src/share/classes/com/sun/tools/javac/comp/Lower.java

Mon, 16 Oct 2017 16:07:48 +0800

author
aoqi
date
Mon, 16 Oct 2017 16:07:48 +0800
changeset 2893
ca5783d9a597
parent 2789
36ed04994588
parent 2702
9ca8d8713094
permissions
-rw-r--r--

merge

     1 /*
     2  * Copyright (c) 1999, 2014, 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  */
    26 package com.sun.tools.javac.comp;
    28 import java.util.*;
    30 import com.sun.tools.javac.code.*;
    31 import com.sun.tools.javac.code.Type.AnnotatedType;
    32 import com.sun.tools.javac.jvm.*;
    33 import com.sun.tools.javac.main.Option.PkgInfo;
    34 import com.sun.tools.javac.tree.*;
    35 import com.sun.tools.javac.util.*;
    36 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
    37 import com.sun.tools.javac.util.List;
    39 import com.sun.tools.javac.code.Symbol.*;
    40 import com.sun.tools.javac.tree.JCTree.*;
    41 import com.sun.tools.javac.code.Type.*;
    43 import com.sun.tools.javac.jvm.Target;
    44 import com.sun.tools.javac.tree.EndPosTable;
    46 import static com.sun.tools.javac.code.Flags.*;
    47 import static com.sun.tools.javac.code.Flags.BLOCK;
    48 import static com.sun.tools.javac.code.Kinds.*;
    49 import static com.sun.tools.javac.code.TypeTag.*;
    50 import static com.sun.tools.javac.jvm.ByteCodes.*;
    51 import static com.sun.tools.javac.tree.JCTree.Tag.*;
    53 /** This pass translates away some syntactic sugar: inner classes,
    54  *  class literals, assertions, foreach loops, etc.
    55  *
    56  *  <p><b>This is NOT part of any supported API.
    57  *  If you write code that depends on this, you do so at your own risk.
    58  *  This code and its internal interfaces are subject to change or
    59  *  deletion without notice.</b>
    60  */
    61 public class Lower extends TreeTranslator {
    62     protected static final Context.Key<Lower> lowerKey =
    63         new Context.Key<Lower>();
    65     public static Lower instance(Context context) {
    66         Lower instance = context.get(lowerKey);
    67         if (instance == null)
    68             instance = new Lower(context);
    69         return instance;
    70     }
    72     private Names names;
    73     private Log log;
    74     private Symtab syms;
    75     private Resolve rs;
    76     private Check chk;
    77     private Attr attr;
    78     private TreeMaker make;
    79     private DiagnosticPosition make_pos;
    80     private ClassWriter writer;
    81     private ClassReader reader;
    82     private ConstFold cfolder;
    83     private Target target;
    84     private Source source;
    85     private final TypeEnvs typeEnvs;
    86     private boolean allowEnums;
    87     private final Name dollarAssertionsDisabled;
    88     private final Name classDollar;
    89     private Types types;
    90     private boolean debugLower;
    91     private PkgInfo pkginfoOpt;
    93     protected Lower(Context context) {
    94         context.put(lowerKey, this);
    95         names = Names.instance(context);
    96         log = Log.instance(context);
    97         syms = Symtab.instance(context);
    98         rs = Resolve.instance(context);
    99         chk = Check.instance(context);
   100         attr = Attr.instance(context);
   101         make = TreeMaker.instance(context);
   102         writer = ClassWriter.instance(context);
   103         reader = ClassReader.instance(context);
   104         cfolder = ConstFold.instance(context);
   105         target = Target.instance(context);
   106         source = Source.instance(context);
   107         typeEnvs = TypeEnvs.instance(context);
   108         allowEnums = source.allowEnums();
   109         dollarAssertionsDisabled = names.
   110             fromString(target.syntheticNameChar() + "assertionsDisabled");
   111         classDollar = names.
   112             fromString("class" + target.syntheticNameChar());
   114         types = Types.instance(context);
   115         Options options = Options.instance(context);
   116         debugLower = options.isSet("debuglower");
   117         pkginfoOpt = PkgInfo.get(options);
   118     }
   120     /** The currently enclosing class.
   121      */
   122     ClassSymbol currentClass;
   124     /** A queue of all translated classes.
   125      */
   126     ListBuffer<JCTree> translated;
   128     /** Environment for symbol lookup, set by translateTopLevelClass.
   129      */
   130     Env<AttrContext> attrEnv;
   132     /** A hash table mapping syntax trees to their ending source positions.
   133      */
   134     EndPosTable endPosTable;
   136 /**************************************************************************
   137  * Global mappings
   138  *************************************************************************/
   140     /** A hash table mapping local classes to their definitions.
   141      */
   142     Map<ClassSymbol, JCClassDecl> classdefs;
   144     /** A hash table mapping local classes to a list of pruned trees.
   145      */
   146     public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<ClassSymbol, List<JCTree>>();
   148     /** A hash table mapping virtual accessed symbols in outer subclasses
   149      *  to the actually referred symbol in superclasses.
   150      */
   151     Map<Symbol,Symbol> actualSymbols;
   153     /** The current method definition.
   154      */
   155     JCMethodDecl currentMethodDef;
   157     /** The current method symbol.
   158      */
   159     MethodSymbol currentMethodSym;
   161     /** The currently enclosing outermost class definition.
   162      */
   163     JCClassDecl outermostClassDef;
   165     /** The currently enclosing outermost member definition.
   166      */
   167     JCTree outermostMemberDef;
   169     /** A map from local variable symbols to their translation (as per LambdaToMethod).
   170      * This is required when a capturing local class is created from a lambda (in which
   171      * case the captured symbols should be replaced with the translated lambda symbols).
   172      */
   173     Map<Symbol, Symbol> lambdaTranslationMap = null;
   175     /** A navigator class for assembling a mapping from local class symbols
   176      *  to class definition trees.
   177      *  There is only one case; all other cases simply traverse down the tree.
   178      */
   179     class ClassMap extends TreeScanner {
   181         /** All encountered class defs are entered into classdefs table.
   182          */
   183         public void visitClassDef(JCClassDecl tree) {
   184             classdefs.put(tree.sym, tree);
   185             super.visitClassDef(tree);
   186         }
   187     }
   188     ClassMap classMap = new ClassMap();
   190     /** Map a class symbol to its definition.
   191      *  @param c    The class symbol of which we want to determine the definition.
   192      */
   193     JCClassDecl classDef(ClassSymbol c) {
   194         // First lookup the class in the classdefs table.
   195         JCClassDecl def = classdefs.get(c);
   196         if (def == null && outermostMemberDef != null) {
   197             // If this fails, traverse outermost member definition, entering all
   198             // local classes into classdefs, and try again.
   199             classMap.scan(outermostMemberDef);
   200             def = classdefs.get(c);
   201         }
   202         if (def == null) {
   203             // If this fails, traverse outermost class definition, entering all
   204             // local classes into classdefs, and try again.
   205             classMap.scan(outermostClassDef);
   206             def = classdefs.get(c);
   207         }
   208         return def;
   209     }
   211     /** A hash table mapping class symbols to lists of free variables.
   212      *  accessed by them. Only free variables of the method immediately containing
   213      *  a class are associated with that class.
   214      */
   215     Map<ClassSymbol,List<VarSymbol>> freevarCache;
   217     /** A navigator class for collecting the free variables accessed
   218      *  from a local class. There is only one case; all other cases simply
   219      *  traverse down the tree. This class doesn't deal with the specific
   220      *  of Lower - it's an abstract visitor that is meant to be reused in
   221      *  order to share the local variable capture logic.
   222      */
   223     abstract class BasicFreeVarCollector extends TreeScanner {
   225         /** Add all free variables of class c to fvs list
   226          *  unless they are already there.
   227          */
   228         abstract void addFreeVars(ClassSymbol c);
   230         /** If tree refers to a variable in owner of local class, add it to
   231          *  free variables list.
   232          */
   233         public void visitIdent(JCIdent tree) {
   234             visitSymbol(tree.sym);
   235         }
   236         // where
   237         abstract void visitSymbol(Symbol _sym);
   239         /** If tree refers to a class instance creation expression
   240          *  add all free variables of the freshly created class.
   241          */
   242         public void visitNewClass(JCNewClass tree) {
   243             ClassSymbol c = (ClassSymbol)tree.constructor.owner;
   244             addFreeVars(c);
   245             super.visitNewClass(tree);
   246         }
   248         /** If tree refers to a superclass constructor call,
   249          *  add all free variables of the superclass.
   250          */
   251         public void visitApply(JCMethodInvocation tree) {
   252             if (TreeInfo.name(tree.meth) == names._super) {
   253                 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner);
   254             }
   255             super.visitApply(tree);
   256         }
   257     }
   259     /**
   260      * Lower-specific subclass of {@code BasicFreeVarCollector}.
   261      */
   262     class FreeVarCollector extends BasicFreeVarCollector {
   264         /** The owner of the local class.
   265          */
   266         Symbol owner;
   268         /** The local class.
   269          */
   270         ClassSymbol clazz;
   272         /** The list of owner's variables accessed from within the local class,
   273          *  without any duplicates.
   274          */
   275         List<VarSymbol> fvs;
   277         FreeVarCollector(ClassSymbol clazz) {
   278             this.clazz = clazz;
   279             this.owner = clazz.owner;
   280             this.fvs = List.nil();
   281         }
   283         /** Add free variable to fvs list unless it is already there.
   284          */
   285         private void addFreeVar(VarSymbol v) {
   286             for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail)
   287                 if (l.head == v) return;
   288             fvs = fvs.prepend(v);
   289         }
   291         @Override
   292         void addFreeVars(ClassSymbol c) {
   293             List<VarSymbol> fvs = freevarCache.get(c);
   294             if (fvs != null) {
   295                 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
   296                     addFreeVar(l.head);
   297                 }
   298             }
   299         }
   301         @Override
   302         void visitSymbol(Symbol _sym) {
   303             Symbol sym = _sym;
   304             if (sym.kind == VAR || sym.kind == MTH) {
   305                 while (sym != null && sym.owner != owner)
   306                     sym = proxies.lookup(proxyName(sym.name)).sym;
   307                 if (sym != null && sym.owner == owner) {
   308                     VarSymbol v = (VarSymbol)sym;
   309                     if (v.getConstValue() == null) {
   310                         addFreeVar(v);
   311                     }
   312                 } else {
   313                     if (outerThisStack.head != null &&
   314                         outerThisStack.head != _sym)
   315                         visitSymbol(outerThisStack.head);
   316                 }
   317             }
   318         }
   320         /** If tree refers to a class instance creation expression
   321          *  add all free variables of the freshly created class.
   322          */
   323         public void visitNewClass(JCNewClass tree) {
   324             ClassSymbol c = (ClassSymbol)tree.constructor.owner;
   325             if (tree.encl == null &&
   326                 c.hasOuterInstance() &&
   327                 outerThisStack.head != null)
   328                 visitSymbol(outerThisStack.head);
   329             super.visitNewClass(tree);
   330         }
   332         /** If tree refers to a qualified this or super expression
   333          *  for anything but the current class, add the outer this
   334          *  stack as a free variable.
   335          */
   336         public void visitSelect(JCFieldAccess tree) {
   337             if ((tree.name == names._this || tree.name == names._super) &&
   338                 tree.selected.type.tsym != clazz &&
   339                 outerThisStack.head != null)
   340                 visitSymbol(outerThisStack.head);
   341             super.visitSelect(tree);
   342         }
   344         /** If tree refers to a superclass constructor call,
   345          *  add all free variables of the superclass.
   346          */
   347         public void visitApply(JCMethodInvocation tree) {
   348             if (TreeInfo.name(tree.meth) == names._super) {
   349                 Symbol constructor = TreeInfo.symbol(tree.meth);
   350                 ClassSymbol c = (ClassSymbol)constructor.owner;
   351                 if (c.hasOuterInstance() &&
   352                     !tree.meth.hasTag(SELECT) &&
   353                     outerThisStack.head != null)
   354                     visitSymbol(outerThisStack.head);
   355             }
   356             super.visitApply(tree);
   357         }
   358     }
   360     ClassSymbol ownerToCopyFreeVarsFrom(ClassSymbol c) {
   361         if (!c.isLocal()) {
   362             return null;
   363         }
   364         Symbol currentOwner = c.owner;
   365         while ((currentOwner.owner.kind & TYP) != 0 && currentOwner.isLocal()) {
   366             currentOwner = currentOwner.owner;
   367         }
   368         if ((currentOwner.owner.kind & (VAR | MTH)) != 0 && c.isSubClass(currentOwner, types)) {
   369             return (ClassSymbol)currentOwner;
   370         }
   371         return null;
   372     }
   374     /** Return the variables accessed from within a local class, which
   375      *  are declared in the local class' owner.
   376      *  (in reverse order of first access).
   377      */
   378     List<VarSymbol> freevars(ClassSymbol c)  {
   379         List<VarSymbol> fvs = freevarCache.get(c);
   380         if (fvs != null) {
   381             return fvs;
   382         }
   383         if ((c.owner.kind & (VAR | MTH)) != 0) {
   384             FreeVarCollector collector = new FreeVarCollector(c);
   385             collector.scan(classDef(c));
   386             fvs = collector.fvs;
   387             freevarCache.put(c, fvs);
   388             return fvs;
   389         } else {
   390             ClassSymbol owner = ownerToCopyFreeVarsFrom(c);
   391             if (owner != null) {
   392                 fvs = freevarCache.get(owner);
   393                 freevarCache.put(c, fvs);
   394                 return fvs;
   395             } else {
   396                 return List.nil();
   397             }
   398         }
   399     }
   401     Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<TypeSymbol,EnumMapping>();
   403     EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) {
   404         EnumMapping map = enumSwitchMap.get(enumClass);
   405         if (map == null)
   406             enumSwitchMap.put(enumClass, map = new EnumMapping(pos, enumClass));
   407         return map;
   408     }
   410     /** This map gives a translation table to be used for enum
   411      *  switches.
   412      *
   413      *  <p>For each enum that appears as the type of a switch
   414      *  expression, we maintain an EnumMapping to assist in the
   415      *  translation, as exemplified by the following example:
   416      *
   417      *  <p>we translate
   418      *  <pre>
   419      *          switch(colorExpression) {
   420      *          case red: stmt1;
   421      *          case green: stmt2;
   422      *          }
   423      *  </pre>
   424      *  into
   425      *  <pre>
   426      *          switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) {
   427      *          case 1: stmt1;
   428      *          case 2: stmt2
   429      *          }
   430      *  </pre>
   431      *  with the auxiliary table initialized as follows:
   432      *  <pre>
   433      *          class Outer$0 {
   434      *              synthetic final int[] $EnumMap$Color = new int[Color.values().length];
   435      *              static {
   436      *                  try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {}
   437      *                  try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {}
   438      *              }
   439      *          }
   440      *  </pre>
   441      *  class EnumMapping provides mapping data and support methods for this translation.
   442      */
   443     class EnumMapping {
   444         EnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) {
   445             this.forEnum = forEnum;
   446             this.values = new LinkedHashMap<VarSymbol,Integer>();
   447             this.pos = pos;
   448             Name varName = names
   449                 .fromString(target.syntheticNameChar() +
   450                             "SwitchMap" +
   451                             target.syntheticNameChar() +
   452                             writer.xClassName(forEnum.type).toString()
   453                             .replace('/', '.')
   454                             .replace('.', target.syntheticNameChar()));
   455             ClassSymbol outerCacheClass = outerCacheClass();
   456             this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL,
   457                                         varName,
   458                                         new ArrayType(syms.intType, syms.arrayClass),
   459                                         outerCacheClass);
   460             enterSynthetic(pos, mapVar, outerCacheClass.members());
   461         }
   463         DiagnosticPosition pos = null;
   465         // the next value to use
   466         int next = 1; // 0 (unused map elements) go to the default label
   468         // the enum for which this is a map
   469         final TypeSymbol forEnum;
   471         // the field containing the map
   472         final VarSymbol mapVar;
   474         // the mapped values
   475         final Map<VarSymbol,Integer> values;
   477         JCLiteral forConstant(VarSymbol v) {
   478             Integer result = values.get(v);
   479             if (result == null)
   480                 values.put(v, result = next++);
   481             return make.Literal(result);
   482         }
   484         // generate the field initializer for the map
   485         void translate() {
   486             make.at(pos.getStartPosition());
   487             JCClassDecl owner = classDef((ClassSymbol)mapVar.owner);
   489             // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length];
   490             MethodSymbol valuesMethod = lookupMethod(pos,
   491                                                      names.values,
   492                                                      forEnum.type,
   493                                                      List.<Type>nil());
   494             JCExpression size = make // Color.values().length
   495                 .Select(make.App(make.QualIdent(valuesMethod)),
   496                         syms.lengthVar);
   497             JCExpression mapVarInit = make
   498                 .NewArray(make.Type(syms.intType), List.of(size), null)
   499                 .setType(new ArrayType(syms.intType, syms.arrayClass));
   501             // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {}
   502             ListBuffer<JCStatement> stmts = new ListBuffer<JCStatement>();
   503             Symbol ordinalMethod = lookupMethod(pos,
   504                                                 names.ordinal,
   505                                                 forEnum.type,
   506                                                 List.<Type>nil());
   507             List<JCCatch> catcher = List.<JCCatch>nil()
   508                 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex,
   509                                                               syms.noSuchFieldErrorType,
   510                                                               syms.noSymbol),
   511                                                 null),
   512                                     make.Block(0, List.<JCStatement>nil())));
   513             for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) {
   514                 VarSymbol enumerator = e.getKey();
   515                 Integer mappedValue = e.getValue();
   516                 JCExpression assign = make
   517                     .Assign(make.Indexed(mapVar,
   518                                          make.App(make.Select(make.QualIdent(enumerator),
   519                                                               ordinalMethod))),
   520                             make.Literal(mappedValue))
   521                     .setType(syms.intType);
   522                 JCStatement exec = make.Exec(assign);
   523                 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null);
   524                 stmts.append(_try);
   525             }
   527             owner.defs = owner.defs
   528                 .prepend(make.Block(STATIC, stmts.toList()))
   529                 .prepend(make.VarDef(mapVar, mapVarInit));
   530         }
   531     }
   534 /**************************************************************************
   535  * Tree building blocks
   536  *************************************************************************/
   538     /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching
   539      *  pos as make_pos, for use in diagnostics.
   540      **/
   541     TreeMaker make_at(DiagnosticPosition pos) {
   542         make_pos = pos;
   543         return make.at(pos);
   544     }
   546     /** Make an attributed tree representing a literal. This will be an
   547      *  Ident node in the case of boolean literals, a Literal node in all
   548      *  other cases.
   549      *  @param type       The literal's type.
   550      *  @param value      The literal's value.
   551      */
   552     JCExpression makeLit(Type type, Object value) {
   553         return make.Literal(type.getTag(), value).setType(type.constType(value));
   554     }
   556     /** Make an attributed tree representing null.
   557      */
   558     JCExpression makeNull() {
   559         return makeLit(syms.botType, null);
   560     }
   562     /** Make an attributed class instance creation expression.
