1 /*
   2  * Copyright (c) 1999, 2021, 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.tree;
  27 
  28 import java.util.Iterator;
  29 
  30 import com.sun.source.tree.CaseTree;
  31 import com.sun.source.tree.ModuleTree.ModuleKind;
  32 import com.sun.tools.javac.code.*;
  33 import com.sun.tools.javac.code.Attribute.UnresolvedClass;
  34 import com.sun.tools.javac.code.Symbol.*;
  35 import com.sun.tools.javac.code.Type.*;
  36 import com.sun.tools.javac.util.*;
  37 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  38 
  39 import com.sun.tools.javac.tree.JCTree.*;
  40 
  41 import static com.sun.tools.javac.code.Flags.*;
  42 import static com.sun.tools.javac.code.Kinds.Kind.*;
  43 import static com.sun.tools.javac.code.TypeTag.*;
  44 
  45 /** Factory class for trees.
  46  *
  47  *  <p><b>This is NOT part of any supported API.
  48  *  If you write code that depends on this, you do so at your own risk.
  49  *  This code and its internal interfaces are subject to change or
  50  *  deletion without notice.</b>
  51  */
  52 public class TreeMaker implements JCTree.Factory {
  53 
  54     /** The context key for the tree factory. */
  55     protected static final Context.Key<TreeMaker> treeMakerKey = new Context.Key<>();
  56 
  57     /** Get the TreeMaker instance. */
  58     public static TreeMaker instance(Context context) {
  59         TreeMaker instance = context.get(treeMakerKey);
  60         if (instance == null)
  61             instance = new TreeMaker(context);
  62         return instance;
  63     }
  64 
  65     /** The position at which subsequent trees will be created.
  66      */
  67     public int pos = Position.NOPOS;
  68 
  69     /** The toplevel tree to which created trees belong.
  70      */
  71     public JCCompilationUnit toplevel;
  72 
  73     /** The current name table. */
  74     Names names;
  75 
  76     Types types;
  77 
  78     /** The current symbol table. */
  79     Symtab syms;
  80 
  81     /** Create a tree maker with null toplevel and NOPOS as initial position.
  82      */
  83     protected TreeMaker(Context context) {
  84         context.put(treeMakerKey, this);
  85         this.pos = Position.NOPOS;
  86         this.toplevel = null;
  87         this.names = Names.instance(context);
  88         this.syms = Symtab.instance(context);
  89         this.types = Types.instance(context);
  90     }
  91 
  92     /** Create a tree maker with a given toplevel and FIRSTPOS as initial position.
  93      */
  94     protected TreeMaker(JCCompilationUnit toplevel, Names names, Types types, Symtab syms) {
  95         this.pos = Position.FIRSTPOS;
  96         this.toplevel = toplevel;
  97         this.names = names;
  98         this.types = types;
  99         this.syms = syms;
 100     }
 101 
 102     /** Create a new tree maker for a given toplevel.
 103      */
 104     public TreeMaker forToplevel(JCCompilationUnit toplevel) {
 105         return new TreeMaker(toplevel, names, types, syms);
 106     }
 107 
 108     /** Reassign current position.
 109      */
 110     public TreeMaker at(int pos) {
 111         this.pos = pos;
 112         return this;
 113     }
 114 
 115     /** Reassign current position.
 116      */
 117     public TreeMaker at(DiagnosticPosition pos) {
 118         this.pos = (pos == null ? Position.NOPOS : pos.getStartPosition());
 119         return this;
 120     }
 121 
 122     /**
 123      * Create given tree node at current position.
 124      * @param defs a list of PackageDef, ClassDef, Import, and Skip
 125      */
 126     public JCCompilationUnit TopLevel(List<JCTree> defs) {
 127         for (JCTree node : defs)
 128             Assert.check(node instanceof JCClassDecl
 129                 || node instanceof JCPackageDecl
 130                 || node instanceof JCImport
 131                 || node instanceof JCModuleDecl
 132                 || node instanceof JCSkip
 133                 || node instanceof JCErroneous
 134                 || (node instanceof JCExpressionStatement expressionStatement
 135                     && expressionStatement.expr instanceof JCErroneous),
 136                     () -> node.getClass().getSimpleName());
 137         JCCompilationUnit tree = new JCCompilationUnit(defs);
 138         tree.pos = pos;
 139         return tree;
 140     }
 141 
 142     public JCPackageDecl PackageDecl(List<JCAnnotation> annotations,
 143                                      JCExpression pid) {
 144         Assert.checkNonNull(annotations);
 145         Assert.checkNonNull(pid);
 146         JCPackageDecl tree = new JCPackageDecl(annotations, pid);
 147         tree.pos = pos;
 148         return tree;
 149     }
 150 
 151     public JCImport Import(JCTree qualid, boolean importStatic) {
 152         JCImport tree = new JCImport(qualid, importStatic);
 153         tree.pos = pos;
 154         return tree;
 155     }
 156 
 157     public JCClassDecl ClassDef(JCModifiers mods,
 158                                 Name name,
 159                                 List<JCTypeParameter> typarams,
 160                                 JCExpression extending,
 161                                 List<JCExpression> implementing,
 162                                 List<JCTree> defs)
 163     {
 164         return ClassDef(mods, name, typarams, extending, implementing, List.nil(), defs);
 165     }
 166 
 167     public JCClassDecl ClassDef(JCModifiers mods,
