TransTypes.java revision 2571:10fc81ac75b4
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2540805Smsmith
2640805Smsmithpackage com.sun.tools.javac.comp;
2784221Sdillon
2884221Sdillonimport java.util.*;
2984221Sdillon
3040805Smsmithimport com.sun.tools.javac.code.*;
3140805Smsmithimport com.sun.tools.javac.code.Symbol.*;
3280736Smpimport com.sun.tools.javac.tree.*;
3380736Smpimport com.sun.tools.javac.tree.JCTree.*;
3440805Smsmithimport com.sun.tools.javac.util.*;
3585607Smikeimport com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
3640805Smsmithimport com.sun.tools.javac.util.List;
3785607Smike
3885671Smikeimport static com.sun.tools.javac.code.Flags.*;
3985671Smikeimport static com.sun.tools.javac.code.Kinds.*;
4085607Smikeimport static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
4185671Smikeimport static com.sun.tools.javac.code.TypeTag.CLASS;
4285671Smikeimport static com.sun.tools.javac.code.TypeTag.TYPEVAR;
4385423Sasmodaiimport static com.sun.tools.javac.code.TypeTag.VOID;
4440805Smsmithimport static com.sun.tools.javac.comp.CompileStates.CompileState;
45
46/** This pass translates Generic Java to conventional Java.
47 *
48 *  <p><b>This is NOT part of any supported API.
49 *  If you write code that depends on this, you do so at your own risk.
50 *  This code and its internal interfaces are subject to change or
51 *  deletion without notice.</b>
52 */
53public class TransTypes extends TreeTranslator {
54    /** The context key for the TransTypes phase. */
55    protected static final Context.Key<TransTypes> transTypesKey = new Context.Key<>();
56
57    /** Get the instance for this context. */
58    public static TransTypes instance(Context context) {
59        TransTypes instance = context.get(transTypesKey);
60        if (instance == null)
61            instance = new TransTypes(context);
62        return instance;
63    }
64
65    private Names names;
66    private Log log;
67    private Symtab syms;
68    private TreeMaker make;
69    private Enter enter;
70    private boolean allowInterfaceBridges;
71    private Types types;
72    private final Resolve resolve;
73
74    private final CompileStates compileStates;
75
76    protected TransTypes(Context context) {
77        context.put(transTypesKey, this);
78        compileStates = CompileStates.instance(context);
79        names = Names.instance(context);
80        log = Log.instance(context);
81        syms = Symtab.instance(context);
82        enter = Enter.instance(context);
83        overridden = new HashMap<>();
84        Source source = Source.instance(context);
85        allowInterfaceBridges = source.allowDefaultMethods();
86        types = Types.instance(context);
87        make = TreeMaker.instance(context);
88        resolve = Resolve.instance(context);
89    }
90
91    /** A hashtable mapping bridge methods to the methods they override after
92     *  type erasure.
93     */
94    Map<MethodSymbol,MethodSymbol> overridden;
95
96    /** Construct an attributed tree for a cast of expression to target type,
97     *  unless it already has precisely that type.
98     *  @param tree    The expression tree.
99     *  @param target  The target type.
100     */
101    JCExpression cast(JCExpression tree, Type target) {
102        int oldpos = make.pos;
103        make.at(tree.pos);
104        if (!types.isSameType(tree.type, target)) {
105            if (!resolve.isAccessible(env, target.tsym))
106                resolve.logAccessErrorInternal(env, tree, target);
107            tree = make.TypeCast(make.Type(target), tree).setType(target);
108        }
109        make.pos = oldpos;
110        return tree;
111    }
112
113    /** Construct an attributed tree to coerce an expression to some erased
114     *  target type, unless the expression is already assignable to that type.
115     *  If target type is a constant type, use its base type instead.
116     *  @param tree    The expression tree.
117     *  @param target  The target type.
118     */
119    public JCExpression coerce(Env<AttrContext> env, JCExpression tree, Type target) {
120        Env<AttrContext> prevEnv = this.env;
121        try {
122            this.env = env;
123            return coerce(tree, target);
124        }
125        finally {
126            this.env = prevEnv;
127        }
128    }
129    JCExpression coerce(JCExpression tree, Type target) {
130        Type btarget = target.baseType();
131        if (tree.type.isPrimitive() == target.isPrimitive()) {
132            return types.isAssignable(tree.type, btarget, types.noWarnings)
133                ? tree
134                : cast(tree, btarget);
135        }
136        return tree;
137    }
138
139    /** Given an erased reference type, assume this type as the tree's type.
