1 /*
2 * Copyright (c) 1999, 2016, 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.code.Kinds.KindSelector;
32 import com.sun.tools.javac.code.Scope.WriteableScope;
33 import com.sun.tools.javac.jvm.*;
34 import com.sun.tools.javac.main.Option.PkgInfo;
35 import com.sun.tools.javac.tree.*;
36 import com.sun.tools.javac.util.*;
37 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
38 import com.sun.tools.javac.util.List;
39
40 import com.sun.tools.javac.code.Symbol.*;
41 import com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode;
42 import com.sun.tools.javac.tree.JCTree.*;
43 import com.sun.tools.javac.code.Type.*;
44
45 import com.sun.tools.javac.jvm.Target;
46 import com.sun.tools.javac.tree.EndPosTable;
47
48 import static com.sun.tools.javac.code.Flags.*;
49 import static com.sun.tools.javac.code.Flags.BLOCK;
50 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
51 import static com.sun.tools.javac.code.TypeTag.*;
52 import static com.sun.tools.javac.code.Kinds.Kind.*;
53 import static com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode.DEREF;
54 import static com.sun.tools.javac.jvm.ByteCodes.*;
55 import static com.sun.tools.javac.tree.JCTree.JCOperatorExpression.OperandPos.LEFT;
56 import static com.sun.tools.javac.tree.JCTree.Tag.*;
57
58 /** This pass translates away some syntactic sugar: inner classes,
59 * class literals, assertions, foreach loops, etc.
60 *
61 * <p><b>This is NOT part of any supported API.
62 * If you write code that depends on this, you do so at your own risk.
63 * This code and its internal interfaces are subject to change or
64 * deletion without notice.</b>
65 */
66 public class Lower extends TreeTranslator {
67 protected static final Context.Key<Lower> lowerKey = new Context.Key<>();
68
69 public static Lower instance(Context context) {
70 Lower instance = context.get(lowerKey);
71 if (instance == null)
72 instance = new Lower(context);
73 return instance;
74 }
75
76 private final Names names;
77 private final Log log;
78 private final Symtab syms;
79 private final Resolve rs;
80 private final Operators operators;
81 private final Check chk;
82 private final Attr attr;
83 private TreeMaker make;
84 private DiagnosticPosition make_pos;
85 private final ClassWriter writer;
86 private final ConstFold cfolder;
87 private final Target target;
88 private final Source source;
89 private final TypeEnvs typeEnvs;
90 private final Name dollarAssertionsDisabled;
91 private final Name classDollar;
92 private final Name dollarCloseResource;
93 private final Types types;
94 private final boolean debugLower;
95 private final PkgInfo pkginfoOpt;
96
97 protected Lower(Context context) {
98 context.put(lowerKey, this);
99 names = Names.instance(context);
100 log = Log.instance(context);
101 syms = Symtab.instance(context);
102 rs = Resolve.instance(context);
103 operators = Operators.instance(context);
104 chk = Check.instance(context);
105 attr = Attr.instance(context);
106 make = TreeMaker.instance(context);
107 writer = ClassWriter.instance(context);
108 cfolder = ConstFold.instance(context);
109 target = Target.instance(context);
110 source = Source.instance(context);
111 typeEnvs = TypeEnvs.instance(context);
112 dollarAssertionsDisabled = names.
113 fromString(target.syntheticNameChar() + "assertionsDisabled");
114 classDollar = names.
115 fromString("class" + target.syntheticNameChar());
116 dollarCloseResource = names.
117 fromString(target.syntheticNameChar() + "closeResource");
118
119 types = Types.instance(context);
120 Options options = Options.instance(context);
121 debugLower = options.isSet("debuglower");
122 pkginfoOpt = PkgInfo.get(options);
123 }
124
125 /** The currently enclosing class.
126 */
127 ClassSymbol currentClass;
128
129 /** A queue of all translated classes.
130 */
131 ListBuffer<JCTree> translated;
132
133 /** Environment for symbol lookup, set by translateTopLevelClass.
134 */
135 Env<AttrContext> attrEnv;
136
137 /** A hash table mapping syntax trees to their ending source positions.
138 */
139 EndPosTable endPosTable;
140
141 /**************************************************************************
142 * Global mappings
143 *************************************************************************/
144
145 /** A hash table mapping local classes to their definitions.
146 */
147 Map<ClassSymbol, JCClassDecl> classdefs;
148
149 /** A hash table mapping local classes to a list of pruned trees.
150 */
151 public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<>();
152
153 /** A hash table mapping virtual accessed symbols in outer subclasses
154 * to the actually referred symbol in superclasses.
155 */
156 Map<Symbol,Symbol> actualSymbols;
157
158 /** The current method definition.
159 */
160 JCMethodDecl currentMethodDef;
161
162 /** The current method symbol.
163 */
164 MethodSymbol currentMethodSym;
165
166 /** The currently enclosing outermost class definition.
167 */
168 JCClassDecl outermostClassDef;
169
170 /** The currently enclosing outermost member definition.
171 */
172 JCTree outermostMemberDef;
173
174 /** A map from local variable symbols to their translation (as per LambdaToMethod).
175 * This is required when a capturing local class is created from a lambda (in which
176 * case the captured symbols should be replaced with the translated lambda symbols).
177 */
178 Map<Symbol, Symbol> lambdaTranslationMap = null;
179
180 /** A navigator class for assembling a mapping from local class symbols
181 * to class definition trees.
182 * There is only one case; all other cases simply traverse down the tree.
183 */
184 class ClassMap extends TreeScanner {
185
186 /** All encountered class defs are entered into classdefs table.
187 */
188 public void visitClassDef(JCClassDecl tree) {
189 classdefs.put(tree.sym, tree);
190 super.visitClassDef(tree);
191 }
192 }
193 ClassMap classMap = new ClassMap();
194
195 /** Map a class symbol to its definition.
196 * @param c The class symbol of which we want to determine the definition.
197 */
198 JCClassDecl classDef(ClassSymbol c) {
199 // First lookup the class in the classdefs table.
200 JCClassDecl def = classdefs.get(c);
201 if (def == null && outermostMemberDef != null) {
202 // If this fails, traverse outermost member definition, entering all
203 // local classes into classdefs, and try again.
204 classMap.scan(outermostMemberDef);
205 def = classdefs.get(c);
206 }
207 if (def == null) {
208 // If this fails, traverse outermost class definition, entering all
209 // local classes into classdefs, and try again.
210 classMap.scan(outermostClassDef);
211 def = classdefs.get(c);
212 }
213 return def;
214 }
215
216 /** A hash table mapping class symbols to lists of free variables.
217 * accessed by them. Only free variables of the method immediately containing
218 * a class are associated with that class.
219 */
220 Map<ClassSymbol,List<VarSymbol>> freevarCache;
221
222 /** A navigator class for collecting the free variables accessed
223 * from a local class. There is only one case; all other cases simply
224 * traverse down the tree. This class doesn't deal with the specific
225 * of Lower - it's an abstract visitor that is meant to be reused in
226 * order to share the local variable capture logic.
227 */
228 abstract class BasicFreeVarCollector extends TreeScanner {
229
230 /** Add all free variables of class c to fvs list
231 * unless they are already there.
232 */
233 abstract void addFreeVars(ClassSymbol c);
234
235 /** If tree refers to a variable in owner of local class, add it to
236 * free variables list.
237 */
238 public void visitIdent(JCIdent tree) {
239 visitSymbol(tree.sym);
240 }
241 // where
242 abstract void visitSymbol(Symbol _sym);
243
244 /** If tree refers to a class instance creation expression
245 * add all free variables of the freshly created class.
246 */
247 public void visitNewClass(JCNewClass tree) {
248 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
249 addFreeVars(c);
250 super.visitNewClass(tree);
251 }
252
253 /** If tree refers to a superclass constructor call,
254 * add all free variables of the superclass.
255 */
256 public void visitApply(JCMethodInvocation tree) {
257 if (TreeInfo.name(tree.meth) == names._super) {
258 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner);
259 }
260 super.visitApply(tree);
261 }
262 }
263
264 /**
265 * Lower-specific subclass of {@code BasicFreeVarCollector}.
266 */
267 class FreeVarCollector extends BasicFreeVarCollector {
268
269 /** The owner of the local class.
270 */
271 Symbol owner;
272
273 /** The local class.
274 */
275 ClassSymbol clazz;
276
277 /** The list of owner's variables accessed from within the local class,
278 * without any duplicates.
279 */
280 List<VarSymbol> fvs;
281
282 FreeVarCollector(ClassSymbol clazz) {
283 this.clazz = clazz;
284 this.owner = clazz.owner;
285 this.fvs = List.nil();
286 }
287
288 /** Add free variable to fvs list unless it is already there.
289 */
290 private void addFreeVar(VarSymbol v) {
291 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail)
292 if (l.head == v) return;
293 fvs = fvs.prepend(v);
294 }
295
296 @Override
297 void addFreeVars(ClassSymbol c) {
298 List<VarSymbol> fvs = freevarCache.get(c);
299 if (fvs != null) {
300 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
301 addFreeVar(l.head);
302 }
303 }
304 }
305
306 @Override
307 void visitSymbol(Symbol _sym) {
308 Symbol sym = _sym;
309 if (sym.kind == VAR || sym.kind == MTH) {
310 while (sym != null && sym.owner != owner)
311 sym = proxies.findFirst(proxyName(sym.name));
312 if (sym != null && sym.owner == owner) {
313 VarSymbol v = (VarSymbol)sym;
314 if (v.getConstValue() == null) {
315 addFreeVar(v);
316 }
317 } else {
318 if (outerThisStack.head != null &&
319 outerThisStack.head != _sym)
320 visitSymbol(outerThisStack.head);
321 }
322 }
323 }
324
325 /** If tree refers to a class instance creation expression
326 * add all free variables of the freshly created class.
327 */
328 public void visitNewClass(JCNewClass tree) {
329 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
330 if (tree.encl == null &&
331 c.hasOuterInstance() &&
332 outerThisStack.head != null)
333 visitSymbol(outerThisStack.head);
334 super.visitNewClass(tree);
335 }
336
337 /** If tree refers to a qualified this or super expression
338 * for anything but the current class, add the outer this
339 * stack as a free variable.
340 */
341 public void visitSelect(JCFieldAccess tree) {
342 if ((tree.name == names._this || tree.name == names._super) &&
343 tree.selected.type.tsym != clazz &&
344 outerThisStack.head != null)
345 visitSymbol(outerThisStack.head);
346 super.visitSelect(tree);
347 }
348
349 /** If tree refers to a superclass constructor call,
350 * add all free variables of the superclass.
351 */
352 public void visitApply(JCMethodInvocation tree) {
353 if (TreeInfo.name(tree.meth) == names._super) {
354 Symbol constructor = TreeInfo.symbol(tree.meth);
355 ClassSymbol c = (ClassSymbol)constructor.owner;
356 if (c.hasOuterInstance() &&
357 !tree.meth.hasTag(SELECT) &&
358 outerThisStack.head != null)
359 visitSymbol(outerThisStack.head);
360 }
361 super.visitApply(tree);
362 }
363 }
364
365 ClassSymbol ownerToCopyFreeVarsFrom(ClassSymbol c) {
366 if (!c.isLocal()) {
367 return null;
368 }
369 Symbol currentOwner = c.owner;
370 while (currentOwner.owner.kind.matches(KindSelector.TYP) && currentOwner.isLocal()) {
371 currentOwner = currentOwner.owner;
372 }
373 if (currentOwner.owner.kind.matches(KindSelector.VAL_MTH) && c.isSubClass(currentOwner, types)) {
374 return (ClassSymbol)currentOwner;
375 }
376 return null;
377 }
378
379 /** Return the variables accessed from within a local class, which
380 * are declared in the local class' owner.
381 * (in reverse order of first access).
382 */
383 List<VarSymbol> freevars(ClassSymbol c) {
384 List<VarSymbol> fvs = freevarCache.get(c);
385 if (fvs != null) {
386 return fvs;
387 }
388 if (c.owner.kind.matches(KindSelector.VAL_MTH)) {
389 FreeVarCollector collector = new FreeVarCollector(c);
390 collector.scan(classDef(c));
391 fvs = collector.fvs;
392 freevarCache.put(c, fvs);
393 return fvs;
394 } else {
395 ClassSymbol owner = ownerToCopyFreeVarsFrom(c);
396 if (owner != null) {
397 fvs = freevarCache.get(owner);
398 freevarCache.put(c, fvs);
399 return fvs;
400 } else {
401 return List.nil();
402 }
403 }
404 }
405
406 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>();
407
408 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) {
409 EnumMapping map = enumSwitchMap.get(enumClass);
410 if (map == null)
411 enumSwitchMap.put(enumClass, map = new EnumMapping(pos, enumClass));
412 return map;
413 }
414
415 /** This map gives a translation table to be used for enum
416 * switches.
417 *
418 * <p>For each enum that appears as the type of a switch
419 * expression, we maintain an EnumMapping to assist in the
420 * translation, as exemplified by the following example:
421 *
422 * <p>we translate
423 * <pre>
424 * switch(colorExpression) {
425 * case red: stmt1;
426 * case green: stmt2;
427 * }
428 * </pre>
429 * into
430 * <pre>
431 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) {
432 * case 1: stmt1;
433 * case 2: stmt2
434 * }
435 * </pre>
436 * with the auxiliary table initialized as follows:
437 * <pre>
438 * class Outer$0 {
439 * synthetic final int[] $EnumMap$Color = new int[Color.values().length];
440 * static {
441 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {}
442 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {}
443 * }
444 * }
445 * </pre>
446 * class EnumMapping provides mapping data and support methods for this translation.
447 */
448 class EnumMapping {
449 EnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) {
450 this.forEnum = forEnum;
451 this.values = new LinkedHashMap<>();
452 this.pos = pos;
453 Name varName = names
454 .fromString(target.syntheticNameChar() +
455 "SwitchMap" +
456 target.syntheticNameChar() +
457 writer.xClassName(forEnum.type).toString()
458 .replace('/', '.')
459 .replace('.', target.syntheticNameChar()));
460 ClassSymbol outerCacheClass = outerCacheClass();
461 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL,
462 varName,
463 new ArrayType(syms.intType, syms.arrayClass),
464 outerCacheClass);
465 enterSynthetic(pos, mapVar, outerCacheClass.members());
466 }
467
468 DiagnosticPosition pos = null;
469
470 // the next value to use
471 int next = 1; // 0 (unused map elements) go to the default label
472
473 // the enum for which this is a map
474 final TypeSymbol forEnum;
475
476 // the field containing the map
477 final VarSymbol mapVar;
478
479 // the mapped values
480 final Map<VarSymbol,Integer> values;
481
482 JCLiteral forConstant(VarSymbol v) {
483 Integer result = values.get(v);
484 if (result == null)
485 values.put(v, result = next++);
486 return make.Literal(result);
487 }
488
489 // generate the field initializer for the map
490 void translate() {
491 make.at(pos.getStartPosition());
492 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner);
493
494 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length];
495 MethodSymbol valuesMethod = lookupMethod(pos,
496 names.values,
497 forEnum.type,
498 List.<Type>nil());
499 JCExpression size = make // Color.values().length
500 .Select(make.App(make.QualIdent(valuesMethod)),
501 syms.lengthVar);
502 JCExpression mapVarInit = make
503 .NewArray(make.Type(syms.intType), List.of(size), null)
504 .setType(new ArrayType(syms.intType, syms.arrayClass));
505
506 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {}
507 ListBuffer<JCStatement> stmts = new ListBuffer<>();
508 Symbol ordinalMethod = lookupMethod(pos,
509 names.ordinal,
510 forEnum.type,
511 List.<Type>nil());
512 List<JCCatch> catcher = List.<JCCatch>nil()
513 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex,
514 syms.noSuchFieldErrorType,
515 syms.noSymbol),
516 null),
517 make.Block(0, List.<JCStatement>nil())));
518 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) {
519 VarSymbol enumerator = e.getKey();
520 Integer mappedValue = e.getValue();
521 JCExpression assign = make
522 .Assign(make.Indexed(mapVar,
523 make.App(make.Select(make.QualIdent(enumerator),
524 ordinalMethod))),
525 make.Literal(mappedValue))
526 .setType(syms.intType);
527 JCStatement exec = make.Exec(assign);
528 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null);
529 stmts.append(_try);
530 }
531
532 owner.defs = owner.defs
533 .prepend(make.Block(STATIC, stmts.toList()))
534 .prepend(make.VarDef(mapVar, mapVarInit));
535 }
536 }
537
538
539 /**************************************************************************
540 * Tree building blocks
541 *************************************************************************/
542
543 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching
544 * pos as make_pos, for use in diagnostics.
545 **/
546 TreeMaker make_at(DiagnosticPosition pos) {
547 make_pos = pos;
548 return make.at(pos);
549 }
550
551 /** Make an attributed tree representing a literal. This will be an
552 * Ident node in the case of boolean literals, a Literal node in all
553 * other cases.
554 * @param type The literal's type.
555 * @param value The literal's value.
556 */
557 JCExpression makeLit(Type type, Object value) {
558 return make.Literal(type.getTag(), value).setType(type.constType(value));
559 }
560
561 /** Make an attributed tree representing null.
562 */
563 JCExpression makeNull() {
564 return makeLit(syms.botType, null);
565 }
566
567 /** Make an attributed class instance creation expression.
568 * @param ctype The class type.
569 * @param args The constructor arguments.
570 */
571 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
572 JCNewClass tree = make.NewClass(null,
573 null, make.QualIdent(ctype.tsym), args, null);
574 tree.constructor = rs.resolveConstructor(
575 make_pos, attrEnv, ctype, TreeInfo.types(args), List.<Type>nil());
576 tree.type = ctype;
577 return tree;
578 }
579
580 /** Make an attributed unary expression.
581 * @param optag The operators tree tag.
582 * @param arg The operator's argument.
