1 /*
2 * Copyright (c) 1999, 2009, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.comp;
27
28 import java.util.*;
29
30 import com.sun.tools.javac.code.*;
31 import com.sun.tools.javac.jvm.*;
32 import com.sun.tools.javac.tree.*;
33 import com.sun.tools.javac.util.*;
34 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
35 import com.sun.tools.javac.util.List;
36
37 import com.sun.tools.javac.code.Symbol.*;
38 import com.sun.tools.javac.tree.JCTree.*;
39 import com.sun.tools.javac.code.Type.*;
40
41 import com.sun.tools.javac.jvm.Target;
42
43 import static com.sun.tools.javac.code.Flags.*;
44 import static com.sun.tools.javac.code.Kinds.*;
45 import static com.sun.tools.javac.code.TypeTags.*;
46 import static com.sun.tools.javac.jvm.ByteCodes.*;
47
48 /** This pass translates away some syntactic sugar: inner classes,
49 * class literals, assertions, foreach loops, etc.
50 *
51 * <p><b>This is NOT part of any supported API.
52 * If you write code that depends on this, you do so at your own risk.
53 * This code and its internal interfaces are subject to change or
54 * deletion without notice.</b>
55 */
56 public class Lower extends TreeTranslator {
57 protected static final Context.Key<Lower> lowerKey =
58 new Context.Key<Lower>();
59
60 public static Lower instance(Context context) {
61 Lower instance = context.get(lowerKey);
62 if (instance == null)
63 instance = new Lower(context);
64 return instance;
65 }
66
67 private Names names;
68 private Log log;
69 private Symtab syms;
70 private Resolve rs;
71 private Check chk;
72 private Attr attr;
73 private TreeMaker make;
74 private DiagnosticPosition make_pos;
75 private ClassWriter writer;
76 private ClassReader reader;
77 private ConstFold cfolder;
78 private Target target;
79 private Source source;
80 private boolean allowEnums;
81 private final Name dollarAssertionsDisabled;
82 private final Name classDollar;
83 private Types types;
84 private boolean debugLower;
85
86 protected Lower(Context context) {
87 context.put(lowerKey, this);
88 names = Names.instance(context);
89 log = Log.instance(context);
90 syms = Symtab.instance(context);
91 rs = Resolve.instance(context);
92 chk = Check.instance(context);
93 attr = Attr.instance(context);
94 make = TreeMaker.instance(context);
95 writer = ClassWriter.instance(context);
96 reader = ClassReader.instance(context);
97 cfolder = ConstFold.instance(context);
98 target = Target.instance(context);
99 source = Source.instance(context);
100 allowEnums = source.allowEnums();
101 dollarAssertionsDisabled = names.
102 fromString(target.syntheticNameChar() + "assertionsDisabled");
103 classDollar = names.
104 fromString("class" + target.syntheticNameChar());
105
106 types = Types.instance(context);
107 Options options = Options.instance(context);
108 debugLower = options.get("debuglower") != null;
109 }
110
111 /** The currently enclosing class.
112 */
113 ClassSymbol currentClass;
114
115 /** A queue of all translated classes.
116 */
117 ListBuffer<JCTree> translated;
118
119 /** Environment for symbol lookup, set by translateTopLevelClass.
120 */
121 Env<AttrContext> attrEnv;
122
123 /** A hash table mapping syntax trees to their ending source positions.
124 */
125 Map<JCTree, Integer> endPositions;
126
127 /**************************************************************************
128 * Global mappings
129 *************************************************************************/
130
131 /** A hash table mapping local classes to their definitions.
132 */
133 Map<ClassSymbol, JCClassDecl> classdefs;
134
135 /** A hash table mapping virtual accessed symbols in outer subclasses
136 * to the actually referred symbol in superclasses.
137 */
138 Map<Symbol,Symbol> actualSymbols;
139
140 /** The current method definition.
141 */
142 JCMethodDecl currentMethodDef;
143
144 /** The current method symbol.
145 */
146 MethodSymbol currentMethodSym;
147
148 /** The currently enclosing outermost class definition.
149 */
150 JCClassDecl outermostClassDef;
151
152 /** The currently enclosing outermost member definition.
153 */
154 JCTree outermostMemberDef;
155
156 /** A navigator class for assembling a mapping from local class symbols
157 * to class definition trees.
158 * There is only one case; all other cases simply traverse down the tree.
159 */
160 class ClassMap extends TreeScanner {
161
162 /** All encountered class defs are entered into classdefs table.
163 */
164 public void visitClassDef(JCClassDecl tree) {
165 classdefs.put(tree.sym, tree);
166 super.visitClassDef(tree);
167 }
168 }
169 ClassMap classMap = new ClassMap();
170
171 /** Map a class symbol to its definition.
172 * @param c The class symbol of which we want to determine the definition.
173 */
174 JCClassDecl classDef(ClassSymbol c) {
175 // First lookup the class in the classdefs table.
176 JCClassDecl def = classdefs.get(c);
177 if (def == null && outermostMemberDef != null) {
178 // If this fails, traverse outermost member definition, entering all
179 // local classes into classdefs, and try again.
180 classMap.scan(outermostMemberDef);
181 def = classdefs.get(c);
182 }
183 if (def == null) {
184 // If this fails, traverse outermost class definition, entering all
185 // local classes into classdefs, and try again.
186 classMap.scan(outermostClassDef);
187 def = classdefs.get(c);
188 }
189 return def;
190 }
191
192 /** A hash table mapping class symbols to lists of free variables.
193 * accessed by them. Only free variables of the method immediately containing
194 * a class are associated with that class.
195 */
196 Map<ClassSymbol,List<VarSymbol>> freevarCache;
197
198 /** A navigator class for collecting the free variables accessed
199 * from a local class.
200 * There is only one case; all other cases simply traverse down the tree.
201 */
202 class FreeVarCollector extends TreeScanner {
203
204 /** The owner of the local class.
205 */
206 Symbol owner;
207
208 /** The local class.
209 */
210 ClassSymbol clazz;
211
212 /** The list of owner's variables accessed from within the local class,
213 * without any duplicates.
214 */
215 List<VarSymbol> fvs;
216
217 FreeVarCollector(ClassSymbol clazz) {
218 this.clazz = clazz;
219 this.owner = clazz.owner;
220 this.fvs = List.nil();
221 }
222
223 /** Add free variable to fvs list unless it is already there.
224 */
225 private void addFreeVar(VarSymbol v) {
226 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail)
227 if (l.head == v) return;
228 fvs = fvs.prepend(v);
229 }
230
231 /** Add all free variables of class c to fvs list
232 * unless they are already there.
233 */
234 private void addFreeVars(ClassSymbol c) {
235 List<VarSymbol> fvs = freevarCache.get(c);
236 if (fvs != null) {
237 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
238 addFreeVar(l.head);
239 }
240 }
241 }
242
243 /** If tree refers to a variable in owner of local class, add it to
244 * free variables list.
245 */
246 public void visitIdent(JCIdent tree) {
247 result = tree;
248 visitSymbol(tree.sym);
249 }
250 // where
251 private void visitSymbol(Symbol _sym) {
252 Symbol sym = _sym;
253 if (sym.kind == VAR || sym.kind == MTH) {
254 while (sym != null && sym.owner != owner)
255 sym = proxies.lookup(proxyName(sym.name)).sym;
256 if (sym != null && sym.owner == owner) {
257 VarSymbol v = (VarSymbol)sym;
258 if (v.getConstValue() == null) {
259 addFreeVar(v);
260 }
261 } else {
262 if (outerThisStack.head != null &&
263 outerThisStack.head != _sym)
264 visitSymbol(outerThisStack.head);
265 }
266 }
267 }
268
269 /** If tree refers to a class instance creation expression
270 * add all free variables of the freshly created class.
271 */
272 public void visitNewClass(JCNewClass tree) {
273 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
274 addFreeVars(c);
275 if (tree.encl == null &&
276 c.hasOuterInstance() &&
277 outerThisStack.head != null)
278 visitSymbol(outerThisStack.head);
279 super.visitNewClass(tree);
280 }
281
282 /** If tree refers to a qualified this or super expression
283 * for anything but the current class, add the outer this
284 * stack as a free variable.
285 */
286 public void visitSelect(JCFieldAccess tree) {
287 if ((tree.name == names._this || tree.name == names._super) &&
288 tree.selected.type.tsym != clazz &&
289 outerThisStack.head != null)
290 visitSymbol(outerThisStack.head);
291 super.visitSelect(tree);
292 }
293
294 /** If tree refers to a superclass constructor call,
295 * add all free variables of the superclass.
296 */
297 public void visitApply(JCMethodInvocation tree) {
298 if (TreeInfo.name(tree.meth) == names._super) {
299 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner);
300 Symbol constructor = TreeInfo.symbol(tree.meth);
301 ClassSymbol c = (ClassSymbol)constructor.owner;
302 if (c.hasOuterInstance() &&
303 tree.meth.getTag() != JCTree.SELECT &&
304 outerThisStack.head != null)
305 visitSymbol(outerThisStack.head);
306 }
307 super.visitApply(tree);
308 }
309 }
310
311 /** Return the variables accessed from within a local class, which
312 * are declared in the local class' owner.
313 * (in reverse order of first access).
314 */
315 List<VarSymbol> freevars(ClassSymbol c) {
316 if ((c.owner.kind & (VAR | MTH)) != 0) {
317 List<VarSymbol> fvs = freevarCache.get(c);
318 if (fvs == null) {
319 FreeVarCollector collector = new FreeVarCollector(c);
320 collector.scan(classDef(c));
321 fvs = collector.fvs;
322 freevarCache.put(c, fvs);
323 }
324 return fvs;
325 } else {
326 return List.nil();
327 }
328 }
329
330 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<TypeSymbol,EnumMapping>();
331
332 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) {
333 EnumMapping map = enumSwitchMap.get(enumClass);
334 if (map == null)
335 enumSwitchMap.put(enumClass, map = new EnumMapping(pos, enumClass));
336 return map;
337 }
338
339 /** This map gives a translation table to be used for enum
340 * switches.
341 *
342 * <p>For each enum that appears as the type of a switch
343 * expression, we maintain an EnumMapping to assist in the
344 * translation, as exemplified by the following example:
345 *
346 * <p>we translate
347 * <pre>
348 * switch(colorExpression) {
349 * case red: stmt1;
350 * case green: stmt2;
351 * }
352 * </pre>
353 * into
354 * <pre>
355 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) {
356 * case 1: stmt1;
357 * case 2: stmt2
358 * }
359 * </pre>
360 * with the auxiliary table initialized as follows:
361 * <pre>
362 * class Outer$0 {
363 * synthetic final int[] $EnumMap$Color = new int[Color.values().length];
364 * static {
365 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {}
366 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {}
367 * }
368 * }
369 * </pre>
370 * class EnumMapping provides mapping data and support methods for this translation.
371 */
372 class EnumMapping {
373 EnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) {
374 this.forEnum = forEnum;
375 this.values = new LinkedHashMap<VarSymbol,Integer>();
376 this.pos = pos;
377 Name varName = names
378 .fromString(target.syntheticNameChar() +
379 "SwitchMap" +
380 target.syntheticNameChar() +
381 writer.xClassName(forEnum.type).toString()
382 .replace('/', '.')
383 .replace('.', target.syntheticNameChar()));
384 ClassSymbol outerCacheClass = outerCacheClass();
385 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL,
386 varName,
387 new ArrayType(syms.intType, syms.arrayClass),
388 outerCacheClass);
389 enterSynthetic(pos, mapVar, outerCacheClass.members());
390 }
391
392 DiagnosticPosition pos = null;
393
394 // the next value to use
395 int next = 1; // 0 (unused map elements) go to the default label
396
397 // the enum for which this is a map
398 final TypeSymbol forEnum;
399
400 // the field containing the map
401 final VarSymbol mapVar;
402
403 // the mapped values
404 final Map<VarSymbol,Integer> values;
405
406 JCLiteral forConstant(VarSymbol v) {
407 Integer result = values.get(v);
408 if (result == null)
409 values.put(v, result = next++);
410 return make.Literal(result);
411 }
412
413 // generate the field initializer for the map
414 void translate() {
415 make.at(pos.getStartPosition());
416 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner);
417
418 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length];
419 MethodSymbol valuesMethod = lookupMethod(pos,
420 names.values,
421 forEnum.type,
422 List.<Type>nil());
423 JCExpression size = make // Color.values().length
424 .Select(make.App(make.QualIdent(valuesMethod)),
425 syms.lengthVar);
426 JCExpression mapVarInit = make
427 .NewArray(make.Type(syms.intType), List.of(size), null)
428 .setType(new ArrayType(syms.intType, syms.arrayClass));
429
430 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {}
431 ListBuffer<JCStatement> stmts = new ListBuffer<JCStatement>();
432 Symbol ordinalMethod = lookupMethod(pos,
433 names.ordinal,
434 forEnum.type,
435 List.<Type>nil());
436 List<JCCatch> catcher = List.<JCCatch>nil()
437 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex,
438 syms.noSuchFieldErrorType,
439 syms.noSymbol),
440 null),
441 make.Block(0, List.<JCStatement>nil())));
442 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) {
443 VarSymbol enumerator = e.getKey();
444 Integer mappedValue = e.getValue();
445 JCExpression assign = make
446 .Assign(make.Indexed(mapVar,
447 make.App(make.Select(make.QualIdent(enumerator),
448 ordinalMethod))),
449 make.Literal(mappedValue))
450 .setType(syms.intType);
451 JCStatement exec = make.Exec(assign);
452 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null);
453 stmts.append(_try);
454 }
455
456 owner.defs = owner.defs
457 .prepend(make.Block(STATIC, stmts.toList()))
458 .prepend(make.VarDef(mapVar, mapVarInit));
459 }
460 }
461
462
463 /**************************************************************************
464 * Tree building blocks
465 *************************************************************************/
466
467 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching
468 * pos as make_pos, for use in diagnostics.
469 **/
470 TreeMaker make_at(DiagnosticPosition pos) {
471 make_pos = pos;
472 return make.at(pos);
473 }
474
475 /** Make an attributed tree representing a literal. This will be an
476 * Ident node in the case of boolean literals, a Literal node in all
477 * other cases.
478 * @param type The literal's type.
479 * @param value The literal's value.
480 */
481 JCExpression makeLit(Type type, Object value) {
482 return make.Literal(type.tag, value).setType(type.constType(value));
483 }
484
485 /** Make an attributed tree representing null.
486 */
487 JCExpression makeNull() {
488 return makeLit(syms.botType, null);
489 }
490
491 /** Make an attributed class instance creation expression.
492 * @param ctype The class type.
493 * @param args The constructor arguments.
494 */
495 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
496 JCNewClass tree = make.NewClass(null,
497 null, make.QualIdent(ctype.tsym), args, null);
498 tree.constructor = rs.resolveConstructor(
499 make_pos, attrEnv, ctype, TreeInfo.types(args), null, false, false);
500 tree.type = ctype;
501 return tree;
502 }
503
504 /** Make an attributed unary expression.
505 * @param optag The operators tree tag.
506 * @param arg The operator's argument.
507 */
508 JCUnary makeUnary(int optag, JCExpression arg) {
509 JCUnary tree = make.Unary(optag, arg);
510 tree.operator = rs.resolveUnaryOperator(
511 make_pos, optag, attrEnv, arg.type);
512 tree.type = tree.operator.type.getReturnType();
513 return tree;
514 }
515
516 /** Make an attributed binary expression.
517 * @param optag The operators tree tag.
518 * @param lhs The operator's left argument.
519 * @param rhs The operator's right argument.
520 */
521 JCBinary makeBinary(int optag, JCExpression lhs, JCExpression rhs) {
522 JCBinary tree = make.Binary(optag, lhs, rhs);
523 tree.operator = rs.resolveBinaryOperator(
524 make_pos, optag, attrEnv, lhs.type, rhs.type);
525 tree.type = tree.operator.type.getReturnType();
526 return tree;
527 }
528
529 /** Make an attributed assignop expression.
530 * @param optag The operators tree tag.
531 * @param lhs The operator's left argument.
532 * @param rhs The operator's right argument.
533 */
534 JCAssignOp makeAssignop(int optag, JCTree lhs, JCTree rhs) {
535 JCAssignOp tree = make.Assignop(optag, lhs, rhs);
536 tree.operator = rs.resolveBinaryOperator(
537 make_pos, tree.getTag() - JCTree.ASGOffset, attrEnv, lhs.type, rhs.type);
538 tree.type = lhs.type;
539 return tree;
540 }
541
542 /** Convert tree into string object, unless it has already a
543 * reference type..
544 */
545 JCExpression makeString(JCExpression tree) {
546 if (tree.type.tag >= CLASS) {
547 return tree;
548 } else {
549 Symbol valueOfSym = lookupMethod(tree.pos(),
550 names.valueOf,
551 syms.stringType,
552 List.of(tree.type));
553 return make.App(make.QualIdent(valueOfSym), List.of(tree));
554 }
555 }
556
557 /** Create an empty anonymous class definition and enter and complete
558 * its symbol. Return the class definition's symbol.