   563      *  @param ctype    The class type.
   564      *  @param args     The constructor arguments.
   565      */
   566     JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
   567         JCNewClass tree = make.NewClass(null,
   568             null, make.QualIdent(ctype.tsym), args, null);
   569         tree.constructor = rs.resolveConstructor(
   570             make_pos, attrEnv, ctype, TreeInfo.types(args), List.<Type>nil());
   571         tree.type = ctype;
   572         return tree;
   573     }
   575     /** Make an attributed unary expression.
   576      *  @param optag    The operators tree tag.
   577      *  @param arg      The operator's argument.
   578      */
   579     JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) {
   580         JCUnary tree = make.Unary(optag, arg);
   581         tree.operator = rs.resolveUnaryOperator(
   582             make_pos, optag, attrEnv, arg.type);
   583         tree.type = tree.operator.type.getReturnType();
   584         return tree;
   585     }
   587     /** Make an attributed binary expression.
   588      *  @param optag    The operators tree tag.
   589      *  @param lhs      The operator's left argument.
   590      *  @param rhs      The operator's right argument.
   591      */
   592     JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) {
   593         JCBinary tree = make.Binary(optag, lhs, rhs);
   594         tree.operator = rs.resolveBinaryOperator(
   595             make_pos, optag, attrEnv, lhs.type, rhs.type);
   596         tree.type = tree.operator.type.getReturnType();
   597         return tree;
   598     }
   600     /** Make an attributed assignop expression.
   601      *  @param optag    The operators tree tag.
   602      *  @param lhs      The operator's left argument.
   603      *  @param rhs      The operator's right argument.
   604      */
   605     JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) {
   606         JCAssignOp tree = make.Assignop(optag, lhs, rhs);
   607         tree.operator = rs.resolveBinaryOperator(
   608             make_pos, tree.getTag().noAssignOp(), attrEnv, lhs.type, rhs.type);
   609         tree.type = lhs.type;
   610         return tree;
   611     }
   613     /** Convert tree into string object, unless it has already a
   614      *  reference type..
   615      */
   616     JCExpression makeString(JCExpression tree) {
   617         if (!tree.type.isPrimitiveOrVoid()) {
   618             return tree;
   619         } else {
   620             Symbol valueOfSym = lookupMethod(tree.pos(),
   621                                              names.valueOf,
   622                                              syms.stringType,
   623                                              List.of(tree.type));
   624             return make.App(make.QualIdent(valueOfSym), List.of(tree));
   625         }
   626     }
   628     /** Create an empty anonymous class definition and enter and complete
   629      *  its symbol. Return the class definition's symbol.
   630      *  and create
   631      *  @param flags    The class symbol's flags
   632      *  @param owner    The class symbol's owner
   633      */
   634     JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) {
   635         return makeEmptyClass(flags, owner, null, true);
   636     }
   638     JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname,
   639             boolean addToDefs) {
   640         // Create class symbol.
   641         ClassSymbol c = reader.defineClass(names.empty, owner);
   642         if (flatname != null) {
   643             c.flatname = flatname;
   644         } else {
   645             c.flatname = chk.localClassName(c);
   646         }
   647         c.sourcefile = owner.sourcefile;
   648         c.completer = null;
   649         c.members_field = new Scope(c);
   650         c.flags_field = flags;
   651         ClassType ctype = (ClassType) c.type;
   652         ctype.supertype_field = syms.objectType;
   653         ctype.interfaces_field = List.nil();
   655         JCClassDecl odef = classDef(owner);
   657         // Enter class symbol in owner scope and compiled table.
   658         enterSynthetic(odef.pos(), c, owner.members());
   659         chk.compiled.put(c.flatname, c);
   661         // Create class definition tree.
   662         JCClassDecl cdef = make.ClassDef(
   663             make.Modifiers(flags), names.empty,
   664             List.<JCTypeParameter>nil(),
   665             null, List.<JCExpression>nil(), List.<JCTree>nil());
   666         cdef.sym = c;
   667         cdef.type = c.type;
   669         // Append class definition tree to owner's definitions.
   670         if (addToDefs) odef.defs = odef.defs.prepend(cdef);
   671         return cdef;
   672     }
   674 /**************************************************************************
   675  * Symbol manipulation utilities
   676  *************************************************************************/
   678     /** Enter a synthetic symbol in a given scope, but complain if there was already one there.
   679      *  @param pos           Position for error reporting.
   680      *  @param sym           The symbol.
   681      *  @param s             The scope.
   682      */
   683     private void enterSynthetic(DiagnosticPosition pos, Symbol sym, Scope s) {
   684         s.enter(sym);
   685     }
   687     /** Create a fresh synthetic name within a given scope - the unique name is
   688      *  obtained by appending '$' chars at the end of the name until no match
   689      *  is found.
   690      *
   691      * @param name base name
   692      * @param s scope in which the name has to be unique
   693      * @return fresh synthetic name
   694      */
   695     private Name makeSyntheticName(Name name, Scope s) {
   696         do {
   697             name = name.append(
   698                     target.syntheticNameChar(),
   699                     names.empty);
   700         } while (lookupSynthetic(name, s) != null);
   701         return name;
   702     }
   704     /** Check whether synthetic symbols generated during lowering conflict
   705      *  with user-defined symbols.
   706      *
   707      *  @param translatedTrees lowered class trees
   708      */
   709     void checkConflicts(List<JCTree> translatedTrees) {
   710         for (JCTree t : translatedTrees) {
   711             t.accept(conflictsChecker);
   712         }
   713     }
   715     JCTree.Visitor conflictsChecker = new TreeScanner() {
   717         TypeSymbol currentClass;
   719         @Override
   720         public void visitMethodDef(JCMethodDecl that) {
   721             chk.checkConflicts(that.pos(), that.sym, currentClass);
   722             super.visitMethodDef(that);
   723         }
   725         @Override
   726         public void visitVarDef(JCVariableDecl that) {
   727             if (that.sym.owner.kind == TYP) {
   728                 chk.checkConflicts(that.pos(), that.sym, currentClass);
   729             }
   730             super.visitVarDef(that);
   731         }
   733         @Override
   734         public void visitClassDef(JCClassDecl that) {
   735             TypeSymbol prevCurrentClass = currentClass;
   736             currentClass = that.sym;
   737             try {
   738                 super.visitClassDef(that);
   739             }
   740             finally {
   741                 currentClass = prevCurrentClass;
   742             }
   743         }
   744     };
   746     /** Look up a synthetic name in a given scope.
   747      *  @param s            The scope.
   748      *  @param name         The name.
   749      */
   750     private Symbol lookupSynthetic(Name name, Scope s) {
   751         Symbol sym = s.lookup(name).sym;
   752         return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym;
   753     }
   755     /** Look up a method in a given scope.
   756      */
   757     private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) {
   758         return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.<Type>nil());
   759     }
   761     /** Look up a constructor.
   762      */
   763     private MethodSymbol lookupConstructor(DiagnosticPosition pos, Type qual, List<Type> args) {
   764         return rs.resolveInternalConstructor(pos, attrEnv, qual, args, null);
   765     }
   767     /** Look up a field.
   768      */
   769     private VarSymbol lookupField(DiagnosticPosition pos, Type qual, Name name) {
   770         return rs.resolveInternalField(pos, attrEnv, qual, name);
   771     }
   773     /** Anon inner classes are used as access constructor tags.
   774      * accessConstructorTag will use an existing anon class if one is available,
   775      * and synthethise a class (with makeEmptyClass) if one is not available.
   776      * However, there is a small possibility that an existing class will not
   777      * be generated as expected if it is inside a conditional with a constant
   778      * expression. If that is found to be the case, create an empty class tree here.
   779      */
   780     private void checkAccessConstructorTags() {
   781         for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) {
   782             ClassSymbol c = l.head;
   783             if (isTranslatedClassAvailable(c))
   784                 continue;
   785             // Create class definition tree.
   786             JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC,
   787                     c.outermostClass(), c.flatname, false);
   788             swapAccessConstructorTag(c, cdec.sym);
   789             translated.append(cdec);
   790         }
   791     }
   792     // where
   793     private boolean isTranslatedClassAvailable(ClassSymbol c) {
   794         for (JCTree tree: translated) {
   795             if (tree.hasTag(CLASSDEF)
   796                     && ((JCClassDecl) tree).sym == c) {
   797                 return true;
   798             }
   799         }
   800         return false;
   801     }
   803     void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) {
   804         for (MethodSymbol methodSymbol : accessConstrs.values()) {
   805             Assert.check(methodSymbol.type.hasTag(METHOD));
   806             MethodType oldMethodType =
   807                     (MethodType)methodSymbol.type;
   808             if (oldMethodType.argtypes.head.tsym == oldCTag)
   809                 methodSymbol.type =
   810                     types.createMethodTypeWithParameters(oldMethodType,
   811                         oldMethodType.getParameterTypes().tail
   812                             .prepend(newCTag.erasure(types)));
   813         }
   814     }
   816 /**************************************************************************
   817  * Access methods
   818  *************************************************************************/
   820     /** Access codes for dereferencing, assignment,
   821      *  and pre/post increment/decrement.
   822      *  Access codes for assignment operations are determined by method accessCode
   823      *  below.
   824      *
   825      *  All access codes for accesses to the current class are even.
   826      *  If a member of the superclass should be accessed instead (because
   827      *  access was via a qualified super), add one to the corresponding code
   828      *  for the current class, making the number odd.
   829      *  This numbering scheme is used by the backend to decide whether
   830      *  to issue an invokevirtual or invokespecial call.
   831      *
   832      *  @see Gen#visitSelect(JCFieldAccess tree)
   833      */
   834     private static final int
   835         DEREFcode = 0,
   836         ASSIGNcode = 2,
   837         PREINCcode = 4,
   838         PREDECcode = 6,
   839         POSTINCcode = 8,
   840         POSTDECcode = 10,
   841         FIRSTASGOPcode = 12;
   843     /** Number of access codes
   844      */
   845     private static final int NCODES = accessCode(ByteCodes.lushrl) + 2;
   847     /** A mapping from symbols to their access numbers.
   848      */
   849     private Map<Symbol,Integer> accessNums;
   851     /** A mapping from symbols to an array of access symbols, indexed by
   852      *  access code.
   853      */
   854     private Map<Symbol,MethodSymbol[]> accessSyms;
   856     /** A mapping from (constructor) symbols to access constructor symbols.
   857      */
   858     private Map<Symbol,MethodSymbol> accessConstrs;
   860     /** A list of all class symbols used for access constructor tags.
   861      */
   862     private List<ClassSymbol> accessConstrTags;
   864     /** A queue for all accessed symbols.
   865      */
   866     private ListBuffer<Symbol> accessed;
   868     /** Map bytecode of binary operation to access code of corresponding
   869      *  assignment operation. This is always an even number.
   870      */
   871     private static int accessCode(int bytecode) {
   872         if (ByteCodes.iadd <= bytecode && bytecode <= ByteCodes.lxor)
   873             return (bytecode - iadd) * 2 + FIRSTASGOPcode;
   874         else if (bytecode == ByteCodes.string_add)
   875             return (ByteCodes.lxor + 1 - iadd) * 2 + FIRSTASGOPcode;
   876         else if (ByteCodes.ishll <= bytecode && bytecode <= ByteCodes.lushrl)
   877             return (bytecode - ishll + ByteCodes.lxor + 2 - iadd) * 2 + FIRSTASGOPcode;
   878         else
   879             return -1;
   880     }
   882     /** return access code for identifier,
   883      *  @param tree     The tree representing the identifier use.
   884      *  @param enclOp   The closest enclosing operation node of tree,
   885      *                  null if tree is not a subtree of an operation.
   886      */
   887     private static int accessCode(JCTree tree, JCTree enclOp) {
   888         if (enclOp == null)
   889             return DEREFcode;
   890         else if (enclOp.hasTag(ASSIGN) &&
   891                  tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs))
   892             return ASSIGNcode;
   893         else if (enclOp.getTag().isIncOrDecUnaryOp() &&
   894                  tree == TreeInfo.skipParens(((JCUnary) enclOp).arg))
   895             return mapTagToUnaryOpCode(enclOp.getTag());
   896         else if (enclOp.getTag().isAssignop() &&
   897                  tree == TreeInfo.skipParens(((JCAssignOp) enclOp).lhs))
   898             return accessCode(((OperatorSymbol) ((JCAssignOp) enclOp).operator).opcode);
   899         else
   900             return DEREFcode;
   901     }
   903     /** Return binary operator that corresponds to given access code.
   904      */
   905     private OperatorSymbol binaryAccessOperator(int acode) {
   906         for (Scope.Entry e = syms.predefClass.members().elems;
   907              e != null;
   908              e = e.sibling) {
   909             if (e.sym instanceof OperatorSymbol) {
   910                 OperatorSymbol op = (OperatorSymbol)e.sym;
   911                 if (accessCode(op.opcode) == acode) return op;
   912             }
   913         }
   914         return null;
   915     }
   917     /** Return tree tag for assignment operation corresponding
   918      *  to given binary operator.
   919      */
   920     private static JCTree.Tag treeTag(OperatorSymbol operator) {
   921         switch (operator.opcode) {
   922         case ByteCodes.ior: case ByteCodes.lor:
   923             return BITOR_ASG;
   924         case ByteCodes.ixor: case ByteCodes.lxor:
   925             return BITXOR_ASG;
   926         case ByteCodes.iand: case ByteCodes.land:
   927             return BITAND_ASG;
   928         case ByteCodes.ishl: case ByteCodes.lshl:
   929         case ByteCodes.ishll: case ByteCodes.lshll:
   930             return SL_ASG;
   931         case ByteCodes.ishr: case ByteCodes.lshr:
   932         case ByteCodes.ishrl: case ByteCodes.lshrl:
   933             return SR_ASG;
   934         case ByteCodes.iushr: case ByteCodes.lushr:
   935         case ByteCodes.iushrl: case ByteCodes.lushrl:
   936             return USR_ASG;
   937         case ByteCodes.iadd: case ByteCodes.ladd:
   938         case ByteCodes.fadd: case ByteCodes.dadd:
   939         case ByteCodes.string_add:
   940             return PLUS_ASG;
   941         case ByteCodes.isub: case ByteCodes.lsub:
   942         case ByteCodes.fsub: case ByteCodes.dsub:
   943             return MINUS_ASG;
   944         case ByteCodes.imul: case ByteCodes.lmul:
   945         case ByteCodes.fmul: case ByteCodes.dmul:
   946             return MUL_ASG;
   947         case ByteCodes.idiv: case ByteCodes.ldiv:
   948         case ByteCodes.fdiv: case ByteCodes.ddiv:
   949             return DIV_ASG;
   950         case ByteCodes.imod: case ByteCodes.lmod:
   951         case ByteCodes.fmod: case ByteCodes.dmod:
   952             return MOD_ASG;
   953         default:
   954             throw new AssertionError();
   955         }
   956     }
   958     /** The name of the access method with number `anum' and access code `acode'.
   959      */
   960     Name accessName(int anum, int acode) {
   961         return names.fromString(
   962             "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10);
   963     }
   965     /** Return access symbol for a private or protected symbol from an inner class.
   966      *  @param sym        The accessed private symbol.
   967      *  @param tree       The accessing tree.
   968      *  @param enclOp     The closest enclosing operation node of tree,
   969      *                    null if tree is not a subtree of an operation.
   970      *  @param protAccess Is access to a protected symbol in another
   971      *                    package?
   972      *  @param refSuper   Is access via a (qualified) C.super?
   973      */
   974     MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp,
   975                               boolean protAccess, boolean refSuper) {
   976         ClassSymbol accOwner = refSuper && protAccess
   977             // For access via qualified super (T.super.x), place the
   978             // access symbol on T.
   979             ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym
   980             // Otherwise pretend that the owner of an accessed
   981             // protected symbol is the enclosing class of the current
   982             // class which is a subclass of the symbol's owner.
   983             : accessClass(sym, protAccess, tree);
   985         Symbol vsym = sym;
   986         if (sym.owner != accOwner) {
   987             vsym = sym.clone(accOwner);
   988             actualSymbols.put(vsym, sym);
   989         }
   991         Integer anum              // The access number of the access method.
   992             = accessNums.get(vsym);
   993         if (anum == null) {
   994             anum = accessed.length();
   995             accessNums.put(vsym, anum);
   996             accessSyms.put(vsym, new MethodSymbol[NCODES]);
   997             accessed.append(vsym);
   998             // System.out.println("accessing " + vsym + " in " + vsym.location());
   999         }
  1001         int acode;                // The access code of the access method.
  1002         List<Type> argtypes;      // The argument types of the access method.
  1003         Type restype;             // The result type of the access method.
  1004         List<Type> thrown;        // The thrown exceptions of the access method.
  1005         switch (vsym.kind) {
  1006         case VAR:
  1007             acode = accessCode(tree, enclOp);
  1008             if (acode >= FIRSTASGOPcode) {
  1009                 OperatorSymbol operator = binaryAccessOperator(acode);
  1010                 if (operator.opcode == string_add)
  1011                     argtypes = List.of(syms.objectType);
  1012                 else
  1013                     argtypes = operator.type.getParameterTypes().tail;
  1014             } else if (acode == ASSIGNcode)
  1015                 argtypes = List.of(vsym.erasure(types));
  1016             else
  1017                 argtypes = List.nil();
  1018             restype = vsym.erasure(types);
  1019             thrown = List.nil();
  1020             break;
  1021         case MTH:
  1022             acode = DEREFcode;
  1023             argtypes = vsym.erasure(types).getParameterTypes();
  1024             restype = vsym.erasure(types).getReturnType();
  1025             thrown = vsym.type.getThrownTypes();
  1026             break;
  1027         default:
  1028             throw new AssertionError();
  1031         // For references via qualified super, increment acode by one,
  1032         // making it odd.
  1033         if (protAccess && refSuper) acode++;
  1035         // Instance access methods get instance as first parameter.
  1036         // For protected symbols this needs to be the instance as a member
  1037         // of the type containing the accessed symbol, not the class
  1038         // containing the access method.
  1039         if ((vsym.flags() & STATIC) == 0) {
  1040             argtypes = argtypes.prepend(vsym.owner.erasure(types));
  1042         MethodSymbol[] accessors = accessSyms.get(vsym);
  1043         MethodSymbol accessor = accessors[acode];
  1044         if (accessor == null) {
  1045             accessor = new MethodSymbol(
  1046                 STATIC | SYNTHETIC,
  1047                 accessName(anum.intValue(), acode),
  1048                 new MethodType(argtypes, restype, thrown, syms.methodClass),
  1049                 accOwner);
  1050             enterSynthetic(tree.pos(), accessor, accOwner.members());
  1051             accessors[acode] = accessor;
  1053         return accessor;
  1056     /** The qualifier to be used for accessing a symbol in an outer class.
  1057      *  This is either C.sym or C.this.sym, depending on whether or not
  1058      *  sym is static.
  1059      *  @param sym   The accessed symbol.
  1060      */
  1061     JCExpression accessBase(DiagnosticPosition pos, Symbol sym) {
  1062         return (sym.flags() & STATIC) != 0
  1063             ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner))
  1064             : makeOwnerThis(pos, sym, true);
  1067     /** Do we need an access method to reference private symbol?
