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src/share/classes/com/sun/tools/javac/comp/TransTypes.java@c002fdee76fd
src/share/classes/com/sun/tools/javac/comp/TransTypes.java
Thu, 25 Oct 2012 11:09:36 -0700
- author
- jjg
- date
- Thu, 25 Oct 2012 11:09:36 -0700
- changeset 1374
- c002fdee76fd
- parent 1358
- fc123bdeddb8
- child 1380
- a65971893c50
- permissions
- -rw-r--r--
7200915: convert TypeTags from a series of small ints to an enum
Reviewed-by: jjg, mcimadamore
Contributed-by: vicente.romero@oracle.com
1 /*
2 * Copyright (c) 1999, 2012, 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.Symbol.*;
32 import com.sun.tools.javac.tree.*;
33 import com.sun.tools.javac.tree.JCTree.*;
34 import com.sun.tools.javac.util.*;
35 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
36 import com.sun.tools.javac.util.List;
38 import static com.sun.tools.javac.code.Flags.*;
39 import static com.sun.tools.javac.code.Kinds.*;
40 import static com.sun.tools.javac.code.TypeTag.CLASS;
41 import static com.sun.tools.javac.code.TypeTag.TYPEVAR;
42 import static com.sun.tools.javac.code.TypeTag.VOID;
44 /** This pass translates Generic Java to conventional Java.
45 *
46 * <p><b>This is NOT part of any supported API.
47 * If you write code that depends on this, you do so at your own risk.
48 * This code and its internal interfaces are subject to change or
49 * deletion without notice.</b>
50 */
51 public class TransTypes extends TreeTranslator {
52 /** The context key for the TransTypes phase. */
53 protected static final Context.Key<TransTypes> transTypesKey =
54 new Context.Key<TransTypes>();
56 /** Get the instance for this context. */
57 public static TransTypes instance(Context context) {
58 TransTypes instance = context.get(transTypesKey);
59 if (instance == null)
60 instance = new TransTypes(context);
61 return instance;
62 }
64 private Names names;
65 private Log log;
66 private Symtab syms;
67 private TreeMaker make;
68 private Enter enter;
69 private boolean allowEnums;
70 private Types types;
71 private final Resolve resolve;
73 /**
74 * Flag to indicate whether or not to generate bridge methods.
75 * For pre-Tiger source there is no need for bridge methods, so it
76 * can be skipped to get better performance for -source 1.4 etc.
77 */
78 private final boolean addBridges;
80 protected TransTypes(Context context) {
81 context.put(transTypesKey, this);
82 names = Names.instance(context);
83 log = Log.instance(context);
84 syms = Symtab.instance(context);
85 enter = Enter.instance(context);
86 overridden = new HashMap<MethodSymbol,MethodSymbol>();
87 Source source = Source.instance(context);
88 allowEnums = source.allowEnums();
89 addBridges = source.addBridges();
90 types = Types.instance(context);
91 make = TreeMaker.instance(context);
92 resolve = Resolve.instance(context);
93 }
95 /** A hashtable mapping bridge methods to the methods they override after
96 * type erasure.
97 */
98 Map<MethodSymbol,MethodSymbol> overridden;
100 /** Construct an attributed tree for a cast of expression to target type,
101 * unless it already has precisely that type.
102 * @param tree The expression tree.
103 * @param target The target type.
104 */
105 JCExpression cast(JCExpression tree, Type target) {
106 int oldpos = make.pos;
107 make.at(tree.pos);
108 if (!types.isSameType(tree.type, target)) {
109 if (!resolve.isAccessible(env, target.tsym))
110 resolve.logAccessErrorInternal(env, tree, target);
111 tree = make.TypeCast(make.Type(target), tree).setType(target);
112 }
113 make.pos = oldpos;
114 return tree;
115 }
117 /** Construct an attributed tree to coerce an expression to some erased
118 * target type, unless the expression is already assignable to that type.
119 * If target type is a constant type, use its base type instead.
120 * @param tree The expression tree.
121 * @param target The target type.