 168                                 Name name,
 169                                 List<JCTypeParameter> typarams,
 170                                 JCExpression extending,
 171                                 List<JCExpression> implementing,
 172                                 List<JCExpression> permitting,
 173                                 List<JCTree> defs)
 174     {
 175         JCClassDecl tree = new JCClassDecl(mods,
 176                                      name,
 177                                      typarams,
 178                                      extending,
 179                                      implementing,
 180                                      permitting,
 181                                      defs,
 182                                      null);
 183         tree.pos = pos;
 184         return tree;
 185     }
 186 
 187     public JCMethodDecl MethodDef(JCModifiers mods,
 188                                Name name,
 189                                JCExpression restype,
 190                                List<JCTypeParameter> typarams,
 191                                List<JCVariableDecl> params,
 192                                List<JCExpression> thrown,
 193                                JCBlock body,
 194                                JCExpression defaultValue) {
 195         return MethodDef(
 196                 mods, name, restype, typarams, null, params,
 197                 thrown, body, defaultValue);
 198     }
 199 
 200     public JCMethodDecl MethodDef(JCModifiers mods,
 201                                Name name,
 202                                JCExpression restype,
 203                                List<JCTypeParameter> typarams,
 204                                JCVariableDecl recvparam,
 205                                List<JCVariableDecl> params,
 206                                List<JCExpression> thrown,
 207                                JCBlock body,
 208                                JCExpression defaultValue)
 209     {
 210         JCMethodDecl tree = new JCMethodDecl(mods,
 211                                        name,
 212                                        restype,
 213                                        typarams,
 214                                        recvparam,
 215                                        params,
 216                                        thrown,
 217                                        body,
 218                                        defaultValue,
 219                                        null);
 220         tree.pos = pos;
 221         return tree;
 222     }
 223 
 224     public JCVariableDecl VarDef(JCModifiers mods, Name name, JCExpression vartype, JCExpression init) {
 225         JCVariableDecl tree = new JCVariableDecl(mods, name, vartype, init, null);
 226         tree.pos = pos;
 227         return tree;
 228     }
 229 
 230     public JCVariableDecl VarDef(JCModifiers mods, Name name, JCExpression vartype, JCExpression init, boolean declaredUsingVar) {
 231         JCVariableDecl tree = new JCVariableDecl(mods, name, vartype, init, null, declaredUsingVar);
 232         tree.pos = pos;
 233         return tree;
 234     }
 235 
 236     public JCVariableDecl ReceiverVarDef(JCModifiers mods, JCExpression name, JCExpression vartype) {
 237         JCVariableDecl tree = new JCVariableDecl(mods, name, vartype);
 238         tree.pos = pos;
 239         return tree;
 240     }
 241 
 242     public JCSkip Skip() {
 243         JCSkip tree = new JCSkip();
 244         tree.pos = pos;
 245         return tree;
 246     }
 247 
 248     public JCBlock Block(long flags, List<JCStatement> stats) {
 249         JCBlock tree = new JCBlock(flags, stats);
 250         tree.pos = pos;
 251         return tree;
 252     }
 253 
 254     public JCDoWhileLoop DoLoop(JCStatement body, JCExpression cond) {
 255         JCDoWhileLoop tree = new JCDoWhileLoop(body, cond);
 256         tree.pos = pos;
 257         return tree;
 258     }
 259 
 260     public JCWhileLoop WhileLoop(JCExpression cond, JCStatement body) {
 261         JCWhileLoop tree = new JCWhileLoop(cond, body);
 262         tree.pos = pos;
 263         return tree;
 264     }
 265 
 266     public JCForLoop ForLoop(List<JCStatement> init,
 267                            JCExpression cond,
 268                            List<JCExpressionStatement> step,
 269                            JCStatement body)
 270     {
 271         JCForLoop tree = new JCForLoop(init, cond, step, body);
 272         tree.pos = pos;
 273         return tree;
 274     }
 275 
 276     public JCEnhancedForLoop ForeachLoop(JCVariableDecl var, JCExpression expr, JCStatement body) {
 277         JCEnhancedForLoop tree = new JCEnhancedForLoop(var, expr, body);
 278         tree.pos = pos;
 279         return tree;
 280     }
 281 
 282     public JCLabeledStatement Labelled(Name label, JCStatement body) {
 283         JCLabeledStatement tree = new JCLabeledStatement(label, body);
 284         tree.pos = pos;
 285         return tree;
 286     }
 287 
 288     public JCSwitch Switch(JCExpression selector, List<JCCase> cases) {
 289         JCSwitch tree = new JCSwitch(selector, cases);
 290         tree.pos = pos;
 291         return tree;
 292     }
 293 
 294     public JCCase Case(CaseTree.CaseKind caseKind, List<JCCaseLabel> labels,
 295                        List<JCStatement> stats, JCTree body) {
