1 /*
2 * Copyright (c) 1999, 2025, 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.source.tree.LambdaExpressionTree.BodyKind;
32 import com.sun.tools.javac.code.*;
33 import com.sun.tools.javac.code.Kinds.KindSelector;
34 import com.sun.tools.javac.code.Scope.WriteableScope;
35 import com.sun.tools.javac.jvm.*;
36 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
37 import com.sun.tools.javac.main.Option.PkgInfo;
38 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
39 import com.sun.tools.javac.tree.*;
40 import com.sun.tools.javac.util.*;
41 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
42 import com.sun.tools.javac.util.List;
43
44 import com.sun.tools.javac.code.Symbol.*;
45 import com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode;
46 import com.sun.tools.javac.resources.CompilerProperties.Errors;
47 import com.sun.tools.javac.tree.JCTree.*;
48 import com.sun.tools.javac.code.Type.*;
49
50 import com.sun.tools.javac.jvm.Target;
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 com.sun.tools.javac.code.Source.Feature;
58 import static com.sun.tools.javac.jvm.ByteCodes.*;
59 import com.sun.tools.javac.tree.JCTree.JCBreak;
60 import com.sun.tools.javac.tree.JCTree.JCCase;
61 import com.sun.tools.javac.tree.JCTree.JCExpression;
62 import com.sun.tools.javac.tree.JCTree.JCExpressionStatement;
63
64 import static com.sun.tools.javac.tree.JCTree.JCOperatorExpression.OperandPos.LEFT;
65 import com.sun.tools.javac.tree.JCTree.JCSwitchExpression;
66
67 import static com.sun.tools.javac.tree.JCTree.Tag.*;
68
69 /** This pass translates away some syntactic sugar: inner classes,
70 * class literals, assertions, foreach loops, etc.
71 *
72 * <p><b>This is NOT part of any supported API.
73 * If you write code that depends on this, you do so at your own risk.
74 * This code and its internal interfaces are subject to change or
75 * deletion without notice.</b>
76 */
77 public class Lower extends TreeTranslator {
78 protected static final Context.Key<Lower> lowerKey = new Context.Key<>();
79
80 public static Lower instance(Context context) {
81 Lower instance = context.get(lowerKey);
82 if (instance == null)
83 instance = new Lower(context);
84 return instance;
85 }
86
87 private final Names names;
88 private final Log log;
89 private final Symtab syms;
90 private final Resolve rs;
91 private final Operators operators;
92 private final Check chk;
93 private final Attr attr;
94 private TreeMaker make;
95 private DiagnosticPosition make_pos;
96 private final ConstFold cfolder;
97 private final Target target;
98 private final TypeEnvs typeEnvs;
99 private final Name dollarAssertionsDisabled;
100 private final Types types;
101 private final TransTypes transTypes;
102 private final boolean debugLower;
103 private final boolean disableProtectedAccessors; // experimental
104 private final PkgInfo pkginfoOpt;
105 private final boolean optimizeOuterThis;
106 private final boolean nullCheckOuterThis;
107 private final boolean useMatchException;
108 private final HashMap<TypePairs, String> typePairToName;
109 private int variableIndex = 0;
110
111 @SuppressWarnings("this-escape")
112 protected Lower(Context context) {
113 context.put(lowerKey, this);
114 names = Names.instance(context);
115 log = Log.instance(context);
116 syms = Symtab.instance(context);
117 rs = Resolve.instance(context);
118 operators = Operators.instance(context);
119 chk = Check.instance(context);
120 attr = Attr.instance(context);
121 make = TreeMaker.instance(context);
122 cfolder = ConstFold.instance(context);
123 target = Target.instance(context);
124 typeEnvs = TypeEnvs.instance(context);
125 dollarAssertionsDisabled = names.
126 fromString(target.syntheticNameChar() + "assertionsDisabled");
127
128 types = Types.instance(context);
129 transTypes = TransTypes.instance(context);
130 Options options = Options.instance(context);
131 debugLower = options.isSet("debuglower");
132 pkginfoOpt = PkgInfo.get(options);
133 optimizeOuterThis =
134 target.optimizeOuterThis() ||
135 options.getBoolean("optimizeOuterThis", false);
136 nullCheckOuterThis = options.getBoolean("nullCheckOuterThis",
137 target.nullCheckOuterThisByDefault());
138 disableProtectedAccessors = options.isSet("disableProtectedAccessors");
139 Source source = Source.instance(context);
140 Preview preview = Preview.instance(context);
141 useMatchException = Feature.PATTERN_SWITCH.allowedInSource(source) &&
142 (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH));
143 typePairToName = TypePairs.initialize(syms);
144 }
145
146 /** The currently enclosing class.
147 */
148 ClassSymbol currentClass;
149
150 /** A queue of all translated classes.