122 */
123 JCExpression coerce(JCExpression tree, Type target) {
124 Type btarget = target.baseType();
125 if (tree.type.isPrimitive() == target.isPrimitive()) {
126 return types.isAssignable(tree.type, btarget, Warner.noWarnings)
127 ? tree
128 : cast(tree, btarget);
129 }
130 return tree;
131 }
133 /** Given an erased reference type, assume this type as the tree's type.
134 * Then, coerce to some given target type unless target type is null.
135 * This operation is used in situations like the following:
136 *
137 * <pre>{@code
138 * class Cell<A> { A value; }
139 * ...
140 * Cell<Integer> cell;
141 * Integer x = cell.value;
142 * }</pre>
143 *
144 * Since the erasure of Cell.value is Object, but the type
145 * of cell.value in the assignment is Integer, we need to
146 * adjust the original type of cell.value to Object, and insert
147 * a cast to Integer. That is, the last assignment becomes:
148 *
149 * <pre>{@code
150 * Integer x = (Integer)cell.value;
151 * }</pre>
152 *
153 * @param tree The expression tree whose type might need adjustment.
154 * @param erasedType The expression's type after erasure.
155 * @param target The target type, which is usually the erasure of the
156 * expression's original type.
157 */
158 JCExpression retype(JCExpression tree, Type erasedType, Type target) {
159 // System.err.println("retype " + tree + " to " + erasedType);//DEBUG
160 if (!erasedType.isPrimitive()) {
161 if (target != null && target.isPrimitive())
162 target = erasure(tree.type);
163 tree.type = erasedType;
164 if (target != null) return coerce(tree, target);
165 }
166 return tree;
167 }
169 /** Translate method argument list, casting each argument
170 * to its corresponding type in a list of target types.
171 * @param _args The method argument list.
172 * @param parameters The list of target types.
173 * @param varargsElement The erasure of the varargs element type,
174 * or null if translating a non-varargs invocation
175 */
176 <T extends JCTree> List<T> translateArgs(List<T> _args,
177 List<Type> parameters,
178 Type varargsElement) {
179 if (parameters.isEmpty()) return _args;
180 List<T> args = _args;
181 while (parameters.tail.nonEmpty()) {
182 args.head = translate(args.head, parameters.head);
183 args = args.tail;
184 parameters = parameters.tail;
185 }
186 Type parameter = parameters.head;
187 Assert.check(varargsElement != null || args.length() == 1);
188 if (varargsElement != null) {
189 while (args.nonEmpty()) {
190 args.head = translate(args.head, varargsElement);
191 args = args.tail;
192 }
193 } else {
194 args.head = translate(args.head, parameter);
195 }
196 return _args;
197 }
199 /** Add a bridge definition and enter corresponding method symbol in
200 * local scope of origin.
201 *
202 * @param pos The source code position to be used for the definition.
203 * @param meth The method for which a bridge needs to be added
204 * @param impl That method's implementation (possibly the method itself)
205 * @param origin The class to which the bridge will be added
206 * @param hypothetical
207 * True if the bridge method is not strictly necessary in the
208 * binary, but is represented in the symbol table to detect
209 * erasure clashes.
210 * @param bridges The list buffer to which the bridge will be added
211 */
212 void addBridge(DiagnosticPosition pos,
213 MethodSymbol meth,
214 MethodSymbol impl,
215 ClassSymbol origin,
216 boolean hypothetical,
217 ListBuffer<JCTree> bridges) {
218 make.at(pos);
219 Type origType = types.memberType(origin.type, meth);
220 Type origErasure = erasure(origType);
222 // Create a bridge method symbol and a bridge definition without a body.
223 Type bridgeType = meth.erasure(types);
224 long flags = impl.flags() & AccessFlags | SYNTHETIC | BRIDGE;
225 if (hypothetical) flags |= HYPOTHETICAL;
226 MethodSymbol bridge = new MethodSymbol(flags,
227 meth.name,
228 bridgeType,
229 origin);
230 if (!hypothetical) {
231 JCMethodDecl md = make.MethodDef(bridge, null);
233 // The bridge calls this.impl(..), if we have an implementation
234 // in the current class, super.impl(...) otherwise.