 296         JCCase tree = new JCCase(caseKind, labels, stats, body);
 297         tree.pos = pos;
 298         return tree;
 299     }
 300 
 301     public JCSwitchExpression SwitchExpression(JCExpression selector, List<JCCase> cases) {
 302         JCSwitchExpression tree = new JCSwitchExpression(selector, cases);
 303         tree.pos = pos;
 304         return tree;
 305     }
 306 
 307     public JCSynchronized Synchronized(JCExpression lock, JCBlock body) {
 308         JCSynchronized tree = new JCSynchronized(lock, body);
 309         tree.pos = pos;
 310         return tree;
 311     }
 312 
 313     public JCTry Try(JCBlock body, List<JCCatch> catchers, JCBlock finalizer) {
 314         return Try(List.nil(), body, catchers, finalizer);
 315     }
 316 
 317     public JCTry Try(List<JCTree> resources,
 318                      JCBlock body,
 319                      List<JCCatch> catchers,
 320                      JCBlock finalizer) {
 321         JCTry tree = new JCTry(resources, body, catchers, finalizer);
 322         tree.pos = pos;
 323         return tree;
 324     }
 325 
 326     public JCCatch Catch(JCVariableDecl param, JCBlock body) {
 327         JCCatch tree = new JCCatch(param, body);
 328         tree.pos = pos;
 329         return tree;
 330     }
 331 
 332     public JCConditional Conditional(JCExpression cond,
 333                                    JCExpression thenpart,
 334                                    JCExpression elsepart)
 335     {
 336         JCConditional tree = new JCConditional(cond, thenpart, elsepart);
 337         tree.pos = pos;
 338         return tree;
 339     }
 340 
 341     public JCIf If(JCExpression cond, JCStatement thenpart, JCStatement elsepart) {
 342         JCIf tree = new JCIf(cond, thenpart, elsepart);
 343         tree.pos = pos;
 344         return tree;
 345     }
 346 
 347     public JCExpressionStatement Exec(JCExpression expr) {
 348         JCExpressionStatement tree = new JCExpressionStatement(expr);
 349         tree.pos = pos;
 350         return tree;
 351     }
 352 
 353     public JCBreak Break(Name label) {
 354         JCBreak tree = new JCBreak(label, null);
 355         tree.pos = pos;
 356         return tree;
 357     }
 358 
 359     public JCYield Yield(JCExpression value) {
 360         JCYield tree = new JCYield(value, null);
 361         tree.pos = pos;
 362         return tree;
 363     }
 364 
 365     public JCContinue Continue(Name label) {
 366         JCContinue tree = new JCContinue(label, null);
 367         tree.pos = pos;
 368         return tree;
 369     }
 370 
 371     public JCReturn Return(JCExpression expr) {
 372         JCReturn tree = new JCReturn(expr);
 373         tree.pos = pos;
 374         return tree;
 375     }
 376 
 377     public JCThrow Throw(JCExpression expr) {
 378         JCThrow tree = new JCThrow(expr);
 379         tree.pos = pos;
 380         return tree;
 381     }
 382 
 383     public JCAssert Assert(JCExpression cond, JCExpression detail) {
 384         JCAssert tree = new JCAssert(cond, detail);
 385         tree.pos = pos;
 386         return tree;
 387     }
 388 
 389     public JCMethodInvocation Apply(List<JCExpression> typeargs,
 390                        JCExpression fn,
 391                        List<JCExpression> args)
 392     {
 393         JCMethodInvocation tree = new JCMethodInvocation(typeargs, fn, args);
 394         tree.pos = pos;
 395         return tree;
 396     }
 397 
 398     public JCNewClass NewClass(JCExpression encl,
 399                              List<JCExpression> typeargs,
 400                              JCExpression clazz,
 401                              List<JCExpression> args,
 402                              JCClassDecl def)
 403     {
 404         return SpeculativeNewClass(encl, typeargs, clazz, args, def, false);
 405     }
 406 
 407     public JCNewClass SpeculativeNewClass(JCExpression encl,
 408                              List<JCExpression> typeargs,
 409                              JCExpression clazz,
 410                              List<JCExpression> args,
 411                              JCClassDecl def,
 412                              boolean classDefRemoved)
 413     {
 414         JCNewClass tree = classDefRemoved ?
 415                 new JCNewClass(encl, typeargs, clazz, args, def) {
 416                     @Override
 417                     public boolean classDeclRemoved() {
 418                         return true;
 419                     }
 420                 } :
 421                 new JCNewClass(encl, typeargs, clazz, args, def);
 422         tree.pos = pos;
 423         return tree;
 424     }
 425 
 426     public JCNewArray NewArray(JCExpression elemtype,
 427                              List<JCExpression> dims,
 428                              List<JCExpression> elems)
 429     {
 430         JCNewArray tree = new JCNewArray(elemtype, dims, elems);
 431         tree.pos = pos;
 432         return tree;
 433     }
 434 
 435     public JCLambda Lambda(List<JCVariableDecl> params,
 436                            JCTree body)
 437     {
 438         JCLambda tree = new JCLambda(params, body);
 439         tree.pos = pos;
 440         return tree;
 441     }
 442 
 443     public JCParens Parens(JCExpression expr) {
 444         JCParens tree = new JCParens(expr);
 445         tree.pos = pos;
 446         return tree;
 447     }
 448 
 449     public JCAssign Assign(JCExpression lhs, JCExpression rhs) {
