable t) {
3321             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3322             //as that would likely cause the same exception again.
3323             needsRecovery = false;
3324             throw t;
3325         } finally {
3326             localEnv.info.scope.leave();
3327             if (needsRecovery) {
3328                 Type prevResult = result;
3329                 try {
3330                     attribTree(that, env, recoveryInfo);
3331                 } finally {
3332                     if (result == Type.recoveryType) {
3333                         result = prevResult;
3334                     }
3335                 }
3336             }
3337         }
3338     }
3339 
3340     void attribQuotedLambda(JCLambda that) {
3341         // create an environment for attribution of the lambda expression
3342         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3343         try {
3344             // if quoted lambda is implicit, issue error, and recover
3345             if (that.paramKind == ParameterKind.IMPLICIT) {
3346                 log.error(that, Errors.QuotedLambdaMustBeExplicit);
3347                 // recovery
3348                 List<JCVariableDecl> params = that.params;
3349                 while (params.nonEmpty()) {
3350                     Type argType = syms.errType;
3351                     if (params.head.isImplicitlyTyped()) {
3352                         setSyntheticVariableType(params.head, argType);
3353                     }
3354                     params = params.tail;
3355                 }
3356             }
3357             // attribute lambda parameters
3358             attribStats(that.params, localEnv);
3359             List<Type> explicitParamTypes = TreeInfo.types(that.params);
3360 
3361             ListBuffer<Type> restypes = new ListBuffer<>();
3362             ListBuffer<DiagnosticPosition> resPositions = new ListBuffer<>();
3363             ResultInfo bodyResultInfo = localEnv.info.returnResult = unknownExprInfo;
3364 
3365             // type-check lambda body, and capture return types
3366             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3367                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3368                 restypes.add(checkQuotedReturnExpr((JCExpression) that.getBody()));
3369             } else {
3370                 JCBlock body = (JCBlock)that.body;
3371                 if (body == breakTree &&
3372                         resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3373                     breakTreeFound(copyEnv(localEnv));
3374                 }
3375                 attribStats(body.stats, localEnv);
3376                 new LambdaReturnScanner() {
3377                     @Override
3378                     public void visitReturn(JCReturn tree) {
3379                         if (tree.expr != null) {
3380                             resPositions.add(tree);
3381                         }
3382                         restypes.add(tree.expr == null ? syms.voidType : checkQuotedReturnExpr(tree.expr));
3383                     }
3384                 }.scan(body);
3385             }
3386 
3387             // check if lambda body can complete normally
3388             preFlow(that);
3389             flow.analyzeLambda(localEnv, that, make, false);
3390 
3391             final Type restype;
3392             boolean hasErroneousType = restypes.toList()
3393                     .stream().anyMatch(Type::isErroneous);
3394             if (that.getBodyKind() == BodyKind.STATEMENT) {
3395                 if (that.canCompleteNormally) {
3396                     // a lambda that completes normally has an implicit void return
3397                     restypes.add(syms.voidType);
3398                 }
3399 
3400                 if (hasErroneousType) {
3401                     restype = syms.errorType;
3402                 } else {
3403                     boolean hasNonVoidReturn = restypes.toList()
3404                             .stream().anyMatch(t -> t != syms.voidType);
3405                     boolean hasVoidReturn = restypes.toList()
3406                             .stream().anyMatch(t -> t == syms.voidType);
3407 
3408                     if (hasVoidReturn && hasNonVoidReturn) {
3409                         // void vs. non-void mismatch
3410                         log.error(that.body, Errors.CantInferQuotedLambdaReturnType(restypes.toList()));
3411                         restype = syms.errorType;
3412                     } else if (hasVoidReturn) {
3413                         restype = syms.voidType;
3414                     } else {
3415                         restype = condType(resPositions.toList(), restypes.toList());
3416                     }
3417                 }
3418             } else {
3419                 restype = restypes.first();
3420             }
3421 
3422             // infer lambda return type using lub
3423             if (!hasErroneousType && restype.hasTag(ERROR)) {
3424                 // some other error occurred
3425                 log.error(that.body, Errors.CantInferQuotedLambdaReturnType(restypes.toList()));
3426             }
3427 
3428             // infer thrown types
3429             List<Type> thrownTypes = flow.analyzeLambdaThrownTypes(localEnv, that, make);
3430 
3431             // set up target descriptor with explicit parameter types, and inferred thrown/return types
3432             that.target = new MethodType(explicitParamTypes, restype, thrownTypes, syms.methodClass);
3433             result = that.type = pt();
3434         } finally {
3435             localEnv.info.scope.leave();
3436         }
3437     }
3438     //where
3439         Type checkQuotedReturnExpr(JCExpression retExpr) {
3440             if (retExpr.type.hasTag(BOT)) {
3441                 log.error(retExpr, Errors.BadQuotedLambdaNullReturn);
3442             }
3443             return retExpr.type;
3444         }
3445 
3446 
3447         class TargetInfo {
3448             Type target;
3449             Type descriptor;
3450 
3451             public TargetInfo(Type target, Type descriptor) {
3452                 this.target = target;
3453                 this.descriptor = descriptor;
3454             }
3455         }
3456 
3457         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3458             Type lambdaType;
3459             Type currentTarget = resultInfo.pt;
3460             if (resultInfo.pt != Type.recoveryType) {
3461                 /* We need to adjust the target. If the target is an
3462                  * intersection type, for example: SAM & I1 & I2 ...
3463                  * the target will be updated to SAM
3464                  */
3465                 currentTarget = targetChecker.visit(currentTarget, that);
3466                 if (!currentTarget.isIntersection()) {
3467                     if (explicitParamTypes != null) {
3468                         currentTarget = infer.instantiateFunctionalInterface(that,
3469                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3470                     }
3471                     currentTarget = types.removeWildcards(currentTarget);
3472                     lambdaType = types.findDescriptorType(currentTarget);
3473                 } else {
3474                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3475                     ListBuffer<Type> components = new ListBuffer<>();
3476                     for (Type bound : ict.getExplicitComponents()) {
3477                         if (explicitParamTypes != null) {
3478                             try {
3479                                 bound = infer.instantiateFunctionalInterface(that,
3480                                         bound, explicitParamTypes, resultInfo.checkContext);
3481                             } catch (FunctionDescriptorLookupError t) {
3482                                 // do nothing
3483                             }
3484                         }
3485                         if (bound.tsym != syms.objectType.tsym && (!bound.isInterface() || (bound.tsym.flags() & ANNOTATION) != 0)) {
3486                             // bound must be j.l.Object or an interface, but not an annotation
3487                             reportIntersectionError(that, "not.an.intf.component", bound);
3488                         }
3489                         bound = types.removeWildcards(bound);
3490                         components.add(bound);
3491                     }
3492                     currentTarget = types.makeIntersectionType(components.toList());
3493                     currentTarget.tsym.flags_field |= INTERFACE;
3494                     lambdaType = types.findDescriptorType(currentTarget);
3495                 }
3496 
3497             } else {
3498                 currentTarget = Type.recoveryType;
3499                 lambdaType = fallbackDescriptorType(that);
3500             }
3501             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3502                 //lambda expression target desc cannot be a generic method
3503                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3504                                                                     kindName(currentTarget.tsym),
3505                                                                     currentTarget.tsym);
3506                 resultInfo.checkContext.report(that, diags.fragment(msg));
3507                 currentTarget = types.createErrorType(pt());
3508             }
3509             return new TargetInfo(currentTarget, lambdaType);
3510         }
3511 
3512         private void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) {
3513              resultInfo.checkContext.report(pos,
3514                  diags.fragment(Fragments.BadIntersectionTargetForFunctionalExpr(diags.fragment(key, args))));
3515         }
3516 
3517         void preFlow(JCLambda tree) {
3518             attrRecover.doRecovery();
3519             new PostAttrAnalyzer() {
3520                 @Override
3521                 public void scan(JCTree tree) {
3522                     if (tree == null ||
3523                             (tree.type != null &&
3524                             tree.type == Type.stuckType)) {
3525                         //don't touch stuck expressions!
3526                         return;
3527                     }
3528                     super.scan(tree);
3529                 }
3530 
3531                 @Override
3532                 public void visitClassDef(JCClassDecl that) {
3533                     // or class declaration trees!
3534                 }
3535 
3536                 public void visitLambda(JCLambda that) {
3537                     // or lambda expressions!
3538                 }
3539             }.scan(tree.body);
3540         }
3541 
3542         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3543 
3544             @Override
3545             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3546                 return t.isIntersection() ?
3547                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3548             }
3549 
3550             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3551                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3552                 return ict;
3553             }
3554 
3555             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3556                 ListBuffer<Type> targs = new ListBuffer<>();
3557                 ListBuffer<Type> supertypes = new ListBuffer<>();
3558                 for (Type i : ict.interfaces_field) {
3559                     if (i.isParameterized()) {
3560                         targs.appendList(i.tsym.type.allparams());
3561                     }
3562                     supertypes.append(i.tsym.type);
3563                 }
3564                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3565                 notionalIntf.allparams_field = targs.toList();
3566                 notionalIntf.tsym.flags_field |= INTERFACE;
3567                 return notionalIntf.tsym;
3568             }
3569         };
3570 
3571         private Type fallbackDescriptorType(JCExpression tree) {
3572             switch (tree.getTag()) {
3573                 case LAMBDA:
3574                     JCLambda lambda = (JCLambda)tree;
3575                     List<Type> argtypes = List.nil();
3576                     for (JCVariableDecl param : lambda.params) {
3577                         argtypes = param.vartype != null && param.vartype.type != null ?
3578                                 argtypes.append(param.vartype.type) :
3579                                 argtypes.append(syms.errType);
3580                     }
3581                     return new MethodType(argtypes, Type.recoveryType,
3582                             List.of(syms.throwableType), syms.methodClass);
3583                 case REFERENCE:
3584                     return new MethodType(List.nil(), Type.recoveryType,
3585                             List.of(syms.throwableType), syms.methodClass);
3586                 default:
3587                     Assert.error("Cannot get here!");
3588             }
3589             return null;
3590         }
3591 
3592         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3593                 final InferenceContext inferenceContext, final Type... ts) {
3594             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3595         }
3596 
3597         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3598                 final InferenceContext inferenceContext, final List<Type> ts) {
3599             if (inferenceContext.free(ts)) {
3600                 inferenceContext.addFreeTypeListener(ts,
3601                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3602             } else {
3603                 for (Type t : ts) {
3604                     rs.checkAccessibleType(env, t);
3605                 }
3606             }
3607         }
3608 
3609         /**
3610          * Lambda/method reference have a special check context that ensures
3611          * that i.e. a lambda return type is compatible with the expected
3612          * type according to both the inherited context and the assignment
3613          * context.
3614          */
3615         class FunctionalReturnContext extends Check.NestedCheckContext {
3616 
3617             FunctionalReturnContext(CheckContext enclosingContext) {
3618                 super(enclosingContext);
3619             }
3620 
3621             @Override
3622             public boolean compatible(Type found, Type req, Warner warn) {
3623                 //return type must be compatible in both current context and assignment context
3624                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3625             }
3626 
3627             @Override
3628             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3629                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3630             }
3631         }
3632 
3633         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3634 
3635             JCExpression expr;
3636             boolean expStmtExpected;
3637 
3638             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3639                 super(enclosingContext);
3640                 this.expr = expr;
3641             }
3642 
3643             @Override
3644             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3645                 if (expStmtExpected) {
3646                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3647                 } else {
3648                     super.report(pos, details);
3649                 }
3650             }
3651 
3652             @Override
3653             public boolean compatible(Type found, Type req, Warner warn) {
3654                 //a void return is compatible with an expression statement lambda
3655                 if (req.hasTag(VOID)) {
3656                     expStmtExpected = true;
3657                     return TreeInfo.isExpressionStatement(expr);
3658                 } else {
3659                     return super.compatible(found, req, warn);
3660                 }
3661             }
3662         }
3663 
3664         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3665             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3666                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3667                     new FunctionalReturnContext(resultInfo.checkContext);
3668 
3669             return descriptor.getReturnType() == Type.recoveryType ?
3670                     recoveryInfo :
3671                     new ResultInfo(KindSelector.VAL,
3672                             descriptor.getReturnType(), funcContext);
3673         }
3674 
3675         /**
3676         * Lambda compatibility. Check that given return types, thrown types, parameter types
3677         * are compatible with the expected functional interface descriptor. This means that:
3678         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3679         * types must be compatible with the return type of the expected descriptor.