151 */
152 ListBuffer<JCTree> translated;
153
154 /** Environment for symbol lookup, set by translateTopLevelClass.
155 */
156 Env<AttrContext> attrEnv;
157
158 /* ************************************************************************
159 * Global mappings
160 *************************************************************************/
161
162 /** A hash table mapping local classes to their definitions.
163 */
164 Map<ClassSymbol, JCClassDecl> classdefs;
165
166 /** A hash table mapping local classes to a list of pruned trees.
167 */
168 public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<>();
169
170 /** A hash table mapping virtual accessed symbols in outer subclasses
171 * to the actually referred symbol in superclasses.
172 */
173 Map<Symbol,Symbol> actualSymbols;
174
175 /**
176 * The current expected return type.
177 */
178 Type currentRestype;
179
180 /** The current method definition.
181 */
182 JCMethodDecl currentMethodDef;
183
184 /** The current method symbol.
185 */
186 MethodSymbol currentMethodSym;
187
188 /** The currently enclosing outermost class definition.
189 */
190 JCClassDecl outermostClassDef;
191
192 /** The currently enclosing outermost member definition.
193 */
194 JCTree outermostMemberDef;
195
196 /** A navigator class for assembling a mapping from local class symbols
197 * to class definition trees.
198 * There is only one case; all other cases simply traverse down the tree.
199 */
200 class ClassMap extends TreeScanner {
201
202 /** All encountered class defs are entered into classdefs table.
203 */
204 public void visitClassDef(JCClassDecl tree) {
205 classdefs.put(tree.sym, tree);
206 super.visitClassDef(tree);
207 }
208 }
209 ClassMap classMap = new ClassMap();
210
211 /** Map a class symbol to its definition.
212 * @param c The class symbol of which we want to determine the definition.
213 */
214 JCClassDecl classDef(ClassSymbol c) {
215 // First lookup the class in the classdefs table.
216 JCClassDecl def = classdefs.get(c);
217 if (def == null && outermostMemberDef != null) {
218 // If this fails, traverse outermost member definition, entering all
219 // local classes into classdefs, and try again.
220 classMap.scan(outermostMemberDef);
221 def = classdefs.get(c);
222 }
223 if (def == null) {
224 // If this fails, traverse outermost class definition, entering all
225 // local classes into classdefs, and try again.
226 classMap.scan(outermostClassDef);
227 def = classdefs.get(c);
228 }
229 return def;
230 }
231
232 /**
233 * Get the enum constants for the given enum class symbol, if known.
234 * They will only be found if they are defined within the same top-level
235 * class as the class being compiled, so it's safe to assume that they
236 * can't change at runtime due to a recompilation.
237 */
238 List<Name> enumNamesFor(ClassSymbol c) {
239
240 // Find the class definition and verify it is an enum class
241 final JCClassDecl classDef = classDef(c);
242 if (classDef == null ||
243 (classDef.mods.flags & ENUM) == 0 ||
244 (types.supertype(currentClass.type).tsym.flags() & ENUM) != 0) {
245 return null;
246 }
247
248 // Gather the enum identifiers
249 ListBuffer<Name> idents = new ListBuffer<>();
250 for (List<JCTree> defs = classDef.defs; defs.nonEmpty(); defs=defs.tail) {
251 if (defs.head.hasTag(VARDEF) &&
252 (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
253 JCVariableDecl var = (JCVariableDecl)defs.head;
254 idents.append(var.name);
255 }
256 }
257 return idents.toList();
258 }
259
260 /** A hash table mapping class symbols to lists of free variables.
261 * accessed by them. Only free variables of the method immediately containing
262 * a class are associated with that class.
263 */
264 Map<ClassSymbol,List<VarSymbol>> freevarCache;
265
266 /** A navigator class for collecting the free variables accessed
267 * from a local class.
268 */
269 class FreeVarCollector extends CaptureScanner {
270
271 FreeVarCollector(JCTree ownerTree) {
272 super(ownerTree);
273 }
274
275 void addFreeVars(ClassSymbol c) {
276 List<VarSymbol> fvs = freevarCache.get(c);
277 if (fvs != null) {
278 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
279 addFreeVar(l.head);
280 }
281 }
282 }
283
284 /** If tree refers to a class instance creation expression
285 * add all free variables of the freshly created class.
286 */
287 public void visitNewClass(JCNewClass tree) {
288 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
289 addFreeVars(c);
290 super.visitNewClass(tree);
291 }
292
293 /** If tree refers to a superclass constructor call,
294 * add all free variables of the superclass.
295 */
296 public void visitApply(JCMethodInvocation tree) {
297 if (TreeInfo.name(tree.meth) == names._super) {
298 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner);
299 }
300 super.visitApply(tree);
301 }
302 }
303
304 /** Return the variables accessed from within a local class, which
305 * are declared in the local class' owner.