 450         JCAssign tree = new JCAssign(lhs, rhs);
 451         tree.pos = pos;
 452         return tree;
 453     }
 454 
 455     public JCAssignOp Assignop(JCTree.Tag opcode, JCTree lhs, JCTree rhs) {
 456         JCAssignOp tree = new JCAssignOp(opcode, lhs, rhs, null);
 457         tree.pos = pos;
 458         return tree;
 459     }
 460 
 461     public JCUnary Unary(JCTree.Tag opcode, JCExpression arg) {
 462         JCUnary tree = new JCUnary(opcode, arg);
 463         tree.pos = pos;
 464         return tree;
 465     }
 466 
 467     public JCBinary Binary(JCTree.Tag opcode, JCExpression lhs, JCExpression rhs) {
 468         JCBinary tree = new JCBinary(opcode, lhs, rhs, null);
 469         tree.pos = pos;
 470         return tree;
 471     }
 472 
 473     public JCTypeCast TypeCast(JCTree clazz, JCExpression expr) {
 474         JCTypeCast tree = new JCTypeCast(clazz, expr);
 475         tree.pos = pos;
 476         return tree;
 477     }
 478 
 479     public JCInstanceOf TypeTest(JCExpression expr, JCTree clazz) {
 480         JCInstanceOf tree = new JCInstanceOf(expr, clazz);
 481         tree.pos = pos;
 482         return tree;
 483     }
 484 
 485     public JCBindingPattern BindingPattern(JCVariableDecl var) {
 486         JCBindingPattern tree = new JCBindingPattern(var);
 487         tree.pos = pos;
 488         return tree;
 489     }
 490 
 491     public JCDefaultCaseLabel DefaultCaseLabel() {
 492         JCDefaultCaseLabel tree = new JCDefaultCaseLabel();
 493         tree.pos = pos;
 494         return tree;
 495     }
 496 
 497     public JCParenthesizedPattern ParenthesizedPattern(JCPattern pattern) {
 498         JCParenthesizedPattern tree = new JCParenthesizedPattern(pattern);
 499         tree.pos = pos;
 500         return tree;
 501     }
 502 
 503     public JCGuardPattern GuardPattern(JCPattern guardedPattern, JCExpression expr) {
 504         JCGuardPattern tree = new JCGuardPattern(guardedPattern, expr);
 505         tree.pos = pos;
 506         return tree;
 507     }
 508 
 509     public JCArrayAccess Indexed(JCExpression indexed, JCExpression index) {
 510         JCArrayAccess tree = new JCArrayAccess(indexed, index);
 511         tree.pos = pos;
 512         return tree;
 513     }
 514 
 515     public JCFieldAccess Select(JCExpression selected, Name selector) {
 516         JCFieldAccess tree = new JCFieldAccess(selected, selector, null);
 517         tree.pos = pos;
 518         return tree;
 519     }
 520 
 521     public JCMemberReference Reference(JCMemberReference.ReferenceMode mode, Name name,
 522             JCExpression expr, List<JCExpression> typeargs) {
 523         JCMemberReference tree = new JCMemberReference(mode, name, expr, typeargs);
 524         tree.pos = pos;
 525         return tree;
 526     }
 527 
 528     public JCIdent Ident(Name name) {
 529         JCIdent tree = new JCIdent(name, null);
 530         tree.pos = pos;
 531         return tree;
 532     }
 533 
 534     public JCLiteral Literal(TypeTag tag, Object value) {
 535         JCLiteral tree = new JCLiteral(tag, value);
 536         tree.pos = pos;
 537         return tree;
 538     }
 539 
 540     public JCPrimitiveTypeTree TypeIdent(TypeTag typetag) {
 541         JCPrimitiveTypeTree tree = new JCPrimitiveTypeTree(typetag);
 542         tree.pos = pos;
 543         return tree;
 544     }
 545 
 546     public JCArrayTypeTree TypeArray(JCExpression elemtype) {
 547         JCArrayTypeTree tree = new JCArrayTypeTree(elemtype);
 548         tree.pos = pos;
 549         return tree;
 550     }
 551 
 552     public JCTypeApply TypeApply(JCExpression clazz, List<JCExpression> arguments) {
 553         JCTypeApply tree = new JCTypeApply(clazz, arguments);
 554         tree.pos = pos;
 555         return tree;
 556     }
 557 
 558     public JCTypeUnion TypeUnion(List<JCExpression> components) {
 559         JCTypeUnion tree = new JCTypeUnion(components);
 560         tree.pos = pos;
 561         return tree;
 562     }
 563 
 564     public JCTypeIntersection TypeIntersection(List<JCExpression> components) {
 565         JCTypeIntersection tree = new JCTypeIntersection(components);
 566         tree.pos = pos;
 567         return tree;
 568     }
 569 
 570     public JCTypeParameter TypeParameter(Name name, List<JCExpression> bounds) {
 571         return TypeParameter(name, bounds, List.nil());
 572     }
 573 
 574     public JCTypeParameter TypeParameter(Name name, List<JCExpression> bounds, List<JCAnnotation> annos) {
 575         JCTypeParameter tree = new JCTypeParameter(name, bounds, annos);
 576         tree.pos = pos;
 577         return tree;
 578     }
 579 
 580     public JCWildcard Wildcard(TypeBoundKind kind, JCTree type) {
 581         JCWildcard tree = new JCWildcard(kind, type);
 582         tree.pos = pos;
 583         return tree;
 584     }
 585 
 586     public TypeBoundKind TypeBoundKind(BoundKind kind) {
 587         TypeBoundKind tree = new TypeBoundKind(kind);
 588         tree.pos = pos;
 589         return tree;
 590     }
 591 
 592     public JCAnnotation Annotation(JCTree annotationType, List<JCExpression> args) {
 593         JCAnnotation tree = new JCAnnotation(Tag.ANNOTATION, annotationType, args);
 594         tree.pos = pos;
 595         return tree;
 596     }
 597 
 598     public JCAnnotation TypeAnnotation(JCTree annotationType, List<JCExpression> args) {