  1068      */
  1069     boolean needsPrivateAccess(Symbol sym) {
  1070         if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) {
  1071             return false;
  1072         } else if (sym.name == names.init && sym.owner.isLocal()) {
  1073             // private constructor in local class: relax protection
  1074             sym.flags_field &= ~PRIVATE;
  1075             return false;
  1076         } else {
  1077             return true;
  1081     /** Do we need an access method to reference symbol in other package?
  1082      */
  1083     boolean needsProtectedAccess(Symbol sym, JCTree tree) {
  1084         if ((sym.flags() & PROTECTED) == 0 ||
  1085             sym.owner.owner == currentClass.owner || // fast special case
  1086             sym.packge() == currentClass.packge())
  1087             return false;
  1088         if (!currentClass.isSubClass(sym.owner, types))
  1089             return true;
  1090         if ((sym.flags() & STATIC) != 0 ||
  1091             !tree.hasTag(SELECT) ||
  1092             TreeInfo.name(((JCFieldAccess) tree).selected) == names._super)
  1093             return false;
  1094         return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types);
  1097     /** The class in which an access method for given symbol goes.
  1098      *  @param sym        The access symbol
  1099      *  @param protAccess Is access to a protected symbol in another
  1100      *                    package?
  1101      */
  1102     ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) {
  1103         if (protAccess) {
  1104             Symbol qualifier = null;
  1105             ClassSymbol c = currentClass;
  1106             if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) {
  1107                 qualifier = ((JCFieldAccess) tree).selected.type.tsym;
  1108                 while (!qualifier.isSubClass(c, types)) {
  1109                     c = c.owner.enclClass();
  1111                 return c;
  1112             } else {
  1113                 while (!c.isSubClass(sym.owner, types)) {
  1114                     c = c.owner.enclClass();
  1117             return c;
  1118         } else {
  1119             // the symbol is private
  1120             return sym.owner.enclClass();
  1124     private void addPrunedInfo(JCTree tree) {
  1125         List<JCTree> infoList = prunedTree.get(currentClass);
  1126         infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree);
  1127         prunedTree.put(currentClass, infoList);
  1130     /** Ensure that identifier is accessible, return tree accessing the identifier.
  1131      *  @param sym      The accessed symbol.
  1132      *  @param tree     The tree referring to the symbol.
  1133      *  @param enclOp   The closest enclosing operation node of tree,
  1134      *                  null if tree is not a subtree of an operation.
  1135      *  @param refSuper Is access via a (qualified) C.super?
  1136      */
  1137     JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) {
  1138         // Access a free variable via its proxy, or its proxy's proxy
  1139         while (sym.kind == VAR && sym.owner.kind == MTH &&
  1140             sym.owner.enclClass() != currentClass) {
  1141             // A constant is replaced by its constant value.
  1142             Object cv = ((VarSymbol)sym).getConstValue();
  1143             if (cv != null) {
  1144                 make.at(tree.pos);
  1145                 return makeLit(sym.type, cv);
  1147             // Otherwise replace the variable by its proxy.
  1148             sym = proxies.lookup(proxyName(sym.name)).sym;
  1149             Assert.check(sym != null && (sym.flags_field & FINAL) != 0);
  1150             tree = make.at(tree.pos).Ident(sym);
  1152         JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null;
  1153         switch (sym.kind) {
  1154         case TYP:
  1155             if (sym.owner.kind != PCK) {
  1156                 // Convert type idents to
  1157                 // <flat name> or <package name> . <flat name>
  1158                 Name flatname = Convert.shortName(sym.flatName());
  1159                 while (base != null &&
  1160                        TreeInfo.symbol(base) != null &&
  1161                        TreeInfo.symbol(base).kind != PCK) {
  1162                     base = (base.hasTag(SELECT))
  1163                         ? ((JCFieldAccess) base).selected
  1164                         : null;
  1166                 if (tree.hasTag(IDENT)) {
  1167                     ((JCIdent) tree).name = flatname;
  1168                 } else if (base == null) {
  1169                     tree = make.at(tree.pos).Ident(sym);
  1170                     ((JCIdent) tree).name = flatname;
  1171                 } else {
  1172                     ((JCFieldAccess) tree).selected = base;
  1173                     ((JCFieldAccess) tree).name = flatname;
  1176             break;
  1177         case MTH: case VAR:
  1178             if (sym.owner.kind == TYP) {
  1180                 // Access methods are required for
  1181                 //  - private members,
  1182                 //  - protected members in a superclass of an
  1183                 //    enclosing class contained in another package.
  1184                 //  - all non-private members accessed via a qualified super.
  1185                 boolean protAccess = refSuper && !needsPrivateAccess(sym)
  1186                     || needsProtectedAccess(sym, tree);
  1187                 boolean accReq = protAccess || needsPrivateAccess(sym);
  1189                 // A base has to be supplied for
  1190                 //  - simple identifiers accessing variables in outer classes.
  1191                 boolean baseReq =
  1192                     base == null &&
  1193                     sym.owner != syms.predefClass &&
  1194                     !sym.isMemberOf(currentClass, types);
  1196                 if (accReq || baseReq) {
  1197                     make.at(tree.pos);
  1199                     // Constants are replaced by their constant value.
  1200                     if (sym.kind == VAR) {
  1201                         Object cv = ((VarSymbol)sym).getConstValue();
  1202                         if (cv != null) {
  1203                             addPrunedInfo(tree);
  1204                             return makeLit(sym.type, cv);
  1208                     // Private variables and methods are replaced by calls
  1209                     // to their access methods.
  1210                     if (accReq) {
  1211                         List<JCExpression> args = List.nil();
  1212                         if ((sym.flags() & STATIC) == 0) {
  1213                             // Instance access methods get instance
  1214                             // as first parameter.
  1215                             if (base == null)
  1216                                 base = makeOwnerThis(tree.pos(), sym, true);
  1217                             args = args.prepend(base);
  1218                             base = null;   // so we don't duplicate code
  1220                         Symbol access = accessSymbol(sym, tree,
  1221                                                      enclOp, protAccess,
  1222                                                      refSuper);
  1223                         JCExpression receiver = make.Select(
  1224                             base != null ? base : make.QualIdent(access.owner),
  1225                             access);
  1226                         return make.App(receiver, args);
  1228                     // Other accesses to members of outer classes get a
  1229                     // qualifier.
  1230                     } else if (baseReq) {
  1231                         return make.at(tree.pos).Select(
  1232                             accessBase(tree.pos(), sym), sym).setType(tree.type);
  1235             } else if (sym.owner.kind == MTH && lambdaTranslationMap != null) {
  1236                 //sym is a local variable - check the lambda translation map to
  1237                 //see if sym has been translated to something else in the current
  1238                 //scope (by LambdaToMethod)
  1239                 Symbol translatedSym = lambdaTranslationMap.get(sym);
  1240                 if (translatedSym != null) {
  1241                     tree = make.at(tree.pos).Ident(translatedSym);
  1245         return tree;
  1248     /** Ensure that identifier is accessible, return tree accessing the identifier.
  1249      *  @param tree     The identifier tree.
  1250      */
  1251     JCExpression access(JCExpression tree) {
  1252         Symbol sym = TreeInfo.symbol(tree);
  1253         return sym == null ? tree : access(sym, tree, null, false);
  1256     /** Return access constructor for a private constructor,
  1257      *  or the constructor itself, if no access constructor is needed.
  1258      *  @param pos       The position to report diagnostics, if any.
  1259      *  @param constr    The private constructor.
  1260      */
  1261     Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) {
  1262         if (needsPrivateAccess(constr)) {
  1263             ClassSymbol accOwner = constr.owner.enclClass();
  1264             MethodSymbol aconstr = accessConstrs.get(constr);
  1265             if (aconstr == null) {
  1266                 List<Type> argtypes = constr.type.getParameterTypes();
  1267                 if ((accOwner.flags_field & ENUM) != 0)
  1268                     argtypes = argtypes
  1269                         .prepend(syms.intType)
  1270                         .prepend(syms.stringType);
  1271                 aconstr = new MethodSymbol(
  1272                     SYNTHETIC,
  1273                     names.init,
  1274                     new MethodType(
  1275                         argtypes.append(
  1276                             accessConstructorTag().erasure(types)),
  1277                         constr.type.getReturnType(),
  1278                         constr.type.getThrownTypes(),
  1279                         syms.methodClass),
  1280                     accOwner);
  1281                 enterSynthetic(pos, aconstr, accOwner.members());
  1282                 accessConstrs.put(constr, aconstr);
  1283                 accessed.append(constr);
  1285             return aconstr;
  1286         } else {
  1287             return constr;
  1291     /** Return an anonymous class nested in this toplevel class.
  1292      */
  1293     ClassSymbol accessConstructorTag() {
  1294         ClassSymbol topClass = currentClass.outermostClass();
  1295         Name flatname = names.fromString("" + topClass.getQualifiedName() +
  1296                                          target.syntheticNameChar() +
  1297                                          "1");
  1298         ClassSymbol ctag = chk.compiled.get(flatname);
  1299         if (ctag == null)
  1300             ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym;
  1301         // keep a record of all tags, to verify that all are generated as required
  1302         accessConstrTags = accessConstrTags.prepend(ctag);
  1303         return ctag;
  1306     /** Add all required access methods for a private symbol to enclosing class.
  1307      *  @param sym       The symbol.
  1308      */
  1309     void makeAccessible(Symbol sym) {
  1310         JCClassDecl cdef = classDef(sym.owner.enclClass());
  1311         if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner);
  1312         if (sym.name == names.init) {
  1313             cdef.defs = cdef.defs.prepend(
  1314                 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym)));
  1315         } else {
  1316             MethodSymbol[] accessors = accessSyms.get(sym);
  1317             for (int i = 0; i < NCODES; i++) {
  1318                 if (accessors[i] != null)
  1319                     cdef.defs = cdef.defs.prepend(
  1320                         accessDef(cdef.pos, sym, accessors[i], i));
  1325     /** Maps unary operator integer codes to JCTree.Tag objects
  1326      *  @param unaryOpCode the unary operator code
  1327      */
  1328     private static Tag mapUnaryOpCodeToTag(int unaryOpCode){
  1329         switch (unaryOpCode){
  1330             case PREINCcode:
  1331                 return PREINC;
  1332             case PREDECcode:
  1333                 return PREDEC;
  1334             case POSTINCcode:
  1335                 return POSTINC;
  1336             case POSTDECcode:
  1337                 return POSTDEC;
  1338             default:
  1339                 return NO_TAG;
  1343     /** Maps JCTree.Tag objects to unary operator integer codes
  1344      *  @param tag the JCTree.Tag
  1345      */
  1346     private static int mapTagToUnaryOpCode(Tag tag){
  1347         switch (tag){
  1348             case PREINC:
  1349                 return PREINCcode;
  1350             case PREDEC:
  1351                 return PREDECcode;
  1352             case POSTINC:
  1353                 return POSTINCcode;
  1354             case POSTDEC:
  1355                 return POSTDECcode;
  1356             default:
  1357                 return -1;
  1361     /** Construct definition of an access method.
  1362      *  @param pos        The source code position of the definition.
  1363      *  @param vsym       The private or protected symbol.
  1364      *  @param accessor   The access method for the symbol.
  1365      *  @param acode      The access code.
  1366      */
  1367     JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) {
  1368 //      System.err.println("access " + vsym + " with " + accessor);//DEBUG
  1369         currentClass = vsym.owner.enclClass();
  1370         make.at(pos);
  1371         JCMethodDecl md = make.MethodDef(accessor, null);
  1373         // Find actual symbol
  1374         Symbol sym = actualSymbols.get(vsym);
  1375         if (sym == null) sym = vsym;
  1377         JCExpression ref;           // The tree referencing the private symbol.
  1378         List<JCExpression> args;    // Any additional arguments to be passed along.
  1379         if ((sym.flags() & STATIC) != 0) {
  1380             ref = make.Ident(sym);
  1381             args = make.Idents(md.params);
  1382         } else {
  1383             JCExpression site = make.Ident(md.params.head);
  1384             if (acode % 2 != 0) {
  1385                 //odd access codes represent qualified super accesses - need to
  1386                 //emit reference to the direct superclass, even if the refered
  1387                 //member is from an indirect superclass (JLS 13.1)
  1388                 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type)));
  1390             ref = make.Select(site, sym);
  1391             args = make.Idents(md.params.tail);
  1393         JCStatement stat;          // The statement accessing the private symbol.
  1394         if (sym.kind == VAR) {
  1395             // Normalize out all odd access codes by taking floor modulo 2:
  1396             int acode1 = acode - (acode & 1);
  1398             JCExpression expr;      // The access method's return value.
  1399             switch (acode1) {
  1400             case DEREFcode:
  1401                 expr = ref;
  1402                 break;
  1403             case ASSIGNcode:
  1404                 expr = make.Assign(ref, args.head);
  1405                 break;
  1406             case PREINCcode: case POSTINCcode: case PREDECcode: case POSTDECcode:
  1407                 expr = makeUnary(mapUnaryOpCodeToTag(acode1), ref);
  1408                 break;
  1409             default:
  1410                 expr = make.Assignop(
  1411                     treeTag(binaryAccessOperator(acode1)), ref, args.head);
  1412                 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1);
  1414             stat = make.Return(expr.setType(sym.type));
  1415         } else {
  1416             stat = make.Call(make.App(ref, args));
  1418         md.body = make.Block(0, List.of(stat));
  1420         // Make sure all parameters, result types and thrown exceptions
  1421         // are accessible.
  1422         for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail)
  1423             l.head.vartype = access(l.head.vartype);
  1424         md.restype = access(md.restype);
  1425         for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail)
  1426             l.head = access(l.head);
  1428         return md;
  1431     /** Construct definition of an access constructor.
  1432      *  @param pos        The source code position of the definition.
  1433      *  @param constr     The private constructor.
  1434      *  @param accessor   The access method for the constructor.
  1435      */
  1436     JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) {
  1437         make.at(pos);
  1438         JCMethodDecl md = make.MethodDef(accessor,
  1439                                       accessor.externalType(types),
  1440                                       null);
  1441         JCIdent callee = make.Ident(names._this);
  1442         callee.sym = constr;
  1443         callee.type = constr.type;
  1444         md.body =
  1445             make.Block(0, List.<JCStatement>of(
  1446                 make.Call(
  1447                     make.App(
  1448                         callee,
  1449                         make.Idents(md.params.reverse().tail.reverse())))));
  1450         return md;
  1453 /**************************************************************************
  1454  * Free variables proxies and this$n
  1455  *************************************************************************/
  1457     /** A scope containing all free variable proxies for currently translated
  1458      *  class, as well as its this$n symbol (if needed).
  1459      *  Proxy scopes are nested in the same way classes are.
  1460      *  Inside a constructor, proxies and any this$n symbol are duplicated
  1461      *  in an additional innermost scope, where they represent the constructor
  1462      *  parameters.
  1463      */
  1464     Scope proxies;
  1466     /** A scope containing all unnamed resource variables/saved
  1467      *  exception variables for translated TWR blocks
  1468      */
  1469     Scope twrVars;
  1471     /** A stack containing the this$n field of the currently translated
  1472      *  classes (if needed) in innermost first order.
  1473      *  Inside a constructor, proxies and any this$n symbol are duplicated
  1474      *  in an additional innermost scope, where they represent the constructor
  1475      *  parameters.
  1476      */
  1477     List<VarSymbol> outerThisStack;
  1479     /** The name of a free variable proxy.
  1480      */
  1481     Name proxyName(Name name) {
  1482         return names.fromString("val" + target.syntheticNameChar() + name);
  1485     /** Proxy definitions for all free variables in given list, in reverse order.
  1486      *  @param pos        The source code position of the definition.
  1487      *  @param freevars   The free variables.
  1488      *  @param owner      The class in which the definitions go.
  1489      */
  1490     List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) {
  1491         return freevarDefs(pos, freevars, owner, 0);
  1494     List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner,
  1495             long additionalFlags) {
  1496         long flags = FINAL | SYNTHETIC | additionalFlags;
  1497         if (owner.kind == TYP &&
  1498             target.usePrivateSyntheticFields())
  1499             flags |= PRIVATE;
  1500         List<JCVariableDecl> defs = List.nil();
  1501         for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) {
  1502             VarSymbol v = l.head;
  1503             VarSymbol proxy = new VarSymbol(
  1504                 flags, proxyName(v.name), v.erasure(types), owner);
  1505             proxies.enter(proxy);
  1506             JCVariableDecl vd = make.at(pos).VarDef(proxy, null);
  1507             vd.vartype = access(vd.vartype);
  1508             defs = defs.prepend(vd);
  1510         return defs;
  1513     /** The name of a this$n field
  1514      *  @param type   The class referenced by the this$n field
  1515      */
  1516     Name outerThisName(Type type, Symbol owner) {
  1517         Type t = type.getEnclosingType();
  1518         int nestingLevel = 0;
  1519         while (t.hasTag(CLASS)) {
  1520             t = t.getEnclosingType();
  1521             nestingLevel++;
  1523         Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel);
  1524         while (owner.kind == TYP && ((ClassSymbol)owner).members().lookup(result).scope != null)
  1525             result = names.fromString(result.toString() + target.syntheticNameChar());
  1526         return result;
  1529     private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) {
  1530         if (owner.kind == TYP &&
  1531             target.usePrivateSyntheticFields())
  1532             flags |= PRIVATE;
  1533         Type target = types.erasure(owner.enclClass().type.getEnclosingType());
  1534         VarSymbol outerThis =
  1535             new VarSymbol(flags, outerThisName(target, owner), target, owner);
  1536         outerThisStack = outerThisStack.prepend(outerThis);
  1537         return outerThis;
  1540     private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) {
  1541         JCVariableDecl vd = make.at(pos).VarDef(sym, null);
  1542         vd.vartype = access(vd.vartype);
  1543         return vd;
  1546     /** Definition for this$n field.
  1547      *  @param pos        The source code position of the definition.
  1548      *  @param owner      The method in which the definition goes.
  1549      */
  1550     JCVariableDecl outerThisDef(int pos, MethodSymbol owner) {
  1551         ClassSymbol c = owner.enclClass();
  1552         boolean isMandated =
  1553             // Anonymous constructors
  1554             (owner.isConstructor() && owner.isAnonymous()) ||
  1555             // Constructors of non-private inner member classes
  1556             (owner.isConstructor() && c.isInner() &&
  1557              !c.isPrivate() && !c.isStatic());
  1558         long flags =
  1559             FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER;
  1560         VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags);
  1561         owner.extraParams = owner.extraParams.prepend(outerThis);
  1562         return makeOuterThisVarDecl(pos, outerThis);
  1565     /** Definition for this$n field.
  1566      *  @param pos        The source code position of the definition.
  1567      *  @param owner      The class in which the definition goes.
  1568      */
  1569     JCVariableDecl outerThisDef(int pos, ClassSymbol owner) {
  1570         VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC);
  1571         return makeOuterThisVarDecl(pos, outerThis);
  1574     /** Return a list of trees that load the free variables in given list,
  1575      *  in reverse order.