306 * (in reverse order of first access).
307 */
308 List<VarSymbol> freevars(ClassSymbol c) {
309 List<VarSymbol> fvs = freevarCache.get(c);
310 if (fvs != null) {
311 return fvs;
312 }
313 FreeVarCollector collector = new FreeVarCollector(classDef(c));
314 fvs = collector.analyzeCaptures().reverse();
315 freevarCache.put(c, fvs);
316 return fvs;
317 }
318
319 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>();
320
321 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) {
322
323 // If enum class is part of this compilation, just switch on ordinal value
324 if (enumClass.kind == TYP) {
325 final List<Name> idents = enumNamesFor((ClassSymbol)enumClass);
326 if (idents != null)
327 return new CompileTimeEnumMapping(idents);
328 }
329
330 // Map identifiers to ordinal values at runtime, and then switch on that
331 return enumSwitchMap.computeIfAbsent(enumClass, ec -> new RuntimeEnumMapping(pos, ec));
332 }
333
334 /** Generates a test value and corresponding cases for a switch on an enum type.
335 */
336 interface EnumMapping {
337
338 /** Given an expression for the enum value's ordinal, generate an expression for the switch statement.
339 */
340 JCExpression switchValue(JCExpression ordinalExpr);
341
342 /** Generate the switch statement case value corresponding to the given enum value.
343 */
344 JCLiteral caseValue(VarSymbol v);
345
346 default void translate() {
347 }
348 }
349
350 /** EnumMapping using compile-time constants. Only valid when compiling the enum class itself,
351 * because otherwise the ordinals we use could become obsolete if/when the enum class is recompiled.
352 */
353 class CompileTimeEnumMapping implements EnumMapping {
354
355 final List<Name> enumNames;
356
357 CompileTimeEnumMapping(List<Name> enumNames) {
358 Assert.check(enumNames != null);
359 this.enumNames = enumNames;
360 }
361
362 @Override
363 public JCExpression switchValue(JCExpression ordinalExpr) {
364 return ordinalExpr;
365 }
366
367 @Override
368 public JCLiteral caseValue(VarSymbol v) {
369 final int ordinal = enumNames.indexOf(v.name);
370 Assert.check(ordinal != -1);
371 return make.Literal(ordinal);
372 }
373 }
374
375 /** EnumMapping using run-time ordinal lookup.
376 *
377 * This builds a translation table to be used for enum switches.
378 *
379 * <p>For each enum that appears as the type of a switch
380 * expression, we maintain an EnumMapping to assist in the
381 * translation, as exemplified by the following example:
382 *
383 * <p>we translate
384 * <pre>
385 * switch(colorExpression) {
386 * case red: stmt1;
387 * case green: stmt2;
388 * }
389 * </pre>
390 * into
391 * <pre>
392 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) {
393 * case 1: stmt1;
394 * case 2: stmt2
395 * }
396 * </pre>
397 * with the auxiliary table initialized as follows:
398 * <pre>
399 * class Outer$0 {
400 * synthetic final int[] $EnumMap$Color = new int[Color.values().length];
401 * static {
402 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {}
403 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {}
404 * }
405 * }
406 * </pre>
407 * class EnumMapping provides mapping data and support methods for this translation.
408 */
409 class RuntimeEnumMapping implements EnumMapping {
410 RuntimeEnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) {
411 this.forEnum = forEnum;
412 this.values = new LinkedHashMap<>();
413 this.pos = pos;
414 Name varName = names
415 .fromString(target.syntheticNameChar() +
416 "SwitchMap" +
417 target.syntheticNameChar() +
418 ClassWriter.externalize(forEnum.type.tsym.flatName().toString())
419 .replace('/', '.')