 599         JCAnnotation tree = new JCAnnotation(Tag.TYPE_ANNOTATION, annotationType, args);
 600         tree.pos = pos;
 601         return tree;
 602     }
 603 
 604     public JCModifiers Modifiers(long flags, List<JCAnnotation> annotations) {
 605         JCModifiers tree = new JCModifiers(flags, annotations);
 606         boolean noFlags = (flags & (Flags.ModifierFlags | Flags.ANNOTATION)) == 0;
 607         tree.pos = (noFlags && annotations.isEmpty()) ? Position.NOPOS : pos;
 608         return tree;
 609     }
 610 
 611     public JCModifiers Modifiers(long flags) {
 612         return Modifiers(flags, List.nil());
 613     }
 614 
 615     @Override
 616     public JCModuleDecl ModuleDef(JCModifiers mods, ModuleKind kind,
 617             JCExpression qualid, List<JCDirective> directives) {
 618         JCModuleDecl tree = new JCModuleDecl(mods, kind, qualid, directives);
 619         tree.pos = pos;
 620         return tree;
 621     }
 622 
 623     @Override
 624     public JCExports Exports(JCExpression qualId, List<JCExpression> moduleNames) {
 625         JCExports tree = new JCExports(qualId, moduleNames);
 626         tree.pos = pos;
 627         return tree;
 628     }
 629 
 630     @Override
 631     public JCOpens Opens(JCExpression qualId, List<JCExpression> moduleNames) {
 632         JCOpens tree = new JCOpens(qualId, moduleNames);
 633         tree.pos = pos;
 634         return tree;
 635     }
 636 
 637     @Override
 638     public JCProvides Provides(JCExpression serviceName, List<JCExpression> implNames) {
 639         JCProvides tree = new JCProvides(serviceName, implNames);
 640         tree.pos = pos;
 641         return tree;
 642     }
 643 
 644     @Override
 645     public JCRequires Requires(boolean isTransitive, boolean isStaticPhase, JCExpression qualId) {
 646         JCRequires tree = new JCRequires(isTransitive, isStaticPhase, qualId);
 647         tree.pos = pos;
 648         return tree;
 649     }
 650 
 651     @Override
 652     public JCUses Uses(JCExpression qualId) {
 653         JCUses tree = new JCUses(qualId);
 654         tree.pos = pos;
 655         return tree;
 656     }
 657 
 658     public JCAnnotatedType AnnotatedType(List<JCAnnotation> annotations, JCExpression underlyingType) {
 659         JCAnnotatedType tree = new JCAnnotatedType(annotations, underlyingType);
 660         tree.pos = pos;
 661         return tree;
 662     }
 663 
 664     public JCErroneous Erroneous() {
 665         return Erroneous(List.nil());
 666     }
 667 
 668     public JCErroneous Erroneous(List<? extends JCTree> errs) {
 669         JCErroneous tree = new JCErroneous(errs);
 670         tree.pos = pos;
 671         return tree;
 672     }
 673 
 674     public LetExpr LetExpr(List<JCStatement> defs, JCExpression expr) {
 675         LetExpr tree = new LetExpr(defs, expr);
 676         tree.pos = pos;
 677         return tree;
 678     }
 679 
 680 /* ***************************************************************************
 681  * Derived building blocks.
 682  ****************************************************************************/
 683 
 684     public JCClassDecl AnonymousClassDef(JCModifiers mods,
 685                                          List<JCTree> defs)
 686     {
 687         return ClassDef(mods,
 688                         names.empty,
 689                         List.nil(),
 690                         null,
 691                         List.nil(),
 692                         defs);
 693     }
 694 
 695     public LetExpr LetExpr(JCVariableDecl def, JCExpression expr) {
 696         LetExpr tree = new LetExpr(List.of(def), expr);
 697         tree.pos = pos;
 698         return tree;
 699     }
 700 
 701     /** Create an identifier from a symbol.
 702      */
 703     public JCIdent Ident(Symbol sym) {
 704         return (JCIdent)new JCIdent((sym.name != names.empty)
 705                                 ? sym.name
 706                                 : sym.flatName(), sym)
 707             .setPos(pos)
 708             .setType(sym.type);
 709     }
 710 
 711     /** Create a selection node from a qualifier tree and a symbol.
 712      *  @param base   The qualifier tree.
 713      */
 714     public JCExpression Select(JCExpression base, Symbol sym) {
 715         return new JCFieldAccess(base, sym.name, sym).setPos(pos).setType(sym.type);
 716     }
 717 
 718     /** Create a qualified identifier from a symbol, adding enough qualifications
 719      *  to make the reference unique.
 720      */
 721     public JCExpression QualIdent(Symbol sym) {
 722         return isUnqualifiable(sym)
 723             ? Ident(sym)
 724             : Select(QualIdent(sym.owner), sym);
 725     }
 726 
 727     /** Create an identifier that refers to the variable declared in given variable
 728      *  declaration.
 729      */
 730     public JCExpression Ident(JCVariableDecl param) {
 731         return Ident(param.sym);
 732     }
 733 
 734     /** Create a list of identifiers referring to the variables declared
 735      *  in given list of variable declarations.
 736      */
 737     public List<JCExpression> Idents(List<JCVariableDecl> params) {
 738         ListBuffer<JCExpression> ids = new ListBuffer<>();
 739         for (List<JCVariableDecl> l = params; l.nonEmpty(); l = l.tail)
 740             ids.append(Ident(l.head));
 741         return ids.toList();
 742     }
 743 
 744     /** Create a tree representing `this', given its type.