559 * and create
560 * @param flags The class symbol's flags
561 * @param owner The class symbol's owner
562 */
563 ClassSymbol makeEmptyClass(long flags, ClassSymbol owner) {
564 // Create class symbol.
565 ClassSymbol c = reader.defineClass(names.empty, owner);
566 c.flatname = chk.localClassName(c);
567 c.sourcefile = owner.sourcefile;
568 c.completer = null;
569 c.members_field = new Scope(c);
570 c.flags_field = flags;
571 ClassType ctype = (ClassType) c.type;
572 ctype.supertype_field = syms.objectType;
573 ctype.interfaces_field = List.nil();
574
575 JCClassDecl odef = classDef(owner);
576
577 // Enter class symbol in owner scope and compiled table.
578 enterSynthetic(odef.pos(), c, owner.members());
579 chk.compiled.put(c.flatname, c);
580
581 // Create class definition tree.
582 JCClassDecl cdef = make.ClassDef(
583 make.Modifiers(flags), names.empty,
584 List.<JCTypeParameter>nil(),
585 null, List.<JCExpression>nil(), List.<JCTree>nil());
586 cdef.sym = c;
587 cdef.type = c.type;
588
589 // Append class definition tree to owner's definitions.
590 odef.defs = odef.defs.prepend(cdef);
591
592 return c;
593 }
594
595 /**************************************************************************
596 * Symbol manipulation utilities
597 *************************************************************************/
598
599 /** Enter a synthetic symbol in a given scope, but complain if there was already one there.
600 * @param pos Position for error reporting.
601 * @param sym The symbol.
602 * @param s The scope.
603 */
604 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, Scope s) {
605 s.enter(sym);
606 }
607
608 /** Check whether synthetic symbols generated during lowering conflict
609 * with user-defined symbols.
610 *
611 * @param translatedTrees lowered class trees
612 */
613 void checkConflicts(List<JCTree> translatedTrees) {
614 for (JCTree t : translatedTrees) {
615 t.accept(conflictsChecker);
616 }
617 }
618
619 JCTree.Visitor conflictsChecker = new TreeScanner() {
620
621 TypeSymbol currentClass;
622
623 @Override
624 public void visitMethodDef(JCMethodDecl that) {
625 chk.checkConflicts(that.pos(), that.sym, currentClass);
626 super.visitMethodDef(that);
627 }
628
629 @Override
630 public void visitVarDef(JCVariableDecl that) {
631 if (that.sym.owner.kind == TYP) {
632 chk.checkConflicts(that.pos(), that.sym, currentClass);
633 }
634 super.visitVarDef(that);
635 }
636
637 @Override
638 public void visitClassDef(JCClassDecl that) {
639 TypeSymbol prevCurrentClass = currentClass;
640 currentClass = that.sym;
641 try {
642 super.visitClassDef(that);
643 }
644 finally {
645 currentClass = prevCurrentClass;
646 }
647 }
648 };
649
650 /** Look up a synthetic name in a given scope.
651 * @param scope The scope.
652 * @param name The name.
653 */
654 private Symbol lookupSynthetic(Name name, Scope s) {
655 Symbol sym = s.lookup(name).sym;
656 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym;
657 }
658
659 /** Look up a method in a given scope.
660 */
661 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) {
662 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, null);
663 }
664
665 /** Look up a constructor.
666 */
667 private MethodSymbol lookupConstructor(DiagnosticPosition pos, Type qual, List<Type> args) {
668 return rs.resolveInternalConstructor(pos, attrEnv, qual, args, null);
669 }
670
671 /** Look up a field.
672 */
673 private VarSymbol lookupField(DiagnosticPosition pos, Type qual, Name name) {
674 return rs.resolveInternalField(pos, attrEnv, qual, name);
675 }
676
677 /** Anon inner classes are used as access constructor tags.
678 * accessConstructorTag will use an existing anon class if one is available,
679 * and synthethise a class (with makeEmptyClass) if one is not available.
680 * However, there is a small possibility that an existing class will not
681 * be generated as expected if it is inside a conditional with a constant
682 * expression. If that is found to be the case, create an empty class here.
683 */
684 private void checkAccessConstructorTags() {
685 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) {
686 ClassSymbol c = l.head;
687 if (isTranslatedClassAvailable(c))
688 continue;
689 // Create class definition tree.
690 JCClassDecl cdef = make.ClassDef(
691 make.Modifiers(STATIC | SYNTHETIC), names.empty,
692 List.<JCTypeParameter>nil(),
693 null, List.<JCExpression>nil(), List.<JCTree>nil());
694 cdef.sym = c;
695 cdef.type = c.type;
696 // add it to the list of classes to be generated
697 translated.append(cdef);
698 }
699 }
700 // where
701 private boolean isTranslatedClassAvailable(ClassSymbol c) {
702 for (JCTree tree: translated) {
703 if (tree.getTag() == JCTree.CLASSDEF
704 && ((JCClassDecl) tree).sym == c) {
705 return true;
706 }
707 }
708 return false;
709 }
710
711 /**************************************************************************
712 * Access methods
713 *************************************************************************/
714
715 /** Access codes for dereferencing, assignment,
716 * and pre/post increment/decrement.
717 * Access codes for assignment operations are determined by method accessCode
718 * below.
719 *
720 * All access codes for accesses to the current class are even.
721 * If a member of the superclass should be accessed instead (because
722 * access was via a qualified super), add one to the corresponding code
723 * for the current class, making the number odd.
724 * This numbering scheme is used by the backend to decide whether
725 * to issue an invokevirtual or invokespecial call.
726 *
727 * @see Gen.visitSelect(Select tree)
728 */
729 private static final int
730 DEREFcode = 0,
731 ASSIGNcode = 2,
732 PREINCcode = 4,
733 PREDECcode = 6,
734 POSTINCcode = 8,
735 POSTDECcode = 10,
736 FIRSTASGOPcode = 12;
737
738 /** Number of access codes
739 */
740 private static final int NCODES = accessCode(ByteCodes.lushrl) + 2;
741
742 /** A mapping from symbols to their access numbers.
743 */
744 private Map<Symbol,Integer> accessNums;
745
746 /** A mapping from symbols to an array of access symbols, indexed by
747 * access code.
748 */
749 private Map<Symbol,MethodSymbol[]> accessSyms;
750
751 /** A mapping from (constructor) symbols to access constructor symbols.
752 */
753 private Map<Symbol,MethodSymbol> accessConstrs;
754
755 /** A list of all class symbols used for access constructor tags.
756 */
757 private List<ClassSymbol> accessConstrTags;
758
759 /** A queue for all accessed symbols.
760 */
761 private ListBuffer<Symbol> accessed;
762
763 /** Map bytecode of binary operation to access code of corresponding
764 * assignment operation. This is always an even number.
765 */
766 private static int accessCode(int bytecode) {
767 if (ByteCodes.iadd <= bytecode && bytecode <= ByteCodes.lxor)
768 return (bytecode - iadd) * 2 + FIRSTASGOPcode;
769 else if (bytecode == ByteCodes.string_add)
770 return (ByteCodes.lxor + 1 - iadd) * 2 + FIRSTASGOPcode;
771 else if (ByteCodes.ishll <= bytecode && bytecode <= ByteCodes.lushrl)
772 return (bytecode - ishll + ByteCodes.lxor + 2 - iadd) * 2 + FIRSTASGOPcode;
773 else
774 return -1;
775 }
776
777 /** return access code for identifier,
778 * @param tree The tree representing the identifier use.
779 * @param enclOp The closest enclosing operation node of tree,
780 * null if tree is not a subtree of an operation.
781 */
782 private static int accessCode(JCTree tree, JCTree enclOp) {
783 if (enclOp == null)
784 return DEREFcode;
785 else if (enclOp.getTag() == JCTree.ASSIGN &&
786 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs))
787 return ASSIGNcode;
788 else if (JCTree.PREINC <= enclOp.getTag() && enclOp.getTag() <= JCTree.POSTDEC &&
789 tree == TreeInfo.skipParens(((JCUnary) enclOp).arg))
790 return (enclOp.getTag() - JCTree.PREINC) * 2 + PREINCcode;
791 else if (JCTree.BITOR_ASG <= enclOp.getTag() && enclOp.getTag() <= JCTree.MOD_ASG &&
792 tree == TreeInfo.skipParens(((JCAssignOp) enclOp).lhs))
793 return accessCode(((OperatorSymbol) ((JCAssignOp) enclOp).operator).opcode);
794 else
795 return DEREFcode;
796 }
797
798 /** Return binary operator that corresponds to given access code.
799 */
800 private OperatorSymbol binaryAccessOperator(int acode) {
801 for (Scope.Entry e = syms.predefClass.members().elems;
802 e != null;
803 e = e.sibling) {
804 if (e.sym instanceof OperatorSymbol) {
805 OperatorSymbol op = (OperatorSymbol)e.sym;
806 if (accessCode(op.opcode) == acode) return op;
807 }
808 }
809 return null;
810 }
811
812 /** Return tree tag for assignment operation corresponding
813 * to given binary operator.
814 */
815 private static int treeTag(OperatorSymbol operator) {
816 switch (operator.opcode) {
817 case ByteCodes.ior: case ByteCodes.lor:
818 return JCTree.BITOR_ASG;
819 case ByteCodes.ixor: case ByteCodes.lxor:
820 return JCTree.BITXOR_ASG;
821 case ByteCodes.iand: case ByteCodes.land:
822 return JCTree.BITAND_ASG;
823 case ByteCodes.ishl: case ByteCodes.lshl:
824 case ByteCodes.ishll: case ByteCodes.lshll:
825 return JCTree.SL_ASG;
826 case ByteCodes.ishr: case ByteCodes.lshr:
827 case ByteCodes.ishrl: case ByteCodes.lshrl:
828 return JCTree.SR_ASG;
829 case ByteCodes.iushr: case ByteCodes.lushr:
830 case ByteCodes.iushrl: case ByteCodes.lushrl:
831 return JCTree.USR_ASG;
832 case ByteCodes.iadd: case ByteCodes.ladd:
833 case ByteCodes.fadd: case ByteCodes.dadd:
834 case ByteCodes.string_add:
835 return JCTree.PLUS_ASG;
836 case ByteCodes.isub: case ByteCodes.lsub:
837 case ByteCodes.fsub: case ByteCodes.dsub:
838 return JCTree.MINUS_ASG;
839 case ByteCodes.imul: case ByteCodes.lmul:
840 case ByteCodes.fmul: case ByteCodes.dmul:
841 return JCTree.MUL_ASG;
842 case ByteCodes.idiv: case ByteCodes.ldiv:
843 case ByteCodes.fdiv: case ByteCodes.ddiv:
844 return JCTree.DIV_ASG;
845 case ByteCodes.imod: case ByteCodes.lmod:
846 case ByteCodes.fmod: case ByteCodes.dmod:
847 return JCTree.MOD_ASG;
848 default:
849 throw new AssertionError();
850 }
851 }
852
853 /** The name of the access method with number `anum' and access code `acode'.
854 */
855 Name accessName(int anum, int acode) {
856 return names.fromString(
857 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10);
858 }
859
860 /** Return access symbol for a private or protected symbol from an inner class.
861 * @param sym The accessed private symbol.
862 * @param tree The accessing tree.
863 * @param enclOp The closest enclosing operation node of tree,
864 * null if tree is not a subtree of an operation.
865 * @param protAccess Is access to a protected symbol in another
866 * package?
867 * @param refSuper Is access via a (qualified) C.super?
868 */
869 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp,
870 boolean protAccess, boolean refSuper) {
871 ClassSymbol accOwner = refSuper && protAccess
872 // For access via qualified super (T.super.x), place the
873 // access symbol on T.
874 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym
875 // Otherwise pretend that the owner of an accessed
876 // protected symbol is the enclosing class of the current
877 // class which is a subclass of the symbol's owner.
878 : accessClass(sym, protAccess, tree);
879
880 Symbol vsym = sym;
881 if (sym.owner != accOwner) {
882 vsym = sym.clone(accOwner);
883 actualSymbols.put(vsym, sym);
884 }
885
886 Integer anum // The access number of the access method.
887 = accessNums.get(vsym);
888 if (anum == null) {
889 anum = accessed.length();
890 accessNums.put(vsym, anum);
891 accessSyms.put(vsym, new MethodSymbol[NCODES]);
892 accessed.append(vsym);
893 // System.out.println("accessing " + vsym + " in " + vsym.location());
894 }
895
896 int acode; // The access code of the access method.
897 List<Type> argtypes; // The argument types of the access method.
898 Type restype; // The result type of the access method.
899 List<Type> thrown; // The thrown exceptions of the access method.
900 switch (vsym.kind) {
901 case VAR:
902 acode = accessCode(tree, enclOp);
903 if (acode >= FIRSTASGOPcode) {
904 OperatorSymbol operator = binaryAccessOperator(acode);
905 if (operator.opcode == string_add)
906 argtypes = List.of(syms.objectType);
907 else
908 argtypes = operator.type.getParameterTypes().tail;
909 } else if (acode == ASSIGNcode)
910 argtypes = List.of(vsym.erasure(types));
911 else
912 argtypes = List.nil();
913 restype = vsym.erasure(types);
914 thrown = List.nil();
915 break;
916 case MTH:
917 acode = DEREFcode;
918 argtypes = vsym.erasure(types).getParameterTypes();
919 restype = vsym.erasure(types).getReturnType();
920 thrown = vsym.type.getThrownTypes();
921 break;
922 default:
923 throw new AssertionError();
924 }
925
926 // For references via qualified super, increment acode by one,
927 // making it odd.
928 if (protAccess && refSuper) acode++;
929
930 // Instance access methods get instance as first parameter.
931 // For protected symbols this needs to be the instance as a member
932 // of the type containing the accessed symbol, not the class
933 // containing the access method.
934 if ((vsym.flags() & STATIC) == 0) {
935 argtypes = argtypes.prepend(vsym.owner.erasure(types));
936 }
937 MethodSymbol[] accessors = accessSyms.get(vsym);
938 MethodSymbol accessor = accessors[acode];
939 if (accessor == null) {
940 accessor = new MethodSymbol(
941 STATIC | SYNTHETIC,
942 accessName(anum.intValue(), acode),
943 new MethodType(argtypes, restype, thrown, syms.methodClass),
944 accOwner);
945 enterSynthetic(tree.pos(), accessor, accOwner.members());
946 accessors[acode] = accessor;
947 }
948 return accessor;
949 }
950
951 /** The qualifier to be used for accessing a symbol in an outer class.
952 * This is either C.sym or C.this.sym, depending on whether or not
953 * sym is static.
954 * @param sym The accessed symbol.
955 */
956 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) {
957 return (sym.flags() & STATIC) != 0
958 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner))
959 : makeOwnerThis(pos, sym, true);
960 }
961
962 /** Do we need an access method to reference private symbol?
963 */
964 boolean needsPrivateAccess(Symbol sym) {
965 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) {
966 return false;
967 } else if (sym.name == names.init && (sym.owner.owner.kind & (VAR | MTH)) != 0) {
968 // private constructor in local class: relax protection
969 sym.flags_field &= ~PRIVATE;
970 return false;
971 } else {
972 return true;
973 }
974 }
975
976 /** Do we need an access method to reference symbol in other package?
977 */
978 boolean needsProtectedAccess(Symbol sym, JCTree tree) {
979 if ((sym.flags() & PROTECTED) == 0 ||
980 sym.owner.owner == currentClass.owner || // fast special case
981 sym.packge() == currentClass.packge())
982 return false;
983 if (!currentClass.isSubClass(sym.owner, types))
984 return true;
985 if ((sym.flags() & STATIC) != 0 ||
986 tree.getTag() != JCTree.SELECT ||
987 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super)
988 return false;
989 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types);
990 }
991
992 /** The class in which an access method for given symbol goes.
993 * @param sym The access symbol
994 * @param protAccess Is access to a protected symbol in another
995 * package?
996 */
997 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) {
998 if (protAccess) {
999 Symbol qualifier = null;
1000 ClassSymbol c = currentClass;
1001 if (tree.getTag() == JCTree.SELECT && (sym.flags() & STATIC) == 0) {
1002 qualifier = ((JCFieldAccess) tree).selected.type.tsym;
1003 while (!qualifier.isSubClass(c, types)) {
1004 c = c.owner.enclClass();
1005 }
1006 return c;
1007 } else {
1008 while (!c.isSubClass(sym.owner, types)) {
1009 c = c.owner.enclClass();
1010 }
1011 }
1012 return c;
1013 } else {
1014 // the symbol is private
1015 return sym.owner.enclClass();
1016 }
1017 }
1018
1019 /** Ensure that identifier is accessible, return tree accessing the identifier.
1020 * @param sym The accessed symbol.
1021 * @param tree The tree referring to the symbol.
1022 * @param enclOp The closest enclosing operation node of tree,
1023 * null if tree is not a subtree of an operation.
