1 /*
2 * Copyright (c) 1999, 2021, 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 import java.util.stream.Collectors;
30
31 import com.sun.tools.javac.code.*;
32 import com.sun.tools.javac.code.Kinds.KindSelector;
33 import com.sun.tools.javac.code.Scope.WriteableScope;
34 import com.sun.tools.javac.jvm.*;
35 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
36 import com.sun.tools.javac.main.Option.PkgInfo;
37 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
38 import com.sun.tools.javac.tree.*;
39 import com.sun.tools.javac.util.*;
40 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
41 import com.sun.tools.javac.util.List;
42
43 import com.sun.tools.javac.code.Symbol.*;
44 import com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode;
45 import com.sun.tools.javac.resources.CompilerProperties.Errors;
46 import com.sun.tools.javac.tree.JCTree.*;
47 import com.sun.tools.javac.code.Type.*;
48
49 import com.sun.tools.javac.jvm.Target;
50 import com.sun.tools.javac.tree.EndPosTable;
51
52 import static com.sun.tools.javac.code.Flags.*;
53 import static com.sun.tools.javac.code.Flags.BLOCK;
54 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
55 import static com.sun.tools.javac.code.TypeTag.*;
56 import static com.sun.tools.javac.code.Kinds.Kind.*;
57 import static com.sun.tools.javac.jvm.ByteCodes.*;
58 import com.sun.tools.javac.tree.JCTree.JCBreak;
59 import com.sun.tools.javac.tree.JCTree.JCCase;
60 import com.sun.tools.javac.tree.JCTree.JCExpression;
61 import com.sun.tools.javac.tree.JCTree.JCExpressionStatement;
62 import static com.sun.tools.javac.tree.JCTree.JCOperatorExpression.OperandPos.LEFT;
63 import com.sun.tools.javac.tree.JCTree.JCSwitchExpression;
64 import static com.sun.tools.javac.tree.JCTree.Tag.*;
65
66 /** This pass translates away some syntactic sugar: inner classes,
67 * class literals, assertions, foreach loops, etc.
68 *
69 * <p><b>This is NOT part of any supported API.
70 * If you write code that depends on this, you do so at your own risk.
71 * This code and its internal interfaces are subject to change or
72 * deletion without notice.</b>
73 */
74 public class Lower extends TreeTranslator {
75 protected static final Context.Key<Lower> lowerKey = new Context.Key<>();
76
77 public static Lower instance(Context context) {
78 Lower instance = context.get(lowerKey);
79 if (instance == null)
80 instance = new Lower(context);
81 return instance;
82 }
83
84 private final Names names;
85 private final Log log;
86 private final Symtab syms;
87 private final Resolve rs;
88 private final Operators operators;
89 private final Check chk;
90 private final Attr attr;
91 private TreeMaker make;
92 private DiagnosticPosition make_pos;
93 private final ConstFold cfolder;
94 private final Target target;
95 private final TypeEnvs typeEnvs;
96 private final Name dollarAssertionsDisabled;
97 private final Types types;
98 private final boolean debugLower;
99 private final boolean disableProtectedAccessors; // experimental
100 private final PkgInfo pkginfoOpt;
101
102 protected Lower(Context context) {
103 context.put(lowerKey, this);
104 names = Names.instance(context);
105 log = Log.instance(context);
106 syms = Symtab.instance(context);
107 rs = Resolve.instance(context);
108 operators = Operators.instance(context);
109 chk = Check.instance(context);
110 attr = Attr.instance(context);
111 make = TreeMaker.instance(context);
112 cfolder = ConstFold.instance(context);
113 target = Target.instance(context);
114 typeEnvs = TypeEnvs.instance(context);
115 dollarAssertionsDisabled = names.
116 fromString(target.syntheticNameChar() + "assertionsDisabled");
117
118 types = Types.instance(context);
119 Options options = Options.instance(context);
120 debugLower = options.isSet("debuglower");
121 pkginfoOpt = PkgInfo.get(options);
122 disableProtectedAccessors = options.isSet("disableProtectedAccessors");
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 @Override
264 public void visitYield(JCYield tree) {
265 scan(tree.value);
266 }
267
268 }
269
270 /**
271 * Lower-specific subclass of {@code BasicFreeVarCollector}.
272 */
273 class FreeVarCollector extends BasicFreeVarCollector {
274
275 /** The owner of the local class.
276 */
277 Symbol owner;
278
279 /** The local class.
280 */
281 ClassSymbol clazz;
282
283 /** The list of owner's variables accessed from within the local class,
284 * without any duplicates.
285 */
286 List<VarSymbol> fvs;
287
288 FreeVarCollector(ClassSymbol clazz) {
289 this.clazz = clazz;
290 this.owner = clazz.owner;
291 this.fvs = List.nil();
292 }
293
294 /** Add free variable to fvs list unless it is already there.
295 */
296 private void addFreeVar(VarSymbol v) {
297 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail)
298 if (l.head == v) return;
299 fvs = fvs.prepend(v);
300 }
301
302 @Override
303 void addFreeVars(ClassSymbol c) {
304 List<VarSymbol> fvs = freevarCache.get(c);
305 if (fvs != null) {
306 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
307 addFreeVar(l.head);
308 }
309 }
310 }
311
312 @Override
313 void visitSymbol(Symbol _sym) {
314 Symbol sym = _sym;
315 if (sym.kind == VAR || sym.kind == MTH) {
316 if (sym != null && sym.owner != owner)
317 sym = proxies.get(sym);
318 if (sym != null && sym.owner == owner) {
319 VarSymbol v = (VarSymbol)sym;
320 if (v.getConstValue() == null) {
321 addFreeVar(v);
322 }
323 } else {
324 if (outerThisStack.head != null &&
325 outerThisStack.head != _sym)
326 visitSymbol(outerThisStack.head);
327 }
328 }
329 }
330
331 /** If tree refers to a class instance creation expression
332 * add all free variables of the freshly created class.
333 */
334 public void visitNewClass(JCNewClass tree) {
335 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
336 if (tree.encl == null &&
337 c.hasOuterInstance() &&
338 outerThisStack.head != null)
339 visitSymbol(outerThisStack.head);
340 super.visitNewClass(tree);
341 }
342
343 /** If tree refers to a qualified this or super expression
344 * for anything but the current class, add the outer this
345 * stack as a free variable.
346 */
347 public void visitSelect(JCFieldAccess tree) {
348 if ((tree.name == names._this || tree.name == names._super) &&
349 tree.selected.type.tsym != clazz &&
350 outerThisStack.head != null)
351 visitSymbol(outerThisStack.head);
352 super.visitSelect(tree);
353 }
354
355 /** If tree refers to a superclass constructor call,
356 * add all free variables of the superclass.
357 */
358 public void visitApply(JCMethodInvocation tree) {
359 if (TreeInfo.name(tree.meth) == names._super) {
360 Symbol constructor = TreeInfo.symbol(tree.meth);
361 ClassSymbol c = (ClassSymbol)constructor.owner;
362 if (c.hasOuterInstance() &&
363 !tree.meth.hasTag(SELECT) &&
364 outerThisStack.head != null)
365 visitSymbol(outerThisStack.head);
366 }
367 super.visitApply(tree);
368 }
369
370 }
371
372 ClassSymbol ownerToCopyFreeVarsFrom(ClassSymbol c) {
373 if (!c.isDirectlyOrIndirectlyLocal()) {
374 return null;
375 }
376 Symbol currentOwner = c.owner;
377 while (currentOwner.owner.kind.matches(KindSelector.TYP) && currentOwner.isDirectlyOrIndirectlyLocal()) {
378 currentOwner = currentOwner.owner;
379 }
380 if (currentOwner.owner.kind.matches(KindSelector.VAL_MTH) && c.isSubClass(currentOwner, types)) {
381 return (ClassSymbol)currentOwner;
382 }
383 return null;
384 }
385
386 /** Return the variables accessed from within a local class, which
387 * are declared in the local class' owner.
388 * (in reverse order of first access).
389 */
390 List<VarSymbol> freevars(ClassSymbol c) {
391 List<VarSymbol> fvs = freevarCache.get(c);
392 if (fvs != null) {
393 return fvs;
394 }
395 if (c.owner.kind.matches(KindSelector.VAL_MTH)) {
396 FreeVarCollector collector = new FreeVarCollector(c);
397 collector.scan(classDef(c));
398 fvs = collector.fvs;
399 freevarCache.put(c, fvs);
400 return fvs;
401 } else {
402 ClassSymbol owner = ownerToCopyFreeVarsFrom(c);
403 if (owner != null) {
404 fvs = freevarCache.get(owner);
405 freevarCache.put(c, fvs);
406 return fvs;
407 } else {
408 return List.nil();
409 }
410 }
411 }
412
413 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>();
414
415 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) {
416 EnumMapping map = enumSwitchMap.get(enumClass);
417 if (map == null)
418 enumSwitchMap.put(enumClass, map = new EnumMapping(pos, enumClass));
419 return map;
420 }
421
422 /** This map gives a translation table to be used for enum
423 * switches.
424 *
425 * <p>For each enum that appears as the type of a switch
426 * expression, we maintain an EnumMapping to assist in the
427 * translation, as exemplified by the following example:
428 *
429 * <p>we translate
430 * <pre>
431 * switch(colorExpression) {
432 * case red: stmt1;
433 * case green: stmt2;
434 * }
435 * </pre>
436 * into
437 * <pre>
438 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) {
439 * case 1: stmt1;
440 * case 2: stmt2
441 * }
442 * </pre>
443 * with the auxiliary table initialized as follows:
444 * <pre>
445 * class Outer$0 {
446 * synthetic final int[] $EnumMap$Color = new int[Color.values().length];
447 * static {
448 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {}
449 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {}
450 * }
451 * }
452 * </pre>
453 * class EnumMapping provides mapping data and support methods for this translation.
454 */
455 class EnumMapping {
456 EnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) {
457 this.forEnum = forEnum;
458 this.values = new LinkedHashMap<>();
459 this.pos = pos;
460 Name varName = names
461 .fromString(target.syntheticNameChar() +
462 "SwitchMap" +
463 target.syntheticNameChar() +
464 names.fromUtf(ClassWriter.externalize(forEnum.type.tsym.flatName())).toString()
465 .replace('/', '.')
466 .replace('.', target.syntheticNameChar()));
467 ClassSymbol outerCacheClass = outerCacheClass();
468 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL,
469 varName,
470 new ArrayType(syms.intType, syms.arrayClass),
471 outerCacheClass);
472 enterSynthetic(pos, mapVar, outerCacheClass.members());
473 }
474
475 DiagnosticPosition pos = null;
476
477 // the next value to use
478 int next = 1; // 0 (unused map elements) go to the default label
479
480 // the enum for which this is a map
481 final TypeSymbol forEnum;
482
483 // the field containing the map
484 final VarSymbol mapVar;
485
486 // the mapped values
487 final Map<VarSymbol,Integer> values;
488
489 JCLiteral forConstant(VarSymbol v) {
490 Integer result = values.get(v);
491 if (result == null)
492 values.put(v, result = next++);
493 return make.Literal(result);
494 }
495
496 // generate the field initializer for the map
497 void translate() {
498 make.at(pos.getStartPosition());
499 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner);
500
501 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length];
502 MethodSymbol valuesMethod = lookupMethod(pos,
503 names.values,
504 forEnum.type,
505 List.nil());
506 JCExpression size = make // Color.values().length
507 .Select(make.App(make.QualIdent(valuesMethod)),
508 syms.lengthVar);
509 JCExpression mapVarInit = make
510 .NewArray(make.Type(syms.intType), List.of(size), null)
511 .setType(new ArrayType(syms.intType, syms.arrayClass));
512
513 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {}
514 ListBuffer<JCStatement> stmts = new ListBuffer<>();
515 Symbol ordinalMethod = lookupMethod(pos,
516 names.ordinal,
517 forEnum.type,
518 List.nil());
519 List<JCCatch> catcher = List.<JCCatch>nil()
520 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex,
521 syms.noSuchFieldErrorType,
522 syms.noSymbol),
523 null),
524 make.Block(0, List.nil())));
525 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) {
526 VarSymbol enumerator = e.getKey();
527 Integer mappedValue = e.getValue();
528 JCExpression assign = make
529 .Assign(make.Indexed(mapVar,
530 make.App(make.Select(make.QualIdent(enumerator),
531 ordinalMethod))),
532 make.Literal(mappedValue))
533 .setType(syms.intType);
534 JCStatement exec = make.Exec(assign);
535 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null);
536 stmts.append(_try);
537 }
538
539 owner.defs = owner.defs
540 .prepend(make.Block(STATIC, stmts.toList()))
541 .prepend(make.VarDef(mapVar, mapVarInit));
542 }
543 }
544
545
546 /**************************************************************************
547 * Tree building blocks
548 *************************************************************************/
549
550 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching
551 * pos as make_pos, for use in diagnostics.
552 **/
553 TreeMaker make_at(DiagnosticPosition pos) {
554 make_pos = pos;
555 return make.at(pos);
556 }
557
558 /** Make an attributed tree representing a literal. This will be an
559 * Ident node in the case of boolean literals, a Literal node in all
560 * other cases.
561 * @param type The literal's type.
562 * @param value The literal's value.
563 */
564 JCExpression makeLit(Type type, Object value) {
565 return make.Literal(type.getTag(), value).setType(type.constType(value));
566 }
567
568 /** Make an attributed tree representing null.
569 */
570 JCExpression makeNull() {
571 return makeLit(syms.botType, null);
572 }
573
574 /** Make an attributed class instance creation expression.
575 * @param ctype The class type.
576 * @param args The constructor arguments.
577 */
578 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
579 JCNewClass tree = make.NewClass(null,
580 null, make.QualIdent(ctype.tsym), args, null);
581 tree.constructor = rs.resolveConstructor(
582 make_pos, attrEnv, ctype, TreeInfo.types(args), List.nil());
583 tree.type = ctype;
584 return tree;
585 }
586
587 /** Make an attributed unary expression.
588 * @param optag The operators tree tag.
589 * @param arg The operator's argument.
590 */
591 JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) {
592 JCUnary tree = make.Unary(optag, arg);
593 tree.operator = operators.resolveUnary(tree, optag, arg.type);
594 tree.type = tree.operator.type.getReturnType();
595 return tree;
596 }
597
598 /** Make an attributed binary expression.
599 * @param optag The operators tree tag.
600 * @param lhs The operator's left argument.
601 * @param rhs The operator's right argument.
602 */
603 JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) {
604 JCBinary tree = make.Binary(optag, lhs, rhs);
605 tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type);
606 tree.type = tree.operator.type.getReturnType();
607 return tree;
608 }
609
610 /** Make an attributed assignop expression.
611 * @param optag The operators tree tag.
612 * @param lhs The operator's left argument.
613 * @param rhs The operator's right argument.
614 */
615 JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) {
616 JCAssignOp tree = make.Assignop(optag, lhs, rhs);
617 tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type);
618 tree.type = lhs.type;
619 return tree;
620 }
621
622 /** Convert tree into string object, unless it has already a
623 * reference type..
624 */
625 JCExpression makeString(JCExpression tree) {
626 if (!tree.type.isPrimitiveOrVoid()) {
627 return tree;
628 } else {
629 Symbol valueOfSym = lookupMethod(tree.pos(),
630 names.valueOf,
631 syms.stringType,
632 List.of(tree.type));
633 return make.App(make.QualIdent(valueOfSym), List.of(tree));
634 }
635 }
636
637 /** Create an empty anonymous class definition and enter and complete
638 * its symbol. Return the class definition's symbol.
639 * and create
640 * @param flags The class symbol's flags
641 * @param owner The class symbol's owner
642 */
643 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) {
644 return makeEmptyClass(flags, owner, null, true);
645 }
646
647 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname,
648 boolean addToDefs) {
649 // Create class symbol.
650 ClassSymbol c = syms.defineClass(names.empty, owner);
651 if (flatname != null) {
652 c.flatname = flatname;
653 } else {
654 c.flatname = chk.localClassName(c);
655 }
656 c.sourcefile = owner.sourcefile;
657 c.completer = Completer.NULL_COMPLETER;
658 c.members_field = WriteableScope.create(c);
659 c.flags_field = flags;
660 ClassType ctype = (ClassType) c.type;
661 ctype.supertype_field = syms.objectType;
662 ctype.interfaces_field = List.nil();
663
664 JCClassDecl odef = classDef(owner);
665
666 // Enter class symbol in owner scope and compiled table.
667 enterSynthetic(odef.pos(), c, owner.members());
668 chk.putCompiled(c);
669
670 // Create class definition tree.
671 JCClassDecl cdef = make.ClassDef(
672 make.Modifiers(flags), names.empty,
673 List.nil(),
674 null, List.nil(), List.nil());
675 cdef.sym = c;
676 cdef.type = c.type;
677
678 // Append class definition tree to owner's definitions.
679 if (addToDefs) odef.defs = odef.defs.prepend(cdef);
680 return cdef;
681 }
682
683 /**************************************************************************
684 * Symbol manipulation utilities
685 *************************************************************************/
686
687 /** Enter a synthetic symbol in a given scope, but complain if there was already one there.
688 * @param pos Position for error reporting.
689 * @param sym The symbol.
690 * @param s The scope.
691 */
692 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) {
693 s.enter(sym);
694 }
695
696 /** Create a fresh synthetic name within a given scope - the unique name is
697 * obtained by appending '$' chars at the end of the name until no match
698 * is found.
699 *
700 * @param name base name
701 * @param s scope in which the name has to be unique
702 * @return fresh synthetic name
703 */
704 private Name makeSyntheticName(Name name, Scope s) {
705 do {
706 name = name.append(
707 target.syntheticNameChar(),
708 names.empty);
709 } while (lookupSynthetic(name, s) != null);
710 return name;
711 }
712
713 /** Check whether synthetic symbols generated during lowering conflict
714 * with user-defined symbols.
715 *
716 * @param translatedTrees lowered class trees
717 */
718 void checkConflicts(List<JCTree> translatedTrees) {
719 for (JCTree t : translatedTrees) {
720 t.accept(conflictsChecker);
721 }
722 }
723
724 JCTree.Visitor conflictsChecker = new TreeScanner() {
725
726 TypeSymbol currentClass;
727
728 @Override
729 public void visitMethodDef(JCMethodDecl that) {
730 checkConflicts(that.pos(), that.sym, currentClass);
731 super.visitMethodDef(that);
732 }
733
734 @Override
735 public void visitVarDef(JCVariableDecl that) {
736 if (that.sym.owner.kind == TYP) {
737 checkConflicts(that.pos(), that.sym, currentClass);
738 }
739 super.visitVarDef(that);
740 }
741
742 @Override
743 public void visitClassDef(JCClassDecl that) {
744 TypeSymbol prevCurrentClass = currentClass;
745 currentClass = that.sym;
746 try {
747 super.visitClassDef(that);
748 }
749 finally {
750 currentClass = prevCurrentClass;
751 }
752 }
753
754 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
755 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
756 for (Symbol sym2 : ct.tsym.members().getSymbolsByName(sym.name, NON_RECURSIVE)) {
757 // VM allows methods and variables with differing types
758 if (sym.kind == sym2.kind &&
759 types.isSameType(types.erasure(sym.type), types.erasure(sym2.type)) &&
760 sym != sym2 &&
761 (sym.flags() & Flags.SYNTHETIC) != (sym2.flags() & Flags.SYNTHETIC) &&
762 (sym.flags() & BRIDGE) == 0 && (sym2.flags() & BRIDGE) == 0) {
763 syntheticError(pos, (sym2.flags() & SYNTHETIC) == 0 ? sym2 : sym);
764 return;
765 }
766 }
767 }
768 }
769
770 /** Report a conflict between a user symbol and a synthetic symbol.
