1 /*
   2  * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.tools.javac.comp;
  27 
  28 import java.util.*;
  29 import java.util.function.BiConsumer;
  30 import java.util.function.Consumer;
  31 import java.util.stream.Stream;
  32 
  33 import javax.lang.model.element.ElementKind;
  34 import javax.tools.JavaFileObject;
  35 
  36 import com.sun.source.tree.CaseTree;
  37 import com.sun.source.tree.IdentifierTree;
  38 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
  39 import com.sun.source.tree.MemberSelectTree;
  40 import com.sun.source.tree.TreeVisitor;
  41 import com.sun.source.util.SimpleTreeVisitor;
  42 import com.sun.tools.javac.code.*;
  43 import com.sun.tools.javac.code.Lint.LintCategory;
  44 import com.sun.tools.javac.code.LintMapper;
  45 import com.sun.tools.javac.code.Scope.WriteableScope;
  46 import com.sun.tools.javac.code.Source.Feature;
  47 import com.sun.tools.javac.code.Symbol.*;
  48 import com.sun.tools.javac.code.Type.*;
  49 import com.sun.tools.javac.code.Types.FunctionDescriptorLookupError;
  50 import com.sun.tools.javac.comp.ArgumentAttr.LocalCacheContext;
  51 import com.sun.tools.javac.comp.Check.CheckContext;
  52 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
  53 import com.sun.tools.javac.comp.MatchBindingsComputer.MatchBindings;
  54 import com.sun.tools.javac.jvm.*;
  55 
  56 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
  57 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
  58 import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
  59 
  60 import com.sun.tools.javac.resources.CompilerProperties.Errors;
  61 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
  62 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings;
  63 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
  64 import com.sun.tools.javac.tree.*;
  65 import com.sun.tools.javac.tree.JCTree.*;
  66 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
  67 import com.sun.tools.javac.util.*;
  68 import com.sun.tools.javac.util.DefinedBy.Api;
  69 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  70 import com.sun.tools.javac.util.JCDiagnostic.Error;
  71 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
  72 import com.sun.tools.javac.util.JCDiagnostic.Warning;
  73 import com.sun.tools.javac.util.List;
  74 
  75 import static com.sun.tools.javac.code.Flags.*;
  76 import static com.sun.tools.javac.code.Flags.ANNOTATION;
  77 import static com.sun.tools.javac.code.Flags.BLOCK;
  78 import static com.sun.tools.javac.code.Kinds.*;
  79 import static com.sun.tools.javac.code.Kinds.Kind.*;
  80 import static com.sun.tools.javac.code.TypeTag.*;
  81 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
  82 import static com.sun.tools.javac.tree.JCTree.Tag.*;
  83 
  84 /** This is the main context-dependent analysis phase in GJC. It
  85  *  encompasses name resolution, type checking and constant folding as
  86  *  subtasks. Some subtasks involve auxiliary classes.
  87  *  @see Check
  88  *  @see Resolve
  89  *  @see ConstFold
  90  *  @see Infer
  91  *
  92  *  <p><b>This is NOT part of any supported API.
  93  *  If you write code that depends on this, you do so at your own risk.
  94  *  This code and its internal interfaces are subject to change or
  95  *  deletion without notice.</b>
  96  */
  97 public class Attr extends JCTree.Visitor {
  98     protected static final Context.Key<Attr> attrKey = new Context.Key<>();
  99 
 100     final Names names;
 101     final Log log;
 102     final LintMapper lintMapper;
 103     final Symtab syms;
 104     final Resolve rs;
 105     final Operators operators;
 106     final Infer infer;
 107     final Analyzer analyzer;
 108     final DeferredAttr deferredAttr;
 109     final Check chk;
 110     final Flow flow;
 111     final MemberEnter memberEnter;
 112     final TypeEnter typeEnter;
 113     final TreeMaker make;
 114     final ConstFold cfolder;
 115     final Enter enter;
 116     final Target target;
 117     final Types types;
 118     final Preview preview;
 119     final JCDiagnostic.Factory diags;
 120     final TypeAnnotations typeAnnotations;
 121     final TypeEnvs typeEnvs;
 122     final Dependencies dependencies;
 123     final Annotate annotate;
 124     final ArgumentAttr argumentAttr;
 125     final MatchBindingsComputer matchBindingsComputer;
 126     final AttrRecover attrRecover;
 127     final LocalProxyVarsGen localProxyVarsGen;
 128 
 129     public static Attr instance(Context context) {
 130         Attr instance = context.get(attrKey);
 131         if (instance == null)
 132             instance = new Attr(context);
 133         return instance;
 134     }
 135 
 136     @SuppressWarnings("this-escape")
 137     protected Attr(Context context) {
 138         context.put(attrKey, this);
 139 
 140         names = Names.instance(context);
 141         log = Log.instance(context);
 142         lintMapper = LintMapper.instance(context);
 143         syms = Symtab.instance(context);
 144         rs = Resolve.instance(context);
 145         operators = Operators.instance(context);
 146         chk = Check.instance(context);
 147         flow = Flow.instance(context);
 148         memberEnter = MemberEnter.instance(context);
 149         typeEnter = TypeEnter.instance(context);
 150         make = TreeMaker.instance(context);
 151         enter = Enter.instance(context);
 152         infer = Infer.instance(context);
 153         analyzer = Analyzer.instance(context);
 154         deferredAttr = DeferredAttr.instance(context);
 155         cfolder = ConstFold.instance(context);
 156         target = Target.instance(context);
 157         types = Types.instance(context);
 158         preview = Preview.instance(context);
 159         diags = JCDiagnostic.Factory.instance(context);
 160         annotate = Annotate.instance(context);
 161         typeAnnotations = TypeAnnotations.instance(context);
 162         typeEnvs = TypeEnvs.instance(context);
 163         dependencies = Dependencies.instance(context);
 164         argumentAttr = ArgumentAttr.instance(context);
 165         matchBindingsComputer = MatchBindingsComputer.instance(context);
 166         attrRecover = AttrRecover.instance(context);
 167         localProxyVarsGen = LocalProxyVarsGen.instance(context);
 168 
 169         Options options = Options.instance(context);
 170 
 171         Source source = Source.instance(context);
 172         allowReifiableTypesInInstanceof = Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source);
 173         allowRecords = Feature.RECORDS.allowedInSource(source);
 174         allowPatternSwitch = (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH)) &&
 175                              Feature.PATTERN_SWITCH.allowedInSource(source);
 176         allowUnconditionalPatternsInstanceOf =
 177                              Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.allowedInSource(source);
 178         sourceName = source.name;
 179         useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
 180 
 181         statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
 182         varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
 183         unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
 184         methodAttrInfo = new MethodAttrInfo();
 185         unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
 186         unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
 187         recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
 188         initBlockType = new MethodType(List.nil(), syms.voidType, List.nil(), syms.methodClass);
 189         allowValueClasses = (!preview.isPreview(Feature.VALUE_CLASSES) || preview.isEnabled()) &&
 190                 Feature.VALUE_CLASSES.allowedInSource(source);
 191     }
 192 
 193     /** Switch: reifiable types in instanceof enabled?
 194      */
 195     boolean allowReifiableTypesInInstanceof;
 196 
 197     /** Are records allowed
 198      */
 199     private final boolean allowRecords;
 200 
 201     /** Are patterns in switch allowed
 202      */
 203     private final boolean allowPatternSwitch;
 204 
 205     /** Are unconditional patterns in instanceof allowed
 206      */
 207     private final boolean allowUnconditionalPatternsInstanceOf;
 208 
 209     /** Are value classes allowed
 210      */
 211     private final boolean allowValueClasses;
 212 
 213     /**
 214      * Switch: warn about use of variable before declaration?
 215      * RFE: 6425594
 216      */
 217     boolean useBeforeDeclarationWarning;
 218 
 219     /**
 220      * Switch: name of source level; used for error reporting.
 221      */
 222     String sourceName;
 223 
 224     /** Check kind and type of given tree against protokind and prototype.
 225      *  If check succeeds, store type in tree and return it.
 226      *  If check fails, store errType in tree and return it.
 227      *  No checks are performed if the prototype is a method type.
 228      *  It is not necessary in this case since we know that kind and type
 229      *  are correct.
 230      *
 231      *  @param tree     The tree whose kind and type is checked
 232      *  @param found    The computed type of the tree
 233      *  @param ownkind  The computed kind of the tree
 234      *  @param resultInfo  The expected result of the tree
 235      */
 236     Type check(final JCTree tree,
 237                final Type found,
 238                final KindSelector ownkind,
 239                final ResultInfo resultInfo) {
 240         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
 241         Type owntype;
 242         boolean shouldCheck = !found.hasTag(ERROR) &&
 243                 !resultInfo.pt.hasTag(METHOD) &&
 244                 !resultInfo.pt.hasTag(FORALL);
 245         if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
 246             log.error(tree.pos(),
 247                       Errors.UnexpectedType(resultInfo.pkind.kindNames(),
 248                                             ownkind.kindNames()));
 249             owntype = types.createErrorType(found);
 250         } else if (inferenceContext.free(found)) {
 251             //delay the check if there are inference variables in the found type
 252             //this means we are dealing with a partially inferred poly expression
 253             owntype = shouldCheck ? resultInfo.pt : found;
 254             if (resultInfo.checkMode.installPostInferenceHook()) {
 255                 inferenceContext.addFreeTypeListener(List.of(found),
 256                         instantiatedContext -> {
 257                             ResultInfo pendingResult =
 258                                     resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
 259                             check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
 260                         });
 261             }
 262         } else {
 263             owntype = shouldCheck ?
 264             resultInfo.check(tree, found) :
 265             found;
 266         }
 267         if (resultInfo.checkMode.updateTreeType()) {
 268             tree.type = owntype;
 269         }
 270         return owntype;
 271     }
 272 
 273     /** Is given blank final variable assignable, i.e. in a scope where it
 274      *  may be assigned to even though it is final?
 275      *  @param v      The blank final variable.
 276      *  @param env    The current environment.
 277      */
 278     boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
 279         Symbol owner = env.info.scope.owner;
 280            // owner refers to the innermost variable, method or
 281            // initializer block declaration at this point.
 282         boolean isAssignable =
 283             v.owner == owner
 284             ||
 285             ((owner.name == names.init ||    // i.e. we are in a constructor
 286               owner.kind == VAR ||           // i.e. we are in a variable initializer
 287               (owner.flags() & BLOCK) != 0)  // i.e. we are in an initializer block
 288              &&
 289              v.owner == owner.owner
 290              &&
 291              ((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
 292         boolean insideCompactConstructor = env.enclMethod != null && TreeInfo.isCompactConstructor(env.enclMethod);
 293         return isAssignable & !insideCompactConstructor;
 294     }
 295 
 296     /** Check that variable can be assigned to.
 297      *  @param pos    The current source code position.
 298      *  @param v      The assigned variable
 299      *  @param base   If the variable is referred to in a Select, the part
 300      *                to the left of the `.', null otherwise.
 301      *  @param env    The current environment.
 302      */
 303     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
 304         if (v.name == names._this) {
 305             log.error(pos, Errors.CantAssignValToThis);
 306         } else if ((v.flags() & FINAL) != 0 &&
 307             ((v.flags() & HASINIT) != 0
 308              ||
 309              !((base == null ||
 310                TreeInfo.isThisQualifier(base)) &&
 311                isAssignableAsBlankFinal(v, env)))) {
 312             if (v.isResourceVariable()) { //TWR resource
 313                 log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
 314             } else {
 315                 log.error(pos, Errors.CantAssignValToVar(Flags.toSource(v.flags() & (STATIC | FINAL)), v));
 316             }
 317         }
 318     }
 319 
 320     /** Does tree represent a static reference to an identifier?
 321      *  It is assumed that tree is either a SELECT or an IDENT.
 322      *  We have to weed out selects from non-type names here.
 323      *  @param tree    The candidate tree.
 324      */
 325     boolean isStaticReference(JCTree tree) {
 326         if (tree.hasTag(SELECT)) {
 327             Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
 328             if (lsym == null || lsym.kind != TYP) {
 329                 return false;
 330             }
 331         }
 332         return true;
 333     }
 334 
 335     /** Is this symbol a type?
 336      */
 337     static boolean isType(Symbol sym) {
 338         return sym != null && sym.kind == TYP;
 339     }
 340 
 341     /** Attribute a parsed identifier.
 342      * @param tree Parsed identifier name
 343      * @param topLevel The toplevel to use
 344      */
 345     public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
 346         Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
 347         localEnv.enclClass = make.ClassDef(make.Modifiers(0),
 348                                            syms.errSymbol.name,
 349                                            null, null, null, null);
 350         localEnv.enclClass.sym = syms.errSymbol;
 351         return attribIdent(tree, localEnv);
 352     }
 353 
 354     /** Attribute a parsed identifier.
 355      * @param tree Parsed identifier name
 356      * @param env The env to use
 357      */
 358     public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
 359         return tree.accept(identAttributer, env);
 360     }
 361     // where
 362         private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
 363         private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
 364             @Override @DefinedBy(Api.COMPILER_TREE)
 365             public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
 366                 Symbol site = visit(node.getExpression(), env);
 367                 if (site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
 368                     return site;
 369                 Name name = (Name)node.getIdentifier();
 370                 if (site.kind == PCK) {
 371                     env.toplevel.packge = (PackageSymbol)site;
 372                     return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
 373                             KindSelector.TYP_PCK);
 374                 } else {
 375                     env.enclClass.sym = (ClassSymbol)site;
 376                     return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
 377                 }
 378             }
 379 
 380             @Override @DefinedBy(Api.COMPILER_TREE)
 381             public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
 382                 return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
 383             }
 384         }
 385 
 386     public Type coerce(Type etype, Type ttype) {
 387         return cfolder.coerce(etype, ttype);
 388     }
 389 
 390     public Type attribType(JCTree node, TypeSymbol sym) {
 391         Env<AttrContext> env = typeEnvs.get(sym);
 392         Env<AttrContext> localEnv = env.dup(node, env.info.dup());
 393         return attribTree(node, localEnv, unknownTypeInfo);
 394     }
 395 
 396     public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
 397         // Attribute qualifying package or class.
 398         JCFieldAccess s = tree.qualid;
 399         return attribTree(s.selected, env,
 400                           new ResultInfo(tree.staticImport ?
 401                                          KindSelector.TYP : KindSelector.TYP_PCK,
 402                        Type.noType));
 403     }
 404 
 405     public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
 406         return attribToTree(expr, env, tree, unknownExprInfo);
 407     }
 408 
 409     public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
 410         return attribToTree(stmt, env, tree, statInfo);
 411     }
 412 
 413     private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
 414         breakTree = tree;
 415         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
 416         try {
 417             deferredAttr.attribSpeculative(root, env, resultInfo,
 418                     null, DeferredAttr.AttributionMode.ATTRIB_TO_TREE,
 419                     argumentAttr.withLocalCacheContext());
 420             attrRecover.doRecovery();
 421         } catch (BreakAttr b) {
 422             return b.env;
 423         } catch (AssertionError ae) {
 424             if (ae.getCause() instanceof BreakAttr breakAttr) {
 425                 return breakAttr.env;
 426             } else {
 427                 throw ae;
 428             }
 429         } finally {
 430             breakTree = null;
 431             log.useSource(prev);
 432         }
 433         return env;
 434     }
 435 
 436     private JCTree breakTree = null;
 437 
 438     private static class BreakAttr extends RuntimeException {
 439         static final long serialVersionUID = -6924771130405446405L;
 440         private transient Env<AttrContext> env;
 441         private BreakAttr(Env<AttrContext> env) {
 442             this.env = env;
 443         }
 444     }
 445 
 446     /**
 447      * Mode controlling behavior of Attr.Check
 448      */
 449     enum CheckMode {
 450 
 451         NORMAL,
 452 
 453         /**
 454          * Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
 455          * that the captured var cache in {@code InferenceContext} will be used in read-only
 456          * mode when performing inference checks.
 457          */
 458         NO_TREE_UPDATE {
 459             @Override
 460             public boolean updateTreeType() {
 461                 return false;
 462             }
 463         },
 464         /**
 465          * Mode signalling that caller will manage free types in tree decorations.
 466          */
 467         NO_INFERENCE_HOOK {
 468             @Override
 469             public boolean installPostInferenceHook() {
 470                 return false;
 471             }
 472         };
 473 
 474         public boolean updateTreeType() {
 475             return true;
 476         }
 477         public boolean installPostInferenceHook() {
 478             return true;
 479         }
 480     }
 481 
 482 
 483     class ResultInfo {
 484         final KindSelector pkind;
 485         final Type pt;
 486         final CheckContext checkContext;
 487         final CheckMode checkMode;
 488 
 489         ResultInfo(KindSelector pkind, Type pt) {
 490             this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
 491         }
 492 
 493         ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
 494             this(pkind, pt, chk.basicHandler, checkMode);
 495         }
 496 
 497         protected ResultInfo(KindSelector pkind,
 498                              Type pt, CheckContext checkContext) {
 499             this(pkind, pt, checkContext, CheckMode.NORMAL);
 500         }
 501 
 502         protected ResultInfo(KindSelector pkind,
 503                              Type pt, CheckContext checkContext, CheckMode checkMode) {
 504             this.pkind = pkind;
 505             this.pt = pt;
 506             this.checkContext = checkContext;
 507             this.checkMode = checkMode;
 508         }
 509 
 510         /**
 511          * Should {@link Attr#attribTree} use the {@code ArgumentAttr} visitor instead of this one?
 512          * @param tree The tree to be type-checked.
 513          * @return true if {@code ArgumentAttr} should be used.
 514          */
 515         protected boolean needsArgumentAttr(JCTree tree) { return false; }
 516 
 517         protected Type check(final DiagnosticPosition pos, final Type found) {
 518             return chk.checkType(pos, found, pt, checkContext);
 519         }
 520 
 521         protected ResultInfo dup(Type newPt) {
 522             return new ResultInfo(pkind, newPt, checkContext, checkMode);
 523         }
 524 
 525         protected ResultInfo dup(CheckContext newContext) {
 526             return new ResultInfo(pkind, pt, newContext, checkMode);
 527         }
 528 
 529         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 530             return new ResultInfo(pkind, newPt, newContext, checkMode);
 531         }
 532 
 533         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 534             return new ResultInfo(pkind, newPt, newContext, newMode);
 535         }
 536 
 537         protected ResultInfo dup(CheckMode newMode) {
 538             return new ResultInfo(pkind, pt, checkContext, newMode);
 539         }
 540 
 541         @Override
 542         public String toString() {
 543             if (pt != null) {
 544                 return pt.toString();
 545             } else {
 546                 return "";
 547             }
 548         }
 549     }
 550 
 551     class MethodAttrInfo extends ResultInfo {
 552         public MethodAttrInfo() {
 553             this(chk.basicHandler);
 554         }
 555 
 556         public MethodAttrInfo(CheckContext checkContext) {
 557             super(KindSelector.VAL, Infer.anyPoly, checkContext);
 558         }
 559 
 560         @Override
 561         protected boolean needsArgumentAttr(JCTree tree) {
 562             return true;
 563         }
 564 
 565         protected ResultInfo dup(Type newPt) {
 566             throw new IllegalStateException();
 567         }
 568 
 569         protected ResultInfo dup(CheckContext newContext) {
 570             return new MethodAttrInfo(newContext);
 571         }
 572 
 573         protected ResultInfo dup(Type newPt, CheckContext newContext) {
 574             throw new IllegalStateException();
 575         }
 576 
 577         protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
 578             throw new IllegalStateException();
 579         }
 580 
 581         protected ResultInfo dup(CheckMode newMode) {
 582             throw new IllegalStateException();
 583         }
 584     }
 585 
 586     class RecoveryInfo extends ResultInfo {
 587 
 588         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
 589             this(deferredAttrContext, Type.recoveryType);
 590         }
 591 
 592         public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
 593             super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
 594                 @Override
 595                 public DeferredAttr.DeferredAttrContext deferredAttrContext() {
 596                     return deferredAttrContext;
 597                 }
 598                 @Override
 599                 public boolean compatible(Type found, Type req, Warner warn) {
 600                     return true;
 601                 }
 602                 @Override
 603                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
 604                     boolean needsReport = pt == Type.recoveryType ||
 605                             (details.getDiagnosticPosition() != null &&
 606                             details.getDiagnosticPosition().getTree().hasTag(LAMBDA));
 607                     if (needsReport) {
 608                         chk.basicHandler.report(pos, details);
 609                     }
 610                 }
 611             });
 612         }
 613     }
 614 
 615     final ResultInfo statInfo;
 616     final ResultInfo varAssignmentInfo;
 617     final ResultInfo methodAttrInfo;
 618     final ResultInfo unknownExprInfo;
 619     final ResultInfo unknownTypeInfo;
 620     final ResultInfo unknownTypeExprInfo;
 621     final ResultInfo recoveryInfo;
 622     final MethodType initBlockType;
 623 
 624     Type pt() {
 625         return resultInfo.pt;
 626     }
 627 
 628     KindSelector pkind() {
 629         return resultInfo.pkind;
 630     }
 631 
 632 /* ************************************************************************
 633  * Visitor methods
 634  *************************************************************************/
 635 
 636     /** Visitor argument: the current environment.
 637      */
 638     Env<AttrContext> env;
 639 
 640     /** Visitor argument: the currently expected attribution result.
 641      */
 642     ResultInfo resultInfo;
 643 
 644     /** Visitor result: the computed type.
 645      */
 646     Type result;
 647 
 648     MatchBindings matchBindings = MatchBindingsComputer.EMPTY;
 649 
 650     /** Visitor method: attribute a tree, catching any completion failure
 651      *  exceptions. Return the tree's type.
 652      *
 653      *  @param tree    The tree to be visited.
 654      *  @param env     The environment visitor argument.
 655      *  @param resultInfo   The result info visitor argument.
 656      */
 657     Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
 658         Env<AttrContext> prevEnv = this.env;
 659         ResultInfo prevResult = this.resultInfo;
 660         try {
 661             this.env = env;
 662             this.resultInfo = resultInfo;
 663             if (resultInfo.needsArgumentAttr(tree)) {
 664                 result = argumentAttr.attribArg(tree, env);
 665             } else {
 666                 tree.accept(this);
 667             }
 668             matchBindings = matchBindingsComputer.finishBindings(tree,
 669                                                                  matchBindings);
 670             if (tree == breakTree &&
 671                     resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
 672                 breakTreeFound(copyEnv(env));
 673             }
 674             return result;
 675         } catch (CompletionFailure ex) {
 676             tree.type = syms.errType;
 677             return chk.completionError(tree.pos(), ex);
 678         } finally {
 679             this.env = prevEnv;
 680             this.resultInfo = prevResult;
 681         }
 682     }
 683 
 684     protected void breakTreeFound(Env<AttrContext> env) {
 685         throw new BreakAttr(env);
 686     }
 687 
 688     Env<AttrContext> copyEnv(Env<AttrContext> env) {
 689         Env<AttrContext> newEnv =
 690                 env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
 691         if (newEnv.outer != null) {
 692             newEnv.outer = copyEnv(newEnv.outer);
 693         }
 694         return newEnv;
 695     }
 696 
 697     WriteableScope copyScope(WriteableScope sc) {
 698         WriteableScope newScope = WriteableScope.create(sc.owner);
 699         List<Symbol> elemsList = List.nil();
 700         for (Symbol sym : sc.getSymbols()) {
 701             elemsList = elemsList.prepend(sym);
 702         }
 703         for (Symbol s : elemsList) {
 704             newScope.enter(s);
 705         }
 706         return newScope;
 707     }
 708 
 709     /** Derived visitor method: attribute an expression tree.
 710      */
 711     public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
 712         return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
 713     }
 714 
 715     /** Derived visitor method: attribute an expression tree with
 716      *  no constraints on the computed type.
 717      */
 718     public Type attribExpr(JCTree tree, Env<AttrContext> env) {
 719         return attribTree(tree, env, unknownExprInfo);
 720     }
 721 
 722     /** Derived visitor method: attribute a type tree.
 723      */
 724     public Type attribType(JCTree tree, Env<AttrContext> env) {
 725         Type result = attribType(tree, env, Type.noType);
 726         return result;
 727     }
 728 
 729     /** Derived visitor method: attribute a type tree.
 730      */
 731     Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
 732         Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
 733         return result;
 734     }
 735 
 736     /** Derived visitor method: attribute a statement or definition tree.
 737      */
 738     public Type attribStat(JCTree tree, Env<AttrContext> env) {
 739         Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
 740         Type result = attribTree(tree, env, statInfo);
 741         analyzer.analyzeIfNeeded(tree, analyzeEnv);
 742         attrRecover.doRecovery();
 743         return result;
 744     }
 745 
 746     /** Attribute a list of expressions, returning a list of types.
 747      */
 748     List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
 749         ListBuffer<Type> ts = new ListBuffer<>();
 750         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 751             ts.append(attribExpr(l.head, env, pt));
 752         return ts.toList();
 753     }
 754 
 755     /** Attribute a list of statements, returning nothing.
 756      */
 757     <T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
 758         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
 759             attribStat(l.head, env);
 760     }
 761 
 762     /** Attribute the arguments in a method call, returning the method kind.
 763      */
 764     KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
 765         KindSelector kind = initialKind;
 766         for (JCExpression arg : trees) {
 767             Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, methodAttrInfo));
 768             if (argtype.hasTag(DEFERRED)) {
 769                 kind = KindSelector.of(KindSelector.POLY, kind);
 770             }
 771             argtypes.append(argtype);
 772         }
 773         return kind;
 774     }
 775 
 776     /** Attribute a type argument list, returning a list of types.
 777      *  Caller is responsible for calling checkRefTypes.
 778      */
 779     List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
 780         ListBuffer<Type> argtypes = new ListBuffer<>();
 781         for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
 782             argtypes.append(attribType(l.head, env));
 783         return argtypes.toList();
 784     }
 785 
 786     /** Attribute a type argument list, returning a list of types.
 787      *  Check that all the types are references.
 788      */
 789     List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
 790         List<Type> types = attribAnyTypes(trees, env);
 791         return chk.checkRefTypes(trees, types);
 792     }
 793 
 794     /**
 795      * Attribute type variables (of generic classes or methods).
 796      * Compound types are attributed later in attribBounds.
 797      * @param typarams the type variables to enter
 798      * @param env      the current environment
 799      */
 800     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
 801         for (JCTypeParameter tvar : typarams) {
 802             TypeVar a = (TypeVar)tvar.type;
 803             a.tsym.flags_field |= UNATTRIBUTED;
 804             a.setUpperBound(Type.noType);
 805             if (!tvar.bounds.isEmpty()) {
 806                 List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
 807                 for (JCExpression bound : tvar.bounds.tail)
 808                     bounds = bounds.prepend(attribType(bound, env));
 809                 types.setBounds(a, bounds.reverse());
 810             } else {
 811                 // if no bounds are given, assume a single bound of
 812                 // java.lang.Object.
 813                 types.setBounds(a, List.of(syms.objectType));
 814             }
 815             a.tsym.flags_field &= ~UNATTRIBUTED;
 816         }
 817         if (checkCyclic) {
 818             for (JCTypeParameter tvar : typarams) {
 819                 chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
 820             }
 821         }
 822     }
 823 
 824     /**
 825      * Attribute the type references in a list of annotations.
 826      */
 827     void attribAnnotationTypes(List<JCAnnotation> annotations,
 828                                Env<AttrContext> env) {
 829         for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
 830             JCAnnotation a = al.head;
 831             attribType(a.annotationType, env);
 832         }
 833     }
 834 
 835     /**
 836      * Attribute a "lazy constant value".
 837      *  @param env         The env for the const value
 838      *  @param variable    The initializer for the const value
 839      *  @param type        The expected type, or null
 840      *  @see VarSymbol#setLazyConstValue
 841      */
 842     public Object attribLazyConstantValue(Env<AttrContext> env,
 843                                       Env<AttrContext> enclosingEnv,
 844                                       JCVariableDecl variable,
 845                                       Type type) {
 846         final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
 847         try {
 848             doQueueScanTreeAndTypeAnnotateForVarInit(variable, enclosingEnv);
 849             Type itype = attribExpr(variable.init, env, type);
 850             if (variable.isImplicitlyTyped()) {
 851                 //fixup local variable type
 852                 type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype, variable.name);
 853             }
 854             if (itype.constValue() != null) {
 855                 return coerce(itype, type).constValue();
 856             } else {
 857                 return null;
 858             }
 859         } finally {
 860             log.useSource(prevSource);
 861         }
 862     }
 863 
 864     /** Attribute type reference in an `extends', `implements', or 'permits' clause.
 865      *  Supertypes of anonymous inner classes are usually already attributed.
 866      *
 867      *  @param tree              The tree making up the type reference.
 868      *  @param env               The environment current at the reference.
 869      *  @param classExpected     true if only a class is expected here.
 870      *  @param interfaceExpected true if only an interface is expected here.
 871      */
 872     Type attribBase(JCTree tree,
 873                     Env<AttrContext> env,
 874                     boolean classExpected,
 875                     boolean interfaceExpected,
 876                     boolean checkExtensible) {
 877         Type t = tree.type != null ?
 878             tree.type :
 879             attribType(tree, env);
 880         try {
 881             return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
 882         } catch (CompletionFailure ex) {
 883             chk.completionError(tree.pos(), ex);
 884             return t;
 885         }
 886     }
 887     Type checkBase(Type t,
 888                    JCTree tree,
 889                    Env<AttrContext> env,
 890                    boolean classExpected,
 891                    boolean interfaceExpected,
 892                    boolean checkExtensible) {
 893         final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
 894                 (((JCTypeApply) tree).clazz).pos() : tree.pos();
 895         if (t.tsym.isAnonymous()) {
 896             log.error(pos, Errors.CantInheritFromAnon);
 897             return types.createErrorType(t);
 898         }
 899         if (t.isErroneous())
 900             return t;
 901         if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
 902             // check that type variable is already visible
 903             if (t.getUpperBound() == null) {
 904                 log.error(pos, Errors.IllegalForwardRef);
 905                 return types.createErrorType(t);
 906             }
 907         } else {
 908             t = chk.checkClassType(pos, t, checkExtensible);
 909         }
 910         if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
 911             log.error(pos, Errors.IntfExpectedHere);
 912             // return errType is necessary since otherwise there might
 913             // be undetected cycles which cause attribution to loop
 914             return types.createErrorType(t);
 915         } else if (checkExtensible &&
 916                    classExpected &&
 917                    (t.tsym.flags() & INTERFACE) != 0) {
 918             log.error(pos, Errors.NoIntfExpectedHere);
 919             return types.createErrorType(t);
 920         }
 921         if (checkExtensible &&
 922             ((t.tsym.flags() & FINAL) != 0)) {
 923             log.error(pos,
 924                       Errors.CantInheritFromFinal(t.tsym));
 925         }
 926         chk.checkNonCyclic(pos, t);
 927         return t;
 928     }
 929 
 930     Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
 931         Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
 932         id.type = env.info.scope.owner.enclClass().type;
 933         id.sym = env.info.scope.owner.enclClass();
 934         return id.type;
 935     }
 936 
 937     public void visitClassDef(JCClassDecl tree) {
 938         Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
 939                 Optional.ofNullable(env.info.attributionMode.isSpeculative ?
 940                         argumentAttr.withLocalCacheContext() : null);
 941         boolean ctorProloguePrev = env.info.ctorPrologue;
 942         try {
 943             // Local and anonymous classes have not been entered yet, so we need to
 944             // do it now.