140     *  Then, coerce to some given target type unless target type is null.
141     *  This operation is used in situations like the following:
142     *
143     *  <pre>{@code
144     *  class Cell<A> { A value; }
145     *  ...
146     *  Cell<Integer> cell;
147     *  Integer x = cell.value;
148     *  }</pre>
149     *
150     *  Since the erasure of Cell.value is Object, but the type
151     *  of cell.value in the assignment is Integer, we need to
152     *  adjust the original type of cell.value to Object, and insert
153     *  a cast to Integer. That is, the last assignment becomes:
154     *
155     *  <pre>{@code
156     *  Integer x = (Integer)cell.value;
157     *  }</pre>
158     *
159     *  @param tree       The expression tree whose type might need adjustment.
160     *  @param erasedType The expression's type after erasure.
161     *  @param target     The target type, which is usually the erasure of the
162     *                    expression's original type.
163     */
164    JCExpression retype(JCExpression tree, Type erasedType, Type target) {
165//      System.err.println("retype " + tree + " to " + erasedType);//DEBUG
166        if (!erasedType.isPrimitive()) {
167            if (target != null && target.isPrimitive()) {
168                target = erasure(tree.type);
169            }
170            tree.type = erasedType;
171            if (target != null) {
172                return coerce(tree, target);
173            }
174        }
175        return tree;
176    }
177
178    /** Translate method argument list, casting each argument
179     *  to its corresponding type in a list of target types.
180     *  @param _args            The method argument list.
181     *  @param parameters       The list of target types.
182     *  @param varargsElement   The erasure of the varargs element type,
183     *  or null if translating a non-varargs invocation
184     */
185    <T extends JCTree> List<T> translateArgs(List<T> _args,
186                                           List<Type> parameters,
187                                           Type varargsElement) {
188        if (parameters.isEmpty()) return _args;
189        List<T> args = _args;
190        while (parameters.tail.nonEmpty()) {
191            args.head = translate(args.head, parameters.head);
192            args = args.tail;
193            parameters = parameters.tail;
194        }
195        Type parameter = parameters.head;
196        Assert.check(varargsElement != null || args.length() == 1);
197        if (varargsElement != null) {
198            while (args.nonEmpty()) {
199                args.head = translate(args.head, varargsElement);
200                args = args.tail;
201            }
202        } else {
203            args.head = translate(args.head, parameter);
204        }
205        return _args;
206    }
207
208    public <T extends JCTree> List<T> translateArgs(List<T> _args,
209                                           List<Type> parameters,
210                                           Type varargsElement,
211                                           Env<AttrContext> localEnv) {
212        Env<AttrContext> prevEnv = env;
213        try {
214            env = localEnv;
215            return translateArgs(_args, parameters, varargsElement);
216        }
217        finally {
218            env = prevEnv;
219        }
220    }
221
222    /** Add a bridge definition and enter corresponding method symbol in
223     *  local scope of origin.
224     *
225     *  @param pos     The source code position to be used for the definition.
226     *  @param meth    The method for which a bridge needs to be added
227     *  @param impl    That method's implementation (possibly the method itself)
228     *  @param origin  The class to which the bridge will be added
229     *  @param hypothetical
230     *                 True if the bridge method is not strictly necessary in the
231     *                 binary, but is represented in the symbol table to detect
232     *                 erasure clashes.
233     *  @param bridges The list buffer to which the bridge will be added
234     */
235    void addBridge(DiagnosticPosition pos,
236                   MethodSymbol meth,
237                   MethodSymbol impl,
238                   ClassSymbol origin,
239                   boolean hypothetical,
240                   ListBuffer<JCTree> bridges) {
241        make.at(pos);
242        Type origType = types.memberType(origin.type, meth);
243        Type origErasure = erasure(origType);
244
245        // Create a bridge method symbol and a bridge definition without a body.