771 */
772 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
773 if (!sym.type.isErroneous()) {
774 log.error(pos, Errors.CannotGenerateClass(sym.location(), Fragments.SyntheticNameConflict(sym, sym.location())));
775 }
776 }
777 };
778
779 /** Look up a synthetic name in a given scope.
780 * @param s The scope.
781 * @param name The name.
782 */
783 private Symbol lookupSynthetic(Name name, Scope s) {
784 Symbol sym = s.findFirst(name);
785 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym;
786 }
787
788 /** Look up a method in a given scope.
789 */
790 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) {
791 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.nil());
792 }
793
794 /** Anon inner classes are used as access constructor tags.
795 * accessConstructorTag will use an existing anon class if one is available,
796 * and synthesize a class (with makeEmptyClass) if one is not available.
797 * However, there is a small possibility that an existing class will not
798 * be generated as expected if it is inside a conditional with a constant
799 * expression. If that is found to be the case, create an empty class tree here.
800 */
801 private void checkAccessConstructorTags() {
802 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) {
803 ClassSymbol c = l.head;
804 if (isTranslatedClassAvailable(c))
805 continue;
806 // Create class definition tree.
807 JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC,
808 c.outermostClass(), c.flatname, false);
809 swapAccessConstructorTag(c, cdec.sym);
810 translated.append(cdec);
811 }
812 }
813 // where
814 private boolean isTranslatedClassAvailable(ClassSymbol c) {
815 for (JCTree tree: translated) {
816 if (tree.hasTag(CLASSDEF)
817 && ((JCClassDecl) tree).sym == c) {
818 return true;
819 }
820 }
821 return false;
822 }
823
824 void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) {
825 for (MethodSymbol methodSymbol : accessConstrs.values()) {
826 Assert.check(methodSymbol.type.hasTag(METHOD));
827 MethodType oldMethodType =
828 (MethodType)methodSymbol.type;
829 if (oldMethodType.argtypes.head.tsym == oldCTag)
830 methodSymbol.type =
831 types.createMethodTypeWithParameters(oldMethodType,
832 oldMethodType.getParameterTypes().tail
833 .prepend(newCTag.erasure(types)));
834 }
835 }
836
837 /**************************************************************************
838 * Access methods
839 *************************************************************************/
840
841 /** A mapping from symbols to their access numbers.
842 */
843 private Map<Symbol,Integer> accessNums;
844
845 /** A mapping from symbols to an array of access symbols, indexed by
846 * access code.
847 */
848 private Map<Symbol,MethodSymbol[]> accessSyms;
849
850 /** A mapping from (constructor) symbols to access constructor symbols.
851 */
852 private Map<Symbol,MethodSymbol> accessConstrs;
853
854 /** A list of all class symbols used for access constructor tags.
855 */
856 private List<ClassSymbol> accessConstrTags;
857
858 /** A queue for all accessed symbols.
859 */
860 private ListBuffer<Symbol> accessed;
861
862 /** return access code for identifier,
863 * @param tree The tree representing the identifier use.
864 * @param enclOp The closest enclosing operation node of tree,
865 * null if tree is not a subtree of an operation.
866 */
867 private static int accessCode(JCTree tree, JCTree enclOp) {
868 if (enclOp == null)
869 return AccessCode.DEREF.code;
870 else if (enclOp.hasTag(ASSIGN) &&
871 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs))
872 return AccessCode.ASSIGN.code;
873 else if (enclOp.hasTag(WITHFIELD) &&
874 tree == TreeInfo.skipParens(((JCWithField) enclOp).field))
875 return AccessCode.WITHFIELD.code;
876 else if ((enclOp.getTag().isIncOrDecUnaryOp() || enclOp.getTag().isAssignop()) &&
877 tree == TreeInfo.skipParens(((JCOperatorExpression) enclOp).getOperand(LEFT)))
878 return (((JCOperatorExpression) enclOp).operator).getAccessCode(enclOp.getTag());
879 else
880 return AccessCode.DEREF.code;
881 }
882
883 /** Return binary operator that corresponds to given access code.
884 */
885 private OperatorSymbol binaryAccessOperator(int acode, Tag tag) {
886 return operators.lookupBinaryOp(op -> op.getAccessCode(tag) == acode);
887 }
888
889 /** Return tree tag for assignment operation corresponding
890 * to given binary operator.
891 */
892 private static JCTree.Tag treeTag(OperatorSymbol operator) {
893 switch (operator.opcode) {
894 case ByteCodes.ior: case ByteCodes.lor:
895 return BITOR_ASG;
896 case ByteCodes.ixor: case ByteCodes.lxor:
897 return BITXOR_ASG;
898 case ByteCodes.iand: case ByteCodes.land:
899 return BITAND_ASG;
900 case ByteCodes.ishl: case ByteCodes.lshl:
901 case ByteCodes.ishll: case ByteCodes.lshll:
902 return SL_ASG;
903 case ByteCodes.ishr: case ByteCodes.lshr:
904 case ByteCodes.ishrl: case ByteCodes.lshrl:
905 return SR_ASG;
906 case ByteCodes.iushr: case ByteCodes.lushr:
907 case ByteCodes.iushrl: case ByteCodes.lushrl:
908 return USR_ASG;
909 case ByteCodes.iadd: case ByteCodes.ladd:
910 case ByteCodes.fadd: case ByteCodes.dadd:
911 case ByteCodes.string_add:
912 return PLUS_ASG;
913 case ByteCodes.isub: case ByteCodes.lsub:
914 case ByteCodes.fsub: case ByteCodes.dsub:
915 return MINUS_ASG;
916 case ByteCodes.imul: case ByteCodes.lmul:
917 case ByteCodes.fmul: case ByteCodes.dmul:
918 return MUL_ASG;
919 case ByteCodes.idiv: case ByteCodes.ldiv:
920 case ByteCodes.fdiv: case ByteCodes.ddiv:
921 return DIV_ASG;
922 case ByteCodes.imod: case ByteCodes.lmod:
923 case ByteCodes.fmod: case ByteCodes.dmod:
924 return MOD_ASG;
925 default:
926 throw new AssertionError();
927 }
928 }
929
930 /** The name of the access method with number `anum' and access code `acode'.
931 */
932 Name accessName(int anum, int acode) {
933 return names.fromString(
934 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10);
935 }
936
937 /** Return access symbol for a private or protected symbol from an inner class.
938 * @param sym The accessed private symbol.
939 * @param tree The accessing tree.
940 * @param enclOp The closest enclosing operation node of tree,
941 * null if tree is not a subtree of an operation.
942 * @param protAccess Is access to a protected symbol in another
943 * package?
944 * @param refSuper Is access via a (qualified) C.super?
945 */
946 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp,
947 boolean protAccess, boolean refSuper) {
948 ClassSymbol accOwner = refSuper && protAccess
949 // For access via qualified super (T.super.x), place the
950 // access symbol on T.
951 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym
952 // Otherwise pretend that the owner of an accessed
953 // protected symbol is the enclosing class of the current
954 // class which is a subclass of the symbol's owner.
955 : accessClass(sym, protAccess, tree);
956
957 Symbol vsym = sym;
958 if (sym.owner != accOwner) {
959 vsym = sym.clone(accOwner);
960 actualSymbols.put(vsym, sym);
961 }
962
963 Integer anum // The access number of the access method.
964 = accessNums.get(vsym);
965 if (anum == null) {
966 anum = accessed.length();
967 accessNums.put(vsym, anum);
968 accessSyms.put(vsym, new MethodSymbol[AccessCode.numberOfAccessCodes]);
969 accessed.append(vsym);
970 // System.out.println("accessing " + vsym + " in " + vsym.location());
971 }
972
973 int acode; // The access code of the access method.
974 List<Type> argtypes; // The argument types of the access method.
975 Type restype; // The result type of the access method.
976 List<Type> thrown; // The thrown exceptions of the access method.
977 switch (vsym.kind) {
978 case VAR:
979 acode = accessCode(tree, enclOp);
980 if (acode >= AccessCode.FIRSTASGOP.code) {
981 OperatorSymbol operator = binaryAccessOperator(acode, enclOp.getTag());
982 if (operator.opcode == string_add)
983 argtypes = List.of(syms.objectType);
984 else
985 argtypes = operator.type.getParameterTypes().tail;
986 } else if (acode == AccessCode.ASSIGN.code || acode == AccessCode.WITHFIELD.code)
987 argtypes = List.of(vsym.erasure(types));
988 else
989 argtypes = List.nil();
990 restype = acode == AccessCode.WITHFIELD.code ? vsym.owner.erasure(types) : vsym.erasure(types);
991 thrown = List.nil();
992 break;
993 case MTH:
994 acode = AccessCode.DEREF.code;
995 argtypes = vsym.erasure(types).getParameterTypes();
996 restype = vsym.erasure(types).getReturnType();
997 thrown = vsym.type.getThrownTypes();
998 break;
999 default:
1000 throw new AssertionError();
1001 }
1002
1003 // For references via qualified super, increment acode by one,
1004 // making it odd.
1005 if (protAccess && refSuper) acode++;
1006
1007 // Instance access methods get instance as first parameter.
1008 // For protected symbols this needs to be the instance as a member
1009 // of the type containing the accessed symbol, not the class
1010 // containing the access method.
1011 if ((vsym.flags() & STATIC) == 0) {
1012 argtypes = argtypes.prepend(vsym.owner.erasure(types));
1013 }
1014 MethodSymbol[] accessors = accessSyms.get(vsym);
1015 MethodSymbol accessor = accessors[acode];
1016 if (accessor == null) {
1017 accessor = new MethodSymbol(
1018 STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0),
1019 accessName(anum.intValue(), acode),
1020 new MethodType(argtypes, restype, thrown, syms.methodClass),
1021 accOwner);
1022 enterSynthetic(tree.pos(), accessor, accOwner.members());
1023 accessors[acode] = accessor;
1024 }
1025 return accessor;
1026 }
1027
1028 /** The qualifier to be used for accessing a symbol in an outer class.
1029 * This is either C.sym or C.this.sym, depending on whether or not
1030 * sym is static.
1031 * @param sym The accessed symbol.
1032 */
1033 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) {
1034 return (sym.flags() & STATIC) != 0
1035 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner))
1036 : makeOwnerThis(pos, sym, true);
1037 }
1038
1039 /** Do we need an access method to reference private symbol?
1040 */
1041 boolean needsPrivateAccess(Symbol sym) {
1042 if (target.hasNestmateAccess()) {
1043 return false;
1044 }
1045 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) {
1046 return false;
1047 } else if (sym.name == names.init && sym.owner.isDirectlyOrIndirectlyLocal()) {
1048 // private constructor in local class: relax protection
1049 sym.flags_field &= ~PRIVATE;
1050 return false;
1051 } else {
1052 return true;
1053 }
1054 }
1055
1056 /** Do we need an access method to reference symbol in other package?
1057 */
1058 boolean needsProtectedAccess(Symbol sym, JCTree tree) {
1059 if (disableProtectedAccessors) return false;
1060 if ((sym.flags() & PROTECTED) == 0 ||
1061 sym.owner.owner == currentClass.owner || // fast special case
1062 sym.packge() == currentClass.packge())
1063 return false;
1064 if (!currentClass.isSubClass(sym.owner, types))
1065 return true;
1066 if ((sym.flags() & STATIC) != 0 ||
1067 !tree.hasTag(SELECT) ||
1068 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super)
1069 return false;
1070 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types);
1071 }
1072
1073 /** The class in which an access method for given symbol goes.
1074 * @param sym The access symbol
1075 * @param protAccess Is access to a protected symbol in another
1076 * package?
1077 */
1078 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) {
1079 if (protAccess) {
1080 Symbol qualifier = null;
1081 ClassSymbol c = currentClass;
1082 if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) {
1083 qualifier = ((JCFieldAccess) tree).selected.type.tsym;
1084 while (!qualifier.isSubClass(c, types)) {
1085 c = c.owner.enclClass();
1086 }
1087 return c;
1088 } else {
1089 while (!c.isSubClass(sym.owner, types)) {
1090 c = c.owner.enclClass();
1091 }
1092 }
1093 return c;
1094 } else {
1095 // the symbol is private
1096 return sym.owner.enclClass();
1097 }
1098 }
1099
1100 private void addPrunedInfo(JCTree tree) {
1101 List<JCTree> infoList = prunedTree.get(currentClass);
1102 infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree);
1103 prunedTree.put(currentClass, infoList);
1104 }
1105
1106 /** Ensure that identifier is accessible, return tree accessing the identifier.
1107 * @param sym The accessed symbol.
1108 * @param tree The tree referring to the symbol.
1109 * @param enclOp The closest enclosing operation node of tree,
1110 * null if tree is not a subtree of an operation.
1111 * @param refSuper Is access via a (qualified) C.super?
1112 */
1113 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) {
1114 // Access a free variable via its proxy, or its proxy's proxy
1115 while (sym.kind == VAR && sym.owner.kind == MTH &&
1116 sym.owner.enclClass() != currentClass) {
1117 // A constant is replaced by its constant value.
1118 Object cv = ((VarSymbol)sym).getConstValue();
1119 if (cv != null) {
1120 make.at(tree.pos);
1121 return makeLit(sym.type, cv);
1122 }
1123 if (lambdaTranslationMap != null && lambdaTranslationMap.get(sym) != null) {
1124 return make.at(tree.pos).Ident(lambdaTranslationMap.get(sym));
1125 } else {
1126 // Otherwise replace the variable by its proxy.
1127 sym = proxies.get(sym);
1128 Assert.check(sym != null && (sym.flags_field & FINAL) != 0);
1129 tree = make.at(tree.pos).Ident(sym);
1130 }
1131 }
1132 JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null;
1133 switch (sym.kind) {
1134 case TYP:
1135 if (sym.owner.kind != PCK) {
1136 // Make sure not to lose type fidelity due to symbol sharing between projections
1137 boolean requireReferenceProjection =
1138 tree.hasTag(SELECT) && ((JCFieldAccess) tree).name == names.ref && tree.type.isReferenceProjection();
1139 // Convert type idents to
1140 // <flat name> or <package name> . <flat name>
1141 Name flatname = Convert.shortName(sym.flatName());
1142 while (base != null &&
1143 TreeInfo.symbol(base) != null &&
1144 TreeInfo.symbol(base).kind != PCK) {
1145 base = (base.hasTag(SELECT))
1146 ? ((JCFieldAccess) base).selected
1147 : null;
1148 }
1149 if (tree.hasTag(IDENT)) {
1150 ((JCIdent) tree).name = flatname;
1151 } else if (base == null) {
1152 tree = make.at(tree.pos).Ident(sym);
1153 ((JCIdent) tree).name = flatname;
1154 if (requireReferenceProjection) {
1155 tree.setType(tree.type.referenceProjection());
1156 }
1157 } else {
1158 ((JCFieldAccess) tree).selected = base;
1159 ((JCFieldAccess) tree).name = flatname;
1160 if (requireReferenceProjection) {
1161 tree.setType(tree.type.referenceProjection());
1162 }
1163 }
1164 }
1165 break;
1166 case MTH: case VAR:
1167 if (sym.owner.kind == TYP) {
1168
1169 // Access methods are required for
1170 // - private members,
1171 // - protected members in a superclass of an
1172 // enclosing class contained in another package.
1173 // - all non-private members accessed via a qualified super.
1174 boolean protAccess = refSuper && !needsPrivateAccess(sym)
1175 || needsProtectedAccess(sym, tree);
1176 boolean accReq = protAccess || needsPrivateAccess(sym);
1177
1178 // A base has to be supplied for
1179 // - simple identifiers accessing variables in outer classes.
1180 boolean baseReq =
1181 base == null &&
1182 sym.owner != syms.predefClass &&
1183 !sym.isMemberOf(currentClass, types);
1184
1185 if (accReq || baseReq) {
1186 make.at(tree.pos);
1187
1188 // Constants are replaced by their constant value.
1189 if (sym.kind == VAR) {
1190 Object cv = ((VarSymbol)sym).getConstValue();
1191 if (cv != null) {
1192 addPrunedInfo(tree);
1193 return makeLit(sym.type, cv);
1194 }
1195 }
1196
1197 // Private variables and methods are replaced by calls
1198 // to their access methods.
1199 if (accReq) {
1200 List<JCExpression> args = List.nil();
1201 if ((sym.flags() & STATIC) == 0) {
1202 // Instance access methods get instance
1203 // as first parameter.
1204 if (base == null)
1205 base = makeOwnerThis(tree.pos(), sym, true);
1206 args = args.prepend(base);
1207 base = null; // so we don't duplicate code
1208 }
1209 Symbol access = accessSymbol(sym, tree,
1210 enclOp, protAccess,
1211 refSuper);
1212 JCExpression receiver = make.Select(
1213 base != null ? base : make.QualIdent(access.owner),
1214 access);
1215 return make.App(receiver, args);
1216
1217 // Other accesses to members of outer classes get a
1218 // qualifier.
1219 } else if (baseReq) {
1220 return make.at(tree.pos).Select(
1221 accessBase(tree.pos(), sym), sym).setType(tree.type);
1222 }
1223 }
1224 } else if (sym.owner.kind == MTH && lambdaTranslationMap != null) {
1225 //sym is a local variable - check the lambda translation map to
1226 //see if sym has been translated to something else in the current
1227 //scope (by LambdaToMethod)
1228 Symbol translatedSym = lambdaTranslationMap.get(sym.baseSymbol());
1229 if (translatedSym != null) {
1230 tree = make.at(tree.pos).Ident(translatedSym);
1231 }
1232 }
1233 }
1234 return tree;
1235 }
1236
1237 /** Ensure that identifier is accessible, return tree accessing the identifier.
1238 * @param tree The identifier tree.
1239 */
1240 JCExpression access(JCExpression tree) {
1241 Symbol sym = TreeInfo.symbol(tree);
1242 return sym == null ? tree : access(sym, tree, null, false);
1243 }
1244
1245 /** Return access constructor for a private constructor,
1246 * or the constructor itself, if no access constructor is needed.
1247 * @param pos The position to report diagnostics, if any.