 945             if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
 946                 enter.classEnter(tree, env);
 947             } else {
 948                 // If this class declaration is part of a class level annotation,
 949                 // as in @MyAnno(new Object() {}) class MyClass {}, enter it in
 950                 // order to simplify later steps and allow for sensible error
 951                 // messages.
 952                 if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
 953                     enter.classEnter(tree, env);
 954             }
 955 
 956             ClassSymbol c = tree.sym;
 957             if (c == null) {
 958                 // exit in case something drastic went wrong during enter.
 959                 result = null;
 960             } else {
 961                 // make sure class has been completed:
 962                 c.complete();
 963 
 964                 // If a class declaration appears in a constructor prologue,
 965                 // that means it's either a local class or an anonymous class.
 966                 // Either way, there is no immediately enclosing instance.
 967                 if (ctorProloguePrev) {
 968                     c.flags_field |= NOOUTERTHIS;
 969                 }
 970                 attribClass(tree.pos(), c);
 971                 result = tree.type = c.type;
 972             }
 973         } finally {
 974             localCacheContext.ifPresent(LocalCacheContext::leave);
 975             env.info.ctorPrologue = ctorProloguePrev;
 976         }
 977     }
 978 
 979     public void visitMethodDef(JCMethodDecl tree) {
 980         MethodSymbol m = tree.sym;
 981         boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
 982 
 983         Lint lint = env.info.lint.augment(m);
 984         Lint prevLint = chk.setLint(lint);
 985         boolean ctorProloguePrev = env.info.ctorPrologue;
 986         Assert.check(!env.info.ctorPrologue);
 987         MethodSymbol prevMethod = chk.setMethod(m);
 988         try {
 989             chk.checkDeprecatedAnnotation(tree.pos(), m);
 990 
 991 
 992             // Create a new environment with local scope
 993             // for attributing the method.
 994             Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
 995             localEnv.info.lint = lint;
 996 
 997             attribStats(tree.typarams, localEnv);
 998 
 999             // If we override any other methods, check that we do so properly.
1000             // JLS ???
1001             if (m.isStatic()) {
1002                 chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
1003             } else {
1004                 chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
1005             }
1006             chk.checkOverride(env, tree, m);
1007 
1008             if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
1009                 log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
1010             }
1011 
1012             // Enter all type parameters into the local method scope.
1013             for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
1014                 localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
1015 
1016             ClassSymbol owner = env.enclClass.sym;
1017             if ((owner.flags() & ANNOTATION) != 0 &&
1018                     (tree.params.nonEmpty() ||
1019                     tree.recvparam != null))
1020                 log.error(tree.params.nonEmpty() ?
1021                         tree.params.head.pos() :
1022                         tree.recvparam.pos(),
1023                         Errors.IntfAnnotationMembersCantHaveParams);
1024 
1025             // Attribute all value parameters.
1026             for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1027                 attribStat(l.head, localEnv);
1028             }
1029 
1030             chk.checkVarargsMethodDecl(localEnv, tree);
1031 
1032             // Check that type parameters are well-formed.
1033             chk.validate(tree.typarams, localEnv);
1034 
1035             // Check that result type is well-formed.
1036             if (tree.restype != null && !tree.restype.type.hasTag(VOID)) {
1037                 chk.validate(tree.restype, localEnv);
1038             }
1039             chk.checkRequiresIdentity(tree, env.info.lint);
1040 
1041             // Check that receiver type is well-formed.
1042             if (tree.recvparam != null) {
1043                 // Use a new environment to check the receiver parameter.
1044                 // Otherwise I get "might not have been initialized" errors.
1045                 // Is there a better way?
1046                 Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
1047                 attribType(tree.recvparam, newEnv);
1048                 chk.validate(tree.recvparam, newEnv);
1049             }
1050 
1051             // Is this method a constructor?
1052             boolean isConstructor = TreeInfo.isConstructor(tree);
1053 
1054             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP) {
1055                 // lets find if this method is an accessor
1056                 Optional<? extends RecordComponent> recordComponent = env.enclClass.sym.getRecordComponents().stream()
1057                         .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
1058                 if (recordComponent.isPresent()) {
1059                     // the method is a user defined accessor lets check that everything is fine
1060                     if (!tree.sym.isPublic()) {
1061                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.MethodMustBePublic));
1062                     }
1063                     if (!types.isSameType(tree.sym.type.getReturnType(), recordComponent.get().type)) {
1064                         log.error(tree, Errors.InvalidAccessorMethodInRecord(env.enclClass.sym,
1065                                 Fragments.AccessorReturnTypeDoesntMatch(tree.sym, recordComponent.get())));
1066                     }
1067                     if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1068                         log.error(tree,
1069                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodCantThrowException));
1070                     }
1071                     if (!tree.typarams.isEmpty()) {
1072                         log.error(tree,
1073                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeGeneric));
1074                     }
1075                     if (tree.sym.isStatic()) {
1076                         log.error(tree,
1077                                 Errors.InvalidAccessorMethodInRecord(env.enclClass.sym, Fragments.AccessorMethodMustNotBeStatic));
1078                     }
1079                 }
1080 
1081                 if (isConstructor) {
1082                     // if this a constructor other than the canonical one
1083                     if ((tree.sym.flags_field & RECORD) == 0) {
1084                         if (!TreeInfo.hasConstructorCall(tree, names._this)) {
1085                             log.error(tree, Errors.NonCanonicalConstructorInvokeAnotherConstructor(env.enclClass.sym));
1086                         }
1087                     } else {
1088                         // but if it is the canonical:
1089 
1090                         /* if user generated, then it shouldn't:
1091                          *     - have an accessibility stricter than that of the record type
1092                          *     - explicitly invoke any other constructor
1093                          */
1094                         if ((tree.sym.flags_field & GENERATEDCONSTR) == 0) {
1095                             if (Check.protection(m.flags()) > Check.protection(env.enclClass.sym.flags())) {
1096                                 log.error(tree,
1097                                         (env.enclClass.sym.flags() & AccessFlags) == 0 ?
1098                                             Errors.InvalidCanonicalConstructorInRecord(
1099                                                 Fragments.Canonical,
1100                                                 env.enclClass.sym.name,
1101                                                 Fragments.CanonicalMustNotHaveStrongerAccess("package")
1102                                             ) :
1103                                             Errors.InvalidCanonicalConstructorInRecord(
1104                                                     Fragments.Canonical,
1105                                                     env.enclClass.sym.name,
1106                                                     Fragments.CanonicalMustNotHaveStrongerAccess(asFlagSet(env.enclClass.sym.flags() & AccessFlags))
1107                                             )
1108                                 );
1109                             }
1110 
1111                             if (!allowValueClasses && TreeInfo.hasAnyConstructorCall(tree)) {
1112                                 log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1113                                         Fragments.Canonical, env.enclClass.sym.name,
1114                                         Fragments.CanonicalMustNotContainExplicitConstructorInvocation));
1115                             }
1116                         }
1117 
1118                         // also we want to check that no type variables have been defined
1119                         if (!tree.typarams.isEmpty()) {
1120                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1121                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalMustNotDeclareTypeVariables));
1122                         }
1123 
1124                         /* and now we need to check that the constructor's arguments are exactly the same as those of the
1125                          * record components
1126                          */
1127                         List<? extends RecordComponent> recordComponents = env.enclClass.sym.getRecordComponents();
1128                         List<Type> recordFieldTypes = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.type);
1129                         for (JCVariableDecl param: tree.params) {
1130                             boolean paramIsVarArgs = (param.sym.flags_field & VARARGS) != 0;
1131                             if (!types.isSameType(param.type, recordFieldTypes.head) ||
1132                                     (recordComponents.head.isVarargs() != paramIsVarArgs)) {
1133                                 log.error(param, Errors.InvalidCanonicalConstructorInRecord(
1134                                         Fragments.Canonical, env.enclClass.sym.name,
1135                                         Fragments.TypeMustBeIdenticalToCorrespondingRecordComponentType));
1136                             }
1137                             recordComponents = recordComponents.tail;
1138                             recordFieldTypes = recordFieldTypes.tail;
1139                         }
1140                     }
1141                 }
1142             }
1143 
1144             // annotation method checks
1145             if ((owner.flags() & ANNOTATION) != 0) {
1146                 // annotation method cannot have throws clause
1147                 if (tree.thrown.nonEmpty()) {
1148                     log.error(tree.thrown.head.pos(),
1149                               Errors.ThrowsNotAllowedInIntfAnnotation);
1150                 }
1151                 // annotation method cannot declare type-parameters
1152                 if (tree.typarams.nonEmpty()) {
1153                     log.error(tree.typarams.head.pos(),
1154                               Errors.IntfAnnotationMembersCantHaveTypeParams);
1155                 }
1156                 // validate annotation method's return type (could be an annotation type)
1157                 chk.validateAnnotationType(tree.restype);
1158                 // ensure that annotation method does not clash with members of Object/Annotation
1159                 chk.validateAnnotationMethod(tree.pos(), m);
1160             }
1161 
1162             for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
1163                 chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
1164 
1165             if (tree.body == null) {
1166                 // Empty bodies are only allowed for
1167                 // abstract, native, or interface methods, or for methods
1168                 // in a retrofit signature class.
1169                 if (tree.defaultValue != null) {
1170                     if ((owner.flags() & ANNOTATION) == 0)
1171                         log.error(tree.pos(),
1172                                   Errors.DefaultAllowedInIntfAnnotationMember);
1173                 }
1174                 if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
1175                     log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract);
1176             } else {
1177                 if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
1178                     if ((owner.flags() & INTERFACE) != 0) {
1179                         log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
1180                     } else {
1181                         log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
1182                     }
1183                 } else if ((tree.mods.flags & NATIVE) != 0) {
1184                     log.error(tree.pos(), Errors.NativeMethCantHaveBody);
1185                 }
1186                 // Add an implicit super() call unless an explicit call to
1187                 // super(...) or this(...) is given
1188                 // or we are compiling class java.lang.Object.
1189                 boolean addedSuperInIdentityClass = false;
1190                 if (isConstructor && owner.type != syms.objectType) {
1191                     if (!TreeInfo.hasAnyConstructorCall(tree)) {
1192                         JCStatement supCall = make.at(tree.body.pos).Exec(make.Apply(List.nil(),
1193                                 make.Ident(names._super), make.Idents(List.nil())));
1194                         if (allowValueClasses && (owner.isValueClass() || owner.hasStrict() || ((owner.flags_field & RECORD) != 0))) {
1195                             tree.body.stats = tree.body.stats.append(supCall);
1196                         } else {
1197                             tree.body.stats = tree.body.stats.prepend(supCall);
1198                             addedSuperInIdentityClass = true;
1199                         }
1200                     } else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
1201                             (tree.mods.flags & GENERATEDCONSTR) == 0 &&
1202                             TreeInfo.hasConstructorCall(tree, names._super)) {
1203                         // enum constructors are not allowed to call super
1204                         // directly, so make sure there aren't any super calls
1205                         // in enum constructors, except in the compiler
1206                         // generated one.
1207                         log.error(tree.body.stats.head.pos(),
1208                                   Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
1209                     }
1210                     if (env.enclClass.sym.isRecord() && (tree.sym.flags_field & RECORD) != 0) { // we are seeing the canonical constructor
1211                         List<Name> recordComponentNames = TreeInfo.recordFields(env.enclClass).map(vd -> vd.sym.name);
1212                         List<Name> initParamNames = tree.sym.params.map(p -> p.name);
1213                         if (!initParamNames.equals(recordComponentNames)) {
1214                             log.error(tree, Errors.InvalidCanonicalConstructorInRecord(
1215                                     Fragments.Canonical, env.enclClass.sym.name, Fragments.CanonicalWithNameMismatch));
1216                         }
1217                         if (tree.sym.type.asMethodType().thrown != null && !tree.sym.type.asMethodType().thrown.isEmpty()) {
1218                             log.error(tree,
1219                                     Errors.InvalidCanonicalConstructorInRecord(
1220                                             TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical,
1221                                             env.enclClass.sym.name,
1222                                             Fragments.ThrowsClauseNotAllowedForCanonicalConstructor(
1223                                                     TreeInfo.isCompactConstructor(tree) ? Fragments.Compact : Fragments.Canonical)));
1224                         }
1225                     }
1226                 }
1227 
1228                 // Attribute all type annotations in the body
1229                 annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m);
1230                 annotate.flush();
1231 
1232                 // Start of constructor prologue (if not in java.lang.Object constructor)
1233                 localEnv.info.ctorPrologue = isConstructor && owner.type != syms.objectType;
1234 
1235                 // Attribute method body.
1236                 attribStat(tree.body, localEnv);
1237                 if (localEnv.info.ctorPrologue) {
1238                     boolean thisInvocation = false;
1239                     ListBuffer<JCTree> prologueCode = new ListBuffer<>();
1240                     for (JCTree stat : tree.body.stats) {
1241                         prologueCode.add(stat);
1242                         /* gather all the stats in the body until a `super` or `this` constructor invocation is found,
1243                          * including the constructor invocation, that way we don't need to worry in the visitor below if
1244                          * if we are dealing or not with prologue code
1245                          */
1246                         if (stat instanceof JCExpressionStatement expStmt &&
1247                                 expStmt.expr instanceof JCMethodInvocation mi &&
1248                                 TreeInfo.isConstructorCall(mi)) {
1249                             thisInvocation = TreeInfo.name(mi.meth) == names._this;
1250                             if (!addedSuperInIdentityClass || !allowValueClasses) {
1251                                 break;
1252                             }
1253                         }
1254                     }
1255                     if (!prologueCode.isEmpty()) {
1256                         CtorPrologueVisitor ctorPrologueVisitor = new CtorPrologueVisitor(localEnv,
1257                                 addedSuperInIdentityClass && allowValueClasses ?
1258                                         PrologueVisitorMode.WARNINGS_ONLY :
1259                                         thisInvocation ?
1260                                                 PrologueVisitorMode.THIS_CONSTRUCTOR :
1261                                                 PrologueVisitorMode.SUPER_CONSTRUCTOR);
1262                         ctorPrologueVisitor.scan(prologueCode.toList());
1263                     }
1264                 }
1265             }
1266 
1267             localEnv.info.scope.leave();
1268             result = tree.type = m.type;
1269         } finally {
1270             chk.setLint(prevLint);
1271             chk.setMethod(prevMethod);
1272             env.info.ctorPrologue = ctorProloguePrev;
1273         }
1274     }
1275 
1276     enum PrologueVisitorMode {
1277         WARNINGS_ONLY,
1278         SUPER_CONSTRUCTOR,
1279         THIS_CONSTRUCTOR
1280     }
1281 
1282     class CtorPrologueVisitor extends TreeScanner {
1283         Env<AttrContext> localEnv;
1284         PrologueVisitorMode mode;
1285 
1286         CtorPrologueVisitor(Env<AttrContext> localEnv, PrologueVisitorMode mode) {
1287             this.localEnv = localEnv;
1288             currentClassSym = localEnv.enclClass.sym;
1289             this.mode = mode;
1290         }
1291 
1292         boolean insideLambdaOrClassDef = false;
1293 
1294         @Override
1295         public void visitLambda(JCLambda lambda) {
1296             boolean previousInsideLambdaOrClassDef = insideLambdaOrClassDef;
1297             try {
1298                 insideLambdaOrClassDef = true;
1299                 super.visitLambda(lambda);
1300             } finally {
1301                 insideLambdaOrClassDef = previousInsideLambdaOrClassDef;
1302             }
1303         }
1304 
1305         ClassSymbol currentClassSym;
1306 
1307         @Override
1308         public void visitClassDef(JCClassDecl classDecl) {
1309             boolean previousInsideLambdaOrClassDef = insideLambdaOrClassDef;
1310             ClassSymbol previousClassSym = currentClassSym;
1311             try {
1312                 insideLambdaOrClassDef = true;
1313                 currentClassSym = classDecl.sym;
1314                 super.visitClassDef(classDecl);
1315             } finally {
1316                 insideLambdaOrClassDef = previousInsideLambdaOrClassDef;
1317                 currentClassSym = previousClassSym;
1318             }
1319         }
1320 
1321         private void reportPrologueError(JCTree tree, Symbol sym) {
1322             reportPrologueError(tree, sym, false);
1323         }
1324 
1325         private void reportPrologueError(JCTree tree, Symbol sym, boolean hasInit) {
1326             preview.checkSourceLevel(tree, Feature.FLEXIBLE_CONSTRUCTORS);
1327             if (mode != PrologueVisitorMode.WARNINGS_ONLY) {
1328                 if (hasInit) {
1329                     log.error(tree, Errors.CantAssignInitializedBeforeCtorCalled(sym));
1330                 } else {
1331                     log.error(tree, Errors.CantRefBeforeCtorCalled(sym));
1332                 }
1333             } else if (allowValueClasses) {
1334                 // issue lint warning
1335                 log.warning(tree, LintWarnings.WouldNotBeAllowedInPrologue(sym));
1336             }
1337         }
1338 
1339         @Override
1340         public void visitApply(JCMethodInvocation tree) {
1341             super.visitApply(tree);
1342             Name name = TreeInfo.name(tree.meth);
1343             boolean isConstructorCall = name == names._this || name == names._super;
1344             Symbol msym = TreeInfo.symbolFor(tree.meth);
1345             // is this an instance method call or an illegal constructor invocation like: `this.super()`?
1346             if (msym != null && // for erroneous invocations msym can be null, ignore those
1347                 (!isConstructorCall ||
1348                 isConstructorCall && tree.meth.hasTag(SELECT))) {
1349                 if (isEarlyReference(localEnv, tree.meth, msym))
1350                     reportPrologueError(tree.meth, msym);
1351             }
1352         }
1353 
1354         @Override
1355         public void visitIdent(JCIdent tree) {
1356             analyzeSymbol(tree);
1357         }
1358 
1359         boolean isIndexed = false;
1360 
1361         @Override
1362         public void visitIndexed(JCArrayAccess tree) {
1363             boolean previousIsIndexed = isIndexed;
1364             try {
1365                 isIndexed = true;
1366                 scan(tree.indexed);
1367             } finally {
1368                 isIndexed = previousIsIndexed;
1369             }
1370             scan(tree.index);
1371             if (mode == PrologueVisitorMode.SUPER_CONSTRUCTOR && isInstanceField(tree.indexed)) {
1372                 localProxyVarsGen.addFieldReadInPrologue(localEnv.enclMethod, TreeInfo.symbolFor(tree.indexed));
1373             }
1374         }
1375 
1376         @Override
1377         public void visitSelect(JCFieldAccess tree) {
1378             SelectScanner ss = new SelectScanner();
1379             ss.scan(tree);
1380             if (ss.scanLater == null) {
1381                 analyzeSymbol(tree);
1382             } else {
1383                 boolean prevLhs = isInLHS;
1384                 try {
1385                     isInLHS = false;
1386                     scan(ss.scanLater);
1387                 } finally {
1388                     isInLHS = prevLhs;
1389                 }
1390             }
1391             if (mode == PrologueVisitorMode.SUPER_CONSTRUCTOR) {
1392                 for (JCTree subtree : ss.selectorTrees) {
1393                     if (isInstanceField(subtree)) {
1394                         // we need to add a proxy for this one
1395                         localProxyVarsGen.addFieldReadInPrologue(localEnv.enclMethod, TreeInfo.symbolFor(subtree));
1396                     }
1397                 }
1398             }
1399         }
1400 
1401         boolean isInstanceField(JCTree tree) {
1402             Symbol sym = TreeInfo.symbolFor(tree);
1403             return (sym != null &&
1404                     !sym.isStatic() &&
1405                     sym.kind == VAR &&
1406                     sym.owner.kind == TYP &&
1407                     sym.name != names._this &&
1408                     sym.name != names._super &&
1409                     isEarlyReference(localEnv, tree, sym));
1410         }
1411 
1412         @Override
1413         public void visitNewClass(JCNewClass tree) {
1414             super.visitNewClass(tree);
1415             checkNewClassAndMethRefs(tree, tree.type);
1416         }
1417 
1418         @Override
1419         public void visitReference(JCMemberReference tree) {
1420             super.visitReference(tree);
1421             if (tree.getMode() == JCMemberReference.ReferenceMode.NEW) {
1422                 checkNewClassAndMethRefs(tree, tree.expr.type);
1423             }
1424         }
1425 
1426         void checkNewClassAndMethRefs(JCTree tree, Type t) {
1427             if (t.tsym.isEnclosedBy(localEnv.enclClass.sym) &&
1428                     !t.tsym.isStatic() &&
1429                     !t.tsym.isDirectlyOrIndirectlyLocal()) {
1430                 reportPrologueError(tree, t.getEnclosingType().tsym);
1431             }
1432         }
1433 
1434         /* if a symbol is in the LHS of an assignment expression we won't consider it as a candidate
1435          * for a proxy local variable later on
1436          */
1437         boolean isInLHS = false;
1438 
1439         @Override
1440         public void visitAssign(JCAssign tree) {
1441             boolean previousIsInLHS = isInLHS;
1442             try {
1443                 isInLHS = true;
1444                 scan(tree.lhs);
1445             } finally {
1446                 isInLHS = previousIsInLHS;
1447             }
1448             scan(tree.rhs);
1449         }
1450 
1451         @Override
1452         public void visitMethodDef(JCMethodDecl tree) {
1453             // ignore any declarative part, mainly to avoid scanning receiver parameters
1454             scan(tree.body);
1455         }
1456 
1457         void analyzeSymbol(JCTree tree) {
1458             Symbol sym = TreeInfo.symbolFor(tree);
1459             // make sure that there is a symbol and it is not static
1460             if (sym == null || sym.isStatic()) {
1461                 return;
1462             }
1463             if (isInLHS && !insideLambdaOrClassDef) {
1464                 // Check instance field assignments that appear in constructor prologues
1465                 if (isEarlyReference(localEnv, tree, sym)) {
1466                     // Field may not be inherited from a superclass
1467                     if (sym.owner != localEnv.enclClass.sym) {
1468                         reportPrologueError(tree, sym);
1469                         return;
1470                     }
1471                     // Field may not have an initializer
1472                     if ((sym.flags() & HASINIT) != 0) {
1473                         if (!localEnv.enclClass.sym.isValueClass() || !sym.type.hasTag(ARRAY) || !isIndexed) {
1474                             reportPrologueError(tree, sym, true);
1475                         }
1476                         return;
1477                     }
1478                     // cant reference an instance field before a this constructor
1479                     if (allowValueClasses && mode == PrologueVisitorMode.THIS_CONSTRUCTOR) {
1480                         reportPrologueError(tree, sym);
1481                         return;
1482                     }
1483                 }
1484                 return;
1485             }
1486             tree = TreeInfo.skipParens(tree);
1487             if (sym.kind == VAR && sym.owner.kind == TYP) {
1488                 if (sym.name == names._this || sym.name == names._super) {
1489                     // are we seeing something like `this` or `CurrentClass.this` or `SuperClass.super::foo`?
1490                     if (TreeInfo.isExplicitThisReference(
1491                             types,
1492                             (ClassType)localEnv.enclClass.sym.type,
1493                             tree)) {
1494                         reportPrologueError(tree, sym);
1495                     }
1496                 } else if (sym.kind == VAR && sym.owner.kind == TYP) { // now fields only
1497                     if (sym.owner != localEnv.enclClass.sym) {
1498                         if (localEnv.enclClass.sym.isSubClass(sym.owner, types) &&
1499                                 sym.isInheritedIn(localEnv.enclClass.sym, types)) {
1500                             /* if we are dealing with a field that doesn't belong to the current class, but the
1501                              * field is inherited, this is an error. Unless, the super class is also an outer
1502                              * class and the field's qualifier refers to the outer class
1503                              */
1504                             if (tree.hasTag(IDENT) ||
1505                                 TreeInfo.isExplicitThisReference(
1506                                         types,
1507                                         (ClassType)localEnv.enclClass.sym.type,
1508                                         ((JCFieldAccess)tree).selected)) {
1509                                 reportPrologueError(tree, sym);
1510                             }
1511                         }
1512                     } else if (isEarlyReference(localEnv, tree, sym)) {
1513                         /* now this is a `proper` instance field of the current class
1514                          * references to fields of identity classes which happen to have initializers are
1515                          * not allowed in the prologue
1516                          */
1517                         if (insideLambdaOrClassDef ||
1518                             (!localEnv.enclClass.sym.isValueClass() && (sym.flags_field & HASINIT) != 0))
1519                             reportPrologueError(tree, sym);
1520                         // we will need to generate a proxy for this field later on
1521                         if (!isInLHS) {
1522                             if (!allowValueClasses) {
1523                                 reportPrologueError(tree, sym);
1524                             } else {
1525                                 if (mode == PrologueVisitorMode.THIS_CONSTRUCTOR) {
1526                                     reportPrologueError(tree, sym);
1527                                 } else if (mode == PrologueVisitorMode.SUPER_CONSTRUCTOR) {
1528                                     localProxyVarsGen.addFieldReadInPrologue(localEnv.enclMethod, sym);
1529                                 }
1530                                 /* we do nothing in warnings only mode, as in that mode we are simulating what
1531                                  * the compiler would do in case the constructor code would be in the prologue
1532                                  * phase
1533                                  */
1534                             }
1535                         }
1536                     }
1537                 }
1538             }
1539         }
1540 
1541         /**
1542          * Determine if the symbol appearance constitutes an early reference to the current class.
1543          *
1544          * <p>
1545          * This means the symbol is an instance field, or method, of the current class and it appears
1546          * in an early initialization context of it (i.e., one of its constructor prologues).
1547          *
1548          * @param env    The current environment
1549          * @param tree   the AST referencing the variable
1550          * @param sym    The symbol
1551          */
1552         private boolean isEarlyReference(Env<AttrContext> env, JCTree tree, Symbol sym) {
1553             if ((sym.flags() & STATIC) == 0 &&
1554                     (sym.kind == VAR || sym.kind == MTH) &&
1555                     sym.isMemberOf(env.enclClass.sym, types)) {
1556                 // Allow "Foo.this.x" when "Foo" is (also) an outer class, as this refers to the outer instance
1557                 if (tree instanceof JCFieldAccess fa) {
1558                     return TreeInfo.isExplicitThisReference(types, (ClassType)env.enclClass.type, fa.selected);
1559                 } else if (currentClassSym != env.enclClass.sym) {
1560                     /* so we are inside a class, CI, in the prologue of an outer class, CO, and the symbol being
1561                      * analyzed has no qualifier. So if the symbol is a member of CI the reference is allowed,
1562                      * otherwise it is not.
1563                      * It could be that the reference to CI's member happens inside CI's own prologue, but that
1564                      * will be checked separately, when CI's prologue is analyzed.
1565                      */
1566                     return !sym.isMemberOf(currentClassSym, types);
1567                 }
1568                 return true;
1569             }
1570             return false;
1571         }
1572 
1573         /* scanner for a select expression, anything that is not a select or identifier
1574          * will be stored for further analysis
1575          */
1576         class SelectScanner extends DeferredAttr.FilterScanner {
1577             JCTree scanLater;
1578             java.util.List<JCTree> selectorTrees = new ArrayList<>();
1579 
1580             SelectScanner() {
1581                 super(Set.of(IDENT, SELECT, PARENS));
1582             }
1583 
1584             @Override
1585             public void visitSelect(JCFieldAccess tree) {
1586                 super.visitSelect(tree);
1587                 selectorTrees.add(tree.selected);
1588             }
1589 
1590             @Override
1591             void skip(JCTree tree) {
1592                 scanLater = tree;
1593             }
1594         }
1595     }
1596 
1597     public void visitVarDef(JCVariableDecl tree) {
1598         // Local variables have not been entered yet, so we need to do it now:
1599         if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
1600             if (tree.sym != null) {
1601                 // parameters have already been entered
1602                 env.info.scope.enter(tree.sym);
1603             } else {
1604                 if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
1605                     if (tree.init == null) {
1606                         //cannot use 'var' without initializer
1607                         log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
1608                         tree.vartype = make.at(tree.pos()).Erroneous();
1609                     } else {
1610                         Fragment msg = canInferLocalVarType(tree);
1611                         if (msg != null) {
1612                             //cannot use 'var' with initializer which require an explicit target
1613                             //(e.g. lambda, method reference, array initializer).
1614                             log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
1615                             tree.vartype = make.at(tree.pos()).Erroneous();
1616                         }
1617                     }
1618                 }
1619                 try {
1620                     annotate.blockAnnotations();
1621                     memberEnter.memberEnter(tree, env);
1622                 } finally {
1623                     annotate.unblockAnnotations();
1624                 }
1625             }
1626         } else {
1627             doQueueScanTreeAndTypeAnnotateForVarInit(tree, env);
1628         }
1629 
1630         VarSymbol v = tree.sym;
1631         Lint lint = env.info.lint.augment(v);
1632         Lint prevLint = chk.setLint(lint);
1633 
1634         // Check that the variable's declared type is well-formed.
1635         boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
1636                 ((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
1637                 (tree.sym.flags() & PARAMETER) != 0;
1638         chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
1639 
1640         try {
1641             v.getConstValue(); // ensure compile-time constant initializer is evaluated
1642             chk.checkDeprecatedAnnotation(tree.pos(), v);
1643 
1644             if (tree.init != null) {
1645                 if ((v.flags_field & FINAL) == 0 ||
1646                     !memberEnter.needsLazyConstValue(tree.init)) {
1647                     // Not a compile-time constant
1648                     // Attribute initializer in a new environment
1649                     // with the declared variable as owner.
1650                     // Check that initializer conforms to variable's declared type.
1651                     Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
1652                     initEnv.info.lint = lint;
1653                     // In order to catch self-references, we set the variable's
1654                     // declaration position to maximal possible value, effectively
1655                     // marking the variable as undefined.