246        Type bridgeType = meth.erasure(types);
247        long flags = impl.flags() & AccessFlags | SYNTHETIC | BRIDGE |
248                (origin.isInterface() ? DEFAULT : 0);
249        if (hypothetical) flags |= HYPOTHETICAL;
250        MethodSymbol bridge = new MethodSymbol(flags,
251                                               meth.name,
252                                               bridgeType,
253                                               origin);
254        /* once JDK-6996415 is solved it should be checked if this approach can
255         * be applied to method addOverrideBridgesIfNeeded
256         */
257        bridge.params = createBridgeParams(impl, bridge, bridgeType);
258        bridge.setAttributes(impl);
259
260        if (!hypothetical) {
261            JCMethodDecl md = make.MethodDef(bridge, null);
262
263            // The bridge calls this.impl(..), if we have an implementation
264            // in the current class, super.impl(...) otherwise.
265            JCExpression receiver = (impl.owner == origin)
266                ? make.This(origin.erasure(types))
267                : make.Super(types.supertype(origin.type).tsym.erasure(types), origin);
268
269            // The type returned from the original method.
270            Type calltype = erasure(impl.type.getReturnType());
271
272            // Construct a call of  this.impl(params), or super.impl(params),
273            // casting params and possibly results as needed.
274            JCExpression call =
275                make.Apply(
276                           null,
277                           make.Select(receiver, impl).setType(calltype),
278                           translateArgs(make.Idents(md.params), origErasure.getParameterTypes(), null))
279                .setType(calltype);
280            JCStatement stat = (origErasure.getReturnType().hasTag(VOID))
281                ? make.Exec(call)
282                : make.Return(coerce(call, bridgeType.getReturnType()));
283            md.body = make.Block(0, List.of(stat));
284
285            // Add bridge to `bridges' buffer
286            bridges.append(md);
287        }
288
289        // Add bridge to scope of enclosing class and `overridden' table.
290        origin.members().enter(bridge);
291        overridden.put(bridge, meth);
292    }
293
294    private List<VarSymbol> createBridgeParams(MethodSymbol impl, MethodSymbol bridge,
295            Type bridgeType) {
296        List<VarSymbol> bridgeParams = null;
297        if (impl.params != null) {
298            bridgeParams = List.nil();
299            List<VarSymbol> implParams = impl.params;
300            Type.MethodType mType = (Type.MethodType)bridgeType;
301            List<Type> argTypes = mType.argtypes;
302            while (implParams.nonEmpty() && argTypes.nonEmpty()) {
303                VarSymbol param = new VarSymbol(implParams.head.flags() | SYNTHETIC | PARAMETER,
304                        implParams.head.name, argTypes.head, bridge);
305                param.setAttributes(implParams.head);
306                bridgeParams = bridgeParams.append(param);
307                implParams = implParams.tail;
308                argTypes = argTypes.tail;
309            }
310        }
311        return bridgeParams;
312    }
313
314    /** Add bridge if given symbol is a non-private, non-static member
315     *  of the given class, which is either defined in the class or non-final
316     *  inherited, and one of the two following conditions holds:
317     *  1. The method's type changes in the given class, as compared to the
318     *     class where the symbol was defined, (in this case
319     *     we have extended a parameterized class with non-trivial parameters).
320     *  2. The method has an implementation with a different erased return type.
321     *     (in this case we have used co-variant returns).
322     *  If a bridge already exists in some other class, no new bridge is added.
323     *  Instead, it is checked that the bridge symbol overrides the method symbol.
324     *  (Spec ???).
325     *  todo: what about bridges for privates???
326     *
327     *  @param pos     The source code position to be used for the definition.
328     *  @param sym     The symbol for which a bridge might have to be added.
329     *  @param origin  The class in which the bridge would go.
330     *  @param bridges The list buffer to which the bridge would be added.
331     */
332    void addBridgeIfNeeded(DiagnosticPosition pos,
333                           Symbol sym,
334                           ClassSymbol origin,
335                           ListBuffer<JCTree> bridges) {
336        if (sym.kind == MTH &&
337            sym.name != names.init &&
338            (sym.flags() & (PRIVATE | STATIC)) == 0 &&
339            (sym.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) != SYNTHETIC &&
340            sym.isMemberOf(origin, types))
341        {
342            MethodSymbol meth = (MethodSymbol)sym;
343            MethodSymbol bridge = meth.binaryImplementation(origin, types);
344            MethodSymbol impl = meth.implementation(origin, types, true, overrideBridgeFilter);
345            if (bridge == null ||
346                bridge == meth ||
347                (impl != null && !bridge.owner.isSubClass(impl.owner, types))) {
348                // No bridge was added yet.