1248 * @param constr The private constructor.
1249 */
1250 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) {
1251 if (needsPrivateAccess(constr)) {
1252 ClassSymbol accOwner = constr.owner.enclClass();
1253 MethodSymbol aconstr = accessConstrs.get(constr);
1254 if (aconstr == null) {
1255 List<Type> argtypes = constr.type.getParameterTypes();
1256 if ((accOwner.flags_field & ENUM) != 0)
1257 argtypes = argtypes
1258 .prepend(syms.intType)
1259 .prepend(syms.stringType);
1260 aconstr = new MethodSymbol(
1261 SYNTHETIC,
1262 names.init,
1263 new MethodType(
1264 argtypes.append(
1265 accessConstructorTag().erasure(types)),
1266 constr.type.getReturnType(),
1267 constr.type.getThrownTypes(),
1268 syms.methodClass),
1269 accOwner);
1270 enterSynthetic(pos, aconstr, accOwner.members());
1271 accessConstrs.put(constr, aconstr);
1272 accessed.append(constr);
1273 }
1274 return aconstr;
1275 } else {
1276 return constr;
1277 }
1278 }
1279
1280 /** Return an anonymous class nested in this toplevel class.
1281 */
1282 ClassSymbol accessConstructorTag() {
1283 ClassSymbol topClass = currentClass.outermostClass();
1284 ModuleSymbol topModle = topClass.packge().modle;
1285 for (int i = 1; ; i++) {
1286 Name flatname = names.fromString("" + topClass.getQualifiedName() +
1287 target.syntheticNameChar() +
1288 i);
1289 ClassSymbol ctag = chk.getCompiled(topModle, flatname);
1290 if (ctag == null)
1291 ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym;
1292 else if (!ctag.isAnonymous())
1293 continue;
1294 // keep a record of all tags, to verify that all are generated as required
1295 accessConstrTags = accessConstrTags.prepend(ctag);
1296 return ctag;
1297 }
1298 }
1299
1300 /** Add all required access methods for a private symbol to enclosing class.
1301 * @param sym The symbol.
1302 */
1303 void makeAccessible(Symbol sym) {
1304 JCClassDecl cdef = classDef(sym.owner.enclClass());
1305 if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner);
1306 if (sym.name == names.init) {
1307 cdef.defs = cdef.defs.prepend(
1308 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym)));
1309 } else {
1310 MethodSymbol[] accessors = accessSyms.get(sym);
1311 for (int i = 0; i < AccessCode.numberOfAccessCodes; i++) {
1312 if (accessors[i] != null)
1313 cdef.defs = cdef.defs.prepend(
1314 accessDef(cdef.pos, sym, accessors[i], i));
1315 }
1316 }
1317 }
1318
1319 /** Construct definition of an access method.
1320 * @param pos The source code position of the definition.
1321 * @param vsym The private or protected symbol.
1322 * @param accessor The access method for the symbol.
1323 * @param acode The access code.
1324 */
1325 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) {
1326 // System.err.println("access " + vsym + " with " + accessor);//DEBUG
1327 currentClass = vsym.owner.enclClass();
1328 make.at(pos);
1329 JCMethodDecl md = make.MethodDef(accessor, null);
1330
1331 // Find actual symbol
1332 Symbol sym = actualSymbols.get(vsym);
1333 if (sym == null) sym = vsym;
1334
1335 JCExpression ref; // The tree referencing the private symbol.
1336 List<JCExpression> args; // Any additional arguments to be passed along.
1337 if ((sym.flags() & STATIC) != 0) {
1338 ref = make.Ident(sym);
1339 args = make.Idents(md.params);
1340 } else {
1341 JCExpression site = make.Ident(md.params.head);
1342 if (acode % 2 != 0) {
1343 //odd access codes represent qualified super accesses - need to
1344 //emit reference to the direct superclass, even if the referred
1345 //member is from an indirect superclass (JLS 13.1)
1346 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type)));
1347 }
1348 ref = make.Select(site, sym);
1349 args = make.Idents(md.params.tail);
1350 }
1351 JCStatement stat; // The statement accessing the private symbol.
1352 if (sym.kind == VAR) {
1353 // Normalize out all odd access codes by taking floor modulo 2:
1354 int acode1 = acode - (acode & 1);
1355
1356 JCExpression expr; // The access method's return value.
1357 AccessCode aCode = AccessCode.getFromCode(acode1);
1358 switch (aCode) {
1359 case DEREF:
1360 expr = ref;
1361 break;
1362 case ASSIGN:
1363 expr = make.Assign(ref, args.head);
1364 break;
1365 case PREINC: case POSTINC: case PREDEC: case POSTDEC:
1366 expr = makeUnary(aCode.tag, ref);
1367 break;
1368 case WITHFIELD:
1369 expr = make.WithField(ref, args.head);
1370 break;
1371 default:
1372 expr = make.Assignop(
1373 treeTag(binaryAccessOperator(acode1, JCTree.Tag.NO_TAG)), ref, args.head);
1374 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1, JCTree.Tag.NO_TAG);
1375 }
1376 stat = make.Return(expr.setType(aCode == AccessCode.WITHFIELD ? sym.owner.type : sym.type));
1377 } else {
1378 stat = make.Call(make.App(ref, args));
1379 }
1380 md.body = make.Block(0, List.of(stat));
1381
1382 // Make sure all parameters, result types and thrown exceptions
1383 // are accessible.
1384 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail)
1385 l.head.vartype = access(l.head.vartype);
1386 md.restype = access(md.restype);
1387 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail)
1388 l.head = access(l.head);
1389
1390 return md;
1391 }
1392
1393 /** Construct definition of an access constructor.
1394 * @param pos The source code position of the definition.
1395 * @param constr The private constructor.
1396 * @param accessor The access method for the constructor.
1397 */
1398 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) {
1399 make.at(pos);
1400 JCMethodDecl md = make.MethodDef(accessor,
1401 accessor.externalType(types),
1402 null);
1403 JCIdent callee = make.Ident(names._this);
1404 callee.sym = constr;
1405 callee.type = constr.type;
1406 md.body =
1407 make.Block(0, List.of(
1408 make.Call(
1409 make.App(
1410 callee,
1411 make.Idents(md.params.reverse().tail.reverse())))));
1412 return md;
1413 }
1414
1415 /**************************************************************************
1416 * Free variables proxies and this$n
1417 *************************************************************************/
1418
1419 /** A map which allows to retrieve the translated proxy variable for any given symbol of an
1420 * enclosing scope that is accessed (the accessed symbol could be the synthetic 'this$n' symbol).
1421 * Inside a constructor, the map temporarily overrides entries corresponding to proxies and any
1422 * 'this$n' symbols, where they represent the constructor parameters.
1423 */
1424 Map<Symbol, Symbol> proxies;
1425
1426 /** A scope containing all unnamed resource variables/saved
1427 * exception variables for translated TWR blocks
1428 */
1429 WriteableScope twrVars;
1430
1431 /** A stack containing the this$n field of the currently translated
1432 * classes (if needed) in innermost first order.
1433 * Inside a constructor, proxies and any this$n symbol are duplicated
1434 * in an additional innermost scope, where they represent the constructor
1435 * parameters.
1436 */
1437 List<VarSymbol> outerThisStack;
1438
1439 /** The name of a free variable proxy.
1440 */
1441 Name proxyName(Name name, int index) {
1442 Name proxyName = names.fromString("val" + target.syntheticNameChar() + name);
1443 if (index > 0) {
1444 proxyName = proxyName.append(names.fromString("" + target.syntheticNameChar() + index));
1445 }
1446 return proxyName;
1447 }
1448
1449 /** Proxy definitions for all free variables in given list, in reverse order.
1450 * @param pos The source code position of the definition.
1451 * @param freevars The free variables.
1452 * @param owner The class in which the definitions go.
1453 */
1454 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) {
1455 return freevarDefs(pos, freevars, owner, 0);
1456 }
1457
1458 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner,
1459 long additionalFlags) {
1460 long flags = FINAL | SYNTHETIC | additionalFlags;
1461 List<JCVariableDecl> defs = List.nil();
1462 Set<Name> proxyNames = new HashSet<>();
1463 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) {
1464 VarSymbol v = l.head;
1465 int index = 0;
1466 Name proxyName;
1467 do {
1468 proxyName = proxyName(v.name, index++);
1469 } while (!proxyNames.add(proxyName));
1470 final Type type = v.erasure(types);
1471 VarSymbol proxy = new VarSymbol(
1472 flags, proxyName, type, owner);
1473 proxies.put(v, proxy);
1474 JCVariableDecl vd = make.at(pos).VarDef(proxy, null);
1475 vd.vartype = access(vd.vartype);
1476 defs = defs.prepend(vd);
1477 }
1478 return defs;
1479 }
1480
1481 /** The name of a this$n field
1482 * @param type The class referenced by the this$n field
1483 */
1484 Name outerThisName(Type type, Symbol owner) {
1485 Type t = type.getEnclosingType();
1486 int nestingLevel = 0;
1487 while (t.hasTag(CLASS)) {
1488 t = t.getEnclosingType();
1489 nestingLevel++;
1490 }
1491 Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel);
1492 while (owner.kind == TYP && ((ClassSymbol)owner).members().findFirst(result) != null)
1493 result = names.fromString(result.toString() + target.syntheticNameChar());
1494 return result;
1495 }
1496
1497 private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) {
1498 Type target = types.erasure(owner.enclClass().type.getEnclosingType());
1499 VarSymbol outerThis =
1500 new VarSymbol(flags, outerThisName(target, owner), target, owner);
1501 outerThisStack = outerThisStack.prepend(outerThis);
1502 return outerThis;
1503 }
1504
1505 private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) {
1506 JCVariableDecl vd = make.at(pos).VarDef(sym, null);
1507 vd.vartype = access(vd.vartype);
1508 return vd;
1509 }
1510
1511 /** Definition for this$n field.
1512 * @param pos The source code position of the definition.
1513 * @param owner The method in which the definition goes.
1514 */
1515 JCVariableDecl outerThisDef(int pos, MethodSymbol owner) {
1516 ClassSymbol c = owner.enclClass();
1517 boolean isMandated =
1518 // Anonymous constructors
1519 (owner.isConstructor() && owner.isAnonymous()) ||
1520 // Constructors of non-private inner member classes
1521 (owner.isConstructor() && c.isInner() &&
1522 !c.isPrivate() && !c.isStatic());
1523 long flags =
1524 FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER;
1525 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags);
1526 owner.extraParams = owner.extraParams.prepend(outerThis);
1527 return makeOuterThisVarDecl(pos, outerThis);
1528 }
1529
1530 /** Definition for this$n field.
1531 * @param pos The source code position of the definition.
1532 * @param owner The class in which the definition goes.
1533 */
1534 JCVariableDecl outerThisDef(int pos, ClassSymbol owner) {
1535 Type target = types.erasure(owner.enclClass().type.getEnclosingType());
1536 long flags = FINAL | SYNTHETIC;
1537 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags);
1538 return makeOuterThisVarDecl(pos, outerThis);
1539 }
1540
1541 /** Return a list of trees that load the free variables in given list,
1542 * in reverse order.
1543 * @param pos The source code position to be used for the trees.
1544 * @param freevars The list of free variables.
1545 */
1546 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) {
1547 List<JCExpression> args = List.nil();
1548 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail)
1549 args = args.prepend(loadFreevar(pos, l.head));
1550 return args;
1551 }
1552 //where
1553 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) {
1554 return access(v, make.at(pos).Ident(v), null, false);
1555 }
1556
1557 /** Construct a tree simulating the expression {@code C.this}.
1558 * @param pos The source code position to be used for the tree.
1559 * @param c The qualifier class.
1560 */
1561 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) {
1562 if (currentClass == c) {
1563 // in this case, `this' works fine
1564 return make.at(pos).This(c.erasure(types));
1565 } else {
1566 // need to go via this$n
1567 return makeOuterThis(pos, c);
1568 }
1569 }
1570
1571 /**
1572 * Optionally replace a try statement with the desugaring of a
1573 * try-with-resources statement. The canonical desugaring of
1574 *
1575 * try ResourceSpecification
1576 * Block
1577 *
1578 * is
1579 *
1580 * {
1581 * final VariableModifiers_minus_final R #resource = Expression;
1582 *
1583 * try ResourceSpecificationtail
1584 * Block
1585 * } body-only-finally {
1586 * if (#resource != null) //nullcheck skipped if Expression is provably non-null
1587 * #resource.close();
1588 * } catch (Throwable #primaryException) {
1589 * if (#resource != null) //nullcheck skipped if Expression is provably non-null
1590 * try {
1591 * #resource.close();
1592 * } catch (Throwable #suppressedException) {
1593 * #primaryException.addSuppressed(#suppressedException);
1594 * }
1595 * throw #primaryException;
1596 * }
1597 * }
1598 *
1599 * @param tree The try statement to inspect.
1600 * @return A a desugared try-with-resources tree, or the original
1601 * try block if there are no resources to manage.
1602 */
1603 JCTree makeTwrTry(JCTry tree) {
1604 make_at(tree.pos());
1605 twrVars = twrVars.dup();
1606 JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body, 0);
1607 if (tree.catchers.isEmpty() && tree.finalizer == null)
1608 result = translate(twrBlock);
1609 else
1610 result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer));
1611 twrVars = twrVars.leave();
1612 return result;
1613 }
1614
1615 private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block, int depth) {
1616 if (resources.isEmpty())
1617 return block;
1618
1619 // Add resource declaration or expression to block statements
1620 ListBuffer<JCStatement> stats = new ListBuffer<>();
1621 JCTree resource = resources.head;
1622 JCExpression resourceUse;
1623 boolean resourceNonNull;
1624 if (resource instanceof JCVariableDecl variableDecl) {
1625 resourceUse = make.Ident(variableDecl.sym).setType(resource.type);
1626 resourceNonNull = variableDecl.init != null && TreeInfo.skipParens(variableDecl.init).hasTag(NEWCLASS);
1627 stats.add(variableDecl);
1628 } else {
1629 Assert.check(resource instanceof JCExpression);
1630 VarSymbol syntheticTwrVar =
1631 new VarSymbol(SYNTHETIC | FINAL,
1632 makeSyntheticName(names.fromString("twrVar" +
1633 depth), twrVars),
1634 (resource.type.hasTag(BOT)) ?
1635 syms.autoCloseableType : resource.type,
1636 currentMethodSym);
1637 twrVars.enter(syntheticTwrVar);
1638 JCVariableDecl syntheticTwrVarDecl =
1639 make.VarDef(syntheticTwrVar, (JCExpression)resource);
1640 resourceUse = (JCExpression)make.Ident(syntheticTwrVar);
1641 resourceNonNull = false;
1642 stats.add(syntheticTwrVarDecl);
1643 }
1644
1645 //create (semi-) finally block that will be copied into the main try body:
1646 int oldPos = make.pos;
1647 make.at(TreeInfo.endPos(block));
1648
1649 // if (#resource != null) { #resource.close(); }
1650 JCStatement bodyCloseStatement = makeResourceCloseInvocation(resourceUse);
1651
1652 if (!resourceNonNull) {
1653 bodyCloseStatement = make.If(makeNonNullCheck(resourceUse),
1654 bodyCloseStatement,
1655 null);
1656 }
1657
1658 JCBlock finallyClause = make.Block(BODY_ONLY_FINALIZE, List.of(bodyCloseStatement));
1659 make.at(oldPos);
1660
1661 // Create catch clause that saves exception, closes the resource and then rethrows the exception:
1662 VarSymbol primaryException =
1663 new VarSymbol(FINAL|SYNTHETIC,
1664 names.fromString("t" +
1665 target.syntheticNameChar()),
1666 syms.throwableType,
1667 currentMethodSym);
1668 JCVariableDecl primaryExceptionDecl = make.VarDef(primaryException, null);
1669
1670 // close resource:
1671 // try {
1672 // #resource.close();
1673 // } catch (Throwable #suppressedException) {
1674 // #primaryException.addSuppressed(#suppressedException);
1675 // }
1676 VarSymbol suppressedException =
1677 new VarSymbol(SYNTHETIC, make.paramName(2),
1678 syms.throwableType,
1679 currentMethodSym);
1680 JCStatement addSuppressedStatement =
1681 make.Exec(makeCall(make.Ident(primaryException),
1682 names.addSuppressed,
1683 List.of(make.Ident(suppressedException))));
1684 JCBlock closeResourceTryBlock =
1685 make.Block(0L, List.of(makeResourceCloseInvocation(resourceUse)));
1686 JCVariableDecl catchSuppressedDecl = make.VarDef(suppressedException, null);
1687 JCBlock catchSuppressedBlock = make.Block(0L, List.of(addSuppressedStatement));
1688 List<JCCatch> catchSuppressedClauses =
1689 List.of(make.Catch(catchSuppressedDecl, catchSuppressedBlock));
1690 JCTry closeResourceTry = make.Try(closeResourceTryBlock, catchSuppressedClauses, null);
1691 closeResourceTry.finallyCanCompleteNormally = true;
1692
1693 JCStatement exceptionalCloseStatement = closeResourceTry;
1694
1695 if (!resourceNonNull) {
1696 // if (#resource != null) { }
1697 exceptionalCloseStatement = make.If(makeNonNullCheck(resourceUse),
1698 exceptionalCloseStatement,
1699 null);
1700 }
1701
1702 JCStatement exceptionalRethrow = make.Throw(make.Ident(primaryException));
1703 JCBlock exceptionalCloseBlock = make.Block(0L, List.of(exceptionalCloseStatement, exceptionalRethrow));
1704 JCCatch exceptionalCatchClause = make.Catch(primaryExceptionDecl, exceptionalCloseBlock);
1705
1706 //create the main try statement with the close:
1707 JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block, depth + 1),
1708 List.of(exceptionalCatchClause),
1709 finallyClause);
1710
1711 outerTry.finallyCanCompleteNormally = true;
1712 stats.add(outerTry);
1713
1714 JCBlock newBlock = make.Block(0L, stats.toList());
1715 return newBlock;
1716 }
1717
1718 private JCStatement makeResourceCloseInvocation(JCExpression resource) {
1719 // convert to AutoCloseable if needed
1720 if (types.asSuper(resource.type.referenceProjectionOrSelf(), syms.autoCloseableType.tsym) == null) {
1721 resource = convert(resource, syms.autoCloseableType);
1722 }
1723
1724 // create resource.close() method invocation
1725 JCExpression resourceClose = makeCall(resource,
1726 names.close,
1727 List.nil());
1728 return make.Exec(resourceClose);
1729 }
1730
1731 private JCExpression makeNonNullCheck(JCExpression expression) {
1732 return makeBinary(NE, expression, makeNull());
1733 }
1734
1735 /** Construct a tree that represents the outer instance
1736 * {@code C.this}. Never pick the current `this'.
1737 * @param pos The source code position to be used for the tree.
1738 * @param c The qualifier class.