1024 * @param refSuper Is access via a (qualified) C.super?
1025 */
1026 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) {
1027 // Access a free variable via its proxy, or its proxy's proxy
1028 while (sym.kind == VAR && sym.owner.kind == MTH &&
1029 sym.owner.enclClass() != currentClass) {
1030 // A constant is replaced by its constant value.
1031 Object cv = ((VarSymbol)sym).getConstValue();
1032 if (cv != null) {
1033 make.at(tree.pos);
1034 return makeLit(sym.type, cv);
1035 }
1036 // Otherwise replace the variable by its proxy.
1037 sym = proxies.lookup(proxyName(sym.name)).sym;
1038 assert sym != null && (sym.flags_field & FINAL) != 0;
1039 tree = make.at(tree.pos).Ident(sym);
1040 }
1041 JCExpression base = (tree.getTag() == JCTree.SELECT) ? ((JCFieldAccess) tree).selected : null;
1042 switch (sym.kind) {
1043 case TYP:
1044 if (sym.owner.kind != PCK) {
1045 // Convert type idents to
1046 // <flat name> or <package name> . <flat name>
1047 Name flatname = Convert.shortName(sym.flatName());
1048 while (base != null &&
1049 TreeInfo.symbol(base) != null &&
1050 TreeInfo.symbol(base).kind != PCK) {
1051 base = (base.getTag() == JCTree.SELECT)
1052 ? ((JCFieldAccess) base).selected
1053 : null;
1054 }
1055 if (tree.getTag() == JCTree.IDENT) {
1056 ((JCIdent) tree).name = flatname;
1057 } else if (base == null) {
1058 tree = make.at(tree.pos).Ident(sym);
1059 ((JCIdent) tree).name = flatname;
1060 } else {
1061 ((JCFieldAccess) tree).selected = base;
1062 ((JCFieldAccess) tree).name = flatname;
1063 }
1064 }
1065 break;
1066 case MTH: case VAR:
1067 if (sym.owner.kind == TYP) {
1068
1069 // Access methods are required for
1070 // - private members,
1071 // - protected members in a superclass of an
1072 // enclosing class contained in another package.
1073 // - all non-private members accessed via a qualified super.
1074 boolean protAccess = refSuper && !needsPrivateAccess(sym)
1075 || needsProtectedAccess(sym, tree);
1076 boolean accReq = protAccess || needsPrivateAccess(sym);
1077
1078 // A base has to be supplied for
1079 // - simple identifiers accessing variables in outer classes.
1080 boolean baseReq =
1081 base == null &&
1082 sym.owner != syms.predefClass &&
1083 !sym.isMemberOf(currentClass, types);
1084
1085 if (accReq || baseReq) {
1086 make.at(tree.pos);
1087
1088 // Constants are replaced by their constant value.
1089 if (sym.kind == VAR) {
1090 Object cv = ((VarSymbol)sym).getConstValue();
1091 if (cv != null) return makeLit(sym.type, cv);
1092 }
1093
1094 // Private variables and methods are replaced by calls
1095 // to their access methods.
1096 if (accReq) {
1097 List<JCExpression> args = List.nil();
1098 if ((sym.flags() & STATIC) == 0) {
1099 // Instance access methods get instance
1100 // as first parameter.
1101 if (base == null)
1102 base = makeOwnerThis(tree.pos(), sym, true);
1103 args = args.prepend(base);
1104 base = null; // so we don't duplicate code
1105 }
1106 Symbol access = accessSymbol(sym, tree,
1107 enclOp, protAccess,
1108 refSuper);
1109 JCExpression receiver = make.Select(
1110 base != null ? base : make.QualIdent(access.owner),
1111 access);
1112 return make.App(receiver, args);
1113
1114 // Other accesses to members of outer classes get a
1115 // qualifier.
1116 } else if (baseReq) {
1117 return make.at(tree.pos).Select(
1118 accessBase(tree.pos(), sym), sym).setType(tree.type);
1119 }
1120 }
1121 }
1122 }
1123 return tree;
1124 }
1125
1126 /** Ensure that identifier is accessible, return tree accessing the identifier.
1127 * @param tree The identifier tree.
1128 */
1129 JCExpression access(JCExpression tree) {
1130 Symbol sym = TreeInfo.symbol(tree);
1131 return sym == null ? tree : access(sym, tree, null, false);
1132 }
1133
1134 /** Return access constructor for a private constructor,
1135 * or the constructor itself, if no access constructor is needed.
1136 * @param pos The position to report diagnostics, if any.
1137 * @param constr The private constructor.
1138 */
1139 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) {
1140 if (needsPrivateAccess(constr)) {
1141 ClassSymbol accOwner = constr.owner.enclClass();
1142 MethodSymbol aconstr = accessConstrs.get(constr);
1143 if (aconstr == null) {
1144 List<Type> argtypes = constr.type.getParameterTypes();
1145 if ((accOwner.flags_field & ENUM) != 0)
1146 argtypes = argtypes
1147 .prepend(syms.intType)
1148 .prepend(syms.stringType);
1149 aconstr = new MethodSymbol(
1150 SYNTHETIC,
1151 names.init,
1152 new MethodType(
1153 argtypes.append(
1154 accessConstructorTag().erasure(types)),
1155 constr.type.getReturnType(),
1156 constr.type.getThrownTypes(),
1157 syms.methodClass),
1158 accOwner);
1159 enterSynthetic(pos, aconstr, accOwner.members());
1160 accessConstrs.put(constr, aconstr);
1161 accessed.append(constr);
1162 }
1163 return aconstr;
1164 } else {
1165 return constr;
1166 }
1167 }
1168
1169 /** Return an anonymous class nested in this toplevel class.
1170 */
1171 ClassSymbol accessConstructorTag() {
1172 ClassSymbol topClass = currentClass.outermostClass();
1173 Name flatname = names.fromString("" + topClass.getQualifiedName() +
1174 target.syntheticNameChar() +
1175 "1");
1176 ClassSymbol ctag = chk.compiled.get(flatname);
1177 if (ctag == null)
1178 ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass);
1179 // keep a record of all tags, to verify that all are generated as required
1180 accessConstrTags = accessConstrTags.prepend(ctag);
1181 return ctag;
1182 }
1183
1184 /** Add all required access methods for a private symbol to enclosing class.
1185 * @param sym The symbol.
1186 */
1187 void makeAccessible(Symbol sym) {
1188 JCClassDecl cdef = classDef(sym.owner.enclClass());
1189 assert cdef != null : "class def not found: " + sym + " in " + sym.owner;
1190 if (sym.name == names.init) {
1191 cdef.defs = cdef.defs.prepend(
1192 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym)));
1193 } else {
1194 MethodSymbol[] accessors = accessSyms.get(sym);
1195 for (int i = 0; i < NCODES; i++) {
1196 if (accessors[i] != null)
1197 cdef.defs = cdef.defs.prepend(
1198 accessDef(cdef.pos, sym, accessors[i], i));
1199 }
1200 }
1201 }
1202
1203 /** Construct definition of an access method.
1204 * @param pos The source code position of the definition.
1205 * @param vsym The private or protected symbol.
1206 * @param accessor The access method for the symbol.
1207 * @param acode The access code.
1208 */
1209 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) {
1210 // System.err.println("access " + vsym + " with " + accessor);//DEBUG
1211 currentClass = vsym.owner.enclClass();
1212 make.at(pos);
1213 JCMethodDecl md = make.MethodDef(accessor, null);
1214
1215 // Find actual symbol
1216 Symbol sym = actualSymbols.get(vsym);
1217 if (sym == null) sym = vsym;
1218
1219 JCExpression ref; // The tree referencing the private symbol.
1220 List<JCExpression> args; // Any additional arguments to be passed along.
1221 if ((sym.flags() & STATIC) != 0) {
1222 ref = make.Ident(sym);
1223 args = make.Idents(md.params);
1224 } else {
1225 ref = make.Select(make.Ident(md.params.head), sym);
1226 args = make.Idents(md.params.tail);
1227 }
1228 JCStatement stat; // The statement accessing the private symbol.
1229 if (sym.kind == VAR) {
1230 // Normalize out all odd access codes by taking floor modulo 2:
1231 int acode1 = acode - (acode & 1);
1232
1233 JCExpression expr; // The access method's return value.
1234 switch (acode1) {
1235 case DEREFcode:
1236 expr = ref;
1237 break;
1238 case ASSIGNcode:
1239 expr = make.Assign(ref, args.head);
1240 break;
1241 case PREINCcode: case POSTINCcode: case PREDECcode: case POSTDECcode:
1242 expr = makeUnary(
1243 ((acode1 - PREINCcode) >> 1) + JCTree.PREINC, ref);
1244 break;
1245 default:
1246 expr = make.Assignop(
1247 treeTag(binaryAccessOperator(acode1)), ref, args.head);
1248 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1);
1249 }
1250 stat = make.Return(expr.setType(sym.type));
1251 } else {
1252 stat = make.Call(make.App(ref, args));
1253 }
1254 md.body = make.Block(0, List.of(stat));
1255
1256 // Make sure all parameters, result types and thrown exceptions
1257 // are accessible.
1258 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail)
1259 l.head.vartype = access(l.head.vartype);
1260 md.restype = access(md.restype);
1261 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail)
1262 l.head = access(l.head);
1263
1264 return md;
1265 }
1266
1267 /** Construct definition of an access constructor.
1268 * @param pos The source code position of the definition.
1269 * @param constr The private constructor.
1270 * @param accessor The access method for the constructor.
1271 */
1272 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) {
1273 make.at(pos);
1274 JCMethodDecl md = make.MethodDef(accessor,
1275 accessor.externalType(types),
1276 null);
1277 JCIdent callee = make.Ident(names._this);
1278 callee.sym = constr;
1279 callee.type = constr.type;
1280 md.body =
1281 make.Block(0, List.<JCStatement>of(
1282 make.Call(
1283 make.App(
1284 callee,
1285 make.Idents(md.params.reverse().tail.reverse())))));
1286 return md;
1287 }
1288
1289 /**************************************************************************
1290 * Free variables proxies and this$n
1291 *************************************************************************/
1292
1293 /** A scope containing all free variable proxies for currently translated
1294 * class, as well as its this$n symbol (if needed).
1295 * Proxy scopes are nested in the same way classes are.
1296 * Inside a constructor, proxies and any this$n symbol are duplicated
1297 * in an additional innermost scope, where they represent the constructor
1298 * parameters.
1299 */
1300 Scope proxies;
1301
1302 /** A stack containing the this$n field of the currently translated
1303 * classes (if needed) in innermost first order.
1304 * Inside a constructor, proxies and any this$n symbol are duplicated
1305 * in an additional innermost scope, where they represent the constructor
1306 * parameters.
1307 */
1308 List<VarSymbol> outerThisStack;
1309
1310 /** The name of a free variable proxy.
1311 */
1312 Name proxyName(Name name) {
1313 return names.fromString("val" + target.syntheticNameChar() + name);
1314 }
1315
1316 /** Proxy definitions for all free variables in given list, in reverse order.
1317 * @param pos The source code position of the definition.
1318 * @param freevars The free variables.
1319 * @param owner The class in which the definitions go.
1320 */
1321 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) {
1322 long flags = FINAL | SYNTHETIC;
1323 if (owner.kind == TYP &&
1324 target.usePrivateSyntheticFields())
1325 flags |= PRIVATE;
1326 List<JCVariableDecl> defs = List.nil();
1327 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) {
1328 VarSymbol v = l.head;
1329 VarSymbol proxy = new VarSymbol(
1330 flags, proxyName(v.name), v.erasure(types), owner);
1331 proxies.enter(proxy);
1332 JCVariableDecl vd = make.at(pos).VarDef(proxy, null);
1333 vd.vartype = access(vd.vartype);
1334 defs = defs.prepend(vd);
1335 }
1336 return defs;
1337 }
1338
1339 /** The name of a this$n field
1340 * @param type The class referenced by the this$n field
1341 */
1342 Name outerThisName(Type type, Symbol owner) {
1343 Type t = type.getEnclosingType();
1344 int nestingLevel = 0;
1345 while (t.tag == CLASS) {
1346 t = t.getEnclosingType();
1347 nestingLevel++;
1348 }
1349 Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel);
1350 while (owner.kind == TYP && ((ClassSymbol)owner).members().lookup(result).scope != null)
1351 result = names.fromString(result.toString() + target.syntheticNameChar());
1352 return result;
1353 }
1354
1355 /** Definition for this$n field.
1356 * @param pos The source code position of the definition.
1357 * @param owner The class in which the definition goes.
1358 */
1359 JCVariableDecl outerThisDef(int pos, Symbol owner) {
1360 long flags = FINAL | SYNTHETIC;
1361 if (owner.kind == TYP &&
1362 target.usePrivateSyntheticFields())
1363 flags |= PRIVATE;
1364 Type target = types.erasure(owner.enclClass().type.getEnclosingType());
1365 VarSymbol outerThis = new VarSymbol(
1366 flags, outerThisName(target, owner), target, owner);
1367 outerThisStack = outerThisStack.prepend(outerThis);
1368 JCVariableDecl vd = make.at(pos).VarDef(outerThis, null);
1369 vd.vartype = access(vd.vartype);
1370 return vd;
1371 }
1372
1373 /** Return a list of trees that load the free variables in given list,
1374 * in reverse order.
1375 * @param pos The source code position to be used for the trees.
1376 * @param freevars The list of free variables.
1377 */
1378 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) {
1379 List<JCExpression> args = List.nil();
1380 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail)
1381 args = args.prepend(loadFreevar(pos, l.head));
1382 return args;
1383 }
1384 //where
1385 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) {
1386 return access(v, make.at(pos).Ident(v), null, false);
1387 }
1388
1389 /** Construct a tree simulating the expression <C.this>.
1390 * @param pos The source code position to be used for the tree.
1391 * @param c The qualifier class.
1392 */
1393 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) {
1394 if (currentClass == c) {
1395 // in this case, `this' works fine
1396 return make.at(pos).This(c.erasure(types));
1397 } else {
1398 // need to go via this$n
1399 return makeOuterThis(pos, c);
1400 }
1401 }
1402
1403 /** Construct a tree that represents the outer instance
1404 * <C.this>. Never pick the current `this'.
1405 * @param pos The source code position to be used for the tree.
1406 * @param c The qualifier class.
1407 */
1408 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) {
1409 List<VarSymbol> ots = outerThisStack;
1410 if (ots.isEmpty()) {
1411 log.error(pos, "no.encl.instance.of.type.in.scope", c);
1412 assert false;
1413 return makeNull();
1414 }
1415 VarSymbol ot = ots.head;
1416 JCExpression tree = access(make.at(pos).Ident(ot));
1417 TypeSymbol otc = ot.type.tsym;
1418 while (otc != c) {
1419 do {
1420 ots = ots.tail;
1421 if (ots.isEmpty()) {
1422 log.error(pos,
1423 "no.encl.instance.of.type.in.scope",
1424 c);
1425 assert false; // should have been caught in Attr
1426 return tree;
1427 }
1428 ot = ots.head;
1429 } while (ot.owner != otc);
1430 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) {
1431 chk.earlyRefError(pos, c);
1432 assert false; // should have been caught in Attr
1433 return makeNull();
1434 }
1435 tree = access(make.at(pos).Select(tree, ot));
1436 otc = ot.type.tsym;
1437 }
1438 return tree;
1439 }
1440
1441 /** Construct a tree that represents the closest outer instance
1442 * <C.this> such that the given symbol is a member of C.
1443 * @param pos The source code position to be used for the tree.
1444 * @param sym The accessed symbol.
1445 * @param preciseMatch should we accept a type that is a subtype of
1446 * sym's owner, even if it doesn't contain sym
1447 * due to hiding, overriding, or non-inheritance
1448 * due to protection?
1449 */
1450 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1451 Symbol c = sym.owner;
1452 if (preciseMatch ? sym.isMemberOf(currentClass, types)
1453 : currentClass.isSubClass(sym.owner, types)) {
1454 // in this case, `this' works fine
1455 return make.at(pos).This(c.erasure(types));
1456 } else {
1457 // need to go via this$n
1458 return makeOwnerThisN(pos, sym, preciseMatch);
1459 }
1460 }
1461
1462 /**
1463 * Similar to makeOwnerThis but will never pick "this".
1464 */
1465 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1466 Symbol c = sym.owner;
1467 List<VarSymbol> ots = outerThisStack;
1468 if (ots.isEmpty()) {
1469 log.error(pos, "no.encl.instance.of.type.in.scope", c);
1470 assert false;
1471 return makeNull();
1472 }
1473 VarSymbol ot = ots.head;
1474 JCExpression tree = access(make.at(pos).Ident(ot));
1475 TypeSymbol otc = ot.type.tsym;
1476 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) {
1477 do {
1478 ots = ots.tail;
1479 if (ots.isEmpty()) {
1480 log.error(pos,
1481 "no.encl.instance.of.type.in.scope",
1482 c);
1483 assert false;
1484 return tree;
1485 }
1486 ot = ots.head;
1487 } while (ot.owner != otc);
1488 tree = access(make.at(pos).Select(tree, ot));
1489 otc = ot.type.tsym;
1490 }
1491 return tree;
1492 }
1493
1494 /** Return tree simulating the assignment <this.name = name>, where
1495 * name is the name of a free variable.