 745      */
 746     public JCExpression This(Type t) {
 747         return Ident(new VarSymbol(FINAL, names._this, t, t.tsym));
 748     }
 749 
 750     /** Create a tree representing qualified `this' given its type
 751      */
 752     public JCExpression QualThis(Type t) {
 753         return Select(Type(t), new VarSymbol(FINAL, names._this, t, t.tsym));
 754     }
 755 
 756     /** Create a tree representing a class literal.
 757      */
 758     public JCExpression ClassLiteral(ClassSymbol clazz) {
 759         return ClassLiteral(clazz.type);
 760     }
 761 
 762     /** Create a tree representing a class literal.
 763      */
 764     public JCExpression ClassLiteral(Type t) {
 765         VarSymbol lit = new VarSymbol(STATIC | PUBLIC | FINAL,
 766                                       names._class,
 767                                       t,
 768                                       t.tsym);
 769         return Select(Type(t), lit);
 770     }
 771 
 772     /** Create a tree representing `super', given its type and owner.
 773      */
 774     public JCIdent Super(Type t, TypeSymbol owner) {
 775         return Ident(new VarSymbol(FINAL, names._super, t, owner));
 776     }
 777 
 778     /**
 779      * Create a method invocation from a method tree and a list of
 780      * argument trees.
 781      */
 782     public JCMethodInvocation App(JCExpression meth, List<JCExpression> args) {
 783         return Apply(null, meth, args).setType(meth.type.getReturnType());
 784     }
 785 
 786     /**
 787      * Create a no-arg method invocation from a method tree
 788      */
 789     public JCMethodInvocation App(JCExpression meth) {
 790         return Apply(null, meth, List.nil()).setType(meth.type.getReturnType());
 791     }
 792 
 793     /** Create a method invocation from a method tree and a list of argument trees.
 794      */
 795     public JCExpression Create(Symbol ctor, List<JCExpression> args) {
 796         Type t = ctor.owner.erasure(types);
 797         JCNewClass newclass = NewClass(null, null, Type(t), args, null);
 798         newclass.constructor = ctor;
 799         newclass.setType(t);
 800         return newclass;
 801     }
 802 
 803     /** Create a tree representing given type.
 804      */
 805     public JCExpression Type(Type t) {
 806         if (t == null) return null;
 807         JCExpression tp;
 808         switch (t.getTag()) {
 809         case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
 810         case DOUBLE: case BOOLEAN: case VOID:
 811             tp = TypeIdent(t.getTag());
 812             break;
 813         case TYPEVAR:
 814             tp = Ident(t.tsym);
 815             break;
 816         case WILDCARD: {
 817             WildcardType a = ((WildcardType) t);
 818             tp = Wildcard(TypeBoundKind(a.kind), a.kind == BoundKind.UNBOUND ? null : Type(a.type));
 819             break;
 820         }
 821         case CLASS:
 822             switch (t.getKind()) {
 823             case UNION: {
 824                 UnionClassType tu = (UnionClassType)t;
 825                 ListBuffer<JCExpression> la = new ListBuffer<>();
 826                 for (Type ta : tu.getAlternativeTypes()) {
 827                     la.add(Type(ta));
 828                 }
 829                 tp = TypeUnion(la.toList());
 830                 break;
 831             }
 832             case INTERSECTION: {
 833                 IntersectionClassType it = (IntersectionClassType)t;
 834                 ListBuffer<JCExpression> la = new ListBuffer<>();
 835                 for (Type ta : it.getExplicitComponents()) {
 836                     la.add(Type(ta));
 837                 }
 838                 tp = TypeIntersection(la.toList());
 839                 break;
 840             }
 841             default: {
 842                 Type outer = t.getEnclosingType();
 843                 JCExpression clazz = outer.hasTag(CLASS) && t.tsym.owner.kind == TYP
 844                         ? Select(Type(outer), t.tsym)
 845                         : QualIdent(t.tsym);
 846                 tp = t.getTypeArguments().isEmpty()
 847                         ? clazz
 848                         : TypeApply(clazz, Types(t.getTypeArguments()));
 849                 break;
 850             }
 851             }
 852             break;
 853         case ARRAY:
 854             tp = TypeArray(Type(types.elemtype(t)));
 855             break;
 856         case ERROR:
 857             tp = TypeIdent(ERROR);
 858             break;
 859         default:
 860             throw new AssertionError("unexpected type: " + t);
 861         }
 862         return tp.setType(t);
 863     }
 864 
 865     /** Create a list of trees representing given list of types.
 866      */
 867     public List<JCExpression> Types(List<Type> ts) {
 868         ListBuffer<JCExpression> lb = new ListBuffer<>();
 869         for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
 870             lb.append(Type(l.head));
 871         return lb.toList();
 872     }
 873 
 874     /** Create a variable definition from a variable symbol and an initializer
 875      *  expression.
 876      */
 877     public JCVariableDecl VarDef(VarSymbol v, JCExpression init) {
 878         return (JCVariableDecl)
 879             new JCVariableDecl(
 880                 Modifiers(v.flags(), Annotations(v.getRawAttributes())),
 881                 v.name,
 882                 Type(v.type),
 883                 init,
 884                 v).setPos(pos).setType(v.type);
 885     }
 886 
 887     /** Create annotation trees from annotations.