583 */
584 JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) {
585 JCUnary tree = make.Unary(optag, arg);
586 tree.operator = operators.resolveUnary(tree, optag, arg.type);
587 tree.type = tree.operator.type.getReturnType();
588 return tree;
589 }
590
591 /** Make an attributed binary expression.
592 * @param optag The operators tree tag.
593 * @param lhs The operator's left argument.
594 * @param rhs The operator's right argument.
595 */
596 JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) {
597 JCBinary tree = make.Binary(optag, lhs, rhs);
598 tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type);
599 tree.type = tree.operator.type.getReturnType();
600 return tree;
601 }
602
603 /** Make an attributed assignop expression.
604 * @param optag The operators tree tag.
605 * @param lhs The operator's left argument.
606 * @param rhs The operator's right argument.
607 */
608 JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) {
609 JCAssignOp tree = make.Assignop(optag, lhs, rhs);
610 tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type);
611 tree.type = lhs.type;
612 return tree;
613 }
614
615 /** Convert tree into string object, unless it has already a
616 * reference type..
617 */
618 JCExpression makeString(JCExpression tree) {
619 if (!tree.type.isPrimitiveOrVoid()) {
620 return tree;
621 } else {
622 Symbol valueOfSym = lookupMethod(tree.pos(),
623 names.valueOf,
624 syms.stringType,
625 List.of(tree.type));
626 return make.App(make.QualIdent(valueOfSym), List.of(tree));
627 }
628 }
629
630 /** Create an empty anonymous class definition and enter and complete
631 * its symbol. Return the class definition's symbol.
632 * and create
633 * @param flags The class symbol's flags
634 * @param owner The class symbol's owner
635 */
636 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) {
637 return makeEmptyClass(flags, owner, null, true);
638 }
639
640 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname,
641 boolean addToDefs) {
642 // Create class symbol.
643 ClassSymbol c = syms.defineClass(names.empty, owner);
644 if (flatname != null) {
645 c.flatname = flatname;
646 } else {
647 c.flatname = chk.localClassName(c);
648 }
649 c.sourcefile = owner.sourcefile;
650 c.completer = Completer.NULL_COMPLETER;
651 c.members_field = WriteableScope.create(c);
652 c.flags_field = flags;
653 ClassType ctype = (ClassType) c.type;
654 ctype.supertype_field = syms.objectType;
655 ctype.interfaces_field = List.nil();
656
657 JCClassDecl odef = classDef(owner);
658
659 // Enter class symbol in owner scope and compiled table.
660 enterSynthetic(odef.pos(), c, owner.members());
661 chk.putCompiled(c);
662
663 // Create class definition tree.
664 JCClassDecl cdef = make.ClassDef(
665 make.Modifiers(flags), names.empty,
666 List.<JCTypeParameter>nil(),
667 null, List.<JCExpression>nil(), List.<JCTree>nil());
668 cdef.sym = c;
669 cdef.type = c.type;
670
671 // Append class definition tree to owner's definitions.
672 if (addToDefs) odef.defs = odef.defs.prepend(cdef);
673 return cdef;
674 }
675
676 /**************************************************************************
677 * Symbol manipulation utilities
678 *************************************************************************/
679
680 /** Enter a synthetic symbol in a given scope, but complain if there was already one there.
681 * @param pos Position for error reporting.
682 * @param sym The symbol.
683 * @param s The scope.
684 */
685 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) {
686 s.enter(sym);
687 }
688
689 /** Create a fresh synthetic name within a given scope - the unique name is
690 * obtained by appending '$' chars at the end of the name until no match
691 * is found.
692 *
693 * @param name base name
694 * @param s scope in which the name has to be unique
695 * @return fresh synthetic name
696 */
697 private Name makeSyntheticName(Name name, Scope s) {
698 do {
699 name = name.append(
700 target.syntheticNameChar(),
701 names.empty);
702 } while (lookupSynthetic(name, s) != null);
703 return name;
704 }
705
706 /** Check whether synthetic symbols generated during lowering conflict
707 * with user-defined symbols.
708 *
709 * @param translatedTrees lowered class trees
710 */
711 void checkConflicts(List<JCTree> translatedTrees) {
712 for (JCTree t : translatedTrees) {
713 t.accept(conflictsChecker);
714 }
715 }
716
717 JCTree.Visitor conflictsChecker = new TreeScanner() {
718
719 TypeSymbol currentClass;
720
721 @Override
722 public void visitMethodDef(JCMethodDecl that) {
723 chk.checkConflicts(that.pos(), that.sym, currentClass);
724 super.visitMethodDef(that);
725 }
726
727 @Override
728 public void visitVarDef(JCVariableDecl that) {
729 if (that.sym.owner.kind == TYP) {
730 chk.checkConflicts(that.pos(), that.sym, currentClass);
731 }
732 super.visitVarDef(that);
733 }
734
735 @Override
736 public void visitClassDef(JCClassDecl that) {
737 TypeSymbol prevCurrentClass = currentClass;
738 currentClass = that.sym;
739 try {
740 super.visitClassDef(that);
741 }
742 finally {
743 currentClass = prevCurrentClass;
744 }
745 }
746 };
747
748 /** Look up a synthetic name in a given scope.
749 * @param s The scope.
750 * @param name The name.
751 */
752 private Symbol lookupSynthetic(Name name, Scope s) {
753 Symbol sym = s.findFirst(name);
754 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym;
755 }
756
757 /** Look up a method in a given scope.
758 */
759 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) {
760 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.<Type>nil());
761 }
762
763 /** Look up a constructor.
764 */
765 private MethodSymbol lookupConstructor(DiagnosticPosition pos, Type qual, List<Type> args) {
766 return rs.resolveInternalConstructor(pos, attrEnv, qual, args, null);
767 }
768
769 /** Look up a field.
770 */
771 private VarSymbol lookupField(DiagnosticPosition pos, Type qual, Name name) {
772 return rs.resolveInternalField(pos, attrEnv, qual, name);
773 }
774
775 /** Anon inner classes are used as access constructor tags.
776 * accessConstructorTag will use an existing anon class if one is available,
777 * and synthethise a class (with makeEmptyClass) if one is not available.
778 * However, there is a small possibility that an existing class will not
779 * be generated as expected if it is inside a conditional with a constant
780 * expression. If that is found to be the case, create an empty class tree here.
781 */
782 private void checkAccessConstructorTags() {
783 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) {
784 ClassSymbol c = l.head;
785 if (isTranslatedClassAvailable(c))
786 continue;
787 // Create class definition tree.
788 JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC,
789 c.outermostClass(), c.flatname, false);
790 swapAccessConstructorTag(c, cdec.sym);
791 translated.append(cdec);
792 }
793 }
794 // where
795 private boolean isTranslatedClassAvailable(ClassSymbol c) {
796 for (JCTree tree: translated) {
797 if (tree.hasTag(CLASSDEF)
798 && ((JCClassDecl) tree).sym == c) {
799 return true;
800 }
801 }
802 return false;
803 }
804
805 void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) {
806 for (MethodSymbol methodSymbol : accessConstrs.values()) {
807 Assert.check(methodSymbol.type.hasTag(METHOD));
808 MethodType oldMethodType =
809 (MethodType)methodSymbol.type;
810 if (oldMethodType.argtypes.head.tsym == oldCTag)
811 methodSymbol.type =
812 types.createMethodTypeWithParameters(oldMethodType,
813 oldMethodType.getParameterTypes().tail
814 .prepend(newCTag.erasure(types)));
815 }
816 }
817
818 /**************************************************************************
819 * Access methods
820 *************************************************************************/
821
822 /** A mapping from symbols to their access numbers.
823 */
824 private Map<Symbol,Integer> accessNums;
825
826 /** A mapping from symbols to an array of access symbols, indexed by
827 * access code.
828 */
829 private Map<Symbol,MethodSymbol[]> accessSyms;
830
831 /** A mapping from (constructor) symbols to access constructor symbols.
832 */
833 private Map<Symbol,MethodSymbol> accessConstrs;
834
835 /** A list of all class symbols used for access constructor tags.
836 */
837 private List<ClassSymbol> accessConstrTags;
838
839 /** A queue for all accessed symbols.
840 */
841 private ListBuffer<Symbol> accessed;
842
843 /** return access code for identifier,
844 * @param tree The tree representing the identifier use.
845 * @param enclOp The closest enclosing operation node of tree,
846 * null if tree is not a subtree of an operation.
847 */
848 private static int accessCode(JCTree tree, JCTree enclOp) {
849 if (enclOp == null)
850 return AccessCode.DEREF.code;
851 else if (enclOp.hasTag(ASSIGN) &&
852 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs))
853 return AccessCode.ASSIGN.code;
854 else if ((enclOp.getTag().isIncOrDecUnaryOp() || enclOp.getTag().isAssignop()) &&
855 tree == TreeInfo.skipParens(((JCOperatorExpression) enclOp).getOperand(LEFT)))
856 return (((JCOperatorExpression) enclOp).operator).getAccessCode(enclOp.getTag());
857 else
858 return AccessCode.DEREF.code;
859 }
860
861 /** Return binary operator that corresponds to given access code.
862 */
863 private OperatorSymbol binaryAccessOperator(int acode, Tag tag) {
864 return operators.lookupBinaryOp(op -> op.getAccessCode(tag) == acode);
865 }
866
867 /** Return tree tag for assignment operation corresponding
868 * to given binary operator.
869 */
870 private static JCTree.Tag treeTag(OperatorSymbol operator) {
871 switch (operator.opcode) {
872 case ByteCodes.ior: case ByteCodes.lor:
873 return BITOR_ASG;
874 case ByteCodes.ixor: case ByteCodes.lxor:
875 return BITXOR_ASG;
876 case ByteCodes.iand: case ByteCodes.land:
877 return BITAND_ASG;
878 case ByteCodes.ishl: case ByteCodes.lshl:
879 case ByteCodes.ishll: case ByteCodes.lshll:
880 return SL_ASG;
881 case ByteCodes.ishr: case ByteCodes.lshr:
882 case ByteCodes.ishrl: case ByteCodes.lshrl:
883 return SR_ASG;
884 case ByteCodes.iushr: case ByteCodes.lushr:
885 case ByteCodes.iushrl: case ByteCodes.lushrl:
886 return USR_ASG;
887 case ByteCodes.iadd: case ByteCodes.ladd:
888 case ByteCodes.fadd: case ByteCodes.dadd:
889 case ByteCodes.string_add:
890 return PLUS_ASG;
891 case ByteCodes.isub: case ByteCodes.lsub:
892 case ByteCodes.fsub: case ByteCodes.dsub:
893 return MINUS_ASG;
894 case ByteCodes.imul: case ByteCodes.lmul:
895 case ByteCodes.fmul: case ByteCodes.dmul:
896 return MUL_ASG;
897 case ByteCodes.idiv: case ByteCodes.ldiv:
898 case ByteCodes.fdiv: case ByteCodes.ddiv:
899 return DIV_ASG;
900 case ByteCodes.imod: case ByteCodes.lmod:
901 case ByteCodes.fmod: case ByteCodes.dmod:
902 return MOD_ASG;
903 default:
904 throw new AssertionError();
905 }
906 }
907
908 /** The name of the access method with number `anum' and access code `acode'.
909 */
910 Name accessName(int anum, int acode) {
911 return names.fromString(
912 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10);
913 }
914
915 /** Return access symbol for a private or protected symbol from an inner class.
916 * @param sym The accessed private symbol.
917 * @param tree The accessing tree.
918 * @param enclOp The closest enclosing operation node of tree,
919 * null if tree is not a subtree of an operation.
920 * @param protAccess Is access to a protected symbol in another
921 * package?
922 * @param refSuper Is access via a (qualified) C.super?
923 */
924 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp,
925 boolean protAccess, boolean refSuper) {
926 ClassSymbol accOwner = refSuper && protAccess
927 // For access via qualified super (T.super.x), place the
928 // access symbol on T.
929 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym
930 // Otherwise pretend that the owner of an accessed
931 // protected symbol is the enclosing class of the current
932 // class which is a subclass of the symbol's owner.
933 : accessClass(sym, protAccess, tree);
934
935 Symbol vsym = sym;
936 if (sym.owner != accOwner) {
937 vsym = sym.clone(accOwner);
938 actualSymbols.put(vsym, sym);
939 }
940
941 Integer anum // The access number of the access method.
942 = accessNums.get(vsym);
943 if (anum == null) {
944 anum = accessed.length();
945 accessNums.put(vsym, anum);
946 accessSyms.put(vsym, new MethodSymbol[AccessCode.numberOfAccessCodes]);
947 accessed.append(vsym);
948 // System.out.println("accessing " + vsym + " in " + vsym.location());
949 }
950
951 int acode; // The access code of the access method.
952 List<Type> argtypes; // The argument types of the access method.
953 Type restype; // The result type of the access method.
954 List<Type> thrown; // The thrown exceptions of the access method.
955 switch (vsym.kind) {
956 case VAR:
957 acode = accessCode(tree, enclOp);
958 if (acode >= AccessCode.FIRSTASGOP.code) {
959 OperatorSymbol operator = binaryAccessOperator(acode, enclOp.getTag());
960 if (operator.opcode == string_add)
961 argtypes = List.of(syms.objectType);
962 else
963 argtypes = operator.type.getParameterTypes().tail;
964 } else if (acode == AccessCode.ASSIGN.code)
965 argtypes = List.of(vsym.erasure(types));
966 else
967 argtypes = List.nil();
968 restype = vsym.erasure(types);
969 thrown = List.nil();
970 break;
971 case MTH:
972 acode = AccessCode.DEREF.code;
973 argtypes = vsym.erasure(types).getParameterTypes();
974 restype = vsym.erasure(types).getReturnType();
975 thrown = vsym.type.getThrownTypes();
976 break;
977 default:
978 throw new AssertionError();
979 }
980
981 // For references via qualified super, increment acode by one,
982 // making it odd.
983 if (protAccess && refSuper) acode++;
984
985 // Instance access methods get instance as first parameter.
986 // For protected symbols this needs to be the instance as a member
987 // of the type containing the accessed symbol, not the class
988 // containing the access method.
989 if ((vsym.flags() & STATIC) == 0) {
990 argtypes = argtypes.prepend(vsym.owner.erasure(types));
991 }
992 MethodSymbol[] accessors = accessSyms.get(vsym);
993 MethodSymbol accessor = accessors[acode];
994 if (accessor == null) {
995 accessor = new MethodSymbol(
996 STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0),
997 accessName(anum.intValue(), acode),
998 new MethodType(argtypes, restype, thrown, syms.methodClass),
999 accOwner);
1000 enterSynthetic(tree.pos(), accessor, accOwner.members());
1001 accessors[acode] = accessor;
1002 }
1003 return accessor;
1004 }
1005
1006 /** The qualifier to be used for accessing a symbol in an outer class.
1007 * This is either C.sym or C.this.sym, depending on whether or not
1008 * sym is static.
1009 * @param sym The accessed symbol.
1010 */
1011 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) {
1012 return (sym.flags() & STATIC) != 0
1013 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner))
1014 : makeOwnerThis(pos, sym, true);
1015 }
1016
1017 /** Do we need an access method to reference private symbol?
1018 */
1019 boolean needsPrivateAccess(Symbol sym) {
1020 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) {
1021 return false;
1022 } else if (sym.name == names.init && sym.owner.isLocal()) {
1023 // private constructor in local class: relax protection
1024 sym.flags_field &= ~PRIVATE;
1025 return false;
1026 } else {
1027 return true;
1028 }
1029 }
1030
1031 /** Do we need an access method to reference symbol in other package?
1032 */
1033 boolean needsProtectedAccess(Symbol sym, JCTree tree) {
1034 if ((sym.flags() & PROTECTED) == 0 ||
1035 sym.owner.owner == currentClass.owner || // fast special case
1036 sym.packge() == currentClass.packge())
1037 return false;
1038 if (!currentClass.isSubClass(sym.owner, types))
1039 return true;
1040 if ((sym.flags() & STATIC) != 0 ||
1041 !tree.hasTag(SELECT) ||
1042 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super)
1043 return false;
1044 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types);
1045 }
1046
1047 /** The class in which an access method for given symbol goes.
1048 * @param sym The access symbol
1049 * @param protAccess Is access to a protected symbol in another
1050 * package?
1051 */
1052 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) {
1053 if (protAccess) {
1054 Symbol qualifier = null;
1055 ClassSymbol c = currentClass;
1056 if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) {
1057 qualifier = ((JCFieldAccess) tree).selected.type.tsym;
1058 while (!qualifier.isSubClass(c, types)) {
1059 c = c.owner.enclClass();
1060 }
1061 return c;
1062 } else {
1063 while (!c.isSubClass(sym.owner, types)) {
1064 c = c.owner.enclClass();
1065 }
1066 }
1067 return c;
1068 } else {
1069 // the symbol is private
1070 return sym.owner.enclClass();
1071 }
1072 }
1073
1074 private void addPrunedInfo(JCTree tree) {
1075 List<JCTree> infoList = prunedTree.get(currentClass);
1076 infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree);
1077 prunedTree.put(currentClass, infoList);
1078 }
1079
1080 /** Ensure that identifier is accessible, return tree accessing the identifier.
1081 * @param sym The accessed symbol.
1082 * @param tree The tree referring to the symbol.
1083 * @param enclOp The closest enclosing operation node of tree,
1084 * null if tree is not a subtree of an operation.
1085 * @param refSuper Is access via a (qualified) C.super?
1086 */
1087 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) {
1088 // Access a free variable via its proxy, or its proxy's proxy
1089 while (sym.kind == VAR && sym.owner.kind == MTH &&
1090 sym.owner.enclClass() != currentClass) {
1091 // A constant is replaced by its constant value.
1092 Object cv = ((VarSymbol)sym).getConstValue();
1093 if (cv != null) {
1094 make.at(tree.pos);
1095 return makeLit(sym.type, cv);
1096 }
1097 // Otherwise replace the variable by its proxy.