1496 */
1497 JCStatement initField(int pos, Name name) {
1498 Scope.Entry e = proxies.lookup(name);
1499 Symbol rhs = e.sym;
1500 assert rhs.owner.kind == MTH;
1501 Symbol lhs = e.next().sym;
1502 assert rhs.owner.owner == lhs.owner;
1503 make.at(pos);
1504 return
1505 make.Exec(
1506 make.Assign(
1507 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1508 make.Ident(rhs)).setType(lhs.erasure(types)));
1509 }
1510
1511 /** Return tree simulating the assignment <this.this$n = this$n>.
1512 */
1513 JCStatement initOuterThis(int pos) {
1514 VarSymbol rhs = outerThisStack.head;
1515 assert rhs.owner.kind == MTH;
1516 VarSymbol lhs = outerThisStack.tail.head;
1517 assert rhs.owner.owner == lhs.owner;
1518 make.at(pos);
1519 return
1520 make.Exec(
1521 make.Assign(
1522 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1523 make.Ident(rhs)).setType(lhs.erasure(types)));
1524 }
1525
1526 /**************************************************************************
1527 * Code for .class
1528 *************************************************************************/
1529
1530 /** Return the symbol of a class to contain a cache of
1531 * compiler-generated statics such as class$ and the
1532 * $assertionsDisabled flag. We create an anonymous nested class
1533 * (unless one already exists) and return its symbol. However,
1534 * for backward compatibility in 1.4 and earlier we use the
1535 * top-level class itself.
1536 */
1537 private ClassSymbol outerCacheClass() {
1538 ClassSymbol clazz = outermostClassDef.sym;
1539 if ((clazz.flags() & INTERFACE) == 0 &&
1540 !target.useInnerCacheClass()) return clazz;
1541 Scope s = clazz.members();
1542 for (Scope.Entry e = s.elems; e != null; e = e.sibling)
1543 if (e.sym.kind == TYP &&
1544 e.sym.name == names.empty &&
1545 (e.sym.flags() & INTERFACE) == 0) return (ClassSymbol) e.sym;
1546 return makeEmptyClass(STATIC | SYNTHETIC, clazz);
1547 }
1548
1549 /** Return symbol for "class$" method. If there is no method definition
1550 * for class$, construct one as follows:
1551 *
1552 * class class$(String x0) {
1553 * try {
1554 * return Class.forName(x0);
1555 * } catch (ClassNotFoundException x1) {
1556 * throw new NoClassDefFoundError(x1.getMessage());
1557 * }
1558 * }
1559 */
1560 private MethodSymbol classDollarSym(DiagnosticPosition pos) {
1561 ClassSymbol outerCacheClass = outerCacheClass();
1562 MethodSymbol classDollarSym =
1563 (MethodSymbol)lookupSynthetic(classDollar,
1564 outerCacheClass.members());
1565 if (classDollarSym == null) {
1566 classDollarSym = new MethodSymbol(
1567 STATIC | SYNTHETIC,
1568 classDollar,
1569 new MethodType(
1570 List.of(syms.stringType),
1571 types.erasure(syms.classType),
1572 List.<Type>nil(),
1573 syms.methodClass),
1574 outerCacheClass);
1575 enterSynthetic(pos, classDollarSym, outerCacheClass.members());
1576
1577 JCMethodDecl md = make.MethodDef(classDollarSym, null);
1578 try {
1579 md.body = classDollarSymBody(pos, md);
1580 } catch (CompletionFailure ex) {
1581 md.body = make.Block(0, List.<JCStatement>nil());
1582 chk.completionError(pos, ex);
1583 }
1584 JCClassDecl outerCacheClassDef = classDef(outerCacheClass);
1585 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(md);
1586 }
1587 return classDollarSym;
1588 }
1589
1590 /** Generate code for class$(String name). */
1591 JCBlock classDollarSymBody(DiagnosticPosition pos, JCMethodDecl md) {
1592 MethodSymbol classDollarSym = md.sym;
1593 ClassSymbol outerCacheClass = (ClassSymbol)classDollarSym.owner;
1594
1595 JCBlock returnResult;
1596
1597 // in 1.4.2 and above, we use
1598 // Class.forName(String name, boolean init, ClassLoader loader);
1599 // which requires we cache the current loader in cl$
1600 if (target.classLiteralsNoInit()) {
1601 // clsym = "private static ClassLoader cl$"
1602 VarSymbol clsym = new VarSymbol(STATIC|SYNTHETIC,
1603 names.fromString("cl" + target.syntheticNameChar()),
1604 syms.classLoaderType,
1605 outerCacheClass);
1606 enterSynthetic(pos, clsym, outerCacheClass.members());
1607
1608 // emit "private static ClassLoader cl$;"
1609 JCVariableDecl cldef = make.VarDef(clsym, null);
1610 JCClassDecl outerCacheClassDef = classDef(outerCacheClass);
1611 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cldef);
1612
1613 // newcache := "new cache$1[0]"
1614 JCNewArray newcache = make.
1615 NewArray(make.Type(outerCacheClass.type),
1616 List.<JCExpression>of(make.Literal(INT, 0).setType(syms.intType)),
1617 null);
1618 newcache.type = new ArrayType(types.erasure(outerCacheClass.type),
1619 syms.arrayClass);
1620
1621 // forNameSym := java.lang.Class.forName(
1622 // String s,boolean init,ClassLoader loader)
1623 Symbol forNameSym = lookupMethod(make_pos, names.forName,
1624 types.erasure(syms.classType),
1625 List.of(syms.stringType,
1626 syms.booleanType,
1627 syms.classLoaderType));
1628 // clvalue := "(cl$ == null) ?
1629 // $newcache.getClass().getComponentType().getClassLoader() : cl$"
1630 JCExpression clvalue =
1631 make.Conditional(
1632 makeBinary(JCTree.EQ, make.Ident(clsym), makeNull()),
1633 make.Assign(
1634 make.Ident(clsym),
1635 makeCall(
1636 makeCall(makeCall(newcache,
1637 names.getClass,
1638 List.<JCExpression>nil()),
1639 names.getComponentType,
1640 List.<JCExpression>nil()),
1641 names.getClassLoader,
1642 List.<JCExpression>nil())).setType(syms.classLoaderType),
1643 make.Ident(clsym)).setType(syms.classLoaderType);
1644
1645 // returnResult := "{ return Class.forName(param1, false, cl$); }"
1646 List<JCExpression> args = List.of(make.Ident(md.params.head.sym),
1647 makeLit(syms.booleanType, 0),
1648 clvalue);
1649 returnResult = make.
1650 Block(0, List.<JCStatement>of(make.
1651 Call(make. // return
1652 App(make.
1653 Ident(forNameSym), args))));
1654 } else {
1655 // forNameSym := java.lang.Class.forName(String s)
1656 Symbol forNameSym = lookupMethod(make_pos,
1657 names.forName,
1658 types.erasure(syms.classType),
1659 List.of(syms.stringType));
1660 // returnResult := "{ return Class.forName(param1); }"
1661 returnResult = make.
1662 Block(0, List.of(make.
1663 Call(make. // return
1664 App(make.
1665 QualIdent(forNameSym),
1666 List.<JCExpression>of(make.
1667 Ident(md.params.
1668 head.sym))))));
1669 }
1670
1671 // catchParam := ClassNotFoundException e1
1672 VarSymbol catchParam =
1673 new VarSymbol(0, make.paramName(1),
1674 syms.classNotFoundExceptionType,
1675 classDollarSym);
1676
1677 JCStatement rethrow;
1678 if (target.hasInitCause()) {
1679 // rethrow = "throw new NoClassDefFoundError().initCause(e);
1680 JCTree throwExpr =
1681 makeCall(makeNewClass(syms.noClassDefFoundErrorType,
1682 List.<JCExpression>nil()),
1683 names.initCause,
1684 List.<JCExpression>of(make.Ident(catchParam)));
1685 rethrow = make.Throw(throwExpr);
1686 } else {
1687 // getMessageSym := ClassNotFoundException.getMessage()
1688 Symbol getMessageSym = lookupMethod(make_pos,
1689 names.getMessage,
1690 syms.classNotFoundExceptionType,
1691 List.<Type>nil());
1692 // rethrow = "throw new NoClassDefFoundError(e.getMessage());"
1693 rethrow = make.
1694 Throw(makeNewClass(syms.noClassDefFoundErrorType,
1695 List.<JCExpression>of(make.App(make.Select(make.Ident(catchParam),
1696 getMessageSym),
1697 List.<JCExpression>nil()))));
1698 }
1699
1700 // rethrowStmt := "( $rethrow )"
1701 JCBlock rethrowStmt = make.Block(0, List.of(rethrow));
1702
1703 // catchBlock := "catch ($catchParam) $rethrowStmt"
1704 JCCatch catchBlock = make.Catch(make.VarDef(catchParam, null),
1705 rethrowStmt);
1706
1707 // tryCatch := "try $returnResult $catchBlock"
1708 JCStatement tryCatch = make.Try(returnResult,
1709 List.of(catchBlock), null);
1710
1711 return make.Block(0, List.of(tryCatch));
1712 }
1713 // where
1714 /** Create an attributed tree of the form left.name(). */
1715 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) {
1716 assert left.type != null;
1717 Symbol funcsym = lookupMethod(make_pos, name, left.type,
1718 TreeInfo.types(args));
1719 return make.App(make.Select(left, funcsym), args);
1720 }
1721
1722 /** The Name Of The variable to cache T.class values.
1723 * @param sig The signature of type T.
1724 */
1725 private Name cacheName(String sig) {
1726 StringBuffer buf = new StringBuffer();
1727 if (sig.startsWith("[")) {
1728 buf = buf.append("array");
1729 while (sig.startsWith("[")) {
1730 buf = buf.append(target.syntheticNameChar());
1731 sig = sig.substring(1);
1732 }
1733 if (sig.startsWith("L")) {
1734 sig = sig.substring(0, sig.length() - 1);
1735 }
1736 } else {
1737 buf = buf.append("class" + target.syntheticNameChar());
1738 }
1739 buf = buf.append(sig.replace('.', target.syntheticNameChar()));
1740 return names.fromString(buf.toString());
1741 }
1742
1743 /** The variable symbol that caches T.class values.
1744 * If none exists yet, create a definition.
1745 * @param sig The signature of type T.
1746 * @param pos The position to report diagnostics, if any.
1747 */
1748 private VarSymbol cacheSym(DiagnosticPosition pos, String sig) {
1749 ClassSymbol outerCacheClass = outerCacheClass();
1750 Name cname = cacheName(sig);
1751 VarSymbol cacheSym =
1752 (VarSymbol)lookupSynthetic(cname, outerCacheClass.members());
1753 if (cacheSym == null) {
1754 cacheSym = new VarSymbol(
1755 STATIC | SYNTHETIC, cname, types.erasure(syms.classType), outerCacheClass);
1756 enterSynthetic(pos, cacheSym, outerCacheClass.members());
1757
1758 JCVariableDecl cacheDef = make.VarDef(cacheSym, null);
1759 JCClassDecl outerCacheClassDef = classDef(outerCacheClass);
1760 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cacheDef);
1761 }
1762 return cacheSym;
1763 }
1764
1765 /** The tree simulating a T.class expression.
1766 * @param clazz The tree identifying type T.
1767 */
1768 private JCExpression classOf(JCTree clazz) {
1769 return classOfType(clazz.type, clazz.pos());
1770 }
1771
1772 private JCExpression classOfType(Type type, DiagnosticPosition pos) {
1773 switch (type.tag) {
1774 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT:
1775 case DOUBLE: case BOOLEAN: case VOID:
1776 // replace with <BoxedClass>.TYPE
1777 ClassSymbol c = types.boxedClass(type);
1778 Symbol typeSym =
1779 rs.access(
1780 rs.findIdentInType(attrEnv, c.type, names.TYPE, VAR),
1781 pos, c.type, names.TYPE, true);
1782 if (typeSym.kind == VAR)
1783 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated
1784 return make.QualIdent(typeSym);
1785 case CLASS: case ARRAY:
1786 if (target.hasClassLiterals()) {
1787 VarSymbol sym = new VarSymbol(
1788 STATIC | PUBLIC | FINAL, names._class,
1789 syms.classType, type.tsym);
1790 return make_at(pos).Select(make.Type(type), sym);
1791 }
1792 // replace with <cache == null ? cache = class$(tsig) : cache>
1793 // where
1794 // - <tsig> is the type signature of T,
1795 // - <cache> is the cache variable for tsig.
1796 String sig =
1797 writer.xClassName(type).toString().replace('/', '.');
1798 Symbol cs = cacheSym(pos, sig);
1799 return make_at(pos).Conditional(
1800 makeBinary(JCTree.EQ, make.Ident(cs), makeNull()),
1801 make.Assign(
1802 make.Ident(cs),
1803 make.App(
1804 make.Ident(classDollarSym(pos)),
1805 List.<JCExpression>of(make.Literal(CLASS, sig)
1806 .setType(syms.stringType))))
1807 .setType(types.erasure(syms.classType)),
1808 make.Ident(cs)).setType(types.erasure(syms.classType));
1809 default:
1810 throw new AssertionError();
1811 }
1812 }
1813
1814 /**************************************************************************
1815 * Code for enabling/disabling assertions.
1816 *************************************************************************/
1817
1818 // This code is not particularly robust if the user has
1819 // previously declared a member named '$assertionsDisabled'.
1820 // The same faulty idiom also appears in the translation of
1821 // class literals above. We should report an error if a
1822 // previous declaration is not synthetic.
1823
1824 private JCExpression assertFlagTest(DiagnosticPosition pos) {
1825 // Outermost class may be either true class or an interface.
1826 ClassSymbol outermostClass = outermostClassDef.sym;
1827
1828 // note that this is a class, as an interface can't contain a statement.
1829 ClassSymbol container = currentClass;
1830
1831 VarSymbol assertDisabledSym =
1832 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled,
1833 container.members());
1834 if (assertDisabledSym == null) {
1835 assertDisabledSym =
1836 new VarSymbol(STATIC | FINAL | SYNTHETIC,
1837 dollarAssertionsDisabled,
1838 syms.booleanType,
1839 container);
1840 enterSynthetic(pos, assertDisabledSym, container.members());
1841 Symbol desiredAssertionStatusSym = lookupMethod(pos,
1842 names.desiredAssertionStatus,
1843 types.erasure(syms.classType),
1844 List.<Type>nil());
1845 JCClassDecl containerDef = classDef(container);
1846 make_at(containerDef.pos());
1847 JCExpression notStatus = makeUnary(JCTree.NOT, make.App(make.Select(
1848 classOfType(types.erasure(outermostClass.type),
1849 containerDef.pos()),
1850 desiredAssertionStatusSym)));
1851 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym,
1852 notStatus);
1853 containerDef.defs = containerDef.defs.prepend(assertDisabledDef);
1854 }
1855 make_at(pos);
1856 return makeUnary(JCTree.NOT, make.Ident(assertDisabledSym));
1857 }
1858
1859
1860 /**************************************************************************
1861 * Building blocks for let expressions
1862 *************************************************************************/
1863
1864 interface TreeBuilder {
1865 JCTree build(JCTree arg);
1866 }
1867
1868 /** Construct an expression using the builder, with the given rval
1869 * expression as an argument to the builder. However, the rval
1870 * expression must be computed only once, even if used multiple
1871 * times in the result of the builder. We do that by
1872 * constructing a "let" expression that saves the rvalue into a
1873 * temporary variable and then uses the temporary variable in
1874 * place of the expression built by the builder. The complete
1875 * resulting expression is of the form
1876 * <pre>
1877 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>;
1878 * in (<b>BUILDER</b>(<b>TEMP</b>)))
1879 * </pre>
1880 * where <code><b>TEMP</b></code> is a newly declared variable
1881 * in the let expression.
1882 */
1883 JCTree abstractRval(JCTree rval, Type type, TreeBuilder builder) {
1884 rval = TreeInfo.skipParens(rval);
1885 switch (rval.getTag()) {
1886 case JCTree.LITERAL:
1887 return builder.build(rval);
1888 case JCTree.IDENT:
1889 JCIdent id = (JCIdent) rval;
1890 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH)
1891 return builder.build(rval);
1892 }
1893 VarSymbol var =
1894 new VarSymbol(FINAL|SYNTHETIC,
1895 names.fromString(
1896 target.syntheticNameChar()
1897 + "" + rval.hashCode()),
1898 type,
1899 currentMethodSym);
1900 rval = convert(rval,type);
1901 JCVariableDecl def = make.VarDef(var, (JCExpression)rval); // XXX cast
1902 JCTree built = builder.build(make.Ident(var));
1903 JCTree res = make.LetExpr(def, built);
1904 res.type = built.type;
1905 return res;
1906 }
1907
1908 // same as above, with the type of the temporary variable computed
1909 JCTree abstractRval(JCTree rval, TreeBuilder builder) {
1910 return abstractRval(rval, rval.type, builder);
1911 }
1912
1913 // same as above, but for an expression that may be used as either
1914 // an rvalue or an lvalue. This requires special handling for
1915 // Select expressions, where we place the left-hand-side of the
1916 // select in a temporary, and for Indexed expressions, where we
1917 // place both the indexed expression and the index value in temps.