1656                     initEnv.info.enclVar = v;
1657                     boolean previousCtorPrologue = initEnv.info.ctorPrologue;
1658                     try {
1659                         if (v.owner.kind == TYP && !v.isStatic() && v.isStrict()) {
1660                             // strict instance initializer in a value class
1661                             initEnv.info.ctorPrologue = true;
1662                         }
1663                         attribExpr(tree.init, initEnv, v.type);
1664                         if (tree.isImplicitlyTyped()) {
1665                             //fixup local variable type
1666                             v.type = chk.checkLocalVarType(tree, tree.init.type, tree.name);
1667                         }
1668                         if (allowValueClasses && v.owner.kind == TYP && !v.isStatic()) {
1669                             // strict field initializers are inlined in constructor's prologues
1670                             CtorPrologueVisitor ctorPrologueVisitor = new CtorPrologueVisitor(initEnv,
1671                                     !v.isStrict() ? PrologueVisitorMode.WARNINGS_ONLY : PrologueVisitorMode.SUPER_CONSTRUCTOR);
1672                             ctorPrologueVisitor.scan(tree.init);
1673                         }
1674                     } finally {
1675                         initEnv.info.ctorPrologue = previousCtorPrologue;
1676                     }
1677                 }
1678                 if (tree.isImplicitlyTyped()) {
1679                     setSyntheticVariableType(tree, v.type);
1680                 }
1681             }
1682             result = tree.type = v.type;
1683             if (env.enclClass.sym.isRecord() && tree.sym.owner.kind == TYP && !v.isStatic()) {
1684                 if (isNonArgsMethodInObject(v.name)) {
1685                     log.error(tree, Errors.IllegalRecordComponentName(v));
1686                 }
1687             }
1688             chk.checkRequiresIdentity(tree, env.info.lint);
1689         }
1690         finally {
1691             chk.setLint(prevLint);
1692         }
1693     }
1694 
1695     private void doQueueScanTreeAndTypeAnnotateForVarInit(JCVariableDecl tree, Env<AttrContext> env) {
1696         if (tree.init != null &&
1697             (tree.mods.flags & Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED) == 0 &&
1698             env.info.scope.owner.kind != MTH && env.info.scope.owner.kind != VAR) {
1699             tree.mods.flags |= Flags.FIELD_INIT_TYPE_ANNOTATIONS_QUEUED;
1700             // Field initializer expression need to be entered.
1701             annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym);
1702             annotate.flush();
1703         }
1704     }
1705 
1706     private boolean isNonArgsMethodInObject(Name name) {
1707         for (Symbol s : syms.objectType.tsym.members().getSymbolsByName(name, s -> s.kind == MTH)) {
1708             if (s.type.getParameterTypes().isEmpty()) {
1709                 return true;
1710             }
1711         }
1712         return false;
1713     }
1714 
1715     Fragment canInferLocalVarType(JCVariableDecl tree) {
1716         LocalInitScanner lis = new LocalInitScanner();
1717         lis.scan(tree.init);
1718         return lis.badInferenceMsg;
1719     }
1720 
1721     static class LocalInitScanner extends TreeScanner {
1722         Fragment badInferenceMsg = null;
1723         boolean needsTarget = true;
1724 
1725         @Override
1726         public void visitNewArray(JCNewArray tree) {
1727             if (tree.elemtype == null && needsTarget) {
1728                 badInferenceMsg = Fragments.LocalArrayMissingTarget;
1729             }
1730         }
1731 
1732         @Override
1733         public void visitLambda(JCLambda tree) {
1734             if (needsTarget) {
1735                 badInferenceMsg = Fragments.LocalLambdaMissingTarget;
1736             }
1737         }
1738 
1739         @Override
1740         public void visitTypeCast(JCTypeCast tree) {
1741             boolean prevNeedsTarget = needsTarget;
1742             try {
1743                 needsTarget = false;
1744                 super.visitTypeCast(tree);
1745             } finally {
1746                 needsTarget = prevNeedsTarget;
1747             }
1748         }
1749 
1750         @Override
1751         public void visitReference(JCMemberReference tree) {
1752             if (needsTarget) {
1753                 badInferenceMsg = Fragments.LocalMrefMissingTarget;
1754             }
1755         }
1756 
1757         @Override
1758         public void visitNewClass(JCNewClass tree) {
1759             boolean prevNeedsTarget = needsTarget;
1760             try {
1761                 needsTarget = false;
1762                 super.visitNewClass(tree);
1763             } finally {
1764                 needsTarget = prevNeedsTarget;
1765             }
1766         }
1767 
1768         @Override
1769         public void visitApply(JCMethodInvocation tree) {
1770             boolean prevNeedsTarget = needsTarget;
1771             try {
1772                 needsTarget = false;
1773                 super.visitApply(tree);
1774             } finally {
1775                 needsTarget = prevNeedsTarget;
1776             }
1777         }
1778     }
1779 
1780     public void visitSkip(JCSkip tree) {
1781         result = null;
1782     }
1783 
1784     public void visitBlock(JCBlock tree) {
1785         if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
1786             // Block is a static or instance initializer;
1787             // let the owner of the environment be a freshly
1788             // created BLOCK-method.
1789             Symbol fakeOwner =
1790                 new MethodSymbol(tree.flags | BLOCK |
1791                     env.info.scope.owner.flags() & STRICTFP, names.empty, initBlockType,
1792                     env.info.scope.owner);
1793             final Env<AttrContext> localEnv =
1794                 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
1795 
1796             if ((tree.flags & STATIC) != 0) {
1797                 localEnv.info.staticLevel++;
1798             } else {
1799                 localEnv.info.instanceInitializerBlock = true;
1800             }
1801             // Attribute all type annotations in the block
1802             annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner);
1803             annotate.flush();
1804             attribStats(tree.stats, localEnv);
1805 
1806             {
1807                 // Store init and clinit type annotations with the ClassSymbol
1808                 // to allow output in Gen.normalizeDefs.
1809                 ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
1810                 List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
1811                 if ((tree.flags & STATIC) != 0) {
1812                     cs.appendClassInitTypeAttributes(tas);
1813                 } else {
1814                     cs.appendInitTypeAttributes(tas);
1815                 }
1816             }
1817         } else {
1818             // Create a new local environment with a local scope.
1819             Env<AttrContext> localEnv =
1820                 env.dup(tree, env.info.dup(env.info.scope.dup()));
1821             try {
1822                 attribStats(tree.stats, localEnv);
1823             } finally {
1824                 localEnv.info.scope.leave();
1825             }
1826         }
1827         result = null;
1828     }
1829 
1830     public void visitDoLoop(JCDoWhileLoop tree) {
1831         attribStat(tree.body, env.dup(tree));
1832         attribExpr(tree.cond, env, syms.booleanType);
1833         handleLoopConditionBindings(matchBindings, tree, tree.body);
1834         result = null;
1835     }
1836 
1837     public void visitWhileLoop(JCWhileLoop tree) {
1838         attribExpr(tree.cond, env, syms.booleanType);
1839         MatchBindings condBindings = matchBindings;
1840         // include condition's bindings when true in the body:
1841         Env<AttrContext> whileEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
1842         try {
1843             attribStat(tree.body, whileEnv.dup(tree));
1844         } finally {
1845             whileEnv.info.scope.leave();
1846         }
1847         handleLoopConditionBindings(condBindings, tree, tree.body);
1848         result = null;
1849     }
1850 
1851     public void visitForLoop(JCForLoop tree) {
1852         Env<AttrContext> loopEnv =
1853             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1854         MatchBindings condBindings = MatchBindingsComputer.EMPTY;
1855         try {
1856             attribStats(tree.init, loopEnv);
1857             if (tree.cond != null) {
1858                 attribExpr(tree.cond, loopEnv, syms.booleanType);
1859                 // include condition's bindings when true in the body and step:
1860                 condBindings = matchBindings;
1861             }
1862             Env<AttrContext> bodyEnv = bindingEnv(loopEnv, condBindings.bindingsWhenTrue);
1863             try {
1864                 bodyEnv.tree = tree; // before, we were not in loop!
1865                 attribStats(tree.step, bodyEnv);
1866                 attribStat(tree.body, bodyEnv);
1867             } finally {
1868                 bodyEnv.info.scope.leave();
1869             }
1870             result = null;
1871         }
1872         finally {
1873             loopEnv.info.scope.leave();
1874         }
1875         handleLoopConditionBindings(condBindings, tree, tree.body);
1876     }
1877 
1878     /**
1879      * Include condition's bindings when false after the loop, if cannot get out of the loop
1880      */
1881     private void handleLoopConditionBindings(MatchBindings condBindings,
1882                                              JCStatement loop,
1883                                              JCStatement loopBody) {
1884         if (condBindings.bindingsWhenFalse.nonEmpty() &&
1885             !breaksTo(env, loop, loopBody)) {
1886             addBindings2Scope(loop, condBindings.bindingsWhenFalse);
1887         }
1888     }
1889 
1890     private boolean breaksTo(Env<AttrContext> env, JCTree loop, JCTree body) {
1891         preFlow(body);
1892         return flow.breaksToTree(env, loop, body, make);
1893     }
1894 
1895     /**
1896      * Add given bindings to the current scope, unless there's a break to
1897      * an immediately enclosing labeled statement.
1898      */
1899     private void addBindings2Scope(JCStatement introducingStatement,
1900                                    List<BindingSymbol> bindings) {
1901         if (bindings.isEmpty()) {
1902             return ;
1903         }
1904 
1905         var searchEnv = env;
1906         while (searchEnv.tree instanceof JCLabeledStatement labeled &&
1907                labeled.body == introducingStatement) {
1908             if (breaksTo(env, labeled, labeled.body)) {
1909                 //breaking to an immediately enclosing labeled statement
1910                 return ;
1911             }
1912             searchEnv = searchEnv.next;
1913             introducingStatement = labeled;
1914         }
1915 
1916         //include condition's body when false after the while, if cannot get out of the loop
1917         bindings.forEach(env.info.scope::enter);
1918         bindings.forEach(BindingSymbol::preserveBinding);
1919     }
1920 
1921     public void visitForeachLoop(JCEnhancedForLoop tree) {
1922         Env<AttrContext> loopEnv =
1923             env.dup(env.tree, env.info.dup(env.info.scope.dup()));
1924         try {
1925             //the Formal Parameter of a for-each loop is not in the scope when
1926             //attributing the for-each expression; we mimic this by attributing
1927             //the for-each expression first (against original scope).
1928             Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
1929             chk.checkNonVoid(tree.pos(), exprType);
1930             Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
1931             if (elemtype == null) {
1932                 // or perhaps expr implements Iterable<T>?
1933                 Type base = types.asSuper(exprType, syms.iterableType.tsym);
1934                 if (base == null) {
1935                     log.error(tree.expr.pos(),
1936                               Errors.ForeachNotApplicableToType(exprType,
1937                                                                 Fragments.TypeReqArrayOrIterable));
1938                     elemtype = types.createErrorType(exprType);
1939                 } else {
1940                     List<Type> iterableParams = base.allparams();
1941                     elemtype = iterableParams.isEmpty()
1942                         ? syms.objectType
1943                         : types.wildUpperBound(iterableParams.head);
1944 
1945                     // Check the return type of the method iterator().
1946                     // This is the bare minimum we need to verify to make sure code generation doesn't crash.
1947                     Symbol iterSymbol = rs.resolveInternalMethod(tree.pos(),
1948                             loopEnv, types.skipTypeVars(exprType, false), names.iterator, List.nil(), List.nil());
1949                     if (types.asSuper(iterSymbol.type.getReturnType(), syms.iteratorType.tsym) == null) {
1950                         log.error(tree.pos(),
1951                                 Errors.ForeachNotApplicableToType(exprType, Fragments.TypeReqArrayOrIterable));
1952                     }
1953                 }
1954             }
1955             if (tree.var.isImplicitlyTyped()) {
1956                 Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
1957                 setSyntheticVariableType(tree.var, inferredType);
1958             }
1959             attribStat(tree.var, loopEnv);
1960             chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
1961             loopEnv.tree = tree; // before, we were not in loop!
1962             attribStat(tree.body, loopEnv);
1963             result = null;
1964         }
1965         finally {
1966             loopEnv.info.scope.leave();
1967         }
1968     }
1969 
1970     public void visitLabelled(JCLabeledStatement tree) {
1971         // Check that label is not used in an enclosing statement
1972         Env<AttrContext> env1 = env;
1973         while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
1974             if (env1.tree.hasTag(LABELLED) &&
1975                 ((JCLabeledStatement) env1.tree).label == tree.label) {
1976                 log.error(tree.pos(),
1977                           Errors.LabelAlreadyInUse(tree.label));
1978                 break;
1979             }
1980             env1 = env1.next;
1981         }
1982 
1983         attribStat(tree.body, env.dup(tree));
1984         result = null;
1985     }
1986 
1987     public void visitSwitch(JCSwitch tree) {
1988         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
1989             attribStats(c.stats, caseEnv);
1990         });
1991         result = null;
1992     }
1993 
1994     public void visitSwitchExpression(JCSwitchExpression tree) {
1995         boolean wrongContext = false;
1996 
1997         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
1998                 PolyKind.STANDALONE : PolyKind.POLY;
1999 
2000         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2001             //this means we are returning a poly conditional from void-compatible lambda expression
2002             resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
2003             resultInfo = recoveryInfo;
2004             wrongContext = true;
2005         }
2006 
2007         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2008                 unknownExprInfo :
2009                 resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
2010 
2011         ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
2012         ListBuffer<Type> caseTypes = new ListBuffer<>();
2013 
2014         handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
2015             caseEnv.info.yieldResult = condInfo;
2016             attribStats(c.stats, caseEnv);
2017             new TreeScanner() {
2018                 @Override
2019                 public void visitYield(JCYield brk) {
2020                     if (brk.target == tree) {
2021                         caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
2022                         caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
2023                     }
2024                     super.visitYield(brk);
2025                 }
2026 
2027                 @Override public void visitClassDef(JCClassDecl tree) {}
2028                 @Override public void visitLambda(JCLambda tree) {}
2029             }.scan(c.stats);
2030         });
2031 
2032         if (tree.cases.isEmpty()) {
2033             log.error(tree.pos(),
2034                       Errors.SwitchExpressionEmpty);
2035         } else if (caseTypes.isEmpty()) {
2036             log.error(tree.pos(),
2037                       Errors.SwitchExpressionNoResultExpressions);
2038         }
2039 
2040         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
2041 
2042         result = tree.type = wrongContext? types.createErrorType(pt()) : check(tree, owntype, KindSelector.VAL, resultInfo);
2043     }
2044     //where:
2045         CheckContext switchExpressionContext(CheckContext checkContext) {
2046             return new Check.NestedCheckContext(checkContext) {
2047                 //this will use enclosing check context to check compatibility of
2048                 //subexpression against target type; if we are in a method check context,
2049                 //depending on whether boxing is allowed, we could have incompatibilities
2050                 @Override
2051                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2052                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
2053                 }
2054             };
2055         }
2056 
2057     private void handleSwitch(JCTree switchTree,
2058                               JCExpression selector,
2059                               List<JCCase> cases,
2060                               BiConsumer<JCCase, Env<AttrContext>> attribCase) {
2061         Type seltype = attribExpr(selector, env);
2062         Type seltypeUnboxed = types.unboxedTypeOrType(seltype);
2063 
2064         Env<AttrContext> switchEnv =
2065             env.dup(switchTree, env.info.dup(env.info.scope.dup()));
2066 
2067         try {
2068             boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
2069             boolean stringSwitch = types.isSameType(seltype, syms.stringType);
2070             boolean booleanSwitch = types.isSameType(seltypeUnboxed, syms.booleanType);
2071             boolean errorEnumSwitch = TreeInfo.isErrorEnumSwitch(selector, cases);
2072             boolean intSwitch = types.isAssignable(seltype, syms.intType);
2073             boolean patternSwitch;
2074             if (seltype.isPrimitive() && !intSwitch) {
2075                 preview.checkSourceLevel(selector.pos(), Feature.PRIMITIVE_PATTERNS);
2076                 patternSwitch = true;
2077             }
2078             if (!enumSwitch && !stringSwitch && !errorEnumSwitch &&
2079                 !intSwitch) {
2080                 preview.checkSourceLevel(selector.pos(), Feature.PATTERN_SWITCH);
2081                 patternSwitch = true;
2082             } else {
2083                 patternSwitch = cases.stream()
2084                                      .flatMap(c -> c.labels.stream())
2085                                      .anyMatch(l -> l.hasTag(PATTERNCASELABEL) ||
2086                                                     TreeInfo.isNullCaseLabel(l));
2087             }
2088 
2089             // Attribute all cases and
2090             // check that there are no duplicate case labels or default clauses.
2091             Set<Object> constants = new HashSet<>(); // The set of case constants.
2092             boolean hasDefault = false;           // Is there a default label?
2093             boolean hasUnconditionalPattern = false; // Is there a unconditional pattern?
2094             boolean lastPatternErroneous = false; // Has the last pattern erroneous type?
2095             boolean hasNullPattern = false;       // Is there a null pattern?
2096             CaseTree.CaseKind caseKind = null;
2097             boolean wasError = false;
2098             JCCaseLabel unconditionalCaseLabel = null;
2099             for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
2100                 JCCase c = l.head;
2101                 if (caseKind == null) {
2102                     caseKind = c.caseKind;
2103                 } else if (caseKind != c.caseKind && !wasError) {
2104                     log.error(c.pos(),
2105                               Errors.SwitchMixingCaseTypes);
2106                     wasError = true;
2107                 }
2108                 MatchBindings currentBindings = null;
2109                 MatchBindings guardBindings = null;
2110                 for (List<JCCaseLabel> labels = c.labels; labels.nonEmpty(); labels = labels.tail) {
2111                     JCCaseLabel label = labels.head;
2112                     if (label instanceof JCConstantCaseLabel constLabel) {
2113                         JCExpression expr = constLabel.expr;
2114                         if (TreeInfo.isNull(expr)) {
2115                             preview.checkSourceLevel(expr.pos(), Feature.CASE_NULL);
2116                             if (hasNullPattern) {
2117                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
2118                             }
2119                             hasNullPattern = true;
2120                             attribExpr(expr, switchEnv, seltype);
2121                             matchBindings = new MatchBindings(matchBindings.bindingsWhenTrue, matchBindings.bindingsWhenFalse, true);
2122                         } else if (enumSwitch) {
2123                             Symbol sym = enumConstant(expr, seltype);
2124                             if (sym == null) {
2125                                 if (allowPatternSwitch) {
2126                                     attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
2127                                     Symbol enumSym = TreeInfo.symbol(expr);
2128                                     if (enumSym == null || !enumSym.isEnum() || enumSym.kind != VAR) {
2129                                         log.error(expr.pos(), Errors.EnumLabelMustBeEnumConstant);
2130                                     } else if (!constants.add(enumSym)) {
2131                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
2132                                     }
2133                                 } else {
2134                                     log.error(expr.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
2135                                 }
2136                             } else if (!constants.add(sym)) {
2137                                 log.error(label.pos(), Errors.DuplicateCaseLabel);
2138                             }
2139                         } else if (errorEnumSwitch) {
2140                             //error recovery: the selector is erroneous, and all the case labels
2141                             //are identifiers. This could be an enum switch - don't report resolve
2142                             //error for the case label:
2143                             var prevResolveHelper = rs.basicLogResolveHelper;
2144                             try {
2145                                 rs.basicLogResolveHelper = rs.silentLogResolveHelper;
2146                                 attribExpr(expr, switchEnv, seltype);
2147                             } finally {
2148                                 rs.basicLogResolveHelper = prevResolveHelper;
2149                             }
2150                         } else {
2151                             Type pattype = attribTree(expr, switchEnv, caseLabelResultInfo(seltype));
2152                             if (!pattype.hasTag(ERROR)) {
2153                                 if (pattype.constValue() == null) {
2154                                     Symbol s = TreeInfo.symbol(expr);
2155                                     if (s != null && s.kind == TYP) {
2156                                         log.error(expr.pos(),
2157                                                   Errors.PatternExpected);
2158                                     } else if (s == null || !s.isEnum()) {
2159                                         log.error(expr.pos(),
2160                                                   (stringSwitch ? Errors.StringConstReq
2161                                                                 : intSwitch ? Errors.ConstExprReq
2162                                                                             : Errors.PatternOrEnumReq));
2163                                     } else if (!constants.add(s)) {
2164                                         log.error(label.pos(), Errors.DuplicateCaseLabel);
2165                                     }
2166                                 }
2167                                 else {
2168                                     boolean isLongFloatDoubleOrBooleanConstant =
2169                                             pattype.getTag().isInSuperClassesOf(LONG) || pattype.getTag().equals(BOOLEAN);
2170                                     if (isLongFloatDoubleOrBooleanConstant) {
2171                                         preview.checkSourceLevel(label.pos(), Feature.PRIMITIVE_PATTERNS);
2172                                     }
2173                                     if (!stringSwitch && !intSwitch && !(isLongFloatDoubleOrBooleanConstant && types.isSameType(seltypeUnboxed, pattype))) {
2174                                         log.error(label.pos(), Errors.ConstantLabelNotCompatible(pattype, seltype));
2175                                     } else if (!constants.add(pattype.constValue())) {
2176                                         log.error(c.pos(), Errors.DuplicateCaseLabel);
2177                                     }
2178                                 }
2179                             }
2180                         }
2181                     } else if (label instanceof JCDefaultCaseLabel def) {
2182                         if (hasDefault) {
2183                             log.error(label.pos(), Errors.DuplicateDefaultLabel);
2184                         } else if (hasUnconditionalPattern) {
2185                             log.error(label.pos(), Errors.UnconditionalPatternAndDefault);
2186                         }  else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
2187                             log.error(label.pos(), Errors.DefaultAndBothBooleanValues);
2188                         }
2189                         hasDefault = true;
2190                         matchBindings = MatchBindingsComputer.EMPTY;
2191                     } else if (label instanceof JCPatternCaseLabel patternlabel) {
2192                         //pattern
2193                         JCPattern pat = patternlabel.pat;
2194                         attribExpr(pat, switchEnv, seltype);
2195                         Type primaryType = TreeInfo.primaryPatternType(pat);
2196 
2197                         if (primaryType.isPrimitive()) {
2198                             preview.checkSourceLevel(pat.pos(), Feature.PRIMITIVE_PATTERNS);
2199                         } else if (!primaryType.hasTag(TYPEVAR)) {
2200                             primaryType = chk.checkClassOrArrayType(pat.pos(), primaryType);
2201                         }
2202                         checkCastablePattern(pat.pos(), seltype, primaryType);
2203                         Type patternType = types.erasure(primaryType);
2204                         JCExpression guard = c.guard;
2205                         if (guardBindings == null && guard != null) {
2206                             MatchBindings afterPattern = matchBindings;
2207                             Env<AttrContext> bodyEnv = bindingEnv(switchEnv, matchBindings.bindingsWhenTrue);
2208                             try {
2209                                 attribExpr(guard, bodyEnv, syms.booleanType);
2210                             } finally {
2211                                 bodyEnv.info.scope.leave();
2212                             }
2213 
2214                             guardBindings = matchBindings;
2215                             matchBindings = afterPattern;
2216 
2217                             if (TreeInfo.isBooleanWithValue(guard, 0)) {
2218                                 log.error(guard.pos(), Errors.GuardHasConstantExpressionFalse);
2219                             }
2220                         }
2221                         boolean unguarded = TreeInfo.unguardedCase(c) && !pat.hasTag(RECORDPATTERN);
2222                         boolean unconditional =
2223                                 unguarded &&
2224                                 !patternType.isErroneous() &&
2225                                 types.isUnconditionallyExact(seltype, patternType);
2226                         if (unconditional) {
2227                             if (hasUnconditionalPattern) {
2228                                 log.error(pat.pos(), Errors.DuplicateUnconditionalPattern);
2229                             } else if (hasDefault) {
2230                                 log.error(pat.pos(), Errors.UnconditionalPatternAndDefault);
2231                             } else if (booleanSwitch && constants.containsAll(Set.of(0, 1))) {
2232                                 log.error(pat.pos(), Errors.UnconditionalPatternAndBothBooleanValues);
2233                             }
2234                             hasUnconditionalPattern = true;
2235                             unconditionalCaseLabel = label;
2236                         }
2237                         lastPatternErroneous = patternType.isErroneous();
2238                     } else {
2239                         Assert.error();
2240                     }
2241                     currentBindings = matchBindingsComputer.switchCase(label, currentBindings, matchBindings);
2242                 }
2243 
2244                 if (guardBindings != null) {
2245                     currentBindings = matchBindingsComputer.caseGuard(c, currentBindings, guardBindings);
2246                 }
2247 
2248                 Env<AttrContext> caseEnv =
2249                         bindingEnv(switchEnv, c, currentBindings.bindingsWhenTrue);
2250                 try {
2251                     attribCase.accept(c, caseEnv);
2252                 } finally {
2253                     caseEnv.info.scope.leave();
2254                 }
2255                 addVars(c.stats, switchEnv.info.scope);
2256 
2257                 preFlow(c);
2258                 c.completesNormally = flow.aliveAfter(caseEnv, c, make);
2259             }
2260             if (patternSwitch) {
2261                 chk.checkSwitchCaseStructure(cases);
2262                 chk.checkSwitchCaseLabelDominated(unconditionalCaseLabel, cases);
2263             }
2264             if (switchTree.hasTag(SWITCH)) {
2265                 ((JCSwitch) switchTree).hasUnconditionalPattern =
2266                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
2267                 ((JCSwitch) switchTree).patternSwitch = patternSwitch;
2268             } else if (switchTree.hasTag(SWITCH_EXPRESSION)) {
2269                 ((JCSwitchExpression) switchTree).hasUnconditionalPattern =
2270                         hasDefault || hasUnconditionalPattern || lastPatternErroneous;
2271                 ((JCSwitchExpression) switchTree).patternSwitch = patternSwitch;
2272             } else {
2273                 Assert.error(switchTree.getTag().name());
2274             }
2275         } finally {
2276             switchEnv.info.scope.leave();
2277         }
2278     }
2279     // where
2280         private ResultInfo caseLabelResultInfo(Type seltype) {
2281             return new ResultInfo(KindSelector.VAL_TYP,
2282                                   !seltype.hasTag(ERROR) ? seltype
2283                                                          : Type.noType);
2284         }
2285         /** Add any variables defined in stats to the switch scope. */
2286         private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
2287             for (;stats.nonEmpty(); stats = stats.tail) {
2288                 JCTree stat = stats.head;
2289                 if (stat.hasTag(VARDEF))
2290                     switchScope.enter(((JCVariableDecl) stat).sym);
2291             }
2292         }
2293     // where
2294     /** Return the selected enumeration constant symbol, or null. */
2295     private Symbol enumConstant(JCTree tree, Type enumType) {
2296         if (tree.hasTag(IDENT)) {
2297             JCIdent ident = (JCIdent)tree;
2298             Name name = ident.name;
2299             for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
2300                 if (sym.kind == VAR) {
2301                     Symbol s = ident.sym = sym;
2302                     ((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
2303                     ident.type = s.type;
2304                     return ((s.flags_field & Flags.ENUM) == 0)
2305                         ? null : s;
2306                 }
2307             }
2308         }
2309         return null;
2310     }
2311 
2312     public void visitSynchronized(JCSynchronized tree) {
2313         boolean identityType = chk.checkIdentityType(tree.pos(), attribExpr(tree.lock, env));
2314         if (identityType && tree.lock.type != null && tree.lock.type.isValueBased()) {
2315             log.warning(tree.pos(), LintWarnings.AttemptToSynchronizeOnInstanceOfValueBasedClass);
2316         }
2317         attribStat(tree.body, env);
2318         result = null;
2319     }
2320 
2321     public void visitTry(JCTry tree) {
2322         // Create a new local environment with a local
2323         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
2324         try {
2325             boolean isTryWithResource = tree.resources.nonEmpty();
2326             // Create a nested environment for attributing the try block if needed
2327             Env<AttrContext> tryEnv = isTryWithResource ?
2328                 env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
2329                 localEnv;
2330             try {
2331                 // Attribute resource declarations
2332                 for (JCTree resource : tree.resources) {
2333                     CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
2334                         @Override
2335                         public void report(DiagnosticPosition pos, JCDiagnostic details) {
2336                             chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
2337                         }
2338                     };
2339                     ResultInfo twrResult =
2340                         new ResultInfo(KindSelector.VAR,
2341                                        syms.autoCloseableType,
2342                                        twrContext);
2343                     if (resource.hasTag(VARDEF)) {
2344                         attribStat(resource, tryEnv);
2345                         twrResult.check(resource, resource.type);
2346 
2347                         //check that resource type cannot throw InterruptedException
2348                         checkAutoCloseable(resource.pos(), localEnv, resource.type);
2349 
2350                         VarSymbol var = ((JCVariableDecl) resource).sym;
2351 
2352                         var.flags_field |= Flags.FINAL;
2353                         var.setData(ElementKind.RESOURCE_VARIABLE);
2354                     } else {
2355                         attribTree(resource, tryEnv, twrResult);
2356                     }
2357                 }
2358                 // Attribute body
2359                 attribStat(tree.body, tryEnv);
2360             } finally {
2361                 if (isTryWithResource)
2362                     tryEnv.info.scope.leave();
2363             }
2364 
2365             // Attribute catch clauses
2366             for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
2367                 JCCatch c = l.head;
2368                 Env<AttrContext> catchEnv =
2369                     localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
2370                 try {
2371                     Type ctype = attribStat(c.param, catchEnv);
2372                     if (TreeInfo.isMultiCatch(c)) {
2373                         //multi-catch parameter is implicitly marked as final
2374                         c.param.sym.flags_field |= FINAL | UNION;
2375                     }
2376                     if (c.param.sym.kind == VAR) {
2377                         c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
2378                     }
2379                     chk.checkType(c.param.vartype.pos(),
2380                                   chk.checkClassType(c.param.vartype.pos(), ctype),
2381                                   syms.throwableType);
2382                     attribStat(c.body, catchEnv);
2383                 } finally {
2384                     catchEnv.info.scope.leave();
2385                 }
2386             }
2387 
2388             // Attribute finalizer
2389             if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
2390             result = null;
2391         }
2392         finally {
2393             localEnv.info.scope.leave();
2394         }
2395     }
2396 
2397     void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
2398         if (!resource.isErroneous() &&
2399             types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
2400             !types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
2401             Symbol close = syms.noSymbol;
2402             Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
2403             try {
2404                 close = rs.resolveQualifiedMethod(pos,
2405                         env,
2406                         types.skipTypeVars(resource, false),
2407                         names.close,
2408                         List.nil(),
2409                         List.nil());
2410             }
2411             finally {
2412                 log.popDiagnosticHandler(discardHandler);
2413             }
2414             if (close.kind == MTH &&
2415                     close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
2416                     chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes())) {
2417                 log.warning(pos, LintWarnings.TryResourceThrowsInterruptedExc(resource));
2418             }
2419         }
2420     }
2421 
2422     public void visitConditional(JCConditional tree) {
2423         Type condtype = attribExpr(tree.cond, env, syms.booleanType);
2424         MatchBindings condBindings = matchBindings;
2425 
2426         tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
2427                 isBooleanOrNumeric(env, tree)) ?