1098 sym = proxies.findFirst(proxyName(sym.name));
1099 Assert.check(sym != null && (sym.flags_field & FINAL) != 0);
1100 tree = make.at(tree.pos).Ident(sym);
1101 }
1102 JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null;
1103 switch (sym.kind) {
1104 case TYP:
1105 if (sym.owner.kind != PCK) {
1106 // Convert type idents to
1107 // <flat name> or <package name> . <flat name>
1108 Name flatname = Convert.shortName(sym.flatName());
1109 while (base != null &&
1110 TreeInfo.symbol(base) != null &&
1111 TreeInfo.symbol(base).kind != PCK) {
1112 base = (base.hasTag(SELECT))
1113 ? ((JCFieldAccess) base).selected
1114 : null;
1115 }
1116 if (tree.hasTag(IDENT)) {
1117 ((JCIdent) tree).name = flatname;
1118 } else if (base == null) {
1119 tree = make.at(tree.pos).Ident(sym);
1120 ((JCIdent) tree).name = flatname;
1121 } else {
1122 ((JCFieldAccess) tree).selected = base;
1123 ((JCFieldAccess) tree).name = flatname;
1124 }
1125 }
1126 break;
1127 case MTH: case VAR:
1128 if (sym.owner.kind == TYP) {
1129
1130 // Access methods are required for
1131 // - private members,
1132 // - protected members in a superclass of an
1133 // enclosing class contained in another package.
1134 // - all non-private members accessed via a qualified super.
1135 boolean protAccess = refSuper && !needsPrivateAccess(sym)
1136 || needsProtectedAccess(sym, tree);
1137 boolean accReq = protAccess || needsPrivateAccess(sym);
1138
1139 // A base has to be supplied for
1140 // - simple identifiers accessing variables in outer classes.
1141 boolean baseReq =
1142 base == null &&
1143 sym.owner != syms.predefClass &&
1144 !sym.isMemberOf(currentClass, types);
1145
1146 if (accReq || baseReq) {
1147 make.at(tree.pos);
1148
1149 // Constants are replaced by their constant value.
1150 if (sym.kind == VAR) {
1151 Object cv = ((VarSymbol)sym).getConstValue();
1152 if (cv != null) {
1153 addPrunedInfo(tree);
1154 return makeLit(sym.type, cv);
1155 }
1156 }
1157
1158 // Private variables and methods are replaced by calls
1159 // to their access methods.
1160 if (accReq) {
1161 List<JCExpression> args = List.nil();
1162 if ((sym.flags() & STATIC) == 0) {
1163 // Instance access methods get instance
1164 // as first parameter.
1165 if (base == null)
1166 base = makeOwnerThis(tree.pos(), sym, true);
1167 args = args.prepend(base);
1168 base = null; // so we don't duplicate code
1169 }
1170 Symbol access = accessSymbol(sym, tree,
1171 enclOp, protAccess,
1172 refSuper);
1173 JCExpression receiver = make.Select(
1174 base != null ? base : make.QualIdent(access.owner),
1175 access);
1176 return make.App(receiver, args);
1177
1178 // Other accesses to members of outer classes get a
1179 // qualifier.
1180 } else if (baseReq) {
1181 return make.at(tree.pos).Select(
1182 accessBase(tree.pos(), sym), sym).setType(tree.type);
1183 }
1184 }
1185 } else if (sym.owner.kind == MTH && lambdaTranslationMap != null) {
1186 //sym is a local variable - check the lambda translation map to
1187 //see if sym has been translated to something else in the current
1188 //scope (by LambdaToMethod)
1189 Symbol translatedSym = lambdaTranslationMap.get(sym);
1190 if (translatedSym != null) {
1191 tree = make.at(tree.pos).Ident(translatedSym);
1192 }
1193 }
1194 }
1195 return tree;
1196 }
1197
1198 /** Ensure that identifier is accessible, return tree accessing the identifier.
1199 * @param tree The identifier tree.
1200 */
1201 JCExpression access(JCExpression tree) {
1202 Symbol sym = TreeInfo.symbol(tree);
1203 return sym == null ? tree : access(sym, tree, null, false);
1204 }
1205
1206 /** Return access constructor for a private constructor,
1207 * or the constructor itself, if no access constructor is needed.
1208 * @param pos The position to report diagnostics, if any.
1209 * @param constr The private constructor.
1210 */
1211 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) {
1212 if (needsPrivateAccess(constr)) {
1213 ClassSymbol accOwner = constr.owner.enclClass();
1214 MethodSymbol aconstr = accessConstrs.get(constr);
1215 if (aconstr == null) {
1216 List<Type> argtypes = constr.type.getParameterTypes();
1217 if ((accOwner.flags_field & ENUM) != 0)
1218 argtypes = argtypes
1219 .prepend(syms.intType)
1220 .prepend(syms.stringType);
1221 aconstr = new MethodSymbol(
1222 SYNTHETIC,
1223 names.init,
1224 new MethodType(
1225 argtypes.append(
1226 accessConstructorTag().erasure(types)),
1227 constr.type.getReturnType(),
1228 constr.type.getThrownTypes(),
1229 syms.methodClass),
1230 accOwner);
1231 enterSynthetic(pos, aconstr, accOwner.members());
1232 accessConstrs.put(constr, aconstr);
1233 accessed.append(constr);
1234 }
1235 return aconstr;
1236 } else {
1237 return constr;
1238 }
1239 }
1240
1241 /** Return an anonymous class nested in this toplevel class.
1242 */
1243 ClassSymbol accessConstructorTag() {
1244 ClassSymbol topClass = currentClass.outermostClass();
1245 ModuleSymbol topModle = topClass.packge().modle;
1246 Name flatname = names.fromString("" + topClass.getQualifiedName() +
1247 target.syntheticNameChar() +
1248 "1");
1249 ClassSymbol ctag = chk.getCompiled(topModle, flatname);
1250 if (ctag == null)
1251 ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym;
1252 // keep a record of all tags, to verify that all are generated as required
1253 accessConstrTags = accessConstrTags.prepend(ctag);
1254 return ctag;
1255 }
1256
1257 /** Add all required access methods for a private symbol to enclosing class.
1258 * @param sym The symbol.
1259 */
1260 void makeAccessible(Symbol sym) {
1261 JCClassDecl cdef = classDef(sym.owner.enclClass());
1262 if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner);
1263 if (sym.name == names.init) {
1264 cdef.defs = cdef.defs.prepend(
1265 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym)));
1266 } else {
1267 MethodSymbol[] accessors = accessSyms.get(sym);
1268 for (int i = 0; i < AccessCode.numberOfAccessCodes; i++) {
1269 if (accessors[i] != null)
1270 cdef.defs = cdef.defs.prepend(
1271 accessDef(cdef.pos, sym, accessors[i], i));
1272 }
1273 }
1274 }
1275
1276 /** Construct definition of an access method.
1277 * @param pos The source code position of the definition.
1278 * @param vsym The private or protected symbol.
1279 * @param accessor The access method for the symbol.
1280 * @param acode The access code.
1281 */
1282 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) {
1283 // System.err.println("access " + vsym + " with " + accessor);//DEBUG
1284 currentClass = vsym.owner.enclClass();
1285 make.at(pos);
1286 JCMethodDecl md = make.MethodDef(accessor, null);
1287
1288 // Find actual symbol
1289 Symbol sym = actualSymbols.get(vsym);
1290 if (sym == null) sym = vsym;
1291
1292 JCExpression ref; // The tree referencing the private symbol.
1293 List<JCExpression> args; // Any additional arguments to be passed along.
1294 if ((sym.flags() & STATIC) != 0) {
1295 ref = make.Ident(sym);
1296 args = make.Idents(md.params);
1297 } else {
1298 JCExpression site = make.Ident(md.params.head);
1299 if (acode % 2 != 0) {
1300 //odd access codes represent qualified super accesses - need to
1301 //emit reference to the direct superclass, even if the refered
1302 //member is from an indirect superclass (JLS 13.1)
1303 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type)));
1304 }
1305 ref = make.Select(site, sym);
1306 args = make.Idents(md.params.tail);
1307 }
1308 JCStatement stat; // The statement accessing the private symbol.
1309 if (sym.kind == VAR) {
1310 // Normalize out all odd access codes by taking floor modulo 2:
1311 int acode1 = acode - (acode & 1);
1312
1313 JCExpression expr; // The access method's return value.
1314 AccessCode aCode = AccessCode.getFromCode(acode1);
1315 switch (aCode) {
1316 case DEREF:
1317 expr = ref;
1318 break;
1319 case ASSIGN:
1320 expr = make.Assign(ref, args.head);
1321 break;
1322 case PREINC: case POSTINC: case PREDEC: case POSTDEC:
1323 expr = makeUnary(aCode.tag, ref);
1324 break;
1325 default:
1326 expr = make.Assignop(
1327 treeTag(binaryAccessOperator(acode1, JCTree.Tag.NO_TAG)), ref, args.head);
1328 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1, JCTree.Tag.NO_TAG);
1329 }
1330 stat = make.Return(expr.setType(sym.type));
1331 } else {
1332 stat = make.Call(make.App(ref, args));
1333 }
1334 md.body = make.Block(0, List.of(stat));
1335
1336 // Make sure all parameters, result types and thrown exceptions
1337 // are accessible.
1338 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail)
1339 l.head.vartype = access(l.head.vartype);
1340 md.restype = access(md.restype);
1341 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail)
1342 l.head = access(l.head);
1343
1344 return md;
1345 }
1346
1347 /** Construct definition of an access constructor.
1348 * @param pos The source code position of the definition.
1349 * @param constr The private constructor.
1350 * @param accessor The access method for the constructor.
1351 */
1352 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) {
1353 make.at(pos);
1354 JCMethodDecl md = make.MethodDef(accessor,
1355 accessor.externalType(types),
1356 null);
1357 JCIdent callee = make.Ident(names._this);
1358 callee.sym = constr;
1359 callee.type = constr.type;
1360 md.body =
1361 make.Block(0, List.<JCStatement>of(
1362 make.Call(
1363 make.App(
1364 callee,
1365 make.Idents(md.params.reverse().tail.reverse())))));
1366 return md;
1367 }
1368
1369 /**************************************************************************
1370 * Free variables proxies and this$n
1371 *************************************************************************/
1372
1373 /** A scope containing all free variable proxies for currently translated
1374 * class, as well as its this$n symbol (if needed).
1375 * Proxy scopes are nested in the same way classes are.
1376 * Inside a constructor, proxies and any this$n symbol are duplicated
1377 * in an additional innermost scope, where they represent the constructor
1378 * parameters.
1379 */
1380 WriteableScope proxies;
1381
1382 /** A scope containing all unnamed resource variables/saved
1383 * exception variables for translated TWR blocks
1384 */
1385 WriteableScope twrVars;
1386
1387 /** A stack containing the this$n field of the currently translated
1388 * classes (if needed) in innermost first order.
1389 * Inside a constructor, proxies and any this$n symbol are duplicated
1390 * in an additional innermost scope, where they represent the constructor
1391 * parameters.
1392 */
1393 List<VarSymbol> outerThisStack;
1394
1395 /** The name of a free variable proxy.
1396 */
1397 Name proxyName(Name name) {
1398 return names.fromString("val" + target.syntheticNameChar() + name);
1399 }
1400
1401 /** Proxy definitions for all free variables in given list, in reverse order.
1402 * @param pos The source code position of the definition.
1403 * @param freevars The free variables.
1404 * @param owner The class in which the definitions go.
1405 */
1406 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) {
1407 return freevarDefs(pos, freevars, owner, 0);
1408 }
1409
1410 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner,
1411 long additionalFlags) {
1412 long flags = FINAL | SYNTHETIC | additionalFlags;
1413 List<JCVariableDecl> defs = List.nil();
1414 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) {
1415 VarSymbol v = l.head;
1416 VarSymbol proxy = new VarSymbol(
1417 flags, proxyName(v.name), v.erasure(types), owner);
1418 proxies.enter(proxy);
1419 JCVariableDecl vd = make.at(pos).VarDef(proxy, null);
1420 vd.vartype = access(vd.vartype);
1421 defs = defs.prepend(vd);
1422 }
1423 return defs;
1424 }
1425
1426 /** The name of a this$n field
1427 * @param type The class referenced by the this$n field
1428 */
1429 Name outerThisName(Type type, Symbol owner) {
1430 Type t = type.getEnclosingType();
1431 int nestingLevel = 0;
1432 while (t.hasTag(CLASS)) {
1433 t = t.getEnclosingType();
1434 nestingLevel++;
1435 }
1436 Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel);
1437 while (owner.kind == TYP && ((ClassSymbol)owner).members().findFirst(result) != null)
1438 result = names.fromString(result.toString() + target.syntheticNameChar());
1439 return result;
1440 }
1441
1442 private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) {
1443 Type target = types.erasure(owner.enclClass().type.getEnclosingType());
1444 VarSymbol outerThis =
1445 new VarSymbol(flags, outerThisName(target, owner), target, owner);
1446 outerThisStack = outerThisStack.prepend(outerThis);
1447 return outerThis;
1448 }
1449
1450 private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) {
1451 JCVariableDecl vd = make.at(pos).VarDef(sym, null);
1452 vd.vartype = access(vd.vartype);
1453 return vd;
1454 }
1455
1456 /** Definition for this$n field.
1457 * @param pos The source code position of the definition.
1458 * @param owner The method in which the definition goes.
1459 */
1460 JCVariableDecl outerThisDef(int pos, MethodSymbol owner) {
1461 ClassSymbol c = owner.enclClass();
1462 boolean isMandated =
1463 // Anonymous constructors
1464 (owner.isConstructor() && owner.isAnonymous()) ||
1465 // Constructors of non-private inner member classes
1466 (owner.isConstructor() && c.isInner() &&
1467 !c.isPrivate() && !c.isStatic());
1468 long flags =
1469 FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER;
1470 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags);
1471 owner.extraParams = owner.extraParams.prepend(outerThis);
1472 return makeOuterThisVarDecl(pos, outerThis);
1473 }
1474
1475 /** Definition for this$n field.
1476 * @param pos The source code position of the definition.
1477 * @param owner The class in which the definition goes.
1478 */
1479 JCVariableDecl outerThisDef(int pos, ClassSymbol owner) {
1480 VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC);
1481 return makeOuterThisVarDecl(pos, outerThis);
1482 }
1483
1484 /** Return a list of trees that load the free variables in given list,
1485 * in reverse order.
1486 * @param pos The source code position to be used for the trees.
1487 * @param freevars The list of free variables.
1488 */
1489 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) {
1490 List<JCExpression> args = List.nil();
1491 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail)
1492 args = args.prepend(loadFreevar(pos, l.head));
1493 return args;
1494 }
1495 //where
1496 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) {
1497 return access(v, make.at(pos).Ident(v), null, false);
1498 }
1499
1500 /** Construct a tree simulating the expression {@code C.this}.
1501 * @param pos The source code position to be used for the tree.
1502 * @param c The qualifier class.
1503 */
1504 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) {
1505 if (currentClass == c) {
1506 // in this case, `this' works fine
1507 return make.at(pos).This(c.erasure(types));
1508 } else {
1509 // need to go via this$n
1510 return makeOuterThis(pos, c);
1511 }
1512 }
1513
1514 /**
1515 * Optionally replace a try statement with the desugaring of a
1516 * try-with-resources statement. The canonical desugaring of
1517 *
1518 * try ResourceSpecification
1519 * Block
1520 *
1521 * is
1522 *
1523 * {
1524 * final VariableModifiers_minus_final R #resource = Expression;
1525 * Throwable #primaryException = null;
1526 *
1527 * try ResourceSpecificationtail
1528 * Block
1529 * catch (Throwable #t) {
1530 * #primaryException = t;
1531 * throw #t;
1532 * } finally {
1533 * if (#resource != null) {
1534 * if (#primaryException != null) {
1535 * try {
1536 * #resource.close();
1537 * } catch(Throwable #suppressedException) {
1538 * #primaryException.addSuppressed(#suppressedException);
1539 * }
1540 * } else {
1541 * #resource.close();
1542 * }
1543 * }
1544 * }
1545 *
1546 * @param tree The try statement to inspect.
1547 * @return A a desugared try-with-resources tree, or the original
1548 * try block if there are no resources to manage.
1549 */
1550 JCTree makeTwrTry(JCTry tree) {
1551 make_at(tree.pos());
1552 twrVars = twrVars.dup();
1553 JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body,
1554 tree.finallyCanCompleteNormally, 0);
1555 if (tree.catchers.isEmpty() && tree.finalizer == null)
1556 result = translate(twrBlock);
1557 else
1558 result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer));
1559 twrVars = twrVars.leave();
1560 return result;
1561 }
1562
1563 private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block,
1564 boolean finallyCanCompleteNormally, int depth) {
1565 if (resources.isEmpty())
1566 return block;
1567
1568 // Add resource declaration or expression to block statements
1569 ListBuffer<JCStatement> stats = new ListBuffer<>();
1570 JCTree resource = resources.head;
1571 JCExpression expr = null;
1572 boolean resourceNonNull;
1573 if (resource instanceof JCVariableDecl) {
1574 JCVariableDecl var = (JCVariableDecl) resource;
1575 expr = make.Ident(var.sym).setType(resource.type);
1576 resourceNonNull = var.init != null && TreeInfo.skipParens(var.init).hasTag(NEWCLASS);
1577 stats.add(var);
1578 } else {
1579 Assert.check(resource instanceof JCExpression);
1580 VarSymbol syntheticTwrVar =
1581 new VarSymbol(SYNTHETIC | FINAL,
1582 makeSyntheticName(names.fromString("twrVar" +
1583 depth), twrVars),
1584 (resource.type.hasTag(BOT)) ?