420 .replace('.', target.syntheticNameChar()));
421 ClassSymbol outerCacheClass = outerCacheClass();
422 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL,
423 varName,
424 new ArrayType(syms.intType, syms.arrayClass),
425 outerCacheClass);
426 enterSynthetic(pos, mapVar, outerCacheClass.members());
427 }
428
429 DiagnosticPosition pos = null;
430
431 // the next value to use
432 int next = 1; // 0 (unused map elements) go to the default label
433
434 // the enum for which this is a map
435 final TypeSymbol forEnum;
436
437 // the field containing the map
438 final VarSymbol mapVar;
439
440 // the mapped values
441 final Map<VarSymbol,Integer> values;
442
443 @Override
444 public JCExpression switchValue(JCExpression ordinalExpr) {
445 return make.Indexed(mapVar, ordinalExpr);
446 }
447
448 @Override
449 public JCLiteral caseValue(VarSymbol v) {
450 Integer result = values.get(v);
451 if (result == null)
452 values.put(v, result = next++);
453 return make.Literal(result);
454 }
455
456 // generate the field initializer for the map
457 @Override
458 public void translate() {
459 boolean prevAllowProtectedAccess = attrEnv.info.allowProtectedAccess;
460 try {
461 make.at(pos.getStartPosition());
462 attrEnv.info.allowProtectedAccess = true;
463 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner);
464
465 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length];
466 MethodSymbol valuesMethod = lookupMethod(pos,
467 names.values,
468 forEnum.type,
469 List.nil());
470 JCExpression size = make // Color.values().length
471 .Select(make.App(make.QualIdent(valuesMethod)),
472 syms.lengthVar);
473 JCExpression mapVarInit = make
474 .NewArray(make.Type(syms.intType), List.of(size), null)
475 .setType(new ArrayType(syms.intType, syms.arrayClass));
476
477 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {}
478 ListBuffer<JCStatement> stmts = new ListBuffer<>();
479 Symbol ordinalMethod = lookupMethod(pos,
480 names.ordinal,
481 forEnum.type,
482 List.nil());
483 List<JCCatch> catcher = List.<JCCatch>nil()
484 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex,
485 syms.noSuchFieldErrorType,
486 syms.noSymbol),
487 null),
488 make.Block(0, List.nil())));
489 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) {
490 VarSymbol enumerator = e.getKey();
491 Integer mappedValue = e.getValue();
492 JCExpression assign = make
493 .Assign(make.Indexed(mapVar,
494 make.App(make.Select(make.QualIdent(enumerator),
495 ordinalMethod))),
496 make.Literal(mappedValue))
497 .setType(syms.intType);
498 JCStatement exec = make.Exec(assign);
499 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null);
500 stmts.append(_try);
501 }
502
503 owner.defs = owner.defs
504 .prepend(make.Block(STATIC, stmts.toList()))
505 .prepend(make.VarDef(mapVar, mapVarInit));
506 } finally {
507 attrEnv.info.allowProtectedAccess = prevAllowProtectedAccess;
508 }
509 }
510 }
511
512
513 /* ************************************************************************
514 * Tree building blocks
515 *************************************************************************/
516
517 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching
518 * pos as make_pos, for use in diagnostics.
519 **/
520 TreeMaker make_at(DiagnosticPosition pos) {
521 make_pos = pos;
522 return make.at(pos);
523 }
524
525 /** Make an attributed tree representing a literal. This will be an
526 * Ident node in the case of boolean literals, a Literal node in all
527 * other cases.
528 * @param type The literal's type.
529 * @param value The literal's value.
530 */
531 JCExpression makeLit(Type type, Object value) {
532 return make.Literal(type.getTag(), value).setType(type.constType(value));
533 }
534
535 /** Make an attributed tree representing null.
536 */
537 JCExpression makeNull() {
538 return makeLit(syms.botType, null);
539 }
540
541 /** Make an attributed class instance creation expression.
542 * @param ctype The class type.
543 * @param args The constructor arguments.
544 */
545 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
546 JCNewClass tree = make.NewClass(null,
547 null, make.QualIdent(ctype.tsym), args, null);
548 tree.constructor = rs.resolveConstructor(
549 make_pos, attrEnv, ctype, TreeInfo.types(args), List.nil());
550 tree.type = ctype;
551 return tree;
552 }
553
554 /** Make an attributed unary expression.
555 * @param optag The operators tree tag.
556 * @param arg The operator's argument.
557 */
558 JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) {
559 JCUnary tree = make.Unary(optag, arg);
560 tree.operator = operators.resolveUnary(tree, optag, arg.type);
561 tree.type = tree.operator.type.getReturnType();
562 return tree;
563 }
564
565 /** Make an attributed binary expression.
566 * @param optag The operators tree tag.
567 * @param lhs The operator's left argument.
568 * @param rhs The operator's right argument.
569 */
570 JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) {
571 JCBinary tree = make.Binary(optag, lhs, rhs);
572 tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type);
573 tree.type = tree.operator.type.getReturnType();
574 return tree;
575 }
576
577 /** Make an attributed assignop expression.
578 * @param optag The operators tree tag.
579 * @param lhs The operator's left argument.
580 * @param rhs The operator's right argument.
581 */
582 JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) {
583 JCAssignOp tree = make.Assignop(optag, lhs, rhs);
584 tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type);
585 tree.type = lhs.type;
586 return tree;
587 }
588
589 /** Convert tree into string object, unless it has already a
590 * reference type..