 888      */
 889     public List<JCAnnotation> Annotations(List<Attribute.Compound> attributes) {
 890         if (attributes == null) return List.nil();
 891         ListBuffer<JCAnnotation> result = new ListBuffer<>();
 892         for (List<Attribute.Compound> i = attributes; i.nonEmpty(); i=i.tail) {
 893             Attribute a = i.head;
 894             result.append(Annotation(a));
 895         }
 896         return result.toList();
 897     }
 898 
 899     public JCLiteral Literal(Object value) {
 900         JCLiteral result = null;
 901         if (value instanceof String) {
 902             result = Literal(CLASS, value).
 903                 setType(syms.stringType.constType(value));
 904         } else if (value instanceof Integer) {
 905             result = Literal(INT, value).
 906                 setType(syms.intType.constType(value));
 907         } else if (value instanceof Long) {
 908             result = Literal(LONG, value).
 909                 setType(syms.longType.constType(value));
 910         } else if (value instanceof Byte) {
 911             result = Literal(BYTE, value).
 912                 setType(syms.byteType.constType(value));
 913         } else if (value instanceof Character charVal) {
 914             int v = charVal.toString().charAt(0);
 915             result = Literal(CHAR, v).
 916                 setType(syms.charType.constType(v));
 917         } else if (value instanceof Double) {
 918             result = Literal(DOUBLE, value).
 919                 setType(syms.doubleType.constType(value));
 920         } else if (value instanceof Float) {
 921             result = Literal(FLOAT, value).
 922                 setType(syms.floatType.constType(value));
 923         } else if (value instanceof Short) {
 924             result = Literal(SHORT, value).
 925                 setType(syms.shortType.constType(value));
 926         } else if (value instanceof Boolean boolVal) {
 927             int v = boolVal ? 1 : 0;
 928             result = Literal(BOOLEAN, v).
 929                 setType(syms.booleanType.constType(v));
 930         } else {
 931             throw new AssertionError(value);
 932         }
 933         return result;
 934     }
 935 
 936     class AnnotationBuilder implements Attribute.Visitor {
 937         JCExpression result = null;
 938         public void visitConstant(Attribute.Constant v) {
 939             result = Literal(v.type.getTag(), v.value);
 940         }
 941         public void visitClass(Attribute.Class clazz) {
 942             result = ClassLiteral(clazz.classType).setType(syms.classType);
 943         }
 944         public void visitEnum(Attribute.Enum e) {
 945             result = QualIdent(e.value);
 946         }
 947         public void visitError(Attribute.Error e) {
 948             if (e instanceof UnresolvedClass unresolvedClass) {
 949                 result = ClassLiteral(unresolvedClass.classType).setType(syms.classType);
 950             } else {
 951                 result = Erroneous();
 952             }
 953         }
 954         public void visitCompound(Attribute.Compound compound) {
 955             if (compound instanceof Attribute.TypeCompound typeCompound) {
 956                 result = visitTypeCompoundInternal(typeCompound);
 957             } else {
 958                 result = visitCompoundInternal(compound);
 959             }
 960         }
 961         public JCAnnotation visitCompoundInternal(Attribute.Compound compound) {
 962             ListBuffer<JCExpression> args = new ListBuffer<>();
 963             for (List<Pair<Symbol.MethodSymbol,Attribute>> values = compound.values; values.nonEmpty(); values=values.tail) {
 964                 Pair<MethodSymbol,Attribute> pair = values.head;
 965                 JCExpression valueTree = translate(pair.snd);
 966                 args.append(Assign(Ident(pair.fst), valueTree).setType(valueTree.type));
 967             }
 968             return Annotation(Type(compound.type), args.toList());
 969         }
 970         public JCAnnotation visitTypeCompoundInternal(Attribute.TypeCompound compound) {
 971             ListBuffer<JCExpression> args = new ListBuffer<>();
 972             for (List<Pair<Symbol.MethodSymbol,Attribute>> values = compound.values; values.nonEmpty(); values=values.tail) {
 973                 Pair<MethodSymbol,Attribute> pair = values.head;
 974                 JCExpression valueTree = translate(pair.snd);
 975                 args.append(Assign(Ident(pair.fst), valueTree).setType(valueTree.type));
 976             }
 977             return TypeAnnotation(Type(compound.type), args.toList());
 978         }
 979         public void visitArray(Attribute.Array array) {
 980             ListBuffer<JCExpression> elems = new ListBuffer<>();
 981             for (int i = 0; i < array.values.length; i++)
 982                 elems.append(translate(array.values[i]));
 983             result = NewArray(null, List.nil(), elems.toList()).setType(array.type);
 984         }
 985         JCExpression translate(Attribute a) {
 986             a.accept(this);
 987             return result;
 988         }
 989         JCAnnotation translate(Attribute.Compound a) {
 990             return visitCompoundInternal(a);
 991         }
 992         JCAnnotation translate(Attribute.TypeCompound a) {
 993             return visitTypeCompoundInternal(a);
 994         }
 995     }
 996 
 997     AnnotationBuilder annotationBuilder = new AnnotationBuilder();
 998 
 999     /** Create an annotation tree from an attribute.
1000      */
1001     public JCAnnotation Annotation(Attribute a) {
1002         return annotationBuilder.translate((Attribute.Compound)a);
1003     }
1004 
1005     public JCAnnotation TypeAnnotation(Attribute a) {
1006         return annotationBuilder.translate((Attribute.TypeCompound) a);
1007     }
1008 
1009     /** Create a method definition from a method symbol and a method body.
1010      */
1011     public JCMethodDecl MethodDef(MethodSymbol m, JCBlock body) {
1012         return MethodDef(m, m.type, body);
1013     }
1014 
1015     /** Create a method definition from a method symbol, method type
1016      *  and a method body.