235 JCExpression receiver = (impl.owner == origin)
236 ? make.This(origin.erasure(types))
237 : make.Super(types.supertype(origin.type).tsym.erasure(types), origin);
239 // The type returned from the original method.
240 Type calltype = erasure(impl.type.getReturnType());
242 // Construct a call of this.impl(params), or super.impl(params),
243 // casting params and possibly results as needed.
244 JCExpression call =
245 make.Apply(
246 null,
247 make.Select(receiver, impl).setType(calltype),
248 translateArgs(make.Idents(md.params), origErasure.getParameterTypes(), null))
249 .setType(calltype);
250 JCStatement stat = (origErasure.getReturnType().hasTag(VOID))
251 ? make.Exec(call)
252 : make.Return(coerce(call, bridgeType.getReturnType()));
253 md.body = make.Block(0, List.of(stat));
255 // Add bridge to `bridges' buffer
256 bridges.append(md);
257 }
259 // Add bridge to scope of enclosing class and `overridden' table.
260 origin.members().enter(bridge);
261 overridden.put(bridge, meth);
262 }
264 /** Add bridge if given symbol is a non-private, non-static member
265 * of the given class, which is either defined in the class or non-final
266 * inherited, and one of the two following conditions holds:
267 * 1. The method's type changes in the given class, as compared to the
268 * class where the symbol was defined, (in this case
269 * we have extended a parameterized class with non-trivial parameters).
270 * 2. The method has an implementation with a different erased return type.
271 * (in this case we have used co-variant returns).
272 * If a bridge already exists in some other class, no new bridge is added.
273 * Instead, it is checked that the bridge symbol overrides the method symbol.
274 * (Spec ???).
275 * todo: what about bridges for privates???
276 *
277 * @param pos The source code position to be used for the definition.
278 * @param sym The symbol for which a bridge might have to be added.
279 * @param origin The class in which the bridge would go.
280 * @param bridges The list buffer to which the bridge would be added.
281 */
282 void addBridgeIfNeeded(DiagnosticPosition pos,
283 Symbol sym,
284 ClassSymbol origin,
285 ListBuffer<JCTree> bridges) {
286 if (sym.kind == MTH &&
287 sym.name != names.init &&
288 (sym.flags() & (PRIVATE | STATIC)) == 0 &&
289 (sym.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) != SYNTHETIC &&
290 sym.isMemberOf(origin, types))
291 {
292 MethodSymbol meth = (MethodSymbol)sym;
293 MethodSymbol bridge = meth.binaryImplementation(origin, types);
294 MethodSymbol impl = meth.implementation(origin, types, true, overrideBridgeFilter);
295 if (bridge == null ||
296 bridge == meth ||
297 (impl != null && !bridge.owner.isSubClass(impl.owner, types))) {
298 // No bridge was added yet.
299 if (impl != null && isBridgeNeeded(meth, impl, origin.type)) {
300 addBridge(pos, meth, impl, origin, bridge==impl, bridges);
301 } else if (impl == meth
302 && impl.owner != origin
303 && (impl.flags() & FINAL) == 0
304 && (meth.flags() & (ABSTRACT|PUBLIC)) == PUBLIC
305 && (origin.flags() & PUBLIC) > (impl.owner.flags() & PUBLIC)) {
306 // this is to work around a horrible but permanent
307 // reflection design error.
308 addBridge(pos, meth, impl, origin, false, bridges);
309 }
310 } else if ((bridge.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) == SYNTHETIC) {
311 MethodSymbol other = overridden.get(bridge);
312 if (other != null && other != meth) {
313 if (impl == null || !impl.overrides(other, origin, types, true)) {
314 // Bridge for other symbol pair was added
315 log.error(pos, "name.clash.same.erasure.no.override",
316 other, other.location(origin.type, types),
317 meth, meth.location(origin.type, types));
318 }
319 }
320 } else if (!bridge.overrides(meth, origin, types, true)) {
321 // Accidental binary override without source override.