1918 JCTree abstractLval(JCTree lval, final TreeBuilder builder) {
1919 lval = TreeInfo.skipParens(lval);
1920 switch (lval.getTag()) {
1921 case JCTree.IDENT:
1922 return builder.build(lval);
1923 case JCTree.SELECT: {
1924 final JCFieldAccess s = (JCFieldAccess)lval;
1925 JCTree selected = TreeInfo.skipParens(s.selected);
1926 Symbol lid = TreeInfo.symbol(s.selected);
1927 if (lid != null && lid.kind == TYP) return builder.build(lval);
1928 return abstractRval(s.selected, new TreeBuilder() {
1929 public JCTree build(final JCTree selected) {
1930 return builder.build(make.Select((JCExpression)selected, s.sym));
1931 }
1932 });
1933 }
1934 case JCTree.INDEXED: {
1935 final JCArrayAccess i = (JCArrayAccess)lval;
1936 return abstractRval(i.indexed, new TreeBuilder() {
1937 public JCTree build(final JCTree indexed) {
1938 return abstractRval(i.index, syms.intType, new TreeBuilder() {
1939 public JCTree build(final JCTree index) {
1940 JCTree newLval = make.Indexed((JCExpression)indexed,
1941 (JCExpression)index);
1942 newLval.setType(i.type);
1943 return builder.build(newLval);
1944 }
1945 });
1946 }
1947 });
1948 }
1949 case JCTree.TYPECAST: {
1950 return abstractLval(((JCTypeCast)lval).expr, builder);
1951 }
1952 }
1953 throw new AssertionError(lval);
1954 }
1955
1956 // evaluate and discard the first expression, then evaluate the second.
1957 JCTree makeComma(final JCTree expr1, final JCTree expr2) {
1958 return abstractRval(expr1, new TreeBuilder() {
1959 public JCTree build(final JCTree discarded) {
1960 return expr2;
1961 }
1962 });
1963 }
1964
1965 /**************************************************************************
1966 * Translation methods
1967 *************************************************************************/
1968
1969 /** Visitor argument: enclosing operator node.
1970 */
1971 private JCExpression enclOp;
1972
1973 /** Visitor method: Translate a single node.
1974 * Attach the source position from the old tree to its replacement tree.
1975 */
1976 public <T extends JCTree> T translate(T tree) {
1977 if (tree == null) {
1978 return null;
1979 } else {
1980 make_at(tree.pos());
1981 T result = super.translate(tree);
1982 if (endPositions != null && result != tree) {
1983 Integer endPos = endPositions.remove(tree);
1984 if (endPos != null) endPositions.put(result, endPos);
1985 }
1986 return result;
1987 }
1988 }
1989
1990 /** Visitor method: Translate a single node, boxing or unboxing if needed.
1991 */
1992 public <T extends JCTree> T translate(T tree, Type type) {
1993 return (tree == null) ? null : boxIfNeeded(translate(tree), type);
1994 }
1995
1996 /** Visitor method: Translate tree.
1997 */
1998 public <T extends JCTree> T translate(T tree, JCExpression enclOp) {
1999 JCExpression prevEnclOp = this.enclOp;
2000 this.enclOp = enclOp;
2001 T res = translate(tree);
2002 this.enclOp = prevEnclOp;
2003 return res;
2004 }
2005
2006 /** Visitor method: Translate list of trees.
2007 */
2008 public <T extends JCTree> List<T> translate(List<T> trees, JCExpression enclOp) {
2009 JCExpression prevEnclOp = this.enclOp;
2010 this.enclOp = enclOp;
2011 List<T> res = translate(trees);
2012 this.enclOp = prevEnclOp;
2013 return res;
2014 }
2015
2016 /** Visitor method: Translate list of trees.
2017 */
2018 public <T extends JCTree> List<T> translate(List<T> trees, Type type) {
2019 if (trees == null) return null;
2020 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
2021 l.head = translate(l.head, type);
2022 return trees;
2023 }
2024
2025 public void visitTopLevel(JCCompilationUnit tree) {
2026 if (tree.packageAnnotations.nonEmpty()) {
2027 Name name = names.package_info;
2028 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2029 if (target.isPackageInfoSynthetic())
2030 // package-info is marked SYNTHETIC in JDK 1.6 and later releases
2031 flags = flags | Flags.SYNTHETIC;
2032 JCClassDecl packageAnnotationsClass
2033 = make.ClassDef(make.Modifiers(flags,
2034 tree.packageAnnotations),
2035 name, List.<JCTypeParameter>nil(),
2036 null, List.<JCExpression>nil(), List.<JCTree>nil());
2037 ClassSymbol c = tree.packge.package_info;
2038 c.flags_field |= flags;
2039 c.attributes_field = tree.packge.attributes_field;
2040 ClassType ctype = (ClassType) c.type;
2041 ctype.supertype_field = syms.objectType;
2042 ctype.interfaces_field = List.nil();
2043 packageAnnotationsClass.sym = c;
2044
2045 translated.append(packageAnnotationsClass);
2046 }
2047 }
2048
2049 public void visitClassDef(JCClassDecl tree) {
2050 ClassSymbol currentClassPrev = currentClass;
2051 MethodSymbol currentMethodSymPrev = currentMethodSym;
2052 currentClass = tree.sym;
2053 currentMethodSym = null;
2054 classdefs.put(currentClass, tree);
2055
2056 proxies = proxies.dup(currentClass);
2057 List<VarSymbol> prevOuterThisStack = outerThisStack;
2058
2059 // If this is an enum definition
2060 if ((tree.mods.flags & ENUM) != 0 &&
2061 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0)
2062 visitEnumDef(tree);
2063
2064 // If this is a nested class, define a this$n field for
2065 // it and add to proxies.
2066 JCVariableDecl otdef = null;
2067 if (currentClass.hasOuterInstance())
2068 otdef = outerThisDef(tree.pos, currentClass);
2069
2070 // If this is a local class, define proxies for all its free variables.
2071 List<JCVariableDecl> fvdefs = freevarDefs(
2072 tree.pos, freevars(currentClass), currentClass);
2073
2074 // Recursively translate superclass, interfaces.
2075 tree.extending = translate(tree.extending);
2076 tree.implementing = translate(tree.implementing);
2077
2078 // Recursively translate members, taking into account that new members
2079 // might be created during the translation and prepended to the member
2080 // list `tree.defs'.
2081 List<JCTree> seen = List.nil();
2082 while (tree.defs != seen) {
2083 List<JCTree> unseen = tree.defs;
2084 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) {
2085 JCTree outermostMemberDefPrev = outermostMemberDef;
2086 if (outermostMemberDefPrev == null) outermostMemberDef = l.head;
2087 l.head = translate(l.head);
2088 outermostMemberDef = outermostMemberDefPrev;
2089 }
2090 seen = unseen;
2091 }
2092
2093 // Convert a protected modifier to public, mask static modifier.
2094 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC;
2095 tree.mods.flags &= ClassFlags;
2096
2097 // Convert name to flat representation, replacing '.' by '$'.
2098 tree.name = Convert.shortName(currentClass.flatName());
2099
2100 // Add this$n and free variables proxy definitions to class.
2101 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) {
2102 tree.defs = tree.defs.prepend(l.head);
2103 enterSynthetic(tree.pos(), l.head.sym, currentClass.members());
2104 }
2105 if (currentClass.hasOuterInstance()) {
2106 tree.defs = tree.defs.prepend(otdef);
2107 enterSynthetic(tree.pos(), otdef.sym, currentClass.members());
2108 }
2109
2110 proxies = proxies.leave();
2111 outerThisStack = prevOuterThisStack;
2112
2113 // Append translated tree to `translated' queue.
2114 translated.append(tree);
2115
2116 currentClass = currentClassPrev;
2117 currentMethodSym = currentMethodSymPrev;
2118
2119 // Return empty block {} as a placeholder for an inner class.
2120 result = make_at(tree.pos()).Block(0, List.<JCStatement>nil());
2121 }
2122
2123 /** Translate an enum class. */
2124 private void visitEnumDef(JCClassDecl tree) {
2125 make_at(tree.pos());
2126
2127 // add the supertype, if needed
2128 if (tree.extending == null)
2129 tree.extending = make.Type(types.supertype(tree.type));
2130
2131 // classOfType adds a cache field to tree.defs unless
2132 // target.hasClassLiterals().
2133 JCExpression e_class = classOfType(tree.sym.type, tree.pos()).
2134 setType(types.erasure(syms.classType));
2135
2136 // process each enumeration constant, adding implicit constructor parameters
2137 int nextOrdinal = 0;
2138 ListBuffer<JCExpression> values = new ListBuffer<JCExpression>();
2139 ListBuffer<JCTree> enumDefs = new ListBuffer<JCTree>();
2140 ListBuffer<JCTree> otherDefs = new ListBuffer<JCTree>();
2141 for (List<JCTree> defs = tree.defs;
2142 defs.nonEmpty();
2143 defs=defs.tail) {
2144 if (defs.head.getTag() == JCTree.VARDEF && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
2145 JCVariableDecl var = (JCVariableDecl)defs.head;
2146 visitEnumConstantDef(var, nextOrdinal++);
2147 values.append(make.QualIdent(var.sym));
2148 enumDefs.append(var);
2149 } else {
2150 otherDefs.append(defs.head);
2151 }
2152 }
2153
2154 // private static final T[] #VALUES = { a, b, c };
2155 Name valuesName = names.fromString(target.syntheticNameChar() + "VALUES");
2156 while (tree.sym.members().lookup(valuesName).scope != null) // avoid name clash
2157 valuesName = names.fromString(valuesName + "" + target.syntheticNameChar());
2158 Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass);
2159 VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC,
2160 valuesName,
2161 arrayType,
2162 tree.type.tsym);
2163 JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)),
2164 List.<JCExpression>nil(),
2165 values.toList());
2166 newArray.type = arrayType;
2167 enumDefs.append(make.VarDef(valuesVar, newArray));
2168 tree.sym.members().enter(valuesVar);
2169
2170 Symbol valuesSym = lookupMethod(tree.pos(), names.values,
2171 tree.type, List.<Type>nil());
2172 List<JCStatement> valuesBody;
2173 if (useClone()) {
2174 // return (T[]) $VALUES.clone();
2175 JCTypeCast valuesResult =
2176 make.TypeCast(valuesSym.type.getReturnType(),
2177 make.App(make.Select(make.Ident(valuesVar),
2178 syms.arrayCloneMethod)));
2179 valuesBody = List.<JCStatement>of(make.Return(valuesResult));
2180 } else {
2181 // template: T[] $result = new T[$values.length];
2182 Name resultName = names.fromString(target.syntheticNameChar() + "result");
2183 while (tree.sym.members().lookup(resultName).scope != null) // avoid name clash
2184 resultName = names.fromString(resultName + "" + target.syntheticNameChar());
2185 VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC,
2186 resultName,
2187 arrayType,
2188 valuesSym);
2189 JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)),
2190 List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)),
2191 null);
2192 resultArray.type = arrayType;
2193 JCVariableDecl decl = make.VarDef(resultVar, resultArray);
2194
2195 // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length);
2196 if (systemArraycopyMethod == null) {
2197 systemArraycopyMethod =
2198 new MethodSymbol(PUBLIC | STATIC,
2199 names.fromString("arraycopy"),
2200 new MethodType(List.<Type>of(syms.objectType,
2201 syms.intType,
2202 syms.objectType,
2203 syms.intType,
2204 syms.intType),
2205 syms.voidType,
2206 List.<Type>nil(),
2207 syms.methodClass),
2208 syms.systemType.tsym);
2209 }
2210 JCStatement copy =
2211 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym),
2212 systemArraycopyMethod),
2213 List.of(make.Ident(valuesVar), make.Literal(0),
2214 make.Ident(resultVar), make.Literal(0),
2215 make.Select(make.Ident(valuesVar), syms.lengthVar))));
2216
2217 // template: return $result;
2218 JCStatement ret = make.Return(make.Ident(resultVar));
2219 valuesBody = List.<JCStatement>of(decl, copy, ret);
2220 }
2221
2222 JCMethodDecl valuesDef =
2223 make.MethodDef((MethodSymbol)valuesSym, make.Block(0, valuesBody));
2224
2225 enumDefs.append(valuesDef);
2226
2227 if (debugLower)
2228 System.err.println(tree.sym + ".valuesDef = " + valuesDef);
2229
2230 /** The template for the following code is:
2231 *
2232 * public static E valueOf(String name) {
2233 * return (E)Enum.valueOf(E.class, name);
2234 * }
2235 *
2236 * where E is tree.sym
2237 */
2238 MethodSymbol valueOfSym = lookupMethod(tree.pos(),
2239 names.valueOf,
2240 tree.sym.type,
2241 List.of(syms.stringType));
2242 assert (valueOfSym.flags() & STATIC) != 0;
2243 VarSymbol nameArgSym = valueOfSym.params.head;
2244 JCIdent nameVal = make.Ident(nameArgSym);
2245 JCStatement enum_ValueOf =
2246 make.Return(make.TypeCast(tree.sym.type,
2247 makeCall(make.Ident(syms.enumSym),
2248 names.valueOf,
2249 List.of(e_class, nameVal))));
2250 JCMethodDecl valueOf = make.MethodDef(valueOfSym,
2251 make.Block(0, List.of(enum_ValueOf)));
2252 nameVal.sym = valueOf.params.head.sym;
2253 if (debugLower)
2254 System.err.println(tree.sym + ".valueOf = " + valueOf);
2255 enumDefs.append(valueOf);
2256
2257 enumDefs.appendList(otherDefs.toList());
2258 tree.defs = enumDefs.toList();
2259
2260 // Add the necessary members for the EnumCompatibleMode
2261 if (target.compilerBootstrap(tree.sym)) {
2262 addEnumCompatibleMembers(tree);
2263 }
2264 }
2265 // where
2266 private MethodSymbol systemArraycopyMethod;
2267 private boolean useClone() {
2268 try {
2269 Scope.Entry e = syms.objectType.tsym.members().lookup(names.clone);
2270 return (e.sym != null);
2271 }
2272 catch (CompletionFailure e) {
2273 return false;
2274 }
2275 }
2276
2277 /** Translate an enumeration constant and its initializer. */
2278 private void visitEnumConstantDef(JCVariableDecl var, int ordinal) {
2279 JCNewClass varDef = (JCNewClass)var.init;
2280 varDef.args = varDef.args.
2281 prepend(makeLit(syms.intType, ordinal)).
2282 prepend(makeLit(syms.stringType, var.name.toString()));
2283 }
2284
2285 public void visitMethodDef(JCMethodDecl tree) {
2286 if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) {
2287 // Add "String $enum$name, int $enum$ordinal" to the beginning of the
2288 // argument list for each constructor of an enum.
2289 JCVariableDecl nameParam = make_at(tree.pos()).
2290 Param(names.fromString(target.syntheticNameChar() +
2291 "enum" + target.syntheticNameChar() + "name"),
2292 syms.stringType, tree.sym);
2293 nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC;
2294
2295 JCVariableDecl ordParam = make.
2296 Param(names.fromString(target.syntheticNameChar() +
2297 "enum" + target.syntheticNameChar() +
2298 "ordinal"),
2299 syms.intType, tree.sym);
2300 ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC;
2301
2302 tree.params = tree.params.prepend(ordParam).prepend(nameParam);
2303
2304 MethodSymbol m = tree.sym;
2305 Type olderasure = m.erasure(types);
2306 m.erasure_field = new MethodType(
2307 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType),
2308 olderasure.getReturnType(),
2309 olderasure.getThrownTypes(),
2310 syms.methodClass);
2311
2312 if (target.compilerBootstrap(m.owner)) {
2313 // Initialize synthetic name field
2314 Symbol nameVarSym = lookupSynthetic(names.fromString("$name"),
2315 tree.sym.owner.members());
2316 JCIdent nameIdent = make.Ident(nameParam.sym);
2317 JCIdent id1 = make.Ident(nameVarSym);
2318 JCAssign newAssign = make.Assign(id1, nameIdent);
2319 newAssign.type = id1.type;
2320 JCExpressionStatement nameAssign = make.Exec(newAssign);
2321 nameAssign.type = id1.type;
2322 tree.body.stats = tree.body.stats.prepend(nameAssign);
2323
2324 // Initialize synthetic ordinal field
2325 Symbol ordinalVarSym = lookupSynthetic(names.fromString("$ordinal"),
2326 tree.sym.owner.members());
2327 JCIdent ordIdent = make.Ident(ordParam.sym);
2328 id1 = make.Ident(ordinalVarSym);
2329 newAssign = make.Assign(id1, ordIdent);
2330 newAssign.type = id1.type;
2331 JCExpressionStatement ordinalAssign = make.Exec(newAssign);
2332 ordinalAssign.type = id1.type;
2333 tree.body.stats = tree.body.stats.prepend(ordinalAssign);
2334 }
2335 }
2336
2337 JCMethodDecl prevMethodDef = currentMethodDef;
2338 MethodSymbol prevMethodSym = currentMethodSym;
2339 try {
2340 currentMethodDef = tree;
2341 currentMethodSym = tree.sym;
2342 visitMethodDefInternal(tree);
2343 } finally {
2344 currentMethodDef = prevMethodDef;
2345 currentMethodSym = prevMethodSym;
2346 }
2347 }
2348 //where
2349 private void visitMethodDefInternal(JCMethodDecl tree) {
2350 if (tree.name == names.init &&
2351 (currentClass.isInner() ||
2352 (currentClass.owner.kind & (VAR | MTH)) != 0)) {
2353 // We are seeing a constructor of an inner class.