1739 */
1740 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) {
1741 List<VarSymbol> ots = outerThisStack;
1742 if (ots.isEmpty()) {
1743 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1744 Assert.error();
1745 return makeNull();
1746 }
1747 VarSymbol ot = ots.head;
1748 JCExpression tree = access(make.at(pos).Ident(ot));
1749 TypeSymbol otc = ot.type.tsym;
1750 while (otc != c) {
1751 do {
1752 ots = ots.tail;
1753 if (ots.isEmpty()) {
1754 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1755 Assert.error(); // should have been caught in Attr
1756 return tree;
1757 }
1758 ot = ots.head;
1759 } while (ot.owner != otc);
1760 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) {
1761 chk.earlyRefError(pos, c);
1762 Assert.error(); // should have been caught in Attr
1763 return makeNull();
1764 }
1765 tree = access(make.at(pos).Select(tree, ot));
1766 otc = ot.type.tsym;
1767 }
1768 return tree;
1769 }
1770
1771 /** Construct a tree that represents the closest outer instance
1772 * {@code C.this} such that the given symbol is a member of C.
1773 * @param pos The source code position to be used for the tree.
1774 * @param sym The accessed symbol.
1775 * @param preciseMatch should we accept a type that is a subtype of
1776 * sym's owner, even if it doesn't contain sym
1777 * due to hiding, overriding, or non-inheritance
1778 * due to protection?
1779 */
1780 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1781 Symbol c = sym.owner;
1782 if (preciseMatch ? sym.isMemberOf(currentClass, types)
1783 : currentClass.isSubClass(sym.owner, types)) {
1784 // in this case, `this' works fine
1785 return make.at(pos).This(c.erasure(types));
1786 } else {
1787 // need to go via this$n
1788 return makeOwnerThisN(pos, sym, preciseMatch);
1789 }
1790 }
1791
1792 /**
1793 * Similar to makeOwnerThis but will never pick "this".
1794 */
1795 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1796 Symbol c = sym.owner;
1797 List<VarSymbol> ots = outerThisStack;
1798 if (ots.isEmpty()) {
1799 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1800 Assert.error();
1801 return makeNull();
1802 }
1803 VarSymbol ot = ots.head;
1804 JCExpression tree = access(make.at(pos).Ident(ot));
1805 TypeSymbol otc = ot.type.tsym;
1806 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) {
1807 do {
1808 ots = ots.tail;
1809 if (ots.isEmpty()) {
1810 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1811 Assert.error();
1812 return tree;
1813 }
1814 ot = ots.head;
1815 } while (ot.owner != otc);
1816 tree = access(make.at(pos).Select(tree, ot));
1817 otc = ot.type.tsym;
1818 }
1819 return tree;
1820 }
1821
1822 /** Return tree simulating the assignment {@code this.name = name}, where
1823 * name is the name of a free variable.
1824 */
1825 JCStatement initField(int pos, Symbol rhs, Symbol lhs) {
1826 Assert.check(rhs.owner.kind == MTH);
1827 Assert.check(rhs.owner.owner == lhs.owner);
1828 make.at(pos);
1829 return
1830 make.Exec(
1831 make.Assign(
1832 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1833 make.Ident(rhs)).setType(lhs.erasure(types)));
1834 }
1835
1836 /** Return tree simulating the assignment {@code this.this$n = this$n}.
1837 */
1838 JCStatement initOuterThis(int pos) {
1839 VarSymbol rhs = outerThisStack.head;
1840 Assert.check(rhs.owner.kind == MTH);
1841 VarSymbol lhs = outerThisStack.tail.head;
1842 Assert.check(rhs.owner.owner == lhs.owner);
1843 make.at(pos);
1844 return
1845 make.Exec(
1846 make.Assign(
1847 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1848 make.Ident(rhs)).setType(lhs.erasure(types)));
1849 }
1850
1851 /**************************************************************************
1852 * Code for .class
1853 *************************************************************************/
1854
1855 /** Return the symbol of a class to contain a cache of
1856 * compiler-generated statics such as class$ and the
1857 * $assertionsDisabled flag. We create an anonymous nested class
1858 * (unless one already exists) and return its symbol. However,
1859 * for backward compatibility in 1.4 and earlier we use the
1860 * top-level class itself.
1861 */
1862 private ClassSymbol outerCacheClass() {
1863 ClassSymbol clazz = outermostClassDef.sym;
1864 Scope s = clazz.members();
1865 for (Symbol sym : s.getSymbols(NON_RECURSIVE))
1866 if (sym.kind == TYP &&
1867 sym.name == names.empty &&
1868 (sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym;
1869 return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym;
1870 }
1871
1872 /** Create an attributed tree of the form left.name(). */
1873 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) {
1874 Assert.checkNonNull(left.type);
1875 Symbol funcsym = lookupMethod(make_pos, name, left.type,
1876 TreeInfo.types(args));
1877 return make.App(make.Select(left, funcsym), args);
1878 }
1879
1880 /** The tree simulating a T.class expression.
1881 * @param clazz The tree identifying type T.
1882 */
1883 private JCExpression classOf(JCTree clazz) {
1884 return classOfType(clazz.type, clazz.pos());
1885 }
1886
1887 private JCExpression classOfType(Type type, DiagnosticPosition pos) {
1888 switch (type.getTag()) {
1889 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT:
1890 case DOUBLE: case BOOLEAN: case VOID:
1891 // replace with <BoxedClass>.TYPE
1892 ClassSymbol c = types.boxedClass(type);
1893 Symbol typeSym =
1894 rs.accessBase(
1895 rs.findIdentInType(pos, attrEnv, c.type, names.TYPE, KindSelector.VAR),
1896 pos, c.type, names.TYPE, true);
1897 if (typeSym.kind == VAR)
1898 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated
1899 return make.QualIdent(typeSym);
1900 case CLASS: case ARRAY:
1901 VarSymbol sym = new VarSymbol(
1902 STATIC | PUBLIC | FINAL, names._class,
1903 syms.classType, type.tsym);
1904 return make_at(pos).Select(make.Type(type), sym);
1905 default:
1906 throw new AssertionError();
1907 }
1908 }
1909
1910 /**************************************************************************
1911 * Code for enabling/disabling assertions.
1912 *************************************************************************/
1913
1914 private ClassSymbol assertionsDisabledClassCache;
1915
1916 /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces.
1917 */
1918 private ClassSymbol assertionsDisabledClass() {
1919 if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache;
1920
1921 assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym;
1922
1923 return assertionsDisabledClassCache;
1924 }
1925
1926 // This code is not particularly robust if the user has
1927 // previously declared a member named '$assertionsDisabled'.
1928 // The same faulty idiom also appears in the translation of
1929 // class literals above. We should report an error if a
1930 // previous declaration is not synthetic.
1931
1932 private JCExpression assertFlagTest(DiagnosticPosition pos) {
1933 // Outermost class may be either true class or an interface.
1934 ClassSymbol outermostClass = outermostClassDef.sym;
1935
1936 //only classes can hold a non-public field, look for a usable one:
1937 ClassSymbol container = !currentClass.isInterface() ? currentClass :
1938 assertionsDisabledClass();
1939
1940 VarSymbol assertDisabledSym =
1941 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled,
1942 container.members());
1943 if (assertDisabledSym == null) {
1944 assertDisabledSym =
1945 new VarSymbol(STATIC | FINAL | SYNTHETIC,
1946 dollarAssertionsDisabled,
1947 syms.booleanType,
1948 container);
1949 enterSynthetic(pos, assertDisabledSym, container.members());
1950 Symbol desiredAssertionStatusSym = lookupMethod(pos,
1951 names.desiredAssertionStatus,
1952 types.erasure(syms.classType),
1953 List.nil());
1954 JCClassDecl containerDef = classDef(container);
1955 make_at(containerDef.pos());
1956 JCExpression notStatus = makeUnary(NOT, make.App(make.Select(
1957 classOfType(types.erasure(outermostClass.type),
1958 containerDef.pos()),
1959 desiredAssertionStatusSym)));
1960 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym,
1961 notStatus);
1962 containerDef.defs = containerDef.defs.prepend(assertDisabledDef);
1963
1964 if (currentClass.isInterface()) {
1965 //need to load the assertions enabled/disabled state while
1966 //initializing the interface:
1967 JCClassDecl currentClassDef = classDef(currentClass);
1968 make_at(currentClassDef.pos());
1969 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null);
1970 JCBlock clinit = make.Block(STATIC, List.of(dummy));
1971 currentClassDef.defs = currentClassDef.defs.prepend(clinit);
1972 }
1973 }
1974 make_at(pos);
1975 return makeUnary(NOT, make.Ident(assertDisabledSym));
1976 }
1977
1978
1979 /**************************************************************************
1980 * Building blocks for let expressions
1981 *************************************************************************/
1982
1983 interface TreeBuilder {
1984 JCExpression build(JCExpression arg);
1985 }
1986
1987 /** Construct an expression using the builder, with the given rval
1988 * expression as an argument to the builder. However, the rval
1989 * expression must be computed only once, even if used multiple
1990 * times in the result of the builder. We do that by
1991 * constructing a "let" expression that saves the rvalue into a
1992 * temporary variable and then uses the temporary variable in
1993 * place of the expression built by the builder. The complete
1994 * resulting expression is of the form
1995 * <pre>
1996 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>;
1997 * in (<b>BUILDER</b>(<b>TEMP</b>)))
1998 * </pre>
1999 * where <code><b>TEMP</b></code> is a newly declared variable
2000 * in the let expression.
2001 */
2002 JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) {
2003 rval = TreeInfo.skipParens(rval);
2004 switch (rval.getTag()) {
2005 case LITERAL:
2006 return builder.build(rval);
2007 case IDENT:
2008 JCIdent id = (JCIdent) rval;
2009 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH)
2010 return builder.build(rval);
2011 }
2012 Name name = TreeInfo.name(rval);
2013 if (name == names._super || name == names._this)
2014 return builder.build(rval);
2015 VarSymbol var =
2016 new VarSymbol(FINAL|SYNTHETIC,
2017 names.fromString(
2018 target.syntheticNameChar()
2019 + "" + rval.hashCode()),
2020 type,
2021 currentMethodSym);
2022 rval = convert(rval,type);
2023 JCVariableDecl def = make.VarDef(var, rval); // XXX cast
2024 JCExpression built = builder.build(make.Ident(var));
2025 JCExpression res = make.LetExpr(def, built);
2026 res.type = built.type;
2027 return res;
2028 }
2029
2030 // same as above, with the type of the temporary variable computed
2031 JCExpression abstractRval(JCExpression rval, TreeBuilder builder) {
2032 return abstractRval(rval, rval.type, builder);
2033 }
2034
2035 // same as above, but for an expression that may be used as either
2036 // an rvalue or an lvalue. This requires special handling for
2037 // Select expressions, where we place the left-hand-side of the
2038 // select in a temporary, and for Indexed expressions, where we
2039 // place both the indexed expression and the index value in temps.
2040 JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) {
2041 lval = TreeInfo.skipParens(lval);
2042 switch (lval.getTag()) {
2043 case IDENT:
2044 return builder.build(lval);
2045 case SELECT: {
2046 final JCFieldAccess s = (JCFieldAccess)lval;
2047 Symbol lid = TreeInfo.symbol(s.selected);
2048 if (lid != null && lid.kind == TYP) return builder.build(lval);
2049 return abstractRval(s.selected, selected -> builder.build(make.Select(selected, s.sym)));
2050 }
2051 case INDEXED: {
2052 final JCArrayAccess i = (JCArrayAccess)lval;
2053 return abstractRval(i.indexed, indexed -> abstractRval(i.index, syms.intType, index -> {
2054 JCExpression newLval = make.Indexed(indexed, index);
2055 newLval.setType(i.type);
2056 return builder.build(newLval);
2057 }));
2058 }
2059 case TYPECAST: {
2060 return abstractLval(((JCTypeCast)lval).expr, builder);
2061 }
2062 }
2063 throw new AssertionError(lval);
2064 }
2065
2066 // evaluate and discard the first expression, then evaluate the second.
2067 JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) {
2068 JCExpression res = make.LetExpr(List.of(make.Exec(expr1)), expr2);
2069 res.type = expr2.type;
2070 return res;
2071 }
2072
2073 /**************************************************************************
2074 * Translation methods
2075 *************************************************************************/
2076
2077 /** Visitor argument: enclosing operator node.
2078 */
2079 private JCExpression enclOp;
2080
2081 /** Visitor method: Translate a single node.
2082 * Attach the source position from the old tree to its replacement tree.
2083 */
2084 @Override
2085 public <T extends JCTree> T translate(T tree) {
2086 if (tree == null) {
2087 return null;
2088 } else {
2089 make_at(tree.pos());
2090 T result = super.translate(tree);
2091 if (endPosTable != null && result != tree) {
2092 endPosTable.replaceTree(tree, result);
2093 }
2094 return result;
2095 }
2096 }
2097
2098 /** Visitor method: Translate a single node, boxing or unboxing if needed.
2099 */
2100 public <T extends JCExpression> T translate(T tree, Type type) {
2101 return (tree == null) ? null :
2102 applyPrimitiveConversionsAsNeeded(boxIfNeeded(translate(tree), type), type);
2103 }
2104
2105 /** Visitor method: Translate tree.
2106 */
2107 public <T extends JCTree> T translate(T tree, JCExpression enclOp) {
2108 JCExpression prevEnclOp = this.enclOp;
2109 this.enclOp = enclOp;
2110 T res = translate(tree);
2111 this.enclOp = prevEnclOp;
2112 return res;
2113 }
2114
2115 /** Visitor method: Translate list of trees.
2116 */
2117 public <T extends JCExpression> List<T> translate(List<T> trees, Type type) {
2118 if (trees == null) return null;
2119 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
2120 l.head = translate(l.head, type);
2121 return trees;
2122 }
2123
2124 public void visitPackageDef(JCPackageDecl tree) {
2125 if (!needPackageInfoClass(tree))
2126 return;
2127
2128 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2129 // package-info is marked SYNTHETIC in JDK 1.6 and later releases
2130 flags = flags | Flags.SYNTHETIC;
2131 ClassSymbol c = tree.packge.package_info;
2132 c.setAttributes(tree.packge);
2133 c.flags_field |= flags;
2134 ClassType ctype = (ClassType) c.type;
2135 ctype.supertype_field = syms.objectType;
2136 ctype.interfaces_field = List.nil();
2137 createInfoClass(tree.annotations, c);
2138 }
2139 // where
2140 private boolean needPackageInfoClass(JCPackageDecl pd) {
2141 switch (pkginfoOpt) {
2142 case ALWAYS:
2143 return true;
2144 case LEGACY:
2145 return pd.getAnnotations().nonEmpty();
2146 case NONEMPTY:
2147 for (Attribute.Compound a :
2148 pd.packge.getDeclarationAttributes()) {
2149 Attribute.RetentionPolicy p = types.getRetention(a);
2150 if (p != Attribute.RetentionPolicy.SOURCE)
2151 return true;
2152 }
2153 return false;
2154 }
2155 throw new AssertionError();
2156 }
2157
2158 public void visitModuleDef(JCModuleDecl tree) {
2159 ModuleSymbol msym = tree.sym;
2160 ClassSymbol c = msym.module_info;
2161 c.setAttributes(msym);
2162 c.flags_field |= Flags.MODULE;
2163 createInfoClass(List.nil(), tree.sym.module_info);
2164 }
2165
2166 private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) {
2167 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2168 JCClassDecl infoClass =
2169 make.ClassDef(make.Modifiers(flags, annots),
2170 c.name, List.nil(),
2171 null, List.nil(), List.nil());
2172 infoClass.sym = c;
2173 translated.append(infoClass);
2174 }
2175
2176 public void visitClassDef(JCClassDecl tree) {
2177 Env<AttrContext> prevEnv = attrEnv;
2178 ClassSymbol currentClassPrev = currentClass;
2179 MethodSymbol currentMethodSymPrev = currentMethodSym;
2180
2181 currentClass = tree.sym;
2182 currentMethodSym = null;
2183 attrEnv = typeEnvs.remove(currentClass);
2184 if (attrEnv == null)
2185 attrEnv = prevEnv;
2186
2187 classdefs.put(currentClass, tree);
2188
2189 Map<Symbol, Symbol> prevProxies = proxies;
2190 proxies = new HashMap<>(proxies);
2191 List<VarSymbol> prevOuterThisStack = outerThisStack;
2192
2193 // If this is an enum definition
2194 if ((tree.mods.flags & ENUM) != 0 &&
2195 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0)
2196 visitEnumDef(tree);
2197
2198 if ((tree.mods.flags & RECORD) != 0) {
2199 visitRecordDef(tree);
2200 }
2201
2202 // If this is a nested class, define a this$n field for
2203 // it and add to proxies.
2204 JCVariableDecl otdef = null;
2205 if (currentClass.hasOuterInstance())
2206 otdef = outerThisDef(tree.pos, currentClass);
2207
2208 // If this is a local class, define proxies for all its free variables.
2209 List<JCVariableDecl> fvdefs = freevarDefs(
2210 tree.pos, freevars(currentClass), currentClass);
2211
2212 // Recursively translate superclass, interfaces.
2213 tree.extending = translate(tree.extending);
2214 tree.implementing = translate(tree.implementing);
2215
2216 if (currentClass.isDirectlyOrIndirectlyLocal()) {
2217 ClassSymbol encl = currentClass.owner.enclClass();
2218 if (encl.trans_local == null) {
2219 encl.trans_local = List.nil();
2220 }
2221 encl.trans_local = encl.trans_local.prepend(currentClass);
2222 }
2223
2224 // Recursively translate members, taking into account that new members
2225 // might be created during the translation and prepended to the member
2226 // list `tree.defs'.
2227 List<JCTree> seen = List.nil();
2228 while (tree.defs != seen) {
2229 List<JCTree> unseen = tree.defs;
2230 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) {
2231 JCTree outermostMemberDefPrev = outermostMemberDef;
2232 if (outermostMemberDefPrev == null) outermostMemberDef = l.head;
2233 l.head = translate(l.head);
2234 outermostMemberDef = outermostMemberDefPrev;
2235 }
2236 seen = unseen;
2237 }
2238
2239 // Convert a protected modifier to public, mask static modifier.
2240 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC;
2241 tree.mods.flags &= ClassFlags;
2242
2243 // Convert name to flat representation, replacing '.' by '$'.
2244 tree.name = Convert.shortName(currentClass.flatName());
2245
2246 // Add this$n and free variables proxy definitions to class.
2247
2248 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) {
2249 tree.defs = tree.defs.prepend(l.head);
2250 enterSynthetic(tree.pos(), l.head.sym, currentClass.members());
2251 }
2252 if (currentClass.hasOuterInstance()) {
2253 tree.defs = tree.defs.prepend(otdef);
2254 enterSynthetic(tree.pos(), otdef.sym, currentClass.members());
2255 }
2256
2257 proxies = prevProxies;
2258 outerThisStack = prevOuterThisStack;
2259
2260 // Append translated tree to `translated' queue.