3680         */
3681         void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
3682             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3683 
3684             //return values have already been checked - but if lambda has no return
3685             //values, we must ensure that void/value compatibility is correct;
3686             //this amounts at checking that, if a lambda body can complete normally,
3687             //the descriptor's return type must be void
3688             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3689                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3690                 Fragment msg =
3691                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3692                 checkContext.report(tree,
3693                                     diags.fragment(msg));
3694             }
3695 
3696             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3697             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3698                 checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3699             }
3700         }
3701 
3702         /* This method returns an environment to be used to attribute a lambda
3703          * expression.
3704          *
3705          * The owner of this environment is a method symbol. If the current owner
3706          * is not a method (e.g. if the lambda occurs in a field initializer), then
3707          * a synthetic method symbol owner is created.
3708          */
3709         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3710             Env<AttrContext> lambdaEnv;
3711             Symbol owner = env.info.scope.owner;
3712             if (owner.kind == VAR && owner.owner.kind == TYP) {
3713                 // If the lambda is nested in a field initializer, we need to create a fake init method.
3714                 // Uniqueness of this symbol is not important (as e.g. annotations will be added on the
3715                 // init symbol's owner).
3716                 ClassSymbol enclClass = owner.enclClass();
3717                 Name initName = owner.isStatic() ? names.clinit : names.init;
3718                 MethodSymbol initSym = new MethodSymbol(BLOCK | (owner.isStatic() ? STATIC : 0) | SYNTHETIC | PRIVATE,
3719                         initName, initBlockType, enclClass);
3720                 initSym.params = List.nil();
3721                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(initSym)));
3722             } else {
3723                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3724             }
3725             lambdaEnv.info.yieldResult = null;
3726             lambdaEnv.info.isLambda = true;
3727             return lambdaEnv;
3728         }
3729 
3730     @Override
3731     public void visitReference(final JCMemberReference that) {
3732         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3733             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3734                 //method reference only allowed in assignment or method invocation/cast context
3735                 log.error(that.pos(), Errors.UnexpectedMref);
3736             }
3737             result = that.type = types.createErrorType(pt());
3738             return;
3739         }
3740         final Env<AttrContext> localEnv = env.dup(that);
3741         try {
3742             //attribute member reference qualifier - if this is a constructor
3743             //reference, the expected kind must be a type
3744             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3745 
3746             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3747                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3748                 if (!exprType.isErroneous() &&
3749                     exprType.isRaw() &&
3750                     that.typeargs != null) {
3751                     log.error(that.expr.pos(),
3752                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3753                                                  Fragments.MrefInferAndExplicitParams));
3754                     exprType = types.createErrorType(exprType);
3755                 }
3756             }
3757 
3758             if (exprType.isErroneous()) {
3759                 //if the qualifier expression contains problems,
3760                 //give up attribution of method reference
3761                 result = that.type = exprType;
3762                 return;
3763             }
3764 
3765             if (TreeInfo.isStaticSelector(that.expr, names)) {
3766                 //if the qualifier is a type, validate it; raw warning check is
3767                 //omitted as we don't know at this stage as to whether this is a
3768                 //raw selector (because of inference)
3769                 chk.validate(that.expr, env, false);
3770             } else {
3771                 Symbol lhsSym = TreeInfo.symbol(that.expr);
3772                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
3773             }
3774             //attrib type-arguments
3775             List<Type> typeargtypes = List.nil();
3776             if (that.typeargs != null) {
3777                 typeargtypes = attribTypes(that.typeargs, localEnv);
3778             }
3779 
3780             boolean isTargetSerializable =
3781                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3782                     rs.isSerializable(pt());
3783             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
3784             Type currentTarget = targetInfo.target;
3785             Type desc = targetInfo.descriptor;
3786 
3787             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
3788             List<Type> argtypes = desc.getParameterTypes();
3789             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
3790 
3791             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
3792                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
3793             }
3794 
3795             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
3796             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
3797             try {
3798                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
3799                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
3800                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
3801             } finally {
3802                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
3803             }
3804 
3805             Symbol refSym = refResult.fst;
3806             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
3807 
3808             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
3809              *  JDK-8075541
3810              */
3811             if (refSym.kind != MTH) {
3812                 boolean targetError;
3813                 switch (refSym.kind) {
3814                     case ABSENT_MTH:
3815                         targetError = false;
3816                         break;
3817                     case WRONG_MTH:
3818                     case WRONG_MTHS:
3819                     case AMBIGUOUS:
3820                     case HIDDEN:
3821                     case STATICERR:
3822                         targetError = true;
3823                         break;
3824                     default:
3825                         Assert.error("unexpected result kind " + refSym.kind);
3826                         targetError = false;
3827                 }
3828 
3829                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
3830                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
3831                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
3832 
3833                 JCDiagnostic diag = diags.create(log.currentSource(), that,
3834                         targetError ?
3835                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
3836                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
3837 
3838                 if (targetError && currentTarget == Type.recoveryType) {
3839                     //a target error doesn't make sense during recovery stage
3840                     //as we don't know what actual parameter types are
3841                     result = that.type = currentTarget;
3842                     return;
3843                 } else {
3844                     if (targetError) {
3845                         resultInfo.checkContext.report(that, diag);
3846                     } else {
3847                         log.report(diag);
3848                     }
3849                     result = that.type = types.createErrorType(currentTarget);
3850                     return;
3851                 }
3852             }
3853 
3854             that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
3855             that.kind = lookupHelper.referenceKind(that.sym);
3856             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
3857 
3858             if (desc.getReturnType() == Type.recoveryType) {
3859                 // stop here
3860                 result = that.type = currentTarget;
3861                 return;
3862             }
3863 
3864             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3865                 checkNewInnerClass(that.pos(), env, exprType, false);
3866             }
3867 
3868             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3869 
3870                 if (that.getMode() == ReferenceMode.INVOKE &&
3871                         TreeInfo.isStaticSelector(that.expr, names) &&
3872                         that.kind.isUnbound() &&
3873                         lookupHelper.site.isRaw()) {
3874                     chk.checkRaw(that.expr, localEnv);
3875                 }
3876 
3877                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
3878                         exprType.getTypeArguments().nonEmpty()) {
3879                     //static ref with class type-args
3880                     log.error(that.expr.pos(),
3881                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3882                                                  Fragments.StaticMrefWithTargs));
3883                     result = that.type = types.createErrorType(currentTarget);
3884                     return;
3885                 }
3886 
3887                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
3888                     // Check that super-qualified symbols are not abstract (JLS)
3889                     rs.checkNonAbstract(that.pos(), that.sym);
3890                 }
3891 
3892                 if (isTargetSerializable) {
3893                     chk.checkAccessFromSerializableElement(that, true);
3894                 }
3895             }
3896 
3897             ResultInfo checkInfo =
3898                     resultInfo.dup(newMethodTemplate(
3899                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
3900                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
3901                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3902 
3903             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
3904 
3905             if (that.kind.isUnbound() &&
3906                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
3907                 //re-generate inference constraints for unbound receiver
3908                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
3909                     //cannot happen as this has already been checked - we just need
3910                     //to regenerate the inference constraints, as that has been lost
3911                     //as a result of the call to inferenceContext.save()
3912                     Assert.error("Can't get here");
3913                 }
3914             }
3915 
3916             if (!refType.isErroneous()) {
3917                 refType = types.createMethodTypeWithReturn(refType,
3918                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
3919             }
3920 
3921             //go ahead with standard method reference compatibility check - note that param check
3922             //is a no-op (as this has been taken care during method applicability)
3923             boolean isSpeculativeRound =
3924                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3925 
3926             that.type = currentTarget; //avoids recovery at this stage
3927             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
3928             if (!isSpeculativeRound) {
3929                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
3930             }
3931             chk.checkRequiresIdentity(that, localEnv.info.lint);
3932             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3933         } catch (Types.FunctionDescriptorLookupError ex) {
3934             JCDiagnostic cause = ex.getDiagnostic();
3935             resultInfo.checkContext.report(that, cause);
3936             result = that.type = types.createErrorType(pt());
3937             return;
3938         }
3939     }
3940     //where
3941         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
3942             //if this is a constructor reference, the expected kind must be a type
3943             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
3944                                   KindSelector.VAL_TYP : KindSelector.TYP,
3945                                   Type.noType);
3946         }
3947 
3948 
3949     @SuppressWarnings("fallthrough")
3950     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
3951         InferenceContext inferenceContext = checkContext.inferenceContext();
3952         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
3953 
3954         Type resType;
3955         switch (tree.getMode()) {
3956             case NEW:
3957                 if (!tree.expr.type.isRaw()) {
3958                     resType = tree.expr.type;
3959                     break;
3960                 }
3961             default:
3962                 resType = refType.getReturnType();
3963         }
3964 
3965         Type incompatibleReturnType = resType;
3966 
3967         if (returnType.hasTag(VOID)) {
3968             incompatibleReturnType = null;
3969         }
3970 
3971         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
3972             if (resType.isErroneous() ||
3973                     new FunctionalReturnContext(checkContext).compatible(resType, returnType,
3974                             checkContext.checkWarner(tree, resType, returnType))) {
3975                 incompatibleReturnType = null;
3976             }
3977         }
3978 
3979         if (incompatibleReturnType != null) {
3980             Fragment msg =
3981                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
3982             checkContext.report(tree, diags.fragment(msg));
3983         } else {
3984             if (inferenceContext.free(refType)) {
3985                 // we need to wait for inference to finish and then replace inference vars in the referent type
3986                 inferenceContext.addFreeTypeListener(List.of(refType),
3987                         instantiatedContext -> {
3988                             tree.referentType = instantiatedContext.asInstType(refType);
3989                         });
3990             } else {
3991                 tree.referentType = refType;
3992             }
3993         }
3994 
3995         if (!speculativeAttr) {
3996             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
3997                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
3998             }
3999         }
4000     }
4001 
4002     boolean checkExConstraints(
4003             List<Type> thrownByFuncExpr,
4004             List<Type> thrownAtFuncType,
4005             InferenceContext inferenceContext) {
4006         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
4007          *  are not proper types
4008          */
4009         List<Type> nonProperList = thrownAtFuncType.stream()
4010                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
4011         List<Type> properList = thrownAtFuncType.diff(nonProperList);
4012 
4013         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
4014          *  in the throws clause of the invocation type of the method reference's compile-time
4015          *  declaration
4016          */
4017         List<Type> checkedList = thrownByFuncExpr.stream()
4018                 .filter(e -> chk.isChecked(e)).collect(List.collector());
4019 
4020         /** If n = 0 (the function type's throws clause consists only of proper types), then
4021          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
4022          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
4023          *  reduces to true
4024          */
4025         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
4026         for (Type checked : checkedList) {
4027             boolean isSubtype = false;
4028             for (Type proper : properList) {
4029                 if (types.isSubtype(checked, proper)) {
4030                     isSubtype = true;
4031                     break;
4032                 }
4033             }
4034             if (!isSubtype) {
4035                 uncaughtByProperTypes.add(checked);
4036             }
4037         }
4038 
4039         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
4040             return false;
4041         }
4042 
4043         /** If n > 0, the constraint reduces to a set of subtyping constraints:
4044          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
4045          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
4046          */
4047         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
4048         uncaughtByProperTypes.forEach(checkedEx -> {
4049             nonProperAsUndet.forEach(nonProper -> {
4050                 types.isSubtype(checkedEx, nonProper);
4051             });
4052         });
4053 
4054         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
4055          */
4056         nonProperAsUndet.stream()
4057                 .filter(t -> t.hasTag(UNDETVAR))
4058                 .forEach(t -> ((UndetVar)t).setThrow());
4059         return true;
4060     }
4061 
4062     /**
4063      * Set functional type info on the underlying AST. Note: as the target descriptor
4064      * might contain inference variables, we might need to register an hook in the
4065      * current inference context.
4066      */
4067     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
4068             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
4069         if (checkContext.inferenceContext().free(descriptorType)) {
4070             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
4071                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
4072                     inferenceContext.asInstType(primaryTarget), checkContext));
4073         } else {
4074             fExpr.owner = env.info.scope.owner;
4075             if (pt.hasTag(CLASS)) {
4076                 fExpr.target = primaryTarget;
4077             }
4078             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
4079                     pt != Type.recoveryType) {
4080                 //check that functional interface class is well-formed
4081                 try {
4082                     /* Types.makeFunctionalInterfaceClass() may throw an exception
4083                      * when it's executed post-inference. See the listener code
4084                      * above.