2354 MethodSymbol m = tree.sym;
2355
2356 // Push a new proxy scope for constructor parameters.
2357 // and create definitions for any this$n and proxy parameters.
2358 proxies = proxies.dup(m);
2359 List<VarSymbol> prevOuterThisStack = outerThisStack;
2360 List<VarSymbol> fvs = freevars(currentClass);
2361 JCVariableDecl otdef = null;
2362 if (currentClass.hasOuterInstance())
2363 otdef = outerThisDef(tree.pos, m);
2364 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m);
2365
2366 // Recursively translate result type, parameters and thrown list.
2367 tree.restype = translate(tree.restype);
2368 tree.params = translateVarDefs(tree.params);
2369 tree.thrown = translate(tree.thrown);
2370
2371 // when compiling stubs, don't process body
2372 if (tree.body == null) {
2373 result = tree;
2374 return;
2375 }
2376
2377 // Add this$n (if needed) in front of and free variables behind
2378 // constructor parameter list.
2379 tree.params = tree.params.appendList(fvdefs);
2380 if (currentClass.hasOuterInstance())
2381 tree.params = tree.params.prepend(otdef);
2382
2383 // If this is an initial constructor, i.e., it does not start with
2384 // this(...), insert initializers for this$n and proxies
2385 // before (pre-1.4, after) the call to superclass constructor.
2386 JCStatement selfCall = translate(tree.body.stats.head);
2387
2388 List<JCStatement> added = List.nil();
2389 if (fvs.nonEmpty()) {
2390 List<Type> addedargtypes = List.nil();
2391 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
2392 if (TreeInfo.isInitialConstructor(tree))
2393 added = added.prepend(
2394 initField(tree.body.pos, proxyName(l.head.name)));
2395 addedargtypes = addedargtypes.prepend(l.head.erasure(types));
2396 }
2397 Type olderasure = m.erasure(types);
2398 m.erasure_field = new MethodType(
2399 olderasure.getParameterTypes().appendList(addedargtypes),
2400 olderasure.getReturnType(),
2401 olderasure.getThrownTypes(),
2402 syms.methodClass);
2403 }
2404 if (currentClass.hasOuterInstance() &&
2405 TreeInfo.isInitialConstructor(tree))
2406 {
2407 added = added.prepend(initOuterThis(tree.body.pos));
2408 }
2409
2410 // pop local variables from proxy stack
2411 proxies = proxies.leave();
2412
2413 // recursively translate following local statements and
2414 // combine with this- or super-call
2415 List<JCStatement> stats = translate(tree.body.stats.tail);
2416 if (target.initializeFieldsBeforeSuper())
2417 tree.body.stats = stats.prepend(selfCall).prependList(added);
2418 else
2419 tree.body.stats = stats.prependList(added).prepend(selfCall);
2420
2421 outerThisStack = prevOuterThisStack;
2422 } else {
2423 super.visitMethodDef(tree);
2424 }
2425 result = tree;
2426 }
2427
2428 public void visitAnnotatedType(JCAnnotatedType tree) {
2429 tree.underlyingType = translate(tree.underlyingType);
2430 result = tree.underlyingType;
2431 }
2432
2433 public void visitTypeCast(JCTypeCast tree) {
2434 tree.clazz = translate(tree.clazz);
2435 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive())
2436 tree.expr = translate(tree.expr, tree.type);
2437 else
2438 tree.expr = translate(tree.expr);
2439 result = tree;
2440 }
2441
2442 public void visitNewClass(JCNewClass tree) {
2443 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
2444
2445 // Box arguments, if necessary
2446 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0;
2447 List<Type> argTypes = tree.constructor.type.getParameterTypes();
2448 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType);
2449 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement);
2450 tree.varargsElement = null;
2451
2452 // If created class is local, add free variables after
2453 // explicit constructor arguments.
2454 if ((c.owner.kind & (VAR | MTH)) != 0) {
2455 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
2456 }
2457
2458 // If an access constructor is used, append null as a last argument.
2459 Symbol constructor = accessConstructor(tree.pos(), tree.constructor);
2460 if (constructor != tree.constructor) {
2461 tree.args = tree.args.append(makeNull());
2462 tree.constructor = constructor;
2463 }
2464
2465 // If created class has an outer instance, and new is qualified, pass
2466 // qualifier as first argument. If new is not qualified, pass the
2467 // correct outer instance as first argument.
2468 if (c.hasOuterInstance()) {
2469 JCExpression thisArg;
2470 if (tree.encl != null) {
2471 thisArg = attr.makeNullCheck(translate(tree.encl));
2472 thisArg.type = tree.encl.type;
2473 } else if ((c.owner.kind & (MTH | VAR)) != 0) {
2474 // local class
2475 thisArg = makeThis(tree.pos(), c.type.getEnclosingType().tsym);
2476 } else {
2477 // nested class
2478 thisArg = makeOwnerThis(tree.pos(), c, false);
2479 }
2480 tree.args = tree.args.prepend(thisArg);
2481 }
2482 tree.encl = null;
2483
2484 // If we have an anonymous class, create its flat version, rather
2485 // than the class or interface following new.
2486 if (tree.def != null) {
2487 translate(tree.def);
2488 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym));
2489 tree.def = null;
2490 } else {
2491 tree.clazz = access(c, tree.clazz, enclOp, false);
2492 }
2493 result = tree;
2494 }
2495
2496 // Simplify conditionals with known constant controlling expressions.
2497 // This allows us to avoid generating supporting declarations for
2498 // the dead code, which will not be eliminated during code generation.
2499 // Note that Flow.isFalse and Flow.isTrue only return true
2500 // for constant expressions in the sense of JLS 15.27, which
2501 // are guaranteed to have no side-effects. More aggressive
2502 // constant propagation would require that we take care to
2503 // preserve possible side-effects in the condition expression.
2504
2505 /** Visitor method for conditional expressions.
2506 */
2507 public void visitConditional(JCConditional tree) {
2508 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
2509 if (cond.type.isTrue()) {
2510 result = convert(translate(tree.truepart, tree.type), tree.type);
2511 } else if (cond.type.isFalse()) {
2512 result = convert(translate(tree.falsepart, tree.type), tree.type);
2513 } else {
2514 // Condition is not a compile-time constant.
2515 tree.truepart = translate(tree.truepart, tree.type);
2516 tree.falsepart = translate(tree.falsepart, tree.type);
2517 result = tree;
2518 }
2519 }
2520 //where
2521 private JCTree convert(JCTree tree, Type pt) {
2522 if (tree.type == pt) return tree;
2523 JCTree result = make_at(tree.pos()).TypeCast(make.Type(pt), (JCExpression)tree);
2524 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt)
2525 : pt;
2526 return result;
2527 }
2528
2529 /** Visitor method for if statements.
2530 */
2531 public void visitIf(JCIf tree) {
2532 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
2533 if (cond.type.isTrue()) {
2534 result = translate(tree.thenpart);
2535 } else if (cond.type.isFalse()) {
2536 if (tree.elsepart != null) {
2537 result = translate(tree.elsepart);
2538 } else {
2539 result = make.Skip();
2540 }
2541 } else {
2542 // Condition is not a compile-time constant.
2543 tree.thenpart = translate(tree.thenpart);
2544 tree.elsepart = translate(tree.elsepart);
2545 result = tree;
2546 }
2547 }
2548
2549 /** Visitor method for assert statements. Translate them away.
2550 */
2551 public void visitAssert(JCAssert tree) {
2552 DiagnosticPosition detailPos = (tree.detail == null) ? tree.pos() : tree.detail.pos();
2553 tree.cond = translate(tree.cond, syms.booleanType);
2554 if (!tree.cond.type.isTrue()) {
2555 JCExpression cond = assertFlagTest(tree.pos());
2556 List<JCExpression> exnArgs = (tree.detail == null) ?
2557 List.<JCExpression>nil() : List.of(translate(tree.detail));
2558 if (!tree.cond.type.isFalse()) {
2559 cond = makeBinary
2560 (JCTree.AND,
2561 cond,
2562 makeUnary(JCTree.NOT, tree.cond));
2563 }
2564 result =
2565 make.If(cond,
2566 make_at(detailPos).
2567 Throw(makeNewClass(syms.assertionErrorType, exnArgs)),
2568 null);
2569 } else {
2570 result = make.Skip();
2571 }
2572 }
2573
2574 public void visitApply(JCMethodInvocation tree) {
2575 Symbol meth = TreeInfo.symbol(tree.meth);
2576 List<Type> argtypes = meth.type.getParameterTypes();
2577 if (allowEnums &&
2578 meth.name==names.init &&
2579 meth.owner == syms.enumSym)
2580 argtypes = argtypes.tail.tail;
2581 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement);
2582 tree.varargsElement = null;
2583 Name methName = TreeInfo.name(tree.meth);
2584 if (meth.name==names.init) {
2585 // We are seeing a this(...) or super(...) constructor call.
2586 // If an access constructor is used, append null as a last argument.
2587 Symbol constructor = accessConstructor(tree.pos(), meth);
2588 if (constructor != meth) {
2589 tree.args = tree.args.append(makeNull());
2590 TreeInfo.setSymbol(tree.meth, constructor);
2591 }
2592
2593 // If we are calling a constructor of a local class, add
2594 // free variables after explicit constructor arguments.
2595 ClassSymbol c = (ClassSymbol)constructor.owner;
2596 if ((c.owner.kind & (VAR | MTH)) != 0) {
2597 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
2598 }
2599
2600 // If we are calling a constructor of an enum class, pass
2601 // along the name and ordinal arguments
2602 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) {
2603 List<JCVariableDecl> params = currentMethodDef.params;
2604 if (currentMethodSym.owner.hasOuterInstance())
2605 params = params.tail; // drop this$n
2606 tree.args = tree.args
2607 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal
2608 .prepend(make.Ident(params.head.sym)); // name
2609 }
2610
2611 // If we are calling a constructor of a class with an outer
2612 // instance, and the call
2613 // is qualified, pass qualifier as first argument in front of
2614 // the explicit constructor arguments. If the call
2615 // is not qualified, pass the correct outer instance as
2616 // first argument.
2617 if (c.hasOuterInstance()) {
2618 JCExpression thisArg;
2619 if (tree.meth.getTag() == JCTree.SELECT) {
2620 thisArg = attr.
2621 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected));
2622 tree.meth = make.Ident(constructor);
2623 ((JCIdent) tree.meth).name = methName;
2624 } else if ((c.owner.kind & (MTH | VAR)) != 0 || methName == names._this){
2625 // local class or this() call
2626 thisArg = makeThis(tree.meth.pos(), c.type.getEnclosingType().tsym);
2627 } else {
2628 // super() call of nested class
2629 thisArg = makeOwnerThis(tree.meth.pos(), c, false);
2630 }
2631 tree.args = tree.args.prepend(thisArg);
2632 }
2633 } else {
2634 // We are seeing a normal method invocation; translate this as usual.
2635 tree.meth = translate(tree.meth);
2636
2637 // If the translated method itself is an Apply tree, we are
2638 // seeing an access method invocation. In this case, append
2639 // the method arguments to the arguments of the access method.
2640 if (tree.meth.getTag() == JCTree.APPLY) {
2641 JCMethodInvocation app = (JCMethodInvocation)tree.meth;
2642 app.args = tree.args.prependList(app.args);
2643 result = app;
2644 return;
2645 }
2646 }
2647 result = tree;
2648 }
2649
2650 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) {
2651 List<JCExpression> args = _args;
2652 if (parameters.isEmpty()) return args;
2653 boolean anyChanges = false;
2654 ListBuffer<JCExpression> result = new ListBuffer<JCExpression>();
2655 while (parameters.tail.nonEmpty()) {
2656 JCExpression arg = translate(args.head, parameters.head);
2657 anyChanges |= (arg != args.head);
2658 result.append(arg);
2659 args = args.tail;
2660 parameters = parameters.tail;
2661 }
2662 Type parameter = parameters.head;
2663 if (varargsElement != null) {
2664 anyChanges = true;
2665 ListBuffer<JCExpression> elems = new ListBuffer<JCExpression>();
2666 while (args.nonEmpty()) {
2667 JCExpression arg = translate(args.head, varargsElement);
2668 elems.append(arg);
2669 args = args.tail;
2670 }
2671 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement),
2672 List.<JCExpression>nil(),
2673 elems.toList());
2674 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass);
2675 result.append(boxedArgs);
2676 } else {
2677 if (args.length() != 1) throw new AssertionError(args);
2678 JCExpression arg = translate(args.head, parameter);
2679 anyChanges |= (arg != args.head);
2680 result.append(arg);
2681 if (!anyChanges) return _args;
2682 }
2683 return result.toList();
2684 }
2685
2686 /** Expand a boxing or unboxing conversion if needed. */
2687 @SuppressWarnings("unchecked") // XXX unchecked
2688 <T extends JCTree> T boxIfNeeded(T tree, Type type) {
2689 boolean havePrimitive = tree.type.isPrimitive();
2690 if (havePrimitive == type.isPrimitive())
2691 return tree;
2692 if (havePrimitive) {
2693 Type unboxedTarget = types.unboxedType(type);
2694 if (unboxedTarget.tag != NONE) {
2695 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89;
2696 tree.type = unboxedTarget.constType(tree.type.constValue());
2697 return (T)boxPrimitive((JCExpression)tree, type);
2698 } else {
2699 tree = (T)boxPrimitive((JCExpression)tree);
2700 }
2701 } else {
2702 tree = (T)unbox((JCExpression)tree, type);
2703 }
2704 return tree;
2705 }
2706
2707 /** Box up a single primitive expression. */
2708 JCExpression boxPrimitive(JCExpression tree) {
2709 return boxPrimitive(tree, types.boxedClass(tree.type).type);
2710 }
2711
2712 /** Box up a single primitive expression. */
2713 JCExpression boxPrimitive(JCExpression tree, Type box) {
2714 make_at(tree.pos());
2715 if (target.boxWithConstructors()) {
2716 Symbol ctor = lookupConstructor(tree.pos(),
2717 box,
2718 List.<Type>nil()
2719 .prepend(tree.type));
2720 return make.Create(ctor, List.of(tree));
2721 } else {
2722 Symbol valueOfSym = lookupMethod(tree.pos(),
2723 names.valueOf,
2724 box,
2725 List.<Type>nil()
2726 .prepend(tree.type));
2727 return make.App(make.QualIdent(valueOfSym), List.of(tree));
2728 }
2729 }
2730
2731 /** Unbox an object to a primitive value. */
2732 JCExpression unbox(JCExpression tree, Type primitive) {
2733 Type unboxedType = types.unboxedType(tree.type);
2734 // note: the "primitive" parameter is not used. There muse be
2735 // a conversion from unboxedType to primitive.
2736 make_at(tree.pos());
2737 Symbol valueSym = lookupMethod(tree.pos(),
2738 unboxedType.tsym.name.append(names.Value), // x.intValue()
2739 tree.type,
2740 List.<Type>nil());
2741 return make.App(make.Select(tree, valueSym));
2742 }
2743
2744 /** Visitor method for parenthesized expressions.
2745 * If the subexpression has changed, omit the parens.
2746 */
2747 public void visitParens(JCParens tree) {
2748 JCTree expr = translate(tree.expr);
2749 result = ((expr == tree.expr) ? tree : expr);
2750 }
2751
2752 public void visitIndexed(JCArrayAccess tree) {
2753 tree.indexed = translate(tree.indexed);
2754 tree.index = translate(tree.index, syms.intType);
2755 result = tree;
2756 }
2757
2758 public void visitAssign(JCAssign tree) {
2759 tree.lhs = translate(tree.lhs, tree);
2760 tree.rhs = translate(tree.rhs, tree.lhs.type);
2761
2762 // If translated left hand side is an Apply, we are
2763 // seeing an access method invocation. In this case, append
2764 // right hand side as last argument of the access method.