2428                 PolyKind.STANDALONE : PolyKind.POLY;
2429 
2430         if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
2431             //this means we are returning a poly conditional from void-compatible lambda expression
2432             resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
2433             result = tree.type = types.createErrorType(resultInfo.pt);
2434             return;
2435         }
2436 
2437         ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
2438                 unknownExprInfo :
2439                 resultInfo.dup(conditionalContext(resultInfo.checkContext));
2440 
2441 
2442         // x ? y : z
2443         // include x's bindings when true in y
2444         // include x's bindings when false in z
2445 
2446         Type truetype;
2447         Env<AttrContext> trueEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2448         try {
2449             truetype = attribTree(tree.truepart, trueEnv, condInfo);
2450         } finally {
2451             trueEnv.info.scope.leave();
2452         }
2453 
2454         MatchBindings trueBindings = matchBindings;
2455 
2456         Type falsetype;
2457         Env<AttrContext> falseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2458         try {
2459             falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
2460         } finally {
2461             falseEnv.info.scope.leave();
2462         }
2463 
2464         MatchBindings falseBindings = matchBindings;
2465 
2466         Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
2467                 condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
2468                          List.of(truetype, falsetype)) : pt();
2469         if (condtype.constValue() != null &&
2470                 truetype.constValue() != null &&
2471                 falsetype.constValue() != null &&
2472                 !owntype.hasTag(NONE)) {
2473             //constant folding
2474             owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
2475         }
2476         result = check(tree, owntype, KindSelector.VAL, resultInfo);
2477         matchBindings = matchBindingsComputer.conditional(tree, condBindings, trueBindings, falseBindings);
2478     }
2479     //where
2480         private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
2481             switch (tree.getTag()) {
2482                 case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
2483                               ((JCLiteral)tree).typetag == BOOLEAN ||
2484                               ((JCLiteral)tree).typetag == BOT;
2485                 case LAMBDA: case REFERENCE: return false;
2486                 case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
2487                 case CONDEXPR:
2488                     JCConditional condTree = (JCConditional)tree;
2489                     return isBooleanOrNumeric(env, condTree.truepart) &&
2490                             isBooleanOrNumeric(env, condTree.falsepart);
2491                 case APPLY:
2492                     JCMethodInvocation speculativeMethodTree =
2493                             (JCMethodInvocation)deferredAttr.attribSpeculative(
2494                                     tree, env, unknownExprInfo,
2495                                     argumentAttr.withLocalCacheContext());
2496                     Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
2497                     Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
2498                             env.enclClass.type :
2499                             ((JCFieldAccess)speculativeMethodTree.meth).selected.type;
2500                     Type owntype = types.memberType(receiverType, msym).getReturnType();
2501                     return primitiveOrBoxed(owntype);
2502                 case NEWCLASS:
2503                     JCExpression className =
2504                             removeClassParams.translate(((JCNewClass)tree).clazz);
2505                     JCExpression speculativeNewClassTree =
2506                             (JCExpression)deferredAttr.attribSpeculative(
2507                                     className, env, unknownTypeInfo,
2508                                     argumentAttr.withLocalCacheContext());
2509                     return primitiveOrBoxed(speculativeNewClassTree.type);
2510                 default:
2511                     Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
2512                             argumentAttr.withLocalCacheContext()).type;
2513                     return primitiveOrBoxed(speculativeType);
2514             }
2515         }
2516         //where
2517             boolean primitiveOrBoxed(Type t) {
2518                 return (!t.hasTag(TYPEVAR) && !t.isErroneous() && types.unboxedTypeOrType(t).isPrimitive());
2519             }
2520 
2521             TreeTranslator removeClassParams = new TreeTranslator() {
2522                 @Override
2523                 public void visitTypeApply(JCTypeApply tree) {
2524                     result = translate(tree.clazz);
2525                 }
2526             };
2527 
2528         CheckContext conditionalContext(CheckContext checkContext) {
2529             return new Check.NestedCheckContext(checkContext) {
2530                 //this will use enclosing check context to check compatibility of
2531                 //subexpression against target type; if we are in a method check context,
2532                 //depending on whether boxing is allowed, we could have incompatibilities
2533                 @Override
2534                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
2535                     enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
2536                 }
2537             };
2538         }
2539 
2540         /** Compute the type of a conditional expression, after
2541          *  checking that it exists.  See JLS 15.25. Does not take into
2542          *  account the special case where condition and both arms
2543          *  are constants.
2544          *
2545          *  @param pos      The source position to be used for error
2546          *                  diagnostics.
2547          *  @param thentype The type of the expression's then-part.
2548          *  @param elsetype The type of the expression's else-part.
2549          */
2550         Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
2551             if (condTypes.isEmpty()) {
2552                 return syms.objectType; //TODO: how to handle?
2553             }
2554             Type first = condTypes.head;
2555             // If same type, that is the result
2556             if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
2557                 return first.baseType();
2558 
2559             List<Type> unboxedTypes = condTypes.stream()
2560                                                .map(t -> t.isPrimitive() ? t : types.unboxedType(t))
2561                                                .collect(List.collector());
2562 
2563             // Otherwise, if both arms can be converted to a numeric
2564             // type, return the least numeric type that fits both arms
2565             // (i.e. return larger of the two, or return int if one
2566             // arm is short, the other is char).
2567             if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
2568                 // If one arm has an integer subrange type (i.e., byte,
2569                 // short, or char), and the other is an integer constant
2570                 // that fits into the subrange, return the subrange type.
2571                 for (Type type : unboxedTypes) {
2572                     if (!type.getTag().isStrictSubRangeOf(INT)) {
2573                         continue;
2574                     }
2575                     if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
2576                         return type.baseType();
2577                 }
2578 
2579                 for (TypeTag tag : primitiveTags) {
2580                     Type candidate = syms.typeOfTag[tag.ordinal()];
2581                     if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
2582                         return candidate;
2583                     }
2584                 }
2585             }
2586 
2587             // Those were all the cases that could result in a primitive
2588             condTypes = condTypes.stream()
2589                                  .map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
2590                                  .collect(List.collector());
2591 
2592             for (Type type : condTypes) {
2593                 if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
2594                     return type.baseType();
2595             }
2596 
2597             Iterator<DiagnosticPosition> posIt = positions.iterator();
2598 
2599             condTypes = condTypes.stream()
2600                                  .map(t -> chk.checkNonVoid(posIt.next(), t))
2601                                  .collect(List.collector());
2602 
2603             // both are known to be reference types.  The result is
2604             // lub(thentype,elsetype). This cannot fail, as it will
2605             // always be possible to infer "Object" if nothing better.
2606             return types.lub(condTypes.stream()
2607                         .map(t -> t.baseType())
2608                         .filter(t -> !t.hasTag(BOT))
2609                         .collect(List.collector()));
2610         }
2611 
2612     static final TypeTag[] primitiveTags = new TypeTag[]{
2613         BYTE,
2614         CHAR,
2615         SHORT,
2616         INT,
2617         LONG,
2618         FLOAT,
2619         DOUBLE,
2620         BOOLEAN,
2621     };
2622 
2623     Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
2624         return bindingEnv(env, env.tree, bindings);
2625     }
2626 
2627     Env<AttrContext> bindingEnv(Env<AttrContext> env, JCTree newTree, List<BindingSymbol> bindings) {
2628         Env<AttrContext> env1 = env.dup(newTree, env.info.dup(env.info.scope.dup()));
2629         bindings.forEach(env1.info.scope::enter);
2630         return env1;
2631     }
2632 
2633     public void visitIf(JCIf tree) {
2634         attribExpr(tree.cond, env, syms.booleanType);
2635 
2636         // if (x) { y } [ else z ]
2637         // include x's bindings when true in y
2638         // include x's bindings when false in z
2639 
2640         MatchBindings condBindings = matchBindings;
2641         Env<AttrContext> thenEnv = bindingEnv(env, condBindings.bindingsWhenTrue);
2642 
2643         try {
2644             attribStat(tree.thenpart, thenEnv);
2645         } finally {
2646             thenEnv.info.scope.leave();
2647         }
2648 
2649         preFlow(tree.thenpart);
2650         boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
2651         boolean aliveAfterElse;
2652 
2653         if (tree.elsepart != null) {
2654             Env<AttrContext> elseEnv = bindingEnv(env, condBindings.bindingsWhenFalse);
2655             try {
2656                 attribStat(tree.elsepart, elseEnv);
2657             } finally {
2658                 elseEnv.info.scope.leave();
2659             }
2660             preFlow(tree.elsepart);
2661             aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
2662         } else {
2663             aliveAfterElse = true;
2664         }
2665 
2666         chk.checkEmptyIf(tree);
2667 
2668         List<BindingSymbol> afterIfBindings = List.nil();
2669 
2670         if (aliveAfterThen && !aliveAfterElse) {
2671             afterIfBindings = condBindings.bindingsWhenTrue;
2672         } else if (aliveAfterElse && !aliveAfterThen) {
2673             afterIfBindings = condBindings.bindingsWhenFalse;
2674         }
2675 
2676         addBindings2Scope(tree, afterIfBindings);
2677 
2678         result = null;
2679     }
2680 
2681         void preFlow(JCTree tree) {
2682             attrRecover.doRecovery();
2683             new PostAttrAnalyzer() {
2684                 @Override
2685                 public void scan(JCTree tree) {
2686                     if (tree == null ||
2687                             (tree.type != null &&
2688                             tree.type == Type.stuckType)) {
2689                         //don't touch stuck expressions!
2690                         return;
2691                     }
2692                     super.scan(tree);
2693                 }
2694 
2695                 @Override
2696                 public void visitClassDef(JCClassDecl that) {
2697                     if (that.sym != null) {
2698                         // Method preFlow shouldn't visit class definitions
2699                         // that have not been entered and attributed.
2700                         // See JDK-8254557 and JDK-8203277 for more details.
2701                         super.visitClassDef(that);
2702                     }
2703                 }
2704 
2705                 @Override
2706                 public void visitLambda(JCLambda that) {
2707                     if (that.type != null) {
2708                         // Method preFlow shouldn't visit lambda expressions
2709                         // that have not been entered and attributed.
2710                         // See JDK-8254557 and JDK-8203277 for more details.
2711                         super.visitLambda(that);
2712                     }
2713                 }
2714             }.scan(tree);
2715         }
2716 
2717     public void visitExec(JCExpressionStatement tree) {
2718         //a fresh environment is required for 292 inference to work properly ---
2719         //see Infer.instantiatePolymorphicSignatureInstance()
2720         Env<AttrContext> localEnv = env.dup(tree);
2721         attribExpr(tree.expr, localEnv);
2722         result = null;
2723     }
2724 
2725     public void visitBreak(JCBreak tree) {
2726         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2727         result = null;
2728     }
2729 
2730     public void visitYield(JCYield tree) {
2731         if (env.info.yieldResult != null) {
2732             attribTree(tree.value, env, env.info.yieldResult);
2733             tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
2734         } else {
2735             log.error(tree.pos(), tree.value.hasTag(PARENS)
2736                     ? Errors.NoSwitchExpressionQualify
2737                     : Errors.NoSwitchExpression);
2738             attribTree(tree.value, env, unknownExprInfo);
2739         }
2740         result = null;
2741     }
2742 
2743     public void visitContinue(JCContinue tree) {
2744         tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
2745         result = null;
2746     }
2747     //where
2748         /** Return the target of a break, continue or yield statement,
2749          *  if it exists, report an error if not.
2750          *  Note: The target of a labelled break or continue is the
2751          *  (non-labelled) statement tree referred to by the label,
2752          *  not the tree representing the labelled statement itself.
2753          *
2754          *  @param pos     The position to be used for error diagnostics
2755          *  @param tag     The tag of the jump statement. This is either
2756          *                 Tree.BREAK or Tree.CONTINUE.
2757          *  @param label   The label of the jump statement, or null if no
2758          *                 label is given.
2759          *  @param env     The environment current at the jump statement.
2760          */
2761         private JCTree findJumpTarget(DiagnosticPosition pos,
2762                                                    JCTree.Tag tag,
2763                                                    Name label,
2764                                                    Env<AttrContext> env) {
2765             Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
2766 
2767             if (jumpTarget.snd != null) {
2768                 log.error(pos, jumpTarget.snd);
2769             }
2770 
2771             return jumpTarget.fst;
2772         }
2773         /** Return the target of a break or continue statement, if it exists,
2774          *  report an error if not.
2775          *  Note: The target of a labelled break or continue is the
2776          *  (non-labelled) statement tree referred to by the label,
2777          *  not the tree representing the labelled statement itself.
2778          *
2779          *  @param tag     The tag of the jump statement. This is either
2780          *                 Tree.BREAK or Tree.CONTINUE.
2781          *  @param label   The label of the jump statement, or null if no
2782          *                 label is given.
2783          *  @param env     The environment current at the jump statement.
2784          */
2785         private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
2786                                                                        Name label,
2787                                                                        Env<AttrContext> env) {
2788             // Search environments outwards from the point of jump.
2789             Env<AttrContext> env1 = env;
2790             JCDiagnostic.Error pendingError = null;
2791             LOOP:
2792             while (env1 != null) {
2793                 switch (env1.tree.getTag()) {
2794                     case LABELLED:
2795                         JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
2796                         if (label == labelled.label) {
2797                             // If jump is a continue, check that target is a loop.
2798                             if (tag == CONTINUE) {
2799                                 if (!labelled.body.hasTag(DOLOOP) &&
2800                                         !labelled.body.hasTag(WHILELOOP) &&
2801                                         !labelled.body.hasTag(FORLOOP) &&
2802                                         !labelled.body.hasTag(FOREACHLOOP)) {
2803                                     pendingError = Errors.NotLoopLabel(label);
2804                                 }
2805                                 // Found labelled statement target, now go inwards
2806                                 // to next non-labelled tree.
2807                                 return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
2808                             } else {
2809                                 return Pair.of(labelled, pendingError);
2810                             }
2811                         }
2812                         break;
2813                     case DOLOOP:
2814                     case WHILELOOP:
2815                     case FORLOOP:
2816                     case FOREACHLOOP:
2817                         if (label == null) return Pair.of(env1.tree, pendingError);
2818                         break;
2819                     case SWITCH:
2820                         if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
2821                         break;
2822                     case SWITCH_EXPRESSION:
2823                         if (tag == YIELD) {
2824                             return Pair.of(env1.tree, null);
2825                         } else if (tag == BREAK) {
2826                             pendingError = Errors.BreakOutsideSwitchExpression;
2827                         } else {
2828                             pendingError = Errors.ContinueOutsideSwitchExpression;
2829                         }
2830                         break;
2831                     case LAMBDA:
2832                     case METHODDEF:
2833                     case CLASSDEF:
2834                         break LOOP;
2835                     default:
2836                 }
2837                 env1 = env1.next;
2838             }
2839             if (label != null)
2840                 return Pair.of(null, Errors.UndefLabel(label));
2841             else if (pendingError != null)
2842                 return Pair.of(null, pendingError);
2843             else if (tag == CONTINUE)
2844                 return Pair.of(null, Errors.ContOutsideLoop);
2845             else
2846                 return Pair.of(null, Errors.BreakOutsideSwitchLoop);
2847         }
2848 
2849     public void visitReturn(JCReturn tree) {
2850         // Check that there is an enclosing method which is
2851         // nested within than the enclosing class.
2852         if (env.info.returnResult == null) {
2853             log.error(tree.pos(), Errors.RetOutsideMeth);
2854         } else if (env.info.yieldResult != null) {
2855             log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
2856             if (tree.expr != null) {
2857                 attribExpr(tree.expr, env, env.info.yieldResult.pt);
2858             }
2859         } else if (!env.info.isLambda &&
2860                 env.enclMethod != null &&
2861                 TreeInfo.isCompactConstructor(env.enclMethod)) {
2862             log.error(env.enclMethod,
2863                     Errors.InvalidCanonicalConstructorInRecord(Fragments.Compact, env.enclMethod.sym.name, Fragments.CanonicalCantHaveReturnStatement));
2864         } else {
2865             // Attribute return expression, if it exists, and check that
2866             // it conforms to result type of enclosing method.
2867             if (tree.expr != null) {
2868                 if (env.info.returnResult.pt.hasTag(VOID)) {
2869                     env.info.returnResult.checkContext.report(tree.expr.pos(),
2870                               diags.fragment(Fragments.UnexpectedRetVal));
2871                 }
2872                 attribTree(tree.expr, env, env.info.returnResult);
2873             } else if (!env.info.returnResult.pt.hasTag(VOID) &&
2874                     !env.info.returnResult.pt.hasTag(NONE)) {
2875                 env.info.returnResult.checkContext.report(tree.pos(),
2876                               diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
2877             }
2878         }
2879         result = null;
2880     }
2881 
2882     public void visitThrow(JCThrow tree) {
2883         Type owntype = attribExpr(tree.expr, env, Type.noType);
2884         chk.checkType(tree, owntype, syms.throwableType);
2885         result = null;
2886     }
2887 
2888     public void visitAssert(JCAssert tree) {
2889         attribExpr(tree.cond, env, syms.booleanType);
2890         if (tree.detail != null) {
2891             chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
2892         }
2893         result = null;
2894     }
2895 
2896      /** Visitor method for method invocations.
2897      *  NOTE: The method part of an application will have in its type field
2898      *        the return type of the method, not the method's type itself!
2899      */
2900     public void visitApply(JCMethodInvocation tree) {
2901         // The local environment of a method application is
2902         // a new environment nested in the current one.
2903         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
2904 
2905         // The types of the actual method arguments.
2906         List<Type> argtypes;
2907 
2908         // The types of the actual method type arguments.
2909         List<Type> typeargtypes = null;
2910 
2911         Name methName = TreeInfo.name(tree.meth);
2912 
2913         boolean isConstructorCall =
2914             methName == names._this || methName == names._super;
2915 
2916         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
2917         if (isConstructorCall) {
2918 
2919             // Attribute arguments, yielding list of argument types.
2920             KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
2921             argtypes = argtypesBuf.toList();
2922             typeargtypes = attribTypes(tree.typeargs, localEnv);
2923 
2924             // Done with this()/super() parameters. End of constructor prologue.
2925             env.info.ctorPrologue = false;
2926 
2927             // Variable `site' points to the class in which the called
2928             // constructor is defined.
2929             Type site = env.enclClass.sym.type;
2930             if (methName == names._super) {
2931                 if (site == syms.objectType) {
2932                     log.error(tree.meth.pos(), Errors.NoSuperclass(site));
2933                     site = types.createErrorType(syms.objectType);
2934                 } else {
2935                     site = types.supertype(site);
2936                 }
2937             }
2938 
2939             if (site.hasTag(CLASS)) {
2940                 Type encl = site.getEnclosingType();
2941                 while (encl != null && encl.hasTag(TYPEVAR))
2942                     encl = encl.getUpperBound();
2943                 if (encl.hasTag(CLASS)) {
2944                     // we are calling a nested class
2945 
2946                     if (tree.meth.hasTag(SELECT)) {
2947                         JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
2948 
2949                         // We are seeing a prefixed call, of the form
2950                         //     <expr>.super(...).
2951                         // Check that the prefix expression conforms
2952                         // to the outer instance type of the class.
2953                         chk.checkRefType(qualifier.pos(),
2954                                          attribExpr(qualifier, localEnv,
2955                                                     encl));
2956                     }
2957                 } else if (tree.meth.hasTag(SELECT)) {
2958                     log.error(tree.meth.pos(),
2959                               Errors.IllegalQualNotIcls(site.tsym));
2960                     attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2961                 }
2962 
2963                 if (tree.meth.hasTag(IDENT)) {
2964                     // non-qualified super(...) call; check whether explicit constructor
2965                     // invocation is well-formed. If the super class is an inner class,
2966                     // make sure that an appropriate implicit qualifier exists. If the super
2967                     // class is a local class, make sure that the current class is defined
2968                     // in the same context as the local class.
2969                     checkNewInnerClass(tree.meth.pos(), localEnv, site, true);
2970                 }
2971 
2972                 // if we're calling a java.lang.Enum constructor,
2973                 // prefix the implicit String and int parameters
2974                 if (site.tsym == syms.enumSym)
2975                     argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
2976 
2977                 // Resolve the called constructor under the assumption
2978                 // that we are referring to a superclass instance of the
2979                 // current instance (JLS ???).
2980                 boolean selectSuperPrev = localEnv.info.selectSuper;
2981                 localEnv.info.selectSuper = true;
2982                 localEnv.info.pendingResolutionPhase = null;
2983                 Symbol sym = rs.resolveConstructor(
2984                     tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
2985                 localEnv.info.selectSuper = selectSuperPrev;
2986 
2987                 // Set method symbol to resolved constructor...
2988                 TreeInfo.setSymbol(tree.meth, sym);
2989 
2990                 // ...and check that it is legal in the current context.
2991                 // (this will also set the tree's type)
2992                 Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
2993                 checkId(tree.meth, site, sym, localEnv,
2994                         new ResultInfo(kind, mpt));
2995             } else if (site.hasTag(ERROR) && tree.meth.hasTag(SELECT)) {
2996                 attribExpr(((JCFieldAccess) tree.meth).selected, localEnv, site);
2997             }
2998             // Otherwise, `site' is an error type and we do nothing
2999             result = tree.type = syms.voidType;
3000         } else {
3001             // Otherwise, we are seeing a regular method call.
3002             // Attribute the arguments, yielding list of argument types, ...
3003             KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
3004             argtypes = argtypesBuf.toList();
3005             typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
3006 
3007             // ... and attribute the method using as a prototype a methodtype
3008             // whose formal argument types is exactly the list of actual
3009             // arguments (this will also set the method symbol).
3010             Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
3011             localEnv.info.pendingResolutionPhase = null;
3012             Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
3013 
3014             // Compute the result type.
3015             Type restype = mtype.getReturnType();
3016             if (restype.hasTag(WILDCARD))
3017                 throw new AssertionError(mtype);
3018 
3019             Type qualifier = (tree.meth.hasTag(SELECT))
3020                     ? ((JCFieldAccess) tree.meth).selected.type
3021                     : env.enclClass.sym.type;
3022             Symbol msym = TreeInfo.symbol(tree.meth);
3023             restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
3024 
3025             chk.checkRefTypes(tree.typeargs, typeargtypes);
3026 
3027             // Check that value of resulting type is admissible in the
3028             // current context.  Also, capture the return type
3029             Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
3030             result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
3031         }
3032         chk.checkRequiresIdentity(tree, env.info.lint);
3033         chk.validate(tree.typeargs, localEnv);
3034     }
3035     //where
3036         Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
3037             if (msym != null &&
3038                     (msym.owner == syms.objectType.tsym || msym.owner.isInterface()) &&
3039                     methodName == names.getClass &&
3040                     argtypes.isEmpty()) {
3041                 // as a special case, x.getClass() has type Class<? extends |X|>
3042                 return new ClassType(restype.getEnclosingType(),
3043                         List.of(new WildcardType(types.erasure(qualifierType.baseType()),
3044                                 BoundKind.EXTENDS,
3045                                 syms.boundClass)),
3046                         restype.tsym,
3047                         restype.getMetadata());
3048             } else if (msym != null &&
3049                     msym.owner == syms.arrayClass &&
3050                     methodName == names.clone &&
3051                     types.isArray(qualifierType)) {
3052                 // as a special case, array.clone() has a result that is
3053                 // the same as static type of the array being cloned
3054                 return qualifierType;
3055             } else {
3056                 return restype;
3057             }
3058         }
3059 
3060         /** Obtain a method type with given argument types.
3061          */
3062         Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
3063             MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
3064             return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
3065         }
3066 
3067     public void visitNewClass(final JCNewClass tree) {
3068         Type owntype = types.createErrorType(tree.type);
3069 
3070         // The local environment of a class creation is
3071         // a new environment nested in the current one.
3072         Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
3073 
3074         // The anonymous inner class definition of the new expression,
3075         // if one is defined by it.
3076         JCClassDecl cdef = tree.def;
3077 
3078         // If enclosing class is given, attribute it, and
3079         // complete class name to be fully qualified
3080         JCExpression clazz = tree.clazz; // Class field following new
3081         JCExpression clazzid;            // Identifier in class field
3082         JCAnnotatedType annoclazzid;     // Annotated type enclosing clazzid
3083         annoclazzid = null;
3084 
3085         if (clazz.hasTag(TYPEAPPLY)) {
3086             clazzid = ((JCTypeApply) clazz).clazz;
3087             if (clazzid.hasTag(ANNOTATED_TYPE)) {
3088                 annoclazzid = (JCAnnotatedType) clazzid;
3089                 clazzid = annoclazzid.underlyingType;
3090             }
3091         } else {
3092             if (clazz.hasTag(ANNOTATED_TYPE)) {
3093                 annoclazzid = (JCAnnotatedType) clazz;
3094                 clazzid = annoclazzid.underlyingType;
3095             } else {
3096                 clazzid = clazz;
3097             }
3098         }
3099 
3100         JCExpression clazzid1 = clazzid; // The same in fully qualified form
3101 
3102         if (tree.encl != null) {
3103             // We are seeing a qualified new, of the form
3104             //    <expr>.new C <...> (...) ...
3105             // In this case, we let clazz stand for the name of the
3106             // allocated class C prefixed with the type of the qualifier
3107             // expression, so that we can
3108             // resolve it with standard techniques later. I.e., if
3109             // <expr> has type T, then <expr>.new C <...> (...)
3110             // yields a clazz T.C.
3111             Type encltype = chk.checkRefType(tree.encl.pos(),
3112                                              attribExpr(tree.encl, env));
3113             // TODO 308: in <expr>.new C, do we also want to add the type annotations
3114             // from expr to the combined type, or not? Yes, do this.
3115             clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
3116                                                  ((JCIdent) clazzid).name);
3117 
3118             EndPosTable endPosTable = this.env.toplevel.endPositions;
3119             endPosTable.storeEnd(clazzid1, clazzid.getEndPosition(endPosTable));
3120             if (clazz.hasTag(ANNOTATED_TYPE)) {
3121                 JCAnnotatedType annoType = (JCAnnotatedType) clazz;
3122                 List<JCAnnotation> annos = annoType.annotations;
3123 
3124                 if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
3125                     clazzid1 = make.at(tree.pos).
3126                         TypeApply(clazzid1,
3127                                   ((JCTypeApply) clazz).arguments);
3128                 }
3129 
3130                 clazzid1 = make.at(tree.pos).
3131                     AnnotatedType(annos, clazzid1);
3132             } else if (clazz.hasTag(TYPEAPPLY)) {
3133                 clazzid1 = make.at(tree.pos).
3134                     TypeApply(clazzid1,
3135                               ((JCTypeApply) clazz).arguments);
3136             }
3137 
3138             clazz = clazzid1;
3139         }
3140 
3141         // Attribute clazz expression and store
3142         // symbol + type back into the attributed tree.
3143         Type clazztype;
3144 
3145         try {
3146             env.info.isAnonymousNewClass = tree.def != null;
3147             clazztype = TreeInfo.isEnumInit(env.tree) ?
3148                 attribIdentAsEnumType(env, (JCIdent)clazz) :
3149                 attribType(clazz, env);
3150         } finally {
3151             env.info.isAnonymousNewClass = false;
3152         }
3153 
3154         clazztype = chk.checkDiamond(tree, clazztype);
3155         chk.validate(clazz, localEnv);
3156         if (tree.encl != null) {
3157             // We have to work in this case to store
3158             // symbol + type back into the attributed tree.
3159             tree.clazz.type = clazztype;
3160             TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
3161             clazzid.type = ((JCIdent) clazzid).sym.type;
3162             if (annoclazzid != null) {
3163                 annoclazzid.type = clazzid.type;
3164             }
3165             if (!clazztype.isErroneous()) {
3166                 if (cdef != null && clazztype.tsym.isInterface()) {
3167                     log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
3168                 } else if (clazztype.tsym.isStatic()) {
3169                     log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
3170                 }
3171             }
3172         } else {
3173             // Check for the existence of an apropos outer instance
3174             checkNewInnerClass(tree.pos(), env, clazztype, false);
3175         }
3176 
3177         // Attribute constructor arguments.
3178         ListBuffer<Type> argtypesBuf = new ListBuffer<>();
3179         final KindSelector pkind =
3180             attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
3181         List<Type> argtypes = argtypesBuf.toList();
3182         List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
3183 
3184         if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
3185             // Enums may not be instantiated except implicitly
3186             if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
3187                 (!env.tree.hasTag(VARDEF) ||
3188                  (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
3189                  ((JCVariableDecl) env.tree).init != tree))
3190                 log.error(tree.pos(), Errors.EnumCantBeInstantiated);
3191 
3192             boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
3193                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3194             boolean skipNonDiamondPath = false;
3195             // Check that class is not abstract
3196             if (cdef == null && !tree.classDeclRemoved() && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
3197                 (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
3198                 log.error(tree.pos(),
3199                           Errors.AbstractCantBeInstantiated(clazztype.tsym));
3200                 skipNonDiamondPath = true;
3201             } else if (cdef != null && clazztype.tsym.isInterface()) {
3202                 // Check that no constructor arguments are given to
3203                 // anonymous classes implementing an interface
3204                 if (!argtypes.isEmpty())
3205                     log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
3206 
3207                 if (!typeargtypes.isEmpty())
3208                     log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
3209 
3210                 // Error recovery: pretend no arguments were supplied.