4085                      */
4086                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
4087                             names.empty, fExpr.target, ABSTRACT);
4088                     if (csym != null) {
4089                         chk.checkImplementations(env.tree, csym, csym);
4090                         try {
4091                             //perform an additional functional interface check on the synthetic class,
4092                             //as there may be spurious errors for raw targets - because of existing issues
4093                             //with membership and inheritance (see JDK-8074570).
4094                             csym.flags_field |= INTERFACE;
4095                             types.findDescriptorType(csym.type);
4096                         } catch (FunctionDescriptorLookupError err) {
4097                             resultInfo.checkContext.report(fExpr,
4098                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
4099                         }
4100                     }
4101                 } catch (Types.FunctionDescriptorLookupError ex) {
4102                     JCDiagnostic cause = ex.getDiagnostic();
4103                     resultInfo.checkContext.report(env.tree, cause);
4104                 }
4105             }
4106         }
4107     }
4108 
4109     public void visitParens(JCParens tree) {
4110         Type owntype = attribTree(tree.expr, env, resultInfo);
4111         result = check(tree, owntype, pkind(), resultInfo);
4112         Symbol sym = TreeInfo.symbol(tree);
4113         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
4114             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
4115     }
4116 
4117     public void visitAssign(JCAssign tree) {
4118         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
4119         Type capturedType = capture(owntype);
4120         attribExpr(tree.rhs, env, owntype);
4121         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
4122     }
4123 
4124     public void visitAssignop(JCAssignOp tree) {
4125         // Attribute arguments.
4126         Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
4127         Type operand = attribExpr(tree.rhs, env);
4128         // Find operator.
4129         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
4130         if (operator != operators.noOpSymbol &&
4131                 !owntype.isErroneous() &&
4132                 !operand.isErroneous()) {
4133             chk.checkDivZero(tree.rhs.pos(), operator, operand);
4134             chk.checkCastable(tree.rhs.pos(),
4135                               operator.type.getReturnType(),
4136                               owntype);
4137             chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
4138         }
4139         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4140     }
4141 
4142     public void visitUnary(JCUnary tree) {
4143         // Attribute arguments.
4144         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
4145             ? attribTree(tree.arg, env, varAssignmentInfo)
4146             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
4147 
4148         // Find operator.
4149         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
4150         Type owntype = types.createErrorType(tree.type);
4151         if (operator != operators.noOpSymbol &&
4152                 !argtype.isErroneous()) {
4153             owntype = (tree.getTag().isIncOrDecUnaryOp())
4154                 ? tree.arg.type
4155                 : operator.type.getReturnType();
4156             int opc = operator.opcode;
4157 
4158             // If the argument is constant, fold it.
4159             if (argtype.constValue() != null) {
4160                 Type ctype = cfolder.fold1(opc, argtype);
4161                 if (ctype != null) {
4162                     owntype = cfolder.coerce(ctype, owntype);
4163                 }
4164             }
4165         }
4166         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4167         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4168     }
4169 
4170     public void visitBinary(JCBinary tree) {
4171         // Attribute arguments.
4172         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4173         // x && y
4174         // include x's bindings when true in y
4175 
4176         // x || y
4177         // include x's bindings when false in y
4178 
4179         MatchBindings lhsBindings = matchBindings;
4180         List<BindingSymbol> propagatedBindings;
4181         switch (tree.getTag()) {
4182             case AND:
4183                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4184                 break;
4185             case OR:
4186                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4187                 break;
4188             default:
4189                 propagatedBindings = List.nil();
4190                 break;
4191         }
4192         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4193         Type right;
4194         try {
4195             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4196         } finally {
4197             rhsEnv.info.scope.leave();
4198         }
4199 
4200         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4201 
4202         // Find operator.
4203         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4204         Type owntype = types.createErrorType(tree.type);
4205         if (operator != operators.noOpSymbol &&
4206                 !left.isErroneous() &&
4207                 !right.isErroneous()) {
4208             owntype = operator.type.getReturnType();
4209             int opc = operator.opcode;
4210             // If both arguments are constants, fold them.
4211             if (left.constValue() != null && right.constValue() != null) {
4212                 Type ctype = cfolder.fold2(opc, left, right);
4213                 if (ctype != null) {
4214                     owntype = cfolder.coerce(ctype, owntype);
4215                 }
4216             }
4217 
4218             // Check that argument types of a reference ==, != are
4219             // castable to each other, (JLS 15.21).  Note: unboxing
4220             // comparisons will not have an acmp* opc at this point.
4221             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4222                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4223                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4224                 }
4225             }
4226 
4227             chk.checkDivZero(tree.rhs.pos(), operator, right);
4228         }
4229         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4230     }
4231 
4232     public void visitTypeCast(final JCTypeCast tree) {
4233         Type clazztype = attribType(tree.clazz, env);
4234         chk.validate(tree.clazz, env, false);
4235         chk.checkRequiresIdentity(tree, env.info.lint);
4236         //a fresh environment is required for 292 inference to work properly ---
4237         //see Infer.instantiatePolymorphicSignatureInstance()
4238         Env<AttrContext> localEnv = env.dup(tree);
4239         //should we propagate the target type?
4240         final ResultInfo castInfo;
4241         JCExpression expr = TreeInfo.skipParens(tree.expr);
4242         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4243         if (isPoly) {
4244             //expression is a poly - we need to propagate target type info
4245             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4246                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4247                 @Override
4248                 public boolean compatible(Type found, Type req, Warner warn) {
4249                     return types.isCastable(found, req, warn);
4250                 }
4251             });
4252         } else {
4253             //standalone cast - target-type info is not propagated
4254             castInfo = unknownExprInfo;
4255         }
4256         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4257         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4258         if (exprtype.constValue() != null)
4259             owntype = cfolder.coerce(exprtype, owntype);
4260         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4261         if (!isPoly)
4262             chk.checkRedundantCast(localEnv, tree);
4263     }
4264 
4265     public void visitTypeTest(JCInstanceOf tree) {
4266         Type exprtype = attribExpr(tree.expr, env);
4267         if (exprtype.isPrimitive()) {
4268             preview.checkSourceLevel(tree.expr.pos(), Feature.PRIMITIVE_PATTERNS);
4269         } else {
4270             exprtype = chk.checkNullOrRefType(
4271                     tree.expr.pos(), exprtype);
4272         }
4273         Type clazztype;
4274         JCTree typeTree;
4275         if (tree.pattern.getTag() == BINDINGPATTERN ||
4276             tree.pattern.getTag() == RECORDPATTERN) {
4277             attribExpr(tree.pattern, env, exprtype);
4278             clazztype = tree.pattern.type;
4279             if (types.isSubtype(exprtype, clazztype) &&
4280                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4281                 tree.pattern.getTag() != RECORDPATTERN) {
4282                 if (!allowUnconditionalPatternsInstanceOf) {
4283                     log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(),
4284                               Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.error(this.sourceName));
4285                 }
4286             }
4287             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4288         } else {
4289             clazztype = attribType(tree.pattern, env);
4290             typeTree = tree.pattern;
4291             chk.validate(typeTree, env, false);
4292         }
4293         if (clazztype.isPrimitive()) {
4294             preview.checkSourceLevel(tree.pattern.pos(), Feature.PRIMITIVE_PATTERNS);
4295         } else {
4296             if (!clazztype.hasTag(TYPEVAR)) {
4297                 clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4298             }
4299             if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4300                 boolean valid = false;
4301                 if (allowReifiableTypesInInstanceof) {
4302                     valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4303                 } else {
4304                     log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(),
4305                             Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4306                     allowReifiableTypesInInstanceof = true;
4307                 }
4308                 if (!valid) {
4309                     clazztype = types.createErrorType(clazztype);
4310                 }
4311             }
4312         }
4313         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4314         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4315     }
4316 
4317     private boolean checkCastablePattern(DiagnosticPosition pos,
4318                                          Type exprType,
4319                                          Type pattType) {
4320         Warner warner = new Warner();
4321         // if any type is erroneous, the problem is reported elsewhere
4322         if (exprType.isErroneous() || pattType.isErroneous()) {
4323             return false;
4324         }
4325         if (!types.isCastable(exprType, pattType, warner)) {
4326             chk.basicHandler.report(pos,
4327                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4328             return false;
4329         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4330                 (!exprType.isPrimitive() || !pattType.isPrimitive() || !types.isSameType(exprType, pattType))) {
4331             preview.checkSourceLevel(pos, Feature.PRIMITIVE_PATTERNS);
4332             return true;
4333         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4334             log.error(pos,
4335                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4336             return false;
4337         } else {
4338             return true;
4339         }
4340     }
4341 
4342     @Override
4343     public void visitAnyPattern(JCAnyPattern tree) {
4344         result = tree.type = resultInfo.pt;
4345     }
4346 
4347     public void visitBindingPattern(JCBindingPattern tree) {
4348         Type type;
4349         if (tree.var.vartype != null) {
4350             type = attribType(tree.var.vartype, env);
4351         } else {
4352             type = resultInfo.pt;
4353         }
4354         tree.type = tree.var.type = type;
4355         BindingSymbol v = new BindingSymbol(tree.var.mods.flags, tree.var.name, type, env.info.scope.owner);
4356         v.pos = tree.pos;
4357         tree.var.sym = v;
4358         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4359             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4360         }
4361         chk.validate(tree.var.vartype, env, true);
4362         if (tree.var.isImplicitlyTyped()) {
4363             setSyntheticVariableType(tree.var, type == Type.noType ? syms.errType
4364                                                                    : type);
4365         }
4366         annotate.annotateLater(tree.var.mods.annotations, env, v, tree.var);
4367         if (!tree.var.isImplicitlyTyped()) {
4368             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v, tree.var);
4369         }
4370         annotate.flush();
4371         result = tree.type;
4372         if (v.isUnnamedVariable()) {
4373             matchBindings = MatchBindingsComputer.EMPTY;
4374         } else {
4375             matchBindings = new MatchBindings(List.of(v), List.nil());
4376         }
4377         chk.checkRequiresIdentity(tree, env.info.lint);
4378     }
4379 
4380     @Override
4381     public void visitRecordPattern(JCRecordPattern tree) {
4382         Type site;
4383 
4384         if (tree.deconstructor == null) {
4385             log.error(tree.pos(), Errors.DeconstructionPatternVarNotAllowed);
4386             tree.record = syms.errSymbol;
4387             site = tree.type = types.createErrorType(tree.record.type);
4388         } else {
4389             Type type = attribType(tree.deconstructor, env);
4390             if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4391                 Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4392                 if (inferred == null) {
4393                     log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4394                 } else {
4395                     type = inferred;
4396                 }
4397             }
4398             tree.type = tree.deconstructor.type = type;
4399             site = types.capture(tree.type);
4400         }
4401 
4402         List<Type> expectedRecordTypes;
4403         if (site.tsym.kind == Kind.TYP && ((ClassSymbol) site.tsym).isRecord()) {
4404             ClassSymbol record = (ClassSymbol) site.tsym;
4405             expectedRecordTypes = record.getRecordComponents()
4406                                         .stream()
4407                                         .map(rc -> types.memberType(site, rc))
4408                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4409                                         .collect(List.collector());
4410             tree.record = record;
4411         } else {
4412             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4413             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4414                                 .limit(tree.nested.size())
4415                                 .collect(List.collector());
4416             tree.record = syms.errSymbol;
4417         }
4418         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4419         List<Type> recordTypes = expectedRecordTypes;
4420         List<JCPattern> nestedPatterns = tree.nested;
4421         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4422         try {
4423             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4424                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4425                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4426                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4427                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4428                 nestedPatterns = nestedPatterns.tail;
4429                 recordTypes = recordTypes.tail;
4430             }
4431             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4432                 while (nestedPatterns.nonEmpty()) {
4433                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4434                     nestedPatterns = nestedPatterns.tail;
4435                 }
4436                 List<Type> nestedTypes =
4437                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4438                 log.error(tree.pos(),
4439                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4440                                                                  nestedTypes));
4441             }
4442         } finally {
4443             localEnv.info.scope.leave();
4444         }
4445         chk.validate(tree.deconstructor, env, true);
4446         result = tree.type;
4447         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4448     }
4449 
4450     public void visitIndexed(JCArrayAccess tree) {
4451         Type owntype = types.createErrorType(tree.type);
4452         Type atype = attribExpr(tree.indexed, env);
4453         attribExpr(tree.index, env, syms.intType);
4454         if (types.isArray(atype))
4455             owntype = types.elemtype(atype);
4456         else if (!atype.hasTag(ERROR))
4457             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4458         if (!pkind().contains(KindSelector.VAL))
4459             owntype = capture(owntype);
4460         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4461     }
4462 
4463     public void visitIdent(JCIdent tree) {
4464         Symbol sym;
4465 
4466         // Find symbol
4467         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4468             // If we are looking for a method, the prototype `pt' will be a
4469             // method type with the type of the call's arguments as parameters.