  1576      *  @param pos          The source code position to be used for the trees.
  1577      *  @param freevars     The list of free variables.
  1578      */
  1579     List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) {
  1580         List<JCExpression> args = List.nil();
  1581         for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail)
  1582             args = args.prepend(loadFreevar(pos, l.head));
  1583         return args;
  1585 //where
  1586         JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) {
  1587             return access(v, make.at(pos).Ident(v), null, false);
  1590     /** Construct a tree simulating the expression {@code C.this}.
  1591      *  @param pos           The source code position to be used for the tree.
  1592      *  @param c             The qualifier class.
  1593      */
  1594     JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) {
  1595         if (currentClass == c) {
  1596             // in this case, `this' works fine
  1597             return make.at(pos).This(c.erasure(types));
  1598         } else {
  1599             // need to go via this$n
  1600             return makeOuterThis(pos, c);
  1604     /**
  1605      * Optionally replace a try statement with the desugaring of a
  1606      * try-with-resources statement.  The canonical desugaring of
  1608      * try ResourceSpecification
  1609      *   Block
  1611      * is
  1613      * {
  1614      *   final VariableModifiers_minus_final R #resource = Expression;
  1615      *   Throwable #primaryException = null;
  1617      *   try ResourceSpecificationtail
  1618      *     Block
  1619      *   catch (Throwable #t) {
  1620      *     #primaryException = t;
  1621      *     throw #t;
  1622      *   } finally {
  1623      *     if (#resource != null) {
  1624      *       if (#primaryException != null) {
  1625      *         try {
  1626      *           #resource.close();
  1627      *         } catch(Throwable #suppressedException) {
  1628      *           #primaryException.addSuppressed(#suppressedException);
  1629      *         }
  1630      *       } else {
  1631      *         #resource.close();
  1632      *       }
  1633      *     }
  1634      *   }
  1636      * @param tree  The try statement to inspect.
  1637      * @return A a desugared try-with-resources tree, or the original
  1638      * try block if there are no resources to manage.
  1639      */
  1640     JCTree makeTwrTry(JCTry tree) {
  1641         make_at(tree.pos());
  1642         twrVars = twrVars.dup();
  1643         JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body,
  1644                 tree.finallyCanCompleteNormally, 0);
  1645         if (tree.catchers.isEmpty() && tree.finalizer == null)
  1646             result = translate(twrBlock);
  1647         else
  1648             result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer));
  1649         twrVars = twrVars.leave();
  1650         return result;
  1653     private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block,
  1654             boolean finallyCanCompleteNormally, int depth) {
  1655         if (resources.isEmpty())
  1656             return block;
  1658         // Add resource declaration or expression to block statements
  1659         ListBuffer<JCStatement> stats = new ListBuffer<JCStatement>();
  1660         JCTree resource = resources.head;
  1661         JCExpression expr = null;
  1662         if (resource instanceof JCVariableDecl) {
  1663             JCVariableDecl var = (JCVariableDecl) resource;
  1664             expr = make.Ident(var.sym).setType(resource.type);
  1665             stats.add(var);
  1666         } else {
  1667             Assert.check(resource instanceof JCExpression);
  1668             VarSymbol syntheticTwrVar =
  1669             new VarSymbol(SYNTHETIC | FINAL,
  1670                           makeSyntheticName(names.fromString("twrVar" +
  1671                                            depth), twrVars),
  1672                           (resource.type.hasTag(BOT)) ?
  1673                           syms.autoCloseableType : resource.type,
  1674                           currentMethodSym);
  1675             twrVars.enter(syntheticTwrVar);
  1676             JCVariableDecl syntheticTwrVarDecl =
  1677                 make.VarDef(syntheticTwrVar, (JCExpression)resource);
  1678             expr = (JCExpression)make.Ident(syntheticTwrVar);
  1679             stats.add(syntheticTwrVarDecl);
  1682         // Add primaryException declaration
  1683         VarSymbol primaryException =
  1684             new VarSymbol(SYNTHETIC,
  1685                           makeSyntheticName(names.fromString("primaryException" +
  1686                           depth), twrVars),
  1687                           syms.throwableType,
  1688                           currentMethodSym);
  1689         twrVars.enter(primaryException);
  1690         JCVariableDecl primaryExceptionTreeDecl = make.VarDef(primaryException, makeNull());
  1691         stats.add(primaryExceptionTreeDecl);
  1693         // Create catch clause that saves exception and then rethrows it
  1694         VarSymbol param =
  1695             new VarSymbol(FINAL|SYNTHETIC,
  1696                           names.fromString("t" +
  1697                                            target.syntheticNameChar()),
  1698                           syms.throwableType,
  1699                           currentMethodSym);
  1700         JCVariableDecl paramTree = make.VarDef(param, null);
  1701         JCStatement assign = make.Assignment(primaryException, make.Ident(param));
  1702         JCStatement rethrowStat = make.Throw(make.Ident(param));
  1703         JCBlock catchBlock = make.Block(0L, List.<JCStatement>of(assign, rethrowStat));
  1704         JCCatch catchClause = make.Catch(paramTree, catchBlock);
  1706         int oldPos = make.pos;
  1707         make.at(TreeInfo.endPos(block));
  1708         JCBlock finallyClause = makeTwrFinallyClause(primaryException, expr);
  1709         make.at(oldPos);
  1710         JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block,
  1711                                     finallyCanCompleteNormally, depth + 1),
  1712                                   List.<JCCatch>of(catchClause),
  1713                                   finallyClause);
  1714         outerTry.finallyCanCompleteNormally = finallyCanCompleteNormally;
  1715         stats.add(outerTry);
  1716         JCBlock newBlock = make.Block(0L, stats.toList());
  1717         return newBlock;
  1720     private JCBlock makeTwrFinallyClause(Symbol primaryException, JCExpression resource) {
  1721         // primaryException.addSuppressed(catchException);
  1722         VarSymbol catchException =
  1723             new VarSymbol(SYNTHETIC, make.paramName(2),
  1724                           syms.throwableType,
  1725                           currentMethodSym);
  1726         JCStatement addSuppressionStatement =
  1727             make.Exec(makeCall(make.Ident(primaryException),
  1728                                names.addSuppressed,
  1729                                List.<JCExpression>of(make.Ident(catchException))));
  1731         // try { resource.close(); } catch (e) { primaryException.addSuppressed(e); }
  1732         JCBlock tryBlock =
  1733             make.Block(0L, List.<JCStatement>of(makeResourceCloseInvocation(resource)));
  1734         JCVariableDecl catchExceptionDecl = make.VarDef(catchException, null);
  1735         JCBlock catchBlock = make.Block(0L, List.<JCStatement>of(addSuppressionStatement));
  1736         List<JCCatch> catchClauses = List.<JCCatch>of(make.Catch(catchExceptionDecl, catchBlock));
  1737         JCTry tryTree = make.Try(tryBlock, catchClauses, null);
  1738         tryTree.finallyCanCompleteNormally = true;
  1740         // if (primaryException != null) {try...} else resourceClose;
  1741         JCIf closeIfStatement = make.If(makeNonNullCheck(make.Ident(primaryException)),
  1742                                         tryTree,
  1743                                         makeResourceCloseInvocation(resource));
  1745         // if (#resource != null) { if (primaryException ...  }
  1746         return make.Block(0L,
  1747                           List.<JCStatement>of(make.If(makeNonNullCheck(resource),
  1748                                                        closeIfStatement,
  1749                                                        null)));
  1752     private JCStatement makeResourceCloseInvocation(JCExpression resource) {
  1753         // convert to AutoCloseable if needed
  1754         if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) {
  1755             resource = (JCExpression) convert(resource, syms.autoCloseableType);
  1758         // create resource.close() method invocation
  1759         JCExpression resourceClose = makeCall(resource,
  1760                                               names.close,
  1761                                               List.<JCExpression>nil());
  1762         return make.Exec(resourceClose);
  1765     private JCExpression makeNonNullCheck(JCExpression expression) {
  1766         return makeBinary(NE, expression, makeNull());
  1769     /** Construct a tree that represents the outer instance
  1770      *  {@code C.this}. Never pick the current `this'.
  1771      *  @param pos           The source code position to be used for the tree.
  1772      *  @param c             The qualifier class.
  1773      */
  1774     JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) {
  1775         List<VarSymbol> ots = outerThisStack;
  1776         if (ots.isEmpty()) {
  1777             log.error(pos, "no.encl.instance.of.type.in.scope", c);
  1778             Assert.error();
  1779             return makeNull();
  1781         VarSymbol ot = ots.head;
  1782         JCExpression tree = access(make.at(pos).Ident(ot));
  1783         TypeSymbol otc = ot.type.tsym;
  1784         while (otc != c) {
  1785             do {
  1786                 ots = ots.tail;
  1787                 if (ots.isEmpty()) {
  1788                     log.error(pos,
  1789                               "no.encl.instance.of.type.in.scope",
  1790                               c);
  1791                     Assert.error(); // should have been caught in Attr
  1792                     return tree;
  1794                 ot = ots.head;
  1795             } while (ot.owner != otc);
  1796             if (otc.owner.kind != PCK && !otc.hasOuterInstance()) {
  1797                 chk.earlyRefError(pos, c);
  1798                 Assert.error(); // should have been caught in Attr
  1799                 return makeNull();
  1801             tree = access(make.at(pos).Select(tree, ot));
  1802             otc = ot.type.tsym;
  1804         return tree;
  1807     /** Construct a tree that represents the closest outer instance
  1808      *  {@code C.this} such that the given symbol is a member of C.
  1809      *  @param pos           The source code position to be used for the tree.
  1810      *  @param sym           The accessed symbol.
  1811      *  @param preciseMatch  should we accept a type that is a subtype of
  1812      *                       sym's owner, even if it doesn't contain sym
  1813      *                       due to hiding, overriding, or non-inheritance
  1814      *                       due to protection?
  1815      */
  1816     JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
  1817         Symbol c = sym.owner;
  1818         if (preciseMatch ? sym.isMemberOf(currentClass, types)
  1819                          : currentClass.isSubClass(sym.owner, types)) {
  1820             // in this case, `this' works fine
  1821             return make.at(pos).This(c.erasure(types));
  1822         } else {
  1823             // need to go via this$n
  1824             return makeOwnerThisN(pos, sym, preciseMatch);
  1828     /**
  1829      * Similar to makeOwnerThis but will never pick "this".
  1830      */
  1831     JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
  1832         Symbol c = sym.owner;
  1833         List<VarSymbol> ots = outerThisStack;
  1834         if (ots.isEmpty()) {
  1835             log.error(pos, "no.encl.instance.of.type.in.scope", c);
  1836             Assert.error();
  1837             return makeNull();
  1839         VarSymbol ot = ots.head;
  1840         JCExpression tree = access(make.at(pos).Ident(ot));
  1841         TypeSymbol otc = ot.type.tsym;
  1842         while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) {
  1843             do {
  1844                 ots = ots.tail;
  1845                 if (ots.isEmpty()) {
  1846                     log.error(pos,
  1847                         "no.encl.instance.of.type.in.scope",
  1848                         c);
  1849                     Assert.error();
  1850                     return tree;
  1852                 ot = ots.head;
  1853             } while (ot.owner != otc);
  1854             tree = access(make.at(pos).Select(tree, ot));
  1855             otc = ot.type.tsym;
  1857         return tree;
  1860     /** Return tree simulating the assignment {@code this.name = name}, where
  1861      *  name is the name of a free variable.
  1862      */
  1863     JCStatement initField(int pos, Name name) {
  1864         Scope.Entry e = proxies.lookup(name);
  1865         Symbol rhs = e.sym;
  1866         Assert.check(rhs.owner.kind == MTH);
  1867         Symbol lhs = e.next().sym;
  1868         Assert.check(rhs.owner.owner == lhs.owner);
  1869         make.at(pos);
  1870         return
  1871             make.Exec(
  1872                 make.Assign(
  1873                     make.Select(make.This(lhs.owner.erasure(types)), lhs),
  1874                     make.Ident(rhs)).setType(lhs.erasure(types)));
  1877     /** Return tree simulating the assignment {@code this.this$n = this$n}.
  1878      */
  1879     JCStatement initOuterThis(int pos) {
  1880         VarSymbol rhs = outerThisStack.head;
  1881         Assert.check(rhs.owner.kind == MTH);
  1882         VarSymbol lhs = outerThisStack.tail.head;
  1883         Assert.check(rhs.owner.owner == lhs.owner);
  1884         make.at(pos);
  1885         return
  1886             make.Exec(
  1887                 make.Assign(
  1888                     make.Select(make.This(lhs.owner.erasure(types)), lhs),
  1889                     make.Ident(rhs)).setType(lhs.erasure(types)));
  1892 /**************************************************************************
  1893  * Code for .class
  1894  *************************************************************************/
  1896     /** Return the symbol of a class to contain a cache of
  1897      *  compiler-generated statics such as class$ and the
  1898      *  $assertionsDisabled flag.  We create an anonymous nested class
  1899      *  (unless one already exists) and return its symbol.  However,
  1900      *  for backward compatibility in 1.4 and earlier we use the
  1901      *  top-level class itself.
  1902      */
  1903     private ClassSymbol outerCacheClass() {
  1904         ClassSymbol clazz = outermostClassDef.sym;
  1905         if ((clazz.flags() & INTERFACE) == 0 &&
  1906             !target.useInnerCacheClass()) return clazz;
  1907         Scope s = clazz.members();
  1908         for (Scope.Entry e = s.elems; e != null; e = e.sibling)
  1909             if (e.sym.kind == TYP &&
  1910                 e.sym.name == names.empty &&
  1911                 (e.sym.flags() & INTERFACE) == 0) return (ClassSymbol) e.sym;
  1912         return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym;
  1915     /** Return symbol for "class$" method. If there is no method definition
  1916      *  for class$, construct one as follows:
  1918      *    class class$(String x0) {
  1919      *      try {
  1920      *        return Class.forName(x0);
  1921      *      } catch (ClassNotFoundException x1) {
  1922      *        throw new NoClassDefFoundError(x1.getMessage());
  1923      *      }
  1924      *    }
  1925      */
  1926     private MethodSymbol classDollarSym(DiagnosticPosition pos) {
  1927         ClassSymbol outerCacheClass = outerCacheClass();
  1928         MethodSymbol classDollarSym =
  1929             (MethodSymbol)lookupSynthetic(classDollar,
  1930                                           outerCacheClass.members());
  1931         if (classDollarSym == null) {
  1932             classDollarSym = new MethodSymbol(
  1933                 STATIC | SYNTHETIC,
  1934                 classDollar,
  1935                 new MethodType(
  1936                     List.of(syms.stringType),
  1937                     types.erasure(syms.classType),
  1938                     List.<Type>nil(),
  1939                     syms.methodClass),
  1940                 outerCacheClass);
  1941             enterSynthetic(pos, classDollarSym, outerCacheClass.members());
  1943             JCMethodDecl md = make.MethodDef(classDollarSym, null);
  1944             try {
  1945                 md.body = classDollarSymBody(pos, md);
  1946             } catch (CompletionFailure ex) {
  1947                 md.body = make.Block(0, List.<JCStatement>nil());
  1948                 chk.completionError(pos, ex);
  1950             JCClassDecl outerCacheClassDef = classDef(outerCacheClass);
  1951             outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(md);
  1953         return classDollarSym;
  1956     /** Generate code for class$(String name). */
  1957     JCBlock classDollarSymBody(DiagnosticPosition pos, JCMethodDecl md) {
  1958         MethodSymbol classDollarSym = md.sym;
  1959         ClassSymbol outerCacheClass = (ClassSymbol)classDollarSym.owner;
  1961         JCBlock returnResult;
  1963         // in 1.4.2 and above, we use
  1964         // Class.forName(String name, boolean init, ClassLoader loader);
  1965         // which requires we cache the current loader in cl$
  1966         if (target.classLiteralsNoInit()) {
  1967             // clsym = "private static ClassLoader cl$"
  1968             VarSymbol clsym = new VarSymbol(STATIC|SYNTHETIC,
  1969                                             names.fromString("cl" + target.syntheticNameChar()),
  1970                                             syms.classLoaderType,
  1971                                             outerCacheClass);
  1972             enterSynthetic(pos, clsym, outerCacheClass.members());
  1974             // emit "private static ClassLoader cl$;"
  1975             JCVariableDecl cldef = make.VarDef(clsym, null);
  1976             JCClassDecl outerCacheClassDef = classDef(outerCacheClass);
  1977             outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cldef);
  1979             // newcache := "new cache$1[0]"
  1980             JCNewArray newcache = make.
  1981                 NewArray(make.Type(outerCacheClass.type),
  1982                          List.<JCExpression>of(make.Literal(INT, 0).setType(syms.intType)),
  1983                          null);
  1984             newcache.type = new ArrayType(types.erasure(outerCacheClass.type),
  1985                                           syms.arrayClass);
  1987             // forNameSym := java.lang.Class.forName(
  1988             //     String s,boolean init,ClassLoader loader)
  1989             Symbol forNameSym = lookupMethod(make_pos, names.forName,
  1990                                              types.erasure(syms.classType),
  1991                                              List.of(syms.stringType,
  1992                                                      syms.booleanType,
  1993                                                      syms.classLoaderType));
  1994             // clvalue := "(cl$ == null) ?
  1995             // $newcache.getClass().getComponentType().getClassLoader() : cl$"
  1996             JCExpression clvalue =
  1997                 make.Conditional(
  1998                     makeBinary(EQ, make.Ident(clsym), makeNull()),
  1999                     make.Assign(
  2000                         make.Ident(clsym),
  2001                         makeCall(
  2002                             makeCall(makeCall(newcache,
  2003                                               names.getClass,
  2004                                               List.<JCExpression>nil()),
  2005                                      names.getComponentType,
  2006                                      List.<JCExpression>nil()),
  2007                             names.getClassLoader,
  2008                             List.<JCExpression>nil())).setType(syms.classLoaderType),
  2009                     make.Ident(clsym)).setType(syms.classLoaderType);
  2011             // returnResult := "{ return Class.forName(param1, false, cl$); }"
  2012             List<JCExpression> args = List.of(make.Ident(md.params.head.sym),
  2013                                               makeLit(syms.booleanType, 0),
  2014                                               clvalue);
  2015             returnResult = make.
  2016                 Block(0, List.<JCStatement>of(make.
  2017                               Call(make. // return
  2018                                    App(make.
  2019                                        Ident(forNameSym), args))));
  2020         } else {
  2021             // forNameSym := java.lang.Class.forName(String s)
  2022             Symbol forNameSym = lookupMethod(make_pos,
  2023                                              names.forName,
  2024                                              types.erasure(syms.classType),
  2025                                              List.of(syms.stringType));
  2026             // returnResult := "{ return Class.forName(param1); }"
  2027             returnResult = make.