349                if (impl != null && isBridgeNeeded(meth, impl, origin.type)) {
350                    addBridge(pos, meth, impl, origin, bridge==impl, bridges);
351                } else if (impl == meth
352                           && impl.owner != origin
353                           && (impl.flags() & FINAL) == 0
354                           && (meth.flags() & (ABSTRACT|PUBLIC)) == PUBLIC
355                           && (origin.flags() & PUBLIC) > (impl.owner.flags() & PUBLIC)) {
356                    // this is to work around a horrible but permanent
357                    // reflection design error.
358                    addBridge(pos, meth, impl, origin, false, bridges);
359                }
360            } else if ((bridge.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) == SYNTHETIC) {
361                MethodSymbol other = overridden.get(bridge);
362                if (other != null && other != meth) {
363                    if (impl == null || !impl.overrides(other, origin, types, true)) {
364                        // Bridge for other symbol pair was added
365                        log.error(pos, "name.clash.same.erasure.no.override",
366                                  other, other.location(origin.type, types),
367                                  meth,  meth.location(origin.type, types));
368                    }
369                }
370            } else if (!bridge.overrides(meth, origin, types, true)) {
371                // Accidental binary override without source override.
372                if (bridge.owner == origin ||
373                    types.asSuper(bridge.owner.type, meth.owner) == null)
374                    // Don't diagnose the problem if it would already
375                    // have been reported in the superclass
376                    log.error(pos, "name.clash.same.erasure.no.override",
377                              bridge, bridge.location(origin.type, types),
378                              meth,  meth.location(origin.type, types));
379            }
380        }
381    }
382    // where
383        private Filter<Symbol> overrideBridgeFilter = new Filter<Symbol>() {
384            public boolean accepts(Symbol s) {
385                return (s.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) != SYNTHETIC;
386            }
387        };
388
389        /**
390         * @param method The symbol for which a bridge might have to be added
391         * @param impl The implementation of method
392         * @param dest The type in which the bridge would go
393         */
394        private boolean isBridgeNeeded(MethodSymbol method,
395                                       MethodSymbol impl,
396                                       Type dest) {
397            if (impl != method) {
398                // If either method or impl have different erasures as
399                // members of dest, a bridge is needed.
400                Type method_erasure = method.erasure(types);
401                if (!isSameMemberWhenErased(dest, method, method_erasure))
402                    return true;
403                Type impl_erasure = impl.erasure(types);
404                if (!isSameMemberWhenErased(dest, impl, impl_erasure))
405                    return true;
406
407                // If the erasure of the return type is different, a
408                // bridge is needed.
409                return !types.isSameType(impl_erasure.getReturnType(),
410                                         method_erasure.getReturnType());
411            } else {
412               // method and impl are the same...
413                if ((method.flags() & ABSTRACT) != 0) {
414                    // ...and abstract so a bridge is not needed.
415                    // Concrete subclasses will bridge as needed.
416                    return false;
417                }
418
419                // The erasure of the return type is always the same
420                // for the same symbol.  Reducing the three tests in
421                // the other branch to just one:
422                return !isSameMemberWhenErased(dest, method, method.erasure(types));
423            }
424        }
425        /**
426         * Lookup the method as a member of the type.  Compare the
427         * erasures.
428         * @param type the class where to look for the method
429         * @param method the method to look for in class
430         * @param erasure the erasure of method
431         */
432        private boolean isSameMemberWhenErased(Type type,
433                                               MethodSymbol method,
434                                               Type erasure) {
435            return types.isSameType(erasure(types.memberType(type, method)),
436                                    erasure);
437        }
438
439    void addBridges(DiagnosticPosition pos,
440                    TypeSymbol i,
441                    ClassSymbol origin,
442                    ListBuffer<JCTree> bridges) {
443        for (Symbol sym : i.members().getSymbols(NON_RECURSIVE))
444            addBridgeIfNeeded(pos, sym, origin, bridges);
445        for (List<Type> l = types.interfaces(i.type); l.nonEmpty(); l = l.tail)
446            addBridges(pos, l.head.tsym, origin, bridges);
447    }
448
449    /** Add all necessary bridges to some class appending them to list buffer.
450     *  @param pos     The source code position to be used for the bridges.