4470             env.info.pendingResolutionPhase = null;
4471             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4472         } else if (tree.sym != null && tree.sym.kind != VAR) {
4473             sym = tree.sym;
4474         } else {
4475             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4476         }
4477         tree.sym = sym;
4478 
4479         // Also find the environment current for the class where
4480         // sym is defined (`symEnv').
4481         Env<AttrContext> symEnv = env;
4482         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4483             sym.kind.matches(KindSelector.VAL_MTH) &&
4484             sym.owner.kind == TYP &&
4485             tree.name != names._this && tree.name != names._super) {
4486 
4487             // Find environment in which identifier is defined.
4488             while (symEnv.outer != null &&
4489                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4490                 symEnv = symEnv.outer;
4491             }
4492         }
4493 
4494         // If symbol is a variable, ...
4495         if (sym.kind == VAR) {
4496             VarSymbol v = (VarSymbol)sym;
4497 
4498             // ..., evaluate its initializer, if it has one, and check for
4499             // illegal forward reference.
4500             checkInit(tree, env, v, false);
4501 
4502             // If we are expecting a variable (as opposed to a value), check
4503             // that the variable is assignable in the current environment.
4504             if (KindSelector.ASG.subset(pkind()))
4505                 checkAssignable(tree.pos(), v, null, env);
4506         }
4507 
4508         Env<AttrContext> env1 = env;
4509         if (sym.kind != ERR && sym.kind != TYP &&
4510             sym.owner != null && sym.owner != env1.enclClass.sym) {
4511             // If the found symbol is inaccessible, then it is
4512             // accessed through an enclosing instance.  Locate this
4513             // enclosing instance:
4514             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4515                 env1 = env1.outer;
4516         }
4517 
4518         if (env.info.isSerializable) {
4519             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4520         }
4521 
4522         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4523     }
4524 
4525     public void visitSelect(JCFieldAccess tree) {
4526         // Determine the expected kind of the qualifier expression.
4527         KindSelector skind = KindSelector.NIL;
4528         if (tree.name == names._this || tree.name == names._super ||
4529                 tree.name == names._class)
4530         {
4531             skind = KindSelector.TYP;
4532         } else {
4533             if (pkind().contains(KindSelector.PCK))
4534                 skind = KindSelector.of(skind, KindSelector.PCK);
4535             if (pkind().contains(KindSelector.TYP))
4536                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4537             if (pkind().contains(KindSelector.VAL_MTH))
4538                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4539         }
4540 
4541         // Attribute the qualifier expression, and determine its symbol (if any).
4542         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
4543         if (!pkind().contains(KindSelector.TYP_PCK))
4544             site = capture(site); // Capture field access
4545 
4546         // don't allow T.class T[].class, etc
4547         if (skind == KindSelector.TYP) {
4548             Type elt = site;
4549             while (elt.hasTag(ARRAY))
4550                 elt = ((ArrayType)elt).elemtype;
4551             if (elt.hasTag(TYPEVAR)) {
4552                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4553                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4554                 tree.sym = tree.type.tsym;
4555                 return ;
4556             }
4557         }
4558 
4559         // If qualifier symbol is a type or `super', assert `selectSuper'
4560         // for the selection. This is relevant for determining whether
4561         // protected symbols are accessible.
4562         Symbol sitesym = TreeInfo.symbol(tree.selected);
4563         boolean selectSuperPrev = env.info.selectSuper;
4564         env.info.selectSuper =
4565             sitesym != null &&
4566             sitesym.name == names._super;
4567 
4568         // Determine the symbol represented by the selection.
4569         env.info.pendingResolutionPhase = null;
4570         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
4571         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4572             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4573             sym = syms.errSymbol;
4574         }
4575         if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
4576             site = capture(site);
4577             sym = selectSym(tree, sitesym, site, env, resultInfo);
4578         }
4579         boolean varArgs = env.info.lastResolveVarargs();
4580         tree.sym = sym;
4581 
4582         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4583             site = types.skipTypeVars(site, true);
4584         }
4585 
4586         // If that symbol is a variable, ...
4587         if (sym.kind == VAR) {
4588             VarSymbol v = (VarSymbol)sym;
4589 
4590             // ..., evaluate its initializer, if it has one, and check for
4591             // illegal forward reference.
4592             checkInit(tree, env, v, true);
4593 
4594             // If we are expecting a variable (as opposed to a value), check
4595             // that the variable is assignable in the current environment.
4596             if (KindSelector.ASG.subset(pkind()))
4597                 checkAssignable(tree.pos(), v, tree.selected, env);
4598         }
4599 
4600         if (sitesym != null &&
4601                 sitesym.kind == VAR &&
4602                 ((VarSymbol)sitesym).isResourceVariable() &&
4603                 sym.kind == MTH &&
4604                 sym.name.equals(names.close) &&
4605                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true)) {
4606             env.info.lint.logIfEnabled(tree, LintWarnings.TryExplicitCloseCall);
4607         }
4608 
4609         // Disallow selecting a type from an expression
4610         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4611             tree.type = check(tree.selected, pt(),
4612                               sitesym == null ?
4613                                       KindSelector.VAL : sitesym.kind.toSelector(),
4614                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4615         }
4616 
4617         if (isType(sitesym)) {
4618             if (sym.name != names._this && sym.name != names._super) {
4619                 // Check if type-qualified fields or methods are static (JLS)
4620                 if ((sym.flags() & STATIC) == 0 &&
4621                     sym.name != names._super &&
4622                     (sym.kind == VAR || sym.kind == MTH)) {
4623                     rs.accessBase(rs.new StaticError(sym),
4624                               tree.pos(), site, sym.name, true);
4625                 }
4626             }
4627         } else if (sym.kind != ERR &&
4628                    (sym.flags() & STATIC) != 0 &&
4629                    sym.name != names._class) {
4630             // If the qualified item is not a type and the selected item is static, report
4631             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4632             if (!sym.owner.isAnonymous()) {
4633                 chk.lint.logIfEnabled(tree, LintWarnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4634             } else {
4635                 chk.lint.logIfEnabled(tree, LintWarnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4636             }
4637         }
4638 
4639         // If we are selecting an instance member via a `super', ...
4640         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4641 
4642             // Check that super-qualified symbols are not abstract (JLS)
4643             rs.checkNonAbstract(tree.pos(), sym);
4644 
4645             if (site.isRaw()) {
4646                 // Determine argument types for site.
4647                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
4648                 if (site1 != null) site = site1;
4649             }
4650         }
4651 
4652         if (env.info.isSerializable) {
4653             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4654         }
4655 
4656         env.info.selectSuper = selectSuperPrev;
4657         result = checkId(tree, site, sym, env, resultInfo);
4658     }
4659     //where
4660         /** Determine symbol referenced by a Select expression,
4661          *
4662          *  @param tree   The select tree.
4663          *  @param site   The type of the selected expression,
4664          *  @param env    The current environment.
4665          *  @param resultInfo The current result.
4666          */
4667         private Symbol selectSym(JCFieldAccess tree,
4668                                  Symbol location,
4669                                  Type site,
4670                                  Env<AttrContext> env,
4671                                  ResultInfo resultInfo) {
4672             DiagnosticPosition pos = tree.pos();
4673             Name name = tree.name;
4674             switch (site.getTag()) {
4675             case PACKAGE:
4676                 return rs.accessBase(
4677                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4678                     pos, location, site, name, true);
4679             case ARRAY:
4680             case CLASS:
4681                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4682                     return rs.resolveQualifiedMethod(
4683                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4684                 } else if (name == names._this || name == names._super) {
4685                     return rs.resolveSelf(pos, env, site.tsym, tree);
4686                 } else if (name == names._class) {
4687                     // In this case, we have already made sure in
4688                     // visitSelect that qualifier expression is a type.
4689                     return syms.getClassField(site, types);
4690                 } else {
4691                     // We are seeing a plain identifier as selector.
4692                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
4693                         sym = rs.accessBase(sym, pos, location, site, name, true);
4694                     return sym;
4695                 }
4696             case WILDCARD:
4697                 throw new AssertionError(tree);
4698             case TYPEVAR:
4699                 // Normally, site.getUpperBound() shouldn't be null.
4700                 // It should only happen during memberEnter/attribBase
4701                 // when determining the supertype which *must* be
4702                 // done before attributing the type variables.  In
4703                 // other words, we are seeing this illegal program:
4704                 // class B<T> extends A<T.foo> {}
4705                 Symbol sym = (site.getUpperBound() != null)
4706                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
4707                     : null;
4708                 if (sym == null) {
4709                     log.error(pos, Errors.TypeVarCantBeDeref);
4710                     return syms.errSymbol;
4711                 } else {
4712                     Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
4713                         rs.new AccessError(env, site, sym) :
4714                                 sym;
4715                     rs.accessBase(sym2, pos, location, site, name, true);
4716                     return sym;
4717                 }
4718             case ERROR:
4719                 // preserve identifier names through errors
4720                 return types.createErrorType(name, site.tsym, site).tsym;
4721             default:
4722                 // The qualifier expression is of a primitive type -- only
4723                 // .class is allowed for these.
4724                 if (name == names._class) {
4725                     // In this case, we have already made sure in Select that
4726                     // qualifier expression is a type.
4727                     return syms.getClassField(site, types);
4728                 } else {
4729                     log.error(pos, Errors.CantDeref(site));
4730                     return syms.errSymbol;
4731                 }
4732             }
4733         }
4734 
4735         /** Determine type of identifier or select expression and check that
4736          *  (1) the referenced symbol is not deprecated
4737          *  (2) the symbol's type is safe (@see checkSafe)
4738          *  (3) if symbol is a variable, check that its type and kind are
4739          *      compatible with the prototype and protokind.
4740          *  (4) if symbol is an instance field of a raw type,
4741          *      which is being assigned to, issue an unchecked warning if its
4742          *      type changes under erasure.
4743          *  (5) if symbol is an instance method of a raw type, issue an
4744          *      unchecked warning if its argument types change under erasure.
4745          *  If checks succeed:
4746          *    If symbol is a constant, return its constant type
4747          *    else if symbol is a method, return its result type
4748          *    otherwise return its type.
4749          *  Otherwise return errType.
4750          *
4751          *  @param tree       The syntax tree representing the identifier
4752          *  @param site       If this is a select, the type of the selected
4753          *                    expression, otherwise the type of the current class.
4754          *  @param sym        The symbol representing the identifier.
4755          *  @param env        The current environment.
4756          *  @param resultInfo    The expected result
4757          */
4758         Type checkId(JCTree tree,
4759                      Type site,
4760                      Symbol sym,
4761                      Env<AttrContext> env,
4762                      ResultInfo resultInfo) {
4763             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
4764                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
4765                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4766         }
4767 
4768         Type checkMethodIdInternal(JCTree tree,
4769                      Type site,
4770                      Symbol sym,
4771                      Env<AttrContext> env,
4772                      ResultInfo resultInfo) {
4773             if (resultInfo.pkind.contains(KindSelector.POLY)) {
4774                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
4775             } else {
4776                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
4777             }
4778         }
4779 
4780         Type checkIdInternal(JCTree tree,
4781                      Type site,
4782                      Symbol sym,
4783                      Type pt,
4784                      Env<AttrContext> env,
4785                      ResultInfo resultInfo) {
4786             Type owntype; // The computed type of this identifier occurrence.
4787             switch (sym.kind) {
4788             case TYP:
4789                 // For types, the computed type equals the symbol's type,
4790                 // except for two situations:
4791                 owntype = sym.type;
4792                 if (owntype.hasTag(CLASS)) {
4793                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
4794                     Type ownOuter = owntype.getEnclosingType();
4795 
4796                     // (a) If the symbol's type is parameterized, erase it
4797                     // because no type parameters were given.
4798                     // We recover generic outer type later in visitTypeApply.
4799                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
4800                         owntype = types.erasure(owntype);
4801                     }
4802 
4803                     // (b) If the symbol's type is an inner class, then
4804                     // we have to interpret its outer type as a superclass
4805                     // of the site type. Example:
4806                     //
4807                     // class Tree<A> { class Visitor { ... } }
4808                     // class PointTree extends Tree<Point> { ... }
4809                     // ...PointTree.Visitor...
4810                     //
4811                     // Then the type of the last expression above is
4812                     // Tree<Point>.Visitor.