2765 if (tree.lhs.getTag() == JCTree.APPLY) {
2766 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
2767 app.args = List.of(tree.rhs).prependList(app.args);
2768 result = app;
2769 } else {
2770 result = tree;
2771 }
2772 }
2773
2774 public void visitAssignop(final JCAssignOp tree) {
2775 if (!tree.lhs.type.isPrimitive() &&
2776 tree.operator.type.getReturnType().isPrimitive()) {
2777 // boxing required; need to rewrite as x = (unbox typeof x)(x op y);
2778 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y)
2779 // (but without recomputing x)
2780 JCTree newTree = abstractLval(tree.lhs, new TreeBuilder() {
2781 public JCTree build(final JCTree lhs) {
2782 int newTag = tree.getTag() - JCTree.ASGOffset;
2783 // Erasure (TransTypes) can change the type of
2784 // tree.lhs. However, we can still get the
2785 // unerased type of tree.lhs as it is stored
2786 // in tree.type in Attr.
2787 Symbol newOperator = rs.resolveBinaryOperator(tree.pos(),
2788 newTag,
2789 attrEnv,
2790 tree.type,
2791 tree.rhs.type);
2792 JCExpression expr = (JCExpression)lhs;
2793 if (expr.type != tree.type)
2794 expr = make.TypeCast(tree.type, expr);
2795 JCBinary opResult = make.Binary(newTag, expr, tree.rhs);
2796 opResult.operator = newOperator;
2797 opResult.type = newOperator.type.getReturnType();
2798 JCTypeCast newRhs = make.TypeCast(types.unboxedType(tree.type),
2799 opResult);
2800 return make.Assign((JCExpression)lhs, newRhs).setType(tree.type);
2801 }
2802 });
2803 result = translate(newTree);
2804 return;
2805 }
2806 tree.lhs = translate(tree.lhs, tree);
2807 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
2808
2809 // If translated left hand side is an Apply, we are
2810 // seeing an access method invocation. In this case, append
2811 // right hand side as last argument of the access method.
2812 if (tree.lhs.getTag() == JCTree.APPLY) {
2813 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
2814 // if operation is a += on strings,
2815 // make sure to convert argument to string
2816 JCExpression rhs = (((OperatorSymbol)tree.operator).opcode == string_add)
2817 ? makeString(tree.rhs)
2818 : tree.rhs;
2819 app.args = List.of(rhs).prependList(app.args);
2820 result = app;
2821 } else {
2822 result = tree;
2823 }
2824 }
2825
2826 /** Lower a tree of the form e++ or e-- where e is an object type */
2827 JCTree lowerBoxedPostop(final JCUnary tree) {
2828 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2
2829 // or
2830 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2
2831 // where OP is += or -=
2832 final boolean cast = TreeInfo.skipParens(tree.arg).getTag() == JCTree.TYPECAST;
2833 return abstractLval(tree.arg, new TreeBuilder() {
2834 public JCTree build(final JCTree tmp1) {
2835 return abstractRval(tmp1, tree.arg.type, new TreeBuilder() {
2836 public JCTree build(final JCTree tmp2) {
2837 int opcode = (tree.getTag() == JCTree.POSTINC)
2838 ? JCTree.PLUS_ASG : JCTree.MINUS_ASG;
2839 JCTree lhs = cast
2840 ? make.TypeCast(tree.arg.type, (JCExpression)tmp1)
2841 : tmp1;
2842 JCTree update = makeAssignop(opcode,
2843 lhs,
2844 make.Literal(1));
2845 return makeComma(update, tmp2);
2846 }
2847 });
2848 }
2849 });
2850 }
2851
2852 public void visitUnary(JCUnary tree) {
2853 boolean isUpdateOperator =
2854 JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC;
2855 if (isUpdateOperator && !tree.arg.type.isPrimitive()) {
2856 switch(tree.getTag()) {
2857 case JCTree.PREINC: // ++ e
2858 // translate to e += 1
2859 case JCTree.PREDEC: // -- e
2860 // translate to e -= 1
2861 {
2862 int opcode = (tree.getTag() == JCTree.PREINC)
2863 ? JCTree.PLUS_ASG : JCTree.MINUS_ASG;
2864 JCAssignOp newTree = makeAssignop(opcode,
2865 tree.arg,
2866 make.Literal(1));
2867 result = translate(newTree, tree.type);
2868 return;
2869 }
2870 case JCTree.POSTINC: // e ++
2871 case JCTree.POSTDEC: // e --
2872 {
2873 result = translate(lowerBoxedPostop(tree), tree.type);
2874 return;
2875 }
2876 }
2877 throw new AssertionError(tree);
2878 }
2879
2880 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type);
2881
2882 if (tree.getTag() == JCTree.NOT && tree.arg.type.constValue() != null) {
2883 tree.type = cfolder.fold1(bool_not, tree.arg.type);
2884 }
2885
2886 // If translated left hand side is an Apply, we are
2887 // seeing an access method invocation. In this case, return
2888 // that access method invocation as result.
2889 if (isUpdateOperator && tree.arg.getTag() == JCTree.APPLY) {
2890 result = tree.arg;
2891 } else {
2892 result = tree;
2893 }
2894 }
2895
2896 public void visitBinary(JCBinary tree) {
2897 List<Type> formals = tree.operator.type.getParameterTypes();
2898 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head);
2899 switch (tree.getTag()) {
2900 case JCTree.OR:
2901 if (lhs.type.isTrue()) {
2902 result = lhs;
2903 return;
2904 }
2905 if (lhs.type.isFalse()) {
2906 result = translate(tree.rhs, formals.tail.head);
2907 return;
2908 }
2909 break;
2910 case JCTree.AND:
2911 if (lhs.type.isFalse()) {
2912 result = lhs;
2913 return;
2914 }
2915 if (lhs.type.isTrue()) {
2916 result = translate(tree.rhs, formals.tail.head);
2917 return;
2918 }
2919 break;
2920 }
2921 tree.rhs = translate(tree.rhs, formals.tail.head);
2922 result = tree;
2923 }
2924
2925 public void visitIdent(JCIdent tree) {
2926 result = access(tree.sym, tree, enclOp, false);
2927 }
2928
2929 /** Translate away the foreach loop. */
2930 public void visitForeachLoop(JCEnhancedForLoop tree) {
2931 if (types.elemtype(tree.expr.type) == null)
2932 visitIterableForeachLoop(tree);
2933 else
2934 visitArrayForeachLoop(tree);
2935 }
2936 // where
2937 /**
2938 * A statement of the form
2939 *
2940 * <pre>
2941 * for ( T v : arrayexpr ) stmt;
2942 * </pre>
2943 *
2944 * (where arrayexpr is of an array type) gets translated to
2945 *
2946 * <pre>
2947 * for ( { arraytype #arr = arrayexpr;
2948 * int #len = array.length;
2949 * int #i = 0; };
2950 * #i < #len; i$++ ) {
2951 * T v = arr$[#i];
2952 * stmt;
2953 * }
2954 * </pre>
2955 *
2956 * where #arr, #len, and #i are freshly named synthetic local variables.
2957 */
2958 private void visitArrayForeachLoop(JCEnhancedForLoop tree) {
2959 make_at(tree.expr.pos());
2960 VarSymbol arraycache = new VarSymbol(0,
2961 names.fromString("arr" + target.syntheticNameChar()),
2962 tree.expr.type,
2963 currentMethodSym);
2964 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr);
2965 VarSymbol lencache = new VarSymbol(0,
2966 names.fromString("len" + target.syntheticNameChar()),
2967 syms.intType,
2968 currentMethodSym);
2969 JCStatement lencachedef = make.
2970 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar));
2971 VarSymbol index = new VarSymbol(0,
2972 names.fromString("i" + target.syntheticNameChar()),
2973 syms.intType,
2974 currentMethodSym);
2975
2976 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0));
2977 indexdef.init.type = indexdef.type = syms.intType.constType(0);
2978
2979 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef);
2980 JCBinary cond = makeBinary(JCTree.LT, make.Ident(index), make.Ident(lencache));
2981
2982 JCExpressionStatement step = make.Exec(makeUnary(JCTree.PREINC, make.Ident(index)));
2983
2984 Type elemtype = types.elemtype(tree.expr.type);
2985 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache),
2986 make.Ident(index)).setType(elemtype);
2987 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods,
2988 tree.var.name,
2989 tree.var.vartype,
2990 loopvarinit).setType(tree.var.type);
2991 loopvardef.sym = tree.var.sym;
2992 JCBlock body = make.
2993 Block(0, List.of(loopvardef, tree.body));
2994
2995 result = translate(make.
2996 ForLoop(loopinit,
2997 cond,
2998 List.of(step),
2999 body));
3000 patchTargets(body, tree, result);
3001 }
3002 /** Patch up break and continue targets. */
3003 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) {
3004 class Patcher extends TreeScanner {
3005 public void visitBreak(JCBreak tree) {
3006 if (tree.target == src)
3007 tree.target = dest;
3008 }
3009 public void visitContinue(JCContinue tree) {
3010 if (tree.target == src)
3011 tree.target = dest;
3012 }
3013 public void visitClassDef(JCClassDecl tree) {}
3014 }
3015 new Patcher().scan(body);
3016 }
3017 /**
3018 * A statement of the form
3019 *
3020 * <pre>
3021 * for ( T v : coll ) stmt ;
3022 * </pre>
3023 *
3024 * (where coll implements Iterable<? extends T>) gets translated to
3025 *
3026 * <pre>
3027 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) {
3028 * T v = (T) #i.next();
3029 * stmt;
3030 * }
3031 * </pre>
3032 *
3033 * where #i is a freshly named synthetic local variable.
3034 */
3035 private void visitIterableForeachLoop(JCEnhancedForLoop tree) {
3036 make_at(tree.expr.pos());
3037 Type iteratorTarget = syms.objectType;
3038 Type iterableType = types.asSuper(types.upperBound(tree.expr.type),
3039 syms.iterableType.tsym);
3040 if (iterableType.getTypeArguments().nonEmpty())
3041 iteratorTarget = types.erasure(iterableType.getTypeArguments().head);
3042 Type eType = tree.expr.type;
3043 tree.expr.type = types.erasure(eType);
3044 if (eType.tag == TYPEVAR && eType.getUpperBound().isCompound())
3045 tree.expr = make.TypeCast(types.erasure(iterableType), tree.expr);
3046 Symbol iterator = lookupMethod(tree.expr.pos(),
3047 names.iterator,
3048 types.erasure(syms.iterableType),
3049 List.<Type>nil());
3050 VarSymbol itvar = new VarSymbol(0, names.fromString("i" + target.syntheticNameChar()),
3051 types.erasure(iterator.type.getReturnType()),
3052 currentMethodSym);
3053 JCStatement init = make.
3054 VarDef(itvar,
3055 make.App(make.Select(tree.expr, iterator)));
3056 Symbol hasNext = lookupMethod(tree.expr.pos(),
3057 names.hasNext,
3058 itvar.type,
3059 List.<Type>nil());
3060 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext));
3061 Symbol next = lookupMethod(tree.expr.pos(),
3062 names.next,
3063 itvar.type,
3064 List.<Type>nil());
3065 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next));
3066 if (tree.var.type.isPrimitive())
3067 vardefinit = make.TypeCast(types.upperBound(iteratorTarget), vardefinit);
3068 else
3069 vardefinit = make.TypeCast(tree.var.type, vardefinit);
3070 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods,
3071 tree.var.name,
3072 tree.var.vartype,
3073 vardefinit).setType(tree.var.type);
3074 indexDef.sym = tree.var.sym;
3075 JCBlock body = make.Block(0, List.of(indexDef, tree.body));
3076 body.endpos = TreeInfo.endPos(tree.body);
3077 result = translate(make.
3078 ForLoop(List.of(init),
3079 cond,
3080 List.<JCExpressionStatement>nil(),
3081 body));
3082 patchTargets(body, tree, result);
3083 }
3084
3085 public void visitVarDef(JCVariableDecl tree) {
3086 MethodSymbol oldMethodSym = currentMethodSym;
3087 tree.mods = translate(tree.mods);
3088 tree.vartype = translate(tree.vartype);
3089 if (currentMethodSym == null) {
3090 // A class or instance field initializer.
3091 currentMethodSym =
3092 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK,
3093 names.empty, null,
3094 currentClass);
3095 }
3096 if (tree.init != null) tree.init = translate(tree.init, tree.type);
3097 result = tree;
3098 currentMethodSym = oldMethodSym;
3099 }
3100
3101 public void visitBlock(JCBlock tree) {
3102 MethodSymbol oldMethodSym = currentMethodSym;
3103 if (currentMethodSym == null) {
3104 // Block is a static or instance initializer.
3105 currentMethodSym =
3106 new MethodSymbol(tree.flags | BLOCK,
3107 names.empty, null,
3108 currentClass);
3109 }
3110 super.visitBlock(tree);
3111 currentMethodSym = oldMethodSym;
3112 }
3113
3114 public void visitDoLoop(JCDoWhileLoop tree) {
3115 tree.body = translate(tree.body);
3116 tree.cond = translate(tree.cond, syms.booleanType);
3117 result = tree;
3118 }
3119
3120 public void visitWhileLoop(JCWhileLoop tree) {
3121 tree.cond = translate(tree.cond, syms.booleanType);
3122 tree.body = translate(tree.body);
3123 result = tree;
3124 }
3125
3126 public void visitForLoop(JCForLoop tree) {
3127 tree.init = translate(tree.init);
3128 if (tree.cond != null)
3129 tree.cond = translate(tree.cond, syms.booleanType);
3130 tree.step = translate(tree.step);
3131 tree.body = translate(tree.body);
3132 result = tree;
3133 }
3134
3135 public void visitReturn(JCReturn tree) {
3136 if (tree.expr != null)
3137 tree.expr = translate(tree.expr,
3138 types.erasure(currentMethodDef
3139 .restype.type));
3140 result = tree;
3141 }
3142
3143 public void visitSwitch(JCSwitch tree) {
3144 Type selsuper = types.supertype(tree.selector.type);
3145 boolean enumSwitch = selsuper != null &&
3146 (tree.selector.type.tsym.flags() & ENUM) != 0;
3147 boolean stringSwitch = selsuper != null &&
3148 types.isSameType(tree.selector.type, syms.stringType);
3149 Type target = enumSwitch ? tree.selector.type :
3150 (stringSwitch? syms.stringType : syms.intType);
3151 tree.selector = translate(tree.selector, target);
3152 tree.cases = translateCases(tree.cases);
3153 if (enumSwitch) {
3154 result = visitEnumSwitch(tree);
3155 } else if (stringSwitch) {
3156 result = visitStringSwitch(tree);
3157 } else {
3158 result = tree;
3159 }
3160 }
3161
3162 public JCTree visitEnumSwitch(JCSwitch tree) {
3163 TypeSymbol enumSym = tree.selector.type.tsym;
3164 EnumMapping map = mapForEnum(tree.pos(), enumSym);
3165 make_at(tree.pos());
3166 Symbol ordinalMethod = lookupMethod(tree.pos(),
3167 names.ordinal,
3168 tree.selector.type,
3169 List.<Type>nil());
3170 JCArrayAccess selector = make.Indexed(map.mapVar,
3171 make.App(make.Select(tree.selector,
3172 ordinalMethod)));
3173 ListBuffer<JCCase> cases = new ListBuffer<JCCase>();
3174 for (JCCase c : tree.cases) {
3175 if (c.pat != null) {
3176 VarSymbol label = (VarSymbol)TreeInfo.symbol(c.pat);
3177 JCLiteral pat = map.forConstant(label);
3178 cases.append(make.Case(pat, c.stats));
3179 } else {
3180 cases.append(c);
3181 }
3182 }
3183 JCSwitch enumSwitch = make.Switch(selector, cases.toList());
3184 patchTargets(enumSwitch, tree, enumSwitch);
3185 return enumSwitch;
3186 }
3187
3188 public JCTree visitStringSwitch(JCSwitch tree) {
3189 List<JCCase> caseList = tree.getCases();
3190 int alternatives = caseList.size();
3191
3192 if (alternatives == 0) { // Strange but legal possibility
3193 return make.at(tree.pos()).Exec(attr.makeNullCheck(tree.getExpression()));
3194 } else {
3195 /*
3196 * The general approach used is to translate a single
3197 * string switch statement into a series of two chained
3198 * switch statements: the first a synthesized statement
3199 * switching on the argument string's hash value and
3200 * computing a string's position in the list of original
3201 * case labels, if any, followed by a second switch on the
3202 * computed integer value. The second switch has the same
3203 * code structure as the original string switch statement
3204 * except that the string case labels are replaced with
3205 * positional integer constants starting at 0.
3206 *
3207 * The first switch statement can be thought of as an
3208 * inlined map from strings to their position in the case
3209 * label list. An alternate implementation would use an
3210 * actual Map for this purpose, as done for enum switches.
