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