3211                 argtypes = List.nil();
3212                 typeargtypes = List.nil();
3213                 skipNonDiamondPath = true;
3214             }
3215             if (TreeInfo.isDiamond(tree)) {
3216                 ClassType site = new ClassType(clazztype.getEnclosingType(),
3217                             clazztype.tsym.type.getTypeArguments(),
3218                                                clazztype.tsym,
3219                                                clazztype.getMetadata());
3220 
3221                 Env<AttrContext> diamondEnv = localEnv.dup(tree);
3222                 diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
3223                 diamondEnv.info.pendingResolutionPhase = null;
3224 
3225                 //if the type of the instance creation expression is a class type
3226                 //apply method resolution inference (JLS 15.12.2.7). The return type
3227                 //of the resolved constructor will be a partially instantiated type
3228                 Symbol constructor = rs.resolveDiamond(tree.pos(),
3229                             diamondEnv,
3230                             site,
3231                             argtypes,
3232                             typeargtypes);
3233                 tree.constructor = constructor.baseSymbol();
3234 
3235                 final TypeSymbol csym = clazztype.tsym;
3236                 ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
3237                         diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
3238                 Type constructorType = tree.constructorType = types.createErrorType(clazztype);
3239                 constructorType = checkId(tree, site,
3240                         constructor,
3241                         diamondEnv,
3242                         diamondResult);
3243 
3244                 tree.clazz.type = types.createErrorType(clazztype);
3245                 if (!constructorType.isErroneous()) {
3246                     tree.clazz.type = clazz.type = constructorType.getReturnType();
3247                     tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
3248                 }
3249                 clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
3250             }
3251 
3252             // Resolve the called constructor under the assumption
3253             // that we are referring to a superclass instance of the
3254             // current instance (JLS ???).
3255             else if (!skipNonDiamondPath) {
3256                 //the following code alters some of the fields in the current
3257                 //AttrContext - hence, the current context must be dup'ed in
3258                 //order to avoid downstream failures
3259                 Env<AttrContext> rsEnv = localEnv.dup(tree);
3260                 rsEnv.info.selectSuper = cdef != null;
3261                 rsEnv.info.pendingResolutionPhase = null;
3262                 tree.constructor = rs.resolveConstructor(
3263                     tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
3264                 if (cdef == null) { //do not check twice!
3265                     tree.constructorType = checkId(tree,
3266                             clazztype,
3267                             tree.constructor,
3268                             rsEnv,
3269                             new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3270                     if (rsEnv.info.lastResolveVarargs())
3271                         Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
3272                 }
3273             }
3274 
3275             chk.checkRequiresIdentity(tree, env.info.lint);
3276 
3277             if (cdef != null) {
3278                 visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
3279                 return;
3280             }
3281 
3282             if (tree.constructor != null && tree.constructor.kind == MTH)
3283                 owntype = clazztype;
3284         }
3285         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3286         InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
3287         if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
3288             //we need to wait for inference to finish and then replace inference vars in the constructor type
3289             inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
3290                     instantiatedContext -> {
3291                         tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
3292                     });
3293         }
3294         chk.validate(tree.typeargs, localEnv);
3295     }
3296 
3297         // where
3298         private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
3299                                                    JCClassDecl cdef, Env<AttrContext> localEnv,
3300                                                    List<Type> argtypes, List<Type> typeargtypes,
3301                                                    KindSelector pkind) {
3302             // We are seeing an anonymous class instance creation.
3303             // In this case, the class instance creation
3304             // expression
3305             //
3306             //    E.new <typeargs1>C<typargs2>(args) { ... }
3307             //
3308             // is represented internally as
3309             //
3310             //    E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } )  .
3311             //
3312             // This expression is then *transformed* as follows:
3313             //
3314             // (1) add an extends or implements clause
3315             // (2) add a constructor.
3316             //
3317             // For instance, if C is a class, and ET is the type of E,
3318             // the expression
3319             //
3320             //    E.new <typeargs1>C<typargs2>(args) { ... }
3321             //
3322             // is translated to (where X is a fresh name and typarams is the
3323             // parameter list of the super constructor):
3324             //
3325             //   new <typeargs1>X(<*nullchk*>E, args) where
3326             //     X extends C<typargs2> {
3327             //       <typarams> X(ET e, args) {
3328             //         e.<typeargs1>super(args)
3329             //       }
3330             //       ...
3331             //     }
3332             InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
3333             Type enclType = clazztype.getEnclosingType();
3334             if (enclType != null &&
3335                     enclType.hasTag(CLASS) &&
3336                     !chk.checkDenotable((ClassType)enclType)) {
3337                 log.error(tree.encl, Errors.EnclosingClassTypeNonDenotable(enclType));
3338             }
3339             final boolean isDiamond = TreeInfo.isDiamond(tree);
3340             if (isDiamond
3341                     && ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
3342                     || (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
3343                 final ResultInfo resultInfoForClassDefinition = this.resultInfo;
3344                 Env<AttrContext> dupLocalEnv = copyEnv(localEnv);
3345                 inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
3346                         instantiatedContext -> {
3347                             tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
3348                             tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
3349                             ResultInfo prevResult = this.resultInfo;
3350                             try {
3351                                 this.resultInfo = resultInfoForClassDefinition;
3352                                 visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
3353                                         dupLocalEnv, argtypes, typeargtypes, pkind);
3354                             } finally {
3355                                 this.resultInfo = prevResult;
3356                             }
3357                         });
3358             } else {
3359                 if (isDiamond && clazztype.hasTag(CLASS)) {
3360                     List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
3361                     if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
3362                         // One or more types inferred in the previous steps is non-denotable.
3363                         Fragment fragment = Diamond(clazztype.tsym);
3364                         log.error(tree.clazz.pos(),
3365                                 Errors.CantApplyDiamond1(
3366                                         fragment,
3367                                         invalidDiamondArgs.size() > 1 ?
3368                                                 DiamondInvalidArgs(invalidDiamondArgs, fragment) :
3369                                                 DiamondInvalidArg(invalidDiamondArgs, fragment)));
3370                     }
3371                     // For <>(){}, inferred types must also be accessible.
3372                     for (Type t : clazztype.getTypeArguments()) {
3373                         rs.checkAccessibleType(env, t);
3374                     }
3375                 }
3376 
3377                 // If we already errored, be careful to avoid a further avalanche. ErrorType answers
3378                 // false for isInterface call even when the original type is an interface.
3379                 boolean implementing = clazztype.tsym.isInterface() ||
3380                         clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
3381                         clazztype.getOriginalType().tsym.isInterface();
3382 
3383                 if (implementing) {
3384                     cdef.implementing = List.of(clazz);
3385                 } else {
3386                     cdef.extending = clazz;
3387                 }
3388 
3389                 if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
3390                     rs.isSerializable(clazztype)) {
3391                     localEnv.info.isSerializable = true;
3392                 }
3393 
3394                 attribStat(cdef, localEnv);
3395 
3396                 List<Type> finalargtypes;
3397                 // If an outer instance is given,
3398                 // prefix it to the constructor arguments
3399                 // and delete it from the new expression
3400                 if (tree.encl != null && !clazztype.tsym.isInterface()) {
3401                     finalargtypes = argtypes.prepend(tree.encl.type);
3402                 } else {
3403                     finalargtypes = argtypes;
3404                 }
3405 
3406                 // Reassign clazztype and recompute constructor. As this necessarily involves
3407                 // another attribution pass for deferred types in the case of <>, replicate
3408                 // them. Original arguments have right decorations already.
3409                 if (isDiamond && pkind.contains(KindSelector.POLY)) {
3410                     finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
3411                 }
3412 
3413                 clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
3414                                                     : cdef.sym.type;
3415                 Symbol sym = tree.constructor = rs.resolveConstructor(
3416                         tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
3417                 Assert.check(!sym.kind.isResolutionError());
3418                 tree.constructor = sym;
3419                 tree.constructorType = checkId(tree,
3420                         clazztype,
3421                         tree.constructor,
3422                         localEnv,
3423                         new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
3424             }
3425             Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
3426                                 clazztype : types.createErrorType(tree.type);
3427             result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
3428             chk.validate(tree.typeargs, localEnv);
3429         }
3430 
3431         CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
3432             return new Check.NestedCheckContext(checkContext) {
3433                 @Override
3434                 public void report(DiagnosticPosition _unused, JCDiagnostic details) {
3435                     enclosingContext.report(clazz.clazz,
3436                             diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
3437                 }
3438             };
3439         }
3440 
3441         void checkNewInnerClass(DiagnosticPosition pos, Env<AttrContext> env, Type type, boolean isSuper) {
3442             boolean isLocal = type.tsym.owner.kind == VAR || type.tsym.owner.kind == MTH;
3443             if ((type.tsym.flags() & (INTERFACE | ENUM | RECORD)) != 0 ||
3444                     (!isLocal && !type.tsym.isInner()) ||
3445                     (isSuper && env.enclClass.sym.isAnonymous())) {
3446                 // nothing to check
3447                 return;
3448             }
3449             Symbol res = isLocal ?
3450                     rs.findLocalClassOwner(env, type.tsym) :
3451                     rs.findSelfContaining(pos, env, type.getEnclosingType().tsym, isSuper);
3452             if (res.exists()) {
3453                 rs.accessBase(res, pos, env.enclClass.sym.type, names._this, true);
3454             } else {
3455                 log.error(pos, Errors.EnclClassRequired(type.tsym));
3456             }
3457         }
3458 
3459     /** Make an attributed null check tree.
3460      */
3461     public JCExpression makeNullCheck(JCExpression arg) {
3462         // optimization: new Outer() can never be null; skip null check
3463         if (arg.getTag() == NEWCLASS)
3464             return arg;
3465         // optimization: X.this is never null; skip null check
3466         Name name = TreeInfo.name(arg);
3467         if (name == names._this || name == names._super) return arg;
3468 
3469         JCTree.Tag optag = NULLCHK;
3470         JCUnary tree = make.at(arg.pos).Unary(optag, arg);
3471         tree.operator = operators.resolveUnary(arg, optag, arg.type);
3472         tree.type = arg.type;
3473         return tree;
3474     }
3475 
3476     public void visitNewArray(JCNewArray tree) {
3477         Type owntype = types.createErrorType(tree.type);
3478         Env<AttrContext> localEnv = env.dup(tree);
3479         Type elemtype;
3480         if (tree.elemtype != null) {
3481             elemtype = attribType(tree.elemtype, localEnv);
3482             chk.validate(tree.elemtype, localEnv);
3483             owntype = elemtype;
3484             for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
3485                 attribExpr(l.head, localEnv, syms.intType);
3486                 owntype = new ArrayType(owntype, syms.arrayClass);
3487             }
3488         } else {
3489             // we are seeing an untyped aggregate { ... }
3490             // this is allowed only if the prototype is an array
3491             if (pt().hasTag(ARRAY)) {
3492                 elemtype = types.elemtype(pt());
3493             } else {
3494                 if (!pt().hasTag(ERROR) &&
3495                         (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3496                     log.error(tree.pos(),
3497                               Errors.IllegalInitializerForType(pt()));
3498                 }
3499                 elemtype = types.createErrorType(pt());
3500             }
3501         }
3502         if (tree.elems != null) {
3503             attribExprs(tree.elems, localEnv, elemtype);
3504             owntype = new ArrayType(elemtype, syms.arrayClass);
3505         }
3506         if (!types.isReifiable(elemtype))
3507             log.error(tree.pos(), Errors.GenericArrayCreation);
3508         result = check(tree, owntype, KindSelector.VAL, resultInfo);
3509     }
3510 
3511     /*
3512      * A lambda expression can only be attributed when a target-type is available.
3513      * In addition, if the target-type is that of a functional interface whose
3514      * descriptor contains inference variables in argument position the lambda expression
3515      * is 'stuck' (see DeferredAttr).
3516      */
3517     @Override
3518     public void visitLambda(final JCLambda that) {
3519         boolean wrongContext = false;
3520         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3521             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3522                 //lambda only allowed in assignment or method invocation/cast context
3523                 log.error(that.pos(), Errors.UnexpectedLambda);
3524             }
3525             resultInfo = recoveryInfo;
3526             wrongContext = true;
3527         }
3528         //create an environment for attribution of the lambda expression
3529         final Env<AttrContext> localEnv = lambdaEnv(that, env);
3530         boolean needsRecovery =
3531                 resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
3532         try {
3533             if (needsRecovery && rs.isSerializable(pt())) {
3534                 localEnv.info.isSerializable = true;
3535                 localEnv.info.isSerializableLambda = true;
3536             }
3537             List<Type> explicitParamTypes = null;
3538             if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
3539                 //attribute lambda parameters
3540                 attribStats(that.params, localEnv);
3541                 explicitParamTypes = TreeInfo.types(that.params);
3542             }
3543 
3544             TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
3545             Type currentTarget = targetInfo.target;
3546             Type lambdaType = targetInfo.descriptor;
3547 
3548             if (currentTarget.isErroneous()) {
3549                 result = that.type = currentTarget;
3550                 return;
3551             }
3552 
3553             setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
3554 
3555             if (lambdaType.hasTag(FORALL)) {
3556                 //lambda expression target desc cannot be a generic method
3557                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3558                                                                     kindName(currentTarget.tsym),
3559                                                                     currentTarget.tsym);
3560                 resultInfo.checkContext.report(that, diags.fragment(msg));
3561                 result = that.type = types.createErrorType(pt());
3562                 return;
3563             }
3564 
3565             if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
3566                 //add param type info in the AST
3567                 List<Type> actuals = lambdaType.getParameterTypes();
3568                 List<JCVariableDecl> params = that.params;
3569 
3570                 boolean arityMismatch = false;
3571 
3572                 while (params.nonEmpty()) {
3573                     if (actuals.isEmpty()) {
3574                         //not enough actuals to perform lambda parameter inference
3575                         arityMismatch = true;
3576                     }
3577                     //reset previously set info
3578                     Type argType = arityMismatch ?
3579                             syms.errType :
3580                             actuals.head;
3581                     if (params.head.isImplicitlyTyped()) {
3582                         setSyntheticVariableType(params.head, argType);
3583                     }
3584                     params.head.sym = null;
3585                     actuals = actuals.isEmpty() ?
3586                             actuals :
3587                             actuals.tail;
3588                     params = params.tail;
3589                 }
3590 
3591                 //attribute lambda parameters
3592                 attribStats(that.params, localEnv);
3593 
3594                 if (arityMismatch) {
3595                     resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3596                         result = that.type = types.createErrorType(currentTarget);
3597                         return;
3598                 }
3599             }
3600 
3601             //from this point on, no recovery is needed; if we are in assignment context
3602             //we will be able to attribute the whole lambda body, regardless of errors;
3603             //if we are in a 'check' method context, and the lambda is not compatible
3604             //with the target-type, it will be recovered anyway in Attr.checkId
3605             needsRecovery = false;
3606 
3607             ResultInfo bodyResultInfo = localEnv.info.returnResult =
3608                     lambdaBodyResult(that, lambdaType, resultInfo);
3609 
3610             if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
3611                 attribTree(that.getBody(), localEnv, bodyResultInfo);
3612             } else {
3613                 JCBlock body = (JCBlock)that.body;
3614                 if (body == breakTree &&
3615                         resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
3616                     breakTreeFound(copyEnv(localEnv));
3617                 }
3618                 attribStats(body.stats, localEnv);
3619             }
3620 
3621             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
3622 
3623             boolean isSpeculativeRound =
3624                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
3625 
3626             preFlow(that);
3627             flow.analyzeLambda(env, that, make, isSpeculativeRound);
3628 
3629             that.type = currentTarget; //avoids recovery at this stage
3630             checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
3631 
3632             if (!isSpeculativeRound) {
3633                 //add thrown types as bounds to the thrown types free variables if needed:
3634                 if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
3635                     List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
3636                     if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
3637                         log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
3638                     }
3639                 }
3640 
3641                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
3642             }
3643             result = wrongContext ? that.type = types.createErrorType(pt())
3644                                   : check(that, currentTarget, KindSelector.VAL, resultInfo);
3645         } catch (Types.FunctionDescriptorLookupError ex) {
3646             JCDiagnostic cause = ex.getDiagnostic();
3647             resultInfo.checkContext.report(that, cause);
3648             result = that.type = types.createErrorType(pt());
3649             return;
3650         } catch (CompletionFailure cf) {
3651             chk.completionError(that.pos(), cf);
3652         } catch (Throwable t) {
3653             //when an unexpected exception happens, avoid attempts to attribute the same tree again
3654             //as that would likely cause the same exception again.
3655             needsRecovery = false;
3656             throw t;
3657         } finally {
3658             localEnv.info.scope.leave();
3659             if (needsRecovery) {
3660                 Type prevResult = result;
3661                 try {
3662                     attribTree(that, env, recoveryInfo);
3663                 } finally {
3664                     if (result == Type.recoveryType) {
3665                         result = prevResult;
3666                     }
3667                 }
3668             }
3669         }
3670     }
3671     //where
3672         class TargetInfo {
3673             Type target;
3674             Type descriptor;
3675 
3676             public TargetInfo(Type target, Type descriptor) {
3677                 this.target = target;
3678                 this.descriptor = descriptor;
3679             }
3680         }
3681 
3682         TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
3683             Type lambdaType;
3684             Type currentTarget = resultInfo.pt;
3685             if (resultInfo.pt != Type.recoveryType) {
3686                 /* We need to adjust the target. If the target is an
3687                  * intersection type, for example: SAM & I1 & I2 ...
3688                  * the target will be updated to SAM
3689                  */
3690                 currentTarget = targetChecker.visit(currentTarget, that);
3691                 if (!currentTarget.isIntersection()) {
3692                     if (explicitParamTypes != null) {
3693                         currentTarget = infer.instantiateFunctionalInterface(that,
3694                                 currentTarget, explicitParamTypes, resultInfo.checkContext);
3695                     }
3696                     currentTarget = types.removeWildcards(currentTarget);
3697                     lambdaType = types.findDescriptorType(currentTarget);
3698                 } else {
3699                     IntersectionClassType ict = (IntersectionClassType)currentTarget;
3700                     ListBuffer<Type> components = new ListBuffer<>();
3701                     for (Type bound : ict.getExplicitComponents()) {
3702                         if (explicitParamTypes != null) {
3703                             try {
3704                                 bound = infer.instantiateFunctionalInterface(that,
3705                                         bound, explicitParamTypes, resultInfo.checkContext);
3706                             } catch (FunctionDescriptorLookupError t) {
3707                                 // do nothing
3708                             }
3709                         }
3710                         if (bound.tsym != syms.objectType.tsym && (!bound.isInterface() || (bound.tsym.flags() & ANNOTATION) != 0)) {
3711                             // bound must be j.l.Object or an interface, but not an annotation
3712                             reportIntersectionError(that, "not.an.intf.component", bound);
3713                         }
3714                         bound = types.removeWildcards(bound);
3715                         components.add(bound);
3716                     }
3717                     currentTarget = types.makeIntersectionType(components.toList());
3718                     currentTarget.tsym.flags_field |= INTERFACE;
3719                     lambdaType = types.findDescriptorType(currentTarget);
3720                 }
3721 
3722             } else {
3723                 currentTarget = Type.recoveryType;
3724                 lambdaType = fallbackDescriptorType(that);
3725             }
3726             if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
3727                 //lambda expression target desc cannot be a generic method
3728                 Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
3729                                                                     kindName(currentTarget.tsym),
3730                                                                     currentTarget.tsym);
3731                 resultInfo.checkContext.report(that, diags.fragment(msg));
3732                 currentTarget = types.createErrorType(pt());
3733             }
3734             return new TargetInfo(currentTarget, lambdaType);
3735         }
3736 
3737         private void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) {
3738              resultInfo.checkContext.report(pos,
3739                  diags.fragment(Fragments.BadIntersectionTargetForFunctionalExpr(diags.fragment(key, args))));
3740         }
3741 
3742         void preFlow(JCLambda tree) {
3743             attrRecover.doRecovery();
3744             new PostAttrAnalyzer() {
3745                 @Override
3746                 public void scan(JCTree tree) {
3747                     if (tree == null ||
3748                             (tree.type != null &&
3749                             tree.type == Type.stuckType)) {
3750                         //don't touch stuck expressions!
3751                         return;
3752                     }
3753                     super.scan(tree);
3754                 }
3755 
3756                 @Override
3757                 public void visitClassDef(JCClassDecl that) {
3758                     // or class declaration trees!
3759                 }
3760 
3761                 public void visitLambda(JCLambda that) {
3762                     // or lambda expressions!
3763                 }
3764             }.scan(tree.body);
3765         }
3766 
3767         Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
3768 
3769             @Override
3770             public Type visitClassType(ClassType t, DiagnosticPosition pos) {
3771                 return t.isIntersection() ?
3772                         visitIntersectionClassType((IntersectionClassType)t, pos) : t;
3773             }
3774 
3775             public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
3776                 types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
3777                 return ict;
3778             }
3779 
3780             private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
3781                 ListBuffer<Type> targs = new ListBuffer<>();
3782                 ListBuffer<Type> supertypes = new ListBuffer<>();
3783                 for (Type i : ict.interfaces_field) {
3784                     if (i.isParameterized()) {
3785                         targs.appendList(i.tsym.type.allparams());
3786                     }
3787                     supertypes.append(i.tsym.type);
3788                 }
3789                 IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
3790                 notionalIntf.allparams_field = targs.toList();
3791                 notionalIntf.tsym.flags_field |= INTERFACE;
3792                 return notionalIntf.tsym;
3793             }
3794         };
3795 
3796         private Type fallbackDescriptorType(JCExpression tree) {
3797             switch (tree.getTag()) {
3798                 case LAMBDA:
3799                     JCLambda lambda = (JCLambda)tree;
3800                     List<Type> argtypes = List.nil();
3801                     for (JCVariableDecl param : lambda.params) {
3802                         argtypes = param.vartype != null && param.vartype.type != null ?
3803                                 argtypes.append(param.vartype.type) :
3804                                 argtypes.append(syms.errType);
3805                     }
3806                     return new MethodType(argtypes, Type.recoveryType,
3807                             List.of(syms.throwableType), syms.methodClass);
3808                 case REFERENCE:
3809                     return new MethodType(List.nil(), Type.recoveryType,
3810                             List.of(syms.throwableType), syms.methodClass);
3811                 default:
3812                     Assert.error("Cannot get here!");
3813             }
3814             return null;
3815         }
3816 
3817         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3818                 final InferenceContext inferenceContext, final Type... ts) {
3819             checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
3820         }
3821 
3822         private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
3823                 final InferenceContext inferenceContext, final List<Type> ts) {
3824             if (inferenceContext.free(ts)) {
3825                 inferenceContext.addFreeTypeListener(ts,
3826                         solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
3827             } else {
3828                 for (Type t : ts) {
3829                     rs.checkAccessibleType(env, t);
3830                 }
3831             }
3832         }
3833 
3834         /**
3835          * Lambda/method reference have a special check context that ensures
3836          * that i.e. a lambda return type is compatible with the expected
3837          * type according to both the inherited context and the assignment
3838          * context.
3839          */
3840         class FunctionalReturnContext extends Check.NestedCheckContext {
3841 
3842             FunctionalReturnContext(CheckContext enclosingContext) {
3843                 super(enclosingContext);
3844             }
3845 
3846             @Override
3847             public boolean compatible(Type found, Type req, Warner warn) {
3848                 //return type must be compatible in both current context and assignment context
3849                 return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
3850             }
3851 
3852             @Override
3853             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3854                 enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
3855             }
3856         }
3857 
3858         class ExpressionLambdaReturnContext extends FunctionalReturnContext {
3859 
3860             JCExpression expr;
3861             boolean expStmtExpected;
3862 
3863             ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
3864                 super(enclosingContext);
3865                 this.expr = expr;
3866             }
3867 
3868             @Override
3869             public void report(DiagnosticPosition pos, JCDiagnostic details) {
3870                 if (expStmtExpected) {
3871                     enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
3872                 } else {
3873                     super.report(pos, details);
3874                 }
3875             }
3876 
3877             @Override
3878             public boolean compatible(Type found, Type req, Warner warn) {
3879                 //a void return is compatible with an expression statement lambda
3880                 if (req.hasTag(VOID)) {
3881                     expStmtExpected = true;
3882                     return TreeInfo.isExpressionStatement(expr);
3883                 } else {
3884                     return super.compatible(found, req, warn);
3885                 }
3886             }
3887         }
3888 
3889         ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
3890             FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
3891                     new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
3892                     new FunctionalReturnContext(resultInfo.checkContext);
3893 
3894             return descriptor.getReturnType() == Type.recoveryType ?
3895                     recoveryInfo :
3896                     new ResultInfo(KindSelector.VAL,
3897                             descriptor.getReturnType(), funcContext);
3898         }
3899 
3900         /**
3901         * Lambda compatibility. Check that given return types, thrown types, parameter types
3902         * are compatible with the expected functional interface descriptor. This means that:
3903         * (i) parameter types must be identical to those of the target descriptor; (ii) return
3904         * types must be compatible with the return type of the expected descriptor.
3905         */
3906         void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
3907             Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
3908 
3909             //return values have already been checked - but if lambda has no return
3910             //values, we must ensure that void/value compatibility is correct;
3911             //this amounts at checking that, if a lambda body can complete normally,
3912             //the descriptor's return type must be void
3913             if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
3914                     !returnType.hasTag(VOID) && returnType != Type.recoveryType) {
3915                 Fragment msg =
3916                         Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
3917                 checkContext.report(tree,
3918                                     diags.fragment(msg));
3919             }
3920 
3921             List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
3922             if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
3923                 checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
3924             }
3925         }
3926 
3927         /* This method returns an environment to be used to attribute a lambda
3928          * expression.
3929          *
3930          * The owner of this environment is a method symbol. If the current owner
3931          * is not a method (e.g. if the lambda occurs in a field initializer), then
3932          * a synthetic method symbol owner is created.
3933          */
3934         public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
3935             Env<AttrContext> lambdaEnv;
3936             Symbol owner = env.info.scope.owner;
3937             if (owner.kind == VAR && owner.owner.kind == TYP) {
3938                 // If the lambda is nested in a field initializer, we need to create a fake init method.
3939                 // Uniqueness of this symbol is not important (as e.g. annotations will be added on the
3940                 // init symbol's owner).
3941                 ClassSymbol enclClass = owner.enclClass();
3942                 Name initName = owner.isStatic() ? names.clinit : names.init;
3943                 MethodSymbol initSym = new MethodSymbol(BLOCK | (owner.isStatic() ? STATIC : 0) | SYNTHETIC | PRIVATE,
3944                         initName, initBlockType, enclClass);
3945                 initSym.params = List.nil();
3946                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(initSym)));
3947             } else {
3948                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
3949             }
3950             lambdaEnv.info.yieldResult = null;
3951             lambdaEnv.info.isLambda = true;
3952             return lambdaEnv;
3953         }
3954 
3955     @Override
3956     public void visitReference(final JCMemberReference that) {
3957         if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
3958             if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
3959                 //method reference only allowed in assignment or method invocation/cast context
3960                 log.error(that.pos(), Errors.UnexpectedMref);
3961             }
3962             result = that.type = types.createErrorType(pt());
3963             return;
3964         }
3965         final Env<AttrContext> localEnv = env.dup(that);
3966         try {
3967             //attribute member reference qualifier - if this is a constructor
3968             //reference, the expected kind must be a type
3969             Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
3970 
3971             if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
3972                 exprType = chk.checkConstructorRefType(that.expr, exprType);
3973                 if (!exprType.isErroneous() &&
3974                     exprType.isRaw() &&
3975                     that.typeargs != null) {
3976                     log.error(that.expr.pos(),
3977                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
3978                                                  Fragments.MrefInferAndExplicitParams));
3979                     exprType = types.createErrorType(exprType);
3980                 }
3981             }
3982 
3983             if (exprType.isErroneous()) {
3984                 //if the qualifier expression contains problems,
3985                 //give up attribution of method reference
3986                 result = that.type = exprType;
3987                 return;
3988             }
3989 
3990             if (TreeInfo.isStaticSelector(that.expr, names)) {
3991                 //if the qualifier is a type, validate it; raw warning check is
3992                 //omitted as we don't know at this stage as to whether this is a
3993                 //raw selector (because of inference)
3994                 chk.validate(that.expr, env, false);
3995             } else {
3996                 Symbol lhsSym = TreeInfo.symbol(that.expr);
3997                 localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
3998             }
3999             //attrib type-arguments
4000             List<Type> typeargtypes = List.nil();
4001             if (that.typeargs != null) {
4002                 typeargtypes = attribTypes(that.typeargs, localEnv);
4003             }
4004 
4005             boolean isTargetSerializable =
4006                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
4007                     rs.isSerializable(pt());
4008             TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
4009             Type currentTarget = targetInfo.target;
4010             Type desc = targetInfo.descriptor;
4011 
4012             setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
4013             List<Type> argtypes = desc.getParameterTypes();
4014             Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
4015 
4016             if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
4017                 referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
4018             }
4019 
4020             Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
4021             List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
4022             try {
4023                 refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
4024                         that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
4025                         resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
4026             } finally {
4027                 resultInfo.checkContext.inferenceContext().rollback(saved_undet);
4028             }
4029 
4030             Symbol refSym = refResult.fst;
4031             Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
4032 
4033             /** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
4034              *  JDK-8075541
4035              */
4036             if (refSym.kind != MTH) {
4037                 boolean targetError;
4038                 switch (refSym.kind) {
4039                     case ABSENT_MTH:
4040                         targetError = false;
4041                         break;
4042                     case WRONG_MTH:
4043                     case WRONG_MTHS:
4044                     case AMBIGUOUS:
4045                     case HIDDEN:
4046                     case STATICERR:
4047                         targetError = true;
4048                         break;
4049                     default:
4050                         Assert.error("unexpected result kind " + refSym.kind);
4051                         targetError = false;
4052                 }
4053 
4054                 JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
4055                         .getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
4056                                 that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
4057 
4058                 JCDiagnostic diag = diags.create(log.currentSource(), that,
4059                         targetError ?