591 */
592 JCExpression makeString(JCExpression tree) {
593 if (!tree.type.isPrimitiveOrVoid()) {
594 return tree;
595 } else {
596 Symbol valueOfSym = lookupMethod(tree.pos(),
597 names.valueOf,
598 syms.stringType,
599 List.of(tree.type));
600 return make.App(make.QualIdent(valueOfSym), List.of(tree));
601 }
602 }
603
604 /** Create an empty anonymous class definition and enter and complete
605 * its symbol. Return the class definition's symbol.
606 * and create
607 * @param flags The class symbol's flags
608 * @param owner The class symbol's owner
609 */
610 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) {
611 return makeEmptyClass(flags, owner, null, true);
612 }
613
614 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname,
615 boolean addToDefs) {
616 // Create class symbol.
617 ClassSymbol c = syms.defineClass(names.empty, owner);
618 if (flatname != null) {
619 c.flatname = flatname;
620 } else {
621 c.flatname = chk.localClassName(c);
622 }
623 c.sourcefile = owner.sourcefile;
624 c.completer = Completer.NULL_COMPLETER;
625 c.members_field = WriteableScope.create(c);
626 c.flags_field = flags;
627 ClassType ctype = (ClassType) c.type;
628 ctype.supertype_field = syms.objectType;
629 ctype.interfaces_field = List.nil();
630
631 JCClassDecl odef = classDef(owner);
632
633 // Enter class symbol in owner scope and compiled table.
634 enterSynthetic(odef.pos(), c, owner.members());
635 chk.putCompiled(c);
636
637 // Create class definition tree.
638 JCClassDecl cdef = make.ClassDef(
639 make.Modifiers(flags), names.empty,
640 List.nil(),
641 null, List.nil(), List.nil());
642 cdef.sym = c;
643 cdef.type = c.type;
644
645 // Append class definition tree to owner's definitions.
646 if (addToDefs) odef.defs = odef.defs.prepend(cdef);
647 return cdef;
648 }
649
650 /* ************************************************************************
651 * Symbol manipulation utilities
652 *************************************************************************/
653
654 /** Enter a synthetic symbol in a given scope, but complain if there was already one there.
655 * @param pos Position for error reporting.
656 * @param sym The symbol.
657 * @param s The scope.
658 */
659 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) {
660 s.enter(sym);
661 }
662
663 /** Create a fresh synthetic name within a given scope - the unique name is
664 * obtained by appending '$' chars at the end of the name until no match
665 * is found.
666 *
667 * @param name base name
668 * @param s scope in which the name has to be unique
669 * @return fresh synthetic name
670 */
671 private Name makeSyntheticName(Name name, Scope s) {
672 do {
673 name = name.append(
674 target.syntheticNameChar(),
675 names.empty);
676 } while (lookupSynthetic(name, s) != null);
677 return name;
678 }
679
680 /** Check whether synthetic symbols generated during lowering conflict
681 * with user-defined symbols.
682 *
683 * @param translatedTrees lowered class trees
684 */
685 void checkConflicts(List<JCTree> translatedTrees) {
686 for (JCTree t : translatedTrees) {
687 t.accept(conflictsChecker);
688 }
689 }
690
691 JCTree.Visitor conflictsChecker = new TreeScanner() {
692
693 TypeSymbol currentClass;
694
695 @Override
696 public void visitMethodDef(JCMethodDecl that) {
697 checkConflicts(that.pos(), that.sym, currentClass);
698 super.visitMethodDef(that);
699 }
700
701 @Override
702 public void visitVarDef(JCVariableDecl that) {
703 if (that.sym.owner.kind == TYP) {
704 checkConflicts(that.pos(), that.sym, currentClass);
705 }
706 super.visitVarDef(that);
707 }
708
709 @Override
710 public void visitClassDef(JCClassDecl that) {
711 TypeSymbol prevCurrentClass = currentClass;
712 currentClass = that.sym;
713 try {
714 super.visitClassDef(that);
715 }
716 finally {
717 currentClass = prevCurrentClass;
718 }
719 }
720
721 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
722 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
723 for (Symbol sym2 : ct.tsym.members().getSymbolsByName(sym.name, NON_RECURSIVE)) {
724 // VM allows methods and variables with differing types
725 if (sym.kind == sym2.kind &&
726 types.isSameType(types.erasure(sym.type), types.erasure(sym2.type)) &&
727 sym != sym2 &&
728 (sym.flags() & Flags.SYNTHETIC) != (sym2.flags() & Flags.SYNTHETIC) &&
729 (sym.flags() & BRIDGE) == 0 && (sym2.flags() & BRIDGE) == 0) {
730 syntheticError(pos, (sym2.flags() & SYNTHETIC) == 0 ? sym2 : sym);
731 return;
732 }
733 }
734 }
735 }
736
737 /** Report a conflict between a user symbol and a synthetic symbol.