451     *  @param origin  The class in which the bridges go.
452     *  @param bridges The list buffer to which the bridges are added.
453     */
454    void addBridges(DiagnosticPosition pos, ClassSymbol origin, ListBuffer<JCTree> bridges) {
455        Type st = types.supertype(origin.type);
456        while (st.hasTag(CLASS)) {
457//          if (isSpecialization(st))
458            addBridges(pos, st.tsym, origin, bridges);
459            st = types.supertype(st);
460        }
461        for (List<Type> l = types.interfaces(origin.type); l.nonEmpty(); l = l.tail)
462//          if (isSpecialization(l.head))
463            addBridges(pos, l.head.tsym, origin, bridges);
464    }
465
466/* ************************************************************************
467 * Visitor methods
468 *************************************************************************/
469
470    /** Visitor argument: proto-type.
471     */
472    private Type pt;
473
474    /** Visitor method: perform a type translation on tree.
475     */
476    public <T extends JCTree> T translate(T tree, Type pt) {
477        Type prevPt = this.pt;
478        try {
479            this.pt = pt;
480            return translate(tree);
481        } finally {
482            this.pt = prevPt;
483        }
484    }
485
486    /** Visitor method: perform a type translation on list of trees.
487     */
488    public <T extends JCTree> List<T> translate(List<T> trees, Type pt) {
489        Type prevPt = this.pt;
490        List<T> res;
491        try {
492            this.pt = pt;
493            res = translate(trees);
494        } finally {
495            this.pt = prevPt;
496        }
497        return res;
498    }
499
500    public void visitClassDef(JCClassDecl tree) {
501        translateClass(tree.sym);
502        result = tree;
503    }
504
505    JCTree currentMethod = null;
506    public void visitMethodDef(JCMethodDecl tree) {
507        JCTree previousMethod = currentMethod;
508        try {
509            currentMethod = tree;
510            tree.restype = translate(tree.restype, null);
511            tree.typarams = List.nil();
512            tree.params = translateVarDefs(tree.params);
513            tree.recvparam = translate(tree.recvparam, null);
514            tree.thrown = translate(tree.thrown, null);
515            tree.body = translate(tree.body, tree.sym.erasure(types).getReturnType());
516            tree.type = erasure(tree.type);
517            result = tree;
518        } finally {
519            currentMethod = previousMethod;
520        }
521
522        // Check that we do not introduce a name clash by erasing types.
523        for (Symbol sym : tree.sym.owner.members().getSymbolsByName(tree.name)) {
524            if (sym != tree.sym &&
525                types.isSameType(erasure(sym.type), tree.type)) {
526                log.error(tree.pos(),
527                          "name.clash.same.erasure", tree.sym,
528                          sym);
529                return;
530            }
531        }
532    }
533
534    public void visitVarDef(JCVariableDecl tree) {
535        tree.vartype = translate(tree.vartype, null);
536        tree.init = translate(tree.init, tree.sym.erasure(types));
537        tree.type = erasure(tree.type);
538        result = tree;
539    }
540
541    public void visitDoLoop(JCDoWhileLoop tree) {
542        tree.body = translate(tree.body);
543        tree.cond = translate(tree.cond, syms.booleanType);
544        result = tree;
545    }
546
547    public void visitWhileLoop(JCWhileLoop tree) {
548        tree.cond = translate(tree.cond, syms.booleanType);
549        tree.body = translate(tree.body);
550        result = tree;
551    }
552
553    public void visitForLoop(JCForLoop tree) {
554        tree.init = translate(tree.init, null);
555        if (tree.cond != null)
556            tree.cond = translate(tree.cond, syms.booleanType);
557        tree.step = translate(tree.step, null);
558        tree.body = translate(tree.body);
559        result = tree;
560    }
561
562    public void visitForeachLoop(JCEnhancedForLoop tree) {
563        tree.var = translate(tree.var, null);
564        Type iterableType = tree.expr.type;
565        tree.expr = translate(tree.expr, erasure(tree.expr.type));