1585 syms.autoCloseableType : resource.type,
1586 currentMethodSym);
1587 twrVars.enter(syntheticTwrVar);
1588 JCVariableDecl syntheticTwrVarDecl =
1589 make.VarDef(syntheticTwrVar, (JCExpression)resource);
1590 expr = (JCExpression)make.Ident(syntheticTwrVar);
1591 resourceNonNull = TreeInfo.skipParens(resource).hasTag(NEWCLASS);
1592 stats.add(syntheticTwrVarDecl);
1593 }
1594
1595 // Add primaryException declaration
1596 VarSymbol primaryException =
1597 new VarSymbol(SYNTHETIC,
1598 makeSyntheticName(names.fromString("primaryException" +
1599 depth), twrVars),
1600 syms.throwableType,
1601 currentMethodSym);
1602 twrVars.enter(primaryException);
1603 JCVariableDecl primaryExceptionTreeDecl = make.VarDef(primaryException, makeNull());
1604 stats.add(primaryExceptionTreeDecl);
1605
1606 // Create catch clause that saves exception and then rethrows it
1607 VarSymbol param =
1608 new VarSymbol(FINAL|SYNTHETIC,
1609 names.fromString("t" +
1610 target.syntheticNameChar()),
1611 syms.throwableType,
1612 currentMethodSym);
1613 JCVariableDecl paramTree = make.VarDef(param, null);
1614 JCStatement assign = make.Assignment(primaryException, make.Ident(param));
1615 JCStatement rethrowStat = make.Throw(make.Ident(param));
1616 JCBlock catchBlock = make.Block(0L, List.<JCStatement>of(assign, rethrowStat));
1617 JCCatch catchClause = make.Catch(paramTree, catchBlock);
1618
1619 int oldPos = make.pos;
1620 make.at(TreeInfo.endPos(block));
1621 JCBlock finallyClause = makeTwrFinallyClause(primaryException, expr, resourceNonNull);
1622 make.at(oldPos);
1623 JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block,
1624 finallyCanCompleteNormally, depth + 1),
1625 List.<JCCatch>of(catchClause),
1626 finallyClause);
1627 outerTry.finallyCanCompleteNormally = finallyCanCompleteNormally;
1628 stats.add(outerTry);
1629 JCBlock newBlock = make.Block(0L, stats.toList());
1630 return newBlock;
1631 }
1632
1633 /**If the estimated number of copies the close resource code in a single class is above this
1634 * threshold, generate and use a method for the close resource code, leading to smaller code.
1635 * As generating a method has overhead on its own, generating the method for cases below the
1636 * threshold could lead to an increase in code size.
1637 */
1638 public static final int USE_CLOSE_RESOURCE_METHOD_THRESHOLD = 4;
1639
1640 private JCBlock makeTwrFinallyClause(Symbol primaryException, JCExpression resource,
1641 boolean resourceNonNull) {
1642 MethodSymbol closeResource = (MethodSymbol)lookupSynthetic(dollarCloseResource,
1643 currentClass.members());
1644
1645 if (closeResource == null && shouldUseCloseResourceMethod()) {
1646 closeResource = new MethodSymbol(
1647 PRIVATE | STATIC | SYNTHETIC,
1648 dollarCloseResource,
1649 new MethodType(
1650 List.of(syms.throwableType, syms.autoCloseableType),
1651 syms.voidType,
1652 List.<Type>nil(),
1653 syms.methodClass),
1654 currentClass);
1655 enterSynthetic(resource.pos(), closeResource, currentClass.members());
1656
1657 JCMethodDecl md = make.MethodDef(closeResource, null);
1658 List<JCVariableDecl> params = md.getParameters();
1659 md.body = make.Block(0, List.<JCStatement>of(makeTwrCloseStatement(params.get(0).sym,
1660 make.Ident(params.get(1)))));
1661
1662 JCClassDecl currentClassDecl = classDef(currentClass);
1663 currentClassDecl.defs = currentClassDecl.defs.prepend(md);
1664 }
1665
1666 JCStatement closeStatement;
1667
1668 if (closeResource != null) {
1669 //$closeResource(#primaryException, #resource)
1670 closeStatement = make.Exec(make.Apply(List.<JCExpression>nil(),
1671 make.Ident(closeResource),
1672 List.of(make.Ident(primaryException),
1673 resource)
1674 ).setType(syms.voidType));
1675 } else {
1676 closeStatement = makeTwrCloseStatement(primaryException, resource);
1677 }
1678
1679 JCStatement finallyStatement;
1680
1681 if (resourceNonNull) {
1682 finallyStatement = closeStatement;
1683 } else {
1684 // if (#resource != null) { $closeResource(...); }
1685 finallyStatement = make.If(makeNonNullCheck(resource),
1686 closeStatement,
1687 null);
1688 }
1689
1690 return make.Block(0L,
1691 List.<JCStatement>of(finallyStatement));
1692 }
1693 //where:
1694 private boolean shouldUseCloseResourceMethod() {
1695 class TryFinder extends TreeScanner {
1696 int closeCount;
1697 @Override
1698 public void visitTry(JCTry tree) {
1699 boolean empty = tree.body.stats.isEmpty();
1700
1701 for (JCTree r : tree.resources) {
1702 closeCount += empty ? 1 : 2;
1703 empty = false; //with multiple resources, only the innermost try can be empty.
1704 }
1705 super.visitTry(tree);
1706 }
1707 @Override
1708 public void scan(JCTree tree) {
1709 if (useCloseResourceMethod())
1710 return;
1711 super.scan(tree);
1712 }
1713 boolean useCloseResourceMethod() {
1714 return closeCount >= USE_CLOSE_RESOURCE_METHOD_THRESHOLD;
1715 }
1716 }
1717 TryFinder tryFinder = new TryFinder();
1718 tryFinder.scan(classDef(currentClass));
1719 return tryFinder.useCloseResourceMethod();
1720 }
1721
1722 private JCStatement makeTwrCloseStatement(Symbol primaryException, JCExpression resource) {
1723 // primaryException.addSuppressed(catchException);
1724 VarSymbol catchException =
1725 new VarSymbol(SYNTHETIC, make.paramName(2),
1726 syms.throwableType,
1727 currentMethodSym);
1728 JCStatement addSuppressionStatement =
1729 make.Exec(makeCall(make.Ident(primaryException),
1730 names.addSuppressed,
1731 List.<JCExpression>of(make.Ident(catchException))));
1732
1733 // try { resource.close(); } catch (e) { primaryException.addSuppressed(e); }
1734 JCBlock tryBlock =
1735 make.Block(0L, List.<JCStatement>of(makeResourceCloseInvocation(resource)));
1736 JCVariableDecl catchExceptionDecl = make.VarDef(catchException, null);
1737 JCBlock catchBlock = make.Block(0L, List.<JCStatement>of(addSuppressionStatement));
1738 List<JCCatch> catchClauses = List.<JCCatch>of(make.Catch(catchExceptionDecl, catchBlock));
1739 JCTry tryTree = make.Try(tryBlock, catchClauses, null);
1740 tryTree.finallyCanCompleteNormally = true;
1741
1742 // if (primaryException != null) {try...} else resourceClose;
1743 JCIf closeIfStatement = make.If(makeNonNullCheck(make.Ident(primaryException)),
1744 tryTree,
1745 makeResourceCloseInvocation(resource));
1746
1747 return closeIfStatement;
1748 }
1749
1750 private JCStatement makeResourceCloseInvocation(JCExpression resource) {
1751 // convert to AutoCloseable if needed
1752 if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) {
1753 resource = convert(resource, syms.autoCloseableType);
1754 }
1755
1756 // create resource.close() method invocation
1757 JCExpression resourceClose = makeCall(resource,
1758 names.close,
1759 List.<JCExpression>nil());
1760 return make.Exec(resourceClose);
1761 }
1762
1763 private JCExpression makeNonNullCheck(JCExpression expression) {
1764 return makeBinary(NE, expression, makeNull());
1765 }
1766
1767 /** Construct a tree that represents the outer instance
1768 * {@code C.this}. Never pick the current `this'.
1769 * @param pos The source code position to be used for the tree.
1770 * @param c The qualifier class.
1771 */
1772 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) {
1773 List<VarSymbol> ots = outerThisStack;
1774 if (ots.isEmpty()) {
1775 log.error(pos, "no.encl.instance.of.type.in.scope", c);
1776 Assert.error();
1777 return makeNull();
1778 }
1779 VarSymbol ot = ots.head;
1780 JCExpression tree = access(make.at(pos).Ident(ot));
1781 TypeSymbol otc = ot.type.tsym;
1782 while (otc != c) {
1783 do {
1784 ots = ots.tail;
1785 if (ots.isEmpty()) {
1786 log.error(pos,
1787 "no.encl.instance.of.type.in.scope",
1788 c);
1789 Assert.error(); // should have been caught in Attr
1790 return tree;
1791 }
1792 ot = ots.head;
1793 } while (ot.owner != otc);
1794 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) {
1795 chk.earlyRefError(pos, c);
1796 Assert.error(); // should have been caught in Attr
1797 return makeNull();
1798 }
1799 tree = access(make.at(pos).Select(tree, ot));
1800 otc = ot.type.tsym;
1801 }
1802 return tree;
1803 }
1804
1805 /** Construct a tree that represents the closest outer instance
1806 * {@code C.this} such that the given symbol is a member of C.
1807 * @param pos The source code position to be used for the tree.
1808 * @param sym The accessed symbol.
1809 * @param preciseMatch should we accept a type that is a subtype of
1810 * sym's owner, even if it doesn't contain sym
1811 * due to hiding, overriding, or non-inheritance
1812 * due to protection?
1813 */
1814 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1815 Symbol c = sym.owner;
1816 if (preciseMatch ? sym.isMemberOf(currentClass, types)
1817 : currentClass.isSubClass(sym.owner, types)) {
1818 // in this case, `this' works fine
1819 return make.at(pos).This(c.erasure(types));
1820 } else {
1821 // need to go via this$n
1822 return makeOwnerThisN(pos, sym, preciseMatch);
1823 }
1824 }
1825
1826 /**
1827 * Similar to makeOwnerThis but will never pick "this".
1828 */
1829 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1830 Symbol c = sym.owner;
1831 List<VarSymbol> ots = outerThisStack;
1832 if (ots.isEmpty()) {
1833 log.error(pos, "no.encl.instance.of.type.in.scope", c);
1834 Assert.error();
1835 return makeNull();
1836 }
1837 VarSymbol ot = ots.head;
1838 JCExpression tree = access(make.at(pos).Ident(ot));
1839 TypeSymbol otc = ot.type.tsym;
1840 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) {
1841 do {
1842 ots = ots.tail;
1843 if (ots.isEmpty()) {
1844 log.error(pos,
1845 "no.encl.instance.of.type.in.scope",
1846 c);
1847 Assert.error();
1848 return tree;
1849 }
1850 ot = ots.head;
1851 } while (ot.owner != otc);
1852 tree = access(make.at(pos).Select(tree, ot));
1853 otc = ot.type.tsym;
1854 }
1855 return tree;
1856 }
1857
1858 /** Return tree simulating the assignment {@code this.name = name}, where
1859 * name is the name of a free variable.
1860 */
1861 JCStatement initField(int pos, Name name) {
1862 Iterator<Symbol> it = proxies.getSymbolsByName(name).iterator();
1863 Symbol rhs = it.next();
1864 Assert.check(rhs.owner.kind == MTH);
1865 Symbol lhs = it.next();
1866 Assert.check(rhs.owner.owner == lhs.owner);
1867 make.at(pos);
1868 return
1869 make.Exec(
1870 make.Assign(
1871 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1872 make.Ident(rhs)).setType(lhs.erasure(types)));
1873 }
1874
1875 /** Return tree simulating the assignment {@code this.this$n = this$n}.
1876 */
1877 JCStatement initOuterThis(int pos) {
1878 VarSymbol rhs = outerThisStack.head;
1879 Assert.check(rhs.owner.kind == MTH);
1880 VarSymbol lhs = outerThisStack.tail.head;
1881 Assert.check(rhs.owner.owner == lhs.owner);
1882 make.at(pos);
1883 return
1884 make.Exec(
1885 make.Assign(
1886 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1887 make.Ident(rhs)).setType(lhs.erasure(types)));
1888 }
1889
1890 /**************************************************************************
1891 * Code for .class
1892 *************************************************************************/
1893
1894 /** Return the symbol of a class to contain a cache of
1895 * compiler-generated statics such as class$ and the
1896 * $assertionsDisabled flag. We create an anonymous nested class
1897 * (unless one already exists) and return its symbol. However,
1898 * for backward compatibility in 1.4 and earlier we use the
1899 * top-level class itself.
1900 */
1901 private ClassSymbol outerCacheClass() {
1902 ClassSymbol clazz = outermostClassDef.sym;
1903 Scope s = clazz.members();
1904 for (Symbol sym : s.getSymbols(NON_RECURSIVE))
1905 if (sym.kind == TYP &&
1906 sym.name == names.empty &&
1907 (sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym;
1908 return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym;
1909 }
1910
1911 /** Return symbol for "class$" method. If there is no method definition
1912 * for class$, construct one as follows:
1913 *
1914 * class class$(String x0) {
1915 * try {
1916 * return Class.forName(x0);
1917 * } catch (ClassNotFoundException x1) {
1918 * throw new NoClassDefFoundError(x1.getMessage());
1919 * }
1920 * }
1921 */
1922 private MethodSymbol classDollarSym(DiagnosticPosition pos) {
1923 ClassSymbol outerCacheClass = outerCacheClass();
1924 MethodSymbol classDollarSym =
1925 (MethodSymbol)lookupSynthetic(classDollar,
1926 outerCacheClass.members());
1927 if (classDollarSym == null) {
1928 classDollarSym = new MethodSymbol(
1929 STATIC | SYNTHETIC,
1930 classDollar,
1931 new MethodType(
1932 List.of(syms.stringType),
1933 types.erasure(syms.classType),
1934 List.<Type>nil(),
1935 syms.methodClass),
1936 outerCacheClass);
1937 enterSynthetic(pos, classDollarSym, outerCacheClass.members());
1938
1939 JCMethodDecl md = make.MethodDef(classDollarSym, null);
1940 try {
1941 md.body = classDollarSymBody(pos, md);
1942 } catch (CompletionFailure ex) {
1943 md.body = make.Block(0, List.<JCStatement>nil());
1944 chk.completionError(pos, ex);
1945 }
1946 JCClassDecl outerCacheClassDef = classDef(outerCacheClass);
1947 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(md);
1948 }
1949 return classDollarSym;
1950 }
1951
1952 /** Generate code for class$(String name). */
1953 JCBlock classDollarSymBody(DiagnosticPosition pos, JCMethodDecl md) {
1954 MethodSymbol classDollarSym = md.sym;
1955 ClassSymbol outerCacheClass = (ClassSymbol)classDollarSym.owner;
1956
1957 JCBlock returnResult;
1958
1959 // cache the current loader in cl$
1960 // clsym = "private static ClassLoader cl$"
1961 VarSymbol clsym = new VarSymbol(STATIC | SYNTHETIC,
1962 names.fromString("cl" + target.syntheticNameChar()),
1963 syms.classLoaderType,
1964 outerCacheClass);
1965 enterSynthetic(pos, clsym, outerCacheClass.members());
1966
1967 // emit "private static ClassLoader cl$;"
1968 JCVariableDecl cldef = make.VarDef(clsym, null);
1969 JCClassDecl outerCacheClassDef = classDef(outerCacheClass);
1970 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cldef);
1971
1972 // newcache := "new cache$1[0]"
1973 JCNewArray newcache = make.NewArray(make.Type(outerCacheClass.type),
1974 List.<JCExpression>of(make.Literal(INT, 0).setType(syms.intType)),
1975 null);
1976 newcache.type = new ArrayType(types.erasure(outerCacheClass.type),
1977 syms.arrayClass);
1978
1979 // forNameSym := java.lang.Class.forName(
1980 // String s,boolean init,ClassLoader loader)
1981 Symbol forNameSym = lookupMethod(make_pos, names.forName,
1982 types.erasure(syms.classType),
1983 List.of(syms.stringType,
1984 syms.booleanType,
1985 syms.classLoaderType));
1986 // clvalue := "(cl$ == null) ?
1987 // $newcache.getClass().getComponentType().getClassLoader() : cl$"
1988 JCExpression clvalue =
1989 make.Conditional(
1990 makeBinary(EQ, make.Ident(clsym), makeNull()),
1991 make.Assign(make.Ident(clsym),
1992 makeCall(
1993 makeCall(makeCall(newcache,
1994 names.getClass,
1995 List.<JCExpression>nil()),
1996 names.getComponentType,
1997 List.<JCExpression>nil()),
1998 names.getClassLoader,
1999 List.<JCExpression>nil())).setType(syms.classLoaderType),
2000 make.Ident(clsym)).setType(syms.classLoaderType);
2001
2002 // returnResult := "{ return Class.forName(param1, false, cl$); }"
2003 List<JCExpression> args = List.of(make.Ident(md.params.head.sym),
2004 makeLit(syms.booleanType, 0),
2005 clvalue);
2006 returnResult = make.Block(0, List.<JCStatement>of(make.Call(make.App(make.Ident(forNameSym), args))));
2007
2008 // catchParam := ClassNotFoundException e1
2009 VarSymbol catchParam =
2010 new VarSymbol(SYNTHETIC, make.paramName(1),
2011 syms.classNotFoundExceptionType,
2012 classDollarSym);
2013
2014 JCStatement rethrow;
2015 // rethrow = "throw new NoClassDefFoundError().initCause(e);
2016 JCExpression throwExpr =
2017 makeCall(makeNewClass(syms.noClassDefFoundErrorType,
2018 List.<JCExpression>nil()),
2019 names.initCause,
2020 List.<JCExpression>of(make.Ident(catchParam)));
2021 rethrow = make.Throw(throwExpr);
2022
2023 // rethrowStmt := "( $rethrow )"
2024 JCBlock rethrowStmt = make.Block(0, List.of(rethrow));
2025
2026 // catchBlock := "catch ($catchParam) $rethrowStmt"
2027 JCCatch catchBlock = make.Catch(make.VarDef(catchParam, null),
2028 rethrowStmt);
2029
2030 // tryCatch := "try $returnResult $catchBlock"
2031 JCStatement tryCatch = make.Try(returnResult,
2032 List.of(catchBlock), null);
2033
2034 return make.Block(0, List.of(tryCatch));
2035 }
2036 // where
2037 /** Create an attributed tree of the form left.name(). */
2038 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) {
2039 Assert.checkNonNull(left.type);
2040 Symbol funcsym = lookupMethod(make_pos, name, left.type,
2041 TreeInfo.types(args));
2042 return make.App(make.Select(left, funcsym), args);
2043 }
2044
2045 /** The Name Of The variable to cache T.class values.