738 */
739 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
740 if (!sym.type.isErroneous()) {
741 log.error(pos, Errors.CannotGenerateClass(sym.location(), Fragments.SyntheticNameConflict(sym, sym.location())));
742 }
743 }
744 };
745
746 /** Look up a synthetic name in a given scope.
747 * @param s The scope.
748 * @param name The name.
749 */
750 private Symbol lookupSynthetic(Name name, Scope s) {
751 Symbol sym = s.findFirst(name);
752 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym;
753 }
754
755 /** Look up a method in a given scope.
756 */
757 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) {
758 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.nil());
759 }
760
761 /** Anon inner classes are used as access constructor tags.
762 * accessConstructorTag will use an existing anon class if one is available,
763 * and synthesize a class (with makeEmptyClass) if one is not available.
764 * However, there is a small possibility that an existing class will not
765 * be generated as expected if it is inside a conditional with a constant
766 * expression. If that is found to be the case, create an empty class tree here.
767 */
768 private void checkAccessConstructorTags() {
769 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) {
770 ClassSymbol c = l.head;
771 if (isTranslatedClassAvailable(c))
772 continue;
773 // Create class definition tree.
774 JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC,
775 c.outermostClass(), c.flatname, false);
776 swapAccessConstructorTag(c, cdec.sym);
777 translated.append(cdec);
778 }
779 }
780 // where
781 private boolean isTranslatedClassAvailable(ClassSymbol c) {
782 for (JCTree tree: translated) {
783 if (tree.hasTag(CLASSDEF)
784 && ((JCClassDecl) tree).sym == c) {
785 return true;
786 }
787 }
788 return false;
789 }
790
791 void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) {
792 for (MethodSymbol methodSymbol : accessConstrs.values()) {
793 Assert.check(methodSymbol.type.hasTag(METHOD));
794 MethodType oldMethodType =
795 (MethodType)methodSymbol.type;
796 if (oldMethodType.argtypes.head.tsym == oldCTag)
797 methodSymbol.type =
798 types.createMethodTypeWithParameters(oldMethodType,
799 oldMethodType.getParameterTypes().tail
800 .prepend(newCTag.erasure(types)));
801 }
802 }
803
804 /* ************************************************************************
805 * Access methods
806 *************************************************************************/
807
808 /** A mapping from symbols to their access numbers.
809 */
810 private Map<Symbol,Integer> accessNums;
811
812 /** A mapping from symbols to an array of access symbols, indexed by
813 * access code.
814 */
815 private Map<Symbol,MethodSymbol[]> accessSyms;
816
817 /** A mapping from (constructor) symbols to access constructor symbols.
818 */
819 private Map<Symbol,MethodSymbol> accessConstrs;
820
821 /** A list of all class symbols used for access constructor tags.
822 */
823 private List<ClassSymbol> accessConstrTags;
824
825 /** A queue for all accessed symbols.
826 */
827 private ListBuffer<Symbol> accessed;
828
829 /** return access code for identifier,
830 * @param tree The tree representing the identifier use.
831 * @param enclOp The closest enclosing operation node of tree,
832 * null if tree is not a subtree of an operation.
833 */
834 private static int accessCode(JCTree tree, JCTree enclOp) {
835 if (enclOp == null)
836 return AccessCode.DEREF.code;
837 else if (enclOp.hasTag(ASSIGN) &&
838 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs))
839 return AccessCode.ASSIGN.code;
840 else if ((enclOp.getTag().isIncOrDecUnaryOp() || enclOp.getTag().isAssignop()) &&
841 tree == TreeInfo.skipParens(((JCOperatorExpression) enclOp).getOperand(LEFT)))
842 return (((JCOperatorExpression) enclOp).operator).getAccessCode(enclOp.getTag());
843 else
844 return AccessCode.DEREF.code;
845 }
846
847 /** Return binary operator that corresponds to given access code.
848 */
849 private OperatorSymbol binaryAccessOperator(int acode, Tag tag) {
850 return operators.lookupBinaryOp(op -> op.getAccessCode(tag) == acode);
851 }
852
853 /** Return tree tag for assignment operation corresponding
854 * to given binary operator.