566        if (types.elemtype(tree.expr.type) == null)
567            tree.expr.type = iterableType; // preserve type for Lower
568        tree.body = translate(tree.body);
569        result = tree;
570    }
571
572    public void visitLambda(JCLambda tree) {
573        JCTree prevMethod = currentMethod;
574        try {
575            currentMethod = null;
576            tree.params = translate(tree.params);
577            tree.body = translate(tree.body, tree.body.type==null? null : erasure(tree.body.type));
578            tree.type = erasure(tree.type);
579            result = tree;
580        }
581        finally {
582            currentMethod = prevMethod;
583        }
584    }
585
586    public void visitSwitch(JCSwitch tree) {
587        Type selsuper = types.supertype(tree.selector.type);
588        boolean enumSwitch = selsuper != null &&
589            selsuper.tsym == syms.enumSym;
590        Type target = enumSwitch ? erasure(tree.selector.type) : syms.intType;
591        tree.selector = translate(tree.selector, target);
592        tree.cases = translateCases(tree.cases);
593        result = tree;
594    }
595
596    public void visitCase(JCCase tree) {
597        tree.pat = translate(tree.pat, null);
598        tree.stats = translate(tree.stats);
599        result = tree;
600    }
601
602    public void visitSynchronized(JCSynchronized tree) {
603        tree.lock = translate(tree.lock, erasure(tree.lock.type));
604        tree.body = translate(tree.body);
605        result = tree;
606    }
607
608    public void visitTry(JCTry tree) {
609        tree.resources = translate(tree.resources, syms.autoCloseableType);
610        tree.body = translate(tree.body);
611        tree.catchers = translateCatchers(tree.catchers);
612        tree.finalizer = translate(tree.finalizer);
613        result = tree;
614    }
615
616    public void visitConditional(JCConditional tree) {
617        tree.cond = translate(tree.cond, syms.booleanType);
618        tree.truepart = translate(tree.truepart, erasure(tree.type));
619        tree.falsepart = translate(tree.falsepart, erasure(tree.type));
620        tree.type = erasure(tree.type);
621        result = retype(tree, tree.type, pt);
622    }
623
624   public void visitIf(JCIf tree) {
625        tree.cond = translate(tree.cond, syms.booleanType);
626        tree.thenpart = translate(tree.thenpart);
627        tree.elsepart = translate(tree.elsepart);
628        result = tree;
629    }
630
631    public void visitExec(JCExpressionStatement tree) {
632        tree.expr = translate(tree.expr, null);
633        result = tree;
634    }
635
636    public void visitReturn(JCReturn tree) {
637        tree.expr = translate(tree.expr, currentMethod != null ? types.erasure(currentMethod.type).getReturnType() : null);
638        result = tree;
639    }
640
641    public void visitThrow(JCThrow tree) {
642        tree.expr = translate(tree.expr, erasure(tree.expr.type));
643        result = tree;
644    }
645
646    public void visitAssert(JCAssert tree) {
647        tree.cond = translate(tree.cond, syms.booleanType);
648        if (tree.detail != null)
649            tree.detail = translate(tree.detail, erasure(tree.detail.type));
650        result = tree;
651    }
652
653    public void visitApply(JCMethodInvocation tree) {
654        tree.meth = translate(tree.meth, null);
655        Symbol meth = TreeInfo.symbol(tree.meth);
656        Type mt = meth.erasure(types);
657        List<Type> argtypes = mt.getParameterTypes();
658        if (meth.name == names.init && meth.owner == syms.enumSym)
659            argtypes = argtypes.tail.tail;
660        if (tree.varargsElement != null)
661            tree.varargsElement = types.erasure(tree.varargsElement);
662        else
663            if (tree.args.length() != argtypes.length()) {
664                log.error(tree.pos(),
665                              "method.invoked.with.incorrect.number.arguments",
666                              tree.args.length(), argtypes.length());
667            }
668        tree.args = translateArgs(tree.args, argtypes, tree.varargsElement);
669
670        tree.type = types.erasure(tree.type);
671        // Insert casts of method invocation results as needed.