2261 translated.append(tree);
2262
2263 attrEnv = prevEnv;
2264 currentClass = currentClassPrev;
2265 currentMethodSym = currentMethodSymPrev;
2266
2267 // Return empty block {} as a placeholder for an inner class.
2268 result = make_at(tree.pos()).Block(SYNTHETIC, List.nil());
2269 }
2270
2271 List<JCTree> generateMandatedAccessors(JCClassDecl tree) {
2272 List<JCVariableDecl> fields = TreeInfo.recordFields(tree);
2273 return tree.sym.getRecordComponents().stream()
2274 .filter(rc -> (rc.accessor.flags() & Flags.GENERATED_MEMBER) != 0)
2275 .map(rc -> {
2276 // we need to return the field not the record component
2277 JCVariableDecl field = fields.stream().filter(f -> f.name == rc.name).findAny().get();
2278 make_at(tree.pos());
2279 return make.MethodDef(rc.accessor, make.Block(0,
2280 List.of(make.Return(make.Ident(field)))));
2281 }).collect(List.collector());
2282 }
2283
2284 /** Translate an enum class. */
2285 private void visitEnumDef(JCClassDecl tree) {
2286 make_at(tree.pos());
2287
2288 // add the supertype, if needed
2289 if (tree.extending == null)
2290 tree.extending = make.Type(types.supertype(tree.type));
2291
2292 // classOfType adds a cache field to tree.defs
2293 JCExpression e_class = classOfType(tree.sym.type, tree.pos()).
2294 setType(types.erasure(syms.classType));
2295
2296 // process each enumeration constant, adding implicit constructor parameters
2297 int nextOrdinal = 0;
2298 ListBuffer<JCExpression> values = new ListBuffer<>();
2299 ListBuffer<JCTree> enumDefs = new ListBuffer<>();
2300 ListBuffer<JCTree> otherDefs = new ListBuffer<>();
2301 for (List<JCTree> defs = tree.defs;
2302 defs.nonEmpty();
2303 defs=defs.tail) {
2304 if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
2305 JCVariableDecl var = (JCVariableDecl)defs.head;
2306 visitEnumConstantDef(var, nextOrdinal++);
2307 values.append(make.QualIdent(var.sym));
2308 enumDefs.append(var);
2309 } else {
2310 otherDefs.append(defs.head);
2311 }
2312 }
2313
2314 // synthetic private static T[] $values() { return new T[] { a, b, c }; }
2315 // synthetic private static final T[] $VALUES = $values();
2316 Name valuesName = syntheticName(tree, "VALUES");
2317 Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass);
2318 VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC,
2319 valuesName,
2320 arrayType,
2321 tree.type.tsym);
2322 JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)),
2323 List.nil(),
2324 values.toList());
2325 newArray.type = arrayType;
2326
2327 MethodSymbol valuesMethod = new MethodSymbol(PRIVATE|STATIC|SYNTHETIC,
2328 syntheticName(tree, "values"),
2329 new MethodType(List.nil(), arrayType, List.nil(), tree.type.tsym),
2330 tree.type.tsym);
2331 enumDefs.append(make.MethodDef(valuesMethod, make.Block(0, List.of(make.Return(newArray)))));
2332 tree.sym.members().enter(valuesMethod);
2333
2334 enumDefs.append(make.VarDef(valuesVar, make.App(make.QualIdent(valuesMethod))));
2335 tree.sym.members().enter(valuesVar);
2336
2337 Symbol valuesSym = lookupMethod(tree.pos(), names.values,
2338 tree.type, List.nil());
2339 List<JCStatement> valuesBody;
2340 if (useClone()) {
2341 // return (T[]) $VALUES.clone();
2342 JCTypeCast valuesResult =
2343 make.TypeCast(valuesSym.type.getReturnType(),
2344 make.App(make.Select(make.Ident(valuesVar),
2345 syms.arrayCloneMethod)));
2346 valuesBody = List.of(make.Return(valuesResult));
2347 } else {
2348 // template: T[] $result = new T[$values.length];
2349 Name resultName = syntheticName(tree, "result");
2350 VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC,
2351 resultName,
2352 arrayType,
2353 valuesSym);
2354 JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)),
2355 List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)),
2356 null);
2357 resultArray.type = arrayType;
2358 JCVariableDecl decl = make.VarDef(resultVar, resultArray);
2359
2360 // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length);
2361 if (systemArraycopyMethod == null) {
2362 systemArraycopyMethod =
2363 new MethodSymbol(PUBLIC | STATIC,
2364 names.fromString("arraycopy"),
2365 new MethodType(List.of(syms.objectType,
2366 syms.intType,
2367 syms.objectType,
2368 syms.intType,
2369 syms.intType),
2370 syms.voidType,
2371 List.nil(),
2372 syms.methodClass),
2373 syms.systemType.tsym);
2374 }
2375 JCStatement copy =
2376 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym),
2377 systemArraycopyMethod),
2378 List.of(make.Ident(valuesVar), make.Literal(0),
2379 make.Ident(resultVar), make.Literal(0),
2380 make.Select(make.Ident(valuesVar), syms.lengthVar))));
2381
2382 // template: return $result;
2383 JCStatement ret = make.Return(make.Ident(resultVar));
2384 valuesBody = List.of(decl, copy, ret);
2385 }
2386
2387 JCMethodDecl valuesDef =
2388 make.MethodDef((MethodSymbol)valuesSym, make.Block(0, valuesBody));
2389
2390 enumDefs.append(valuesDef);
2391
2392 if (debugLower)
2393 System.err.println(tree.sym + ".valuesDef = " + valuesDef);
2394
2395 /** The template for the following code is:
2396 *
2397 * public static E valueOf(String name) {
2398 * return (E)Enum.valueOf(E.class, name);
2399 * }
2400 *
2401 * where E is tree.sym
2402 */
2403 MethodSymbol valueOfSym = lookupMethod(tree.pos(),
2404 names.valueOf,
2405 tree.sym.type,
2406 List.of(syms.stringType));
2407 Assert.check((valueOfSym.flags() & STATIC) != 0);
2408 VarSymbol nameArgSym = valueOfSym.params.head;
2409 JCIdent nameVal = make.Ident(nameArgSym);
2410 JCStatement enum_ValueOf =
2411 make.Return(make.TypeCast(tree.sym.type,
2412 makeCall(make.Ident(syms.enumSym),
2413 names.valueOf,
2414 List.of(e_class, nameVal))));
2415 JCMethodDecl valueOf = make.MethodDef(valueOfSym,
2416 make.Block(0, List.of(enum_ValueOf)));
2417 nameVal.sym = valueOf.params.head.sym;
2418 if (debugLower)
2419 System.err.println(tree.sym + ".valueOf = " + valueOf);
2420 enumDefs.append(valueOf);
2421
2422 enumDefs.appendList(otherDefs.toList());
2423 tree.defs = enumDefs.toList();
2424 }
2425 // where
2426 private MethodSymbol systemArraycopyMethod;
2427 private boolean useClone() {
2428 try {
2429 return syms.objectType.tsym.members().findFirst(names.clone) != null;
2430 }
2431 catch (CompletionFailure e) {
2432 return false;
2433 }
2434 }
2435
2436 private Name syntheticName(JCClassDecl tree, String baseName) {
2437 Name valuesName = names.fromString(target.syntheticNameChar() + baseName);
2438 while (tree.sym.members().findFirst(valuesName) != null) // avoid name clash
2439 valuesName = names.fromString(valuesName + "" + target.syntheticNameChar());
2440 return valuesName;
2441 }
2442
2443 /** Translate an enumeration constant and its initializer. */
2444 private void visitEnumConstantDef(JCVariableDecl var, int ordinal) {
2445 JCNewClass varDef = (JCNewClass)var.init;
2446 varDef.args = varDef.args.
2447 prepend(makeLit(syms.intType, ordinal)).
2448 prepend(makeLit(syms.stringType, var.name.toString()));
2449 }
2450
2451 private List<VarSymbol> recordVars(Type t) {
2452 List<VarSymbol> vars = List.nil();
2453 while (!t.hasTag(NONE)) {
2454 if (t.hasTag(CLASS)) {
2455 for (Symbol s : t.tsym.members().getSymbols(s -> s.kind == VAR && (s.flags() & RECORD) != 0)) {
2456 vars = vars.prepend((VarSymbol)s);
2457 }
2458 }
2459 t = types.supertype(t);
2460 }
2461 return vars;
2462 }
2463
2464 /** Translate a record. */
2465 private void visitRecordDef(JCClassDecl tree) {
2466 make_at(tree.pos());
2467 List<VarSymbol> vars = recordVars(tree.type);
2468 MethodHandleSymbol[] getterMethHandles = new MethodHandleSymbol[vars.size()];
2469 int index = 0;
2470 for (VarSymbol var : vars) {
2471 if (var.owner != tree.sym) {
2472 var = new VarSymbol(var.flags_field, var.name, var.type, tree.sym);
2473 }
2474 getterMethHandles[index] = var.asMethodHandle(true);
2475 index++;
2476 }
2477
2478 tree.defs = tree.defs.appendList(generateMandatedAccessors(tree));
2479 tree.defs = tree.defs.appendList(List.of(
2480 generateRecordMethod(tree, names.toString, vars, getterMethHandles),
2481 generateRecordMethod(tree, names.hashCode, vars, getterMethHandles),
2482 generateRecordMethod(tree, names.equals, vars, getterMethHandles)
2483 ));
2484 }
2485
2486 JCTree generateRecordMethod(JCClassDecl tree, Name name, List<VarSymbol> vars, MethodHandleSymbol[] getterMethHandles) {
2487 make_at(tree.pos());
2488 boolean isEquals = name == names.equals;
2489 MethodSymbol msym = lookupMethod(tree.pos(),
2490 name,
2491 tree.sym.type,
2492 isEquals ? List.of(syms.objectType) : List.nil());
2493 // compiler generated methods have the record flag set, user defined ones dont
2494 if ((msym.flags() & RECORD) != 0) {
2495 /* class java.lang.runtime.ObjectMethods provides a common bootstrap that provides a customized implementation
2496 * for methods: toString, hashCode and equals. Here we just need to generate and indy call to:
2497 * java.lang.runtime.ObjectMethods::bootstrap and provide: the record class, the record component names and
2498 * the accessors.
2499 */
2500 Name bootstrapName = names.bootstrap;
2501 LoadableConstant[] staticArgsValues = new LoadableConstant[2 + getterMethHandles.length];
2502 staticArgsValues[0] = (ClassType)tree.sym.type;
2503 String concatNames = vars.stream()
2504 .map(v -> v.name)
2505 .collect(Collectors.joining(";", "", ""));
2506 staticArgsValues[1] = LoadableConstant.String(concatNames);
2507 int index = 2;
2508 for (MethodHandleSymbol mho : getterMethHandles) {
2509 staticArgsValues[index] = mho;
2510 index++;
2511 }
2512
2513 List<Type> staticArgTypes = List.of(syms.classType,
2514 syms.stringType,
2515 new ArrayType(syms.methodHandleType, syms.arrayClass));
2516
2517 JCFieldAccess qualifier = makeIndyQualifier(syms.objectMethodsType, tree, msym,
2518 List.of(syms.methodHandleLookupType,
2519 syms.stringType,
2520 syms.typeDescriptorType).appendList(staticArgTypes),
2521 staticArgsValues, bootstrapName, name, false);
2522
2523 VarSymbol _this = new VarSymbol(SYNTHETIC, names._this, tree.sym.type, tree.sym);
2524
2525 JCMethodInvocation proxyCall;
2526 if (!isEquals) {
2527 proxyCall = make.Apply(List.nil(), qualifier, List.of(make.Ident(_this)));
2528 } else {
2529 VarSymbol o = msym.params.head;
2530 o.adr = 0;
2531 proxyCall = make.Apply(List.nil(), qualifier, List.of(make.Ident(_this), make.Ident(o)));
2532 }
2533 proxyCall.type = qualifier.type;
2534 return make.MethodDef(msym, make.Block(0, List.of(make.Return(proxyCall))));
2535 } else {
2536 return make.Block(SYNTHETIC, List.nil());
2537 }
2538 }
2539
2540 private String argsTypeSig(List<Type> typeList) {
2541 LowerSignatureGenerator sg = new LowerSignatureGenerator();
2542 sg.assembleSig(typeList);
2543 return sg.toString();
2544 }
2545
2546 /**
2547 * Signature Generation
2548 */
2549 private class LowerSignatureGenerator extends Types.SignatureGenerator {
2550
2551 /**
2552 * An output buffer for type signatures.
2553 */
2554 StringBuilder sb = new StringBuilder();
2555
2556 LowerSignatureGenerator() {
2557 super(types);
2558 }
2559
2560 @Override
2561 protected void append(char ch) {
2562 sb.append(ch);
2563 }
2564
2565 @Override
2566 protected void append(byte[] ba) {
2567 sb.append(new String(ba));
2568 }
2569
2570 @Override
2571 protected void append(Name name) {
2572 sb.append(name.toString());
2573 }
2574
2575 @Override
2576 public String toString() {
2577 return sb.toString();
2578 }
2579 }
2580
2581 /**
2582 * Creates an indy qualifier, helpful to be part of an indy invocation
2583 * @param site the site
2584 * @param tree a class declaration tree
2585 * @param msym the method symbol
2586 * @param staticArgTypes the static argument types
2587 * @param staticArgValues the static argument values
2588 * @param bootstrapName the bootstrap name to look for
2589 * @param argName normally bootstraps receives a method name as second argument, if you want that name
2590 * to be different to that of the bootstrap name pass a different name here
2591 * @param isStatic is it static or not
2592 * @return a field access tree
2593 */
2594 JCFieldAccess makeIndyQualifier(
2595 Type site,
2596 JCClassDecl tree,
2597 MethodSymbol msym,
2598 List<Type> staticArgTypes,
2599 LoadableConstant[] staticArgValues,
2600 Name bootstrapName,
2601 Name argName,
2602 boolean isStatic) {
2603 Symbol bsm = rs.resolveInternalMethod(tree.pos(), attrEnv, site,
2604 bootstrapName, staticArgTypes, List.nil());
2605
2606 MethodType indyType = msym.type.asMethodType();
2607 indyType = new MethodType(
2608 isStatic ? List.nil() : indyType.argtypes.prepend(tree.sym.type),
2609 indyType.restype,
2610 indyType.thrown,
2611 syms.methodClass
2612 );
2613 DynamicMethodSymbol dynSym = new DynamicMethodSymbol(argName,
2614 syms.noSymbol,
2615 ((MethodSymbol)bsm).asHandle(),
2616 indyType,
2617 staticArgValues);
2618 JCFieldAccess qualifier = make.Select(make.QualIdent(site.tsym), argName);
2619 qualifier.sym = dynSym;
2620 qualifier.type = msym.type.asMethodType().restype;
2621 return qualifier;
2622 }
2623
2624 public void visitMethodDef(JCMethodDecl tree) {
2625 if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) {
2626 // Add "String $enum$name, int $enum$ordinal" to the beginning of the
2627 // argument list for each constructor of an enum.
2628 JCVariableDecl nameParam = make_at(tree.pos()).
2629 Param(names.fromString(target.syntheticNameChar() +
2630 "enum" + target.syntheticNameChar() + "name"),
2631 syms.stringType, tree.sym);
2632 nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC;
2633 JCVariableDecl ordParam = make.
2634 Param(names.fromString(target.syntheticNameChar() +
2635 "enum" + target.syntheticNameChar() +
2636 "ordinal"),
2637 syms.intType, tree.sym);
2638 ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC;
2639
2640 MethodSymbol m = tree.sym;
2641 tree.params = tree.params.prepend(ordParam).prepend(nameParam);
2642
2643 m.extraParams = m.extraParams.prepend(ordParam.sym);
2644 m.extraParams = m.extraParams.prepend(nameParam.sym);
2645 Type olderasure = m.erasure(types);
2646 m.erasure_field = new MethodType(
2647 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType),
2648 olderasure.getReturnType(),
2649 olderasure.getThrownTypes(),
2650 syms.methodClass);
2651 }
2652
2653 JCMethodDecl prevMethodDef = currentMethodDef;
2654 MethodSymbol prevMethodSym = currentMethodSym;
2655 try {
2656 currentMethodDef = tree;
2657 currentMethodSym = tree.sym;
2658 visitMethodDefInternal(tree);
2659 } finally {
2660 currentMethodDef = prevMethodDef;
2661 currentMethodSym = prevMethodSym;
2662 }
2663 }
2664
2665 private void visitMethodDefInternal(JCMethodDecl tree) {
2666 if (tree.name == names.init &&
2667 (currentClass.isInner() || currentClass.isDirectlyOrIndirectlyLocal())) {
2668 // We are seeing a constructor of an inner class.
2669 MethodSymbol m = tree.sym;
2670
2671 // Push a new proxy scope for constructor parameters.
2672 // and create definitions for any this$n and proxy parameters.
2673 Map<Symbol, Symbol> prevProxies = proxies;
2674 proxies = new HashMap<>(proxies);
2675 List<VarSymbol> prevOuterThisStack = outerThisStack;
2676 List<VarSymbol> fvs = freevars(currentClass);
2677 JCVariableDecl otdef = null;
2678 if (currentClass.hasOuterInstance())
2679 otdef = outerThisDef(tree.pos, m);
2680 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER);
2681
2682 // Recursively translate result type, parameters and thrown list.
2683 tree.restype = translate(tree.restype);
2684 tree.params = translateVarDefs(tree.params);
2685 tree.thrown = translate(tree.thrown);
2686
2687 // when compiling stubs, don't process body
2688 if (tree.body == null) {
2689 result = tree;
2690 return;
2691 }
2692
2693 // Add this$n (if needed) in front of and free variables behind
2694 // constructor parameter list.
2695 tree.params = tree.params.appendList(fvdefs);
2696 if (currentClass.hasOuterInstance()) {
2697 tree.params = tree.params.prepend(otdef);
2698 }
2699
2700 // If this is an initial constructor, i.e., it does not start with
2701 // this(...), insert initializers for this$n and proxies
2702 // before (pre-1.4, after) the call to superclass constructor.