4813                     else if (ownOuter.hasTag(CLASS) && site != ownOuter) {
4814                         Type normOuter = site;
4815                         if (normOuter.hasTag(CLASS)) {
4816                             normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
4817                         }
4818                         if (normOuter == null) // perhaps from an import
4819                             normOuter = types.erasure(ownOuter);
4820                         if (normOuter != ownOuter)
4821                             owntype = new ClassType(
4822                                 normOuter, List.nil(), owntype.tsym,
4823                                 owntype.getMetadata());
4824                     }
4825                 }
4826                 break;
4827             case VAR:
4828                 VarSymbol v = (VarSymbol)sym;
4829 
4830                 if (env.info.enclVar != null
4831                         && v.type.hasTag(NONE)) {
4832                     //self reference to implicitly typed variable declaration
4833                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
4834                     return tree.type = v.type = types.createErrorType(v.type);
4835                 }
4836 
4837                 // Test (4): if symbol is an instance field of a raw type,
4838                 // which is being assigned to, issue an unchecked warning if
4839                 // its type changes under erasure.
4840                 if (KindSelector.ASG.subset(pkind()) &&
4841                     v.owner.kind == TYP &&
4842                     (v.flags() & STATIC) == 0 &&
4843                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
4844                     Type s = types.asOuterSuper(site, v.owner);
4845                     if (s != null &&
4846                         s.isRaw() &&
4847                         !types.isSameType(v.type, v.erasure(types))) {
4848                         chk.warnUnchecked(tree.pos(), LintWarnings.UncheckedAssignToVar(v, s));
4849                     }
4850                 }
4851                 // The computed type of a variable is the type of the
4852                 // variable symbol, taken as a member of the site type.
4853                 owntype = (sym.owner.kind == TYP &&
4854                            sym.name != names._this && sym.name != names._super)
4855                     ? types.memberType(site, sym)
4856                     : sym.type;
4857 
4858                 // If the variable is a constant, record constant value in
4859                 // computed type.
4860                 if (v.getConstValue() != null && isStaticReference(tree))
4861                     owntype = owntype.constType(v.getConstValue());
4862 
4863                 if (resultInfo.pkind == KindSelector.VAL) {
4864                     owntype = capture(owntype); // capture "names as expressions"
4865                 }
4866                 break;
4867             case MTH: {
4868                 owntype = checkMethod(site, sym,
4869                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
4870                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
4871                         resultInfo.pt.getTypeArguments());
4872                 chk.checkRestricted(tree.pos(), sym);
4873                 break;
4874             }
4875             case PCK: case ERR:
4876                 owntype = sym.type;
4877                 break;
4878             default:
4879                 throw new AssertionError("unexpected kind: " + sym.kind +
4880                                          " in tree " + tree);
4881             }
4882 
4883             // Emit a `deprecation' warning if symbol is deprecated.
4884             // (for constructors (but not for constructor references), the error
4885             // was given when the constructor was resolved)
4886 
4887             if (sym.name != names.init || tree.hasTag(REFERENCE)) {
4888                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
4889                 chk.checkSunAPI(tree.pos(), sym);
4890                 chk.checkProfile(tree.pos(), sym);
4891                 chk.checkPreview(tree.pos(), env.info.scope.owner, site, sym);
4892             }
4893 
4894             if (pt.isErroneous()) {
4895                 owntype = types.createErrorType(owntype);
4896             }
4897 
4898             // If symbol is a variable, check that its type and
4899             // kind are compatible with the prototype and protokind.
4900             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
4901         }
4902 
4903         /** Check that variable is initialized and evaluate the variable's
4904          *  initializer, if not yet done. Also check that variable is not
4905          *  referenced before it is defined.
4906          *  @param tree    The tree making up the variable reference.
4907          *  @param env     The current environment.
4908          *  @param v       The variable's symbol.
4909          */
4910         private void checkInit(JCTree tree,
4911                                Env<AttrContext> env,
4912                                VarSymbol v,
4913                                boolean onlyWarning) {
4914             // A forward reference is diagnosed if the declaration position
4915             // of the variable is greater than the current tree position
4916             // and the tree and variable definition occur in the same class
4917             // definition.  Note that writes don't count as references.
4918             // This check applies only to class and instance
4919             // variables.  Local variables follow different scope rules,
4920             // and are subject to definite assignment checking.
4921             Env<AttrContext> initEnv = enclosingInitEnv(env);
4922             if (initEnv != null &&
4923                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
4924                 v.owner.kind == TYP &&
4925                 v.owner == env.info.scope.owner.enclClass() &&
4926                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
4927                 (!env.tree.hasTag(ASSIGN) ||
4928                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
4929                 if (!onlyWarning || isStaticEnumField(v)) {
4930                     Error errkey = (initEnv.info.enclVar == v) ?
4931                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
4932                     log.error(tree.pos(), errkey);
4933                 } else if (useBeforeDeclarationWarning) {
4934                     Warning warnkey = (initEnv.info.enclVar == v) ?
4935                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
4936                     log.warning(tree.pos(), warnkey);
4937                 }
4938             }
4939 
4940             v.getConstValue(); // ensure initializer is evaluated
4941 
4942             checkEnumInitializer(tree, env, v);
4943         }
4944 
4945         /**
4946          * Returns the enclosing init environment associated with this env (if any). An init env
4947          * can be either a field declaration env or a static/instance initializer env.
4948          */
4949         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
4950             while (true) {
4951                 switch (env.tree.getTag()) {
4952                     case VARDEF:
4953                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
4954                         if (vdecl.sym.owner.kind == TYP) {
4955                             //field
4956                             return env;
4957                         }
4958                         break;
4959                     case BLOCK:
4960                         if (env.next.tree.hasTag(CLASSDEF)) {
4961                             //instance/static initializer
4962                             return env;
4963                         }
4964                         break;
4965                     case METHODDEF:
4966                     case CLASSDEF:
4967                     case TOPLEVEL:
4968                         return null;
4969                 }
4970                 Assert.checkNonNull(env.next);
4971                 env = env.next;
4972             }
4973         }
4974 
4975         /**
4976          * Check for illegal references to static members of enum.  In
4977          * an enum type, constructors and initializers may not
4978          * reference its static members unless they are constant.
4979          *
4980          * @param tree    The tree making up the variable reference.
4981          * @param env     The current environment.
4982          * @param v       The variable's symbol.
4983          * @jls 8.9 Enum Types
4984          */
4985         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
4986             // JLS:
4987             //
4988             // "It is a compile-time error to reference a static field
4989             // of an enum type that is not a compile-time constant
4990             // (15.28) from constructors, instance initializer blocks,
4991             // or instance variable initializer expressions of that
4992             // type. It is a compile-time error for the constructors,
4993             // instance initializer blocks, or instance variable
4994             // initializer expressions of an enum constant e to refer
4995             // to itself or to an enum constant of the same type that
4996             // is declared to the right of e."
4997             if (isStaticEnumField(v)) {
4998                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
4999 
5000                 if (enclClass == null || enclClass.owner == null)
5001                     return;
5002 
5003                 // See if the enclosing class is the enum (or a
5004                 // subclass thereof) declaring v.  If not, this
5005                 // reference is OK.
5006                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
5007                     return;
5008 
5009                 // If the reference isn't from an initializer, then
5010                 // the reference is OK.
5011                 if (!Resolve.isInitializer(env))
5012                     return;
5013 
5014                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
5015             }
5016         }
5017 
5018         /** Is the given symbol a static, non-constant field of an Enum?
5019          *  Note: enum literals should not be regarded as such
5020          */
5021         private boolean isStaticEnumField(VarSymbol v) {
5022             return Flags.isEnum(v.owner) &&
5023                    Flags.isStatic(v) &&
5024                    !Flags.isConstant(v) &&
5025                    v.name != names._class;
5026         }
5027 
5028     /**
5029      * Check that method arguments conform to its instantiation.
5030      **/
5031     public Type checkMethod(Type site,
5032                             final Symbol sym,
5033                             ResultInfo resultInfo,
5034                             Env<AttrContext> env,
5035                             final List<JCExpression> argtrees,
5036                             List<Type> argtypes,
5037                             List<Type> typeargtypes) {
5038         // Test (5): if symbol is an instance method of a raw type, issue
5039         // an unchecked warning if its argument types change under erasure.
5040         if ((sym.flags() & STATIC) == 0 &&
5041             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
5042             Type s = types.asOuterSuper(site, sym.owner);
5043             if (s != null && s.isRaw() &&
5044                 !types.isSameTypes(sym.type.getParameterTypes(),
5045                                    sym.erasure(types).getParameterTypes())) {
5046                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedCallMbrOfRawType(sym, s));
5047             }
5048         }
5049 
5050         if (env.info.defaultSuperCallSite != null) {
5051             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
5052                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
5053                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
5054                 List<MethodSymbol> icand_sup =
5055                         types.interfaceCandidates(sup, (MethodSymbol)sym);
5056                 if (icand_sup.nonEmpty() &&
5057                         icand_sup.head != sym &&
5058                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
5059                     log.error(env.tree.pos(),
5060                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
5061                     break;
5062                 }
5063             }
5064             env.info.defaultSuperCallSite = null;
5065         }
5066 
5067         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
5068             JCMethodInvocation app = (JCMethodInvocation)env.tree;
5069             if (app.meth.hasTag(SELECT) &&
5070                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
5071                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
5072             }
5073         }
5074 
5075         // Compute the identifier's instantiated type.
5076         // For methods, we need to compute the instance type by
5077         // Resolve.instantiate from the symbol's type as well as
5078         // any type arguments and value arguments.
5079         Warner noteWarner = new Warner();
5080         try {
5081             Type owntype = rs.checkMethod(
5082                     env,
5083                     site,
5084                     sym,
5085                     resultInfo,
5086                     argtypes,
5087                     typeargtypes,
5088                     noteWarner);
5089 
5090             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
5091                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
5092 
5093             argtypes = argtypes.map(checkDeferredMap);
5094 
5095             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
5096                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedMethInvocationApplied(kindName(sym),
5097                         sym.name,
5098                         rs.methodArguments(sym.type.getParameterTypes()),
5099                         rs.methodArguments(argtypes.map(checkDeferredMap)),
5100                         kindName(sym.location()),
5101                         sym.location()));
5102                 if (resultInfo.pt != Infer.anyPoly ||
5103                         !owntype.hasTag(METHOD) ||
5104                         !owntype.isPartial()) {
5105                     //if this is not a partially inferred method type, erase return type. Otherwise,
5106                     //erasure is carried out in PartiallyInferredMethodType.check().
5107                     owntype = new MethodType(owntype.getParameterTypes(),
5108                             types.erasure(owntype.getReturnType()),
5109                             types.erasure(owntype.getThrownTypes()),
5110                             syms.methodClass);
5111                 }
5112             }
5113 
5114             PolyKind pkind = (sym.type.hasTag(FORALL) &&
5115                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
5116                  PolyKind.POLY : PolyKind.STANDALONE;
5117             TreeInfo.setPolyKind(env.tree, pkind);
5118 
5119             return (resultInfo.pt == Infer.anyPoly) ?
5120                     owntype :
5121                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
5122                             resultInfo.checkContext.inferenceContext());
5123         } catch (Infer.InferenceException ex) {
5124             //invalid target type - propagate exception outwards or report error
5125             //depending on the current check context
5126             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
5127             return types.createErrorType(site);
5128         } catch (Resolve.InapplicableMethodException ex) {
5129             final JCDiagnostic diag = ex.getDiagnostic();
5130             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
5131                 @Override
5132                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
5133                     return new Pair<>(sym, diag);
5134                 }
5135             };
5136             List<Type> argtypes2 = argtypes.map(
5137                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
5138             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
5139                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
5140             log.report(errDiag);
5141             return types.createErrorType(site);
5142         }
5143     }
5144 
5145     public void visitLiteral(JCLiteral tree) {
5146         result = check(tree, litType(tree.typetag).constType(tree.value),
5147                 KindSelector.VAL, resultInfo);
5148     }
5149     //where
5150     /** Return the type of a literal with given type tag.
5151      */
5152     Type litType(TypeTag tag) {
5153         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
5154     }
5155 
5156     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5157         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5158     }
5159 
5160     public void visitTypeArray(JCArrayTypeTree tree) {
5161         Type etype = attribType(tree.elemtype, env);
5162         Type type = new ArrayType(etype, syms.arrayClass);
5163         result = check(tree, type, KindSelector.TYP, resultInfo);
5164     }
5165 
5166     /** Visitor method for parameterized types.