322 if (bridge.owner == origin ||
323 types.asSuper(bridge.owner.type, meth.owner) == null)
324 // Don't diagnose the problem if it would already
325 // have been reported in the superclass
326 log.error(pos, "name.clash.same.erasure.no.override",
327 bridge, bridge.location(origin.type, types),
328 meth, meth.location(origin.type, types));
329 }
330 }
331 }
332 // where
333 Filter<Symbol> overrideBridgeFilter = new Filter<Symbol>() {
334 public boolean accepts(Symbol s) {
335 return (s.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) != SYNTHETIC;
336 }
337 };
338 /**
339 * @param method The symbol for which a bridge might have to be added
340 * @param impl The implementation of method
341 * @param dest The type in which the bridge would go
342 */
343 private boolean isBridgeNeeded(MethodSymbol method,
344 MethodSymbol impl,
345 Type dest) {
346 if (impl != method) {
347 // If either method or impl have different erasures as
348 // members of dest, a bridge is needed.
349 Type method_erasure = method.erasure(types);
350 if (!isSameMemberWhenErased(dest, method, method_erasure))
351 return true;
352 Type impl_erasure = impl.erasure(types);
353 if (!isSameMemberWhenErased(dest, impl, impl_erasure))
354 return true;
356 // If the erasure of the return type is different, a
357 // bridge is needed.
358 return !types.isSameType(impl_erasure.getReturnType(),
359 method_erasure.getReturnType());
360 } else {
361 // method and impl are the same...
362 if ((method.flags() & ABSTRACT) != 0) {
363 // ...and abstract so a bridge is not needed.
364 // Concrete subclasses will bridge as needed.
365 return false;
366 }
368 // The erasure of the return type is always the same
369 // for the same symbol. Reducing the three tests in
370 // the other branch to just one:
371 return !isSameMemberWhenErased(dest, method, method.erasure(types));
372 }
373 }
374 /**
375 * Lookup the method as a member of the type. Compare the
376 * erasures.
377 * @param type the class where to look for the method
378 * @param method the method to look for in class
379 * @param erasure the erasure of method
380 */
381 private boolean isSameMemberWhenErased(Type type,
382 MethodSymbol method,
383 Type erasure) {
384 return types.isSameType(erasure(types.memberType(type, method)),
385 erasure);
386 }
388 void addBridges(DiagnosticPosition pos,
389 TypeSymbol i,
390 ClassSymbol origin,
391 ListBuffer<JCTree> bridges) {
392 for (Scope.Entry e = i.members().elems; e != null; e = e.sibling)
393 addBridgeIfNeeded(pos, e.sym, origin, bridges);
394 for (List<Type> l = types.interfaces(i.type); l.nonEmpty(); l = l.tail)
395 addBridges(pos, l.head.tsym, origin, bridges);
396 }
398 /** Add all necessary bridges to some class appending them to list buffer.
399 * @param pos The source code position to be used for the bridges.
400 * @param origin The class in which the bridges go.
401 * @param bridges The list buffer to which the bridges are added.
402 */
403 void addBridges(DiagnosticPosition pos, ClassSymbol origin, ListBuffer<JCTree> bridges) {
404 Type st = types.supertype(origin.type);
405 while (st.hasTag(CLASS)) {
406 // if (isSpecialization(st))
407 addBridges(pos, st.tsym, origin, bridges);
408 st = types.supertype(st);
409 }
410 for (List<Type> l = types.interfaces(origin.type); l.nonEmpty(); l = l.tail)
411 // if (isSpecialization(l.head))
412 addBridges(pos, l.head.tsym, origin, bridges);
413 }
415 /* ************************************************************************
416 * Visitor methods
417 *************************************************************************/
419 /** Visitor argument: proto-type.
420 */
421 private Type pt;
423 /** Visitor method: perform a type translation on tree.
424 */
425 public <T extends JCTree> T translate(T tree, Type pt) {
426 Type prevPt = this.pt;
427 try {
428 this.pt = pt;
429 return translate(tree);
430 } finally {
431 this.pt = prevPt;
432 }
433 }
435 /** Visitor method: perform a type translation on list of trees.