  2028                 Block(0, List.of(make.
  2029                           Call(make. // return
  2030                               App(make.
  2031                                   QualIdent(forNameSym),
  2032                                   List.<JCExpression>of(make.
  2033                                                         Ident(md.params.
  2034                                                               head.sym))))));
  2037         // catchParam := ClassNotFoundException e1
  2038         VarSymbol catchParam =
  2039             new VarSymbol(SYNTHETIC, make.paramName(1),
  2040                           syms.classNotFoundExceptionType,
  2041                           classDollarSym);
  2043         JCStatement rethrow;
  2044         if (target.hasInitCause()) {
  2045             // rethrow = "throw new NoClassDefFoundError().initCause(e);
  2046             JCExpression throwExpr =
  2047                 makeCall(makeNewClass(syms.noClassDefFoundErrorType,
  2048                                       List.<JCExpression>nil()),
  2049                          names.initCause,
  2050                          List.<JCExpression>of(make.Ident(catchParam)));
  2051             rethrow = make.Throw(throwExpr);
  2052         } else {
  2053             // getMessageSym := ClassNotFoundException.getMessage()
  2054             Symbol getMessageSym = lookupMethod(make_pos,
  2055                                                 names.getMessage,
  2056                                                 syms.classNotFoundExceptionType,
  2057                                                 List.<Type>nil());
  2058             // rethrow = "throw new NoClassDefFoundError(e.getMessage());"
  2059             rethrow = make.
  2060                 Throw(makeNewClass(syms.noClassDefFoundErrorType,
  2061                           List.<JCExpression>of(make.App(make.Select(make.Ident(catchParam),
  2062                                                                      getMessageSym),
  2063                                                          List.<JCExpression>nil()))));
  2066         // rethrowStmt := "( $rethrow )"
  2067         JCBlock rethrowStmt = make.Block(0, List.of(rethrow));
  2069         // catchBlock := "catch ($catchParam) $rethrowStmt"
  2070         JCCatch catchBlock = make.Catch(make.VarDef(catchParam, null),
  2071                                       rethrowStmt);
  2073         // tryCatch := "try $returnResult $catchBlock"
  2074         JCStatement tryCatch = make.Try(returnResult,
  2075                                         List.of(catchBlock), null);
  2077         return make.Block(0, List.of(tryCatch));
  2079     // where
  2080         /** Create an attributed tree of the form left.name(). */
  2081         private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) {
  2082             Assert.checkNonNull(left.type);
  2083             Symbol funcsym = lookupMethod(make_pos, name, left.type,
  2084                                           TreeInfo.types(args));
  2085             return make.App(make.Select(left, funcsym), args);
  2088     /** The Name Of The variable to cache T.class values.
  2089      *  @param sig      The signature of type T.
  2090      */
  2091     private Name cacheName(String sig) {
  2092         StringBuilder buf = new StringBuilder();
  2093         if (sig.startsWith("[")) {
  2094             buf = buf.append("array");
  2095             while (sig.startsWith("[")) {
  2096                 buf = buf.append(target.syntheticNameChar());
  2097                 sig = sig.substring(1);
  2099             if (sig.startsWith("L")) {
  2100                 sig = sig.substring(0, sig.length() - 1);
  2102         } else {
  2103             buf = buf.append("class" + target.syntheticNameChar());
  2105         buf = buf.append(sig.replace('.', target.syntheticNameChar()));
  2106         return names.fromString(buf.toString());
  2109     /** The variable symbol that caches T.class values.
  2110      *  If none exists yet, create a definition.
  2111      *  @param sig      The signature of type T.
  2112      *  @param pos      The position to report diagnostics, if any.
  2113      */
  2114     private VarSymbol cacheSym(DiagnosticPosition pos, String sig) {
  2115         ClassSymbol outerCacheClass = outerCacheClass();
  2116         Name cname = cacheName(sig);
  2117         VarSymbol cacheSym =
  2118             (VarSymbol)lookupSynthetic(cname, outerCacheClass.members());
  2119         if (cacheSym == null) {
  2120             cacheSym = new VarSymbol(
  2121                 STATIC | SYNTHETIC, cname, types.erasure(syms.classType), outerCacheClass);
  2122             enterSynthetic(pos, cacheSym, outerCacheClass.members());
  2124             JCVariableDecl cacheDef = make.VarDef(cacheSym, null);
  2125             JCClassDecl outerCacheClassDef = classDef(outerCacheClass);
  2126             outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cacheDef);
  2128         return cacheSym;
  2131     /** The tree simulating a T.class expression.
  2132      *  @param clazz      The tree identifying type T.
  2133      */
  2134     private JCExpression classOf(JCTree clazz) {
  2135         return classOfType(clazz.type, clazz.pos());
  2138     private JCExpression classOfType(Type type, DiagnosticPosition pos) {
  2139         switch (type.getTag()) {
  2140         case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT:
  2141         case DOUBLE: case BOOLEAN: case VOID:
  2142             // replace with <BoxedClass>.TYPE
  2143             ClassSymbol c = types.boxedClass(type);
  2144             Symbol typeSym =
  2145                 rs.accessBase(
  2146                     rs.findIdentInType(attrEnv, c.type, names.TYPE, VAR),
  2147                     pos, c.type, names.TYPE, true);
  2148             if (typeSym.kind == VAR)
  2149                 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated
  2150             return make.QualIdent(typeSym);
  2151         case CLASS: case ARRAY:
  2152             if (target.hasClassLiterals()) {
  2153                 VarSymbol sym = new VarSymbol(
  2154                         STATIC | PUBLIC | FINAL, names._class,
  2155                         syms.classType, type.tsym);
  2156                 return make_at(pos).Select(make.Type(type), sym);
  2158             // replace with <cache == null ? cache = class$(tsig) : cache>
  2159             // where
  2160             //  - <tsig>  is the type signature of T,
  2161             //  - <cache> is the cache variable for tsig.
  2162             String sig =
  2163                 writer.xClassName(type).toString().replace('/', '.');
  2164             Symbol cs = cacheSym(pos, sig);
  2165             return make_at(pos).Conditional(
  2166                 makeBinary(EQ, make.Ident(cs), makeNull()),
  2167                 make.Assign(
  2168                     make.Ident(cs),
  2169                     make.App(
  2170                         make.Ident(classDollarSym(pos)),
  2171                         List.<JCExpression>of(make.Literal(CLASS, sig)
  2172                                               .setType(syms.stringType))))
  2173                 .setType(types.erasure(syms.classType)),
  2174                 make.Ident(cs)).setType(types.erasure(syms.classType));
  2175         default:
  2176             throw new AssertionError();
  2180 /**************************************************************************
  2181  * Code for enabling/disabling assertions.
  2182  *************************************************************************/
  2184     private ClassSymbol assertionsDisabledClassCache;
  2186     /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces.
  2187      */
  2188     private ClassSymbol assertionsDisabledClass() {
  2189         if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache;
  2191         assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym;
  2193         return assertionsDisabledClassCache;
  2196     // This code is not particularly robust if the user has
  2197     // previously declared a member named '$assertionsDisabled'.
  2198     // The same faulty idiom also appears in the translation of
  2199     // class literals above.  We should report an error if a
  2200     // previous declaration is not synthetic.
  2202     private JCExpression assertFlagTest(DiagnosticPosition pos) {
  2203         // Outermost class may be either true class or an interface.
  2204         ClassSymbol outermostClass = outermostClassDef.sym;
  2206         //only classes can hold a non-public field, look for a usable one:
  2207         ClassSymbol container = !currentClass.isInterface() ? currentClass :
  2208                 assertionsDisabledClass();
  2210         VarSymbol assertDisabledSym =
  2211             (VarSymbol)lookupSynthetic(dollarAssertionsDisabled,
  2212                                        container.members());
  2213         if (assertDisabledSym == null) {
  2214             assertDisabledSym =
  2215                 new VarSymbol(STATIC | FINAL | SYNTHETIC,
  2216                               dollarAssertionsDisabled,
  2217                               syms.booleanType,
  2218                               container);
  2219             enterSynthetic(pos, assertDisabledSym, container.members());
  2220             Symbol desiredAssertionStatusSym = lookupMethod(pos,
  2221                                                             names.desiredAssertionStatus,
  2222                                                             types.erasure(syms.classType),
  2223                                                             List.<Type>nil());
  2224             JCClassDecl containerDef = classDef(container);
  2225             make_at(containerDef.pos());
  2226             JCExpression notStatus = makeUnary(NOT, make.App(make.Select(
  2227                     classOfType(types.erasure(outermostClass.type),
  2228                                 containerDef.pos()),
  2229                     desiredAssertionStatusSym)));
  2230             JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym,
  2231                                                    notStatus);
  2232             containerDef.defs = containerDef.defs.prepend(assertDisabledDef);
  2234             if (currentClass.isInterface()) {
  2235                 //need to load the assertions enabled/disabled state while
  2236                 //initializing the interface:
  2237                 JCClassDecl currentClassDef = classDef(currentClass);
  2238                 make_at(currentClassDef.pos());
  2239                 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null);
  2240                 JCBlock clinit = make.Block(STATIC, List.<JCStatement>of(dummy));
  2241                 currentClassDef.defs = currentClassDef.defs.prepend(clinit);
  2244         make_at(pos);
  2245         return makeUnary(NOT, make.Ident(assertDisabledSym));
  2249 /**************************************************************************
  2250  * Building blocks for let expressions
  2251  *************************************************************************/
  2253     interface TreeBuilder {
  2254         JCTree build(JCTree arg);
  2257     /** Construct an expression using the builder, with the given rval
  2258      *  expression as an argument to the builder.  However, the rval
  2259      *  expression must be computed only once, even if used multiple
  2260      *  times in the result of the builder.  We do that by
  2261      *  constructing a "let" expression that saves the rvalue into a
  2262      *  temporary variable and then uses the temporary variable in
  2263      *  place of the expression built by the builder.  The complete
  2264      *  resulting expression is of the form
  2265      *  <pre>
  2266      *    (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>;
  2267      *     in (<b>BUILDER</b>(<b>TEMP</b>)))
  2268      *  </pre>
  2269      *  where <code><b>TEMP</b></code> is a newly declared variable
  2270      *  in the let expression.
  2271      */
  2272     JCTree abstractRval(JCTree rval, Type type, TreeBuilder builder) {
  2273         rval = TreeInfo.skipParens(rval);
  2274         switch (rval.getTag()) {
  2275         case LITERAL:
  2276             return builder.build(rval);
  2277         case IDENT:
  2278             JCIdent id = (JCIdent) rval;
  2279             if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH)
  2280                 return builder.build(rval);
  2282         VarSymbol var =
  2283             new VarSymbol(FINAL|SYNTHETIC,
  2284                           names.fromString(
  2285                                           target.syntheticNameChar()
  2286                                           + "" + rval.hashCode()),
  2287                                       type,
  2288                                       currentMethodSym);
  2289         rval = convert(rval,type);
  2290         JCVariableDecl def = make.VarDef(var, (JCExpression)rval); // XXX cast
  2291         JCTree built = builder.build(make.Ident(var));
  2292         JCTree res = make.LetExpr(def, built);
  2293         res.type = built.type;
  2294         return res;
  2297     // same as above, with the type of the temporary variable computed
  2298     JCTree abstractRval(JCTree rval, TreeBuilder builder) {
  2299         return abstractRval(rval, rval.type, builder);
  2302     // same as above, but for an expression that may be used as either
  2303     // an rvalue or an lvalue.  This requires special handling for
  2304     // Select expressions, where we place the left-hand-side of the
  2305     // select in a temporary, and for Indexed expressions, where we
  2306     // place both the indexed expression and the index value in temps.
  2307     JCTree abstractLval(JCTree lval, final TreeBuilder builder) {
  2308         lval = TreeInfo.skipParens(lval);
  2309         switch (lval.getTag()) {
  2310         case IDENT:
  2311             return builder.build(lval);
  2312         case SELECT: {
  2313             final JCFieldAccess s = (JCFieldAccess)lval;
  2314             JCTree selected = TreeInfo.skipParens(s.selected);
  2315             Symbol lid = TreeInfo.symbol(s.selected);
  2316             if (lid != null && lid.kind == TYP) return builder.build(lval);
  2317             return abstractRval(s.selected, new TreeBuilder() {
  2318                     public JCTree build(final JCTree selected) {
  2319                         return builder.build(make.Select((JCExpression)selected, s.sym));
  2321                 });
  2323         case INDEXED: {
  2324             final JCArrayAccess i = (JCArrayAccess)lval;
  2325             return abstractRval(i.indexed, new TreeBuilder() {
  2326                     public JCTree build(final JCTree indexed) {
  2327                         return abstractRval(i.index, syms.intType, new TreeBuilder() {
  2328                                 public JCTree build(final JCTree index) {
  2329                                     JCTree newLval = make.Indexed((JCExpression)indexed,
  2330                                                                 (JCExpression)index);
  2331                                     newLval.setType(i.type);
  2332                                     return builder.build(newLval);
  2334                             });
  2336                 });
  2338         case TYPECAST: {
  2339             return abstractLval(((JCTypeCast)lval).expr, builder);
  2342         throw new AssertionError(lval);
  2345     // evaluate and discard the first expression, then evaluate the second.
  2346     JCTree makeComma(final JCTree expr1, final JCTree expr2) {
  2347         return abstractRval(expr1, new TreeBuilder() {
  2348                 public JCTree build(final JCTree discarded) {
  2349                     return expr2;
  2351             });
  2354 /**************************************************************************
  2355  * Translation methods
  2356  *************************************************************************/
  2358     /** Visitor argument: enclosing operator node.
  2359      */
  2360     private JCExpression enclOp;
  2362     /** Visitor method: Translate a single node.
  2363      *  Attach the source position from the old tree to its replacement tree.
  2364      */
  2365     @Override
  2366     public <T extends JCTree> T translate(T tree) {
  2367         if (tree == null) {
  2368             return null;
  2369         } else {
  2370             make_at(tree.pos());
  2371             T result = super.translate(tree);
  2372             if (endPosTable != null && result != tree) {
  2373                 endPosTable.replaceTree(tree, result);
  2375             return result;
  2379     /** Visitor method: Translate a single node, boxing or unboxing if needed.
  2380      */
  2381     public <T extends JCTree> T translate(T tree, Type type) {
  2382         return (tree == null) ? null : boxIfNeeded(translate(tree), type);
  2385     /** Visitor method: Translate tree.
  2386      */
  2387     public <T extends JCTree> T translate(T tree, JCExpression enclOp) {
  2388         JCExpression prevEnclOp = this.enclOp;
  2389         this.enclOp = enclOp;
  2390         T res = translate(tree);
  2391         this.enclOp = prevEnclOp;
  2392         return res;
  2395     /** Visitor method: Translate list of trees.
  2396      */
  2397     public <T extends JCTree> List<T> translate(List<T> trees, JCExpression enclOp) {
  2398         JCExpression prevEnclOp = this.enclOp;
  2399         this.enclOp = enclOp;
  2400         List<T> res = translate(trees);
  2401         this.enclOp = prevEnclOp;
  2402         return res;
  2405     /** Visitor method: Translate list of trees.
  2406      */
  2407     public <T extends JCTree> List<T> translate(List<T> trees, Type type) {
  2408         if (trees == null) return null;
  2409         for (List<T> l = trees; l.nonEmpty(); l = l.tail)
  2410             l.head = translate(l.head, type);
  2411         return trees;
  2414     public void visitTopLevel(JCCompilationUnit tree) {
  2415         if (needPackageInfoClass(tree)) {
  2416             Name name = names.package_info;
  2417             long flags = Flags.ABSTRACT | Flags.INTERFACE;
  2418             if (target.isPackageInfoSynthetic())
  2419                 // package-info is marked SYNTHETIC in JDK 1.6 and later releases
  2420                 flags = flags | Flags.SYNTHETIC;
  2421             JCClassDecl packageAnnotationsClass
  2422                 = make.ClassDef(make.Modifiers(flags,
  2423                                                tree.packageAnnotations),
  2424                                 name, List.<JCTypeParameter>nil(),
  2425                                 null, List.<JCExpression>nil(), List.<JCTree>nil());
  2426             ClassSymbol c = tree.packge.package_info;
  2427             c.flags_field |= flags;
  2428             c.setAttributes(tree.packge);
  2429             ClassType ctype = (ClassType) c.type;
  2430             ctype.supertype_field = syms.objectType;
  2431             ctype.interfaces_field = List.nil();
  2432             packageAnnotationsClass.sym = c;
  2434             translated.append(packageAnnotationsClass);
  2437     // where
  2438     private boolean needPackageInfoClass(JCCompilationUnit tree) {
  2439         switch (pkginfoOpt) {
  2440             case ALWAYS:
  2441                 return true;
  2442             case LEGACY:
  2443                 return tree.packageAnnotations.nonEmpty();
  2444             case NONEMPTY:
  2445                 for (Attribute.Compound a :
  2446                          tree.packge.getDeclarationAttributes()) {
  2447                     Attribute.RetentionPolicy p = types.getRetention(a);
  2448                     if (p != Attribute.RetentionPolicy.SOURCE)
  2449                         return true;
  2451                 return false;
  2453         throw new AssertionError();
  2456     public void visitClassDef(JCClassDecl tree) {
  2457         Env<AttrContext> prevEnv = attrEnv;
  2458         ClassSymbol currentClassPrev = currentClass;
  2459         MethodSymbol currentMethodSymPrev = currentMethodSym;
  2461         currentClass = tree.sym;
  2462         currentMethodSym = null;
  2463         attrEnv = typeEnvs.remove(currentClass);
  2464         if (attrEnv == null)
  2465             attrEnv = prevEnv;
  2467         classdefs.put(currentClass, tree);
  2469         proxies = proxies.dup(currentClass);
  2470         List<VarSymbol> prevOuterThisStack = outerThisStack;
  2472         // If this is an enum definition
  2473         if ((tree.mods.flags & ENUM) != 0 &&
  2474             (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0)
  2475             visitEnumDef(tree);
  2477         // If this is a nested class, define a this$n field for
  2478         // it and add to proxies.
  2479         JCVariableDecl otdef = null;
  2480         if (currentClass.hasOuterInstance())
  2481             otdef = outerThisDef(tree.pos, currentClass);
  2483         // If this is a local class, define proxies for all its free variables.
  2484         List<JCVariableDecl> fvdefs = freevarDefs(
  2485             tree.pos, freevars(currentClass), currentClass);
  2487         // Recursively translate superclass, interfaces.
  2488         tree.extending = translate(tree.extending);
  2489         tree.implementing = translate(tree.implementing);
  2491         if (currentClass.isLocal()) {
  2492             ClassSymbol encl = currentClass.owner.enclClass();
  2493             if (encl.trans_local == null) {
  2494                 encl.trans_local = List.nil();
  2496             encl.trans_local = encl.trans_local.prepend(currentClass);
  2499         // Recursively translate members, taking into account that new members
  2500         // might be created during the translation and prepended to the member
  2501         // list `tree.defs'.
  2502         List<JCTree> seen = List.nil();
  2503         while (tree.defs != seen) {
  2504             List<JCTree> unseen = tree.defs;
  2505             for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) {
  2506                 JCTree outermostMemberDefPrev = outermostMemberDef;
  2507                 if (outermostMemberDefPrev == null) outermostMemberDef = l.head;
  2508                 l.head = translate(l.head);
  2509                 outermostMemberDef = outermostMemberDefPrev;
  2511             seen = unseen;
  2514         // Convert a protected modifier to public, mask static modifier.