2046 * @param sig The signature of type T.
2047 */
2048 private Name cacheName(String sig) {
2049 StringBuilder buf = new StringBuilder();
2050 if (sig.startsWith("[")) {
2051 buf = buf.append("array");
2052 while (sig.startsWith("[")) {
2053 buf = buf.append(target.syntheticNameChar());
2054 sig = sig.substring(1);
2055 }
2056 if (sig.startsWith("L")) {
2057 sig = sig.substring(0, sig.length() - 1);
2058 }
2059 } else {
2060 buf = buf.append("class" + target.syntheticNameChar());
2061 }
2062 buf = buf.append(sig.replace('.', target.syntheticNameChar()));
2063 return names.fromString(buf.toString());
2064 }
2065
2066 /** The variable symbol that caches T.class values.
2067 * If none exists yet, create a definition.
2068 * @param sig The signature of type T.
2069 * @param pos The position to report diagnostics, if any.
2070 */
2071 private VarSymbol cacheSym(DiagnosticPosition pos, String sig) {
2072 ClassSymbol outerCacheClass = outerCacheClass();
2073 Name cname = cacheName(sig);
2074 VarSymbol cacheSym =
2075 (VarSymbol)lookupSynthetic(cname, outerCacheClass.members());
2076 if (cacheSym == null) {
2077 cacheSym = new VarSymbol(
2078 STATIC | SYNTHETIC, cname, types.erasure(syms.classType), outerCacheClass);
2079 enterSynthetic(pos, cacheSym, outerCacheClass.members());
2080
2081 JCVariableDecl cacheDef = make.VarDef(cacheSym, null);
2082 JCClassDecl outerCacheClassDef = classDef(outerCacheClass);
2083 outerCacheClassDef.defs = outerCacheClassDef.defs.prepend(cacheDef);
2084 }
2085 return cacheSym;
2086 }
2087
2088 /** The tree simulating a T.class expression.
2089 * @param clazz The tree identifying type T.
2090 */
2091 private JCExpression classOf(JCTree clazz) {
2092 return classOfType(clazz.type, clazz.pos());
2093 }
2094
2095 private JCExpression classOfType(Type type, DiagnosticPosition pos) {
2096 switch (type.getTag()) {
2097 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT:
2098 case DOUBLE: case BOOLEAN: case VOID:
2099 // replace with <BoxedClass>.TYPE
2100 ClassSymbol c = types.boxedClass(type);
2101 Symbol typeSym =
2102 rs.accessBase(
2103 rs.findIdentInType(attrEnv, c.type, names.TYPE, KindSelector.VAR),
2104 pos, c.type, names.TYPE, true);
2105 if (typeSym.kind == VAR)
2106 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated
2107 return make.QualIdent(typeSym);
2108 case CLASS: case ARRAY:
2109 VarSymbol sym = new VarSymbol(
2110 STATIC | PUBLIC | FINAL, names._class,
2111 syms.classType, type.tsym);
2112 return make_at(pos).Select(make.Type(type), sym);
2113 default:
2114 throw new AssertionError();
2115 }
2116 }
2117
2118 /**************************************************************************
2119 * Code for enabling/disabling assertions.
2120 *************************************************************************/
2121
2122 private ClassSymbol assertionsDisabledClassCache;
2123
2124 /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces.
2125 */
2126 private ClassSymbol assertionsDisabledClass() {
2127 if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache;
2128
2129 assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym;
2130
2131 return assertionsDisabledClassCache;
2132 }
2133
2134 // This code is not particularly robust if the user has
2135 // previously declared a member named '$assertionsDisabled'.
2136 // The same faulty idiom also appears in the translation of
2137 // class literals above. We should report an error if a
2138 // previous declaration is not synthetic.
2139
2140 private JCExpression assertFlagTest(DiagnosticPosition pos) {
2141 // Outermost class may be either true class or an interface.
2142 ClassSymbol outermostClass = outermostClassDef.sym;
2143
2144 //only classes can hold a non-public field, look for a usable one:
2145 ClassSymbol container = !currentClass.isInterface() ? currentClass :
2146 assertionsDisabledClass();
2147
2148 VarSymbol assertDisabledSym =
2149 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled,
2150 container.members());
2151 if (assertDisabledSym == null) {
2152 assertDisabledSym =
2153 new VarSymbol(STATIC | FINAL | SYNTHETIC,
2154 dollarAssertionsDisabled,
2155 syms.booleanType,
2156 container);
2157 enterSynthetic(pos, assertDisabledSym, container.members());
2158 Symbol desiredAssertionStatusSym = lookupMethod(pos,
2159 names.desiredAssertionStatus,
2160 types.erasure(syms.classType),
2161 List.<Type>nil());
2162 JCClassDecl containerDef = classDef(container);
2163 make_at(containerDef.pos());
2164 JCExpression notStatus = makeUnary(NOT, make.App(make.Select(
2165 classOfType(types.erasure(outermostClass.type),
2166 containerDef.pos()),
2167 desiredAssertionStatusSym)));
2168 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym,
2169 notStatus);
2170 containerDef.defs = containerDef.defs.prepend(assertDisabledDef);
2171
2172 if (currentClass.isInterface()) {
2173 //need to load the assertions enabled/disabled state while
2174 //initializing the interface:
2175 JCClassDecl currentClassDef = classDef(currentClass);
2176 make_at(currentClassDef.pos());
2177 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null);
2178 JCBlock clinit = make.Block(STATIC, List.<JCStatement>of(dummy));
2179 currentClassDef.defs = currentClassDef.defs.prepend(clinit);
2180 }
2181 }
2182 make_at(pos);
2183 return makeUnary(NOT, make.Ident(assertDisabledSym));
2184 }
2185
2186
2187 /**************************************************************************
2188 * Building blocks for let expressions
2189 *************************************************************************/
2190
2191 interface TreeBuilder {
2192 JCExpression build(JCExpression arg);
2193 }
2194
2195 /** Construct an expression using the builder, with the given rval
2196 * expression as an argument to the builder. However, the rval
2197 * expression must be computed only once, even if used multiple
2198 * times in the result of the builder. We do that by
2199 * constructing a "let" expression that saves the rvalue into a
2200 * temporary variable and then uses the temporary variable in
2201 * place of the expression built by the builder. The complete
2202 * resulting expression is of the form
2203 * <pre>
2204 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>;
2205 * in (<b>BUILDER</b>(<b>TEMP</b>)))
2206 * </pre>
2207 * where <code><b>TEMP</b></code> is a newly declared variable
2208 * in the let expression.
2209 */
2210 JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) {
2211 rval = TreeInfo.skipParens(rval);
2212 switch (rval.getTag()) {
2213 case LITERAL:
2214 return builder.build(rval);
2215 case IDENT:
2216 JCIdent id = (JCIdent) rval;
2217 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH)
2218 return builder.build(rval);
2219 }
2220 Name name = TreeInfo.name(rval);
2221 if (name == names._super || name == names._this)
2222 return builder.build(rval);
2223 VarSymbol var =
2224 new VarSymbol(FINAL|SYNTHETIC,
2225 names.fromString(
2226 target.syntheticNameChar()
2227 + "" + rval.hashCode()),
2228 type,
2229 currentMethodSym);
2230 rval = convert(rval,type);
2231 JCVariableDecl def = make.VarDef(var, rval); // XXX cast
2232 JCExpression built = builder.build(make.Ident(var));
2233 JCExpression res = make.LetExpr(def, built);
2234 res.type = built.type;
2235 return res;
2236 }
2237
2238 // same as above, with the type of the temporary variable computed
2239 JCExpression abstractRval(JCExpression rval, TreeBuilder builder) {
2240 return abstractRval(rval, rval.type, builder);
2241 }
2242
2243 // same as above, but for an expression that may be used as either
2244 // an rvalue or an lvalue. This requires special handling for
2245 // Select expressions, where we place the left-hand-side of the
2246 // select in a temporary, and for Indexed expressions, where we
2247 // place both the indexed expression and the index value in temps.
2248 JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) {
2249 lval = TreeInfo.skipParens(lval);
2250 switch (lval.getTag()) {
2251 case IDENT:
2252 return builder.build(lval);
2253 case SELECT: {
2254 final JCFieldAccess s = (JCFieldAccess)lval;
2255 Symbol lid = TreeInfo.symbol(s.selected);
2256 if (lid != null && lid.kind == TYP) return builder.build(lval);
2257 return abstractRval(s.selected, new TreeBuilder() {
2258 public JCExpression build(final JCExpression selected) {
2259 return builder.build(make.Select(selected, s.sym));
2260 }
2261 });
2262 }
2263 case INDEXED: {
2264 final JCArrayAccess i = (JCArrayAccess)lval;
2265 return abstractRval(i.indexed, new TreeBuilder() {
2266 public JCExpression build(final JCExpression indexed) {
2267 return abstractRval(i.index, syms.intType, new TreeBuilder() {
2268 public JCExpression build(final JCExpression index) {
2269 JCExpression newLval = make.Indexed(indexed, index);
2270 newLval.setType(i.type);
2271 return builder.build(newLval);
2272 }
2273 });
2274 }
2275 });
2276 }
2277 case TYPECAST: {
2278 return abstractLval(((JCTypeCast)lval).expr, builder);
2279 }
2280 }
2281 throw new AssertionError(lval);
2282 }
2283
2284 // evaluate and discard the first expression, then evaluate the second.
2285 JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) {
2286 return abstractRval(expr1, new TreeBuilder() {
2287 public JCExpression build(final JCExpression discarded) {
2288 return expr2;
2289 }
2290 });
2291 }
2292
2293 /**************************************************************************
2294 * Translation methods
2295 *************************************************************************/
2296
2297 /** Visitor argument: enclosing operator node.
2298 */
2299 private JCExpression enclOp;
2300
2301 /** Visitor method: Translate a single node.
2302 * Attach the source position from the old tree to its replacement tree.
2303 */
2304 @Override
2305 public <T extends JCTree> T translate(T tree) {
2306 if (tree == null) {
2307 return null;
2308 } else {
2309 make_at(tree.pos());
2310 T result = super.translate(tree);
2311 if (endPosTable != null && result != tree) {
2312 endPosTable.replaceTree(tree, result);
2313 }
2314 return result;
2315 }
2316 }
2317
2318 /** Visitor method: Translate a single node, boxing or unboxing if needed.
2319 */
2320 public <T extends JCExpression> T translate(T tree, Type type) {
2321 return (tree == null) ? null : boxIfNeeded(translate(tree), type);
2322 }
2323
2324 /** Visitor method: Translate tree.
2325 */
2326 public <T extends JCTree> T translate(T tree, JCExpression enclOp) {
2327 JCExpression prevEnclOp = this.enclOp;
2328 this.enclOp = enclOp;
2329 T res = translate(tree);
2330 this.enclOp = prevEnclOp;
2331 return res;
2332 }
2333
2334 /** Visitor method: Translate list of trees.
2335 */
2336 public <T extends JCTree> List<T> translate(List<T> trees, JCExpression enclOp) {
2337 JCExpression prevEnclOp = this.enclOp;
2338 this.enclOp = enclOp;
2339 List<T> res = translate(trees);
2340 this.enclOp = prevEnclOp;
2341 return res;
2342 }
2343
2344 /** Visitor method: Translate list of trees.
2345 */
2346 public <T extends JCExpression> List<T> translate(List<T> trees, Type type) {
2347 if (trees == null) return null;
2348 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
2349 l.head = translate(l.head, type);
2350 return trees;
2351 }
2352
2353 public void visitPackageDef(JCPackageDecl tree) {
2354 if (!needPackageInfoClass(tree))
2355 return;
2356
2357 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2358 // package-info is marked SYNTHETIC in JDK 1.6 and later releases
2359 flags = flags | Flags.SYNTHETIC;
2360 ClassSymbol c = tree.packge.package_info;
2361 c.setAttributes(tree.packge);
2362 c.flags_field |= flags;
2363 ClassType ctype = (ClassType) c.type;
2364 ctype.supertype_field = syms.objectType;
2365 ctype.interfaces_field = List.nil();
2366 createInfoClass(tree.annotations, c);
2367 }
2368 // where
2369 private boolean needPackageInfoClass(JCPackageDecl pd) {
2370 switch (pkginfoOpt) {
2371 case ALWAYS:
2372 return true;
2373 case LEGACY:
2374 return pd.getAnnotations().nonEmpty();
2375 case NONEMPTY:
2376 for (Attribute.Compound a :
2377 pd.packge.getDeclarationAttributes()) {
2378 Attribute.RetentionPolicy p = types.getRetention(a);
2379 if (p != Attribute.RetentionPolicy.SOURCE)
2380 return true;
2381 }
2382 return false;
2383 }
2384 throw new AssertionError();
2385 }
2386
2387 public void visitModuleDef(JCModuleDecl tree) {
2388 ModuleSymbol msym = tree.sym;
2389 ClassSymbol c = msym.module_info;
2390 c.flags_field |= Flags.MODULE;
2391 createInfoClass(List.<JCAnnotation>nil(), tree.sym.module_info);
2392 }
2393
2394 private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) {
2395 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2396 JCClassDecl infoClass =
2397 make.ClassDef(make.Modifiers(flags, annots),
2398 c.name, List.<JCTypeParameter>nil(),
2399 null, List.<JCExpression>nil(), List.<JCTree>nil());
2400 infoClass.sym = c;
2401 translated.append(infoClass);
2402 }
2403
2404 public void visitClassDef(JCClassDecl tree) {
2405 Env<AttrContext> prevEnv = attrEnv;
2406 ClassSymbol currentClassPrev = currentClass;
2407 MethodSymbol currentMethodSymPrev = currentMethodSym;
2408
2409 currentClass = tree.sym;
2410 currentMethodSym = null;
2411 attrEnv = typeEnvs.remove(currentClass);
2412 if (attrEnv == null)
2413 attrEnv = prevEnv;
2414
2415 classdefs.put(currentClass, tree);
2416
2417 proxies = proxies.dup(currentClass);
2418 List<VarSymbol> prevOuterThisStack = outerThisStack;
2419
2420 // If this is an enum definition
2421 if ((tree.mods.flags & ENUM) != 0 &&
2422 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0)
2423 visitEnumDef(tree);
2424
2425 // If this is a nested class, define a this$n field for
2426 // it and add to proxies.
2427 JCVariableDecl otdef = null;
2428 if (currentClass.hasOuterInstance())
2429 otdef = outerThisDef(tree.pos, currentClass);
2430
2431 // If this is a local class, define proxies for all its free variables.
2432 List<JCVariableDecl> fvdefs = freevarDefs(
2433 tree.pos, freevars(currentClass), currentClass);
2434
2435 // Recursively translate superclass, interfaces.
2436 tree.extending = translate(tree.extending);
2437 tree.implementing = translate(tree.implementing);
2438
2439 if (currentClass.isLocal()) {
2440 ClassSymbol encl = currentClass.owner.enclClass();
2441 if (encl.trans_local == null) {
2442 encl.trans_local = List.nil();
2443 }
2444 encl.trans_local = encl.trans_local.prepend(currentClass);
2445 }
2446
2447 // Recursively translate members, taking into account that new members
2448 // might be created during the translation and prepended to the member
2449 // list `tree.defs'.
2450 List<JCTree> seen = List.nil();
2451 while (tree.defs != seen) {
2452 List<JCTree> unseen = tree.defs;
2453 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) {
2454 JCTree outermostMemberDefPrev = outermostMemberDef;
2455 if (outermostMemberDefPrev == null) outermostMemberDef = l.head;
2456 l.head = translate(l.head);
2457 outermostMemberDef = outermostMemberDefPrev;
2458 }
2459 seen = unseen;
2460 }
2461
2462 // Convert a protected modifier to public, mask static modifier.
2463 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC;
2464 tree.mods.flags &= ClassFlags;
2465
2466 // Convert name to flat representation, replacing '.' by '$'.
2467 tree.name = Convert.shortName(currentClass.flatName());
2468
2469 // Add this$n and free variables proxy definitions to class.
2470
2471 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) {
2472 tree.defs = tree.defs.prepend(l.head);
2473 enterSynthetic(tree.pos(), l.head.sym, currentClass.members());
2474 }
2475 if (currentClass.hasOuterInstance()) {
2476 tree.defs = tree.defs.prepend(otdef);
2477 enterSynthetic(tree.pos(), otdef.sym, currentClass.members());
2478 }
2479
2480 proxies = proxies.leave();
2481 outerThisStack = prevOuterThisStack;
2482
2483 // Append translated tree to `translated' queue.
2484 translated.append(tree);
2485
2486 attrEnv = prevEnv;
2487 currentClass = currentClassPrev;
2488 currentMethodSym = currentMethodSymPrev;
2489
2490 // Return empty block {} as a placeholder for an inner class.