436 */
437 public <T extends JCTree> List<T> translate(List<T> trees, Type pt) {
438 Type prevPt = this.pt;
439 List<T> res;
440 try {
441 this.pt = pt;
442 res = translate(trees);
443 } finally {
444 this.pt = prevPt;
445 }
446 return res;
447 }
449 public void visitClassDef(JCClassDecl tree) {
450 translateClass(tree.sym);
451 result = tree;
452 }
454 JCMethodDecl currentMethod = null;
455 public void visitMethodDef(JCMethodDecl tree) {
456 JCMethodDecl previousMethod = currentMethod;
457 try {
458 currentMethod = tree;
459 tree.restype = translate(tree.restype, null);
460 tree.typarams = List.nil();
461 tree.params = translateVarDefs(tree.params);
462 tree.thrown = translate(tree.thrown, null);
463 tree.body = translate(tree.body, tree.sym.erasure(types).getReturnType());
464 tree.type = erasure(tree.type);
465 result = tree;
466 } finally {
467 currentMethod = previousMethod;
468 }
470 // Check that we do not introduce a name clash by erasing types.
471 for (Scope.Entry e = tree.sym.owner.members().lookup(tree.name);
472 e.sym != null;
473 e = e.next()) {
474 if (e.sym != tree.sym &&
475 types.isSameType(erasure(e.sym.type), tree.type)) {
476 log.error(tree.pos(),
477 "name.clash.same.erasure", tree.sym,
478 e.sym);
479 return;
480 }
481 }
482 }
484 public void visitVarDef(JCVariableDecl tree) {
485 tree.vartype = translate(tree.vartype, null);
486 tree.init = translate(tree.init, tree.sym.erasure(types));
487 tree.type = erasure(tree.type);
488 result = tree;
489 }
491 public void visitDoLoop(JCDoWhileLoop tree) {
492 tree.body = translate(tree.body);
493 tree.cond = translate(tree.cond, syms.booleanType);
494 result = tree;
495 }
497 public void visitWhileLoop(JCWhileLoop tree) {
498 tree.cond = translate(tree.cond, syms.booleanType);
499 tree.body = translate(tree.body);
500 result = tree;
501 }
503 public void visitForLoop(JCForLoop tree) {
504 tree.init = translate(tree.init, null);
505 if (tree.cond != null)
506 tree.cond = translate(tree.cond, syms.booleanType);
507 tree.step = translate(tree.step, null);
508 tree.body = translate(tree.body);
509 result = tree;
510 }
512 public void visitForeachLoop(JCEnhancedForLoop tree) {
513 tree.var = translate(tree.var, null);
514 Type iterableType = tree.expr.type;
515 tree.expr = translate(tree.expr, erasure(tree.expr.type));
516 if (types.elemtype(tree.expr.type) == null)
517 tree.expr.type = iterableType; // preserve type for Lower
518 tree.body = translate(tree.body);
519 result = tree;
520 }
522 public void visitSwitch(JCSwitch tree) {
523 Type selsuper = types.supertype(tree.selector.type);
524 boolean enumSwitch = selsuper != null &&
525 selsuper.tsym == syms.enumSym;
526 Type target = enumSwitch ? erasure(tree.selector.type) : syms.intType;
527 tree.selector = translate(tree.selector, target);
528 tree.cases = translateCases(tree.cases);
529 result = tree;
530 }
532 public void visitCase(JCCase tree) {
533 tree.pat = translate(tree.pat, null);
534 tree.stats = translate(tree.stats);
535 result = tree;
536 }
538 public void visitSynchronized(JCSynchronized tree) {
539 tree.lock = translate(tree.lock, erasure(tree.lock.type));
540 tree.body = translate(tree.body);
541 result = tree;
542 }
544 public void visitTry(JCTry tree) {
545 tree.resources = translate(tree.resources, syms.autoCloseableType);
546 tree.body = translate(tree.body);
547 tree.catchers = translateCatchers(tree.catchers);
548 tree.finalizer = translate(tree.finalizer);
549 result = tree;
550 }
552 public void visitConditional(JCConditional tree) {
553 tree.cond = translate(tree.cond, syms.booleanType);
554 tree.truepart = translate(tree.truepart, erasure(tree.type));
555 tree.falsepart = translate(tree.falsepart, erasure(tree.type));
556 tree.type = erasure(tree.type);
557 result = retype(tree, tree.type, pt);
558 }
560 public void visitIf(JCIf tree) {
561 tree.cond = translate(tree.cond, syms.booleanType);
562 tree.thenpart = translate(tree.thenpart);
563 tree.elsepart = translate(tree.elsepart);
564 result = tree;
565 }