4060                             Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
4061                             Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
4062 
4063                 if (targetError && currentTarget == Type.recoveryType) {
4064                     //a target error doesn't make sense during recovery stage
4065                     //as we don't know what actual parameter types are
4066                     result = that.type = currentTarget;
4067                     return;
4068                 } else {
4069                     if (targetError) {
4070                         resultInfo.checkContext.report(that, diag);
4071                     } else {
4072                         log.report(diag);
4073                     }
4074                     result = that.type = types.createErrorType(currentTarget);
4075                     return;
4076                 }
4077             }
4078 
4079             that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
4080             that.kind = lookupHelper.referenceKind(that.sym);
4081             that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
4082 
4083             if (desc.getReturnType() == Type.recoveryType) {
4084                 // stop here
4085                 result = that.type = currentTarget;
4086                 return;
4087             }
4088 
4089             if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
4090                 checkNewInnerClass(that.pos(), env, exprType, false);
4091             }
4092 
4093             if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
4094 
4095                 if (that.getMode() == ReferenceMode.INVOKE &&
4096                         TreeInfo.isStaticSelector(that.expr, names) &&
4097                         that.kind.isUnbound() &&
4098                         lookupHelper.site.isRaw()) {
4099                     chk.checkRaw(that.expr, localEnv);
4100                 }
4101 
4102                 if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
4103                         exprType.getTypeArguments().nonEmpty()) {
4104                     //static ref with class type-args
4105                     log.error(that.expr.pos(),
4106                               Errors.InvalidMref(Kinds.kindName(that.getMode()),
4107                                                  Fragments.StaticMrefWithTargs));
4108                     result = that.type = types.createErrorType(currentTarget);
4109                     return;
4110                 }
4111 
4112                 if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
4113                     // Check that super-qualified symbols are not abstract (JLS)
4114                     rs.checkNonAbstract(that.pos(), that.sym);
4115                 }
4116 
4117                 if (isTargetSerializable) {
4118                     chk.checkAccessFromSerializableElement(that, true);
4119                 }
4120             }
4121 
4122             ResultInfo checkInfo =
4123                     resultInfo.dup(newMethodTemplate(
4124                         desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
4125                         that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
4126                         new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
4127 
4128             Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
4129 
4130             if (that.kind.isUnbound() &&
4131                     resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
4132                 //re-generate inference constraints for unbound receiver
4133                 if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
4134                     //cannot happen as this has already been checked - we just need
4135                     //to regenerate the inference constraints, as that has been lost
4136                     //as a result of the call to inferenceContext.save()
4137                     Assert.error("Can't get here");
4138                 }
4139             }
4140 
4141             if (!refType.isErroneous()) {
4142                 refType = types.createMethodTypeWithReturn(refType,
4143                         adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
4144             }
4145 
4146             //go ahead with standard method reference compatibility check - note that param check
4147             //is a no-op (as this has been taken care during method applicability)
4148             boolean isSpeculativeRound =
4149                     resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
4150 
4151             that.type = currentTarget; //avoids recovery at this stage
4152             checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
4153             if (!isSpeculativeRound) {
4154                 checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
4155             }
4156             chk.checkRequiresIdentity(that, localEnv.info.lint);
4157             result = check(that, currentTarget, KindSelector.VAL, resultInfo);
4158         } catch (Types.FunctionDescriptorLookupError ex) {
4159             JCDiagnostic cause = ex.getDiagnostic();
4160             resultInfo.checkContext.report(that, cause);
4161             result = that.type = types.createErrorType(pt());
4162             return;
4163         }
4164     }
4165     //where
4166         ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
4167             //if this is a constructor reference, the expected kind must be a type
4168             return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
4169                                   KindSelector.VAL_TYP : KindSelector.TYP,
4170                                   Type.noType);
4171         }
4172 
4173 
4174     @SuppressWarnings("fallthrough")
4175     void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
4176         InferenceContext inferenceContext = checkContext.inferenceContext();
4177         Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
4178 
4179         Type resType;
4180         switch (tree.getMode()) {
4181             case NEW:
4182                 if (!tree.expr.type.isRaw()) {
4183                     resType = tree.expr.type;
4184                     break;
4185                 }
4186             default:
4187                 resType = refType.getReturnType();
4188         }
4189 
4190         Type incompatibleReturnType = resType;
4191 
4192         if (returnType.hasTag(VOID)) {
4193             incompatibleReturnType = null;
4194         }
4195 
4196         if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
4197             if (resType.isErroneous() ||
4198                     new FunctionalReturnContext(checkContext).compatible(resType, returnType,
4199                             checkContext.checkWarner(tree, resType, returnType))) {
4200                 incompatibleReturnType = null;
4201             }
4202         }
4203 
4204         if (incompatibleReturnType != null) {
4205             Fragment msg =
4206                     Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
4207             checkContext.report(tree, diags.fragment(msg));
4208         } else {
4209             if (inferenceContext.free(refType)) {
4210                 // we need to wait for inference to finish and then replace inference vars in the referent type
4211                 inferenceContext.addFreeTypeListener(List.of(refType),
4212                         instantiatedContext -> {
4213                             tree.referentType = instantiatedContext.asInstType(refType);
4214                         });
4215             } else {
4216                 tree.referentType = refType;
4217             }
4218         }
4219 
4220         if (!speculativeAttr) {
4221             if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
4222                 log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
4223             }
4224         }
4225     }
4226 
4227     boolean checkExConstraints(
4228             List<Type> thrownByFuncExpr,
4229             List<Type> thrownAtFuncType,
4230             InferenceContext inferenceContext) {
4231         /** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
4232          *  are not proper types
4233          */
4234         List<Type> nonProperList = thrownAtFuncType.stream()
4235                 .filter(e -> inferenceContext.free(e)).collect(List.collector());
4236         List<Type> properList = thrownAtFuncType.diff(nonProperList);
4237 
4238         /** Let X1,...,Xm be the checked exception types that the lambda body can throw or
4239          *  in the throws clause of the invocation type of the method reference's compile-time
4240          *  declaration
4241          */
4242         List<Type> checkedList = thrownByFuncExpr.stream()
4243                 .filter(e -> chk.isChecked(e)).collect(List.collector());
4244 
4245         /** If n = 0 (the function type's throws clause consists only of proper types), then
4246          *  if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
4247          *  in the throws clause, the constraint reduces to false; otherwise, the constraint
4248          *  reduces to true
4249          */
4250         ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
4251         for (Type checked : checkedList) {
4252             boolean isSubtype = false;
4253             for (Type proper : properList) {
4254                 if (types.isSubtype(checked, proper)) {
4255                     isSubtype = true;
4256                     break;
4257                 }
4258             }
4259             if (!isSubtype) {
4260                 uncaughtByProperTypes.add(checked);
4261             }
4262         }
4263 
4264         if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
4265             return false;
4266         }
4267 
4268         /** If n > 0, the constraint reduces to a set of subtyping constraints:
4269          *  for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
4270          *  throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
4271          */
4272         List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
4273         uncaughtByProperTypes.forEach(checkedEx -> {
4274             nonProperAsUndet.forEach(nonProper -> {
4275                 types.isSubtype(checkedEx, nonProper);
4276             });
4277         });
4278 
4279         /** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
4280          */
4281         nonProperAsUndet.stream()
4282                 .filter(t -> t.hasTag(UNDETVAR))
4283                 .forEach(t -> ((UndetVar)t).setThrow());
4284         return true;
4285     }
4286 
4287     /**
4288      * Set functional type info on the underlying AST. Note: as the target descriptor
4289      * might contain inference variables, we might need to register an hook in the
4290      * current inference context.
4291      */
4292     private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
4293             final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
4294         if (checkContext.inferenceContext().free(descriptorType)) {
4295             checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
4296                     inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
4297                     inferenceContext.asInstType(primaryTarget), checkContext));
4298         } else {
4299             fExpr.owner = env.info.scope.owner;
4300             if (pt.hasTag(CLASS)) {
4301                 fExpr.target = primaryTarget;
4302             }
4303             if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
4304                     pt != Type.recoveryType) {
4305                 //check that functional interface class is well-formed
4306                 try {
4307                     /* Types.makeFunctionalInterfaceClass() may throw an exception
4308                      * when it's executed post-inference. See the listener code
4309                      * above.
4310                      */
4311                     ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
4312                             names.empty, fExpr.target, ABSTRACT);
4313                     if (csym != null) {
4314                         chk.checkImplementations(env.tree, csym, csym);
4315                         try {
4316                             //perform an additional functional interface check on the synthetic class,
4317                             //as there may be spurious errors for raw targets - because of existing issues
4318                             //with membership and inheritance (see JDK-8074570).
4319                             csym.flags_field |= INTERFACE;
4320                             types.findDescriptorType(csym.type);
4321                         } catch (FunctionDescriptorLookupError err) {
4322                             resultInfo.checkContext.report(fExpr,
4323                                     diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
4324                         }
4325                     }
4326                 } catch (Types.FunctionDescriptorLookupError ex) {
4327                     JCDiagnostic cause = ex.getDiagnostic();
4328                     resultInfo.checkContext.report(env.tree, cause);
4329                 }
4330             }
4331         }
4332     }
4333 
4334     public void visitParens(JCParens tree) {
4335         Type owntype = attribTree(tree.expr, env, resultInfo);
4336         result = check(tree, owntype, pkind(), resultInfo);
4337         Symbol sym = TreeInfo.symbol(tree);
4338         if (sym != null && sym.kind.matches(KindSelector.TYP_PCK) && sym.kind != Kind.ERR)
4339             log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
4340     }
4341 
4342     public void visitAssign(JCAssign tree) {
4343         Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
4344         Type capturedType = capture(owntype);
4345         attribExpr(tree.rhs, env, owntype);
4346         result = check(tree, capturedType, KindSelector.VAL, resultInfo);
4347     }
4348 
4349     public void visitAssignop(JCAssignOp tree) {
4350         // Attribute arguments.
4351         Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
4352         Type operand = attribExpr(tree.rhs, env);
4353         // Find operator.
4354         Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
4355         if (operator != operators.noOpSymbol &&
4356                 !owntype.isErroneous() &&
4357                 !operand.isErroneous()) {
4358             chk.checkDivZero(tree.rhs.pos(), operator, operand);
4359             chk.checkCastable(tree.rhs.pos(),
4360                               operator.type.getReturnType(),
4361                               owntype);
4362             chk.checkLossOfPrecision(tree.rhs.pos(), operand, owntype);
4363         }
4364         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4365     }
4366 
4367     public void visitUnary(JCUnary tree) {
4368         // Attribute arguments.
4369         Type argtype = (tree.getTag().isIncOrDecUnaryOp())
4370             ? attribTree(tree.arg, env, varAssignmentInfo)
4371             : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
4372 
4373         // Find operator.
4374         OperatorSymbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
4375         Type owntype = types.createErrorType(tree.type);
4376         if (operator != operators.noOpSymbol &&
4377                 !argtype.isErroneous()) {
4378             owntype = (tree.getTag().isIncOrDecUnaryOp())
4379                 ? tree.arg.type
4380                 : operator.type.getReturnType();
4381             int opc = operator.opcode;
4382 
4383             // If the argument is constant, fold it.
4384             if (argtype.constValue() != null) {
4385                 Type ctype = cfolder.fold1(opc, argtype);
4386                 if (ctype != null) {
4387                     owntype = cfolder.coerce(ctype, owntype);
4388                 }
4389             }
4390         }
4391         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4392         matchBindings = matchBindingsComputer.unary(tree, matchBindings);
4393     }
4394 
4395     public void visitBinary(JCBinary tree) {
4396         // Attribute arguments.
4397         Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
4398         // x && y
4399         // include x's bindings when true in y
4400 
4401         // x || y
4402         // include x's bindings when false in y
4403 
4404         MatchBindings lhsBindings = matchBindings;
4405         List<BindingSymbol> propagatedBindings;
4406         switch (tree.getTag()) {
4407             case AND:
4408                 propagatedBindings = lhsBindings.bindingsWhenTrue;
4409                 break;
4410             case OR:
4411                 propagatedBindings = lhsBindings.bindingsWhenFalse;
4412                 break;
4413             default:
4414                 propagatedBindings = List.nil();
4415                 break;
4416         }
4417         Env<AttrContext> rhsEnv = bindingEnv(env, propagatedBindings);
4418         Type right;
4419         try {
4420             right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
4421         } finally {
4422             rhsEnv.info.scope.leave();
4423         }
4424 
4425         matchBindings = matchBindingsComputer.binary(tree, lhsBindings, matchBindings);
4426 
4427         // Find operator.
4428         OperatorSymbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
4429         Type owntype = types.createErrorType(tree.type);
4430         if (operator != operators.noOpSymbol &&
4431                 !left.isErroneous() &&
4432                 !right.isErroneous()) {
4433             owntype = operator.type.getReturnType();
4434             int opc = operator.opcode;
4435             // If both arguments are constants, fold them.
4436             if (left.constValue() != null && right.constValue() != null) {
4437                 Type ctype = cfolder.fold2(opc, left, right);
4438                 if (ctype != null) {
4439                     owntype = cfolder.coerce(ctype, owntype);
4440                 }
4441             }
4442 
4443             // Check that argument types of a reference ==, != are
4444             // castable to each other, (JLS 15.21).  Note: unboxing
4445             // comparisons will not have an acmp* opc at this point.
4446             if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
4447                 if (!types.isCastable(left, right, new Warner(tree.pos()))) {
4448                     log.error(tree.pos(), Errors.IncomparableTypes(left, right));
4449                 }
4450             }
4451 
4452             chk.checkDivZero(tree.rhs.pos(), operator, right);
4453         }
4454         result = check(tree, owntype, KindSelector.VAL, resultInfo);
4455     }
4456 
4457     public void visitTypeCast(final JCTypeCast tree) {
4458         Type clazztype = attribType(tree.clazz, env);
4459         chk.validate(tree.clazz, env, false);
4460         chk.checkRequiresIdentity(tree, env.info.lint);
4461         //a fresh environment is required for 292 inference to work properly ---
4462         //see Infer.instantiatePolymorphicSignatureInstance()
4463         Env<AttrContext> localEnv = env.dup(tree);
4464         //should we propagate the target type?
4465         final ResultInfo castInfo;
4466         JCExpression expr = TreeInfo.skipParens(tree.expr);
4467         boolean isPoly = (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
4468         if (isPoly) {
4469             //expression is a poly - we need to propagate target type info
4470             castInfo = new ResultInfo(KindSelector.VAL, clazztype,
4471                                       new Check.NestedCheckContext(resultInfo.checkContext) {
4472                 @Override
4473                 public boolean compatible(Type found, Type req, Warner warn) {
4474                     return types.isCastable(found, req, warn);
4475                 }
4476             });
4477         } else {
4478             //standalone cast - target-type info is not propagated
4479             castInfo = unknownExprInfo;
4480         }
4481         Type exprtype = attribTree(tree.expr, localEnv, castInfo);
4482         Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4483         if (exprtype.constValue() != null)
4484             owntype = cfolder.coerce(exprtype, owntype);
4485         result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
4486         if (!isPoly)
4487             chk.checkRedundantCast(localEnv, tree);
4488     }
4489 
4490     public void visitTypeTest(JCInstanceOf tree) {
4491         Type exprtype = attribExpr(tree.expr, env);
4492         if (exprtype.isPrimitive()) {
4493             preview.checkSourceLevel(tree.expr.pos(), Feature.PRIMITIVE_PATTERNS);
4494         } else {
4495             exprtype = chk.checkNullOrRefType(
4496                     tree.expr.pos(), exprtype);
4497         }
4498         Type clazztype;
4499         JCTree typeTree;
4500         if (tree.pattern.getTag() == BINDINGPATTERN ||
4501             tree.pattern.getTag() == RECORDPATTERN) {
4502             attribExpr(tree.pattern, env, exprtype);
4503             clazztype = tree.pattern.type;
4504             if (types.isSubtype(exprtype, clazztype) &&
4505                 !exprtype.isErroneous() && !clazztype.isErroneous() &&
4506                 tree.pattern.getTag() != RECORDPATTERN) {
4507                 if (!allowUnconditionalPatternsInstanceOf) {
4508                     log.error(tree.pos(), Feature.UNCONDITIONAL_PATTERN_IN_INSTANCEOF.error(this.sourceName));
4509                 }
4510             }
4511             typeTree = TreeInfo.primaryPatternTypeTree((JCPattern) tree.pattern);
4512         } else {
4513             clazztype = attribType(tree.pattern, env);
4514             typeTree = tree.pattern;
4515             chk.validate(typeTree, env, false);
4516         }
4517         if (clazztype.isPrimitive()) {
4518             preview.checkSourceLevel(tree.pattern.pos(), Feature.PRIMITIVE_PATTERNS);
4519         } else {
4520             if (!clazztype.hasTag(TYPEVAR)) {
4521                 clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
4522             }
4523             if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
4524                 boolean valid = false;
4525                 if (allowReifiableTypesInInstanceof) {
4526                     valid = checkCastablePattern(tree.expr.pos(), exprtype, clazztype);
4527                 } else {
4528                     log.error(tree.pos(), Feature.REIFIABLE_TYPES_INSTANCEOF.error(this.sourceName));
4529                     allowReifiableTypesInInstanceof = true;
4530                 }
4531                 if (!valid) {
4532                     clazztype = types.createErrorType(clazztype);
4533                 }
4534             }
4535         }
4536         chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
4537         result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
4538     }
4539 
4540     private boolean checkCastablePattern(DiagnosticPosition pos,
4541                                          Type exprType,
4542                                          Type pattType) {
4543         Warner warner = new Warner();
4544         // if any type is erroneous, the problem is reported elsewhere
4545         if (exprType.isErroneous() || pattType.isErroneous()) {
4546             return false;
4547         }
4548         if (!types.isCastable(exprType, pattType, warner)) {
4549             chk.basicHandler.report(pos,
4550                     diags.fragment(Fragments.InconvertibleTypes(exprType, pattType)));
4551             return false;
4552         } else if ((exprType.isPrimitive() || pattType.isPrimitive()) &&
4553                 (!exprType.isPrimitive() || !pattType.isPrimitive() || !types.isSameType(exprType, pattType))) {
4554             preview.checkSourceLevel(pos, Feature.PRIMITIVE_PATTERNS);
4555             return true;
4556         } else if (warner.hasLint(LintCategory.UNCHECKED)) {
4557             log.error(pos,
4558                     Errors.InstanceofReifiableNotSafe(exprType, pattType));
4559             return false;
4560         } else {
4561             return true;
4562         }
4563     }
4564 
4565     @Override
4566     public void visitAnyPattern(JCAnyPattern tree) {
4567         result = tree.type = resultInfo.pt;
4568     }
4569 
4570     public void visitBindingPattern(JCBindingPattern tree) {
4571         Type type;
4572         if (tree.var.vartype != null) {
4573             type = attribType(tree.var.vartype, env);
4574         } else {
4575             type = resultInfo.pt;
4576         }
4577         tree.type = tree.var.type = type;
4578         BindingSymbol v = new BindingSymbol(tree.var.mods.flags, tree.var.name, type, env.info.scope.owner);
4579         v.pos = tree.pos;
4580         tree.var.sym = v;
4581         if (chk.checkUnique(tree.var.pos(), v, env.info.scope)) {
4582             chk.checkTransparentVar(tree.var.pos(), v, env.info.scope);
4583         }
4584         chk.validate(tree.var.vartype, env, true);
4585         if (tree.var.isImplicitlyTyped()) {
4586             setSyntheticVariableType(tree.var, type == Type.noType ? syms.errType
4587                                                                    : type);
4588         }
4589         annotate.annotateLater(tree.var.mods.annotations, env, v);
4590         if (!tree.var.isImplicitlyTyped()) {
4591             annotate.queueScanTreeAndTypeAnnotate(tree.var.vartype, env, v);
4592         }
4593         annotate.flush();
4594         result = tree.type;
4595         if (v.isUnnamedVariable()) {
4596             matchBindings = MatchBindingsComputer.EMPTY;
4597         } else {
4598             matchBindings = new MatchBindings(List.of(v), List.nil());
4599         }
4600         chk.checkRequiresIdentity(tree, env.info.lint);
4601     }
4602 
4603     @Override
4604     public void visitRecordPattern(JCRecordPattern tree) {
4605         Type site;
4606 
4607         if (tree.deconstructor == null) {
4608             log.error(tree.pos(), Errors.DeconstructionPatternVarNotAllowed);
4609             tree.record = syms.errSymbol;
4610             site = tree.type = types.createErrorType(tree.record.type);
4611         } else {
4612             Type type = attribType(tree.deconstructor, env);
4613             if (type.isRaw() && type.tsym.getTypeParameters().nonEmpty()) {
4614                 Type inferred = infer.instantiatePatternType(resultInfo.pt, type.tsym);
4615                 if (inferred == null) {
4616                     log.error(tree.pos(), Errors.PatternTypeCannotInfer);
4617                 } else {
4618                     type = inferred;
4619                 }
4620             }
4621             tree.type = tree.deconstructor.type = type;
4622             site = types.capture(tree.type);
4623         }
4624 
4625         List<Type> expectedRecordTypes;
4626         if (site.tsym.kind == Kind.TYP && ((ClassSymbol) site.tsym).isRecord()) {
4627             ClassSymbol record = (ClassSymbol) site.tsym;
4628             expectedRecordTypes = record.getRecordComponents()
4629                                         .stream()
4630                                         .map(rc -> types.memberType(site, rc))
4631                                         .map(t -> types.upward(t, types.captures(t)).baseType())
4632                                         .collect(List.collector());
4633             tree.record = record;
4634         } else {
4635             log.error(tree.pos(), Errors.DeconstructionPatternOnlyRecords(site.tsym));
4636             expectedRecordTypes = Stream.generate(() -> types.createErrorType(tree.type))
4637                                 .limit(tree.nested.size())
4638                                 .collect(List.collector());
4639             tree.record = syms.errSymbol;
4640         }
4641         ListBuffer<BindingSymbol> outBindings = new ListBuffer<>();
4642         List<Type> recordTypes = expectedRecordTypes;
4643         List<JCPattern> nestedPatterns = tree.nested;
4644         Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
4645         try {
4646             while (recordTypes.nonEmpty() && nestedPatterns.nonEmpty()) {
4647                 attribExpr(nestedPatterns.head, localEnv, recordTypes.head);
4648                 checkCastablePattern(nestedPatterns.head.pos(), recordTypes.head, nestedPatterns.head.type);
4649                 outBindings.addAll(matchBindings.bindingsWhenTrue);
4650                 matchBindings.bindingsWhenTrue.forEach(localEnv.info.scope::enter);
4651                 nestedPatterns = nestedPatterns.tail;
4652                 recordTypes = recordTypes.tail;
4653             }
4654             if (recordTypes.nonEmpty() || nestedPatterns.nonEmpty()) {
4655                 while (nestedPatterns.nonEmpty()) {
4656                     attribExpr(nestedPatterns.head, localEnv, Type.noType);
4657                     nestedPatterns = nestedPatterns.tail;
4658                 }
4659                 List<Type> nestedTypes =
4660                         tree.nested.stream().map(p -> p.type).collect(List.collector());
4661                 log.error(tree.pos(),
4662                           Errors.IncorrectNumberOfNestedPatterns(expectedRecordTypes,
4663                                                                  nestedTypes));
4664             }
4665         } finally {
4666             localEnv.info.scope.leave();
4667         }
4668         chk.validate(tree.deconstructor, env, true);
4669         result = tree.type;
4670         matchBindings = new MatchBindings(outBindings.toList(), List.nil());
4671     }
4672 
4673     public void visitIndexed(JCArrayAccess tree) {
4674         Type owntype = types.createErrorType(tree.type);
4675         Type atype = attribExpr(tree.indexed, env);
4676         attribExpr(tree.index, env, syms.intType);
4677         if (types.isArray(atype))
4678             owntype = types.elemtype(atype);
4679         else if (!atype.hasTag(ERROR))
4680             log.error(tree.pos(), Errors.ArrayReqButFound(atype));
4681         if (!pkind().contains(KindSelector.VAL))
4682             owntype = capture(owntype);
4683         result = check(tree, owntype, KindSelector.VAR, resultInfo);
4684     }
4685 
4686     public void visitIdent(JCIdent tree) {
4687         Symbol sym;
4688 
4689         // Find symbol
4690         if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
4691             // If we are looking for a method, the prototype `pt' will be a
4692             // method type with the type of the call's arguments as parameters.
4693             env.info.pendingResolutionPhase = null;
4694             sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
4695         } else if (tree.sym != null && tree.sym.kind != VAR) {
4696             sym = tree.sym;
4697         } else {
4698             sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
4699         }
4700         tree.sym = sym;
4701 
4702         // Also find the environment current for the class where
4703         // sym is defined (`symEnv').
4704         Env<AttrContext> symEnv = env;
4705         if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
4706             sym.kind.matches(KindSelector.VAL_MTH) &&
4707             sym.owner.kind == TYP &&
4708             tree.name != names._this && tree.name != names._super) {
4709 
4710             // Find environment in which identifier is defined.
4711             while (symEnv.outer != null &&
4712                    !sym.isMemberOf(symEnv.enclClass.sym, types)) {
4713                 symEnv = symEnv.outer;
4714             }
4715         }
4716 
4717         // If symbol is a variable, ...
4718         if (sym.kind == VAR) {
4719             VarSymbol v = (VarSymbol)sym;
4720 
4721             // ..., evaluate its initializer, if it has one, and check for
4722             // illegal forward reference.
4723             checkInit(tree, env, v, false);
4724 
4725             // If we are expecting a variable (as opposed to a value), check
4726             // that the variable is assignable in the current environment.
4727             if (KindSelector.ASG.subset(pkind()))
4728                 checkAssignable(tree.pos(), v, null, env);
4729         }
4730 
4731         Env<AttrContext> env1 = env;
4732         if (sym.kind != ERR && sym.kind != TYP &&
4733             sym.owner != null && sym.owner != env1.enclClass.sym) {
4734             // If the found symbol is inaccessible, then it is
4735             // accessed through an enclosing instance.  Locate this
4736             // enclosing instance:
4737             while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
4738                 env1 = env1.outer;
4739         }
4740 
4741         if (env.info.isSerializable) {
4742             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4743         }
4744 
4745         result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
4746     }
4747 
4748     public void visitSelect(JCFieldAccess tree) {
4749         // Determine the expected kind of the qualifier expression.
4750         KindSelector skind = KindSelector.NIL;
4751         if (tree.name == names._this || tree.name == names._super ||
4752                 tree.name == names._class)
4753         {
4754             skind = KindSelector.TYP;
4755         } else {
4756             if (pkind().contains(KindSelector.PCK))
4757                 skind = KindSelector.of(skind, KindSelector.PCK);
4758             if (pkind().contains(KindSelector.TYP))
4759                 skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
4760             if (pkind().contains(KindSelector.VAL_MTH))
4761                 skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
4762         }
4763 
4764         // Attribute the qualifier expression, and determine its symbol (if any).
4765         Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
4766         Assert.check(site == tree.selected.type);
4767         if (!pkind().contains(KindSelector.TYP_PCK))
4768             site = capture(site); // Capture field access
4769 
4770         // don't allow T.class T[].class, etc
4771         if (skind == KindSelector.TYP) {
4772             Type elt = site;
4773             while (elt.hasTag(ARRAY))
4774                 elt = ((ArrayType)elt).elemtype;
4775             if (elt.hasTag(TYPEVAR)) {
4776                 log.error(tree.pos(), Errors.TypeVarCantBeDeref);
4777                 result = tree.type = types.createErrorType(tree.name, site.tsym, site);
4778                 tree.sym = tree.type.tsym;
4779                 return ;
4780             }
4781         }
4782 
4783         // If qualifier symbol is a type or `super', assert `selectSuper'
4784         // for the selection. This is relevant for determining whether
4785         // protected symbols are accessible.
4786         Symbol sitesym = TreeInfo.symbol(tree.selected);
4787         boolean selectSuperPrev = env.info.selectSuper;
4788         env.info.selectSuper =
4789             sitesym != null &&
4790             sitesym.name == names._super;
4791 
4792         // Determine the symbol represented by the selection.
4793         env.info.pendingResolutionPhase = null;
4794         Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
4795         if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
4796             log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
4797             sym = syms.errSymbol;
4798         }
4799         if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
4800             site = capture(site);
4801             sym = selectSym(tree, sitesym, site, env, resultInfo);
4802         }
4803         boolean varArgs = env.info.lastResolveVarargs();
4804         tree.sym = sym;
4805 
4806         if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
4807             site = types.skipTypeVars(site, true);
4808         }
4809 
4810         // If that symbol is a variable, ...
4811         if (sym.kind == VAR) {
4812             VarSymbol v = (VarSymbol)sym;
4813 
4814             // ..., evaluate its initializer, if it has one, and check for
4815             // illegal forward reference.
4816             checkInit(tree, env, v, true);
4817 
4818             // If we are expecting a variable (as opposed to a value), check
4819             // that the variable is assignable in the current environment.
4820             if (KindSelector.ASG.subset(pkind()))
4821                 checkAssignable(tree.pos(), v, tree.selected, env);
4822         }
4823 
4824         if (sitesym != null &&
4825                 sitesym.kind == VAR &&
4826                 ((VarSymbol)sitesym).isResourceVariable() &&
4827                 sym.kind == MTH &&
4828                 sym.name.equals(names.close) &&
4829                 sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true)) {
4830             log.warning(tree, LintWarnings.TryExplicitCloseCall);
4831         }
4832 
4833         // Disallow selecting a type from an expression
4834         if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
4835             tree.type = check(tree.selected, pt(),
4836                               sitesym == null ?
4837                                       KindSelector.VAL : sitesym.kind.toSelector(),
4838                               new ResultInfo(KindSelector.TYP_PCK, pt()));
4839         }
4840 
4841         if (isType(sitesym)) {
4842             if (sym.name != names._this && sym.name != names._super) {
4843                 // Check if type-qualified fields or methods are static (JLS)
4844                 if ((sym.flags() & STATIC) == 0 &&
4845                     sym.name != names._super &&
4846                     (sym.kind == VAR || sym.kind == MTH)) {
4847                     rs.accessBase(rs.new StaticError(sym),
4848                               tree.pos(), site, sym.name, true);
4849                 }
4850             }
4851         } else if (sym.kind != ERR &&
4852                    (sym.flags() & STATIC) != 0 &&
4853                    sym.name != names._class) {
4854             // If the qualified item is not a type and the selected item is static, report
4855             // a warning. Make allowance for the class of an array type e.g. Object[].class)
4856             if (!sym.owner.isAnonymous()) {
4857                 log.warning(tree, LintWarnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
4858             } else {
4859                 log.warning(tree, LintWarnings.StaticNotQualifiedByType2(sym.kind.kindName()));
4860             }
4861         }
4862 
4863         // If we are selecting an instance member via a `super', ...
4864         if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
4865 
4866             // Check that super-qualified symbols are not abstract (JLS)
4867             rs.checkNonAbstract(tree.pos(), sym);
4868 
4869             if (site.isRaw()) {
4870                 // Determine argument types for site.
4871                 Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
4872                 if (site1 != null) site = site1;
4873             }
4874         }
4875 
4876         if (env.info.isSerializable) {
4877             chk.checkAccessFromSerializableElement(tree, env.info.isSerializableLambda);
4878         }
4879 
4880         env.info.selectSuper = selectSuperPrev;
4881         result = checkId(tree, site, sym, env, resultInfo);
4882     }
4883     //where
4884         /** Determine symbol referenced by a Select expression,
4885          *
4886          *  @param tree   The select tree.
4887          *  @param site   The type of the selected expression,
4888          *  @param env    The current environment.
4889          *  @param resultInfo The current result.