855 */
856 private static JCTree.Tag treeTag(OperatorSymbol operator) {
857 switch (operator.opcode) {
858 case ByteCodes.ior: case ByteCodes.lor:
859 return BITOR_ASG;
860 case ByteCodes.ixor: case ByteCodes.lxor:
861 return BITXOR_ASG;
862 case ByteCodes.iand: case ByteCodes.land:
863 return BITAND_ASG;
864 case ByteCodes.ishl: case ByteCodes.lshl:
865 case ByteCodes.ishll: case ByteCodes.lshll:
866 return SL_ASG;
867 case ByteCodes.ishr: case ByteCodes.lshr:
868 case ByteCodes.ishrl: case ByteCodes.lshrl:
869 return SR_ASG;
870 case ByteCodes.iushr: case ByteCodes.lushr:
871 case ByteCodes.iushrl: case ByteCodes.lushrl:
872 return USR_ASG;
873 case ByteCodes.iadd: case ByteCodes.ladd:
874 case ByteCodes.fadd: case ByteCodes.dadd:
875 case ByteCodes.string_add:
876 return PLUS_ASG;
877 case ByteCodes.isub: case ByteCodes.lsub:
878 case ByteCodes.fsub: case ByteCodes.dsub:
879 return MINUS_ASG;
880 case ByteCodes.imul: case ByteCodes.lmul:
881 case ByteCodes.fmul: case ByteCodes.dmul:
882 return MUL_ASG;
883 case ByteCodes.idiv: case ByteCodes.ldiv:
884 case ByteCodes.fdiv: case ByteCodes.ddiv:
885 return DIV_ASG;
886 case ByteCodes.imod: case ByteCodes.lmod:
887 case ByteCodes.fmod: case ByteCodes.dmod:
888 return MOD_ASG;
889 default:
890 throw new AssertionError();
891 }
892 }
893
894 /** The name of the access method with number `anum' and access code `acode'.
895 */
896 Name accessName(int anum, int acode) {
897 return names.fromString(
898 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10);
899 }
900
901 /** Return access symbol for a private or protected symbol from an inner class.
902 * @param sym The accessed private symbol.
903 * @param tree The accessing tree.
904 * @param enclOp The closest enclosing operation node of tree,
905 * null if tree is not a subtree of an operation.
906 * @param protAccess Is access to a protected symbol in another
907 * package?
908 * @param refSuper Is access via a (qualified) C.super?
909 */
910 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp,
911 boolean protAccess, boolean refSuper) {
912 ClassSymbol accOwner = refSuper && protAccess
913 // For access via qualified super (T.super.x), place the
914 // access symbol on T.
915 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym
916 // Otherwise pretend that the owner of an accessed
917 // protected symbol is the enclosing class of the current
918 // class which is a subclass of the symbol's owner.
919 : accessClass(sym, protAccess, tree);
920
921 Symbol vsym = sym;
922 if (sym.owner != accOwner) {
923 vsym = sym.clone(accOwner);
924 actualSymbols.put(vsym, sym);
925 }
926
927 Integer anum // The access number of the access method.
928 = accessNums.get(vsym);
929 if (anum == null) {
930 anum = accessed.length();
931 accessNums.put(vsym, anum);
932 accessSyms.put(vsym, new MethodSymbol[AccessCode.numberOfAccessCodes]);
933 accessed.append(vsym);
934 // System.out.println("accessing " + vsym + " in " + vsym.location());
935 }
936
937 int acode; // The access code of the access method.
938 List<Type> argtypes; // The argument types of the access method.
939 Type restype; // The result type of the access method.
940 List<Type> thrown; // The thrown exceptions of the access method.
941 switch (vsym.kind) {
942 case VAR:
943 acode = accessCode(tree, enclOp);
944 if (acode >= AccessCode.FIRSTASGOP.code) {
945 OperatorSymbol operator = binaryAccessOperator(acode, enclOp.getTag());
946 if (operator.opcode == string_add)
947 argtypes = List.of(syms.objectType);
948 else
949 argtypes = operator.type.getParameterTypes().tail;
950 } else if (acode == AccessCode.ASSIGN.code)
951 argtypes = List.of(vsym.erasure(types));
952 else
953 argtypes = List.nil();
954 restype = vsym.erasure(types);
955 thrown = List.nil();
956 break;
957 case MTH:
958 acode = AccessCode.DEREF.code;
959 argtypes = vsym.erasure(types).getParameterTypes();
960 restype = vsym.erasure(types).getReturnType();
961 thrown = vsym.type.getThrownTypes();
962 break;
963 default:
964 throw new AssertionError();
965 }
966
967 // For references via qualified super, increment acode by one,
968 // making it odd.
969 if (protAccess && refSuper) acode++;
970
971 // Instance access methods get instance as first parameter.
972 // For protected symbols this needs to be the instance as a member
973 // of the type containing the accessed symbol, not the class
974 // containing the access method.
975 if ((vsym.flags() & STATIC) == 0) {
976 argtypes = argtypes.prepend(vsym.owner.erasure(types));
977 }
978 MethodSymbol[] accessors = accessSyms.get(vsym);
979 MethodSymbol accessor = accessors[acode];
980 if (accessor == null) {
981 accessor = new MethodSymbol(
982 STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0),
983 accessName(anum.intValue(), acode),
984 new MethodType(argtypes, restype, thrown, syms.methodClass),
985 accOwner);
986 enterSynthetic(tree.pos(), accessor, accOwner.members());
987 accessors[acode] = accessor;
988 }
989 return accessor;
990 }
991
992 /** The qualifier to be used for accessing a symbol in an outer class.