  2515         if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC;
  2516         tree.mods.flags &= ClassFlags;
  2518         // Convert name to flat representation, replacing '.' by '$'.
  2519         tree.name = Convert.shortName(currentClass.flatName());
  2521         // Add this$n and free variables proxy definitions to class.
  2523         for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) {
  2524             tree.defs = tree.defs.prepend(l.head);
  2525             enterSynthetic(tree.pos(), l.head.sym, currentClass.members());
  2527         if (currentClass.hasOuterInstance()) {
  2528             tree.defs = tree.defs.prepend(otdef);
  2529             enterSynthetic(tree.pos(), otdef.sym, currentClass.members());
  2532         proxies = proxies.leave();
  2533         outerThisStack = prevOuterThisStack;
  2535         // Append translated tree to `translated' queue.
  2536         translated.append(tree);
  2538         attrEnv = prevEnv;
  2539         currentClass = currentClassPrev;
  2540         currentMethodSym = currentMethodSymPrev;
  2542         // Return empty block {} as a placeholder for an inner class.
  2543         result = make_at(tree.pos()).Block(SYNTHETIC, List.<JCStatement>nil());
  2546     /** Translate an enum class. */
  2547     private void visitEnumDef(JCClassDecl tree) {
  2548         make_at(tree.pos());
  2550         // add the supertype, if needed
  2551         if (tree.extending == null)
  2552             tree.extending = make.Type(types.supertype(tree.type));
  2554         // classOfType adds a cache field to tree.defs unless
  2555         // target.hasClassLiterals().
  2556         JCExpression e_class = classOfType(tree.sym.type, tree.pos()).
  2557             setType(types.erasure(syms.classType));
  2559         // process each enumeration constant, adding implicit constructor parameters
  2560         int nextOrdinal = 0;
  2561         ListBuffer<JCExpression> values = new ListBuffer<JCExpression>();
  2562         ListBuffer<JCTree> enumDefs = new ListBuffer<JCTree>();
  2563         ListBuffer<JCTree> otherDefs = new ListBuffer<JCTree>();
  2564         for (List<JCTree> defs = tree.defs;
  2565              defs.nonEmpty();
  2566              defs=defs.tail) {
  2567             if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
  2568                 JCVariableDecl var = (JCVariableDecl)defs.head;
  2569                 visitEnumConstantDef(var, nextOrdinal++);
  2570                 values.append(make.QualIdent(var.sym));
  2571                 enumDefs.append(var);
  2572             } else {
  2573                 otherDefs.append(defs.head);
  2577         // private static final T[] #VALUES = { a, b, c };
  2578         Name valuesName = names.fromString(target.syntheticNameChar() + "VALUES");
  2579         while (tree.sym.members().lookup(valuesName).scope != null) // avoid name clash
  2580             valuesName = names.fromString(valuesName + "" + target.syntheticNameChar());
  2581         Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass);
  2582         VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC,
  2583                                             valuesName,
  2584                                             arrayType,
  2585                                             tree.type.tsym);
  2586         JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)),
  2587                                           List.<JCExpression>nil(),
  2588                                           values.toList());
  2589         newArray.type = arrayType;
  2590         enumDefs.append(make.VarDef(valuesVar, newArray));
  2591         tree.sym.members().enter(valuesVar);
  2593         Symbol valuesSym = lookupMethod(tree.pos(), names.values,
  2594                                         tree.type, List.<Type>nil());
  2595         List<JCStatement> valuesBody;
  2596         if (useClone()) {
  2597             // return (T[]) $VALUES.clone();
  2598             JCTypeCast valuesResult =
  2599                 make.TypeCast(valuesSym.type.getReturnType(),
  2600                               make.App(make.Select(make.Ident(valuesVar),
  2601                                                    syms.arrayCloneMethod)));
  2602             valuesBody = List.<JCStatement>of(make.Return(valuesResult));
  2603         } else {
  2604             // template: T[] $result = new T[$values.length];
  2605             Name resultName = names.fromString(target.syntheticNameChar() + "result");
  2606             while (tree.sym.members().lookup(resultName).scope != null) // avoid name clash
  2607                 resultName = names.fromString(resultName + "" + target.syntheticNameChar());
  2608             VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC,
  2609                                                 resultName,
  2610                                                 arrayType,
  2611                                                 valuesSym);
  2612             JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)),
  2613                                   List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)),
  2614                                   null);
  2615             resultArray.type = arrayType;
  2616             JCVariableDecl decl = make.VarDef(resultVar, resultArray);
  2618             // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length);
  2619             if (systemArraycopyMethod == null) {
  2620                 systemArraycopyMethod =
  2621                     new MethodSymbol(PUBLIC | STATIC,
  2622                                      names.fromString("arraycopy"),
  2623                                      new MethodType(List.<Type>of(syms.objectType,
  2624                                                             syms.intType,
  2625                                                             syms.objectType,
  2626                                                             syms.intType,
  2627                                                             syms.intType),
  2628                                                     syms.voidType,
  2629                                                     List.<Type>nil(),
  2630                                                     syms.methodClass),
  2631                                      syms.systemType.tsym);
  2633             JCStatement copy =
  2634                 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym),
  2635                                                systemArraycopyMethod),
  2636                           List.of(make.Ident(valuesVar), make.Literal(0),
  2637                                   make.Ident(resultVar), make.Literal(0),
  2638                                   make.Select(make.Ident(valuesVar), syms.lengthVar))));
  2640             // template: return $result;
  2641             JCStatement ret = make.Return(make.Ident(resultVar));
  2642             valuesBody = List.<JCStatement>of(decl, copy, ret);
  2645         JCMethodDecl valuesDef =
  2646              make.MethodDef((MethodSymbol)valuesSym, make.Block(0, valuesBody));
  2648         enumDefs.append(valuesDef);
  2650         if (debugLower)
  2651             System.err.println(tree.sym + ".valuesDef = " + valuesDef);
  2653         /** The template for the following code is:
  2655          *     public static E valueOf(String name) {
  2656          *         return (E)Enum.valueOf(E.class, name);
  2657          *     }
  2659          *  where E is tree.sym
  2660          */
  2661         MethodSymbol valueOfSym = lookupMethod(tree.pos(),
  2662                          names.valueOf,
  2663                          tree.sym.type,
  2664                          List.of(syms.stringType));
  2665         Assert.check((valueOfSym.flags() & STATIC) != 0);
  2666         VarSymbol nameArgSym = valueOfSym.params.head;
  2667         JCIdent nameVal = make.Ident(nameArgSym);
  2668         JCStatement enum_ValueOf =
  2669             make.Return(make.TypeCast(tree.sym.type,
  2670                                       makeCall(make.Ident(syms.enumSym),
  2671                                                names.valueOf,
  2672                                                List.of(e_class, nameVal))));
  2673         JCMethodDecl valueOf = make.MethodDef(valueOfSym,
  2674                                            make.Block(0, List.of(enum_ValueOf)));
  2675         nameVal.sym = valueOf.params.head.sym;
  2676         if (debugLower)
  2677             System.err.println(tree.sym + ".valueOf = " + valueOf);
  2678         enumDefs.append(valueOf);
  2680         enumDefs.appendList(otherDefs.toList());
  2681         tree.defs = enumDefs.toList();
  2683         // where
  2684         private MethodSymbol systemArraycopyMethod;
  2685         private boolean useClone() {
  2686             try {
  2687                 Scope.Entry e = syms.objectType.tsym.members().lookup(names.clone);
  2688                 return (e.sym != null);
  2690             catch (CompletionFailure e) {
  2691                 return false;
  2695     /** Translate an enumeration constant and its initializer. */
  2696     private void visitEnumConstantDef(JCVariableDecl var, int ordinal) {
  2697         JCNewClass varDef = (JCNewClass)var.init;
  2698         varDef.args = varDef.args.
  2699             prepend(makeLit(syms.intType, ordinal)).
  2700             prepend(makeLit(syms.stringType, var.name.toString()));
  2703     public void visitMethodDef(JCMethodDecl tree) {
  2704         if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) {
  2705             // Add "String $enum$name, int $enum$ordinal" to the beginning of the
  2706             // argument list for each constructor of an enum.
  2707             JCVariableDecl nameParam = make_at(tree.pos()).
  2708                 Param(names.fromString(target.syntheticNameChar() +
  2709                                        "enum" + target.syntheticNameChar() + "name"),
  2710                       syms.stringType, tree.sym);
  2711             nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC;
  2712             JCVariableDecl ordParam = make.
  2713                 Param(names.fromString(target.syntheticNameChar() +
  2714                                        "enum" + target.syntheticNameChar() +
  2715                                        "ordinal"),
  2716                       syms.intType, tree.sym);
  2717             ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC;
  2719             tree.params = tree.params.prepend(ordParam).prepend(nameParam);
  2721             MethodSymbol m = tree.sym;
  2722             m.extraParams = m.extraParams.prepend(ordParam.sym);
  2723             m.extraParams = m.extraParams.prepend(nameParam.sym);
  2724             Type olderasure = m.erasure(types);
  2725             m.erasure_field = new MethodType(
  2726                 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType),
  2727                 olderasure.getReturnType(),
  2728                 olderasure.getThrownTypes(),
  2729                 syms.methodClass);
  2732         JCMethodDecl prevMethodDef = currentMethodDef;
  2733         MethodSymbol prevMethodSym = currentMethodSym;
  2734         try {
  2735             currentMethodDef = tree;
  2736             currentMethodSym = tree.sym;
  2737             visitMethodDefInternal(tree);
  2738         } finally {
  2739             currentMethodDef = prevMethodDef;
  2740             currentMethodSym = prevMethodSym;
  2743     //where
  2744     private void visitMethodDefInternal(JCMethodDecl tree) {
  2745         if (tree.name == names.init &&
  2746             (currentClass.isInner() || currentClass.isLocal())) {
  2747             // We are seeing a constructor of an inner class.
  2748             MethodSymbol m = tree.sym;
  2750             // Push a new proxy scope for constructor parameters.
  2751             // and create definitions for any this$n and proxy parameters.
  2752             proxies = proxies.dup(m);
  2753             List<VarSymbol> prevOuterThisStack = outerThisStack;
  2754             List<VarSymbol> fvs = freevars(currentClass);
  2755             JCVariableDecl otdef = null;
  2756             if (currentClass.hasOuterInstance())
  2757                 otdef = outerThisDef(tree.pos, m);
  2758             List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER);
  2760             // Recursively translate result type, parameters and thrown list.
  2761             tree.restype = translate(tree.restype);
  2762             tree.params = translateVarDefs(tree.params);
  2763             tree.thrown = translate(tree.thrown);
  2765             // when compiling stubs, don't process body
  2766             if (tree.body == null) {
  2767                 result = tree;
  2768                 return;
  2771             // Add this$n (if needed) in front of and free variables behind
  2772             // constructor parameter list.
  2773             tree.params = tree.params.appendList(fvdefs);
  2774             if (currentClass.hasOuterInstance())
  2775                 tree.params = tree.params.prepend(otdef);
  2777             // If this is an initial constructor, i.e., it does not start with
  2778             // this(...), insert initializers for this$n and proxies
  2779             // before (pre-1.4, after) the call to superclass constructor.
  2780             JCStatement selfCall = translate(tree.body.stats.head);
  2782             List<JCStatement> added = List.nil();
  2783             if (fvs.nonEmpty()) {
  2784                 List<Type> addedargtypes = List.nil();
  2785                 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
  2786                     if (TreeInfo.isInitialConstructor(tree)) {
  2787                         final Name pName = proxyName(l.head.name);
  2788                         m.capturedLocals =
  2789                             m.capturedLocals.append((VarSymbol)
  2790                                                     (proxies.lookup(pName).sym));
  2791                         added = added.prepend(
  2792                           initField(tree.body.pos, pName));
  2794                     addedargtypes = addedargtypes.prepend(l.head.erasure(types));
  2796                 Type olderasure = m.erasure(types);
  2797                 m.erasure_field = new MethodType(
  2798                     olderasure.getParameterTypes().appendList(addedargtypes),
  2799                     olderasure.getReturnType(),
  2800                     olderasure.getThrownTypes(),
  2801                     syms.methodClass);
  2803             if (currentClass.hasOuterInstance() &&
  2804                 TreeInfo.isInitialConstructor(tree))
  2806                 added = added.prepend(initOuterThis(tree.body.pos));
  2809             // pop local variables from proxy stack
  2810             proxies = proxies.leave();
  2812             // recursively translate following local statements and
  2813             // combine with this- or super-call
  2814             List<JCStatement> stats = translate(tree.body.stats.tail);
  2815             if (target.initializeFieldsBeforeSuper())
  2816                 tree.body.stats = stats.prepend(selfCall).prependList(added);
  2817             else
  2818                 tree.body.stats = stats.prependList(added).prepend(selfCall);
  2820             outerThisStack = prevOuterThisStack;
  2821         } else {
  2822             Map<Symbol, Symbol> prevLambdaTranslationMap =
  2823                     lambdaTranslationMap;
  2824             try {
  2825                 lambdaTranslationMap = (tree.sym.flags() & SYNTHETIC) != 0 &&
  2826                         tree.sym.name.startsWith(names.lambda) ?
  2827                         makeTranslationMap(tree) : null;
  2828                 super.visitMethodDef(tree);
  2829             } finally {
  2830                 lambdaTranslationMap = prevLambdaTranslationMap;
  2833         result = tree;
  2835     //where
  2836         private Map<Symbol, Symbol> makeTranslationMap(JCMethodDecl tree) {
  2837             Map<Symbol, Symbol> translationMap = new HashMap<Symbol,Symbol>();
  2838             for (JCVariableDecl vd : tree.params) {
  2839                 Symbol p = vd.sym;
  2840                 if (p != p.baseSymbol()) {
  2841                     translationMap.put(p.baseSymbol(), p);
  2844             return translationMap;
  2847     public void visitAnnotatedType(JCAnnotatedType tree) {
  2848         // No need to retain type annotations in the tree
  2849         // tree.annotations = translate(tree.annotations);
  2850         tree.annotations = List.nil();
  2851         tree.underlyingType = translate(tree.underlyingType);
  2852         // but maintain type annotations in the type.
  2853         if (tree.type.isAnnotated()) {
  2854             tree.type = tree.underlyingType.type.unannotatedType().annotatedType(tree.type.getAnnotationMirrors());
  2855         } else if (tree.underlyingType.type.isAnnotated()) {
  2856             tree.type = tree.underlyingType.type;
  2858         result = tree;
  2861     public void visitTypeCast(JCTypeCast tree) {
  2862         tree.clazz = translate(tree.clazz);
  2863         if (tree.type.isPrimitive() != tree.expr.type.isPrimitive())
  2864             tree.expr = translate(tree.expr, tree.type);
  2865         else
  2866             tree.expr = translate(tree.expr);
  2867         result = tree;
  2870     public void visitNewClass(JCNewClass tree) {
  2871         ClassSymbol c = (ClassSymbol)tree.constructor.owner;
  2873         // Box arguments, if necessary
  2874         boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0;
  2875         List<Type> argTypes = tree.constructor.type.getParameterTypes();
  2876         if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType);
  2877         tree.args = boxArgs(argTypes, tree.args, tree.varargsElement);
  2878         tree.varargsElement = null;
  2880         // If created class is local, add free variables after
  2881         // explicit constructor arguments.
  2882         if (c.isLocal()) {
  2883             tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
  2886         // If an access constructor is used, append null as a last argument.
  2887         Symbol constructor = accessConstructor(tree.pos(), tree.constructor);
  2888         if (constructor != tree.constructor) {
  2889             tree.args = tree.args.append(makeNull());
  2890             tree.constructor = constructor;
  2893         // If created class has an outer instance, and new is qualified, pass
  2894         // qualifier as first argument. If new is not qualified, pass the
  2895         // correct outer instance as first argument.
  2896         if (c.hasOuterInstance()) {
  2897             JCExpression thisArg;
  2898             if (tree.encl != null) {
  2899                 thisArg = attr.makeNullCheck(translate(tree.encl));
  2900                 thisArg.type = tree.encl.type;
  2901             } else if (c.isLocal()) {
  2902                 // local class
  2903                 thisArg = makeThis(tree.pos(), c.type.getEnclosingType().tsym);
  2904             } else {
  2905                 // nested class
  2906                 thisArg = makeOwnerThis(tree.pos(), c, false);
  2908             tree.args = tree.args.prepend(thisArg);
  2910         tree.encl = null;
  2912         // If we have an anonymous class, create its flat version, rather
  2913         // than the class or interface following new.
  2914         if (tree.def != null) {
  2915             translate(tree.def);
  2916             tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym));
  2917             tree.def = null;
  2918         } else {
  2919             tree.clazz = access(c, tree.clazz, enclOp, false);
  2921         result = tree;
  2924     // Simplify conditionals with known constant controlling expressions.
  2925     // This allows us to avoid generating supporting declarations for
  2926     // the dead code, which will not be eliminated during code generation.
  2927     // Note that Flow.isFalse and Flow.isTrue only return true
  2928     // for constant expressions in the sense of JLS 15.27, which
  2929     // are guaranteed to have no side-effects.  More aggressive
  2930     // constant propagation would require that we take care to
  2931     // preserve possible side-effects in the condition expression.
  2933     /** Visitor method for conditional expressions.
  2934      */
  2935     @Override
  2936     public void visitConditional(JCConditional tree) {
  2937         JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
  2938         if (cond.type.isTrue()) {
  2939             result = convert(translate(tree.truepart, tree.type), tree.type);
  2940             addPrunedInfo(cond);
  2941         } else if (cond.type.isFalse()) {
  2942             result = convert(translate(tree.falsepart, tree.type), tree.type);
  2943             addPrunedInfo(cond);
  2944         } else {
  2945             // Condition is not a compile-time constant.
  2946             tree.truepart = translate(tree.truepart, tree.type);
  2947             tree.falsepart = translate(tree.falsepart, tree.type);
  2948             result = tree;
  2951 //where
  2952     private JCTree convert(JCTree tree, Type pt) {
  2953         if (tree.type == pt || tree.type.hasTag(BOT))
  2954             return tree;
  2955         JCTree result = make_at(tree.pos()).TypeCast(make.Type(pt), (JCExpression)tree);
  2956         result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt)
  2957                                                        : pt;
  2958         return result;
  2961     /** Visitor method for if statements.
  2962      */
  2963     public void visitIf(JCIf tree) {
  2964         JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
  2965         if (cond.type.isTrue()) {
  2966             result = translate(tree.thenpart);
  2967             addPrunedInfo(cond);
  2968         } else if (cond.type.isFalse()) {
  2969             if (tree.elsepart != null) {
  2970                 result = translate(tree.elsepart);
  2971             } else {
  2972                 result = make.Skip();
  2974             addPrunedInfo(cond);
  2975         } else {
  2976             // Condition is not a compile-time constant.
  2977             tree.thenpart = translate(tree.thenpart);
  2978             tree.elsepart = translate(tree.elsepart);
  2979             result = tree;
  2983     /** Visitor method for assert statements. Translate them away.