2491 result = make_at(tree.pos()).Block(SYNTHETIC, List.<JCStatement>nil());
2492 }
2493
2494 /** Translate an enum class. */
2495 private void visitEnumDef(JCClassDecl tree) {
2496 make_at(tree.pos());
2497
2498 // add the supertype, if needed
2499 if (tree.extending == null)
2500 tree.extending = make.Type(types.supertype(tree.type));
2501
2502 // classOfType adds a cache field to tree.defs
2503 JCExpression e_class = classOfType(tree.sym.type, tree.pos()).
2504 setType(types.erasure(syms.classType));
2505
2506 // process each enumeration constant, adding implicit constructor parameters
2507 int nextOrdinal = 0;
2508 ListBuffer<JCExpression> values = new ListBuffer<>();
2509 ListBuffer<JCTree> enumDefs = new ListBuffer<>();
2510 ListBuffer<JCTree> otherDefs = new ListBuffer<>();
2511 for (List<JCTree> defs = tree.defs;
2512 defs.nonEmpty();
2513 defs=defs.tail) {
2514 if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
2515 JCVariableDecl var = (JCVariableDecl)defs.head;
2516 visitEnumConstantDef(var, nextOrdinal++);
2517 values.append(make.QualIdent(var.sym));
2518 enumDefs.append(var);
2519 } else {
2520 otherDefs.append(defs.head);
2521 }
2522 }
2523
2524 // private static final T[] #VALUES = { a, b, c };
2525 Name valuesName = names.fromString(target.syntheticNameChar() + "VALUES");
2526 while (tree.sym.members().findFirst(valuesName) != null) // avoid name clash
2527 valuesName = names.fromString(valuesName + "" + target.syntheticNameChar());
2528 Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass);
2529 VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC,
2530 valuesName,
2531 arrayType,
2532 tree.type.tsym);
2533 JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)),
2534 List.<JCExpression>nil(),
2535 values.toList());
2536 newArray.type = arrayType;
2537 enumDefs.append(make.VarDef(valuesVar, newArray));
2538 tree.sym.members().enter(valuesVar);
2539
2540 Symbol valuesSym = lookupMethod(tree.pos(), names.values,
2541 tree.type, List.<Type>nil());
2542 List<JCStatement> valuesBody;
2543 if (useClone()) {
2544 // return (T[]) $VALUES.clone();
2545 JCTypeCast valuesResult =
2546 make.TypeCast(valuesSym.type.getReturnType(),
2547 make.App(make.Select(make.Ident(valuesVar),
2548 syms.arrayCloneMethod)));
2549 valuesBody = List.<JCStatement>of(make.Return(valuesResult));
2550 } else {
2551 // template: T[] $result = new T[$values.length];
2552 Name resultName = names.fromString(target.syntheticNameChar() + "result");
2553 while (tree.sym.members().findFirst(resultName) != null) // avoid name clash
2554 resultName = names.fromString(resultName + "" + target.syntheticNameChar());
2555 VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC,
2556 resultName,
2557 arrayType,
2558 valuesSym);
2559 JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)),
2560 List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)),
2561 null);
2562 resultArray.type = arrayType;
2563 JCVariableDecl decl = make.VarDef(resultVar, resultArray);
2564
2565 // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length);
2566 if (systemArraycopyMethod == null) {
2567 systemArraycopyMethod =
2568 new MethodSymbol(PUBLIC | STATIC,
2569 names.fromString("arraycopy"),
2570 new MethodType(List.<Type>of(syms.objectType,
2571 syms.intType,
2572 syms.objectType,
2573 syms.intType,
2574 syms.intType),
2575 syms.voidType,
2576 List.<Type>nil(),
2577 syms.methodClass),
2578 syms.systemType.tsym);
2579 }
2580 JCStatement copy =
2581 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym),
2582 systemArraycopyMethod),
2583 List.of(make.Ident(valuesVar), make.Literal(0),
2584 make.Ident(resultVar), make.Literal(0),
2585 make.Select(make.Ident(valuesVar), syms.lengthVar))));
2586
2587 // template: return $result;
2588 JCStatement ret = make.Return(make.Ident(resultVar));
2589 valuesBody = List.<JCStatement>of(decl, copy, ret);
2590 }
2591
2592 JCMethodDecl valuesDef =
2593 make.MethodDef((MethodSymbol)valuesSym, make.Block(0, valuesBody));
2594
2595 enumDefs.append(valuesDef);
2596
2597 if (debugLower)
2598 System.err.println(tree.sym + ".valuesDef = " + valuesDef);
2599
2600 /** The template for the following code is:
2601 *
2602 * public static E valueOf(String name) {
2603 * return (E)Enum.valueOf(E.class, name);
2604 * }
2605 *
2606 * where E is tree.sym
2607 */
2608 MethodSymbol valueOfSym = lookupMethod(tree.pos(),
2609 names.valueOf,
2610 tree.sym.type,
2611 List.of(syms.stringType));
2612 Assert.check((valueOfSym.flags() & STATIC) != 0);
2613 VarSymbol nameArgSym = valueOfSym.params.head;
2614 JCIdent nameVal = make.Ident(nameArgSym);
2615 JCStatement enum_ValueOf =
2616 make.Return(make.TypeCast(tree.sym.type,
2617 makeCall(make.Ident(syms.enumSym),
2618 names.valueOf,
2619 List.of(e_class, nameVal))));
2620 JCMethodDecl valueOf = make.MethodDef(valueOfSym,
2621 make.Block(0, List.of(enum_ValueOf)));
2622 nameVal.sym = valueOf.params.head.sym;
2623 if (debugLower)
2624 System.err.println(tree.sym + ".valueOf = " + valueOf);
2625 enumDefs.append(valueOf);
2626
2627 enumDefs.appendList(otherDefs.toList());
2628 tree.defs = enumDefs.toList();
2629 }
2630 // where
2631 private MethodSymbol systemArraycopyMethod;
2632 private boolean useClone() {
2633 try {
2634 return syms.objectType.tsym.members().findFirst(names.clone) != null;
2635 }
2636 catch (CompletionFailure e) {
2637 return false;
2638 }
2639 }
2640
2641 /** Translate an enumeration constant and its initializer. */
2642 private void visitEnumConstantDef(JCVariableDecl var, int ordinal) {
2643 JCNewClass varDef = (JCNewClass)var.init;
2644 varDef.args = varDef.args.
2645 prepend(makeLit(syms.intType, ordinal)).
2646 prepend(makeLit(syms.stringType, var.name.toString()));
2647 }
2648
2649 public void visitMethodDef(JCMethodDecl tree) {
2650 if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) {
2651 // Add "String $enum$name, int $enum$ordinal" to the beginning of the
2652 // argument list for each constructor of an enum.
2653 JCVariableDecl nameParam = make_at(tree.pos()).
2654 Param(names.fromString(target.syntheticNameChar() +
2655 "enum" + target.syntheticNameChar() + "name"),
2656 syms.stringType, tree.sym);
2657 nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC;
2658 JCVariableDecl ordParam = make.
2659 Param(names.fromString(target.syntheticNameChar() +
2660 "enum" + target.syntheticNameChar() +
2661 "ordinal"),
2662 syms.intType, tree.sym);
2663 ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC;
2664
2665 MethodSymbol m = tree.sym;
2666 tree.params = tree.params.prepend(ordParam).prepend(nameParam);
2667
2668 m.extraParams = m.extraParams.prepend(ordParam.sym);
2669 m.extraParams = m.extraParams.prepend(nameParam.sym);
2670 Type olderasure = m.erasure(types);
2671 m.erasure_field = new MethodType(
2672 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType),
2673 olderasure.getReturnType(),
2674 olderasure.getThrownTypes(),
2675 syms.methodClass);
2676 }
2677
2678 JCMethodDecl prevMethodDef = currentMethodDef;
2679 MethodSymbol prevMethodSym = currentMethodSym;
2680 try {
2681 currentMethodDef = tree;
2682 currentMethodSym = tree.sym;
2683 visitMethodDefInternal(tree);
2684 } finally {
2685 currentMethodDef = prevMethodDef;
2686 currentMethodSym = prevMethodSym;
2687 }
2688 }
2689
2690 private void visitMethodDefInternal(JCMethodDecl tree) {
2691 if (tree.name == names.init &&
2692 (currentClass.isInner() || currentClass.isLocal())) {
2693 // We are seeing a constructor of an inner class.
2694 MethodSymbol m = tree.sym;
2695
2696 // Push a new proxy scope for constructor parameters.
2697 // and create definitions for any this$n and proxy parameters.
2698 proxies = proxies.dup(m);
2699 List<VarSymbol> prevOuterThisStack = outerThisStack;
2700 List<VarSymbol> fvs = freevars(currentClass);
2701 JCVariableDecl otdef = null;
2702 if (currentClass.hasOuterInstance())
2703 otdef = outerThisDef(tree.pos, m);
2704 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER);
2705
2706 // Recursively translate result type, parameters and thrown list.
2707 tree.restype = translate(tree.restype);
2708 tree.params = translateVarDefs(tree.params);
2709 tree.thrown = translate(tree.thrown);
2710
2711 // when compiling stubs, don't process body
2712 if (tree.body == null) {
2713 result = tree;
2714 return;
2715 }
2716
2717 // Add this$n (if needed) in front of and free variables behind
2718 // constructor parameter list.
2719 tree.params = tree.params.appendList(fvdefs);
2720 if (currentClass.hasOuterInstance()) {
2721 tree.params = tree.params.prepend(otdef);
2722 }
2723
2724 // If this is an initial constructor, i.e., it does not start with
2725 // this(...), insert initializers for this$n and proxies
2726 // before (pre-1.4, after) the call to superclass constructor.
2727 JCStatement selfCall = translate(tree.body.stats.head);
2728
2729 List<JCStatement> added = List.nil();
2730 if (fvs.nonEmpty()) {
2731 List<Type> addedargtypes = List.nil();
2732 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
2733 final Name pName = proxyName(l.head.name);
2734 m.capturedLocals =
2735 m.capturedLocals.prepend((VarSymbol)
2736 (proxies.findFirst(pName)));
2737 if (TreeInfo.isInitialConstructor(tree)) {
2738 added = added.prepend(
2739 initField(tree.body.pos, pName));
2740 }
2741 addedargtypes = addedargtypes.prepend(l.head.erasure(types));
2742 }
2743 Type olderasure = m.erasure(types);
2744 m.erasure_field = new MethodType(
2745 olderasure.getParameterTypes().appendList(addedargtypes),
2746 olderasure.getReturnType(),
2747 olderasure.getThrownTypes(),
2748 syms.methodClass);
2749 }
2750 if (currentClass.hasOuterInstance() &&
2751 TreeInfo.isInitialConstructor(tree))
2752 {
2753 added = added.prepend(initOuterThis(tree.body.pos));
2754 }
2755
2756 // pop local variables from proxy stack
2757 proxies = proxies.leave();
2758
2759 // recursively translate following local statements and
2760 // combine with this- or super-call
2761 List<JCStatement> stats = translate(tree.body.stats.tail);
2762 tree.body.stats = stats.prepend(selfCall).prependList(added);
2763 outerThisStack = prevOuterThisStack;
2764 } else {
2765 Map<Symbol, Symbol> prevLambdaTranslationMap =
2766 lambdaTranslationMap;
2767 try {
2768 lambdaTranslationMap = (tree.sym.flags() & SYNTHETIC) != 0 &&
2769 tree.sym.name.startsWith(names.lambda) ?
2770 makeTranslationMap(tree) : null;
2771 super.visitMethodDef(tree);
2772 } finally {
2773 lambdaTranslationMap = prevLambdaTranslationMap;
2774 }
2775 }
2776 result = tree;
2777 }
2778 //where
2779 private Map<Symbol, Symbol> makeTranslationMap(JCMethodDecl tree) {
2780 Map<Symbol, Symbol> translationMap = new HashMap<>();
2781 for (JCVariableDecl vd : tree.params) {
2782 Symbol p = vd.sym;
2783 if (p != p.baseSymbol()) {
2784 translationMap.put(p.baseSymbol(), p);
2785 }
2786 }
2787 return translationMap;
2788 }
2789
2790 public void visitTypeCast(JCTypeCast tree) {
2791 tree.clazz = translate(tree.clazz);
2792 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive())
2793 tree.expr = translate(tree.expr, tree.type);
2794 else
2795 tree.expr = translate(tree.expr);
2796 result = tree;
2797 }
2798
2799 public void visitNewClass(JCNewClass tree) {
2800 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
2801
2802 // Box arguments, if necessary
2803 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0;
2804 List<Type> argTypes = tree.constructor.type.getParameterTypes();
2805 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType);
2806 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement);
2807 tree.varargsElement = null;
2808
2809 // If created class is local, add free variables after
2810 // explicit constructor arguments.
2811 if (c.isLocal()) {
2812 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
2813 }
2814
2815 // If an access constructor is used, append null as a last argument.
2816 Symbol constructor = accessConstructor(tree.pos(), tree.constructor);
2817 if (constructor != tree.constructor) {
2818 tree.args = tree.args.append(makeNull());
2819 tree.constructor = constructor;
2820 }
2821
2822 // If created class has an outer instance, and new is qualified, pass
2823 // qualifier as first argument. If new is not qualified, pass the
2824 // correct outer instance as first argument.
2825 if (c.hasOuterInstance()) {
2826 JCExpression thisArg;
2827 if (tree.encl != null) {
2828 thisArg = attr.makeNullCheck(translate(tree.encl));
2829 thisArg.type = tree.encl.type;
2830 } else if (c.isLocal()) {
2831 // local class
2832 thisArg = makeThis(tree.pos(), c.type.getEnclosingType().tsym);
2833 } else {
2834 // nested class
2835 thisArg = makeOwnerThis(tree.pos(), c, false);
2836 }
2837 tree.args = tree.args.prepend(thisArg);
2838 }
2839 tree.encl = null;
2840
2841 // If we have an anonymous class, create its flat version, rather
2842 // than the class or interface following new.
2843 if (tree.def != null) {
2844 translate(tree.def);
2845 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym));
2846 tree.def = null;
2847 } else {
2848 tree.clazz = access(c, tree.clazz, enclOp, false);
2849 }
2850 result = tree;
2851 }
2852
2853 // Simplify conditionals with known constant controlling expressions.
2854 // This allows us to avoid generating supporting declarations for
2855 // the dead code, which will not be eliminated during code generation.
2856 // Note that Flow.isFalse and Flow.isTrue only return true
2857 // for constant expressions in the sense of JLS 15.27, which
2858 // are guaranteed to have no side-effects. More aggressive
2859 // constant propagation would require that we take care to
2860 // preserve possible side-effects in the condition expression.
2861
2862 // One common case is equality expressions involving a constant and null.
2863 // Since null is not a constant expression (because null cannot be
2864 // represented in the constant pool), equality checks involving null are
2865 // not captured by Flow.isTrue/isFalse.
2866 // Equality checks involving a constant and null, e.g.
2867 // "" == null
2868 // are safe to simplify as no side-effects can occur.
2869
2870 private boolean isTrue(JCTree exp) {
2871 if (exp.type.isTrue())
2872 return true;
2873 Boolean b = expValue(exp);
2874 return b == null ? false : b;
2875 }
2876 private boolean isFalse(JCTree exp) {
2877 if (exp.type.isFalse())
2878 return true;
2879 Boolean b = expValue(exp);
2880 return b == null ? false : !b;
2881 }
2882 /* look for (in)equality relations involving null.
2883 * return true - if expression is always true
2884 * false - if expression is always false
2885 * null - if expression cannot be eliminated
2886 */
2887 private Boolean expValue(JCTree exp) {
2888 while (exp.hasTag(PARENS))
2889 exp = ((JCParens)exp).expr;
2890
2891 boolean eq;
2892 switch (exp.getTag()) {
2893 case EQ: eq = true; break;
2894 case NE: eq = false; break;
2895 default:
2896 return null;
2897 }
2898
2899 // we have a JCBinary(EQ|NE)
2900 // check if we have two literals (constants or null)
2901 JCBinary b = (JCBinary)exp;
2902 if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs);
2903 if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs);
2904 return null;
2905 }
2906 private Boolean expValueIsNull(boolean eq, JCTree t) {
2907 if (t.type.hasTag(BOT)) return Boolean.valueOf(eq);
2908 if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq);
2909 return null;
2910 }
2911
2912 /** Visitor method for conditional expressions.
2913 */
2914 @Override
2915 public void visitConditional(JCConditional tree) {
2916 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
2917 if (isTrue(cond)) {
2918 result = convert(translate(tree.truepart, tree.type), tree.type);
2919 addPrunedInfo(cond);
2920 } else if (isFalse(cond)) {
2921 result = convert(translate(tree.falsepart, tree.type), tree.type);
2922 addPrunedInfo(cond);
2923 } else {
2924 // Condition is not a compile-time constant.
2925 tree.truepart = translate(tree.truepart, tree.type);
2926 tree.falsepart = translate(tree.falsepart, tree.type);
2927 result = tree;
2928 }
2929 }
2930 //where
2931 private JCExpression convert(JCExpression tree, Type pt) {
2932 if (tree.type == pt || tree.type.hasTag(BOT))
2933 return tree;
2934 JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree);
2935 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt)
2936 : pt;
2937 return result;
2938 }
2939
2940 /** Visitor method for if statements.
2941 */
2942 public void visitIf(JCIf tree) {
2943 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
2944 if (isTrue(cond)) {
2945 result = translate(tree.thenpart);
2946 addPrunedInfo(cond);
2947 } else if (isFalse(cond)) {
2948 if (tree.elsepart != null) {
2949 result = translate(tree.elsepart);
2950 } else {
2951 result = make.Skip();
2952 }
2953 addPrunedInfo(cond);
2954 } else {
2955 // Condition is not a compile-time constant.
2956 tree.thenpart = translate(tree.thenpart);
2957 tree.elsepart = translate(tree.elsepart);
2958 result = tree;
2959 }
2960 }
2961
2962 /** Visitor method for assert statements. Translate them away.
2963 */
2964 public void visitAssert(JCAssert tree) {
2965 DiagnosticPosition detailPos = (tree.detail == null) ? tree.pos() : tree.detail.pos();
2966 tree.cond = translate(tree.cond, syms.booleanType);
2967 if (!tree.cond.type.isTrue()) {
2968 JCExpression cond = assertFlagTest(tree.pos());
2969 List<JCExpression> exnArgs = (tree.detail == null) ?
2970 List.<JCExpression>nil() : List.of(translate(tree.detail));
2971 if (!tree.cond.type.isFalse()) {
2972 cond = makeBinary
2973 (AND,
2974 cond,
2975 makeUnary(NOT, tree.cond));
2976 }
2977 result =
2978 make.If(cond,
2979 make_at(tree).