2703 JCStatement selfCall = translate(tree.body.stats.head);
2704
2705 List<JCStatement> added = List.nil();
2706 if (fvs.nonEmpty()) {
2707 List<Type> addedargtypes = List.nil();
2708 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
2709 m.capturedLocals =
2710 m.capturedLocals.prepend((VarSymbol)
2711 (proxies.get(l.head)));
2712 if (TreeInfo.isInitialConstructor(tree)) {
2713 added = added.prepend(
2714 initField(tree.body.pos, proxies.get(l.head), prevProxies.get(l.head)));
2715 }
2716 addedargtypes = addedargtypes.prepend(l.head.erasure(types));
2717 }
2718 Type olderasure = m.erasure(types);
2719 m.erasure_field = new MethodType(
2720 olderasure.getParameterTypes().appendList(addedargtypes),
2721 olderasure.getReturnType(),
2722 olderasure.getThrownTypes(),
2723 syms.methodClass);
2724 }
2725 if (currentClass.hasOuterInstance() &&
2726 TreeInfo.isInitialConstructor(tree))
2727 {
2728 added = added.prepend(initOuterThis(tree.body.pos));
2729 }
2730
2731 // pop local variables from proxy stack
2732 proxies = prevProxies;
2733
2734 // recursively translate following local statements and
2735 // combine with this- or super-call
2736 List<JCStatement> stats = translate(tree.body.stats.tail);
2737 tree.body.stats = stats.prepend(selfCall).prependList(added);
2738 outerThisStack = prevOuterThisStack;
2739 } else {
2740 Map<Symbol, Symbol> prevLambdaTranslationMap =
2741 lambdaTranslationMap;
2742 try {
2743 lambdaTranslationMap = (tree.sym.flags() & SYNTHETIC) != 0 &&
2744 tree.sym.name.startsWith(names.lambda) ?
2745 makeTranslationMap(tree) : null;
2746 super.visitMethodDef(tree);
2747 } finally {
2748 lambdaTranslationMap = prevLambdaTranslationMap;
2749 }
2750 }
2751 if (tree.name == names.init && (tree.sym.flags_field & Flags.COMPACT_RECORD_CONSTRUCTOR) != 0) {
2752 // lets find out if there is any field waiting to be initialized
2753 ListBuffer<VarSymbol> fields = new ListBuffer<>();
2754 for (Symbol sym : currentClass.getEnclosedElements()) {
2755 if (sym.kind == Kinds.Kind.VAR && ((sym.flags() & RECORD) != 0))
2756 fields.append((VarSymbol) sym);
2757 }
2758 for (VarSymbol field: fields) {
2759 if ((field.flags_field & Flags.UNINITIALIZED_FIELD) != 0) {
2760 VarSymbol param = tree.params.stream().filter(p -> p.name == field.name).findFirst().get().sym;
2761 make.at(tree.pos);
2762 tree.body.stats = tree.body.stats.append(
2763 make.Exec(
2764 make.Assign(
2765 make.Select(make.This(field.owner.erasure(types)), field),
2766 make.Ident(param)).setType(field.erasure(types))));
2767 // we don't need the flag at the field anymore
2768 field.flags_field &= ~Flags.UNINITIALIZED_FIELD;
2769 }
2770 }
2771 }
2772 result = tree;
2773 }
2774 //where
2775 private Map<Symbol, Symbol> makeTranslationMap(JCMethodDecl tree) {
2776 Map<Symbol, Symbol> translationMap = new HashMap<>();
2777 for (JCVariableDecl vd : tree.params) {
2778 Symbol p = vd.sym;
2779 if (p != p.baseSymbol()) {
2780 translationMap.put(p.baseSymbol(), p);
2781 }
2782 }
2783 return translationMap;
2784 }
2785
2786 public void visitTypeCast(JCTypeCast tree) {
2787 tree.clazz = translate(tree.clazz);
2788 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive())
2789 tree.expr = translate(tree.expr, tree.type);
2790 else
2791 tree.expr = translate(tree.expr);
2792 result = tree;
2793 }
2794
2795 public void visitNewClass(JCNewClass tree) {
2796 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
2797
2798 // Box arguments, if necessary
2799 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0;
2800 List<Type> argTypes = tree.constructor.type.getParameterTypes();
2801 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType);
2802 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement);
2803 tree.varargsElement = null;
2804
2805 // If created class is local, add free variables after
2806 // explicit constructor arguments.
2807 if (c.isDirectlyOrIndirectlyLocal()) {
2808 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
2809 }
2810
2811 // If an access constructor is used, append null as a last argument.
2812 Symbol constructor = accessConstructor(tree.pos(), tree.constructor);
2813 if (constructor != tree.constructor) {
2814 tree.args = tree.args.append(makeNull());
2815 tree.constructor = constructor;
2816 }
2817
2818 // If created class has an outer instance, and new is qualified, pass
2819 // qualifier as first argument. If new is not qualified, pass the
2820 // correct outer instance as first argument.
2821 if (c.hasOuterInstance()) {
2822 JCExpression thisArg;
2823 if (tree.encl != null) {
2824 thisArg = attr.makeNullCheck(translate(tree.encl));
2825 thisArg.type = tree.encl.type;
2826 } else if (c.isDirectlyOrIndirectlyLocal()) {
2827 // local class
2828 thisArg = makeThis(tree.pos(), c.type.getEnclosingType().tsym);
2829 } else {
2830 // nested class
2831 thisArg = makeOwnerThis(tree.pos(), c, false);
2832 }
2833 tree.args = tree.args.prepend(thisArg);
2834 }
2835 tree.encl = null;
2836
2837 // If we have an anonymous class, create its flat version, rather
2838 // than the class or interface following new.
2839 if (tree.def != null) {
2840 Map<Symbol, Symbol> prevLambdaTranslationMap = lambdaTranslationMap;
2841 try {
2842 lambdaTranslationMap = null;
2843 translate(tree.def);
2844 } finally {
2845 lambdaTranslationMap = prevLambdaTranslationMap;
2846 }
2847
2848 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym));
2849 tree.def = null;
2850 } else {
2851 tree.clazz = access(c, tree.clazz, enclOp, false);
2852 }
2853 if (tree.clazz.type.tsym == syms.objectType.tsym) {
2854 Assert.check(tree.def == null && tree.encl == null);
2855 result = makeCall(make.Ident(syms.objectsType.tsym), names.newIdentity, List.nil());
2856 } else {
2857 result = tree;
2858 }
2859 }
2860
2861 // Simplify conditionals with known constant controlling expressions.
2862 // This allows us to avoid generating supporting declarations for
2863 // the dead code, which will not be eliminated during code generation.
2864 // Note that Flow.isFalse and Flow.isTrue only return true
2865 // for constant expressions in the sense of JLS 15.27, which
2866 // are guaranteed to have no side-effects. More aggressive
2867 // constant propagation would require that we take care to
2868 // preserve possible side-effects in the condition expression.
2869
2870 // One common case is equality expressions involving a constant and null.
2871 // Since null is not a constant expression (because null cannot be
2872 // represented in the constant pool), equality checks involving null are
2873 // not captured by Flow.isTrue/isFalse.
2874 // Equality checks involving a constant and null, e.g.
2875 // "" == null
2876 // are safe to simplify as no side-effects can occur.
2877
2878 private boolean isTrue(JCTree exp) {
2879 if (exp.type.isTrue())
2880 return true;
2881 Boolean b = expValue(exp);
2882 return b == null ? false : b;
2883 }
2884 private boolean isFalse(JCTree exp) {
2885 if (exp.type.isFalse())
2886 return true;
2887 Boolean b = expValue(exp);
2888 return b == null ? false : !b;
2889 }
2890 /* look for (in)equality relations involving null.
2891 * return true - if expression is always true
2892 * false - if expression is always false
2893 * null - if expression cannot be eliminated
2894 */
2895 private Boolean expValue(JCTree exp) {
2896 while (exp.hasTag(PARENS))
2897 exp = ((JCParens)exp).expr;
2898
2899 boolean eq;
2900 switch (exp.getTag()) {
2901 case EQ: eq = true; break;
2902 case NE: eq = false; break;
2903 default:
2904 return null;
2905 }
2906
2907 // we have a JCBinary(EQ|NE)
2908 // check if we have two literals (constants or null)
2909 JCBinary b = (JCBinary)exp;
2910 if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs);
2911 if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs);
2912 return null;
2913 }
2914 private Boolean expValueIsNull(boolean eq, JCTree t) {
2915 if (t.type.hasTag(BOT)) return Boolean.valueOf(eq);
2916 if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq);
2917 return null;
2918 }
2919
2920 /** Visitor method for conditional expressions.
2921 */
2922 @Override
2923 public void visitConditional(JCConditional tree) {
2924 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
2925 if (isTrue(cond)) {
2926 result = convert(translate(tree.truepart, tree.type), tree.type);
2927 addPrunedInfo(cond);
2928 } else if (isFalse(cond)) {
2929 result = convert(translate(tree.falsepart, tree.type), tree.type);
2930 addPrunedInfo(cond);
2931 } else {
2932 // Condition is not a compile-time constant.
2933 tree.truepart = translate(tree.truepart, tree.type);
2934 tree.falsepart = translate(tree.falsepart, tree.type);
2935 result = tree;
2936 }
2937 }
2938 //where
2939 private JCExpression convert(JCExpression tree, Type pt) {
2940 if (tree.type == pt || tree.type.hasTag(BOT))
2941 return tree;
2942 JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree);
2943 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt)
2944 : pt;
2945 return result;
2946 }
2947
2948 /** Visitor method for if statements.
2949 */
2950 public void visitIf(JCIf tree) {
2951 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
2952 if (isTrue(cond)) {
2953 result = translate(tree.thenpart);
2954 addPrunedInfo(cond);
2955 } else if (isFalse(cond)) {
2956 if (tree.elsepart != null) {
2957 result = translate(tree.elsepart);
2958 } else {
2959 result = make.Skip();
2960 }
2961 addPrunedInfo(cond);
2962 } else {
2963 // Condition is not a compile-time constant.
2964 tree.thenpart = translate(tree.thenpart);
2965 tree.elsepart = translate(tree.elsepart);
2966 result = tree;
2967 }
2968 }
2969
2970 /** Visitor method for assert statements. Translate them away.
2971 */
2972 public void visitAssert(JCAssert tree) {
2973 tree.cond = translate(tree.cond, syms.booleanType);
2974 if (!tree.cond.type.isTrue()) {
2975 JCExpression cond = assertFlagTest(tree.pos());
2976 List<JCExpression> exnArgs = (tree.detail == null) ?
2977 List.nil() : List.of(translate(tree.detail));
2978 if (!tree.cond.type.isFalse()) {
2979 cond = makeBinary
2980 (AND,
2981 cond,
2982 makeUnary(NOT, tree.cond));
2983 }
2984 result =
2985 make.If(cond,
2986 make_at(tree).
2987 Throw(makeNewClass(syms.assertionErrorType, exnArgs)),
2988 null);
2989 } else {
2990 result = make.Skip();
2991 }
2992 }
2993
2994 public void visitApply(JCMethodInvocation tree) {
2995 Symbol meth = TreeInfo.symbol(tree.meth);
2996 List<Type> argtypes = meth.type.getParameterTypes();
2997 if (meth.name == names.init && meth.owner == syms.enumSym)
2998 argtypes = argtypes.tail.tail;
2999 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement);
3000 tree.varargsElement = null;
3001 Name methName = TreeInfo.name(tree.meth);
3002 if (meth.name==names.init) {
3003 // We are seeing a this(...) or super(...) constructor call.
3004 // If an access constructor is used, append null as a last argument.
3005 Symbol constructor = accessConstructor(tree.pos(), meth);
3006 if (constructor != meth) {
3007 tree.args = tree.args.append(makeNull());
3008 TreeInfo.setSymbol(tree.meth, constructor);
3009 }
3010
3011 // If we are calling a constructor of a local class, add
3012 // free variables after explicit constructor arguments.
3013 ClassSymbol c = (ClassSymbol)constructor.owner;
3014 if (c.isDirectlyOrIndirectlyLocal()) {
3015 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
3016 }
3017
3018 // If we are calling a constructor of an enum class, pass
3019 // along the name and ordinal arguments
3020 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) {
3021 List<JCVariableDecl> params = currentMethodDef.params;
3022 if (currentMethodSym.owner.hasOuterInstance())
3023 params = params.tail; // drop this$n
3024 tree.args = tree.args
3025 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal
3026 .prepend(make.Ident(params.head.sym)); // name
3027 }
3028
3029 // If we are calling a constructor of a class with an outer
3030 // instance, and the call
3031 // is qualified, pass qualifier as first argument in front of
3032 // the explicit constructor arguments. If the call
3033 // is not qualified, pass the correct outer instance as
3034 // first argument.
3035 if (c.hasOuterInstance()) {
3036 JCExpression thisArg;
3037 if (tree.meth.hasTag(SELECT)) {
3038 thisArg = attr.
3039 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected));
3040 tree.meth = make.Ident(constructor);
3041 ((JCIdent) tree.meth).name = methName;
3042 } else if (c.isDirectlyOrIndirectlyLocal() || methName == names._this){
3043 // local class or this() call
3044 thisArg = makeThis(tree.meth.pos(), c.type.getEnclosingType().tsym);
3045 } else {
3046 // super() call of nested class - never pick 'this'
3047 thisArg = makeOwnerThisN(tree.meth.pos(), c, false);
3048 }
3049 tree.args = tree.args.prepend(thisArg);
3050 }
3051 } else {
3052 // We are seeing a normal method invocation; translate this as usual.
3053 tree.meth = translate(tree.meth);
3054
3055 // If the translated method itself is an Apply tree, we are
3056 // seeing an access method invocation. In this case, append
3057 // the method arguments to the arguments of the access method.
3058 if (tree.meth.hasTag(APPLY)) {
3059 JCMethodInvocation app = (JCMethodInvocation)tree.meth;
3060 app.args = tree.args.prependList(app.args);
3061 result = app;
3062 return;
3063 }
3064 }
3065 result = tree;
3066 }
3067
3068 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) {
3069 List<JCExpression> args = _args;
3070 if (parameters.isEmpty()) return args;
3071 boolean anyChanges = false;
3072 ListBuffer<JCExpression> result = new ListBuffer<>();
3073 while (parameters.tail.nonEmpty()) {
3074 JCExpression arg = translate(args.head, parameters.head);
3075 anyChanges |= (arg != args.head);
3076 result.append(arg);
3077 args = args.tail;
3078 parameters = parameters.tail;
3079 }
3080 Type parameter = parameters.head;
3081 if (varargsElement != null) {
3082 anyChanges = true;
3083 ListBuffer<JCExpression> elems = new ListBuffer<>();
3084 while (args.nonEmpty()) {
3085 JCExpression arg = translate(args.head, varargsElement);
3086 elems.append(arg);
3087 args = args.tail;
3088 }
3089 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement),
3090 List.nil(),
3091 elems.toList());
3092 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass);
3093 result.append(boxedArgs);
3094 } else {
3095 if (args.length() != 1) throw new AssertionError(args);
3096 JCExpression arg = translate(args.head, parameter);
3097 anyChanges |= (arg != args.head);
3098 result.append(arg);
3099 if (!anyChanges) return _args;
3100 }
3101 return result.toList();
3102 }
3103
3104 /** Apply primitive value/reference conversions as needed */
3105 @SuppressWarnings("unchecked")
3106 <T extends JCExpression> T applyPrimitiveConversionsAsNeeded(T tree, Type type) {
3107 boolean haveValue = tree.type.isPrimitiveClass();
3108 if (haveValue == type.isPrimitiveClass())
3109 return tree;
3110 // For narrowing conversion, insert a cast which should trigger a null check
3111 // For widening conversions, insert a cast if emitting a unified class file.
3112 return (T) make.TypeCast(type, tree);
3113
3114 }
3115
3116
3117
3118 /** Expand a boxing or unboxing conversion if needed. */
3119 @SuppressWarnings("unchecked") // XXX unchecked
3120 <T extends JCExpression> T boxIfNeeded(T tree, Type type) {
3121 boolean havePrimitive = tree.type.isPrimitive();
3122 if (havePrimitive == type.isPrimitive())
3123 return tree;
3124 if (havePrimitive) {
3125 Type unboxedTarget = types.unboxedType(type);
3126 if (!unboxedTarget.hasTag(NONE)) {
3127 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89;
3128 tree.type = unboxedTarget.constType(tree.type.constValue());
3129 return (T)boxPrimitive(tree, types.erasure(type));
3130 } else {
3131 tree = (T)boxPrimitive(tree);
3132 }
3133 } else {
3134 tree = (T)unbox(tree, type);
3135 }
3136 return tree;
3137 }
3138
3139 /** Box up a single primitive expression. */
3140 JCExpression boxPrimitive(JCExpression tree) {
3141 return boxPrimitive(tree, types.boxedClass(tree.type).type);
3142 }
3143
3144 /** Box up a single primitive expression. */
3145 JCExpression boxPrimitive(JCExpression tree, Type box) {
3146 make_at(tree.pos());
3147 Symbol valueOfSym = lookupMethod(tree.pos(),
3148 names.valueOf,
3149 box,
3150 List.<Type>nil()
3151 .prepend(tree.type));
3152 return make.App(make.QualIdent(valueOfSym), List.of(tree));
3153 }
3154
3155 /** Unbox an object to a primitive value. */
3156 JCExpression unbox(JCExpression tree, Type primitive) {
3157 Type unboxedType = types.unboxedType(tree.type);
3158 if (unboxedType.hasTag(NONE)) {
3159 unboxedType = primitive;
3160 if (!unboxedType.isPrimitive())
3161 throw new AssertionError(unboxedType);
3162 make_at(tree.pos());
3163 tree = make.TypeCast(types.boxedClass(unboxedType).type, tree);
3164 } else {
3165 // There must be a conversion from unboxedType to primitive.
3166 if (!types.isSubtype(unboxedType, primitive))
3167 throw new AssertionError(tree);
3168 }
3169 make_at(tree.pos());
3170 Symbol valueSym = lookupMethod(tree.pos(),
3171 unboxedType.tsym.name.append(names.Value), // x.intValue()
3172 tree.type,
3173 List.nil());
3174 return make.App(make.Select(tree, valueSym));
3175 }
3176
3177 /** Visitor method for parenthesized expressions.
3178 * If the subexpression has changed, omit the parens.
3179 */
3180 public void visitParens(JCParens tree) {
3181 JCTree expr = translate(tree.expr);
3182 result = ((expr == tree.expr) ? tree : expr);
3183 }
3184
3185 public void visitIndexed(JCArrayAccess tree) {
3186 tree.indexed = translate(tree.indexed);
3187 tree.index = translate(tree.index, syms.intType);
3188 result = tree;
3189 }
3190
3191 public void visitAssign(JCAssign tree) {
3192 tree.lhs = translate(tree.lhs, tree);
3193 tree.rhs = translate(tree.rhs, tree.lhs.type);
3194
3195 // If translated left hand side is an Apply, we are
3196 // seeing an access method invocation. In this case, append
3197 // right hand side as last argument of the access method.