567 public void visitExec(JCExpressionStatement tree) {
568 tree.expr = translate(tree.expr, null);
569 result = tree;
570 }
572 public void visitReturn(JCReturn tree) {
573 tree.expr = translate(tree.expr, currentMethod.sym.erasure(types).getReturnType());
574 result = tree;
575 }
577 public void visitThrow(JCThrow tree) {
578 tree.expr = translate(tree.expr, erasure(tree.expr.type));
579 result = tree;
580 }
582 public void visitAssert(JCAssert tree) {
583 tree.cond = translate(tree.cond, syms.booleanType);
584 if (tree.detail != null)
585 tree.detail = translate(tree.detail, erasure(tree.detail.type));
586 result = tree;
587 }
589 public void visitApply(JCMethodInvocation tree) {
590 tree.meth = translate(tree.meth, null);
591 Symbol meth = TreeInfo.symbol(tree.meth);
592 Type mt = meth.erasure(types);
593 List<Type> argtypes = mt.getParameterTypes();
594 if (allowEnums &&
595 meth.name==names.init &&
596 meth.owner == syms.enumSym)
597 argtypes = argtypes.tail.tail;
598 if (tree.varargsElement != null)
599 tree.varargsElement = types.erasure(tree.varargsElement);
600 else
601 Assert.check(tree.args.length() == argtypes.length());
602 tree.args = translateArgs(tree.args, argtypes, tree.varargsElement);
604 // Insert casts of method invocation results as needed.
605 result = retype(tree, mt.getReturnType(), pt);
606 }
608 public void visitNewClass(JCNewClass tree) {
609 if (tree.encl != null)
610 tree.encl = translate(tree.encl, erasure(tree.encl.type));
611 tree.clazz = translate(tree.clazz, null);
612 if (tree.varargsElement != null)
613 tree.varargsElement = types.erasure(tree.varargsElement);
614 tree.args = translateArgs(
615 tree.args, tree.constructor.erasure(types).getParameterTypes(), tree.varargsElement);
616 tree.def = translate(tree.def, null);
617 tree.type = erasure(tree.type);
618 result = tree;
619 }
621 public void visitNewArray(JCNewArray tree) {
622 tree.elemtype = translate(tree.elemtype, null);
623 translate(tree.dims, syms.intType);
624 if (tree.type != null) {
625 tree.elems = translate(tree.elems, erasure(types.elemtype(tree.type)));
626 tree.type = erasure(tree.type);
627 } else {
628 tree.elems = translate(tree.elems, null);
629 }
631 result = tree;
632 }
634 @Override
635 public void visitLambda(JCLambda tree) {
636 Assert.error("Translation of lambda expression not supported yet");
637 }
639 @Override
640 public void visitReference(JCMemberReference tree) {
641 Assert.error("Translation of method reference not supported yet");
642 }
644 public void visitParens(JCParens tree) {
645 tree.expr = translate(tree.expr, pt);
646 tree.type = erasure(tree.type);
647 result = tree;
648 }
650 public void visitAssign(JCAssign tree) {
651 tree.lhs = translate(tree.lhs, null);
652 tree.rhs = translate(tree.rhs, erasure(tree.lhs.type));
653 tree.type = erasure(tree.type);
654 result = tree;
655 }
657 public void visitAssignop(JCAssignOp tree) {
658 tree.lhs = translate(tree.lhs, null);
659 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
660 tree.type = erasure(tree.type);
661 result = tree;
662 }
664 public void visitUnary(JCUnary tree) {
665 tree.arg = translate(tree.arg, tree.operator.type.getParameterTypes().head);
666 result = tree;
667 }
669 public void visitBinary(JCBinary tree) {
670 tree.lhs = translate(tree.lhs, tree.operator.type.getParameterTypes().head);
671 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
672 result = tree;
673 }
675 public void visitTypeCast(JCTypeCast tree) {
676 tree.clazz = translate(tree.clazz, null);
677 tree.type = erasure(tree.type);
678 tree.expr = translate(tree.expr, tree.type);
679 result = tree;
680 }
682 public void visitTypeTest(JCInstanceOf tree) {
683 tree.expr = translate(tree.expr, null);
684 tree.clazz = translate(tree.clazz, null);
685 result = tree;
686 }
688 public void visitIndexed(JCArrayAccess tree) {
689 tree.indexed = translate(tree.indexed, erasure(tree.indexed.type));
690 tree.index = translate(tree.index, syms.intType);
692 // Insert casts of indexed expressions as needed.