5167      *  Bound checking is left until later, since types are attributed
5168      *  before supertype structure is completely known
5169      */
5170     public void visitTypeApply(JCTypeApply tree) {
5171         Type owntype = types.createErrorType(tree.type);
5172 
5173         // Attribute functor part of application and make sure it's a class.
5174         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5175 
5176         // Attribute type parameters
5177         List<Type> actuals = attribTypes(tree.arguments, env);
5178 
5179         if (clazztype.hasTag(CLASS)) {
5180             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5181             if (actuals.isEmpty()) //diamond
5182                 actuals = formals;
5183 
5184             if (actuals.length() == formals.length()) {
5185                 List<Type> a = actuals;
5186                 List<Type> f = formals;
5187                 while (a.nonEmpty()) {
5188                     a.head = a.head.withTypeVar(f.head);
5189                     a = a.tail;
5190                     f = f.tail;
5191                 }
5192                 // Compute the proper generic outer
5193                 Type clazzOuter = clazztype.getEnclosingType();
5194                 if (clazzOuter.hasTag(CLASS)) {
5195                     Type site;
5196                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5197                     if (clazz.hasTag(IDENT)) {
5198                         site = env.enclClass.sym.type;
5199                     } else if (clazz.hasTag(SELECT)) {
5200                         site = ((JCFieldAccess) clazz).selected.type;
5201                     } else throw new AssertionError(""+tree);
5202                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5203                         if (site.hasTag(CLASS))
5204                             site = types.asOuterSuper(site, clazzOuter.tsym);
5205                         if (site == null)
5206                             site = types.erasure(clazzOuter);
5207                         clazzOuter = site;
5208                     }
5209                 }
5210                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5211                                         clazztype.getMetadata());
5212             } else {
5213                 if (formals.length() != 0) {
5214                     log.error(tree.pos(),
5215                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5216                 } else {
5217                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5218                 }
5219                 owntype = types.createErrorType(tree.type);
5220             }
5221         } else if (clazztype.hasTag(ERROR)) {
5222             ErrorType parameterizedErroneous =
5223                     new ErrorType(clazztype.getOriginalType(),
5224                                   clazztype.tsym,
5225                                   clazztype.getMetadata());
5226 
5227             parameterizedErroneous.typarams_field = actuals;
5228             owntype = parameterizedErroneous;
5229         }
5230         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5231     }
5232 
5233     public void visitTypeUnion(JCTypeUnion tree) {
5234         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5235         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5236         for (JCExpression typeTree : tree.alternatives) {
5237             Type ctype = attribType(typeTree, env);
5238             ctype = chk.checkType(typeTree.pos(),
5239                           chk.checkClassType(typeTree.pos(), ctype),
5240                           syms.throwableType);
5241             if (!ctype.isErroneous()) {
5242                 //check that alternatives of a union type are pairwise
5243                 //unrelated w.r.t. subtyping
5244                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5245                     for (Type t : multicatchTypes) {
5246                         boolean sub = types.isSubtype(ctype, t);
5247                         boolean sup = types.isSubtype(t, ctype);
5248                         if (sub || sup) {
5249                             //assume 'a' <: 'b'
5250                             Type a = sub ? ctype : t;
5251                             Type b = sub ? t : ctype;
5252                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5253                         }
5254                     }
5255                 }
5256                 multicatchTypes.append(ctype);
5257                 if (all_multicatchTypes != null)
5258                     all_multicatchTypes.append(ctype);
5259             } else {
5260                 if (all_multicatchTypes == null) {
5261                     all_multicatchTypes = new ListBuffer<>();
5262                     all_multicatchTypes.appendList(multicatchTypes);
5263                 }
5264                 all_multicatchTypes.append(ctype);
5265             }
5266         }
5267         Type t = check(tree, types.lub(multicatchTypes.toList()),
5268                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5269         if (t.hasTag(CLASS)) {
5270             List<Type> alternatives =
5271                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5272             t = new UnionClassType((ClassType) t, alternatives);
5273         }
5274         tree.type = result = t;
5275     }
5276 
5277     public void visitTypeIntersection(JCTypeIntersection tree) {
5278         attribTypes(tree.bounds, env);
5279         tree.type = result = checkIntersection(tree, tree.bounds);
5280     }
5281 
5282     public void visitTypeParameter(JCTypeParameter tree) {
5283         TypeVar typeVar = (TypeVar) tree.type;
5284 
5285         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5286             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5287         }
5288 
5289         if (!typeVar.getUpperBound().isErroneous()) {
5290             //fixup type-parameter bound computed in 'attribTypeVariables'
5291             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5292         }
5293     }
5294 
5295     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5296         Set<Symbol> boundSet = new HashSet<>();
5297         if (bounds.nonEmpty()) {
5298             // accept class or interface or typevar as first bound.
5299             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5300             boundSet.add(types.erasure(bounds.head.type).tsym);
5301             if (bounds.head.type.isErroneous()) {
5302                 return bounds.head.type;
5303             }
5304             else if (bounds.head.type.hasTag(TYPEVAR)) {
5305                 // if first bound was a typevar, do not accept further bounds.
5306                 if (bounds.tail.nonEmpty()) {
5307                     log.error(bounds.tail.head.pos(),
5308                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5309                     return bounds.head.type;
5310                 }
5311             } else {
5312                 // if first bound was a class or interface, accept only interfaces
5313                 // as further bounds.
5314                 for (JCExpression bound : bounds.tail) {
5315                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5316                     if (bound.type.isErroneous()) {
5317                         bounds = List.of(bound);
5318                     }
5319                     else if (bound.type.hasTag(CLASS)) {
5320                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5321                     }
5322                 }
5323             }
5324         }
5325 
5326         if (bounds.length() == 0) {
5327             return syms.objectType;
5328         } else if (bounds.length() == 1) {
5329             return bounds.head.type;
5330         } else {
5331             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5332             // ... the variable's bound is a class type flagged COMPOUND
5333             // (see comment for TypeVar.bound).
5334             // In this case, generate a class tree that represents the
5335             // bound class, ...
5336             JCExpression extending;
5337             List<JCExpression> implementing;
5338             if (!bounds.head.type.isInterface()) {
5339                 extending = bounds.head;
5340                 implementing = bounds.tail;
5341             } else {
5342                 extending = null;
5343                 implementing = bounds;
5344             }
5345             JCClassDecl cd = make.at(tree).ClassDef(
5346                 make.Modifiers(PUBLIC | ABSTRACT),
5347                 names.empty, List.nil(),
5348                 extending, implementing, List.nil());
5349 
5350             ClassSymbol c = (ClassSymbol)owntype.tsym;
5351             Assert.check((c.flags() & COMPOUND) != 0);
5352             cd.sym = c;
5353             c.sourcefile = env.toplevel.sourcefile;
5354 
5355             // ... and attribute the bound class
5356             c.flags_field |= UNATTRIBUTED;
5357             Env<AttrContext> cenv = enter.classEnv(cd, env);
5358             typeEnvs.put(c, cenv);
5359             attribClass(c);
5360             return owntype;
5361         }
5362     }
5363 
5364     public void visitWildcard(JCWildcard tree) {
5365         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5366         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5367             ? syms.objectType
5368             : attribType(tree.inner, env);
5369         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
5370                                               tree.kind.kind,
5371                                               syms.boundClass),
5372                 KindSelector.TYP, resultInfo);
5373     }
5374 
5375     public void visitAnnotation(JCAnnotation tree) {
5376         Assert.error("should be handled in annotate");
5377     }
5378 
5379     @Override
5380     public void visitModifiers(JCModifiers tree) {
5381         //error recovery only:
5382         Assert.check(resultInfo.pkind == KindSelector.ERR);
5383 
5384         attribAnnotationTypes(tree.annotations, env);
5385     }
5386 
5387     public void visitAnnotatedType(JCAnnotatedType tree) {
5388         attribAnnotationTypes(tree.annotations, env);
5389         Type underlyingType = attribType(tree.underlyingType, env);
5390         Type annotatedType = underlyingType.preannotatedType();
5391 
5392         if (!env.info.isAnonymousNewClass)
5393             annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5394         result = tree.type = annotatedType;
5395     }
5396 
5397     public void visitErroneous(JCErroneous tree) {
5398         if (tree.errs != null) {
5399             WriteableScope newScope = env.info.scope;
5400 
5401             if (env.tree instanceof JCClassDecl) {
5402                 Symbol fakeOwner =
5403                     new MethodSymbol(BLOCK, names.empty, null,
5404                         env.info.scope.owner);
5405                 newScope = newScope.dupUnshared(fakeOwner);
5406             }
5407 
5408             Env<AttrContext> errEnv =
5409                     env.dup(env.tree,
5410                             env.info.dup(newScope));
5411             errEnv.info.returnResult = unknownExprInfo;
5412             for (JCTree err : tree.errs)
5413                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5414         }
5415         result = tree.type = syms.errType;
5416     }
5417 
5418     /** Default visitor method for all other trees.
5419      */
5420     public void visitTree(JCTree tree) {
5421         throw new AssertionError();
5422     }
5423 
5424     /**
5425      * Attribute an env for either a top level tree or class or module declaration.
5426      */
5427     public void attrib(Env<AttrContext> env) {
5428         switch (env.tree.getTag()) {
5429             case MODULEDEF:
5430                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5431                 break;
5432             case PACKAGEDEF:
5433                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5434                 break;
5435             default:
5436                 attribClass(env.tree.pos(), env.enclClass.sym);
5437         }
5438 
5439         annotate.flush();
5440     }
5441 
5442     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5443         try {
5444             annotate.flush();
5445             attribPackage(p);
5446         } catch (CompletionFailure ex) {
5447             chk.completionError(pos, ex);
5448         }
5449     }
5450 
5451     void attribPackage(PackageSymbol p) {
5452         attribWithLint(p,
5453                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5454     }
5455 
5456     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5457         try {
5458             annotate.flush();
5459             attribModule(m);
5460         } catch (CompletionFailure ex) {
5461             chk.completionError(pos, ex);
5462         }
5463     }
5464 
5465     void attribModule(ModuleSymbol m) {
5466         attribWithLint(m, env -> attribStat(env.tree, env));
5467     }
5468 
5469     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5470         Env<AttrContext> env = typeEnvs.get(sym);
5471 
5472         Env<AttrContext> lintEnv = env;
5473         while (lintEnv.info.lint == null)
5474             lintEnv = lintEnv.next;
5475 
5476         Lint lint = lintEnv.info.lint.augment(sym);
5477 
5478         Lint prevLint = chk.setLint(lint);
5479         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5480 
5481         try {
5482             deferredLintHandler.flush(env.tree, lint);
5483             attrib.accept(env);
5484         } finally {
5485             log.useSource(prev);
5486             chk.setLint(prevLint);
5487         }
5488     }
5489 
5490     /** Main method: attribute class definition associated with given class symbol.
5491      *  reporting completion failures at the given position.
5492      *  @param pos The source position at which completion errors are to be
5493      *             reported.
5494      *  @param c   The class symbol whose definition will be attributed.
5495      */
5496     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5497         try {
5498             annotate.flush();
5499             attribClass(c);
5500         } catch (CompletionFailure ex) {
5501             chk.completionError(pos, ex);
5502         }
5503     }
5504 
5505     /** Attribute class definition associated with given class symbol.
5506      *  @param c   The class symbol whose definition will be attributed.
5507      */
5508     void attribClass(ClassSymbol c) throws CompletionFailure {
5509         if (c.type.hasTag(ERROR)) return;
5510 
5511         // Check for cycles in the inheritance graph, which can arise from
5512         // ill-formed class files.
5513         chk.checkNonCyclic(null, c.type);
5514 
5515         Type st = types.supertype(c.type);
5516         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5517             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0) {
5518             // First, attribute superclass.
5519             if (st.hasTag(CLASS))
5520                 attribClass((ClassSymbol)st.tsym);
5521 
5522             // Next attribute owner, if it is a class.
5523             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5524                 attribClass((ClassSymbol)c.owner);
5525 
5526             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5527         }
5528 
5529         // The previous operations might have attributed the current class
5530         // if there was a cycle. So we test first whether the class is still
5531         // UNATTRIBUTED.
5532         if ((c.flags_field & UNATTRIBUTED) != 0) {
5533             c.flags_field &= ~UNATTRIBUTED;
5534 
5535             // Get environment current at the point of class definition.
