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