1017      */
1018     public JCMethodDecl MethodDef(MethodSymbol m, Type mtype, JCBlock body) {
1019         return (JCMethodDecl)
1020             new JCMethodDecl(
1021                 Modifiers(m.flags(), Annotations(m.getRawAttributes())),
1022                 m.name,
1023                 m.name != names.init ? Type(mtype.getReturnType()) : null,
1024                 TypeParams(mtype.getTypeArguments()),
1025                 null, // receiver type
1026                 Params(mtype.getParameterTypes(), m),
1027                 Types(mtype.getThrownTypes()),
1028                 body,
1029                 null,
1030                 m).setPos(pos).setType(mtype);
1031     }
1032 
1033     /** Create a type parameter tree from its name and type.
1034      */
1035     public JCTypeParameter TypeParam(Name name, TypeVar tvar) {
1036         return (JCTypeParameter)
1037             TypeParameter(name, Types(types.getBounds(tvar))).setPos(pos).setType(tvar);
1038     }
1039 
1040     /** Create a list of type parameter trees from a list of type variables.
1041      */
1042     public List<JCTypeParameter> TypeParams(List<Type> typarams) {
1043         ListBuffer<JCTypeParameter> tparams = new ListBuffer<>();
1044         for (List<Type> l = typarams; l.nonEmpty(); l = l.tail)
1045             tparams.append(TypeParam(l.head.tsym.name, (TypeVar)l.head));
1046         return tparams.toList();
1047     }
1048 
1049     /** Create a value parameter tree from its name, type, and owner.
1050      */
1051     public JCVariableDecl Param(Name name, Type argtype, Symbol owner) {
1052         return VarDef(new VarSymbol(PARAMETER, name, argtype, owner), null);
1053     }
1054 
1055     /** Create a a list of value parameter trees x0, ..., xn from a list of
1056      *  their types and an their owner.
1057      */
1058     public List<JCVariableDecl> Params(List<Type> argtypes, Symbol owner) {
1059         ListBuffer<JCVariableDecl> params = new ListBuffer<>();
1060         MethodSymbol mth = (owner.kind == MTH) ? ((MethodSymbol)owner) : null;
1061         if (mth != null && mth.params != null && argtypes.length() == mth.params.length()) {
1062             for (VarSymbol param : ((MethodSymbol)owner).params)
1063                 params.append(VarDef(param, null));
1064         } else {
1065             int i = 0;
1066             for (List<Type> l = argtypes; l.nonEmpty(); l = l.tail)
1067                 params.append(Param(paramName(i++), l.head, owner));
1068         }
1069         return params.toList();
1070     }
1071 
1072     /** Wrap a method invocation in an expression statement or return statement,
1073      *  depending on whether the method invocation expression's type is void.
1074      */
1075     public JCStatement Call(JCExpression apply) {
1076         return apply.type.hasTag(VOID) ? Exec(apply) : Return(apply);
1077     }
1078 
1079     /** Construct an assignment from a variable symbol and a right hand side.
1080      */
1081     public JCStatement Assignment(Symbol v, JCExpression rhs) {
1082         return Exec(Assign(Ident(v), rhs).setType(v.type));
1083     }
1084 
1085     /** Construct an index expression from a variable and an expression.
1086      */
1087     public JCArrayAccess Indexed(Symbol v, JCExpression index) {
1088         JCArrayAccess tree = new JCArrayAccess(QualIdent(v), index);
1089         tree.type = ((ArrayType)v.type).elemtype;
1090         return tree;
1091     }
1092 
1093     /** Make an attributed type cast expression.
1094      */
1095     public JCTypeCast TypeCast(Type type, JCExpression expr) {
1096         return (JCTypeCast)TypeCast(Type(type), expr).setType(type);
1097     }
1098 
1099 /* ***************************************************************************
1100  * Helper methods.
1101  ****************************************************************************/
1102 
1103     /** Can given symbol be referred to in unqualified form?
1104      */
1105     boolean isUnqualifiable(Symbol sym) {
1106         if (sym.name == names.empty ||
1107             sym.owner == null ||
1108             sym.owner == syms.rootPackage ||
1109             sym.owner.kind == MTH || sym.owner.kind == VAR) {
1110             return true;
1111         } else if (sym.kind == TYP && toplevel != null) {
1112             Iterator<Symbol> it = toplevel.namedImportScope.getSymbolsByName(sym.name).iterator();
1113             if (it.hasNext()) {
1114                 Symbol s = it.next();
1115                 return
1116                   s == sym &&
1117                   !it.hasNext();
1118             }
1119             it = toplevel.packge.members().getSymbolsByName(sym.name).iterator();
1120             if (it.hasNext()) {
1121                 Symbol s = it.next();
1122                 return
1123                   s == sym &&
1124                   !it.hasNext();
1125             }
1126             it = toplevel.starImportScope.getSymbolsByName(sym.name).iterator();
1127             if (it.hasNext()) {
1128                 Symbol s = it.next();
1129                 return
1130                   s == sym &&
1131                   !it.hasNext();
1132             }
1133         }
1134         return false;
1135     }
1136 
1137     /** The name of synthetic parameter number `i'.
1138      */
1139     public Name paramName(int i)   { return names.fromString("x" + i); }
1140 
1141     /** The name of synthetic type parameter number `i'.
1142      */
1143     public Name typaramName(int i) { return names.fromString("A" + i); }
1144 }