5536             Env<AttrContext> env = typeEnvs.get(c);
5537 
5538             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5539             // because the annotations were not available at the time the env was created. Therefore,
5540             // we look up the environment chain for the first enclosing environment for which the
5541             // lint value is set. Typically, this is the parent env, but might be further if there
5542             // are any envs created as a result of TypeParameter nodes.
5543             Env<AttrContext> lintEnv = env;
5544             while (lintEnv.info.lint == null)
5545                 lintEnv = lintEnv.next;
5546 
5547             // Having found the enclosing lint value, we can initialize the lint value for this class
5548             env.info.lint = lintEnv.info.lint.augment(c);
5549 
5550             Lint prevLint = chk.setLint(env.info.lint);
5551             JavaFileObject prev = log.useSource(c.sourcefile);
5552             ResultInfo prevReturnRes = env.info.returnResult;
5553 
5554             try {
5555                 if (c.isSealed() &&
5556                         !c.isEnum() &&
5557                         !c.isPermittedExplicit &&
5558                         c.getPermittedSubclasses().isEmpty()) {
5559                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5560                 }
5561 
5562                 if (c.isSealed()) {
5563                     Set<Symbol> permittedTypes = new HashSet<>();
5564                     boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5565                     for (Type subType : c.getPermittedSubclasses()) {
5566                         if (subType.isErroneous()) {
5567                             // the type already caused errors, don't produce more potentially misleading errors
5568                             continue;
5569                         }
5570                         boolean isTypeVar = false;
5571                         if (subType.getTag() == TYPEVAR) {
5572                             isTypeVar = true; //error recovery
5573                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5574                                     Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subType)));
5575                         }
5576                         if (subType.tsym.isAnonymous() && !c.isEnum()) {
5577                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5578                         }
5579                         if (permittedTypes.contains(subType.tsym)) {
5580                             DiagnosticPosition pos =
5581                                     env.enclClass.permitting.stream()
5582                                             .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subType.tsym, permittedExpr, true) != null)
5583                                             .limit(2).collect(List.collector()).get(1);
5584                             log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subType)));
5585                         } else {
5586                             permittedTypes.add(subType.tsym);
5587                         }
5588                         if (sealedInUnnamed) {
5589                             if (subType.tsym.packge() != c.packge()) {
5590                                 log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5591                                         Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5592                                 );
5593                             }
5594                         } else if (subType.tsym.packge().modle != c.packge().modle) {
5595                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5596                                     Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5597                             );
5598                         }
5599                         if (subType.tsym == c.type.tsym || types.isSuperType(subType, c.type)) {
5600                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, ((JCClassDecl)env.tree).permitting),
5601                                     Errors.InvalidPermitsClause(
5602                                             subType.tsym == c.type.tsym ?
5603                                                     Fragments.MustNotBeSameClass :
5604                                                     Fragments.MustNotBeSupertype(subType)
5605                                     )
5606                             );
5607                         } else if (!isTypeVar) {
5608                             boolean thisIsASuper = types.directSupertypes(subType)
5609                                                         .stream()
5610                                                         .anyMatch(d -> d.tsym == c);
5611                             if (!thisIsASuper) {
5612                                 if(c.isInterface()) {
5613                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5614                                             Errors.InvalidPermitsClause(Fragments.DoesntImplementSealed(kindName(subType.tsym), subType)));
5615                                 } else {
5616                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5617                                             Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subType)));
5618                                 }
5619                             }
5620                         }
5621                     }
5622                 }
5623 
5624                 List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5625                                                       .stream()
5626                                                       .filter(s -> s.tsym.isSealed())
5627                                                       .map(s -> (ClassSymbol) s.tsym)
5628                                                       .collect(List.collector());
5629 
5630                 if (sealedSupers.isEmpty()) {
5631                     if ((c.flags_field & Flags.NON_SEALED) != 0) {
5632                         boolean hasErrorSuper = false;
5633 
5634                         hasErrorSuper |= types.directSupertypes(c.type)
5635                                               .stream()
5636                                               .anyMatch(s -> s.tsym.kind == Kind.ERR);
5637 
5638                         ClassType ct = (ClassType) c.type;
5639 
5640                         hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5641 
5642                         if (!hasErrorSuper) {
5643                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5644                         }
5645                     }
5646                 } else {
5647                     if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5648                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5649                     }
5650 
5651                     if (!c.type.isCompound()) {
5652                         for (ClassSymbol supertypeSym : sealedSupers) {
5653                             if (!supertypeSym.isPermittedSubclass(c.type.tsym)) {
5654                                 log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5655                             }
5656                         }
5657                         if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5658                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5659                                     c.isInterface() ?
5660                                             Errors.NonSealedOrSealedExpected :
5661                                             Errors.NonSealedSealedOrFinalExpected);
5662                         }
5663                     }
5664                 }
5665 
5666                 deferredLintHandler.flush(env.tree, env.info.lint);
5667                 env.info.returnResult = null;
5668                 // java.lang.Enum may not be subclassed by a non-enum
5669                 if (st.tsym == syms.enumSym &&
5670                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5671                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5672 
5673                 // Enums may not be extended by source-level classes
5674                 if (st.tsym != null &&
5675                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5676                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5677                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5678                 }
5679 
5680                 if (rs.isSerializable(c.type)) {
5681                     env.info.isSerializable = true;
5682                 }
5683 
5684                 attribClassBody(env, c);
5685 
5686                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5687                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5688                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5689                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5690 
5691                 if (c.isImplicit()) {
5692                     chk.checkHasMain(env.tree.pos(), c);
5693                 }
5694             } finally {
5695                 env.info.returnResult = prevReturnRes;
5696                 log.useSource(prev);
5697                 chk.setLint(prevLint);
5698             }
5699 
5700         }
5701     }
5702 
5703     public void visitImport(JCImport tree) {
5704         // nothing to do
5705     }
5706 
5707     public void visitModuleDef(JCModuleDecl tree) {
5708         tree.sym.completeUsesProvides();
5709         ModuleSymbol msym = tree.sym;
5710         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5711         Lint prevLint = chk.setLint(lint);
5712         chk.checkModuleName(tree);
5713         chk.checkDeprecatedAnnotation(tree, msym);
5714 
5715         try {
5716             deferredLintHandler.flush(tree, lint);
5717         } finally {
5718             chk.setLint(prevLint);
5719         }
5720     }
5721 
5722     /** Finish the attribution of a class. */
5723     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5724         JCClassDecl tree = (JCClassDecl)env.tree;
5725         Assert.check(c == tree.sym);
5726 
5727         // Validate type parameters, supertype and interfaces.
5728         attribStats(tree.typarams, env);
5729         if (!c.isAnonymous()) {
5730             //already checked if anonymous
5731             chk.validate(tree.typarams, env);
5732             chk.validate(tree.extending, env);
5733             chk.validate(tree.implementing, env);
5734         }
5735 
5736         chk.checkRequiresIdentity(tree, env.info.lint);
5737 
5738         c.markAbstractIfNeeded(types);
5739 
5740         // If this is a non-abstract class, check that it has no abstract
5741         // methods or unimplemented methods of an implemented interface.
5742         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
5743             chk.checkAllDefined(tree.pos(), c);
5744         }
5745 
5746         if ((c.flags() & ANNOTATION) != 0) {
5747             if (tree.implementing.nonEmpty())
5748                 log.error(tree.implementing.head.pos(),
5749                           Errors.CantExtendIntfAnnotation);
5750             if (tree.typarams.nonEmpty()) {
5751                 log.error(tree.typarams.head.pos(),
5752                           Errors.IntfAnnotationCantHaveTypeParams(c));
5753             }
5754 
5755             // If this annotation type has a @Repeatable, validate
5756             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
5757             // If this annotation type has a @Repeatable, validate
5758             if (repeatable != null) {
5759                 // get diagnostic position for error reporting
5760                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
5761                 Assert.checkNonNull(cbPos);
5762 
5763                 chk.validateRepeatable(c, repeatable, cbPos);
5764             }
5765         } else {
5766             // Check that all extended classes and interfaces
5767             // are compatible (i.e. no two define methods with same arguments
5768             // yet different return types).  (JLS 8.4.8.3)
5769             chk.checkCompatibleSupertypes(tree.pos(), c.type);
5770             chk.checkDefaultMethodClashes(tree.pos(), c.type);
5771             chk.checkPotentiallyAmbiguousOverloads(tree, c.type);
5772         }
5773 
5774         // Check that class does not import the same parameterized interface
5775         // with two different argument lists.
5776         chk.checkClassBounds(tree.pos(), c.type);
5777 
5778         tree.type = c.type;
5779 
5780         for (List<JCTypeParameter> l = tree.typarams;
5781              l.nonEmpty(); l = l.tail) {
5782              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
5783         }
5784 
5785         // Check that a generic class doesn't extend Throwable
5786         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
5787             log.error(tree.extending.pos(), Errors.GenericThrowable);
5788 
5789         // Check that all methods which implement some
5790         // method conform to the method they implement.
5791         chk.checkImplementations(tree);
5792 
5793         //check that a resource implementing AutoCloseable cannot throw InterruptedException
5794         checkAutoCloseable(tree.pos(), env, c.type);
5795 
5796         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
5797             // Attribute declaration
5798             attribStat(l.head, env);
5799             // Check that declarations in inner classes are not static (JLS 8.1.2)
5800             // Make an exception for static constants.
5801             if (!allowRecords &&
5802                     c.owner.kind != PCK &&
5803                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
5804                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
5805                 VarSymbol sym = null;
5806                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
5807                 if (sym == null ||
5808                         sym.kind != VAR ||
5809                         sym.getConstValue() == null)
5810                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
5811             }
5812         }
5813 
5814         // Check for proper placement of super()/this() calls.
5815         chk.checkSuperInitCalls(tree);
5816 
5817         // Check for cycles among non-initial constructors.
5818         chk.checkCyclicConstructors(tree);
5819 
5820         // Check for cycles among annotation elements.
5821         chk.checkNonCyclicElements(tree);
5822 
5823         // Check for proper use of serialVersionUID and other
5824         // serialization-related fields and methods
5825         if (env.info.lint.isEnabled(LintCategory.SERIAL)
5826                 && rs.isSerializable(c.type)
5827                 && !c.isAnonymous()) {
5828             chk.checkSerialStructure(tree, c);
5829         }
5830         // Correctly organize the positions of the type annotations
5831         typeAnnotations.organizeTypeAnnotationsBodies(tree);
5832 
5833         // Check type annotations applicability rules
5834         validateTypeAnnotations(tree, false);
5835     }
5836         // where
5837         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
5838         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
5839             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
5840                 if (types.isSameType(al.head.annotationType.type, t))
5841                     return al.head.pos();
5842             }
5843 
5844             return null;
5845         }
5846 
5847     private Type capture(Type type) {
5848         return types.capture(type);
5849     }
5850 
5851     private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
5852         if (type.isErroneous()) {
5853             tree.vartype = make.at(tree.pos()).Erroneous();
5854         } else {
5855             tree.vartype = make.at(tree.pos()).Type(type);
5856         }
5857     }
5858 
5859     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
5860         tree.accept(new TypeAnnotationsValidator(sigOnly));
5861     }
5862     //where
5863     private final class TypeAnnotationsValidator extends TreeScanner {
5864 
5865         private final boolean sigOnly;
5866         public TypeAnnotationsValidator(boolean sigOnly) {
5867             this.sigOnly = sigOnly;
5868         }
5869 
5870         public void visitAnnotation(JCAnnotation tree) {
5871             chk.validateTypeAnnotation(tree, null, false);
5872             super.visitAnnotation(tree);
5873         }
5874         public void visitAnnotatedType(JCAnnotatedType tree) {
5875             if (!tree.underlyingType.type.isErroneous()) {
5876                 super.visitAnnotatedType(tree);
5877             }
5878         }
5879         public void visitTypeParameter(JCTypeParameter tree) {
5880             chk.validateTypeAnnotations(tree.annotations, tree.type.tsym, true);
5881             scan(tree.bounds);
5882             // Don't call super.
5883             // This is needed because above we call validateTypeAnnotation with
5884             // false, which would forbid annotations on type parameters.