672        result = retype(tree, mt.getReturnType(), pt);
673    }
674
675    public void visitNewClass(JCNewClass tree) {
676        if (tree.encl != null)
677            tree.encl = translate(tree.encl, erasure(tree.encl.type));
678        tree.clazz = translate(tree.clazz, null);
679        if (tree.varargsElement != null)
680            tree.varargsElement = types.erasure(tree.varargsElement);
681        tree.args = translateArgs(
682            tree.args, tree.constructor.erasure(types).getParameterTypes(), tree.varargsElement);
683        tree.def = translate(tree.def, null);
684        if (tree.constructorType != null)
685            tree.constructorType = erasure(tree.constructorType);
686        tree.type = erasure(tree.type);
687        result = tree;
688    }
689
690    public void visitNewArray(JCNewArray tree) {
691        tree.elemtype = translate(tree.elemtype, null);
692        translate(tree.dims, syms.intType);
693        if (tree.type != null) {
694            tree.elems = translate(tree.elems, erasure(types.elemtype(tree.type)));
695            tree.type = erasure(tree.type);
696        } else {
697            tree.elems = translate(tree.elems, null);
698        }
699
700        result = tree;
701    }
702
703    public void visitParens(JCParens tree) {
704        tree.expr = translate(tree.expr, pt);
705        tree.type = erasure(tree.type);
706        result = tree;
707    }
708
709    public void visitAssign(JCAssign tree) {
710        tree.lhs = translate(tree.lhs, null);
711        tree.rhs = translate(tree.rhs, erasure(tree.lhs.type));
712        tree.type = erasure(tree.lhs.type);
713        result = retype(tree, tree.type, pt);
714    }
715
716    public void visitAssignop(JCAssignOp tree) {
717        tree.lhs = translate(tree.lhs, null);
718        tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
719        tree.type = erasure(tree.type);
720        result = tree;
721    }
722
723    public void visitUnary(JCUnary tree) {
724        tree.arg = translate(tree.arg, tree.operator.type.getParameterTypes().head);
725        result = tree;
726    }
727
728    public void visitBinary(JCBinary tree) {
729        tree.lhs = translate(tree.lhs, tree.operator.type.getParameterTypes().head);
730        tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
731        result = tree;
732    }
733
734    public void visitTypeCast(JCTypeCast tree) {
735        tree.clazz = translate(tree.clazz, null);
736        Type originalTarget = tree.type;
737        tree.type = erasure(tree.type);
738        tree.expr = translate(tree.expr, erasure(tree.expr.type));
739        if (originalTarget.isCompound()) {
740            Type.IntersectionClassType ict = (Type.IntersectionClassType)originalTarget;
741            for (Type c : ict.getExplicitComponents()) {
742                Type ec = erasure(c);
743                if (!types.isSameType(ec, tree.type)) {
744                    tree.expr = coerce(tree.expr, ec);
745                }
746            }
747        }
748        result = tree;
749    }
750
751    public void visitTypeTest(JCInstanceOf tree) {
752        tree.expr = translate(tree.expr, null);
753        tree.clazz = translate(tree.clazz, null);
754        result = tree;
755    }
756
757    public void visitIndexed(JCArrayAccess tree) {
758        tree.indexed = translate(tree.indexed, erasure(tree.indexed.type));
759        tree.index = translate(tree.index, syms.intType);
760
761        // Insert casts of indexed expressions as needed.
762        result = retype(tree, types.elemtype(tree.indexed.type), pt);
763    }
764
765    // There ought to be nothing to rewrite here;
766    // we don't generate code.
767    public void visitAnnotation(JCAnnotation tree) {
768        result = tree;
769    }
770
771    public void visitIdent(JCIdent tree) {
772        Type et = tree.sym.erasure(types);
773
774        // Map type variables to their bounds.
775        if (tree.sym.kind == TYP && tree.sym.type.hasTag(TYPEVAR)) {
776            result = make.at(tree.pos).Type(et);
777        } else
778        // Map constants expressions to themselves.
779        if (tree.type.constValue() != null) {
780            result = tree;
781        }
782        // Insert casts of variable uses as needed.
783        else if (tree.sym.kind == VAR) {
784            result = retype(tree, et, pt);
785        }
786        else {
787            tree.type = erasure(tree.type);
788            result = tree;
789        }
790    }
791
792    public void visitSelect(JCFieldAccess tree) {
793        Type t = tree.selected.type;
794        while (t.hasTag(TYPEVAR))
795            t = t.getUpperBound();
796        if (t.isCompound()) {
797            if ((tree.sym.flags() & IPROXY) != 0) {
798                tree.sym = ((MethodSymbol)tree.sym).
799                    implemented((TypeSymbol)tree.sym.owner, types);
800            }
801            tree.selected = coerce(
802                translate(tree.selected, erasure(tree.selected.type)),
803                erasure(tree.sym.owner.type));
804        } else
805            tree.selected = translate(tree.selected, erasure(t));
806
807        // Map constants expressions to themselves.