  2984      */
  2985     public void visitAssert(JCAssert tree) {
  2986         DiagnosticPosition detailPos = (tree.detail == null) ? tree.pos() : tree.detail.pos();
  2987         tree.cond = translate(tree.cond, syms.booleanType);
  2988         if (!tree.cond.type.isTrue()) {
  2989             JCExpression cond = assertFlagTest(tree.pos());
  2990             List<JCExpression> exnArgs = (tree.detail == null) ?
  2991                 List.<JCExpression>nil() : List.of(translate(tree.detail));
  2992             if (!tree.cond.type.isFalse()) {
  2993                 cond = makeBinary
  2994                     (AND,
  2995                      cond,
  2996                      makeUnary(NOT, tree.cond));
  2998             result =
  2999                 make.If(cond,
  3000                         make_at(tree).
  3001                            Throw(makeNewClass(syms.assertionErrorType, exnArgs)),
  3002                         null);
  3003         } else {
  3004             result = make.Skip();
  3008     public void visitApply(JCMethodInvocation tree) {
  3009         Symbol meth = TreeInfo.symbol(tree.meth);
  3010         List<Type> argtypes = meth.type.getParameterTypes();
  3011         if (allowEnums &&
  3012             meth.name==names.init &&
  3013             meth.owner == syms.enumSym)
  3014             argtypes = argtypes.tail.tail;
  3015         tree.args = boxArgs(argtypes, tree.args, tree.varargsElement);
  3016         tree.varargsElement = null;
  3017         Name methName = TreeInfo.name(tree.meth);
  3018         if (meth.name==names.init) {
  3019             // We are seeing a this(...) or super(...) constructor call.
  3020             // If an access constructor is used, append null as a last argument.
  3021             Symbol constructor = accessConstructor(tree.pos(), meth);
  3022             if (constructor != meth) {
  3023                 tree.args = tree.args.append(makeNull());
  3024                 TreeInfo.setSymbol(tree.meth, constructor);
  3027             // If we are calling a constructor of a local class, add
  3028             // free variables after explicit constructor arguments.
  3029             ClassSymbol c = (ClassSymbol)constructor.owner;
  3030             if (c.isLocal()) {
  3031                 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
  3034             // If we are calling a constructor of an enum class, pass
  3035             // along the name and ordinal arguments
  3036             if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) {
  3037                 List<JCVariableDecl> params = currentMethodDef.params;
  3038                 if (currentMethodSym.owner.hasOuterInstance())
  3039                     params = params.tail; // drop this$n
  3040                 tree.args = tree.args
  3041                     .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal
  3042                     .prepend(make.Ident(params.head.sym)); // name
  3045             // If we are calling a constructor of a class with an outer
  3046             // instance, and the call
  3047             // is qualified, pass qualifier as first argument in front of
  3048             // the explicit constructor arguments. If the call
  3049             // is not qualified, pass the correct outer instance as
  3050             // first argument.
  3051             if (c.hasOuterInstance()) {
  3052                 JCExpression thisArg;
  3053                 if (tree.meth.hasTag(SELECT)) {
  3054                     thisArg = attr.
  3055                         makeNullCheck(translate(((JCFieldAccess) tree.meth).selected));
  3056                     tree.meth = make.Ident(constructor);
  3057                     ((JCIdent) tree.meth).name = methName;
  3058                 } else if (c.isLocal() || methName == names._this){
  3059                     // local class or this() call
  3060                     thisArg = makeThis(tree.meth.pos(), c.type.getEnclosingType().tsym);
  3061                 } else {
  3062                     // super() call of nested class - never pick 'this'
  3063                     thisArg = makeOwnerThisN(tree.meth.pos(), c, false);
  3065                 tree.args = tree.args.prepend(thisArg);
  3067         } else {
  3068             // We are seeing a normal method invocation; translate this as usual.
  3069             tree.meth = translate(tree.meth);
  3071             // If the translated method itself is an Apply tree, we are
  3072             // seeing an access method invocation. In this case, append
  3073             // the method arguments to the arguments of the access method.
  3074             if (tree.meth.hasTag(APPLY)) {
  3075                 JCMethodInvocation app = (JCMethodInvocation)tree.meth;
  3076                 app.args = tree.args.prependList(app.args);
  3077                 result = app;
  3078                 return;
  3081         result = tree;
  3084     List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) {
  3085         List<JCExpression> args = _args;
  3086         if (parameters.isEmpty()) return args;
  3087         boolean anyChanges = false;
  3088         ListBuffer<JCExpression> result = new ListBuffer<JCExpression>();
  3089         while (parameters.tail.nonEmpty()) {
  3090             JCExpression arg = translate(args.head, parameters.head);
  3091             anyChanges |= (arg != args.head);
  3092             result.append(arg);
  3093             args = args.tail;
  3094             parameters = parameters.tail;
  3096         Type parameter = parameters.head;
  3097         if (varargsElement != null) {
  3098             anyChanges = true;
  3099             ListBuffer<JCExpression> elems = new ListBuffer<JCExpression>();
  3100             while (args.nonEmpty()) {
  3101                 JCExpression arg = translate(args.head, varargsElement);
  3102                 elems.append(arg);
  3103                 args = args.tail;
  3105             JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement),
  3106                                                List.<JCExpression>nil(),
  3107                                                elems.toList());
  3108             boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass);
  3109             result.append(boxedArgs);
  3110         } else {
  3111             if (args.length() != 1) throw new AssertionError(args);
  3112             JCExpression arg = translate(args.head, parameter);
  3113             anyChanges |= (arg != args.head);
  3114             result.append(arg);
  3115             if (!anyChanges) return _args;
  3117         return result.toList();
  3120     /** Expand a boxing or unboxing conversion if needed. */
  3121     @SuppressWarnings("unchecked") // XXX unchecked
  3122     <T extends JCTree> T boxIfNeeded(T tree, Type type) {
  3123         boolean havePrimitive = tree.type.isPrimitive();
  3124         if (havePrimitive == type.isPrimitive())
  3125             return tree;
  3126         if (havePrimitive) {
  3127             Type unboxedTarget = types.unboxedType(type);
  3128             if (!unboxedTarget.hasTag(NONE)) {
  3129                 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89;
  3130                     tree.type = unboxedTarget.constType(tree.type.constValue());
  3131                 return (T)boxPrimitive((JCExpression)tree, type);
  3132             } else {
  3133                 tree = (T)boxPrimitive((JCExpression)tree);
  3135         } else {
  3136             tree = (T)unbox((JCExpression)tree, type);
  3138         return tree;
  3141     /** Box up a single primitive expression. */
  3142     JCExpression boxPrimitive(JCExpression tree) {
  3143         return boxPrimitive(tree, types.boxedClass(tree.type).type);
  3146     /** Box up a single primitive expression. */
  3147     JCExpression boxPrimitive(JCExpression tree, Type box) {
  3148         make_at(tree.pos());
  3149         if (target.boxWithConstructors()) {
  3150             Symbol ctor = lookupConstructor(tree.pos(),
  3151                                             box,
  3152                                             List.<Type>nil()
  3153                                             .prepend(tree.type));
  3154             return make.Create(ctor, List.of(tree));
  3155         } else {
  3156             Symbol valueOfSym = lookupMethod(tree.pos(),
  3157                                              names.valueOf,
  3158                                              box,
  3159                                              List.<Type>nil()
  3160                                              .prepend(tree.type));
  3161             return make.App(make.QualIdent(valueOfSym), List.of(tree));
  3165     /** Unbox an object to a primitive value. */
  3166     JCExpression unbox(JCExpression tree, Type primitive) {
  3167         Type unboxedType = types.unboxedType(tree.type);
  3168         if (unboxedType.hasTag(NONE)) {
  3169             unboxedType = primitive;
  3170             if (!unboxedType.isPrimitive())
  3171                 throw new AssertionError(unboxedType);
  3172             make_at(tree.pos());
  3173             tree = make.TypeCast(types.boxedClass(unboxedType).type, tree);
  3174         } else {
  3175             // There must be a conversion from unboxedType to primitive.
  3176             if (!types.isSubtype(unboxedType, primitive))
  3177                 throw new AssertionError(tree);
  3179         make_at(tree.pos());
  3180         Symbol valueSym = lookupMethod(tree.pos(),
  3181                                        unboxedType.tsym.name.append(names.Value), // x.intValue()
  3182                                        tree.type,
  3183                                        List.<Type>nil());
  3184         return make.App(make.Select(tree, valueSym));
  3187     /** Visitor method for parenthesized expressions.
  3188      *  If the subexpression has changed, omit the parens.
  3189      */
  3190     public void visitParens(JCParens tree) {
  3191         JCTree expr = translate(tree.expr);
  3192         result = ((expr == tree.expr) ? tree : expr);
  3195     public void visitIndexed(JCArrayAccess tree) {
  3196         tree.indexed = translate(tree.indexed);
  3197         tree.index = translate(tree.index, syms.intType);
  3198         result = tree;
  3201     public void visitAssign(JCAssign tree) {
  3202         tree.lhs = translate(tree.lhs, tree);
  3203         tree.rhs = translate(tree.rhs, tree.lhs.type);
  3205         // If translated left hand side is an Apply, we are
  3206         // seeing an access method invocation. In this case, append
  3207         // right hand side as last argument of the access method.
  3208         if (tree.lhs.hasTag(APPLY)) {
  3209             JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
  3210             app.args = List.of(tree.rhs).prependList(app.args);
  3211             result = app;
  3212         } else {
  3213             result = tree;
  3217     public void visitAssignop(final JCAssignOp tree) {
  3218         JCTree lhsAccess = access(TreeInfo.skipParens(tree.lhs));
  3219         final boolean boxingReq = !tree.lhs.type.isPrimitive() &&
  3220             tree.operator.type.getReturnType().isPrimitive();
  3222         if (boxingReq || lhsAccess.hasTag(APPLY)) {
  3223             // boxing required; need to rewrite as x = (unbox typeof x)(x op y);
  3224             // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y)
  3225             // (but without recomputing x)
  3226             JCTree newTree = abstractLval(tree.lhs, new TreeBuilder() {
  3227                     public JCTree build(final JCTree lhs) {
  3228                         JCTree.Tag newTag = tree.getTag().noAssignOp();
  3229                         // Erasure (TransTypes) can change the type of
  3230                         // tree.lhs.  However, we can still get the
  3231                         // unerased type of tree.lhs as it is stored
  3232                         // in tree.type in Attr.
  3233                         Symbol newOperator = rs.resolveBinaryOperator(tree.pos(),
  3234                                                                       newTag,
  3235                                                                       attrEnv,
  3236                                                                       tree.type,
  3237                                                                       tree.rhs.type);
  3238                         JCExpression expr = (JCExpression)lhs;
  3239                         if (expr.type != tree.type)
  3240                             expr = make.TypeCast(tree.type, expr);
  3241                         JCBinary opResult = make.Binary(newTag, expr, tree.rhs);
  3242                         opResult.operator = newOperator;
  3243                         opResult.type = newOperator.type.getReturnType();
  3244                         JCExpression newRhs = boxingReq ?
  3245                             make.TypeCast(types.unboxedType(tree.type), opResult) :
  3246                             opResult;
  3247                         return make.Assign((JCExpression)lhs, newRhs).setType(tree.type);
  3249                 });
  3250             result = translate(newTree);
  3251             return;
  3253         tree.lhs = translate(tree.lhs, tree);
  3254         tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
  3256         // If translated left hand side is an Apply, we are
  3257         // seeing an access method invocation. In this case, append
  3258         // right hand side as last argument of the access method.
  3259         if (tree.lhs.hasTag(APPLY)) {
  3260             JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
  3261             // if operation is a += on strings,
  3262             // make sure to convert argument to string
  3263             JCExpression rhs = (((OperatorSymbol)tree.operator).opcode == string_add)
  3264               ? makeString(tree.rhs)
  3265               : tree.rhs;
  3266             app.args = List.of(rhs).prependList(app.args);
  3267             result = app;
  3268         } else {
  3269             result = tree;
  3273     /** Lower a tree of the form e++ or e-- where e is an object type */
  3274     JCTree lowerBoxedPostop(final JCUnary tree) {
  3275         // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2
  3276         // or
  3277         // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2
  3278         // where OP is += or -=
  3279         final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST);
  3280         return abstractLval(tree.arg, new TreeBuilder() {
  3281                 public JCTree build(final JCTree tmp1) {
  3282                     return abstractRval(tmp1, tree.arg.type, new TreeBuilder() {
  3283                             public JCTree build(final JCTree tmp2) {
  3284                                 JCTree.Tag opcode = (tree.hasTag(POSTINC))
  3285                                     ? PLUS_ASG : MINUS_ASG;
  3286                                 JCTree lhs = cast
  3287                                     ? make.TypeCast(tree.arg.type, (JCExpression)tmp1)
  3288                                     : tmp1;
  3289                                 JCTree update = makeAssignop(opcode,
  3290                                                              lhs,
  3291                                                              make.Literal(1));
  3292                                 return makeComma(update, tmp2);
  3294                         });
  3296             });
  3299     public void visitUnary(JCUnary tree) {
  3300         boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp();
  3301         if (isUpdateOperator && !tree.arg.type.isPrimitive()) {
  3302             switch(tree.getTag()) {
  3303             case PREINC:            // ++ e
  3304                     // translate to e += 1
  3305             case PREDEC:            // -- e
  3306                     // translate to e -= 1
  3308                     JCTree.Tag opcode = (tree.hasTag(PREINC))
  3309                         ? PLUS_ASG : MINUS_ASG;
  3310                     JCAssignOp newTree = makeAssignop(opcode,
  3311                                                     tree.arg,
  3312                                                     make.Literal(1));
  3313                     result = translate(newTree, tree.type);
  3314                     return;
  3316             case POSTINC:           // e ++
  3317             case POSTDEC:           // e --
  3319                     result = translate(lowerBoxedPostop(tree), tree.type);
  3320                     return;
  3323             throw new AssertionError(tree);
  3326         tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type);
  3328         if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) {
  3329             tree.type = cfolder.fold1(bool_not, tree.arg.type);
  3332         // If translated left hand side is an Apply, we are
  3333         // seeing an access method invocation. In this case, return
  3334         // that access method invocation as result.
  3335         if (isUpdateOperator && tree.arg.hasTag(APPLY)) {
  3336             result = tree.arg;
  3337         } else {
  3338             result = tree;
  3342     public void visitBinary(JCBinary tree) {
  3343         List<Type> formals = tree.operator.type.getParameterTypes();
  3344         JCTree lhs = tree.lhs = translate(tree.lhs, formals.head);
  3345         switch (tree.getTag()) {
  3346         case OR:
  3347             if (lhs.type.isTrue()) {
  3348                 result = lhs;
  3349                 return;
  3351             if (lhs.type.isFalse()) {
  3352                 result = translate(tree.rhs, formals.tail.head);
  3353                 return;
  3355             break;
  3356         case AND:
  3357             if (lhs.type.isFalse()) {
  3358                 result = lhs;
  3359                 return;
  3361             if (lhs.type.isTrue()) {
  3362                 result = translate(tree.rhs, formals.tail.head);
  3363                 return;
  3365             break;
  3367         tree.rhs = translate(tree.rhs, formals.tail.head);
  3368         result = tree;
  3371     public void visitIdent(JCIdent tree) {
  3372         result = access(tree.sym, tree, enclOp, false);
  3375     /** Translate away the foreach loop.  */
  3376     public void visitForeachLoop(JCEnhancedForLoop tree) {
  3377         if (types.elemtype(tree.expr.type) == null)
  3378             visitIterableForeachLoop(tree);
  3379         else
  3380             visitArrayForeachLoop(tree);
  3382         // where
  3383         /**
  3384          * A statement of the form
  3386          * <pre>
  3387          *     for ( T v : arrayexpr ) stmt;
  3388          * </pre>
  3390          * (where arrayexpr is of an array type) gets translated to
  3392          * <pre>{@code
  3393          *     for ( { arraytype #arr = arrayexpr;
  3394          *             int #len = array.length;
  3395          *             int #i = 0; };
  3396          *           #i < #len; i$++ ) {
  3397          *         T v = arr$[#i];
  3398          *         stmt;
  3399          *     }
  3400          * }</pre>
  3402          * where #arr, #len, and #i are freshly named synthetic local variables.
  3403          */
  3404         private void visitArrayForeachLoop(JCEnhancedForLoop tree) {
  3405             make_at(tree.expr.pos());
  3406             VarSymbol arraycache = new VarSymbol(SYNTHETIC,
  3407                                                  names.fromString("arr" + target.syntheticNameChar()),
  3408                                                  tree.expr.type,
  3409                                                  currentMethodSym);
  3410             JCStatement arraycachedef = make.VarDef(arraycache, tree.expr);
  3411             VarSymbol lencache = new VarSymbol(SYNTHETIC,
  3412                                                names.fromString("len" + target.syntheticNameChar()),
  3413                                                syms.intType,
  3414                                                currentMethodSym);
  3415             JCStatement lencachedef = make.
  3416                 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar));
  3417             VarSymbol index = new VarSymbol(SYNTHETIC,
  3418                                             names.fromString("i" + target.syntheticNameChar()),
  3419                                             syms.intType,
  3420                                             currentMethodSym);
  3422             JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0));
  3423             indexdef.init.type = indexdef.type = syms.intType.constType(0);
  3425             List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef);
  3426             JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache));
  3428             JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index)));
  3430             Type elemtype = types.elemtype(tree.expr.type);
  3431             JCExpression loopvarinit = make.Indexed(make.Ident(arraycache),
  3432                                                     make.Ident(index)).setType(elemtype);
  3433             JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods,
  3434                                                   tree.var.name,
  3435                                                   tree.var.vartype,
  3436                                                   loopvarinit).setType(tree.var.type);
  3437             loopvardef.sym = tree.var.sym;
  3438             JCBlock body = make.
  3439                 Block(0, List.of(loopvardef, tree.body));
  3441             result = translate(make.
  3442                                ForLoop(loopinit,
  3443                                        cond,
  3444                                        List.of(step),
  3445                                        body));
  3446             patchTargets(body, tree, result);
  3448         /** Patch up break and continue targets. */
  3449         private void patchTargets(JCTree body, final JCTree src, final JCTree dest) {
  3450             class Patcher extends TreeScanner {
  3451                 public void visitBreak(JCBreak tree) {
  3452                     if (tree.target == src)
  3453                         tree.target = dest;
  3455                 public void visitContinue(JCContinue tree) {
  3456                     if (tree.target == src)
  3457                         tree.target = dest;
  3459                 public void visitClassDef(JCClassDecl tree) {}
  3461             new Patcher().scan(body);
  3463         /**
  3464          * A statement of the form
  3466          * <pre>
  3467          *     for ( T v : coll ) stmt ;
  3468          * </pre>
  3470          * (where coll implements {@code Iterable<? extends T>}) gets translated to
  3472          * <pre>{@code
  3473          *     for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) {
  3474          *         T v = (T) #i.next();
  3475          *         stmt;
  3476          *     }
  3477          * }</pre>
  3479          * where #i is a freshly named synthetic local variable.