5885             // super.visitTypeParameter(tree);
5886         }
5887         public void visitMethodDef(JCMethodDecl tree) {
5888             if (tree.recvparam != null &&
5889                     !tree.recvparam.vartype.type.isErroneous()) {
5890                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
5891             }
5892             if (tree.restype != null && tree.restype.type != null) {
5893                 validateAnnotatedType(tree.restype, tree.restype.type);
5894             }
5895             if (sigOnly) {
5896                 scan(tree.mods);
5897                 scan(tree.restype);
5898                 scan(tree.typarams);
5899                 scan(tree.recvparam);
5900                 scan(tree.params);
5901                 scan(tree.thrown);
5902             } else {
5903                 scan(tree.defaultValue);
5904                 scan(tree.body);
5905             }
5906         }
5907         public void visitVarDef(final JCVariableDecl tree) {
5908             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
5909             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
5910                 validateAnnotatedType(tree.vartype, tree.sym.type);
5911             scan(tree.mods);
5912             scan(tree.vartype);
5913             if (!sigOnly) {
5914                 scan(tree.init);
5915             }
5916         }
5917         public void visitTypeCast(JCTypeCast tree) {
5918             if (tree.clazz != null && tree.clazz.type != null)
5919                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5920             super.visitTypeCast(tree);
5921         }
5922         public void visitTypeTest(JCInstanceOf tree) {
5923             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
5924                 validateAnnotatedType(tree.pattern, tree.pattern.type);
5925             super.visitTypeTest(tree);
5926         }
5927         public void visitNewClass(JCNewClass tree) {
5928             if (tree.clazz != null && tree.clazz.type != null) {
5929                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
5930                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
5931                             tree.clazz.type.tsym);
5932                 }
5933                 if (tree.def != null) {
5934                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
5935                 }
5936 
5937                 validateAnnotatedType(tree.clazz, tree.clazz.type);
5938             }
5939             super.visitNewClass(tree);
5940         }
5941         public void visitNewArray(JCNewArray tree) {
5942             if (tree.elemtype != null && tree.elemtype.type != null) {
5943                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
5944                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
5945                             tree.elemtype.type.tsym);
5946                 }
5947                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
5948             }
5949             super.visitNewArray(tree);
5950         }
5951         public void visitClassDef(JCClassDecl tree) {
5952             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
5953             if (sigOnly) {
5954                 scan(tree.mods);
5955                 scan(tree.typarams);
5956                 scan(tree.extending);
5957                 scan(tree.implementing);
5958             }
5959             for (JCTree member : tree.defs) {
5960                 if (member.hasTag(Tag.CLASSDEF)) {
5961                     continue;
5962                 }
5963                 scan(member);
5964             }
5965         }
5966         public void visitBlock(JCBlock tree) {
5967             if (!sigOnly) {
5968                 scan(tree.stats);
5969             }
5970         }
5971 
5972         /* I would want to model this after
5973          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
5974          * and override visitSelect and visitTypeApply.
5975          * However, we only set the annotated type in the top-level type
5976          * of the symbol.
5977          * Therefore, we need to override each individual location where a type
5978          * can occur.
5979          */
5980         private void validateAnnotatedType(final JCTree errtree, final Type type) {
5981             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
5982 
5983             if (type.isPrimitiveOrVoid()) {
5984                 return;
5985             }
5986 
5987             JCTree enclTr = errtree;
5988             Type enclTy = type;
5989 
5990             boolean repeat = true;
5991             while (repeat) {
5992                 if (enclTr.hasTag(TYPEAPPLY)) {
5993                     List<Type> tyargs = enclTy.getTypeArguments();
5994                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
5995                     if (trargs.length() > 0) {
5996                         // Nothing to do for diamonds
5997                         if (tyargs.length() == trargs.length()) {
5998                             for (int i = 0; i < tyargs.length(); ++i) {
5999                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
6000                             }
6001                         }
6002                         // If the lengths don't match, it's either a diamond
6003                         // or some nested type that redundantly provides
6004                         // type arguments in the tree.
6005                     }
6006 
6007                     // Look at the clazz part of a generic type
6008                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
6009                 }
6010 
6011                 if (enclTr.hasTag(SELECT)) {
6012                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
6013                     if (enclTy != null &&
6014                             !enclTy.hasTag(NONE)) {
6015                         enclTy = enclTy.getEnclosingType();
6016                     }
6017                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
6018                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
6019                     if (enclTy == null || enclTy.hasTag(NONE)) {
6020                         ListBuffer<Attribute.TypeCompound> onlyTypeAnnotationsBuf = new ListBuffer<>();
6021                         for (JCAnnotation an : at.getAnnotations()) {
6022                             if (chk.isTypeAnnotation(an, false)) {
6023                                 onlyTypeAnnotationsBuf.add((Attribute.TypeCompound) an.attribute);
6024                             }
6025                         }
6026                         List<Attribute.TypeCompound> onlyTypeAnnotations = onlyTypeAnnotationsBuf.toList();
6027                         if (!onlyTypeAnnotations.isEmpty()) {
6028                             Fragment annotationFragment = onlyTypeAnnotations.size() == 1 ?
6029                                     Fragments.TypeAnnotation1(onlyTypeAnnotations.head) :
6030                                     Fragments.TypeAnnotation(onlyTypeAnnotations);
6031                             JCDiagnostic.AnnotatedType annotatedType = new JCDiagnostic.AnnotatedType(
6032                                     type.stripMetadata().annotatedType(onlyTypeAnnotations));
6033                             log.error(at.underlyingType.pos(), Errors.TypeAnnotationInadmissible(annotationFragment,
6034                                     type.tsym.owner, annotatedType));
6035                         }
6036                         repeat = false;
6037                     }
6038                     enclTr = at.underlyingType;
6039                     // enclTy doesn't need to be changed
6040                 } else if (enclTr.hasTag(IDENT)) {
6041                     repeat = false;
6042                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
6043                     JCWildcard wc = (JCWildcard) enclTr;
6044                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
6045                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
6046                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
6047                     } else {
6048                         // Nothing to do for UNBOUND
6049                     }
6050                     repeat = false;
6051                 } else if (enclTr.hasTag(TYPEARRAY)) {
6052                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
6053                     validateAnnotatedType(art.getType(), art.elemtype.type);
6054                     repeat = false;
6055                 } else if (enclTr.hasTag(TYPEUNION)) {
6056                     JCTypeUnion ut = (JCTypeUnion) enclTr;
6057                     for (JCTree t : ut.getTypeAlternatives()) {
6058                         validateAnnotatedType(t, t.type);
6059                     }
6060                     repeat = false;
6061                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
6062                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
6063                     for (JCTree t : it.getBounds()) {
6064                         validateAnnotatedType(t, t.type);
6065                     }
6066                     repeat = false;
6067                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
6068                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
6069                     repeat = false;
6070                 } else {
6071                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
6072                             " within: "+ errtree + " with kind: " + errtree.getKind());
6073                 }
6074             }
6075         }
6076 
6077         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
6078                 Symbol sym) {
6079             // Ensure that no declaration annotations are present.
6080             // Note that a tree type might be an AnnotatedType with
6081             // empty annotations, if only declaration annotations were given.
6082             // This method will raise an error for such a type.
6083             for (JCAnnotation ai : annotations) {
6084                 if (!ai.type.isErroneous() &&
6085                         typeAnnotations.annotationTargetType(ai, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
6086                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
6087                 }
6088             }
6089         }
6090     }
6091 
6092     // <editor-fold desc="post-attribution visitor">
6093 
6094     /**
6095      * Handle missing types/symbols in an AST. This routine is useful when
6096      * the compiler has encountered some errors (which might have ended up
6097      * terminating attribution abruptly); if the compiler is used in fail-over
6098      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
6099      * prevents NPE to be propagated during subsequent compilation steps.
6100      */
6101     public void postAttr(JCTree tree) {
6102         new PostAttrAnalyzer().scan(tree);
6103     }
6104 
6105     class PostAttrAnalyzer extends TreeScanner {
6106 
6107         private void initTypeIfNeeded(JCTree that) {
6108             if (that.type == null) {
6109                 if (that.hasTag(METHODDEF)) {
6110                     that.type = dummyMethodType((JCMethodDecl)that);
6111                 } else {
6112                     that.type = syms.unknownType;
6113                 }
6114             }
6115         }
6116 
6117         /* Construct a dummy method type. If we have a method declaration,
6118          * and the declared return type is void, then use that return type
6119          * instead of UNKNOWN to avoid spurious error messages in lambda
6120          * bodies (see:JDK-8041704).
6121          */
6122         private Type dummyMethodType(JCMethodDecl md) {
6123             Type restype = syms.unknownType;
6124             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
6125                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
6126                 if (prim.typetag == VOID)
6127                     restype = syms.voidType;
6128             }
6129             return new MethodType(List.nil(), restype,
6130                                   List.nil(), syms.methodClass);
6131         }
6132         private Type dummyMethodType() {
6133             return dummyMethodType(null);
6134         }
6135 
6136         @Override
6137         public void scan(JCTree tree) {
6138             if (tree == null) return;
6139             if (tree instanceof JCExpression) {
6140                 initTypeIfNeeded(tree);
6141             }
6142             super.scan(tree);
6143         }
6144 
6145         @Override
6146         public void visitIdent(JCIdent that) {
6147             if (that.sym == null) {
6148                 that.sym = syms.unknownSymbol;
6149             }
6150         }
6151 
6152         @Override
6153         public void visitSelect(JCFieldAccess that) {
6154             if (that.sym == null) {
6155                 that.sym = syms.unknownSymbol;
6156             }
6157             super.visitSelect(that);
6158         }
6159 
6160         @Override
6161         public void visitClassDef(JCClassDecl that) {
6162             initTypeIfNeeded(that);
6163             if (that.sym == null) {
6164                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
6165             }
6166             super.visitClassDef(that);
6167         }
6168 
6169         @Override
6170         public void visitMethodDef(JCMethodDecl that) {
6171             initTypeIfNeeded(that);
6172             if (that.sym == null) {
6173                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
6174             }
6175             super.visitMethodDef(that);
6176         }
6177 
6178         @Override
6179         public void visitVarDef(JCVariableDecl that) {
6180             initTypeIfNeeded(that);
6181             if (that.sym == null) {
6182                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
6183                 that.sym.adr = 0;
6184             }
6185             if (that.vartype == null) {
6186                 that.vartype = make.at(Position.NOPOS).Erroneous();
6187             }
6188             super.visitVarDef(that);
6189         }
6190 
6191         @Override
6192         public void visitBindingPattern(JCBindingPattern that) {
6193             initTypeIfNeeded(that);
6194             initTypeIfNeeded(that.var);
6195             if (that.var.sym == null) {
6196                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6197                 that.var.sym.adr = 0;
6198             }
6199             super.visitBindingPattern(that);
6200         }
6201 
6202         @Override
6203         public void visitRecordPattern(JCRecordPattern that) {
6204             initTypeIfNeeded(that);
6205             if (that.record == null) {
6206                 that.record = new ClassSymbol(0, TreeInfo.name(that.deconstructor),
6207                                               that.type, syms.noSymbol);
6208             }
6209             if (that.fullComponentTypes == null) {
6210                 that.fullComponentTypes = List.nil();
6211             }
6212             super.visitRecordPattern(that);
6213         }
6214 
6215         @Override
6216         public void visitNewClass(JCNewClass that) {
6217             if (that.constructor == null) {
6218                 that.constructor = new MethodSymbol(0, names.init,
6219                         dummyMethodType(), syms.noSymbol);
6220             }
6221             if (that.constructorType == null) {
6222                 that.constructorType = syms.unknownType;
6223             }
6224             super.visitNewClass(that);
6225         }
6226 
6227         @Override
6228         public void visitAssignop(JCAssignOp that) {
6229             if (that.operator == null) {
6230                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6231                         -1, syms.noSymbol);
6232             }
6233             super.visitAssignop(that);
6234         }
6235 
6236         @Override
6237         public void visitBinary(JCBinary that) {
6238             if (that.operator == null) {
6239                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6240                         -1, syms.noSymbol);
6241             }
6242             super.visitBinary(that);
6243         }
6244 
6245         @Override
6246         public void visitUnary(JCUnary that) {
6247             if (that.operator == null) {
6248                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6249                         -1, syms.noSymbol);
6250             }
6251             super.visitUnary(that);
6252         }
6253 
6254         @Override
6255         public void visitReference(JCMemberReference that) {
6256             super.visitReference(that);
6257             if (that.sym == null) {
6258                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6259                         syms.noSymbol);
6260             }
6261         }
6262     }
6263     // </editor-fold>
6264 
6265     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6266         new TreeScanner() {
6267             Symbol packge = pkg;
6268             @Override
6269             public void visitIdent(JCIdent that) {
6270                 that.sym = packge;
6271             }
6272 
6273             @Override
6274             public void visitSelect(JCFieldAccess that) {
6275                 that.sym = packge;
6276                 packge = packge.owner;
6277                 super.visitSelect(that);
6278             }
6279         }.scan(pid);
6280     }
6281 
6282 }