808        if (tree.type.constValue() != null) {
809            result = tree;
810        }
811        // Insert casts of variable uses as needed.
812        else if (tree.sym.kind == VAR) {
813            result = retype(tree, tree.sym.erasure(types), pt);
814        }
815        else {
816            tree.type = erasure(tree.type);
817            result = tree;
818        }
819    }
820
821    public void visitReference(JCMemberReference tree) {
822        tree.expr = translate(tree.expr, erasure(tree.expr.type));
823        tree.type = erasure(tree.type);
824        if (tree.varargsElement != null)
825            tree.varargsElement = erasure(tree.varargsElement);
826        result = tree;
827    }
828
829    public void visitTypeArray(JCArrayTypeTree tree) {
830        tree.elemtype = translate(tree.elemtype, null);
831        tree.type = erasure(tree.type);
832        result = tree;
833    }
834
835    /** Visitor method for parameterized types.
836     */
837    public void visitTypeApply(JCTypeApply tree) {
838        JCTree clazz = translate(tree.clazz, null);
839        result = clazz;
840    }
841
842    public void visitTypeIntersection(JCTypeIntersection tree) {
843        tree.bounds = translate(tree.bounds, null);
844        tree.type = erasure(tree.type);
845        result = tree;
846    }
847
848/**************************************************************************
849 * utility methods
850 *************************************************************************/
851
852    private Type erasure(Type t) {
853        return types.erasure(t);
854    }
855
856/**************************************************************************
857 * main method
858 *************************************************************************/
859
860    private Env<AttrContext> env;
861
862    private static final String statePreviousToFlowAssertMsg =
863            "The current compile state [%s] of class %s is previous to FLOW";
864
865    void translateClass(ClassSymbol c) {
866        Type st = types.supertype(c.type);
867        // process superclass before derived
868        if (st.hasTag(CLASS)) {
869            translateClass((ClassSymbol)st.tsym);
870        }
871
872        Env<AttrContext> myEnv = enter.getEnv(c);
873        if (myEnv == null || (c.flags_field & TYPE_TRANSLATED) != 0) {
874            return;
875        }
876        c.flags_field |= TYPE_TRANSLATED;
877
878        /*  The two assertions below are set for early detection of any attempt
879         *  to translate a class that:
880         *
881         *  1) has no compile state being it the most outer class.
882         *     We accept this condition for inner classes.
883         *
884         *  2) has a compile state which is previous to Flow state.
885         */
886        boolean envHasCompState = compileStates.get(myEnv) != null;
887        if (!envHasCompState && c.outermostClass() == c) {
888            Assert.error("No info for outermost class: " + myEnv.enclClass.sym);
889        }
890
891        if (envHasCompState &&
892                CompileState.FLOW.isAfter(compileStates.get(myEnv))) {
893            Assert.error(String.format(statePreviousToFlowAssertMsg,
894                    compileStates.get(myEnv), myEnv.enclClass.sym));
895        }
896
897        Env<AttrContext> oldEnv = env;
898        try {
899            env = myEnv;
900            // class has not been translated yet
901
902            TreeMaker savedMake = make;
903            Type savedPt = pt;
904            make = make.forToplevel(env.toplevel);
905            pt = null;
906            try {
907                JCClassDecl tree = (JCClassDecl) env.tree;
908                tree.typarams = List.nil();
909                super.visitClassDef(tree);
910                make.at(tree.pos);
911                ListBuffer<JCTree> bridges = new ListBuffer<>();
912                if (allowInterfaceBridges || (tree.sym.flags() & INTERFACE) == 0) {
913                    addBridges(tree.pos(), c, bridges);
914                }
915                tree.defs = bridges.toList().prependList(tree.defs);
916                tree.type = erasure(tree.type);
917            } finally {
918                make = savedMake;
919                pt = savedPt;
920            }
921        } finally {
922            env = oldEnv;
923        }
924    }
925
926    /** Translate a toplevel class definition.
927     *  @param cdef    The definition to be translated.
928     */
929    public JCTree translateTopLevelClass(JCTree cdef, TreeMaker make) {
930        // note that this method does NOT support recursion.
931        this.make = make;
932        pt = null;
933        return translate(cdef, null);
934    }
935}
936