2980 Throw(makeNewClass(syms.assertionErrorType, exnArgs)),
2981 null);
2982 } else {
2983 result = make.Skip();
2984 }
2985 }
2986
2987 public void visitApply(JCMethodInvocation tree) {
2988 Symbol meth = TreeInfo.symbol(tree.meth);
2989 List<Type> argtypes = meth.type.getParameterTypes();
2990 if (meth.name == names.init && meth.owner == syms.enumSym)
2991 argtypes = argtypes.tail.tail;
2992 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement);
2993 tree.varargsElement = null;
2994 Name methName = TreeInfo.name(tree.meth);
2995 if (meth.name==names.init) {
2996 // We are seeing a this(...) or super(...) constructor call.
2997 // If an access constructor is used, append null as a last argument.
2998 Symbol constructor = accessConstructor(tree.pos(), meth);
2999 if (constructor != meth) {
3000 tree.args = tree.args.append(makeNull());
3001 TreeInfo.setSymbol(tree.meth, constructor);
3002 }
3003
3004 // If we are calling a constructor of a local class, add
3005 // free variables after explicit constructor arguments.
3006 ClassSymbol c = (ClassSymbol)constructor.owner;
3007 if (c.isLocal()) {
3008 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
3009 }
3010
3011 // If we are calling a constructor of an enum class, pass
3012 // along the name and ordinal arguments
3013 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) {
3014 List<JCVariableDecl> params = currentMethodDef.params;
3015 if (currentMethodSym.owner.hasOuterInstance())
3016 params = params.tail; // drop this$n
3017 tree.args = tree.args
3018 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal
3019 .prepend(make.Ident(params.head.sym)); // name
3020 }
3021
3022 // If we are calling a constructor of a class with an outer
3023 // instance, and the call
3024 // is qualified, pass qualifier as first argument in front of
3025 // the explicit constructor arguments. If the call
3026 // is not qualified, pass the correct outer instance as
3027 // first argument.
3028 if (c.hasOuterInstance()) {
3029 JCExpression thisArg;
3030 if (tree.meth.hasTag(SELECT)) {
3031 thisArg = attr.
3032 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected));
3033 tree.meth = make.Ident(constructor);
3034 ((JCIdent) tree.meth).name = methName;
3035 } else if (c.isLocal() || methName == names._this){
3036 // local class or this() call
3037 thisArg = makeThis(tree.meth.pos(), c.type.getEnclosingType().tsym);
3038 } else {
3039 // super() call of nested class - never pick 'this'
3040 thisArg = makeOwnerThisN(tree.meth.pos(), c, false);
3041 }
3042 tree.args = tree.args.prepend(thisArg);
3043 }
3044 } else {
3045 // We are seeing a normal method invocation; translate this as usual.
3046 tree.meth = translate(tree.meth);
3047
3048 // If the translated method itself is an Apply tree, we are
3049 // seeing an access method invocation. In this case, append
3050 // the method arguments to the arguments of the access method.
3051 if (tree.meth.hasTag(APPLY)) {
3052 JCMethodInvocation app = (JCMethodInvocation)tree.meth;
3053 app.args = tree.args.prependList(app.args);
3054 result = app;
3055 return;
3056 }
3057 }
3058 result = tree;
3059 }
3060
3061 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) {
3062 List<JCExpression> args = _args;
3063 if (parameters.isEmpty()) return args;
3064 boolean anyChanges = false;
3065 ListBuffer<JCExpression> result = new ListBuffer<>();
3066 while (parameters.tail.nonEmpty()) {
3067 JCExpression arg = translate(args.head, parameters.head);
3068 anyChanges |= (arg != args.head);
3069 result.append(arg);
3070 args = args.tail;
3071 parameters = parameters.tail;
3072 }
3073 Type parameter = parameters.head;
3074 if (varargsElement != null) {
3075 anyChanges = true;
3076 ListBuffer<JCExpression> elems = new ListBuffer<>();
3077 while (args.nonEmpty()) {
3078 JCExpression arg = translate(args.head, varargsElement);
3079 elems.append(arg);
3080 args = args.tail;
3081 }
3082 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement),
3083 List.<JCExpression>nil(),
3084 elems.toList());
3085 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass);
3086 result.append(boxedArgs);
3087 } else {
3088 if (args.length() != 1) throw new AssertionError(args);
3089 JCExpression arg = translate(args.head, parameter);
3090 anyChanges |= (arg != args.head);
3091 result.append(arg);
3092 if (!anyChanges) return _args;
3093 }
3094 return result.toList();
3095 }
3096
3097 /** Expand a boxing or unboxing conversion if needed. */
3098 @SuppressWarnings("unchecked") // XXX unchecked
3099 <T extends JCExpression> T boxIfNeeded(T tree, Type type) {
3100 boolean havePrimitive = tree.type.isPrimitive();
3101 if (havePrimitive == type.isPrimitive())
3102 return tree;
3103 if (havePrimitive) {
3104 Type unboxedTarget = types.unboxedType(type);
3105 if (!unboxedTarget.hasTag(NONE)) {
3106 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89;
3107 tree.type = unboxedTarget.constType(tree.type.constValue());
3108 return (T)boxPrimitive(tree, types.erasure(type));
3109 } else {
3110 tree = (T)boxPrimitive(tree);
3111 }
3112 } else {
3113 tree = (T)unbox(tree, type);
3114 }
3115 return tree;
3116 }
3117
3118 /** Box up a single primitive expression. */
3119 JCExpression boxPrimitive(JCExpression tree) {
3120 return boxPrimitive(tree, types.boxedClass(tree.type).type);
3121 }
3122
3123 /** Box up a single primitive expression. */
3124 JCExpression boxPrimitive(JCExpression tree, Type box) {
3125 make_at(tree.pos());
3126 Symbol valueOfSym = lookupMethod(tree.pos(),
3127 names.valueOf,
3128 box,
3129 List.<Type>nil()
3130 .prepend(tree.type));
3131 return make.App(make.QualIdent(valueOfSym), List.of(tree));
3132 }
3133
3134 /** Unbox an object to a primitive value. */
3135 JCExpression unbox(JCExpression tree, Type primitive) {
3136 Type unboxedType = types.unboxedType(tree.type);
3137 if (unboxedType.hasTag(NONE)) {
3138 unboxedType = primitive;
3139 if (!unboxedType.isPrimitive())
3140 throw new AssertionError(unboxedType);
3141 make_at(tree.pos());
3142 tree = make.TypeCast(types.boxedClass(unboxedType).type, tree);
3143 } else {
3144 // There must be a conversion from unboxedType to primitive.
3145 if (!types.isSubtype(unboxedType, primitive))
3146 throw new AssertionError(tree);
3147 }
3148 make_at(tree.pos());
3149 Symbol valueSym = lookupMethod(tree.pos(),
3150 unboxedType.tsym.name.append(names.Value), // x.intValue()
3151 tree.type,
3152 List.<Type>nil());
3153 return make.App(make.Select(tree, valueSym));
3154 }
3155
3156 /** Visitor method for parenthesized expressions.
3157 * If the subexpression has changed, omit the parens.
3158 */
3159 public void visitParens(JCParens tree) {
3160 JCTree expr = translate(tree.expr);
3161 result = ((expr == tree.expr) ? tree : expr);
3162 }
3163
3164 public void visitIndexed(JCArrayAccess tree) {
3165 tree.indexed = translate(tree.indexed);
3166 tree.index = translate(tree.index, syms.intType);
3167 result = tree;
3168 }
3169
3170 public void visitAssign(JCAssign tree) {
3171 tree.lhs = translate(tree.lhs, tree);
3172 tree.rhs = translate(tree.rhs, tree.lhs.type);
3173
3174 // If translated left hand side is an Apply, we are
3175 // seeing an access method invocation. In this case, append
3176 // right hand side as last argument of the access method.
3177 if (tree.lhs.hasTag(APPLY)) {
3178 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3179 app.args = List.of(tree.rhs).prependList(app.args);
3180 result = app;
3181 } else {
3182 result = tree;
3183 }
3184 }
3185
3186 public void visitAssignop(final JCAssignOp tree) {
3187 final boolean boxingReq = !tree.lhs.type.isPrimitive() &&
3188 tree.operator.type.getReturnType().isPrimitive();
3189
3190 AssignopDependencyScanner depScanner = new AssignopDependencyScanner(tree);
3191 depScanner.scan(tree.rhs);
3192
3193 if (boxingReq || depScanner.dependencyFound) {
3194 // boxing required; need to rewrite as x = (unbox typeof x)(x op y);
3195 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y)
3196 // (but without recomputing x)
3197 JCTree newTree = abstractLval(tree.lhs, new TreeBuilder() {
3198 public JCExpression build(final JCExpression lhs) {
3199 JCTree.Tag newTag = tree.getTag().noAssignOp();
3200 // Erasure (TransTypes) can change the type of
3201 // tree.lhs. However, we can still get the
3202 // unerased type of tree.lhs as it is stored
3203 // in tree.type in Attr.
3204 OperatorSymbol newOperator = operators.resolveBinary(tree,
3205 newTag,
3206 tree.type,
3207 tree.rhs.type);
3208 JCExpression expr = (JCExpression) lhs.clone();
3209 if (expr.type != tree.type)
3210 expr = make.TypeCast(tree.type, expr);
3211 JCBinary opResult = make.Binary(newTag, expr, tree.rhs);
3212 opResult.operator = newOperator;
3213 opResult.type = newOperator.type.getReturnType();
3214 JCExpression newRhs = boxingReq ?
3215 make.TypeCast(types.unboxedType(tree.type), opResult) :
3216 opResult;
3217 return make.Assign(lhs, newRhs).setType(tree.type);
3218 }
3219 });
3220 result = translate(newTree);
3221 return;
3222 }
3223 tree.lhs = translate(tree.lhs, tree);
3224 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
3225
3226 // If translated left hand side is an Apply, we are
3227 // seeing an access method invocation. In this case, append
3228 // right hand side as last argument of the access method.
3229 if (tree.lhs.hasTag(APPLY)) {
3230 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3231 // if operation is a += on strings,
3232 // make sure to convert argument to string
3233 JCExpression rhs = tree.operator.opcode == string_add
3234 ? makeString(tree.rhs)
3235 : tree.rhs;
3236 app.args = List.of(rhs).prependList(app.args);
3237 result = app;
3238 } else {
3239 result = tree;
3240 }
3241 }
3242
3243 class AssignopDependencyScanner extends TreeScanner {
3244
3245 Symbol sym;
3246 boolean dependencyFound = false;
3247
3248 AssignopDependencyScanner(JCAssignOp tree) {
3249 this.sym = TreeInfo.symbol(tree.lhs);
3250 }
3251
3252 @Override
3253 public void scan(JCTree tree) {
3254 if (tree != null && sym != null) {
3255 tree.accept(this);
3256 }
3257 }
3258
3259 @Override
3260 public void visitAssignop(JCAssignOp tree) {
3261 if (TreeInfo.symbol(tree.lhs) == sym) {
3262 dependencyFound = true;
3263 return;
3264 }
3265 super.visitAssignop(tree);
3266 }
3267
3268 @Override
3269 public void visitUnary(JCUnary tree) {
3270 if (TreeInfo.symbol(tree.arg) == sym) {
3271 dependencyFound = true;
3272 return;
3273 }
3274 super.visitUnary(tree);
3275 }
3276 }
3277
3278 /** Lower a tree of the form e++ or e-- where e is an object type */
3279 JCExpression lowerBoxedPostop(final JCUnary tree) {
3280 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2
3281 // or
3282 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2
3283 // where OP is += or -=
3284 final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST);
3285 return abstractLval(tree.arg, new TreeBuilder() {
3286 public JCExpression build(final JCExpression tmp1) {
3287 return abstractRval(tmp1, tree.arg.type, new TreeBuilder() {
3288 public JCExpression build(final JCExpression tmp2) {
3289 JCTree.Tag opcode = (tree.hasTag(POSTINC))
3290 ? PLUS_ASG : MINUS_ASG;
3291 JCExpression lhs = (JCExpression)tmp1.clone();
3292 lhs = cast
3293 ? make.TypeCast(tree.arg.type, lhs)
3294 : lhs;
3295 JCExpression update = makeAssignop(opcode,
3296 lhs,
3297 make.Literal(1));
3298 return makeComma(update, tmp2);
3299 }
3300 });
3301 }
3302 });
3303 }
3304
3305 public void visitUnary(JCUnary tree) {
3306 boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp();
3307 if (isUpdateOperator && !tree.arg.type.isPrimitive()) {
3308 switch(tree.getTag()) {
3309 case PREINC: // ++ e
3310 // translate to e += 1
3311 case PREDEC: // -- e
3312 // translate to e -= 1
3313 {
3314 JCTree.Tag opcode = (tree.hasTag(PREINC))
3315 ? PLUS_ASG : MINUS_ASG;
3316 JCAssignOp newTree = makeAssignop(opcode,
3317 tree.arg,
3318 make.Literal(1));
3319 result = translate(newTree, tree.type);
3320 return;
3321 }
3322 case POSTINC: // e ++
3323 case POSTDEC: // e --
3324 {
3325 result = translate(lowerBoxedPostop(tree), tree.type);
3326 return;
3327 }
3328 }
3329 throw new AssertionError(tree);
3330 }
3331
3332 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type);
3333
3334 if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) {
3335 tree.type = cfolder.fold1(bool_not, tree.arg.type);
3336 }
3337
3338 // If translated left hand side is an Apply, we are
3339 // seeing an access method invocation. In this case, return
3340 // that access method invocation as result.
3341 if (isUpdateOperator && tree.arg.hasTag(APPLY)) {
3342 result = tree.arg;
3343 } else {
3344 result = tree;
3345 }
3346 }
3347
3348 public void visitBinary(JCBinary tree) {
3349 List<Type> formals = tree.operator.type.getParameterTypes();
3350 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head);
3351 switch (tree.getTag()) {
3352 case OR:
3353 if (isTrue(lhs)) {
3354 result = lhs;
3355 return;
3356 }
3357 if (isFalse(lhs)) {
3358 result = translate(tree.rhs, formals.tail.head);
3359 return;
3360 }
3361 break;
3362 case AND:
3363 if (isFalse(lhs)) {
3364 result = lhs;
3365 return;
3366 }
3367 if (isTrue(lhs)) {
3368 result = translate(tree.rhs, formals.tail.head);
3369 return;
3370 }
3371 break;
3372 }
3373 tree.rhs = translate(tree.rhs, formals.tail.head);
3374 result = tree;
3375 }
3376
3377 public void visitIdent(JCIdent tree) {
3378 result = access(tree.sym, tree, enclOp, false);
3379 }
3380
3381 /** Translate away the foreach loop. */
3382 public void visitForeachLoop(JCEnhancedForLoop tree) {
3383 if (types.elemtype(tree.expr.type) == null)
3384 visitIterableForeachLoop(tree);
3385 else
3386 visitArrayForeachLoop(tree);
3387 }
3388 // where
3389 /**
3390 * A statement of the form
3391 *
3392 * <pre>
3393 * for ( T v : arrayexpr ) stmt;
3394 * </pre>
3395 *
3396 * (where arrayexpr is of an array type) gets translated to
3397 *
3398 * <pre>{@code
3399 * for ( { arraytype #arr = arrayexpr;
3400 * int #len = array.length;
3401 * int #i = 0; };
3402 * #i < #len; i$++ ) {
3403 * T v = arr$[#i];
3404 * stmt;
3405 * }
3406 * }</pre>
3407 *
3408 * where #arr, #len, and #i are freshly named synthetic local variables.
3409 */
3410 private void visitArrayForeachLoop(JCEnhancedForLoop tree) {
3411 make_at(tree.expr.pos());
3412 VarSymbol arraycache = new VarSymbol(SYNTHETIC,
3413 names.fromString("arr" + target.syntheticNameChar()),
3414 tree.expr.type,
3415 currentMethodSym);
3416 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr);
3417 VarSymbol lencache = new VarSymbol(SYNTHETIC,
3418 names.fromString("len" + target.syntheticNameChar()),
3419 syms.intType,
3420 currentMethodSym);
3421 JCStatement lencachedef = make.
3422 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar));
3423 VarSymbol index = new VarSymbol(SYNTHETIC,
3424 names.fromString("i" + target.syntheticNameChar()),
3425 syms.intType,
3426 currentMethodSym);
3427
3428 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0));
3429 indexdef.init.type = indexdef.type = syms.intType.constType(0);
3430
3431 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef);
3432 JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache));
3433
3434 JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index)));
3435
3436 Type elemtype = types.elemtype(tree.expr.type);
3437 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache),
3438 make.Ident(index)).setType(elemtype);
3439 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods,
3440 tree.var.name,
3441 tree.var.vartype,
3442 loopvarinit).setType(tree.var.type);
3443 loopvardef.sym = tree.var.sym;
3444 JCBlock body = make.
3445 Block(0, List.of(loopvardef, tree.body));
3446
3447 result = translate(make.
3448 ForLoop(loopinit,
3449 cond,
3450 List.of(step),
3451 body));
3452 patchTargets(body, tree, result);
3453 }
3454 /** Patch up break and continue targets. */
3455 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) {
3456 class Patcher extends TreeScanner {
3457 public void visitBreak(JCBreak tree) {
3458 if (tree.target == src)
3459 tree.target = dest;
3460 }
3461 public void visitContinue(JCContinue tree) {
3462 if (tree.target == src)
3463 tree.target = dest;
3464 }
3465 public void visitClassDef(JCClassDecl tree) {}
3466 }
3467 new Patcher().scan(body);
3468 }
3469 /**
3470 * A statement of the form
3471 *
3472 * <pre>
3473 * for ( T v : coll ) stmt ;
3474 * </pre>
3475 *
3476 * (where coll implements {@code Iterable<? extends T>}) gets translated to
3477 *
3478 * <pre>{@code
3479 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) {
3480 * T v = (T) #i.next();
3481 * stmt;
3482 * }
3483 * }</pre>
3484 *
3485 * where #i is a freshly named synthetic local variable.