693 result = retype(tree, types.elemtype(tree.indexed.type), pt);
694 }
696 // There ought to be nothing to rewrite here;
697 // we don't generate code.
698 public void visitAnnotation(JCAnnotation tree) {
699 result = tree;
700 }
702 public void visitIdent(JCIdent tree) {
703 Type et = tree.sym.erasure(types);
705 // Map type variables to their bounds.
706 if (tree.sym.kind == TYP && tree.sym.type.hasTag(TYPEVAR)) {
707 result = make.at(tree.pos).Type(et);
708 } else
709 // Map constants expressions to themselves.
710 if (tree.type.constValue() != null) {
711 result = tree;
712 }
713 // Insert casts of variable uses as needed.
714 else if (tree.sym.kind == VAR) {
715 result = retype(tree, et, pt);
716 }
717 else {
718 tree.type = erasure(tree.type);
719 result = tree;
720 }
721 }
723 public void visitSelect(JCFieldAccess tree) {
724 Type t = tree.selected.type;
725 while (t.hasTag(TYPEVAR))
726 t = t.getUpperBound();
727 if (t.isCompound()) {
728 if ((tree.sym.flags() & IPROXY) != 0) {
729 tree.sym = ((MethodSymbol)tree.sym).
730 implemented((TypeSymbol)tree.sym.owner, types);
731 }
732 tree.selected = coerce(
733 translate(tree.selected, erasure(tree.selected.type)),
734 erasure(tree.sym.owner.type));
735 } else
736 tree.selected = translate(tree.selected, erasure(t));
738 // Map constants expressions to themselves.
739 if (tree.type.constValue() != null) {
740 result = tree;
741 }
742 // Insert casts of variable uses as needed.
743 else if (tree.sym.kind == VAR) {
744 result = retype(tree, tree.sym.erasure(types), pt);
745 }
746 else {
747 tree.type = erasure(tree.type);
748 result = tree;
749 }
750 }
752 public void visitTypeArray(JCArrayTypeTree tree) {
753 tree.elemtype = translate(tree.elemtype, null);
754 tree.type = erasure(tree.type);
755 result = tree;
756 }
758 /** Visitor method for parameterized types.
759 */
760 public void visitTypeApply(JCTypeApply tree) {
761 JCTree clazz = translate(tree.clazz, null);
762 result = clazz;
763 }
765 /**************************************************************************
766 * utility methods
767 *************************************************************************/
769 private Type erasure(Type t) {
770 return types.erasure(t);
771 }
773 private boolean boundsRestricted(ClassSymbol c) {
774 Type st = types.supertype(c.type);
775 if (st.isParameterized()) {
776 List<Type> actuals = st.allparams();
777 List<Type> formals = st.tsym.type.allparams();
778 while (!actuals.isEmpty() && !formals.isEmpty()) {
779 Type actual = actuals.head;
780 Type formal = formals.head;
782 if (!types.isSameType(types.erasure(actual),
783 types.erasure(formal)))
784 return true;
786 actuals = actuals.tail;
787 formals = formals.tail;
788 }
789 }
790 return false;
791 }
793 private List<JCTree> addOverrideBridgesIfNeeded(DiagnosticPosition pos,
794 final ClassSymbol c) {
795 ListBuffer<JCTree> buf = ListBuffer.lb();
796 if (c.isInterface() || !boundsRestricted(c))
797 return buf.toList();
798 Type t = types.supertype(c.type);
799 Scope s = t.tsym.members();
800 if (s.elems != null) {
801 for (Symbol sym : s.getElements(new NeedsOverridBridgeFilter(c))) {
803 MethodSymbol m = (MethodSymbol)sym;
804 MethodSymbol member = (MethodSymbol)m.asMemberOf(c.type, types);
805 MethodSymbol impl = m.implementation(c, types, false);