  3480          */
  3481         private void visitIterableForeachLoop(JCEnhancedForLoop tree) {
  3482             make_at(tree.expr.pos());
  3483             Type iteratorTarget = syms.objectType;
  3484             Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type),
  3485                                               syms.iterableType.tsym);
  3486             if (iterableType.getTypeArguments().nonEmpty())
  3487                 iteratorTarget = types.erasure(iterableType.getTypeArguments().head);
  3488             Type eType = tree.expr.type;
  3489             while (eType.hasTag(TYPEVAR)) {
  3490                 eType = eType.getUpperBound();
  3492             tree.expr.type = types.erasure(eType);
  3493             if (eType.isCompound())
  3494                 tree.expr = make.TypeCast(types.erasure(iterableType), tree.expr);
  3495             Symbol iterator = lookupMethod(tree.expr.pos(),
  3496                                            names.iterator,
  3497                                            eType,
  3498                                            List.<Type>nil());
  3499             VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()),
  3500                                             types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)),
  3501                                             currentMethodSym);
  3503              JCStatement init = make.
  3504                 VarDef(itvar, make.App(make.Select(tree.expr, iterator)
  3505                      .setType(types.erasure(iterator.type))));
  3507             Symbol hasNext = lookupMethod(tree.expr.pos(),
  3508                                           names.hasNext,
  3509                                           itvar.type,
  3510                                           List.<Type>nil());
  3511             JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext));
  3512             Symbol next = lookupMethod(tree.expr.pos(),
  3513                                        names.next,
  3514                                        itvar.type,
  3515                                        List.<Type>nil());
  3516             JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next));
  3517             if (tree.var.type.isPrimitive())
  3518                 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit);
  3519             else
  3520                 vardefinit = make.TypeCast(tree.var.type, vardefinit);
  3521             JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods,
  3522                                                   tree.var.name,
  3523                                                   tree.var.vartype,
  3524                                                   vardefinit).setType(tree.var.type);
  3525             indexDef.sym = tree.var.sym;
  3526             JCBlock body = make.Block(0, List.of(indexDef, tree.body));
  3527             body.endpos = TreeInfo.endPos(tree.body);
  3528             result = translate(make.
  3529                 ForLoop(List.of(init),
  3530                         cond,
  3531                         List.<JCExpressionStatement>nil(),
  3532                         body));
  3533             patchTargets(body, tree, result);
  3536     public void visitVarDef(JCVariableDecl tree) {
  3537         MethodSymbol oldMethodSym = currentMethodSym;
  3538         tree.mods = translate(tree.mods);
  3539         tree.vartype = translate(tree.vartype);
  3540         if (currentMethodSym == null) {
  3541             // A class or instance field initializer.
  3542             currentMethodSym =
  3543                 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK,
  3544                                  names.empty, null,
  3545                                  currentClass);
  3547         if (tree.init != null) tree.init = translate(tree.init, tree.type);
  3548         result = tree;
  3549         currentMethodSym = oldMethodSym;
  3552     public void visitBlock(JCBlock tree) {
  3553         MethodSymbol oldMethodSym = currentMethodSym;
  3554         if (currentMethodSym == null) {
  3555             // Block is a static or instance initializer.
  3556             currentMethodSym =
  3557                 new MethodSymbol(tree.flags | BLOCK,
  3558                                  names.empty, null,
  3559                                  currentClass);
  3561         super.visitBlock(tree);
  3562         currentMethodSym = oldMethodSym;
  3565     public void visitDoLoop(JCDoWhileLoop tree) {
  3566         tree.body = translate(tree.body);
  3567         tree.cond = translate(tree.cond, syms.booleanType);
  3568         result = tree;
  3571     public void visitWhileLoop(JCWhileLoop tree) {
  3572         tree.cond = translate(tree.cond, syms.booleanType);
  3573         tree.body = translate(tree.body);
  3574         result = tree;
  3577     public void visitForLoop(JCForLoop tree) {
  3578         tree.init = translate(tree.init);
  3579         if (tree.cond != null)
  3580             tree.cond = translate(tree.cond, syms.booleanType);
  3581         tree.step = translate(tree.step);
  3582         tree.body = translate(tree.body);
  3583         result = tree;
  3586     public void visitReturn(JCReturn tree) {
  3587         if (tree.expr != null)
  3588             tree.expr = translate(tree.expr,
  3589                                   types.erasure(currentMethodDef
  3590                                                 .restype.type));
  3591         result = tree;
  3594     public void visitSwitch(JCSwitch tree) {
  3595         Type selsuper = types.supertype(tree.selector.type);
  3596         boolean enumSwitch = selsuper != null &&
  3597             (tree.selector.type.tsym.flags() & ENUM) != 0;
  3598         boolean stringSwitch = selsuper != null &&
  3599             types.isSameType(tree.selector.type, syms.stringType);
  3600         Type target = enumSwitch ? tree.selector.type :
  3601             (stringSwitch? syms.stringType : syms.intType);
  3602         tree.selector = translate(tree.selector, target);
  3603         tree.cases = translateCases(tree.cases);
  3604         if (enumSwitch) {
  3605             result = visitEnumSwitch(tree);
  3606         } else if (stringSwitch) {
  3607             result = visitStringSwitch(tree);
  3608         } else {
  3609             result = tree;
  3613     public JCTree visitEnumSwitch(JCSwitch tree) {
  3614         TypeSymbol enumSym = tree.selector.type.tsym;
  3615         EnumMapping map = mapForEnum(tree.pos(), enumSym);
  3616         make_at(tree.pos());
  3617         Symbol ordinalMethod = lookupMethod(tree.pos(),
  3618                                             names.ordinal,
  3619                                             tree.selector.type,
  3620                                             List.<Type>nil());
  3621         JCArrayAccess selector = make.Indexed(map.mapVar,
  3622                                         make.App(make.Select(tree.selector,
  3623                                                              ordinalMethod)));
  3624         ListBuffer<JCCase> cases = new ListBuffer<JCCase>();
  3625         for (JCCase c : tree.cases) {
  3626             if (c.pat != null) {
  3627                 VarSymbol label = (VarSymbol)TreeInfo.symbol(c.pat);
  3628                 JCLiteral pat = map.forConstant(label);
  3629                 cases.append(make.Case(pat, c.stats));
  3630             } else {
  3631                 cases.append(c);
  3634         JCSwitch enumSwitch = make.Switch(selector, cases.toList());
  3635         patchTargets(enumSwitch, tree, enumSwitch);
  3636         return enumSwitch;
  3639     public JCTree visitStringSwitch(JCSwitch tree) {
  3640         List<JCCase> caseList = tree.getCases();
  3641         int alternatives = caseList.size();
  3643         if (alternatives == 0) { // Strange but legal possibility
  3644             return make.at(tree.pos()).Exec(attr.makeNullCheck(tree.getExpression()));
  3645         } else {
  3646             /*
  3647              * The general approach used is to translate a single
  3648              * string switch statement into a series of two chained
  3649              * switch statements: the first a synthesized statement
  3650              * switching on the argument string's hash value and
  3651              * computing a string's position in the list of original
  3652              * case labels, if any, followed by a second switch on the
  3653              * computed integer value.  The second switch has the same
  3654              * code structure as the original string switch statement
  3655              * except that the string case labels are replaced with
  3656              * positional integer constants starting at 0.
  3658              * The first switch statement can be thought of as an
  3659              * inlined map from strings to their position in the case
  3660              * label list.  An alternate implementation would use an
  3661              * actual Map for this purpose, as done for enum switches.
  3663              * With some additional effort, it would be possible to
  3664              * use a single switch statement on the hash code of the
  3665              * argument, but care would need to be taken to preserve
  3666              * the proper control flow in the presence of hash
  3667              * collisions and other complications, such as
  3668              * fallthroughs.  Switch statements with one or two
  3669              * alternatives could also be specially translated into
  3670              * if-then statements to omit the computation of the hash
  3671              * code.
  3673              * The generated code assumes that the hashing algorithm
  3674              * of String is the same in the compilation environment as
  3675              * in the environment the code will run in.  The string
  3676              * hashing algorithm in the SE JDK has been unchanged
  3677              * since at least JDK 1.2.  Since the algorithm has been
  3678              * specified since that release as well, it is very
  3679              * unlikely to be changed in the future.
  3681              * Different hashing algorithms, such as the length of the
  3682              * strings or a perfect hashing algorithm over the
  3683              * particular set of case labels, could potentially be
  3684              * used instead of String.hashCode.
  3685              */
  3687             ListBuffer<JCStatement> stmtList = new ListBuffer<JCStatement>();
  3689             // Map from String case labels to their original position in
  3690             // the list of case labels.
  3691             Map<String, Integer> caseLabelToPosition =
  3692                 new LinkedHashMap<String, Integer>(alternatives + 1, 1.0f);
  3694             // Map of hash codes to the string case labels having that hashCode.
  3695             Map<Integer, Set<String>> hashToString =
  3696                 new LinkedHashMap<Integer, Set<String>>(alternatives + 1, 1.0f);
  3698             int casePosition = 0;
  3699             for(JCCase oneCase : caseList) {
  3700                 JCExpression expression = oneCase.getExpression();
  3702                 if (expression != null) { // expression for a "default" case is null
  3703                     String labelExpr = (String) expression.type.constValue();
  3704                     Integer mapping = caseLabelToPosition.put(labelExpr, casePosition);
  3705                     Assert.checkNull(mapping);
  3706                     int hashCode = labelExpr.hashCode();
  3708                     Set<String> stringSet = hashToString.get(hashCode);
  3709                     if (stringSet == null) {
  3710                         stringSet = new LinkedHashSet<String>(1, 1.0f);
  3711                         stringSet.add(labelExpr);
  3712                         hashToString.put(hashCode, stringSet);
  3713                     } else {
  3714                         boolean added = stringSet.add(labelExpr);
  3715                         Assert.check(added);
  3718                 casePosition++;
  3721             // Synthesize a switch statement that has the effect of
  3722             // mapping from a string to the integer position of that
  3723             // string in the list of case labels.  This is done by
  3724             // switching on the hashCode of the string followed by an
  3725             // if-then-else chain comparing the input for equality
  3726             // with all the case labels having that hash value.
  3728             /*
  3729              * s$ = top of stack;
  3730              * tmp$ = -1;
  3731              * switch($s.hashCode()) {
  3732              *     case caseLabel.hashCode:
  3733              *         if (s$.equals("caseLabel_1")
  3734              *           tmp$ = caseLabelToPosition("caseLabel_1");
  3735              *         else if (s$.equals("caseLabel_2"))
  3736              *           tmp$ = caseLabelToPosition("caseLabel_2");
  3737              *         ...
  3738              *         break;
  3739              * ...
  3740              * }
  3741              */
  3743             VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
  3744                                                names.fromString("s" + tree.pos + target.syntheticNameChar()),
  3745                                                syms.stringType,
  3746                                                currentMethodSym);
  3747             stmtList.append(make.at(tree.pos()).VarDef(dollar_s, tree.getExpression()).setType(dollar_s.type));
  3749             VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC,
  3750                                                  names.fromString("tmp" + tree.pos + target.syntheticNameChar()),
  3751                                                  syms.intType,
  3752                                                  currentMethodSym);
  3753             JCVariableDecl dollar_tmp_def =
  3754                 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type);
  3755             dollar_tmp_def.init.type = dollar_tmp.type = syms.intType;
  3756             stmtList.append(dollar_tmp_def);
  3757             ListBuffer<JCCase> caseBuffer = new ListBuffer<>();
  3758             // hashCode will trigger nullcheck on original switch expression
  3759             JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s),
  3760                                                        names.hashCode,
  3761                                                        List.<JCExpression>nil()).setType(syms.intType);
  3762             JCSwitch switch1 = make.Switch(hashCodeCall,
  3763                                         caseBuffer.toList());
  3764             for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) {
  3765                 int hashCode = entry.getKey();
  3766                 Set<String> stringsWithHashCode = entry.getValue();
  3767                 Assert.check(stringsWithHashCode.size() >= 1);
  3769                 JCStatement elsepart = null;
  3770                 for(String caseLabel : stringsWithHashCode ) {
  3771                     JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s),
  3772                                                                    names.equals,
  3773                                                                    List.<JCExpression>of(make.Literal(caseLabel)));
  3774                     elsepart = make.If(stringEqualsCall,
  3775                                        make.Exec(make.Assign(make.Ident(dollar_tmp),
  3776                                                              make.Literal(caseLabelToPosition.get(caseLabel))).
  3777                                                  setType(dollar_tmp.type)),
  3778                                        elsepart);
  3781                 ListBuffer<JCStatement> lb = new ListBuffer<>();
  3782                 JCBreak breakStmt = make.Break(null);
  3783                 breakStmt.target = switch1;
  3784                 lb.append(elsepart).append(breakStmt);
  3786                 caseBuffer.append(make.Case(make.Literal(hashCode), lb.toList()));
  3789             switch1.cases = caseBuffer.toList();
  3790             stmtList.append(switch1);
  3792             // Make isomorphic switch tree replacing string labels
  3793             // with corresponding integer ones from the label to
  3794             // position map.
  3796             ListBuffer<JCCase> lb = new ListBuffer<>();
  3797             JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList());
  3798             for(JCCase oneCase : caseList ) {
  3799                 // Rewire up old unlabeled break statements to the
  3800                 // replacement switch being created.
  3801                 patchTargets(oneCase, tree, switch2);
  3803                 boolean isDefault = (oneCase.getExpression() == null);
  3804                 JCExpression caseExpr;
  3805                 if (isDefault)
  3806                     caseExpr = null;
  3807                 else {
  3808                     caseExpr = make.Literal(caseLabelToPosition.get((String)TreeInfo.skipParens(oneCase.
  3809                                                                                                 getExpression()).
  3810                                                                     type.constValue()));
  3813                 lb.append(make.Case(caseExpr,
  3814                                     oneCase.getStatements()));
  3817             switch2.cases = lb.toList();
  3818             stmtList.append(switch2);
  3820             return make.Block(0L, stmtList.toList());
  3824     public void visitNewArray(JCNewArray tree) {
  3825         tree.elemtype = translate(tree.elemtype);
  3826         for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail)
  3827             if (t.head != null) t.head = translate(t.head, syms.intType);
  3828         tree.elems = translate(tree.elems, types.elemtype(tree.type));
  3829         result = tree;
  3832     public void visitSelect(JCFieldAccess tree) {
  3833         // need to special case-access of the form C.super.x
  3834         // these will always need an access method, unless C
  3835         // is a default interface subclassed by the current class.
  3836         boolean qualifiedSuperAccess =
  3837             tree.selected.hasTag(SELECT) &&
  3838             TreeInfo.name(tree.selected) == names._super &&
  3839             !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass);
  3840         tree.selected = translate(tree.selected);
  3841         if (tree.name == names._class) {
  3842             result = classOf(tree.selected);
  3844         else if (tree.name == names._super &&
  3845                 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) {
  3846             //default super call!! Not a classic qualified super call
  3847             TypeSymbol supSym = tree.selected.type.tsym;
  3848             Assert.checkNonNull(types.asSuper(currentClass.type, supSym));
  3849             result = tree;
  3851         else if (tree.name == names._this || tree.name == names._super) {
  3852             result = makeThis(tree.pos(), tree.selected.type.tsym);
  3854         else
  3855             result = access(tree.sym, tree, enclOp, qualifiedSuperAccess);
  3858     public void visitLetExpr(LetExpr tree) {
  3859         tree.defs = translateVarDefs(tree.defs);
  3860         tree.expr = translate(tree.expr, tree.type);
  3861         result = tree;
  3864     // There ought to be nothing to rewrite here;
  3865     // we don't generate code.
  3866     public void visitAnnotation(JCAnnotation tree) {
  3867         result = tree;
  3870     @Override
  3871     public void visitTry(JCTry tree) {
  3872         if (tree.resources.nonEmpty()) {
  3873             result = makeTwrTry(tree);
  3874             return;
  3877         boolean hasBody = tree.body.getStatements().nonEmpty();
  3878         boolean hasCatchers = tree.catchers.nonEmpty();
  3879         boolean hasFinally = tree.finalizer != null &&
  3880                 tree.finalizer.getStatements().nonEmpty();
  3882         if (!hasCatchers && !hasFinally) {
  3883             result = translate(tree.body);
  3884             return;
  3887         if (!hasBody) {
  3888             if (hasFinally) {
  3889                 result = translate(tree.finalizer);
  3890             } else {
  3891                 result = translate(tree.body);
  3893             return;
  3896         // no optimizations possible
  3897         super.visitTry(tree);
  3900 /**************************************************************************
  3901  * main method
  3902  *************************************************************************/
  3904     /** Translate a toplevel class and return a list consisting of
  3905      *  the translated class and translated versions of all inner classes.
  3906      *  @param env   The attribution environment current at the class definition.
  3907      *               We need this for resolving some additional symbols.
  3908      *  @param cdef  The tree representing the class definition.
  3909      */
  3910     public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) {
  3911         ListBuffer<JCTree> translated = null;
  3912         try {
  3913             attrEnv = env;
  3914             this.make = make;
  3915             endPosTable = env.toplevel.endPositions;
  3916             currentClass = null;
  3917             currentMethodDef = null;
  3918             outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null;
  3919             outermostMemberDef = null;
  3920             this.translated = new ListBuffer<JCTree>();
  3921             classdefs = new HashMap<ClassSymbol,JCClassDecl>();
  3922             actualSymbols = new HashMap<Symbol,Symbol>();
  3923             freevarCache = new HashMap<ClassSymbol,List<VarSymbol>>();
  3924             proxies = new Scope(syms.noSymbol);
  3925             twrVars = new Scope(syms.noSymbol);
  3926             outerThisStack = List.nil();
  3927             accessNums = new HashMap<Symbol,Integer>();
  3928             accessSyms = new HashMap<Symbol,MethodSymbol[]>();
  3929             accessConstrs = new HashMap<Symbol,MethodSymbol>();
  3930             accessConstrTags = List.nil();
  3931             accessed = new ListBuffer<Symbol>();
  3932             translate(cdef, (JCExpression)null);
  3933             for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail)
  3934                 makeAccessible(l.head);
  3935             for (EnumMapping map : enumSwitchMap.values())
  3936                 map.translate();
  3937             checkConflicts(this.translated.toList());
  3938             checkAccessConstructorTags();
  3939             translated = this.translated;
  3940         } finally {
  3941             // note that recursive invocations of this method fail hard
  3942             attrEnv = null;
  3943             this.make = null;
  3944             endPosTable = null;
  3945             currentClass = null;
  3946             currentMethodDef = null;
  3947             outermostClassDef = null;
  3948             outermostMemberDef = null;
  3949             this.translated = null;
  3950             classdefs = null;
  3951             actualSymbols = null;
  3952             freevarCache = null;
  3953             proxies = null;
  3954             outerThisStack = null;
  3955             accessNums = null;
  3956             accessSyms = null;
  3957             accessConstrs = null;
  3958             accessConstrTags = null;
  3959             accessed = null;
  3960             enumSwitchMap.clear();
  3961             assertionsDisabledClassCache = null;
  3963         return translated.toList();

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