3486 */
3487 private void visitIterableForeachLoop(JCEnhancedForLoop tree) {
3488 make_at(tree.expr.pos());
3489 Type iteratorTarget = syms.objectType;
3490 Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type),
3491 syms.iterableType.tsym);
3492 if (iterableType.getTypeArguments().nonEmpty())
3493 iteratorTarget = types.erasure(iterableType.getTypeArguments().head);
3494 Type eType = types.skipTypeVars(tree.expr.type, false);
3495 tree.expr.type = types.erasure(eType);
3496 if (eType.isCompound())
3497 tree.expr = make.TypeCast(types.erasure(iterableType), tree.expr);
3498 Symbol iterator = lookupMethod(tree.expr.pos(),
3499 names.iterator,
3500 eType,
3501 List.<Type>nil());
3502 VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()),
3503 types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)),
3504 currentMethodSym);
3505
3506 JCStatement init = make.
3507 VarDef(itvar, make.App(make.Select(tree.expr, iterator)
3508 .setType(types.erasure(iterator.type))));
3509
3510 Symbol hasNext = lookupMethod(tree.expr.pos(),
3511 names.hasNext,
3512 itvar.type,
3513 List.<Type>nil());
3514 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext));
3515 Symbol next = lookupMethod(tree.expr.pos(),
3516 names.next,
3517 itvar.type,
3518 List.<Type>nil());
3519 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next));
3520 if (tree.var.type.isPrimitive())
3521 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit);
3522 else
3523 vardefinit = make.TypeCast(tree.var.type, vardefinit);
3524 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods,
3525 tree.var.name,
3526 tree.var.vartype,
3527 vardefinit).setType(tree.var.type);
3528 indexDef.sym = tree.var.sym;
3529 JCBlock body = make.Block(0, List.of(indexDef, tree.body));
3530 body.endpos = TreeInfo.endPos(tree.body);
3531 result = translate(make.
3532 ForLoop(List.of(init),
3533 cond,
3534 List.<JCExpressionStatement>nil(),
3535 body));
3536 patchTargets(body, tree, result);
3537 }
3538
3539 public void visitVarDef(JCVariableDecl tree) {
3540 MethodSymbol oldMethodSym = currentMethodSym;
3541 tree.mods = translate(tree.mods);
3542 tree.vartype = translate(tree.vartype);
3543 if (currentMethodSym == null) {
3544 // A class or instance field initializer.
3545 currentMethodSym =
3546 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK,
3547 names.empty, null,
3548 currentClass);
3549 }
3550 if (tree.init != null) tree.init = translate(tree.init, tree.type);
3551 result = tree;
3552 currentMethodSym = oldMethodSym;
3553 }
3554
3555 public void visitBlock(JCBlock tree) {
3556 MethodSymbol oldMethodSym = currentMethodSym;
3557 if (currentMethodSym == null) {
3558 // Block is a static or instance initializer.
3559 currentMethodSym =
3560 new MethodSymbol(tree.flags | BLOCK,
3561 names.empty, null,
3562 currentClass);
3563 }
3564 super.visitBlock(tree);
3565 currentMethodSym = oldMethodSym;
3566 }
3567
3568 public void visitDoLoop(JCDoWhileLoop tree) {
3569 tree.body = translate(tree.body);
3570 tree.cond = translate(tree.cond, syms.booleanType);
3571 result = tree;
3572 }
3573
3574 public void visitWhileLoop(JCWhileLoop tree) {
3575 tree.cond = translate(tree.cond, syms.booleanType);
3576 tree.body = translate(tree.body);
3577 result = tree;
3578 }
3579
3580 public void visitForLoop(JCForLoop tree) {
3581 tree.init = translate(tree.init);
3582 if (tree.cond != null)
3583 tree.cond = translate(tree.cond, syms.booleanType);
3584 tree.step = translate(tree.step);
3585 tree.body = translate(tree.body);
3586 result = tree;
3587 }
3588
3589 public void visitReturn(JCReturn tree) {
3590 if (tree.expr != null)
3591 tree.expr = translate(tree.expr,
3592 types.erasure(currentMethodDef
3593 .restype.type));
3594 result = tree;
3595 }
3596
3597 public void visitSwitch(JCSwitch tree) {
3598 Type selsuper = types.supertype(tree.selector.type);
3599 boolean enumSwitch = selsuper != null &&
3600 (tree.selector.type.tsym.flags() & ENUM) != 0;
3601 boolean stringSwitch = selsuper != null &&
3602 types.isSameType(tree.selector.type, syms.stringType);
3603 Type target = enumSwitch ? tree.selector.type :
3604 (stringSwitch? syms.stringType : syms.intType);
3605 tree.selector = translate(tree.selector, target);
3606 tree.cases = translateCases(tree.cases);
3607 if (enumSwitch) {
3608 result = visitEnumSwitch(tree);
3609 } else if (stringSwitch) {
3610 result = visitStringSwitch(tree);
3611 } else {
3612 result = tree;
3613 }
3614 }
3615
3616 public JCTree visitEnumSwitch(JCSwitch tree) {
3617 TypeSymbol enumSym = tree.selector.type.tsym;
3618 EnumMapping map = mapForEnum(tree.pos(), enumSym);
3619 make_at(tree.pos());
3620 Symbol ordinalMethod = lookupMethod(tree.pos(),
3621 names.ordinal,
3622 tree.selector.type,
3623 List.<Type>nil());
3624 JCArrayAccess selector = make.Indexed(map.mapVar,
3625 make.App(make.Select(tree.selector,
3626 ordinalMethod)));
3627 ListBuffer<JCCase> cases = new ListBuffer<>();
3628 for (JCCase c : tree.cases) {
3629 if (c.pat != null) {
3630 VarSymbol label = (VarSymbol)TreeInfo.symbol(c.pat);
3631 JCLiteral pat = map.forConstant(label);
3632 cases.append(make.Case(pat, c.stats));
3633 } else {
3634 cases.append(c);
3635 }
3636 }
3637 JCSwitch enumSwitch = make.Switch(selector, cases.toList());
3638 patchTargets(enumSwitch, tree, enumSwitch);
3639 return enumSwitch;
3640 }
3641
3642 public JCTree visitStringSwitch(JCSwitch tree) {
3643 List<JCCase> caseList = tree.getCases();
3644 int alternatives = caseList.size();
3645
3646 if (alternatives == 0) { // Strange but legal possibility
3647 return make.at(tree.pos()).Exec(attr.makeNullCheck(tree.getExpression()));
3648 } else {
3649 /*
3650 * The general approach used is to translate a single
3651 * string switch statement into a series of two chained
3652 * switch statements: the first a synthesized statement
3653 * switching on the argument string's hash value and
3654 * computing a string's position in the list of original
3655 * case labels, if any, followed by a second switch on the
3656 * computed integer value. The second switch has the same
3657 * code structure as the original string switch statement
3658 * except that the string case labels are replaced with
3659 * positional integer constants starting at 0.
3660 *
3661 * The first switch statement can be thought of as an
3662 * inlined map from strings to their position in the case
3663 * label list. An alternate implementation would use an
3664 * actual Map for this purpose, as done for enum switches.
3665 *
3666 * With some additional effort, it would be possible to
3667 * use a single switch statement on the hash code of the
3668 * argument, but care would need to be taken to preserve
3669 * the proper control flow in the presence of hash
3670 * collisions and other complications, such as
3671 * fallthroughs. Switch statements with one or two
3672 * alternatives could also be specially translated into
3673 * if-then statements to omit the computation of the hash
3674 * code.
3675 *
3676 * The generated code assumes that the hashing algorithm
3677 * of String is the same in the compilation environment as
3678 * in the environment the code will run in. The string
3679 * hashing algorithm in the SE JDK has been unchanged
3680 * since at least JDK 1.2. Since the algorithm has been
3681 * specified since that release as well, it is very
3682 * unlikely to be changed in the future.
3683 *
3684 * Different hashing algorithms, such as the length of the
3685 * strings or a perfect hashing algorithm over the
3686 * particular set of case labels, could potentially be
3687 * used instead of String.hashCode.
3688 */
3689
3690 ListBuffer<JCStatement> stmtList = new ListBuffer<>();
3691
3692 // Map from String case labels to their original position in
3693 // the list of case labels.
3694 Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f);
3695
3696 // Map of hash codes to the string case labels having that hashCode.
3697 Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f);
3698
3699 int casePosition = 0;
3700 for(JCCase oneCase : caseList) {
3701 JCExpression expression = oneCase.getExpression();
3702
3703 if (expression != null) { // expression for a "default" case is null
3704 String labelExpr = (String) expression.type.constValue();
3705 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition);
3706 Assert.checkNull(mapping);
3707 int hashCode = labelExpr.hashCode();
3708
3709 Set<String> stringSet = hashToString.get(hashCode);
3710 if (stringSet == null) {
3711 stringSet = new LinkedHashSet<>(1, 1.0f);
3712 stringSet.add(labelExpr);
3713 hashToString.put(hashCode, stringSet);
3714 } else {
3715 boolean added = stringSet.add(labelExpr);
3716 Assert.check(added);
3717 }
3718 }
3719 casePosition++;
3720 }
3721
3722 // Synthesize a switch statement that has the effect of
3723 // mapping from a string to the integer position of that
3724 // string in the list of case labels. This is done by
3725 // switching on the hashCode of the string followed by an
3726 // if-then-else chain comparing the input for equality
3727 // with all the case labels having that hash value.
3728
3729 /*
3730 * s$ = top of stack;
3731 * tmp$ = -1;
3732 * switch($s.hashCode()) {
3733 * case caseLabel.hashCode:
3734 * if (s$.equals("caseLabel_1")
3735 * tmp$ = caseLabelToPosition("caseLabel_1");
3736 * else if (s$.equals("caseLabel_2"))
3737 * tmp$ = caseLabelToPosition("caseLabel_2");
3738 * ...
3739 * break;
3740 * ...
3741 * }
3742 */
3743
3744 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
3745 names.fromString("s" + tree.pos + target.syntheticNameChar()),
3746 syms.stringType,
3747 currentMethodSym);
3748 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, tree.getExpression()).setType(dollar_s.type));
3749
3750 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC,
3751 names.fromString("tmp" + tree.pos + target.syntheticNameChar()),
3752 syms.intType,
3753 currentMethodSym);
3754 JCVariableDecl dollar_tmp_def =
3755 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type);
3756 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType;
3757 stmtList.append(dollar_tmp_def);
3758 ListBuffer<JCCase> caseBuffer = new ListBuffer<>();
3759 // hashCode will trigger nullcheck on original switch expression
3760 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s),
3761 names.hashCode,
3762 List.<JCExpression>nil()).setType(syms.intType);
3763 JCSwitch switch1 = make.Switch(hashCodeCall,
3764 caseBuffer.toList());
3765 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) {
3766 int hashCode = entry.getKey();
3767 Set<String> stringsWithHashCode = entry.getValue();
3768 Assert.check(stringsWithHashCode.size() >= 1);
3769
3770 JCStatement elsepart = null;
3771 for(String caseLabel : stringsWithHashCode ) {
3772 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s),
3773 names.equals,
3774 List.<JCExpression>of(make.Literal(caseLabel)));
3775 elsepart = make.If(stringEqualsCall,
3776 make.Exec(make.Assign(make.Ident(dollar_tmp),
3777 make.Literal(caseLabelToPosition.get(caseLabel))).
3778 setType(dollar_tmp.type)),
3779 elsepart);
3780 }
3781
3782 ListBuffer<JCStatement> lb = new ListBuffer<>();
3783 JCBreak breakStmt = make.Break(null);
3784 breakStmt.target = switch1;
3785 lb.append(elsepart).append(breakStmt);
3786
3787 caseBuffer.append(make.Case(make.Literal(hashCode), lb.toList()));
3788 }
3789
3790 switch1.cases = caseBuffer.toList();
3791 stmtList.append(switch1);
3792
3793 // Make isomorphic switch tree replacing string labels
3794 // with corresponding integer ones from the label to
3795 // position map.
3796
3797 ListBuffer<JCCase> lb = new ListBuffer<>();
3798 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList());
3799 for(JCCase oneCase : caseList ) {
3800 // Rewire up old unlabeled break statements to the
3801 // replacement switch being created.
3802 patchTargets(oneCase, tree, switch2);
3803
3804 boolean isDefault = (oneCase.getExpression() == null);
3805 JCExpression caseExpr;
3806 if (isDefault)
3807 caseExpr = null;
3808 else {
3809 caseExpr = make.Literal(caseLabelToPosition.get((String)TreeInfo.skipParens(oneCase.
3810 getExpression()).
3811 type.constValue()));
3812 }
3813
3814 lb.append(make.Case(caseExpr,
3815 oneCase.getStatements()));
3816 }
3817
3818 switch2.cases = lb.toList();
3819 stmtList.append(switch2);
3820
3821 return make.Block(0L, stmtList.toList());
3822 }
3823 }
3824
3825 public void visitNewArray(JCNewArray tree) {
3826 tree.elemtype = translate(tree.elemtype);
3827 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail)
3828 if (t.head != null) t.head = translate(t.head, syms.intType);
3829 tree.elems = translate(tree.elems, types.elemtype(tree.type));
3830 result = tree;
3831 }
3832
3833 public void visitSelect(JCFieldAccess tree) {
3834 // need to special case-access of the form C.super.x
3835 // these will always need an access method, unless C
3836 // is a default interface subclassed by the current class.
3837 boolean qualifiedSuperAccess =
3838 tree.selected.hasTag(SELECT) &&
3839 TreeInfo.name(tree.selected) == names._super &&
3840 !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass);
3841 tree.selected = translate(tree.selected);
3842 if (tree.name == names._class) {
3843 result = classOf(tree.selected);
3844 }
3845 else if (tree.name == names._super &&
3846 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) {
3847 //default super call!! Not a classic qualified super call
3848 TypeSymbol supSym = tree.selected.type.tsym;
3849 Assert.checkNonNull(types.asSuper(currentClass.type, supSym));
3850 result = tree;
3851 }
3852 else if (tree.name == names._this || tree.name == names._super) {
3853 result = makeThis(tree.pos(), tree.selected.type.tsym);
3854 }
3855 else
3856 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess);
3857 }
3858
3859 public void visitLetExpr(LetExpr tree) {
3860 tree.defs = translateVarDefs(tree.defs);
3861 tree.expr = translate(tree.expr, tree.type);
3862 result = tree;
3863 }
3864
3865 // There ought to be nothing to rewrite here;
3866 // we don't generate code.
3867 public void visitAnnotation(JCAnnotation tree) {
3868 result = tree;
3869 }
3870
3871 @Override
3872 public void visitTry(JCTry tree) {
3873 if (tree.resources.nonEmpty()) {
3874 result = makeTwrTry(tree);
3875 return;
3876 }
3877
3878 boolean hasBody = tree.body.getStatements().nonEmpty();
3879 boolean hasCatchers = tree.catchers.nonEmpty();
3880 boolean hasFinally = tree.finalizer != null &&
3881 tree.finalizer.getStatements().nonEmpty();
3882
3883 if (!hasCatchers && !hasFinally) {
3884 result = translate(tree.body);
3885 return;
3886 }
3887
3888 if (!hasBody) {
3889 if (hasFinally) {
3890 result = translate(tree.finalizer);
3891 } else {
3892 result = translate(tree.body);
3893 }
3894 return;
3895 }
3896
3897 // no optimizations possible
3898 super.visitTry(tree);
3899 }
3900
3901 /**************************************************************************
3902 * main method
3903 *************************************************************************/
3904
3905 /** Translate a toplevel class and return a list consisting of
3906 * the translated class and translated versions of all inner classes.
3907 * @param env The attribution environment current at the class definition.
3908 * We need this for resolving some additional symbols.
3909 * @param cdef The tree representing the class definition.
3910 */
3911 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) {
3912 ListBuffer<JCTree> translated = null;
3913 try {
3914 attrEnv = env;
3915 this.make = make;
3916 endPosTable = env.toplevel.endPositions;
3917 currentClass = null;
3918 currentMethodDef = null;
3919 outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null;
3920 outermostMemberDef = null;
3921 this.translated = new ListBuffer<>();
3922 classdefs = new HashMap<>();
3923 actualSymbols = new HashMap<>();
3924 freevarCache = new HashMap<>();
3925 proxies = WriteableScope.create(syms.noSymbol);
3926 twrVars = WriteableScope.create(syms.noSymbol);
3927 outerThisStack = List.nil();
3928 accessNums = new HashMap<>();
3929 accessSyms = new HashMap<>();
3930 accessConstrs = new HashMap<>();
3931 accessConstrTags = List.nil();
3932 accessed = new ListBuffer<>();
3933 translate(cdef, (JCExpression)null);
3934 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail)
3935 makeAccessible(l.head);
3936 for (EnumMapping map : enumSwitchMap.values())
3937 map.translate();
3938 checkConflicts(this.translated.toList());
3939 checkAccessConstructorTags();
3940 translated = this.translated;
3941 } finally {
3942 // note that recursive invocations of this method fail hard
3943 attrEnv = null;
3944 this.make = null;
3945 endPosTable = null;
3946 currentClass = null;
3947 currentMethodDef = null;
3948 outermostClassDef = null;
3949 outermostMemberDef = null;
3950 this.translated = null;
3951 classdefs = null;
3952 actualSymbols = null;
3953 freevarCache = null;
3954 proxies = null;
3955 outerThisStack = null;
3956 accessNums = null;
3957 accessSyms = null;
3958 accessConstrs = null;
3959 accessConstrTags = null;
3960 accessed = null;
3961 enumSwitchMap.clear();
3962 assertionsDisabledClassCache = null;
3963 }
3964 return translated.toList();
3965 }
3966 }