4890          */
4891         private Symbol selectSym(JCFieldAccess tree,
4892                                  Symbol location,
4893                                  Type site,
4894                                  Env<AttrContext> env,
4895                                  ResultInfo resultInfo) {
4896             DiagnosticPosition pos = tree.pos();
4897             Name name = tree.name;
4898             switch (site.getTag()) {
4899             case PACKAGE:
4900                 return rs.accessBase(
4901                     rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
4902                     pos, location, site, name, true);
4903             case ARRAY:
4904             case CLASS:
4905                 if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
4906                     return rs.resolveQualifiedMethod(
4907                         pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
4908                 } else if (name == names._this || name == names._super) {
4909                     return rs.resolveSelf(pos, env, site.tsym, tree);
4910                 } else if (name == names._class) {
4911                     // In this case, we have already made sure in
4912                     // visitSelect that qualifier expression is a type.
4913                     return syms.getClassField(site, types);
4914                 } else {
4915                     // We are seeing a plain identifier as selector.
4916                     Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
4917                         sym = rs.accessBase(sym, pos, location, site, name, true);
4918                     return sym;
4919                 }
4920             case WILDCARD:
4921                 throw new AssertionError(tree);
4922             case TYPEVAR:
4923                 // Normally, site.getUpperBound() shouldn't be null.
4924                 // It should only happen during memberEnter/attribBase
4925                 // when determining the supertype which *must* be
4926                 // done before attributing the type variables.  In
4927                 // other words, we are seeing this illegal program:
4928                 // class B<T> extends A<T.foo> {}
4929                 Symbol sym = (site.getUpperBound() != null)
4930                     ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
4931                     : null;
4932                 if (sym == null) {
4933                     log.error(pos, Errors.TypeVarCantBeDeref);
4934                     return syms.errSymbol;
4935                 } else {
4936                     // JLS 4.9 specifies the members are derived by inheritance.
4937                     // We skip inducing a whole class by filtering members that
4938                     // can never be inherited:
4939                     Symbol sym2;
4940                     if (sym.isPrivate()) {
4941                         // Private members
4942                         sym2 = rs.new AccessError(env, site, sym);
4943                     } else if (sym.owner.isInterface() && sym.kind == MTH && (sym.flags() & STATIC) != 0) {
4944                         // Interface static methods
4945                         sym2 = rs.new SymbolNotFoundError(ABSENT_MTH);
4946                     } else {
4947                         sym2 = sym;
4948                     }
4949                     rs.accessBase(sym2, pos, location, site, name, true);
4950                     return sym;
4951                 }
4952             case ERROR:
4953                 // preserve identifier names through errors
4954                 return types.createErrorType(name, site.tsym, site).tsym;
4955             default:
4956                 // The qualifier expression is of a primitive type -- only
4957                 // .class is allowed for these.
4958                 if (name == names._class) {
4959                     // In this case, we have already made sure in Select that
4960                     // qualifier expression is a type.
4961                     return syms.getClassField(site, types);
4962                 } else {
4963                     log.error(pos, Errors.CantDeref(site));
4964                     return syms.errSymbol;
4965                 }
4966             }
4967         }
4968 
4969         /** Determine type of identifier or select expression and check that
4970          *  (1) the referenced symbol is not deprecated
4971          *  (2) the symbol's type is safe (@see checkSafe)
4972          *  (3) if symbol is a variable, check that its type and kind are
4973          *      compatible with the prototype and protokind.
4974          *  (4) if symbol is an instance field of a raw type,
4975          *      which is being assigned to, issue an unchecked warning if its
4976          *      type changes under erasure.
4977          *  (5) if symbol is an instance method of a raw type, issue an
4978          *      unchecked warning if its argument types change under erasure.
4979          *  If checks succeed:
4980          *    If symbol is a constant, return its constant type
4981          *    else if symbol is a method, return its result type
4982          *    otherwise return its type.
4983          *  Otherwise return errType.
4984          *
4985          *  @param tree       The syntax tree representing the identifier
4986          *  @param site       If this is a select, the type of the selected
4987          *                    expression, otherwise the type of the current class.
4988          *  @param sym        The symbol representing the identifier.
4989          *  @param env        The current environment.
4990          *  @param resultInfo    The expected result
4991          */
4992         Type checkId(JCTree tree,
4993                      Type site,
4994                      Symbol sym,
4995                      Env<AttrContext> env,
4996                      ResultInfo resultInfo) {
4997             return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
4998                     checkMethodIdInternal(tree, site, sym, env, resultInfo) :
4999                     checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
5000         }
5001 
5002         Type checkMethodIdInternal(JCTree tree,
5003                      Type site,
5004                      Symbol sym,
5005                      Env<AttrContext> env,
5006                      ResultInfo resultInfo) {
5007             if (resultInfo.pkind.contains(KindSelector.POLY)) {
5008                 return attrRecover.recoverMethodInvocation(tree, site, sym, env, resultInfo);
5009             } else {
5010                 return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
5011             }
5012         }
5013 
5014         Type checkIdInternal(JCTree tree,
5015                      Type site,
5016                      Symbol sym,
5017                      Type pt,
5018                      Env<AttrContext> env,
5019                      ResultInfo resultInfo) {
5020             Type owntype; // The computed type of this identifier occurrence.
5021             switch (sym.kind) {
5022             case TYP:
5023                 // For types, the computed type equals the symbol's type,
5024                 // except for two situations:
5025                 owntype = sym.type;
5026                 if (owntype.hasTag(CLASS)) {
5027                     chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
5028                     Type ownOuter = owntype.getEnclosingType();
5029 
5030                     // (a) If the symbol's type is parameterized, erase it
5031                     // because no type parameters were given.
5032                     // We recover generic outer type later in visitTypeApply.
5033                     if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
5034                         owntype = types.erasure(owntype);
5035                     }
5036 
5037                     // (b) If the symbol's type is an inner class, then
5038                     // we have to interpret its outer type as a superclass
5039                     // of the site type. Example:
5040                     //
5041                     // class Tree<A> { class Visitor { ... } }
5042                     // class PointTree extends Tree<Point> { ... }
5043                     // ...PointTree.Visitor...
5044                     //
5045                     // Then the type of the last expression above is
5046                     // Tree<Point>.Visitor.
5047                     else if ((ownOuter.hasTag(CLASS) || ownOuter.hasTag(TYPEVAR)) && site != ownOuter) {
5048                         Type normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
5049                         if (normOuter == null) // perhaps from an import
5050                             normOuter = types.erasure(ownOuter);
5051                         if (normOuter != ownOuter)
5052                             owntype = new ClassType(
5053                                 normOuter, List.nil(), owntype.tsym,
5054                                 owntype.getMetadata());
5055                     }
5056                 }
5057                 break;
5058             case VAR:
5059                 VarSymbol v = (VarSymbol)sym;
5060 
5061                 if (env.info.enclVar != null
5062                         && v.type.hasTag(NONE)) {
5063                     //self reference to implicitly typed variable declaration
5064                     log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
5065                     return tree.type = v.type = types.createErrorType(v.type);
5066                 }
5067 
5068                 // Test (4): if symbol is an instance field of a raw type,
5069                 // which is being assigned to, issue an unchecked warning if
5070                 // its type changes under erasure.
5071                 if (KindSelector.ASG.subset(pkind()) &&
5072                     v.owner.kind == TYP &&
5073                     (v.flags() & STATIC) == 0 &&
5074                     (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
5075                     Type s = types.asOuterSuper(site, v.owner);
5076                     if (s != null &&
5077                         s.isRaw() &&
5078                         !types.isSameType(v.type, v.erasure(types))) {
5079                         chk.warnUnchecked(tree.pos(), LintWarnings.UncheckedAssignToVar(v, s));
5080                     }
5081                 }
5082                 // The computed type of a variable is the type of the
5083                 // variable symbol, taken as a member of the site type.
5084                 owntype = (sym.owner.kind == TYP &&
5085                            sym.name != names._this && sym.name != names._super)
5086                     ? types.memberType(site, sym)
5087                     : sym.type;
5088 
5089                 // If the variable is a constant, record constant value in
5090                 // computed type.
5091                 if (v.getConstValue() != null && isStaticReference(tree))
5092                     owntype = owntype.constType(v.getConstValue());
5093 
5094                 if (resultInfo.pkind == KindSelector.VAL) {
5095                     owntype = capture(owntype); // capture "names as expressions"
5096                 }
5097                 break;
5098             case MTH: {
5099                 owntype = checkMethod(site, sym,
5100                         new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
5101                         env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
5102                         resultInfo.pt.getTypeArguments());
5103                 chk.checkRestricted(tree.pos(), sym);
5104                 break;
5105             }
5106             case PCK: case ERR:
5107                 owntype = sym.type;
5108                 break;
5109             default:
5110                 throw new AssertionError("unexpected kind: " + sym.kind +
5111                                          " in tree " + tree);
5112             }
5113 
5114             // Emit a `deprecation' warning if symbol is deprecated.
5115             // (for constructors (but not for constructor references), the error
5116             // was given when the constructor was resolved)
5117 
5118             if (sym.name != names.init || tree.hasTag(REFERENCE)) {
5119                 chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
5120                 chk.checkSunAPI(tree.pos(), sym);
5121                 chk.checkProfile(tree.pos(), sym);
5122                 chk.checkPreview(tree.pos(), env.info.scope.owner, site, sym);
5123             }
5124 
5125             if (pt.isErroneous()) {
5126                 owntype = types.createErrorType(owntype);
5127             }
5128 
5129             // If symbol is a variable, check that its type and
5130             // kind are compatible with the prototype and protokind.
5131             return check(tree, owntype, sym.kind.toSelector(), resultInfo);
5132         }
5133 
5134         /** Check that variable is initialized and evaluate the variable's
5135          *  initializer, if not yet done. Also check that variable is not
5136          *  referenced before it is defined.
5137          *  @param tree    The tree making up the variable reference.
5138          *  @param env     The current environment.
5139          *  @param v       The variable's symbol.
5140          */
5141         private void checkInit(JCTree tree,
5142                                Env<AttrContext> env,
5143                                VarSymbol v,
5144                                boolean onlyWarning) {
5145             // A forward reference is diagnosed if the declaration position
5146             // of the variable is greater than the current tree position
5147             // and the tree and variable definition occur in the same class
5148             // definition.  Note that writes don't count as references.
5149             // This check applies only to class and instance
5150             // variables.  Local variables follow different scope rules,
5151             // and are subject to definite assignment checking.
5152             Env<AttrContext> initEnv = enclosingInitEnv(env);
5153             if (initEnv != null &&
5154                 (initEnv.info.enclVar == v || v.pos > tree.pos) &&
5155                 v.owner.kind == TYP &&
5156                 v.owner == env.info.scope.owner.enclClass() &&
5157                 ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
5158                 (!env.tree.hasTag(ASSIGN) ||
5159                  TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
5160                 if (!onlyWarning || isStaticEnumField(v)) {
5161                     Error errkey = (initEnv.info.enclVar == v) ?
5162                                 Errors.IllegalSelfRef : Errors.IllegalForwardRef;
5163                     log.error(tree.pos(), errkey);
5164                 } else if (useBeforeDeclarationWarning) {
5165                     Warning warnkey = (initEnv.info.enclVar == v) ?
5166                                 Warnings.SelfRef(v) : Warnings.ForwardRef(v);
5167                     log.warning(tree.pos(), warnkey);
5168                 }
5169             }
5170 
5171             v.getConstValue(); // ensure initializer is evaluated
5172 
5173             checkEnumInitializer(tree, env, v);
5174         }
5175 
5176         /**
5177          * Returns the enclosing init environment associated with this env (if any). An init env
5178          * can be either a field declaration env or a static/instance initializer env.
5179          */
5180         Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
5181             while (true) {
5182                 switch (env.tree.getTag()) {
5183                     case VARDEF:
5184                         JCVariableDecl vdecl = (JCVariableDecl)env.tree;
5185                         if (vdecl.sym.owner.kind == TYP) {
5186                             //field
5187                             return env;
5188                         }
5189                         break;
5190                     case BLOCK:
5191                         if (env.next.tree.hasTag(CLASSDEF)) {
5192                             //instance/static initializer
5193                             return env;
5194                         }
5195                         break;
5196                     case METHODDEF:
5197                     case CLASSDEF:
5198                     case TOPLEVEL:
5199                         return null;
5200                 }
5201                 Assert.checkNonNull(env.next);
5202                 env = env.next;
5203             }
5204         }
5205 
5206         /**
5207          * Check for illegal references to static members of enum.  In
5208          * an enum type, constructors and initializers may not
5209          * reference its static members unless they are constant.
5210          *
5211          * @param tree    The tree making up the variable reference.
5212          * @param env     The current environment.
5213          * @param v       The variable's symbol.
5214          * @jls 8.9 Enum Types
5215          */
5216         private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
5217             // JLS:
5218             //
5219             // "It is a compile-time error to reference a static field
5220             // of an enum type that is not a compile-time constant
5221             // (15.28) from constructors, instance initializer blocks,
5222             // or instance variable initializer expressions of that
5223             // type. It is a compile-time error for the constructors,
5224             // instance initializer blocks, or instance variable
5225             // initializer expressions of an enum constant e to refer
5226             // to itself or to an enum constant of the same type that
5227             // is declared to the right of e."
5228             if (isStaticEnumField(v)) {
5229                 ClassSymbol enclClass = env.info.scope.owner.enclClass();
5230 
5231                 if (enclClass == null || enclClass.owner == null)
5232                     return;
5233 
5234                 // See if the enclosing class is the enum (or a
5235                 // subclass thereof) declaring v.  If not, this
5236                 // reference is OK.
5237                 if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
5238                     return;
5239 
5240                 // If the reference isn't from an initializer, then
5241                 // the reference is OK.
5242                 if (!Resolve.isInitializer(env))
5243                     return;
5244 
5245                 log.error(tree.pos(), Errors.IllegalEnumStaticRef);
5246             }
5247         }
5248 
5249         /** Is the given symbol a static, non-constant field of an Enum?
5250          *  Note: enum literals should not be regarded as such
5251          */
5252         private boolean isStaticEnumField(VarSymbol v) {
5253             return Flags.isEnum(v.owner) &&
5254                    Flags.isStatic(v) &&
5255                    !Flags.isConstant(v) &&
5256                    v.name != names._class;
5257         }
5258 
5259     /**
5260      * Check that method arguments conform to its instantiation.
5261      **/
5262     public Type checkMethod(Type site,
5263                             final Symbol sym,
5264                             ResultInfo resultInfo,
5265                             Env<AttrContext> env,
5266                             final List<JCExpression> argtrees,
5267                             List<Type> argtypes,
5268                             List<Type> typeargtypes) {
5269         // Test (5): if symbol is an instance method of a raw type, issue
5270         // an unchecked warning if its argument types change under erasure.
5271         if ((sym.flags() & STATIC) == 0 &&
5272             (site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
5273             Type s = types.asOuterSuper(site, sym.owner);
5274             if (s != null && s.isRaw() &&
5275                 !types.isSameTypes(sym.type.getParameterTypes(),
5276                                    sym.erasure(types).getParameterTypes())) {
5277                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedCallMbrOfRawType(sym, s));
5278             }
5279         }
5280 
5281         if (env.info.defaultSuperCallSite != null) {
5282             for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
5283                 if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
5284                         types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
5285                 List<MethodSymbol> icand_sup =
5286                         types.interfaceCandidates(sup, (MethodSymbol)sym);
5287                 if (icand_sup.nonEmpty() &&
5288                         icand_sup.head != sym &&
5289                         icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
5290                     log.error(env.tree.pos(),
5291                               Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
5292                     break;
5293                 }
5294             }
5295             env.info.defaultSuperCallSite = null;
5296         }
5297 
5298         if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
5299             JCMethodInvocation app = (JCMethodInvocation)env.tree;
5300             if (app.meth.hasTag(SELECT) &&
5301                     !TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
5302                 log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
5303             }
5304         }
5305 
5306         // Compute the identifier's instantiated type.
5307         // For methods, we need to compute the instance type by
5308         // Resolve.instantiate from the symbol's type as well as
5309         // any type arguments and value arguments.
5310         Warner noteWarner = new Warner();
5311         try {
5312             Type owntype = rs.checkMethod(
5313                     env,
5314                     site,
5315                     sym,
5316                     resultInfo,
5317                     argtypes,
5318                     typeargtypes,
5319                     noteWarner);
5320 
5321             DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
5322                 deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
5323 
5324             argtypes = argtypes.map(checkDeferredMap);
5325 
5326             if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
5327                 chk.warnUnchecked(env.tree.pos(), LintWarnings.UncheckedMethInvocationApplied(kindName(sym),
5328                         sym.name,
5329                         rs.methodArguments(sym.type.getParameterTypes()),
5330                         rs.methodArguments(argtypes.map(checkDeferredMap)),
5331                         kindName(sym.location()),
5332                         sym.location()));
5333                 if (resultInfo.pt != Infer.anyPoly ||
5334                         !owntype.hasTag(METHOD) ||
5335                         !owntype.isPartial()) {
5336                     //if this is not a partially inferred method type, erase return type. Otherwise,
5337                     //erasure is carried out in PartiallyInferredMethodType.check().
5338                     owntype = new MethodType(owntype.getParameterTypes(),
5339                             types.erasure(owntype.getReturnType()),
5340                             types.erasure(owntype.getThrownTypes()),
5341                             syms.methodClass);
5342                 }
5343             }
5344 
5345             PolyKind pkind = (sym.type.hasTag(FORALL) &&
5346                  sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
5347                  PolyKind.POLY : PolyKind.STANDALONE;
5348             TreeInfo.setPolyKind(env.tree, pkind);
5349 
5350             return (resultInfo.pt == Infer.anyPoly) ?
5351                     owntype :
5352                     chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
5353                             resultInfo.checkContext.inferenceContext());
5354         } catch (Infer.InferenceException ex) {
5355             //invalid target type - propagate exception outwards or report error
5356             //depending on the current check context
5357             resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
5358             return types.createErrorType(site);
5359         } catch (Resolve.InapplicableMethodException ex) {
5360             final JCDiagnostic diag = ex.getDiagnostic();
5361             Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
5362                 @Override
5363                 protected Pair<Symbol, JCDiagnostic> errCandidate() {
5364                     return new Pair<>(sym, diag);
5365                 }
5366             };
5367             List<Type> argtypes2 = argtypes.map(
5368                     rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
5369             JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
5370                     env.tree, sym, site, sym.name, argtypes2, typeargtypes);
5371             log.report(errDiag);
5372             return types.createErrorType(site);
5373         }
5374     }
5375 
5376     public void visitLiteral(JCLiteral tree) {
5377         result = check(tree, litType(tree.typetag).constType(tree.value),
5378                 KindSelector.VAL, resultInfo);
5379     }
5380     //where
5381     /** Return the type of a literal with given type tag.
5382      */
5383     Type litType(TypeTag tag) {
5384         return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
5385     }
5386 
5387     public void visitTypeIdent(JCPrimitiveTypeTree tree) {
5388         result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
5389     }
5390 
5391     public void visitTypeArray(JCArrayTypeTree tree) {
5392         Type etype = attribType(tree.elemtype, env);
5393         Type type = new ArrayType(etype, syms.arrayClass);
5394         result = check(tree, type, KindSelector.TYP, resultInfo);
5395     }
5396 
5397     /** Visitor method for parameterized types.
5398      *  Bound checking is left until later, since types are attributed
5399      *  before supertype structure is completely known
5400      */
5401     public void visitTypeApply(JCTypeApply tree) {
5402         Type owntype = types.createErrorType(tree.type);
5403 
5404         // Attribute functor part of application and make sure it's a class.
5405         Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
5406 
5407         // Attribute type parameters
5408         List<Type> actuals = attribTypes(tree.arguments, env);
5409 
5410         if (clazztype.hasTag(CLASS)) {
5411             List<Type> formals = clazztype.tsym.type.getTypeArguments();
5412             if (actuals.isEmpty()) //diamond
5413                 actuals = formals;
5414 
5415             if (actuals.length() == formals.length()) {
5416                 List<Type> a = actuals;
5417                 List<Type> f = formals;
5418                 while (a.nonEmpty()) {
5419                     a.head = a.head.withTypeVar(f.head);
5420                     a = a.tail;
5421                     f = f.tail;
5422                 }
5423                 // Compute the proper generic outer
5424                 Type clazzOuter = clazztype.getEnclosingType();
5425                 if (clazzOuter.hasTag(CLASS)) {
5426                     Type site;
5427                     JCExpression clazz = TreeInfo.typeIn(tree.clazz);
5428                     if (clazz.hasTag(IDENT)) {
5429                         site = env.enclClass.sym.type;
5430                     } else if (clazz.hasTag(SELECT)) {
5431                         site = ((JCFieldAccess) clazz).selected.type;
5432                     } else throw new AssertionError(""+tree);
5433                     if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
5434                         if (site.hasTag(CLASS) || site.hasTag(TYPEVAR))
5435                             site = types.asEnclosingSuper(site, clazzOuter.tsym);
5436                         if (site == null)
5437                             site = types.erasure(clazzOuter);
5438                         clazzOuter = site;
5439                     }
5440                 }
5441                 owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
5442                                         clazztype.getMetadata());
5443             } else {
5444                 if (formals.length() != 0) {
5445                     log.error(tree.pos(),
5446                               Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
5447                 } else {
5448                     log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
5449                 }
5450                 owntype = types.createErrorType(tree.type);
5451             }
5452         } else if (clazztype.hasTag(ERROR)) {
5453             ErrorType parameterizedErroneous =
5454                     new ErrorType(clazztype.getOriginalType(),
5455                                   clazztype.tsym,
5456                                   clazztype.getMetadata());
5457 
5458             parameterizedErroneous.typarams_field = actuals;
5459             owntype = parameterizedErroneous;
5460         }
5461         result = check(tree, owntype, KindSelector.TYP, resultInfo);
5462     }
5463 
5464     public void visitTypeUnion(JCTypeUnion tree) {
5465         ListBuffer<Type> multicatchTypes = new ListBuffer<>();
5466         ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
5467         for (JCExpression typeTree : tree.alternatives) {
5468             Type ctype = attribType(typeTree, env);
5469             ctype = chk.checkType(typeTree.pos(),
5470                           chk.checkClassType(typeTree.pos(), ctype),
5471                           syms.throwableType);
5472             if (!ctype.isErroneous()) {
5473                 //check that alternatives of a union type are pairwise
5474                 //unrelated w.r.t. subtyping
5475                 if (chk.intersects(ctype,  multicatchTypes.toList())) {
5476                     for (Type t : multicatchTypes) {
5477                         boolean sub = types.isSubtype(ctype, t);
5478                         boolean sup = types.isSubtype(t, ctype);
5479                         if (sub || sup) {
5480                             //assume 'a' <: 'b'
5481                             Type a = sub ? ctype : t;
5482                             Type b = sub ? t : ctype;
5483                             log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
5484                         }
5485                     }
5486                 }
5487                 multicatchTypes.append(ctype);
5488                 if (all_multicatchTypes != null)
5489                     all_multicatchTypes.append(ctype);
5490             } else {
5491                 if (all_multicatchTypes == null) {
5492                     all_multicatchTypes = new ListBuffer<>();
5493                     all_multicatchTypes.appendList(multicatchTypes);
5494                 }
5495                 all_multicatchTypes.append(ctype);
5496             }
5497         }
5498         Type t = check(tree, types.lub(multicatchTypes.toList()),
5499                 KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
5500         if (t.hasTag(CLASS)) {
5501             List<Type> alternatives =
5502                 ((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
5503             t = new UnionClassType((ClassType) t, alternatives);
5504         }
5505         tree.type = result = t;
5506     }
5507 
5508     public void visitTypeIntersection(JCTypeIntersection tree) {
5509         attribTypes(tree.bounds, env);
5510         tree.type = result = checkIntersection(tree, tree.bounds);
5511     }
5512 
5513     public void visitTypeParameter(JCTypeParameter tree) {
5514         TypeVar typeVar = (TypeVar) tree.type;
5515 
5516         if (tree.annotations != null && tree.annotations.nonEmpty()) {
5517             annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
5518         }
5519 
5520         if (!typeVar.getUpperBound().isErroneous()) {
5521             //fixup type-parameter bound computed in 'attribTypeVariables'
5522             typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
5523         }
5524     }
5525 
5526     Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
5527         Set<Symbol> boundSet = new HashSet<>();
5528         if (bounds.nonEmpty()) {
5529             // accept class or interface or typevar as first bound.
5530             bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
5531             boundSet.add(types.erasure(bounds.head.type).tsym);
5532             if (bounds.head.type.isErroneous()) {
5533                 return bounds.head.type;
5534             }
5535             else if (bounds.head.type.hasTag(TYPEVAR)) {
5536                 // if first bound was a typevar, do not accept further bounds.
5537                 if (bounds.tail.nonEmpty()) {
5538                     log.error(bounds.tail.head.pos(),
5539                               Errors.TypeVarMayNotBeFollowedByOtherBounds);
5540                     return bounds.head.type;
5541                 }
5542             } else {
5543                 // if first bound was a class or interface, accept only interfaces
5544                 // as further bounds.
5545                 for (JCExpression bound : bounds.tail) {
5546                     bound.type = checkBase(bound.type, bound, env, false, true, false);
5547                     if (bound.type.isErroneous()) {
5548                         bounds = List.of(bound);
5549                     }
5550                     else if (bound.type.hasTag(CLASS)) {
5551                         chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
5552                     }
5553                 }
5554             }
5555         }
5556 
5557         if (bounds.length() == 0) {
5558             return syms.objectType;
5559         } else if (bounds.length() == 1) {
5560             return bounds.head.type;
5561         } else {
5562             Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
5563             // ... the variable's bound is a class type flagged COMPOUND
5564             // (see comment for TypeVar.bound).
5565             // In this case, generate a class tree that represents the
5566             // bound class, ...
5567             JCExpression extending;
5568             List<JCExpression> implementing;
5569             if (!bounds.head.type.isInterface()) {
5570                 extending = bounds.head;
5571                 implementing = bounds.tail;
5572             } else {
5573                 extending = null;
5574                 implementing = bounds;
5575             }
5576             JCClassDecl cd = make.at(tree).ClassDef(
5577                 make.Modifiers(PUBLIC | ABSTRACT),
5578                 names.empty, List.nil(),
5579                 extending, implementing, List.nil());
5580 
5581             ClassSymbol c = (ClassSymbol)owntype.tsym;
5582             Assert.check((c.flags() & COMPOUND) != 0);
5583             cd.sym = c;
5584             c.sourcefile = env.toplevel.sourcefile;
5585 
5586             // ... and attribute the bound class
5587             c.flags_field |= UNATTRIBUTED;
5588             Env<AttrContext> cenv = enter.classEnv(cd, env);
5589             typeEnvs.put(c, cenv);
5590             attribClass(c);
5591             return owntype;
5592         }
5593     }
5594 
5595     public void visitWildcard(JCWildcard tree) {
5596         //- System.err.println("visitWildcard("+tree+");");//DEBUG
5597         Type type = (tree.kind.kind == BoundKind.UNBOUND)
5598             ? syms.objectType
5599             : attribType(tree.inner, env);
5600         result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
5601                                               tree.kind.kind,
5602                                               syms.boundClass),
5603                 KindSelector.TYP, resultInfo);
5604     }
5605 
5606     public void visitAnnotation(JCAnnotation tree) {
5607         Assert.error("should be handled in annotate");
5608     }
5609 
5610     @Override
5611     public void visitModifiers(JCModifiers tree) {
5612         //error recovery only:
5613         Assert.check(resultInfo.pkind == KindSelector.ERR);
5614 
5615         attribAnnotationTypes(tree.annotations, env);
5616     }
5617 
5618     public void visitAnnotatedType(JCAnnotatedType tree) {
5619         attribAnnotationTypes(tree.annotations, env);
5620         Type underlyingType = attribType(tree.underlyingType, env);
5621         Type annotatedType = underlyingType.preannotatedType();
5622 
5623         if (!env.info.isAnonymousNewClass)
5624             annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
5625         result = tree.type = annotatedType;
5626     }
5627 
5628     public void visitErroneous(JCErroneous tree) {
5629         if (tree.errs != null) {
5630             WriteableScope newScope = env.info.scope;
5631 
5632             if (env.tree instanceof JCClassDecl) {
5633                 Symbol fakeOwner =
5634                     new MethodSymbol(BLOCK, names.empty, null,
5635                         env.info.scope.owner);
5636                 newScope = newScope.dupUnshared(fakeOwner);
5637             }
5638 
5639             Env<AttrContext> errEnv =
5640                     env.dup(env.tree,
5641                             env.info.dup(newScope));
5642             errEnv.info.returnResult = unknownExprInfo;
5643             for (JCTree err : tree.errs)
5644                 attribTree(err, errEnv, new ResultInfo(KindSelector.ERR, pt()));
5645         }
5646         result = tree.type = syms.errType;
5647     }
5648 
5649     /** Default visitor method for all other trees.
5650      */
5651     public void visitTree(JCTree tree) {
5652         throw new AssertionError();
5653     }
5654 
5655     /**
5656      * Attribute an env for either a top level tree or class or module declaration.
5657      */
5658     public void attrib(Env<AttrContext> env) {
5659         switch (env.tree.getTag()) {
5660             case MODULEDEF:
5661                 attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
5662                 break;
5663             case PACKAGEDEF:
5664                 attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
5665                 break;
5666             default:
5667                 attribClass(env.tree.pos(), env.enclClass.sym);
5668         }
5669 
5670         annotate.flush();
5671 
5672         // Now that this tree is attributed, we can calculate the Lint configuration everywhere within it
5673         lintMapper.calculateLints(env.toplevel.sourcefile, env.tree, env.toplevel.endPositions);
5674     }
5675 
5676     public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
5677         try {
5678             annotate.flush();
5679             attribPackage(p);
5680         } catch (CompletionFailure ex) {
5681             chk.completionError(pos, ex);
5682         }
5683     }
5684 
5685     void attribPackage(PackageSymbol p) {
5686         attribWithLint(p,
5687                        env -> chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p));
5688     }
5689 
5690     public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
5691         try {
5692             annotate.flush();
5693             attribModule(m);
5694         } catch (CompletionFailure ex) {
5695             chk.completionError(pos, ex);
5696         }
5697     }
5698 
5699     void attribModule(ModuleSymbol m) {
5700         attribWithLint(m, env -> attribStat(env.tree, env));
5701     }
5702 
5703     private void attribWithLint(TypeSymbol sym, Consumer<Env<AttrContext>> attrib) {
5704         Env<AttrContext> env = typeEnvs.get(sym);
5705 
5706         Env<AttrContext> lintEnv = env;
5707         while (lintEnv.info.lint == null)
5708             lintEnv = lintEnv.next;
5709 
5710         Lint lint = lintEnv.info.lint.augment(sym);
5711 
5712         Lint prevLint = chk.setLint(lint);
5713         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
5714 
5715         try {
5716             attrib.accept(env);
5717         } finally {
5718             log.useSource(prev);
5719             chk.setLint(prevLint);
5720         }
5721     }
5722 
5723     /** Main method: attribute class definition associated with given class symbol.