3198 if (tree.lhs.hasTag(APPLY)) {
3199 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3200 app.args = List.of(tree.rhs).prependList(app.args);
3201 result = app;
3202 } else {
3203 result = tree;
3204 }
3205 }
3206
3207 public void visitAssignop(final JCAssignOp tree) {
3208 final boolean boxingReq = !tree.lhs.type.isPrimitive() &&
3209 tree.operator.type.getReturnType().isPrimitive();
3210
3211 AssignopDependencyScanner depScanner = new AssignopDependencyScanner(tree);
3212 depScanner.scan(tree.rhs);
3213
3214 if (boxingReq || depScanner.dependencyFound) {
3215 // boxing required; need to rewrite as x = (unbox typeof x)(x op y);
3216 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y)
3217 // (but without recomputing x)
3218 JCTree newTree = abstractLval(tree.lhs, lhs -> {
3219 Tag newTag = tree.getTag().noAssignOp();
3220 // Erasure (TransTypes) can change the type of
3221 // tree.lhs. However, we can still get the
3222 // unerased type of tree.lhs as it is stored
3223 // in tree.type in Attr.
3224 OperatorSymbol newOperator = operators.resolveBinary(tree,
3225 newTag,
3226 tree.type,
3227 tree.rhs.type);
3228 //Need to use the "lhs" at two places, once on the future left hand side
3229 //and once in the future binary operator. But further processing may change
3230 //the components of the tree in place (see visitSelect for e.g. <Class>.super.<ident>),
3231 //so cloning the tree to avoid interference between the uses:
3232 JCExpression expr = (JCExpression) lhs.clone();
3233 if (expr.type != tree.type)
3234 expr = make.TypeCast(tree.type, expr);
3235 JCBinary opResult = make.Binary(newTag, expr, tree.rhs);
3236 opResult.operator = newOperator;
3237 opResult.type = newOperator.type.getReturnType();
3238 JCExpression newRhs = boxingReq ?
3239 make.TypeCast(types.unboxedType(tree.type), opResult) :
3240 opResult;
3241 return make.Assign(lhs, newRhs).setType(tree.type);
3242 });
3243 result = translate(newTree);
3244 return;
3245 }
3246 tree.lhs = translate(tree.lhs, tree);
3247 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
3248
3249 // If translated left hand side is an Apply, we are
3250 // seeing an access method invocation. In this case, append
3251 // right hand side as last argument of the access method.
3252 if (tree.lhs.hasTag(APPLY)) {
3253 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3254 // if operation is a += on strings,
3255 // make sure to convert argument to string
3256 JCExpression rhs = tree.operator.opcode == string_add
3257 ? makeString(tree.rhs)
3258 : tree.rhs;
3259 app.args = List.of(rhs).prependList(app.args);
3260 result = app;
3261 } else {
3262 result = tree;
3263 }
3264 }
3265
3266 class AssignopDependencyScanner extends TreeScanner {
3267
3268 Symbol sym;
3269 boolean dependencyFound = false;
3270
3271 AssignopDependencyScanner(JCAssignOp tree) {
3272 this.sym = TreeInfo.symbol(tree.lhs);
3273 }
3274
3275 @Override
3276 public void scan(JCTree tree) {
3277 if (tree != null && sym != null) {
3278 tree.accept(this);
3279 }
3280 }
3281
3282 @Override
3283 public void visitAssignop(JCAssignOp tree) {
3284 if (TreeInfo.symbol(tree.lhs) == sym) {
3285 dependencyFound = true;
3286 return;
3287 }
3288 super.visitAssignop(tree);
3289 }
3290
3291 @Override
3292 public void visitUnary(JCUnary tree) {
3293 if (TreeInfo.symbol(tree.arg) == sym) {
3294 dependencyFound = true;
3295 return;
3296 }
3297 super.visitUnary(tree);
3298 }
3299 }
3300
3301 /** Lower a tree of the form e++ or e-- where e is an object type */
3302 JCExpression lowerBoxedPostop(final JCUnary tree) {
3303 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2
3304 // or
3305 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2
3306 // where OP is += or -=
3307 final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST);
3308 return abstractLval(tree.arg, tmp1 -> abstractRval(tmp1, tree.arg.type, tmp2 -> {
3309 Tag opcode = (tree.hasTag(POSTINC))
3310 ? PLUS_ASG : MINUS_ASG;
3311 //"tmp1" and "tmp2" may refer to the same instance
3312 //(for e.g. <Class>.super.<ident>). But further processing may
3313 //change the components of the tree in place (see visitSelect),
3314 //so cloning the tree to avoid interference between the two uses:
3315 JCExpression lhs = (JCExpression)tmp1.clone();
3316 lhs = cast
3317 ? make.TypeCast(tree.arg.type, lhs)
3318 : lhs;
3319 JCExpression update = makeAssignop(opcode,
3320 lhs,
3321 make.Literal(1));
3322 return makeComma(update, tmp2);
3323 }));
3324 }
3325
3326 public void visitUnary(JCUnary tree) {
3327 boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp();
3328 if (isUpdateOperator && !tree.arg.type.isPrimitive()) {
3329 switch(tree.getTag()) {
3330 case PREINC: // ++ e
3331 // translate to e += 1
3332 case PREDEC: // -- e
3333 // translate to e -= 1
3334 {
3335 JCTree.Tag opcode = (tree.hasTag(PREINC))
3336 ? PLUS_ASG : MINUS_ASG;
3337 JCAssignOp newTree = makeAssignop(opcode,
3338 tree.arg,
3339 make.Literal(1));
3340 result = translate(newTree, tree.type);
3341 return;
3342 }
3343 case POSTINC: // e ++
3344 case POSTDEC: // e --
3345 {
3346 result = translate(lowerBoxedPostop(tree), tree.type);
3347 return;
3348 }
3349 }
3350 throw new AssertionError(tree);
3351 }
3352
3353 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type);
3354
3355 if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) {
3356 tree.type = cfolder.fold1(bool_not, tree.arg.type);
3357 }
3358
3359 // If translated left hand side is an Apply, we are
3360 // seeing an access method invocation. In this case, return
3361 // that access method invocation as result.
3362 if (isUpdateOperator && tree.arg.hasTag(APPLY)) {
3363 result = tree.arg;
3364 } else {
3365 result = tree;
3366 }
3367 }
3368
3369 public void visitBinary(JCBinary tree) {
3370 List<Type> formals = tree.operator.type.getParameterTypes();
3371 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head);
3372 switch (tree.getTag()) {
3373 case OR:
3374 if (isTrue(lhs)) {
3375 result = lhs;
3376 return;
3377 }
3378 if (isFalse(lhs)) {
3379 result = translate(tree.rhs, formals.tail.head);
3380 return;
3381 }
3382 break;
3383 case AND:
3384 if (isFalse(lhs)) {
3385 result = lhs;
3386 return;
3387 }
3388 if (isTrue(lhs)) {
3389 result = translate(tree.rhs, formals.tail.head);
3390 return;
3391 }
3392 break;
3393 }
3394 tree.rhs = translate(tree.rhs, formals.tail.head);
3395 result = tree;
3396 }
3397
3398 public void visitIdent(JCIdent tree) {
3399 result = access(tree.sym, tree, enclOp, false);
3400 }
3401
3402 /** Translate away the foreach loop. */
3403 public void visitForeachLoop(JCEnhancedForLoop tree) {
3404 if (types.elemtype(tree.expr.type) == null)
3405 visitIterableForeachLoop(tree);
3406 else
3407 visitArrayForeachLoop(tree);
3408 }
3409 // where
3410 /**
3411 * A statement of the form
3412 *
3413 * <pre>
3414 * for ( T v : arrayexpr ) stmt;
3415 * </pre>
3416 *
3417 * (where arrayexpr is of an array type) gets translated to
3418 *
3419 * <pre>{@code
3420 * for ( { arraytype #arr = arrayexpr;
3421 * int #len = array.length;
3422 * int #i = 0; };
3423 * #i < #len; i$++ ) {
3424 * T v = arr$[#i];
3425 * stmt;
3426 * }
3427 * }</pre>
3428 *
3429 * where #arr, #len, and #i are freshly named synthetic local variables.
3430 */
3431 private void visitArrayForeachLoop(JCEnhancedForLoop tree) {
3432 make_at(tree.expr.pos());
3433 VarSymbol arraycache = new VarSymbol(SYNTHETIC,
3434 names.fromString("arr" + target.syntheticNameChar()),
3435 tree.expr.type,
3436 currentMethodSym);
3437 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr);
3438 VarSymbol lencache = new VarSymbol(SYNTHETIC,
3439 names.fromString("len" + target.syntheticNameChar()),
3440 syms.intType,
3441 currentMethodSym);
3442 JCStatement lencachedef = make.
3443 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar));
3444 VarSymbol index = new VarSymbol(SYNTHETIC,
3445 names.fromString("i" + target.syntheticNameChar()),
3446 syms.intType,
3447 currentMethodSym);
3448
3449 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0));
3450 indexdef.init.type = indexdef.type = syms.intType.constType(0);
3451
3452 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef);
3453 JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache));
3454
3455 JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index)));
3456
3457 Type elemtype = types.elemtype(tree.expr.type);
3458 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache),
3459 make.Ident(index)).setType(elemtype);
3460 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods,
3461 tree.var.name,
3462 tree.var.vartype,
3463 loopvarinit).setType(tree.var.type);
3464 loopvardef.sym = tree.var.sym;
3465 JCBlock body = make.
3466 Block(0, List.of(loopvardef, tree.body));
3467
3468 result = translate(make.
3469 ForLoop(loopinit,
3470 cond,
3471 List.of(step),
3472 body));
3473 patchTargets(body, tree, result);
3474 }
3475 /** Patch up break and continue targets. */
3476 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) {
3477 class Patcher extends TreeScanner {
3478 public void visitBreak(JCBreak tree) {
3479 if (tree.target == src)
3480 tree.target = dest;
3481 }
3482 public void visitYield(JCYield tree) {
3483 if (tree.target == src)
3484 tree.target = dest;
3485 scan(tree.value);
3486 }
3487 public void visitContinue(JCContinue tree) {
3488 if (tree.target == src)
3489 tree.target = dest;
3490 }
3491 public void visitClassDef(JCClassDecl tree) {}
3492 }
3493 new Patcher().scan(body);
3494 }
3495 /**
3496 * A statement of the form
3497 *
3498 * <pre>
3499 * for ( T v : coll ) stmt ;
3500 * </pre>
3501 *
3502 * (where coll implements {@code Iterable<? extends T>}) gets translated to
3503 *
3504 * <pre>{@code
3505 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) {
3506 * T v = (T) #i.next();
3507 * stmt;
3508 * }
3509 * }</pre>
3510 *
3511 * where #i is a freshly named synthetic local variable.
3512 */
3513 private void visitIterableForeachLoop(JCEnhancedForLoop tree) {
3514 make_at(tree.expr.pos());
3515 Type iteratorTarget = syms.objectType;
3516 Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type.referenceProjectionOrSelf()),
3517 syms.iterableType.tsym);
3518 if (iterableType.getTypeArguments().nonEmpty())
3519 iteratorTarget = types.erasure(iterableType.getTypeArguments().head);
3520 Type eType = types.skipTypeVars(tree.expr.type, false);
3521 tree.expr.type = types.erasure(eType);
3522 if (eType.isCompound())
3523 tree.expr = make.TypeCast(types.erasure(iterableType), tree.expr);
3524 Symbol iterator = lookupMethod(tree.expr.pos(),
3525 names.iterator,
3526 eType,
3527 List.nil());
3528 VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()),
3529 types.erasure(types.asSuper(iterator.type.getReturnType().referenceProjectionOrSelf(), syms.iteratorType.tsym)),
3530 currentMethodSym);
3531
3532 JCStatement init = make.
3533 VarDef(itvar, make.App(make.Select(tree.expr, iterator)
3534 .setType(types.erasure(iterator.type))));
3535
3536 Symbol hasNext = lookupMethod(tree.expr.pos(),
3537 names.hasNext,
3538 itvar.type,
3539 List.nil());
3540 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext));
3541 Symbol next = lookupMethod(tree.expr.pos(),
3542 names.next,
3543 itvar.type,
3544 List.nil());
3545 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next));
3546 if (tree.var.type.isPrimitive())
3547 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit);
3548 else
3549 vardefinit = make.TypeCast(tree.var.type, vardefinit);
3550 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods,
3551 tree.var.name,
3552 tree.var.vartype,
3553 vardefinit).setType(tree.var.type);
3554 indexDef.sym = tree.var.sym;
3555 JCBlock body = make.Block(0, List.of(indexDef, tree.body));
3556 body.endpos = TreeInfo.endPos(tree.body);
3557 result = translate(make.
3558 ForLoop(List.of(init),
3559 cond,
3560 List.nil(),
3561 body));
3562 patchTargets(body, tree, result);
3563 }
3564
3565 public void visitVarDef(JCVariableDecl tree) {
3566 MethodSymbol oldMethodSym = currentMethodSym;
3567 tree.mods = translate(tree.mods);
3568 tree.vartype = translate(tree.vartype);
3569 if (currentMethodSym == null) {
3570 // A class or instance field initializer.
3571 currentMethodSym =
3572 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK,
3573 names.empty, null,
3574 currentClass);
3575 }
3576 if (tree.init != null) tree.init = translate(tree.init, tree.type);
3577 result = tree;
3578 currentMethodSym = oldMethodSym;
3579 }
3580
3581 public void visitBlock(JCBlock tree) {
3582 MethodSymbol oldMethodSym = currentMethodSym;
3583 if (currentMethodSym == null) {
3584 // Block is a static or instance initializer.
3585 currentMethodSym =
3586 new MethodSymbol(tree.flags | BLOCK,
3587 names.empty, null,
3588 currentClass);
3589 }
3590 super.visitBlock(tree);
3591 currentMethodSym = oldMethodSym;
3592 }
3593
3594 public void visitDoLoop(JCDoWhileLoop tree) {
3595 tree.body = translate(tree.body);
3596 tree.cond = translate(tree.cond, syms.booleanType);
3597 result = tree;
3598 }
3599
3600 public void visitWhileLoop(JCWhileLoop tree) {
3601 tree.cond = translate(tree.cond, syms.booleanType);
3602 tree.body = translate(tree.body);
3603 result = tree;
3604 }
3605
3606 public void visitWithField(JCWithField tree) {
3607 Type fieldType = tree.field.type;
3608 tree.field = translate(tree.field, tree);
3609 tree.value = translate(tree.value, fieldType); // important to use pre-translation type.
3610
3611 // If translated field is an Apply, we are
3612 // seeing an access method invocation. In this case, append
3613 // right hand side as last argument of the access method.
3614 if (tree.field.hasTag(APPLY)) {
3615 JCMethodInvocation app = (JCMethodInvocation) tree.field;
3616 app.args = List.of(tree.value).prependList(app.args);
3617 result = app;
3618 } else {
3619 result = tree;
3620 }
3621 }
3622
3623 public void visitForLoop(JCForLoop tree) {
3624 tree.init = translate(tree.init);
3625 if (tree.cond != null)
3626 tree.cond = translate(tree.cond, syms.booleanType);
3627 tree.step = translate(tree.step);
3628 tree.body = translate(tree.body);
3629 result = tree;
3630 }
3631
3632 public void visitReturn(JCReturn tree) {
3633 if (tree.expr != null)
3634 tree.expr = translate(tree.expr,
3635 types.erasure(currentMethodDef
3636 .restype.type));
3637 result = tree;
3638 }
3639
3640 public void visitSwitch(JCSwitch tree) {
3641 List<JCCase> cases = tree.patternSwitch ? addDefaultIfNeeded(tree.cases) : tree.cases;
3642 handleSwitch(tree, tree.selector, cases);
3643 }
3644
3645 @Override
3646 public void visitSwitchExpression(JCSwitchExpression tree) {
3647 List<JCCase> cases = addDefaultIfNeeded(tree.cases);
3648 handleSwitch(tree, tree.selector, cases);
3649 }
3650
3651 private List<JCCase> addDefaultIfNeeded(List<JCCase> cases) {
3652 if (cases.stream().flatMap(c -> c.labels.stream()).noneMatch(p -> p.hasTag(Tag.DEFAULTCASELABEL))) {
3653 JCThrow thr = make.Throw(makeNewClass(syms.incompatibleClassChangeErrorType,
3654 List.nil()));
3655 JCCase c = make.Case(JCCase.STATEMENT, List.of(make.DefaultCaseLabel()), List.of(thr), null);
3656 cases = cases.prepend(c);
3657 }
3658
3659 return cases;
3660 }
3661
3662 private void handleSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
3663 //expand multiple label cases:
3664 ListBuffer<JCCase> convertedCases = new ListBuffer<>();
3665
3666 for (JCCase c : cases) {
3667 switch (c.labels.size()) {
3668 case 0: //default
3669 case 1: //single label
3670 convertedCases.append(c);
3671 break;
3672 default: //multiple labels, expand:
3673 //case C1, C2, C3: ...
3674 //=>
3675 //case C1:
3676 //case C2:
3677 //case C3: ...