807 if ((impl == null || impl.owner != c) &&
808 !types.isSameType(member.erasure(types), m.erasure(types))) {
809 addOverrideBridges(pos, m, member, c, buf);
810 }
811 }
812 }
813 return buf.toList();
814 }
815 // where
816 class NeedsOverridBridgeFilter implements Filter<Symbol> {
818 ClassSymbol c;
820 NeedsOverridBridgeFilter(ClassSymbol c) {
821 this.c = c;
822 }
823 public boolean accepts(Symbol s) {
824 return s.kind == MTH &&
825 !s.isConstructor() &&
826 s.isInheritedIn(c, types) &&
827 (s.flags() & FINAL) == 0 &&
828 (s.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) != SYNTHETIC;
829 }
830 }
832 private void addOverrideBridges(DiagnosticPosition pos,
833 MethodSymbol impl,
834 MethodSymbol member,
835 ClassSymbol c,
836 ListBuffer<JCTree> bridges) {
837 Type implErasure = impl.erasure(types);
838 long flags = (impl.flags() & AccessFlags) | SYNTHETIC | BRIDGE | OVERRIDE_BRIDGE;
839 member = new MethodSymbol(flags, member.name, member.type, c);
840 JCMethodDecl md = make.MethodDef(member, null);
841 JCExpression receiver = make.Super(types.supertype(c.type).tsym.erasure(types), c);
842 Type calltype = erasure(impl.type.getReturnType());
843 JCExpression call =
844 make.Apply(null,
845 make.Select(receiver, impl).setType(calltype),
846 translateArgs(make.Idents(md.params),
847 implErasure.getParameterTypes(), null))
848 .setType(calltype);
849 JCStatement stat = (member.getReturnType().hasTag(VOID))
850 ? make.Exec(call)
851 : make.Return(coerce(call, member.erasure(types).getReturnType()));
852 md.body = make.Block(0, List.of(stat));
853 c.members().enter(member);
854 bridges.append(md);
855 }
857 /**************************************************************************
858 * main method
859 *************************************************************************/
861 private Env<AttrContext> env;
863 void translateClass(ClassSymbol c) {
864 Type st = types.supertype(c.type);
866 // process superclass before derived
867 if (st.hasTag(CLASS))
868 translateClass((ClassSymbol)st.tsym);
870 Env<AttrContext> myEnv = enter.typeEnvs.remove(c);
871 if (myEnv == null)
872 return;
873 Env<AttrContext> oldEnv = env;
874 try {
875 env = myEnv;
876 // class has not been translated yet
878 TreeMaker savedMake = make;
879 Type savedPt = pt;
880 make = make.forToplevel(env.toplevel);
881 pt = null;
882 try {
883 JCClassDecl tree = (JCClassDecl) env.tree;
884 tree.typarams = List.nil();
885 super.visitClassDef(tree);
886 make.at(tree.pos);
887 if (addBridges) {
888 ListBuffer<JCTree> bridges = new ListBuffer<JCTree>();
889 if (false) //see CR: 6996415
890 bridges.appendList(addOverrideBridgesIfNeeded(tree, c));
891 if ((tree.sym.flags() & INTERFACE) == 0)
892 addBridges(tree.pos(), tree.sym, bridges);
893 tree.defs = bridges.toList().prependList(tree.defs);
894 }
895 tree.type = erasure(tree.type);
896 } finally {
897 make = savedMake;
898 pt = savedPt;
899 }
900 } finally {
901 env = oldEnv;
902 }
903 }
905 /** Translate a toplevel class definition.
906 * @param cdef The definition to be translated.
907 */
908 public JCTree translateTopLevelClass(JCTree cdef, TreeMaker make) {
909 // note that this method does NOT support recursion.
910 this.make = make;
911 pt = null;
912 return translate(cdef, null);
913 }
914 }