5724      *  reporting completion failures at the given position.
5725      *  @param pos The source position at which completion errors are to be
5726      *             reported.
5727      *  @param c   The class symbol whose definition will be attributed.
5728      */
5729     public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
5730         try {
5731             annotate.flush();
5732             attribClass(c);
5733         } catch (CompletionFailure ex) {
5734             chk.completionError(pos, ex);
5735         }
5736     }
5737 
5738     /** Attribute class definition associated with given class symbol.
5739      *  @param c   The class symbol whose definition will be attributed.
5740      */
5741     void attribClass(ClassSymbol c) throws CompletionFailure {
5742         if (c.type.hasTag(ERROR)) return;
5743 
5744         // Check for cycles in the inheritance graph, which can arise from
5745         // ill-formed class files.
5746         chk.checkNonCyclic(null, c.type);
5747 
5748         Type st = types.supertype(c.type);
5749         if ((c.flags_field & Flags.COMPOUND) == 0 &&
5750             (c.flags_field & Flags.SUPER_OWNER_ATTRIBUTED) == 0) {
5751             // First, attribute superclass.
5752             if (st.hasTag(CLASS))
5753                 attribClass((ClassSymbol)st.tsym);
5754 
5755             // Next attribute owner, if it is a class.
5756             if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
5757                 attribClass((ClassSymbol)c.owner);
5758 
5759             c.flags_field |= Flags.SUPER_OWNER_ATTRIBUTED;
5760         }
5761 
5762         // The previous operations might have attributed the current class
5763         // if there was a cycle. So we test first whether the class is still
5764         // UNATTRIBUTED.
5765         if ((c.flags_field & UNATTRIBUTED) != 0) {
5766             c.flags_field &= ~UNATTRIBUTED;
5767 
5768             // Get environment current at the point of class definition.
5769             Env<AttrContext> env = typeEnvs.get(c);
5770 
5771             // The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
5772             // because the annotations were not available at the time the env was created. Therefore,
5773             // we look up the environment chain for the first enclosing environment for which the
5774             // lint value is set. Typically, this is the parent env, but might be further if there
5775             // are any envs created as a result of TypeParameter nodes.
5776             Env<AttrContext> lintEnv = env;
5777             while (lintEnv.info.lint == null)
5778                 lintEnv = lintEnv.next;
5779 
5780             // Having found the enclosing lint value, we can initialize the lint value for this class
5781             env.info.lint = lintEnv.info.lint.augment(c);
5782 
5783             Lint prevLint = chk.setLint(env.info.lint);
5784             JavaFileObject prev = log.useSource(c.sourcefile);
5785             ResultInfo prevReturnRes = env.info.returnResult;
5786 
5787             try {
5788                 if (c.isSealed() &&
5789                         !c.isEnum() &&
5790                         !c.isPermittedExplicit &&
5791                         c.getPermittedSubclasses().isEmpty()) {
5792                     log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.SealedClassMustHaveSubclasses);
5793                 }
5794 
5795                 if (c.isSealed()) {
5796                     Set<Symbol> permittedTypes = new HashSet<>();
5797                     boolean sealedInUnnamed = c.packge().modle == syms.unnamedModule || c.packge().modle == syms.noModule;
5798                     for (Type subType : c.getPermittedSubclasses()) {
5799                         if (subType.isErroneous()) {
5800                             // the type already caused errors, don't produce more potentially misleading errors
5801                             continue;
5802                         }
5803                         boolean isTypeVar = false;
5804                         if (subType.getTag() == TYPEVAR) {
5805                             isTypeVar = true; //error recovery
5806                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5807                                     Errors.InvalidPermitsClause(Fragments.IsATypeVariable(subType)));
5808                         }
5809                         if (subType.tsym.isAnonymous() && !c.isEnum()) {
5810                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),  Errors.LocalClassesCantExtendSealed(Fragments.Anonymous));
5811                         }
5812                         if (permittedTypes.contains(subType.tsym)) {
5813                             DiagnosticPosition pos =
5814                                     env.enclClass.permitting.stream()
5815                                             .filter(permittedExpr -> TreeInfo.diagnosticPositionFor(subType.tsym, permittedExpr, true) != null)
5816                                             .limit(2).collect(List.collector()).get(1);
5817                             log.error(pos, Errors.InvalidPermitsClause(Fragments.IsDuplicated(subType)));
5818                         } else {
5819                             permittedTypes.add(subType.tsym);
5820                         }
5821                         if (sealedInUnnamed) {
5822                             if (subType.tsym.packge() != c.packge()) {
5823                                 log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5824                                         Errors.ClassInUnnamedModuleCantExtendSealedInDiffPackage(c)
5825                                 );
5826                             }
5827                         } else if (subType.tsym.packge().modle != c.packge().modle) {
5828                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5829                                     Errors.ClassInModuleCantExtendSealedInDiffModule(c, c.packge().modle)
5830                             );
5831                         }
5832                         if (subType.tsym == c.type.tsym || types.isSuperType(subType, c.type)) {
5833                             log.error(TreeInfo.diagnosticPositionFor(subType.tsym, ((JCClassDecl)env.tree).permitting),
5834                                     Errors.InvalidPermitsClause(
5835                                             subType.tsym == c.type.tsym ?
5836                                                     Fragments.MustNotBeSameClass :
5837                                                     Fragments.MustNotBeSupertype(subType)
5838                                     )
5839                             );
5840                         } else if (!isTypeVar) {
5841                             boolean thisIsASuper = types.directSupertypes(subType)
5842                                                         .stream()
5843                                                         .anyMatch(d -> d.tsym == c);
5844                             if (!thisIsASuper) {
5845                                 if(c.isInterface()) {
5846                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5847                                             Errors.InvalidPermitsClause(Fragments.DoesntImplementSealed(kindName(subType.tsym), subType)));
5848                                 } else {
5849                                     log.error(TreeInfo.diagnosticPositionFor(subType.tsym, env.tree),
5850                                             Errors.InvalidPermitsClause(Fragments.DoesntExtendSealed(subType)));
5851                                 }
5852                             }
5853                         }
5854                     }
5855                 }
5856 
5857                 List<ClassSymbol> sealedSupers = types.directSupertypes(c.type)
5858                                                       .stream()
5859                                                       .filter(s -> s.tsym.isSealed())
5860                                                       .map(s -> (ClassSymbol) s.tsym)
5861                                                       .collect(List.collector());
5862 
5863                 if (sealedSupers.isEmpty()) {
5864                     if ((c.flags_field & Flags.NON_SEALED) != 0) {
5865                         boolean hasErrorSuper = false;
5866 
5867                         hasErrorSuper |= types.directSupertypes(c.type)
5868                                               .stream()
5869                                               .anyMatch(s -> s.tsym.kind == Kind.ERR);
5870 
5871                         ClassType ct = (ClassType) c.type;
5872 
5873                         hasErrorSuper |= !ct.isCompound() && ct.interfaces_field != ct.all_interfaces_field;
5874 
5875                         if (!hasErrorSuper) {
5876                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.NonSealedWithNoSealedSupertype(c));
5877                         }
5878                     }
5879                 } else if ((c.flags_field & Flags.COMPOUND) == 0) {
5880                     if (c.isDirectlyOrIndirectlyLocal() && !c.isEnum()) {
5881                         log.error(TreeInfo.diagnosticPositionFor(c, env.tree), Errors.LocalClassesCantExtendSealed(c.isAnonymous() ? Fragments.Anonymous : Fragments.Local));
5882                     }
5883 
5884                     if (!c.type.isCompound()) {
5885                         for (ClassSymbol supertypeSym : sealedSupers) {
5886                             if (!supertypeSym.isPermittedSubclass(c.type.tsym)) {
5887                                 log.error(TreeInfo.diagnosticPositionFor(c.type.tsym, env.tree), Errors.CantInheritFromSealed(supertypeSym));
5888                             }
5889                         }
5890                         if (!c.isNonSealed() && !c.isFinal() && !c.isSealed()) {
5891                             log.error(TreeInfo.diagnosticPositionFor(c, env.tree),
5892                                     c.isInterface() ?
5893                                             Errors.NonSealedOrSealedExpected :
5894                                             Errors.NonSealedSealedOrFinalExpected);
5895                         }
5896                     }
5897                 }
5898 
5899                 env.info.returnResult = null;
5900                 // java.lang.Enum may not be subclassed by a non-enum
5901                 if (st.tsym == syms.enumSym &&
5902                     ((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
5903                     log.error(env.tree.pos(), Errors.EnumNoSubclassing);
5904 
5905                 // Enums may not be extended by source-level classes
5906                 if (st.tsym != null &&
5907                     ((st.tsym.flags_field & Flags.ENUM) != 0) &&
5908                     ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
5909                     log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
5910                 }
5911 
5912                 if (rs.isSerializable(c.type)) {
5913                     env.info.isSerializable = true;
5914                 }
5915 
5916                 if (c.isValueClass()) {
5917                     Assert.check(env.tree.hasTag(CLASSDEF));
5918                     chk.checkConstraintsOfValueClass((JCClassDecl) env.tree, c);
5919                 }
5920 
5921                 attribClassBody(env, c);
5922 
5923                 chk.checkDeprecatedAnnotation(env.tree.pos(), c);
5924                 chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
5925                 chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
5926                 chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
5927 
5928                 if (c.isImplicit()) {
5929                     chk.checkHasMain(env.tree.pos(), c);
5930                 }
5931             } finally {
5932                 env.info.returnResult = prevReturnRes;
5933                 log.useSource(prev);
5934                 chk.setLint(prevLint);
5935             }
5936 
5937         }
5938     }
5939 
5940     public void visitImport(JCImport tree) {
5941         // nothing to do
5942     }
5943 
5944     public void visitModuleDef(JCModuleDecl tree) {
5945         tree.sym.completeUsesProvides();
5946         ModuleSymbol msym = tree.sym;
5947         Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
5948         Lint prevLint = chk.setLint(lint);
5949         try {
5950             chk.checkModuleName(tree);
5951             chk.checkDeprecatedAnnotation(tree, msym);
5952         } finally {
5953             chk.setLint(prevLint);
5954         }
5955     }
5956 
5957     /** Finish the attribution of a class. */
5958     private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
5959         JCClassDecl tree = (JCClassDecl)env.tree;
5960         Assert.check(c == tree.sym);
5961 
5962         // Validate type parameters, supertype and interfaces.
5963         attribStats(tree.typarams, env);
5964         if (!c.isAnonymous()) {
5965             //already checked if anonymous
5966             chk.validate(tree.typarams, env);
5967             chk.validate(tree.extending, env);
5968             chk.validate(tree.implementing, env);
5969         }
5970 
5971         chk.checkRequiresIdentity(tree, env.info.lint);
5972 
5973         c.markAbstractIfNeeded(types);
5974 
5975         // If this is a non-abstract class, check that it has no abstract
5976         // methods or unimplemented methods of an implemented interface.
5977         if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
5978             chk.checkAllDefined(tree.pos(), c);
5979         }
5980 
5981         if ((c.flags() & ANNOTATION) != 0) {
5982             if (tree.implementing.nonEmpty())
5983                 log.error(tree.implementing.head.pos(),
5984                           Errors.CantExtendIntfAnnotation);
5985             if (tree.typarams.nonEmpty()) {
5986                 log.error(tree.typarams.head.pos(),
5987                           Errors.IntfAnnotationCantHaveTypeParams(c));
5988             }
5989 
5990             // If this annotation type has a @Repeatable, validate
5991             Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
5992             // If this annotation type has a @Repeatable, validate
5993             if (repeatable != null) {
5994                 // get diagnostic position for error reporting
5995                 DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
5996                 Assert.checkNonNull(cbPos);
5997 
5998                 chk.validateRepeatable(c, repeatable, cbPos);
5999             }
6000         } else {
6001             // Check that all extended classes and interfaces
6002             // are compatible (i.e. no two define methods with same arguments
6003             // yet different return types).  (JLS 8.4.8.3)
6004             chk.checkCompatibleSupertypes(tree.pos(), c.type);
6005             chk.checkDefaultMethodClashes(tree.pos(), c.type);
6006             chk.checkPotentiallyAmbiguousOverloads(tree, c.type);
6007         }
6008 
6009         // Check that class does not import the same parameterized interface
6010         // with two different argument lists.
6011         chk.checkClassBounds(tree.pos(), c.type);
6012 
6013         tree.type = c.type;
6014 
6015         for (List<JCTypeParameter> l = tree.typarams;
6016              l.nonEmpty(); l = l.tail) {
6017              Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
6018         }
6019 
6020         // Check that a generic class doesn't extend Throwable
6021         if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
6022             log.error(tree.extending.pos(), Errors.GenericThrowable);
6023 
6024         // Check that all methods which implement some
6025         // method conform to the method they implement.
6026         chk.checkImplementations(tree);
6027 
6028         //check that a resource implementing AutoCloseable cannot throw InterruptedException
6029         checkAutoCloseable(tree.pos(), env, c.type);
6030 
6031         for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
6032             // Attribute declaration
6033             attribStat(l.head, env);
6034             // Check that declarations in inner classes are not static (JLS 8.1.2)
6035             // Make an exception for static constants.
6036             if (!allowRecords &&
6037                     c.owner.kind != PCK &&
6038                     ((c.flags() & STATIC) == 0 || c.name == names.empty) &&
6039                     (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
6040                 VarSymbol sym = null;
6041                 if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
6042                 if (sym == null ||
6043                         sym.kind != VAR ||
6044                         sym.getConstValue() == null)
6045                     log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
6046             }
6047         }
6048 
6049         // Check for proper placement of super()/this() calls.
6050         chk.checkSuperInitCalls(tree);
6051 
6052         // Check for cycles among non-initial constructors.
6053         chk.checkCyclicConstructors(tree);
6054 
6055         // Check for cycles among annotation elements.
6056         chk.checkNonCyclicElements(tree);
6057 
6058         // Check for proper use of serialVersionUID and other
6059         // serialization-related fields and methods
6060         if (env.info.lint.isEnabled(LintCategory.SERIAL)
6061                 && rs.isSerializable(c.type)
6062                 && !c.isAnonymous()) {
6063             chk.checkSerialStructure(env, tree, c);
6064         }
6065         // Correctly organize the positions of the type annotations
6066         typeAnnotations.organizeTypeAnnotationsBodies(tree);
6067 
6068         // Check type annotations applicability rules
6069         validateTypeAnnotations(tree, false);
6070     }
6071         // where
6072         /** get a diagnostic position for an attribute of Type t, or null if attribute missing */
6073         private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
6074             for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
6075                 if (types.isSameType(al.head.annotationType.type, t))
6076                     return al.head.pos();
6077             }
6078 
6079             return null;
6080         }
6081 
6082     private Type capture(Type type) {
6083         return types.capture(type);
6084     }
6085 
6086     private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
6087         if (type.isErroneous()) {
6088             tree.vartype = make.at(tree.pos()).Erroneous();
6089         } else if (tree.declaredUsingVar()) {
6090             Assert.check(tree.typePos != Position.NOPOS);
6091             tree.vartype = make.at(tree.typePos).Type(type);
6092         } else {
6093             tree.vartype = make.at(tree.pos()).Type(type);
6094         }
6095     }
6096 
6097     public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
6098         tree.accept(new TypeAnnotationsValidator(sigOnly));
6099     }
6100     //where
6101     private final class TypeAnnotationsValidator extends TreeScanner {
6102 
6103         private final boolean sigOnly;
6104         public TypeAnnotationsValidator(boolean sigOnly) {
6105             this.sigOnly = sigOnly;
6106         }
6107 
6108         public void visitAnnotation(JCAnnotation tree) {
6109             chk.validateTypeAnnotation(tree, null, false);
6110             super.visitAnnotation(tree);
6111         }
6112         public void visitAnnotatedType(JCAnnotatedType tree) {
6113             if (!tree.underlyingType.type.isErroneous()) {
6114                 super.visitAnnotatedType(tree);
6115             }
6116         }
6117         public void visitTypeParameter(JCTypeParameter tree) {
6118             chk.validateTypeAnnotations(tree.annotations, tree.type.tsym, true);
6119             scan(tree.bounds);
6120             // Don't call super.
6121             // This is needed because above we call validateTypeAnnotation with
6122             // false, which would forbid annotations on type parameters.
6123             // super.visitTypeParameter(tree);
6124         }
6125         public void visitMethodDef(JCMethodDecl tree) {
6126             if (tree.recvparam != null &&
6127                     !tree.recvparam.vartype.type.isErroneous()) {
6128                 checkForDeclarationAnnotations(tree.recvparam.mods.annotations, tree.recvparam.sym);
6129             }
6130             if (tree.restype != null && tree.restype.type != null) {
6131                 validateAnnotatedType(tree.restype, tree.restype.type);
6132             }
6133             if (sigOnly) {
6134                 scan(tree.mods);
6135                 scan(tree.restype);
6136                 scan(tree.typarams);
6137                 scan(tree.recvparam);
6138                 scan(tree.params);
6139                 scan(tree.thrown);
6140             } else {
6141                 scan(tree.defaultValue);
6142                 scan(tree.body);
6143             }
6144         }
6145         public void visitVarDef(final JCVariableDecl tree) {
6146             //System.err.println("validateTypeAnnotations.visitVarDef " + tree);
6147             if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
6148                 validateAnnotatedType(tree.vartype, tree.sym.type);
6149             scan(tree.mods);
6150             scan(tree.vartype);
6151             if (!sigOnly) {
6152                 scan(tree.init);
6153             }
6154         }
6155         public void visitTypeCast(JCTypeCast tree) {
6156             if (tree.clazz != null && tree.clazz.type != null)
6157                 validateAnnotatedType(tree.clazz, tree.clazz.type);
6158             super.visitTypeCast(tree);
6159         }
6160         public void visitTypeTest(JCInstanceOf tree) {
6161             if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
6162                 validateAnnotatedType(tree.pattern, tree.pattern.type);
6163             super.visitTypeTest(tree);
6164         }
6165         public void visitNewClass(JCNewClass tree) {
6166             if (tree.clazz != null && tree.clazz.type != null) {
6167                 if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
6168                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
6169                             tree.clazz.type.tsym);
6170                 }
6171                 if (tree.def != null) {
6172                     checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
6173                 }
6174 
6175                 validateAnnotatedType(tree.clazz, tree.clazz.type);
6176             }
6177             super.visitNewClass(tree);
6178         }
6179         public void visitNewArray(JCNewArray tree) {
6180             if (tree.elemtype != null && tree.elemtype.type != null) {
6181                 if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
6182                     checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
6183                             tree.elemtype.type.tsym);
6184                 }
6185                 validateAnnotatedType(tree.elemtype, tree.elemtype.type);
6186             }
6187             super.visitNewArray(tree);
6188         }
6189         public void visitClassDef(JCClassDecl tree) {
6190             //System.err.println("validateTypeAnnotations.visitClassDef " + tree);
6191             if (sigOnly) {
6192                 scan(tree.mods);
6193                 scan(tree.typarams);
6194                 scan(tree.extending);
6195                 scan(tree.implementing);
6196             }
6197             for (JCTree member : tree.defs) {
6198                 if (member.hasTag(Tag.CLASSDEF)) {
6199                     continue;
6200                 }
6201                 scan(member);
6202             }
6203         }
6204         public void visitBlock(JCBlock tree) {
6205             if (!sigOnly) {
6206                 scan(tree.stats);
6207             }
6208         }
6209 
6210         /* I would want to model this after
6211          * com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
6212          * and override visitSelect and visitTypeApply.
6213          * However, we only set the annotated type in the top-level type
6214          * of the symbol.
6215          * Therefore, we need to override each individual location where a type
6216          * can occur.
6217          */
6218         private void validateAnnotatedType(final JCTree errtree, final Type type) {
6219             //System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
6220 
6221             if (type.isPrimitiveOrVoid()) {
6222                 return;
6223             }
6224 
6225             JCTree enclTr = errtree;
6226             Type enclTy = type;
6227 
6228             boolean repeat = true;
6229             while (repeat) {
6230                 if (enclTr.hasTag(TYPEAPPLY)) {
6231                     List<Type> tyargs = enclTy.getTypeArguments();
6232                     List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
6233                     if (trargs.length() > 0) {
6234                         // Nothing to do for diamonds
6235                         if (tyargs.length() == trargs.length()) {
6236                             for (int i = 0; i < tyargs.length(); ++i) {
6237                                 validateAnnotatedType(trargs.get(i), tyargs.get(i));
6238                             }
6239                         }
6240                         // If the lengths don't match, it's either a diamond
6241                         // or some nested type that redundantly provides
6242                         // type arguments in the tree.
6243                     }
6244 
6245                     // Look at the clazz part of a generic type
6246                     enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
6247                 }
6248 
6249                 if (enclTr.hasTag(SELECT)) {
6250                     enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
6251                     if (enclTy != null &&
6252                             !enclTy.hasTag(NONE)) {
6253                         enclTy = enclTy.getEnclosingType();
6254                     }
6255                 } else if (enclTr.hasTag(ANNOTATED_TYPE)) {
6256                     JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
6257                     if (enclTy == null || enclTy.hasTag(NONE)) {
6258                         ListBuffer<Attribute.TypeCompound> onlyTypeAnnotationsBuf = new ListBuffer<>();
6259                         for (JCAnnotation an : at.getAnnotations()) {
6260                             if (chk.isTypeAnnotation(an, false)) {
6261                                 onlyTypeAnnotationsBuf.add((Attribute.TypeCompound) an.attribute);
6262                             }
6263                         }
6264                         List<Attribute.TypeCompound> onlyTypeAnnotations = onlyTypeAnnotationsBuf.toList();
6265                         if (!onlyTypeAnnotations.isEmpty()) {
6266                             Fragment annotationFragment = onlyTypeAnnotations.size() == 1 ?
6267                                     Fragments.TypeAnnotation1(onlyTypeAnnotations.head) :
6268                                     Fragments.TypeAnnotation(onlyTypeAnnotations);
6269                             JCDiagnostic.AnnotatedType annotatedType = new JCDiagnostic.AnnotatedType(
6270                                     type.stripMetadata().annotatedType(onlyTypeAnnotations));
6271                             log.error(at.underlyingType.pos(), Errors.TypeAnnotationInadmissible(annotationFragment,
6272                                     type.tsym.owner, annotatedType));
6273                         }
6274                         repeat = false;
6275                     }
6276                     enclTr = at.underlyingType;
6277                     // enclTy doesn't need to be changed
6278                 } else if (enclTr.hasTag(IDENT)) {
6279                     repeat = false;
6280                 } else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
6281                     JCWildcard wc = (JCWildcard) enclTr;
6282                     if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
6283                             wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
6284                         validateAnnotatedType(wc.getBound(), wc.getBound().type);
6285                     } else {
6286                         // Nothing to do for UNBOUND
6287                     }
6288                     repeat = false;
6289                 } else if (enclTr.hasTag(TYPEARRAY)) {
6290                     JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
6291                     validateAnnotatedType(art.getType(), art.elemtype.type);
6292                     repeat = false;
6293                 } else if (enclTr.hasTag(TYPEUNION)) {
6294                     JCTypeUnion ut = (JCTypeUnion) enclTr;
6295                     for (JCTree t : ut.getTypeAlternatives()) {
6296                         validateAnnotatedType(t, t.type);
6297                     }
6298                     repeat = false;
6299                 } else if (enclTr.hasTag(TYPEINTERSECTION)) {
6300                     JCTypeIntersection it = (JCTypeIntersection) enclTr;
6301                     for (JCTree t : it.getBounds()) {
6302                         validateAnnotatedType(t, t.type);
6303                     }
6304                     repeat = false;
6305                 } else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
6306                            enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
6307                     repeat = false;
6308                 } else {
6309                     Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
6310                             " within: "+ errtree + " with kind: " + errtree.getKind());
6311                 }
6312             }
6313         }
6314 
6315         private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
6316                 Symbol sym) {
6317             // Ensure that no declaration annotations are present.
6318             // Note that a tree type might be an AnnotatedType with
6319             // empty annotations, if only declaration annotations were given.
6320             // This method will raise an error for such a type.
6321             for (JCAnnotation ai : annotations) {
6322                 if (!ai.type.isErroneous() &&
6323                         typeAnnotations.annotationTargetType(ai, ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
6324                     log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
6325                 }
6326             }
6327         }
6328     }
6329 
6330     // <editor-fold desc="post-attribution visitor">
6331 
6332     /**
6333      * Handle missing types/symbols in an AST. This routine is useful when
6334      * the compiler has encountered some errors (which might have ended up
6335      * terminating attribution abruptly); if the compiler is used in fail-over
6336      * mode (e.g. by an IDE) and the AST contains semantic errors, this routine
6337      * prevents NPE to be propagated during subsequent compilation steps.
6338      */
6339     public void postAttr(JCTree tree) {
6340         new PostAttrAnalyzer().scan(tree);
6341     }
6342 
6343     class PostAttrAnalyzer extends TreeScanner {
6344 
6345         private void initTypeIfNeeded(JCTree that) {
6346             if (that.type == null) {
6347                 if (that.hasTag(METHODDEF)) {
6348                     that.type = dummyMethodType((JCMethodDecl)that);
6349                 } else {
6350                     that.type = syms.unknownType;
6351                 }
6352             }
6353         }
6354 
6355         /* Construct a dummy method type. If we have a method declaration,
6356          * and the declared return type is void, then use that return type
6357          * instead of UNKNOWN to avoid spurious error messages in lambda
6358          * bodies (see:JDK-8041704).
6359          */
6360         private Type dummyMethodType(JCMethodDecl md) {
6361             Type restype = syms.unknownType;
6362             if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
6363                 JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
6364                 if (prim.typetag == VOID)
6365                     restype = syms.voidType;
6366             }
6367             return new MethodType(List.nil(), restype,
6368                                   List.nil(), syms.methodClass);
6369         }
6370         private Type dummyMethodType() {
6371             return dummyMethodType(null);
6372         }
6373 
6374         @Override
6375         public void scan(JCTree tree) {
6376             if (tree == null) return;
6377             if (tree instanceof JCExpression) {
6378                 initTypeIfNeeded(tree);
6379             }
6380             super.scan(tree);
6381         }
6382 
6383         @Override
6384         public void visitIdent(JCIdent that) {
6385             if (that.sym == null) {
6386                 that.sym = syms.unknownSymbol;
6387             }
6388         }
6389 
6390         @Override
6391         public void visitSelect(JCFieldAccess that) {
6392             if (that.sym == null) {
6393                 that.sym = syms.unknownSymbol;
6394             }
6395             super.visitSelect(that);
6396         }
6397 
6398         @Override
6399         public void visitClassDef(JCClassDecl that) {
6400             initTypeIfNeeded(that);
6401             if (that.sym == null) {
6402                 that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
6403             }
6404             super.visitClassDef(that);
6405         }
6406 
6407         @Override
6408         public void visitMethodDef(JCMethodDecl that) {
6409             initTypeIfNeeded(that);
6410             if (that.sym == null) {
6411                 that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
6412             }
6413             super.visitMethodDef(that);
6414         }
6415 
6416         @Override
6417         public void visitVarDef(JCVariableDecl that) {
6418             initTypeIfNeeded(that);
6419             if (that.sym == null) {
6420                 that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
6421                 that.sym.adr = 0;
6422             }
6423             if (that.vartype == null) {
6424                 that.vartype = make.at(Position.NOPOS).Erroneous();
6425             }
6426             super.visitVarDef(that);
6427         }
6428 
6429         @Override
6430         public void visitBindingPattern(JCBindingPattern that) {
6431             initTypeIfNeeded(that);
6432             initTypeIfNeeded(that.var);
6433             if (that.var.sym == null) {
6434                 that.var.sym = new BindingSymbol(0, that.var.name, that.var.type, syms.noSymbol);
6435                 that.var.sym.adr = 0;
6436             }
6437             super.visitBindingPattern(that);
6438         }
6439 
6440         @Override
6441         public void visitRecordPattern(JCRecordPattern that) {
6442             initTypeIfNeeded(that);
6443             if (that.record == null) {
6444                 that.record = new ClassSymbol(0, TreeInfo.name(that.deconstructor),
6445                                               that.type, syms.noSymbol);
6446             }
6447             if (that.fullComponentTypes == null) {
6448                 that.fullComponentTypes = List.nil();
6449             }
6450             super.visitRecordPattern(that);
6451         }
6452 
6453         @Override
6454         public void visitNewClass(JCNewClass that) {
6455             if (that.constructor == null) {
6456                 that.constructor = new MethodSymbol(0, names.init,
6457                         dummyMethodType(), syms.noSymbol);
6458             }
6459             if (that.constructorType == null) {
6460                 that.constructorType = syms.unknownType;
6461             }
6462             super.visitNewClass(that);
6463         }
6464 
6465         @Override
6466         public void visitAssignop(JCAssignOp that) {
6467             if (that.operator == null) {
6468                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6469                         -1, syms.noSymbol);
6470             }
6471             super.visitAssignop(that);
6472         }
6473 
6474         @Override
6475         public void visitBinary(JCBinary that) {
6476             if (that.operator == null) {
6477                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6478                         -1, syms.noSymbol);
6479             }
6480             super.visitBinary(that);
6481         }
6482 
6483         @Override
6484         public void visitUnary(JCUnary that) {
6485             if (that.operator == null) {
6486                 that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
6487                         -1, syms.noSymbol);
6488             }
6489             super.visitUnary(that);
6490         }
6491 
6492         @Override
6493         public void visitReference(JCMemberReference that) {
6494             super.visitReference(that);
6495             if (that.sym == null) {
6496                 that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
6497                         syms.noSymbol);
6498             }
6499         }
6500     }
6501     // </editor-fold>
6502 
6503     public void setPackageSymbols(JCExpression pid, Symbol pkg) {
6504         new TreeScanner() {
6505             Symbol packge = pkg;
6506             @Override
6507             public void visitIdent(JCIdent that) {
6508                 that.sym = packge;
6509             }
6510 
6511             @Override
6512             public void visitSelect(JCFieldAccess that) {
6513                 that.sym = packge;
6514                 packge = packge.owner;
6515                 super.visitSelect(that);
6516             }
6517         }.scan(pid);
6518     }
6519 
6520 }