3678 List<JCCaseLabel> patterns = c.labels;
3679 while (patterns.tail.nonEmpty()) {
3680 convertedCases.append(make_at(c.pos()).Case(JCCase.STATEMENT,
3681 List.of(patterns.head),
3682 List.nil(),
3683 null));
3684 patterns = patterns.tail;
3685 }
3686 c.labels = patterns;
3687 convertedCases.append(c);
3688 break;
3689 }
3690 }
3691
3692 for (JCCase c : convertedCases) {
3693 if (c.caseKind == JCCase.RULE && c.completesNormally) {
3694 JCBreak b = make.at(TreeInfo.endPos(c.stats.last())).Break(null);
3695 b.target = tree;
3696 c.stats = c.stats.append(b);
3697 }
3698 }
3699
3700 cases = convertedCases.toList();
3701
3702 Type selsuper = types.supertype(selector.type);
3703 boolean enumSwitch = selsuper != null &&
3704 (selector.type.tsym.flags() & ENUM) != 0;
3705 boolean stringSwitch = selsuper != null &&
3706 types.isSameType(selector.type, syms.stringType);
3707 boolean boxedSwitch = !enumSwitch && !stringSwitch && !selector.type.isPrimitive();
3708 selector = translate(selector, selector.type);
3709 cases = translateCases(cases);
3710 if (tree.hasTag(SWITCH)) {
3711 ((JCSwitch) tree).selector = selector;
3712 ((JCSwitch) tree).cases = cases;
3713 } else if (tree.hasTag(SWITCH_EXPRESSION)) {
3714 ((JCSwitchExpression) tree).selector = selector;
3715 ((JCSwitchExpression) tree).cases = cases;
3716 } else {
3717 Assert.error();
3718 }
3719 if (enumSwitch) {
3720 result = visitEnumSwitch(tree, selector, cases);
3721 } else if (stringSwitch) {
3722 result = visitStringSwitch(tree, selector, cases);
3723 } else if (boxedSwitch) {
3724 //An switch over boxed primitive. Pattern matching switches are already translated
3725 //by TransPatterns, so all non-primitive types are only boxed primitives:
3726 result = visitBoxedPrimitiveSwitch(tree, selector, cases);
3727 } else {
3728 result = tree;
3729 }
3730 }
3731
3732 public JCTree visitEnumSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
3733 TypeSymbol enumSym = selector.type.tsym;
3734 EnumMapping map = mapForEnum(tree.pos(), enumSym);
3735 make_at(tree.pos());
3736 Symbol ordinalMethod = lookupMethod(tree.pos(),
3737 names.ordinal,
3738 selector.type,
3739 List.nil());
3740 JCExpression newSelector;
3741
3742 if (cases.stream().anyMatch(c -> TreeInfo.isNull(c.labels.head))) {
3743 //for enum switches with case null, do:
3744 //switch ($selector != null ? $mapVar[$selector.ordinal()] : -1) {...}
3745 //replacing case null with case -1:
3746 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
3747 names.fromString("s" + tree.pos + this.target.syntheticNameChar()),
3748 selector.type,
3749 currentMethodSym);
3750 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type);
3751 newSelector = make.Indexed(map.mapVar,
3752 make.App(make.Select(make.Ident(dollar_s),
3753 ordinalMethod)));
3754 newSelector =
3755 make.LetExpr(List.of(var),
3756 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()),
3757 newSelector,
3758 makeLit(syms.intType, -1))
3759 .setType(newSelector.type))
3760 .setType(newSelector.type);
3761 } else {
3762 newSelector = make.Indexed(map.mapVar,
3763 make.App(make.Select(selector,
3764 ordinalMethod)));
3765 }
3766 ListBuffer<JCCase> newCases = new ListBuffer<>();
3767 for (JCCase c : cases) {
3768 if (c.labels.head.isExpression()) {
3769 JCExpression pat;
3770 if (TreeInfo.isNull(c.labels.head)) {
3771 pat = makeLit(syms.intType, -1);
3772 } else {
3773 VarSymbol label = (VarSymbol)TreeInfo.symbol((JCExpression) c.labels.head);
3774 pat = map.forConstant(label);
3775 }
3776 newCases.append(make.Case(JCCase.STATEMENT, List.of(pat), c.stats, null));
3777 } else {
3778 newCases.append(c);
3779 }
3780 }
3781 JCTree enumSwitch;
3782 if (tree.hasTag(SWITCH)) {
3783 enumSwitch = make.Switch(newSelector, newCases.toList());
3784 } else if (tree.hasTag(SWITCH_EXPRESSION)) {
3785 enumSwitch = make.SwitchExpression(newSelector, newCases.toList());
3786 enumSwitch.setType(tree.type);
3787 } else {
3788 Assert.error();
3789 throw new AssertionError();
3790 }
3791 patchTargets(enumSwitch, tree, enumSwitch);
3792 return enumSwitch;
3793 }
3794
3795 public JCTree visitStringSwitch(JCTree tree, JCExpression selector, List<JCCase> caseList) {
3796 int alternatives = caseList.size();
3797
3798 if (alternatives == 0) { // Strange but legal possibility (only legal for switch statement)
3799 return make.at(tree.pos()).Exec(attr.makeNullCheck(selector));
3800 } else {
3801 /*
3802 * The general approach used is to translate a single
3803 * string switch statement into a series of two chained
3804 * switch statements: the first a synthesized statement
3805 * switching on the argument string's hash value and
3806 * computing a string's position in the list of original
3807 * case labels, if any, followed by a second switch on the
3808 * computed integer value. The second switch has the same
3809 * code structure as the original string switch statement
3810 * except that the string case labels are replaced with
3811 * positional integer constants starting at 0.
3812 *
3813 * The first switch statement can be thought of as an
3814 * inlined map from strings to their position in the case
3815 * label list. An alternate implementation would use an
3816 * actual Map for this purpose, as done for enum switches.
3817 *
3818 * With some additional effort, it would be possible to
3819 * use a single switch statement on the hash code of the
3820 * argument, but care would need to be taken to preserve
3821 * the proper control flow in the presence of hash
3822 * collisions and other complications, such as
3823 * fallthroughs. Switch statements with one or two
3824 * alternatives could also be specially translated into
3825 * if-then statements to omit the computation of the hash
3826 * code.
3827 *
3828 * The generated code assumes that the hashing algorithm
3829 * of String is the same in the compilation environment as
3830 * in the environment the code will run in. The string
3831 * hashing algorithm in the SE JDK has been unchanged
3832 * since at least JDK 1.2. Since the algorithm has been
3833 * specified since that release as well, it is very
3834 * unlikely to be changed in the future.
3835 *
3836 * Different hashing algorithms, such as the length of the
3837 * strings or a perfect hashing algorithm over the
3838 * particular set of case labels, could potentially be
3839 * used instead of String.hashCode.
3840 */
3841
3842 ListBuffer<JCStatement> stmtList = new ListBuffer<>();
3843
3844 // Map from String case labels to their original position in
3845 // the list of case labels.
3846 Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f);
3847
3848 // Map of hash codes to the string case labels having that hashCode.
3849 Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f);
3850
3851 int casePosition = 0;
3852 JCCase nullCase = null;
3853 int nullCaseLabel = -1;
3854
3855 for(JCCase oneCase : caseList) {
3856 if (oneCase.labels.head.isExpression()) {
3857 if (TreeInfo.isNull(oneCase.labels.head)) {
3858 nullCase = oneCase;
3859 nullCaseLabel = casePosition;
3860 } else {
3861 JCExpression expression = (JCExpression) oneCase.labels.head;
3862 String labelExpr = (String) expression.type.constValue();
3863 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition);
3864 Assert.checkNull(mapping);
3865 int hashCode = labelExpr.hashCode();
3866
3867 Set<String> stringSet = hashToString.get(hashCode);
3868 if (stringSet == null) {
3869 stringSet = new LinkedHashSet<>(1, 1.0f);
3870 stringSet.add(labelExpr);
3871 hashToString.put(hashCode, stringSet);
3872 } else {
3873 boolean added = stringSet.add(labelExpr);
3874 Assert.check(added);
3875 }
3876 }
3877 }
3878 casePosition++;
3879 }
3880
3881 // Synthesize a switch statement that has the effect of
3882 // mapping from a string to the integer position of that
3883 // string in the list of case labels. This is done by
3884 // switching on the hashCode of the string followed by an
3885 // if-then-else chain comparing the input for equality
3886 // with all the case labels having that hash value.
3887
3888 /*
3889 * s$ = top of stack;
3890 * tmp$ = -1;
3891 * switch($s.hashCode()) {
3892 * case caseLabel.hashCode:
3893 * if (s$.equals("caseLabel_1")
3894 * tmp$ = caseLabelToPosition("caseLabel_1");
3895 * else if (s$.equals("caseLabel_2"))
3896 * tmp$ = caseLabelToPosition("caseLabel_2");
3897 * ...
3898 * break;
3899 * ...
3900 * }
3901 */
3902
3903 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
3904 names.fromString("s" + tree.pos + target.syntheticNameChar()),
3905 syms.stringType,
3906 currentMethodSym);
3907 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type));
3908
3909 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC,
3910 names.fromString("tmp" + tree.pos + target.syntheticNameChar()),
3911 syms.intType,
3912 currentMethodSym);
3913 JCVariableDecl dollar_tmp_def =
3914 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type);
3915 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType;
3916 stmtList.append(dollar_tmp_def);
3917 ListBuffer<JCCase> caseBuffer = new ListBuffer<>();
3918 // hashCode will trigger nullcheck on original switch expression
3919 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s),
3920 names.hashCode,
3921 List.nil()).setType(syms.intType);
3922 JCSwitch switch1 = make.Switch(hashCodeCall,
3923 caseBuffer.toList());
3924 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) {
3925 int hashCode = entry.getKey();
3926 Set<String> stringsWithHashCode = entry.getValue();
3927 Assert.check(stringsWithHashCode.size() >= 1);
3928
3929 JCStatement elsepart = null;
3930 for(String caseLabel : stringsWithHashCode ) {
3931 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s),
3932 names.equals,
3933 List.of(make.Literal(caseLabel)));
3934 elsepart = make.If(stringEqualsCall,
3935 make.Exec(make.Assign(make.Ident(dollar_tmp),
3936 make.Literal(caseLabelToPosition.get(caseLabel))).
3937 setType(dollar_tmp.type)),
3938 elsepart);
3939 }
3940
3941 ListBuffer<JCStatement> lb = new ListBuffer<>();
3942 JCBreak breakStmt = make.Break(null);
3943 breakStmt.target = switch1;
3944 lb.append(elsepart).append(breakStmt);
3945
3946 caseBuffer.append(make.Case(JCCase.STATEMENT, List.of(make.Literal(hashCode)), lb.toList(), null));
3947 }
3948
3949 switch1.cases = caseBuffer.toList();
3950
3951 if (nullCase != null) {
3952 stmtList.append(make.If(makeBinary(NE, make.Ident(dollar_s), makeNull()), switch1, make.Exec(make.Assign(make.Ident(dollar_tmp),
3953 make.Literal(nullCaseLabel)).
3954 setType(dollar_tmp.type))).setType(syms.intType));
3955 } else {
3956 stmtList.append(switch1);
3957 }
3958
3959 // Make isomorphic switch tree replacing string labels
3960 // with corresponding integer ones from the label to
3961 // position map.
3962
3963 ListBuffer<JCCase> lb = new ListBuffer<>();
3964 for(JCCase oneCase : caseList ) {
3965 boolean isDefault = !oneCase.labels.head.isExpression();
3966 JCCaseLabel caseExpr;
3967 if (isDefault)
3968 caseExpr = null;
3969 else if (oneCase == nullCase) {
3970 caseExpr = make.Literal(nullCaseLabel);
3971 } else {
3972 caseExpr = make.Literal(caseLabelToPosition.get((String)TreeInfo.skipParens((JCExpression) oneCase.labels.head).
3973 type.constValue()));
3974 }
3975
3976 lb.append(make.Case(JCCase.STATEMENT, caseExpr == null ? List.of(make.DefaultCaseLabel()) : List.of(caseExpr),
3977 oneCase.stats, null));
3978 }
3979
3980 if (tree.hasTag(SWITCH)) {
3981 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList());
3982 // Rewire up old unlabeled break statements to the
3983 // replacement switch being created.
3984 patchTargets(switch2, tree, switch2);
3985
3986 stmtList.append(switch2);
3987
3988 JCBlock res = make.Block(0L, stmtList.toList());
3989 res.endpos = TreeInfo.endPos(tree);
3990 return res;
3991 } else {
3992 JCSwitchExpression switch2 = make.SwitchExpression(make.Ident(dollar_tmp), lb.toList());
3993
3994 // Rewire up old unlabeled break statements to the
3995 // replacement switch being created.
3996 patchTargets(switch2, tree, switch2);
3997
3998 switch2.setType(tree.type);
3999
4000 LetExpr res = make.LetExpr(stmtList.toList(), switch2);
4001
4002 res.needsCond = true;
4003 res.setType(tree.type);
4004
4005 return res;
4006 }
4007 }
4008 }
4009
4010 private JCTree visitBoxedPrimitiveSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
4011 JCExpression newSelector;
4012
4013 if (cases.stream().anyMatch(c -> TreeInfo.isNull(c.labels.head))) {
4014 //a switch over a boxed primitive, with a null case. Pick two constants that are
4015 //not used by any branch in the case (c1 and c2), close to other constants that are
4016 //used in the switch. Then do:
4017 //switch ($selector != null ? $selector != c1 ? $selector : c2 : c1) {...}
4018 //replacing case null with case c1
4019 Set<Integer> constants = new LinkedHashSet<>();
4020 JCCase nullCase = null;
4021
4022 for (JCCase c : cases) {
4023 if (TreeInfo.isNull(c.labels.head)) {
4024 nullCase = c;
4025 } else if (!c.labels.head.hasTag(DEFAULTCASELABEL)) {
4026 constants.add((int) c.labels.head.type.constValue());
4027 }
4028 }
4029
4030 Assert.checkNonNull(nullCase);
4031
4032 int nullValue = constants.isEmpty() ? 0 : constants.iterator().next();
4033
4034 while (constants.contains(nullValue)) nullValue++;
4035
4036 constants.add(nullValue);
4037 nullCase.labels.head = makeLit(syms.intType, nullValue);
4038
4039 int replacementValue = nullValue;
4040
4041 while (constants.contains(replacementValue)) replacementValue++;
4042
4043 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
4044 names.fromString("s" + tree.pos + this.target.syntheticNameChar()),
4045 selector.type,
4046 currentMethodSym);
4047 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type);
4048 JCExpression nullValueReplacement =
4049 make.Conditional(makeBinary(NE,
4050 unbox(make.Ident(dollar_s), syms.intType),
4051 makeLit(syms.intType, nullValue)),
4052 unbox(make.Ident(dollar_s), syms.intType),
4053 makeLit(syms.intType, replacementValue))
4054 .setType(syms.intType);
4055 JCExpression nullCheck =
4056 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()),
4057 nullValueReplacement,
4058 makeLit(syms.intType, nullValue))
4059 .setType(syms.intType);
4060 newSelector = make.LetExpr(List.of(var), nullCheck).setType(syms.intType);
4061 } else {
4062 newSelector = unbox(selector, syms.intType);
4063 }
4064
4065 if (tree.hasTag(SWITCH)) {
4066 ((JCSwitch) tree).selector = newSelector;
4067 } else {
4068 ((JCSwitchExpression) tree).selector = newSelector;
4069 }
4070
4071 return tree;
4072 }
4073
4074 @Override
4075 public void visitBreak(JCBreak tree) {
4076 result = tree;
4077 }
4078
4079 @Override
4080 public void visitYield(JCYield tree) {
4081 tree.value = translate(tree.value, tree.target.type);
4082 result = tree;
4083 }
4084
4085 public void visitNewArray(JCNewArray tree) {
4086 tree.elemtype = translate(tree.elemtype);
4087 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail)
4088 if (t.head != null) t.head = translate(t.head, syms.intType);
4089 tree.elems = translate(tree.elems, types.elemtype(tree.type));
4090 result = tree;
4091 }
4092
4093 public void visitSelect(JCFieldAccess tree) {
4094 // need to special case-access of the form C.super.x
4095 // these will always need an access method, unless C
4096 // is a default interface subclassed by the current class.
4097 boolean qualifiedSuperAccess =
4098 tree.selected.hasTag(SELECT) &&
4099 TreeInfo.name(tree.selected) == names._super &&
4100 !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass);
4101 /* JDK-8269956: Where a reflective (class) literal is needed, the unqualified Point.class is
4102 * always the "primary" mirror - representing the primitive reference runtime type - thereby
4103 * always matching the behavior of Object::getClass
4104 */
4105 boolean needPrimaryMirror = tree.name == names._class && tree.selected.type.isReferenceProjection();
4106 tree.selected = translate(tree.selected);
4107 if (needPrimaryMirror && tree.selected.type.isPrimitiveClass()) {
4108 tree.selected.setType(tree.selected.type.referenceProjection());
4109 }
4110 if (tree.name == names._class) {
4111 result = classOf(tree.selected);
4112 }
4113 else if (tree.name == names._super &&
4114 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) {
4115 //default super call!! Not a classic qualified super call
4116 TypeSymbol supSym = tree.selected.type.tsym;
4117 Assert.checkNonNull(types.asSuper(currentClass.type.referenceProjectionOrSelf(), supSym));
4118 result = tree;
4119 }
4120 else if (tree.name == names._this || tree.name == names._super) {
4121 result = makeThis(tree.pos(), tree.selected.type.tsym);
4122 }
4123 else
4124 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess);
4125 }
4126
4127 public void visitLetExpr(LetExpr tree) {
4128 tree.defs = translate(tree.defs);
4129 tree.expr = translate(tree.expr, tree.type);
4130 result = tree;
4131 }
4132
4133 // There ought to be nothing to rewrite here;
4134 // we don't generate code.
4135 public void visitAnnotation(JCAnnotation tree) {
4136 result = tree;
4137 }
4138
4139 @Override
4140 public void visitTry(JCTry tree) {
4141 if (tree.resources.nonEmpty()) {
4142 result = makeTwrTry(tree);
4143 return;
4144 }
4145
4146 boolean hasBody = tree.body.getStatements().nonEmpty();
4147 boolean hasCatchers = tree.catchers.nonEmpty();
4148 boolean hasFinally = tree.finalizer != null &&
4149 tree.finalizer.getStatements().nonEmpty();
4150
4151 if (!hasCatchers && !hasFinally) {
4152 result = translate(tree.body);
4153 return;
4154 }
4155
4156 if (!hasBody) {
4157 if (hasFinally) {
4158 result = translate(tree.finalizer);
4159 } else {
4160 result = translate(tree.body);
4161 }
4162 return;
4163 }
4164
4165 // no optimizations possible
4166 super.visitTry(tree);
4167 }
4168
4169 /**************************************************************************
4170 * main method
4171 *************************************************************************/
4172
4173 /** Translate a toplevel class and return a list consisting of
4174 * the translated class and translated versions of all inner classes.
4175 * @param env The attribution environment current at the class definition.
4176 * We need this for resolving some additional symbols.
4177 * @param cdef The tree representing the class definition.
4178 */
4179 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) {
4180 ListBuffer<JCTree> translated = null;
4181 try {
4182 attrEnv = env;
4183 this.make = make;
4184 endPosTable = env.toplevel.endPositions;
4185 currentClass = null;
4186 currentMethodDef = null;
4187 outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null;
4188 outermostMemberDef = null;
4189 this.translated = new ListBuffer<>();
4190 classdefs = new HashMap<>();
4191 actualSymbols = new HashMap<>();
4192 freevarCache = new HashMap<>();
4193 proxies = new HashMap<>();
4194 twrVars = WriteableScope.create(syms.noSymbol);
4195 outerThisStack = List.nil();
4196 accessNums = new HashMap<>();
4197 accessSyms = new HashMap<>();
4198 accessConstrs = new HashMap<>();
4199 accessConstrTags = List.nil();
4200 accessed = new ListBuffer<>();
4201 translate(cdef, (JCExpression)null);
4202 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail)
4203 makeAccessible(l.head);
4204 for (EnumMapping map : enumSwitchMap.values())
4205 map.translate();
4206 checkConflicts(this.translated.toList());
4207 checkAccessConstructorTags();
4208 translated = this.translated;
4209 } finally {
4210 // note that recursive invocations of this method fail hard
4211 attrEnv = null;
4212 this.make = null;
4213 endPosTable = null;
4214 currentClass = null;
4215 currentMethodDef = null;
4216 outermostClassDef = null;
4217 outermostMemberDef = null;
4218 this.translated = null;
4219 classdefs = null;
4220 actualSymbols = null;
4221 freevarCache = null;
4222 proxies = null;
4223 outerThisStack = null;
4224 accessNums = null;
4225 accessSyms = null;
4226 accessConstrs = null;
4227 accessConstrTags = null;
4228 accessed = null;
4229 enumSwitchMap.clear();
4230 assertionsDisabledClassCache = null;
4231 }
4232 return translated.toList();
4233 }
4234 }