3211 *
3212 * With some additional effort, it would be possible to
3213 * use a single switch statement on the hash code of the
3214 * argument, but care would need to be taken to preserve
3215 * the proper control flow in the presence of hash
3216 * collisions and other complications, such as
3217 * fallthroughs. Switch statements with one or two
3218 * alternatives could also be specially translated into
3219 * if-then statements to omit the computation of the hash
3220 * code.
3221 *
3222 * The generated code assumes that the hashing algorithm
3223 * of String is the same in the compilation environment as
3224 * in the environment the code will run in. The string
3225 * hashing algorithm in the SE JDK has been unchanged
3226 * since at least JDK 1.2. Since the algorithm has been
3227 * specified since that release as well, it is very
3228 * unlikely to be changed in the future.
3229 *
3230 * Different hashing algorithms, such as the length of the
3231 * strings or a perfect hashing algorithm over the
3232 * particular set of case labels, could potentially be
3233 * used instead of String.hashCode.
3234 */
3235
3236 ListBuffer<JCStatement> stmtList = new ListBuffer<JCStatement>();
3237
3238 // Map from String case labels to their original position in
3239 // the list of case labels.
3240 Map<String, Integer> caseLabelToPosition =
3241 new LinkedHashMap<String, Integer>(alternatives + 1, 1.0f);
3242
3243 // Map of hash codes to the string case labels having that hashCode.
3244 Map<Integer, Set<String>> hashToString =
3245 new LinkedHashMap<Integer, Set<String>>(alternatives + 1, 1.0f);
3246
3247 int casePosition = 0;
3248 for(JCCase oneCase : caseList) {
3249 JCExpression expression = oneCase.getExpression();
3250
3251 if (expression != null) { // expression for a "default" case is null
3252 String labelExpr = (String) expression.type.constValue();
3253 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition);
3254 assert mapping == null;
3255 int hashCode = labelExpr.hashCode();
3256
3257 Set<String> stringSet = hashToString.get(hashCode);
3258 if (stringSet == null) {
3259 stringSet = new LinkedHashSet<String>(1, 1.0f);
3260 stringSet.add(labelExpr);
3261 hashToString.put(hashCode, stringSet);
3262 } else {
3263 boolean added = stringSet.add(labelExpr);
3264 assert added;
3265 }
3266 }
3267 casePosition++;
3268 }
3269
3270 // Synthesize a switch statement that has the effect of
3271 // mapping from a string to the integer position of that
3272 // string in the list of case labels. This is done by
3273 // switching on the hashCode of the string followed by an
3274 // if-then-else chain comparing the input for equality
3275 // with all the case labels having that hash value.
3276
3277 /*
3278 * s$ = top of stack;
3279 * tmp$ = -1;
3280 * switch($s.hashCode()) {
3281 * case caseLabel.hashCode:
3282 * if (s$.equals("caseLabel_1")
3283 * tmp$ = caseLabelToPosition("caseLabel_1");
3284 * else if (s$.equals("caseLabel_2"))
3285 * tmp$ = caseLabelToPosition("caseLabel_2");
3286 * ...
3287 * break;
3288 * ...
3289 * }
3290 */
3291
3292 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
3293 names.fromString("s" + tree.pos + target.syntheticNameChar()),
3294 syms.stringType,
3295 currentMethodSym);
3296 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, tree.getExpression()).setType(dollar_s.type));
3297
3298 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC,
3299 names.fromString("tmp" + tree.pos + target.syntheticNameChar()),
3300 syms.intType,
3301 currentMethodSym);
3302 JCVariableDecl dollar_tmp_def =
3303 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type);
3304 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType;
3305 stmtList.append(dollar_tmp_def);
3306 ListBuffer<JCCase> caseBuffer = ListBuffer.lb();
3307 // hashCode will trigger nullcheck on original switch expression
3308 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s),
3309 names.hashCode,
3310 List.<JCExpression>nil()).setType(syms.intType);
3311 JCSwitch switch1 = make.Switch(hashCodeCall,
3312 caseBuffer.toList());
3313 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) {
3314 int hashCode = entry.getKey();
3315 Set<String> stringsWithHashCode = entry.getValue();
3316 assert stringsWithHashCode.size() >= 1;
3317
3318 JCStatement elsepart = null;
3319 for(String caseLabel : stringsWithHashCode ) {
3320 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s),
3321 names.equals,
3322 List.<JCExpression>of(make.Literal(caseLabel)));
3323 elsepart = make.If(stringEqualsCall,
3324 make.Exec(make.Assign(make.Ident(dollar_tmp),
3325 make.Literal(caseLabelToPosition.get(caseLabel))).
3326 setType(dollar_tmp.type)),
3327 elsepart);
3328 }
3329
3330 ListBuffer<JCStatement> lb = ListBuffer.lb();
3331 JCBreak breakStmt = make.Break(null);
3332 breakStmt.target = switch1;
3333 lb.append(elsepart).append(breakStmt);
3334
3335 caseBuffer.append(make.Case(make.Literal(hashCode), lb.toList()));
3336 }
3337
3338 switch1.cases = caseBuffer.toList();
3339 stmtList.append(switch1);
3340
3341 // Make isomorphic switch tree replacing string labels
3342 // with corresponding integer ones from the label to
3343 // position map.
3344
3345 ListBuffer<JCCase> lb = ListBuffer.lb();
3346 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList());
3347 for(JCCase oneCase : caseList ) {
3348 // Rewire up old unlabeled break statements to the
3349 // replacement switch being created.
3350 patchTargets(oneCase, tree, switch2);
3351
3352 boolean isDefault = (oneCase.getExpression() == null);
3353 JCExpression caseExpr;
3354 if (isDefault)
3355 caseExpr = null;
3356 else {
3357 caseExpr = make.Literal(caseLabelToPosition.get((String)oneCase.
3358 getExpression().
3359 type.constValue()));
3360 }
3361
3362 lb.append(make.Case(caseExpr,
3363 oneCase.getStatements()));
3364 }
3365
3366 switch2.cases = lb.toList();
3367 stmtList.append(switch2);
3368
3369 return make.Block(0L, stmtList.toList());
3370 }
3371 }
3372
3373 public void visitNewArray(JCNewArray tree) {
3374 tree.elemtype = translate(tree.elemtype);
3375 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail)
3376 if (t.head != null) t.head = translate(t.head, syms.intType);
3377 tree.elems = translate(tree.elems, types.elemtype(tree.type));
3378 result = tree;
3379 }
3380
3381 public void visitSelect(JCFieldAccess tree) {
3382 // need to special case-access of the form C.super.x
3383 // these will always need an access method.
3384 boolean qualifiedSuperAccess =
3385 tree.selected.getTag() == JCTree.SELECT &&
3386 TreeInfo.name(tree.selected) == names._super;
3387 tree.selected = translate(tree.selected);
3388 if (tree.name == names._class)
3389 result = classOf(tree.selected);
3390 else if (tree.name == names._this || tree.name == names._super)
3391 result = makeThis(tree.pos(), tree.selected.type.tsym);
3392 else
3393 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess);
3394 }
3395
3396 public void visitLetExpr(LetExpr tree) {
3397 tree.defs = translateVarDefs(tree.defs);
3398 tree.expr = translate(tree.expr, tree.type);
3399 result = tree;
3400 }
3401
3402 // There ought to be nothing to rewrite here;
3403 // we don't generate code.
3404 public void visitAnnotation(JCAnnotation tree) {
3405 result = tree;
3406 }
3407
3408 /**************************************************************************
3409 * main method
3410 *************************************************************************/
3411
3412 /** Translate a toplevel class and return a list consisting of
3413 * the translated class and translated versions of all inner classes.
3414 * @param env The attribution environment current at the class definition.
3415 * We need this for resolving some additional symbols.
3416 * @param cdef The tree representing the class definition.
3417 */
3418 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) {
3419 ListBuffer<JCTree> translated = null;
3420 try {
3421 attrEnv = env;
3422 this.make = make;
3423 endPositions = env.toplevel.endPositions;
3424 currentClass = null;
3425 currentMethodDef = null;
3426 outermostClassDef = (cdef.getTag() == JCTree.CLASSDEF) ? (JCClassDecl)cdef : null;
3427 outermostMemberDef = null;
3428 this.translated = new ListBuffer<JCTree>();
3429 classdefs = new HashMap<ClassSymbol,JCClassDecl>();
3430 actualSymbols = new HashMap<Symbol,Symbol>();
3431 freevarCache = new HashMap<ClassSymbol,List<VarSymbol>>();
3432 proxies = new Scope(syms.noSymbol);
3433 outerThisStack = List.nil();
3434 accessNums = new HashMap<Symbol,Integer>();
3435 accessSyms = new HashMap<Symbol,MethodSymbol[]>();
3436 accessConstrs = new HashMap<Symbol,MethodSymbol>();
3437 accessConstrTags = List.nil();
3438 accessed = new ListBuffer<Symbol>();
3439 translate(cdef, (JCExpression)null);
3440 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail)
3441 makeAccessible(l.head);
3442 for (EnumMapping map : enumSwitchMap.values())
3443 map.translate();
3444 checkConflicts(this.translated.toList());
3445 checkAccessConstructorTags();
3446 translated = this.translated;
3447 } finally {
3448 // note that recursive invocations of this method fail hard
3449 attrEnv = null;
3450 this.make = null;
3451 endPositions = null;
3452 currentClass = null;
3453 currentMethodDef = null;
3454 outermostClassDef = null;
3455 outermostMemberDef = null;
3456 this.translated = null;
3457 classdefs = null;
3458 actualSymbols = null;
3459 freevarCache = null;
3460 proxies = null;
3461 outerThisStack = null;
3462 accessNums = null;
3463 accessSyms = null;
3464 accessConstrs = null;
3465 accessConstrTags = null;
3466 accessed = null;
3467 enumSwitchMap.clear();
3468 }
3469 return translated.toList();
3470 }
3471
3472 //////////////////////////////////////////////////////////////
3473 // The following contributed by Borland for bootstrapping purposes
3474 //////////////////////////////////////////////////////////////
3475 private void addEnumCompatibleMembers(JCClassDecl cdef) {
3476 make_at(null);
3477
3478 // Add the special enum fields
3479 VarSymbol ordinalFieldSym = addEnumOrdinalField(cdef);
3480 VarSymbol nameFieldSym = addEnumNameField(cdef);
3481
3482 // Add the accessor methods for name and ordinal
3483 MethodSymbol ordinalMethodSym = addEnumFieldOrdinalMethod(cdef, ordinalFieldSym);
3484 MethodSymbol nameMethodSym = addEnumFieldNameMethod(cdef, nameFieldSym);
3485
3486 // Add the toString method
3487 addEnumToString(cdef, nameFieldSym);
3488
3489 // Add the compareTo method
3490 addEnumCompareTo(cdef, ordinalFieldSym);
3491 }
3492
3493 private VarSymbol addEnumOrdinalField(JCClassDecl cdef) {
3494 VarSymbol ordinal = new VarSymbol(PRIVATE|FINAL|SYNTHETIC,
3495 names.fromString("$ordinal"),
3496 syms.intType,
3497 cdef.sym);
3498 cdef.sym.members().enter(ordinal);
3499 cdef.defs = cdef.defs.prepend(make.VarDef(ordinal, null));
3500 return ordinal;
3501 }
3502
3503 private VarSymbol addEnumNameField(JCClassDecl cdef) {
3504 VarSymbol name = new VarSymbol(PRIVATE|FINAL|SYNTHETIC,
3505 names.fromString("$name"),
3506 syms.stringType,
3507 cdef.sym);
3508 cdef.sym.members().enter(name);
3509 cdef.defs = cdef.defs.prepend(make.VarDef(name, null));
3510 return name;
3511 }
3512
3513 private MethodSymbol addEnumFieldOrdinalMethod(JCClassDecl cdef, VarSymbol ordinalSymbol) {
3514 // Add the accessor methods for ordinal
3515 Symbol ordinalSym = lookupMethod(cdef.pos(),
3516 names.ordinal,
3517 cdef.type,
3518 List.<Type>nil());
3519
3520 assert(ordinalSym != null);
3521 assert(ordinalSym instanceof MethodSymbol);
3522
3523 JCStatement ret = make.Return(make.Ident(ordinalSymbol));
3524 cdef.defs = cdef.defs.append(make.MethodDef((MethodSymbol)ordinalSym,
3525 make.Block(0L, List.of(ret))));
3526
3527 return (MethodSymbol)ordinalSym;
3528 }
3529
3530 private MethodSymbol addEnumFieldNameMethod(JCClassDecl cdef, VarSymbol nameSymbol) {
3531 // Add the accessor methods for name
3532 Symbol nameSym = lookupMethod(cdef.pos(),
3533 names._name,
3534 cdef.type,
3535 List.<Type>nil());
3536
3537 assert(nameSym != null);
3538 assert(nameSym instanceof MethodSymbol);
3539
3540 JCStatement ret = make.Return(make.Ident(nameSymbol));
3541
3542 cdef.defs = cdef.defs.append(make.MethodDef((MethodSymbol)nameSym,
3543 make.Block(0L, List.of(ret))));
3544
3545 return (MethodSymbol)nameSym;
3546 }
3547
3548 private MethodSymbol addEnumToString(JCClassDecl cdef,
3549 VarSymbol nameSymbol) {
3550 Symbol toStringSym = lookupMethod(cdef.pos(),
3551 names.toString,
3552 cdef.type,
3553 List.<Type>nil());
3554
3555 JCTree toStringDecl = null;
3556 if (toStringSym != null)
3557 toStringDecl = TreeInfo.declarationFor(toStringSym, cdef);
3558
3559 if (toStringDecl != null)
3560 return (MethodSymbol)toStringSym;
3561
3562 JCStatement ret = make.Return(make.Ident(nameSymbol));
3563
3564 JCTree resTypeTree = make.Type(syms.stringType);
3565
3566 MethodType toStringType = new MethodType(List.<Type>nil(),
3567 syms.stringType,
3568 List.<Type>nil(),
3569 cdef.sym);
3570 toStringSym = new MethodSymbol(PUBLIC,
3571 names.toString,
3572 toStringType,
3573 cdef.type.tsym);
3574 toStringDecl = make.MethodDef((MethodSymbol)toStringSym,
3575 make.Block(0L, List.of(ret)));
3576
3577 cdef.defs = cdef.defs.prepend(toStringDecl);
3578 cdef.sym.members().enter(toStringSym);
3579
3580 return (MethodSymbol)toStringSym;
3581 }
3582
3583 private MethodSymbol addEnumCompareTo(JCClassDecl cdef, VarSymbol ordinalSymbol) {
3584 Symbol compareToSym = lookupMethod(cdef.pos(),
3585 names.compareTo,
3586 cdef.type,
3587 List.of(cdef.sym.type));
3588
3589 assert(compareToSym != null);
3590 assert(compareToSym instanceof MethodSymbol);
3591
3592 JCMethodDecl compareToDecl = (JCMethodDecl) TreeInfo.declarationFor(compareToSym, cdef);
3593
3594 ListBuffer<JCStatement> blockStatements = new ListBuffer<JCStatement>();
3595
3596 JCModifiers mod1 = make.Modifiers(0L);
3597 Name oName = names.fromString("o");
3598 JCVariableDecl par1 = make.Param(oName, cdef.type, compareToSym);
3599
3600 JCIdent paramId1 = make.Ident(names.java_lang_Object);
3601 paramId1.type = cdef.type;
3602 paramId1.sym = par1.sym;
3603
3604 ((MethodSymbol)compareToSym).params = List.of(par1.sym);
3605
3606 JCIdent par1UsageId = make.Ident(par1.sym);
3607 JCIdent castTargetIdent = make.Ident(cdef.sym);
3608 JCTypeCast cast = make.TypeCast(castTargetIdent, par1UsageId);
3609 cast.setType(castTargetIdent.type);
3610
3611 Name otherName = names.fromString("other");
3612
3613 VarSymbol otherVarSym = new VarSymbol(mod1.flags,
3614 otherName,
3615 cdef.type,
3616 compareToSym);
3617 JCVariableDecl otherVar = make.VarDef(otherVarSym, cast);
3618 blockStatements.append(otherVar);
3619
3620 JCIdent id1 = make.Ident(ordinalSymbol);
3621
3622 JCIdent fLocUsageId = make.Ident(otherVarSym);
3623 JCExpression sel = make.Select(fLocUsageId, ordinalSymbol);
3624 JCBinary bin = makeBinary(JCTree.MINUS, id1, sel);
3625 JCReturn ret = make.Return(bin);
3626 blockStatements.append(ret);
3627 JCMethodDecl compareToMethod = make.MethodDef((MethodSymbol)compareToSym,
3628 make.Block(0L,
3629 blockStatements.toList()));
3630 compareToMethod.params = List.of(par1);
3631 cdef.defs = cdef.defs.append(compareToMethod);
3632
3633 return (MethodSymbol)compareToSym;
3634 }
3635 //////////////////////////////////////////////////////////////
3636 // The above contributed by Borland for bootstrapping purposes
3637 //////////////////////////////////////////////////////////////
3638 }