993 * This is either C.sym or C.this.sym, depending on whether or not
994 * sym is static.
995 * @param sym The accessed symbol.
996 */
997 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) {
998 return (sym.flags() & STATIC) != 0
999 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner))
1000 : makeOwnerThis(pos, sym, true);
1001 }
1002
1003 /** Do we need an access method to reference private symbol?
1004 */
1005 boolean needsPrivateAccess(Symbol sym) {
1006 if (target.hasNestmateAccess()) {
1007 return false;
1008 }
1009 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) {
1010 return false;
1011 } else if (sym.name == names.init && sym.owner.isDirectlyOrIndirectlyLocal()) {
1012 // private constructor in local class: relax protection
1013 sym.flags_field &= ~PRIVATE;
1014 return false;
1015 } else {
1016 return true;
1017 }
1018 }
1019
1020 /** Do we need an access method to reference symbol in other package?
1021 */
1022 boolean needsProtectedAccess(Symbol sym, JCTree tree) {
1023 if (disableProtectedAccessors) return false;
1024 if ((sym.flags() & PROTECTED) == 0 ||
1025 sym.owner.owner == currentClass.owner || // fast special case
1026 sym.packge() == currentClass.packge())
1027 return false;
1028 if (!currentClass.isSubClass(sym.owner, types))
1029 return true;
1030 if ((sym.flags() & STATIC) != 0 ||
1031 !tree.hasTag(SELECT) ||
1032 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super)
1033 return false;
1034 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types);
1035 }
1036
1037 /** The class in which an access method for given symbol goes.
1038 * @param sym The access symbol
1039 * @param protAccess Is access to a protected symbol in another
1040 * package?
1041 */
1042 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) {
1043 if (protAccess) {
1044 Symbol qualifier = null;
1045 ClassSymbol c = currentClass;
1046 if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) {
1047 qualifier = ((JCFieldAccess) tree).selected.type.tsym;
1048 while (!qualifier.isSubClass(c, types)) {
1049 c = c.owner.enclClass();
1050 }
1051 return c;
1052 } else {
1053 while (!c.isSubClass(sym.owner, types)) {
1054 c = c.owner.enclClass();
1055 }
1056 }
1057 return c;
1058 } else {
1059 // the symbol is private
1060 return sym.owner.enclClass();
1061 }
1062 }
1063
1064 private boolean noClassDefIn(JCTree tree) {
1065 var scanner = new TreeScanner() {
1066 boolean noClassDef = true;
1067 @Override
1068 public void visitClassDef(JCClassDecl tree) {
1069 noClassDef = false;
1070 }
1071 };
1072 scanner.scan(tree);
1073 return scanner.noClassDef;
1074 }
1075
1076 private void addPrunedInfo(JCTree tree) {
1077 List<JCTree> infoList = prunedTree.get(currentClass);
1078 infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree);
1079 prunedTree.put(currentClass, infoList);
1080 }
1081
1082 /** Ensure that identifier is accessible, return tree accessing the identifier.
1083 * @param sym The accessed symbol.
1084 * @param tree The tree referring to the symbol.
1085 * @param enclOp The closest enclosing operation node of tree,
1086 * null if tree is not a subtree of an operation.
1087 * @param refSuper Is access via a (qualified) C.super?
1088 */
1089 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) {
1090 // Access a free variable via its proxy, or its proxy's proxy
1091 while (sym.kind == VAR && sym.owner.kind == MTH &&
1092 sym.owner.enclClass() != currentClass) {
1093 // A constant is replaced by its constant value.
1094 Object cv = ((VarSymbol)sym).getConstValue();
1095 if (cv != null) {
1096 make.at(tree.pos);
1097 return makeLit(sym.type, cv);
1098 }
1099 // Otherwise replace the variable by its proxy.
1100 sym = proxies.get(sym);
1101 Assert.check(sym != null && (sym.flags_field & FINAL) != 0);
1102 tree = make.at(tree.pos).Ident(sym);
1103 }
1104 JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null;
1105 switch (sym.kind) {
1106 case TYP:
1107 if (sym.owner.kind != PCK) {
1108 // Convert type idents to
1109 // <flat name> or <package name> . <flat name>
1110 Name flatname = Convert.shortName(sym.flatName());
1111 while (base != null &&
1112 TreeInfo.symbol(base) != null &&
1113 TreeInfo.symbol(base).kind != PCK) {
1114 base = (base.hasTag(SELECT))
1115 ? ((JCFieldAccess) base).selected
1116 : null;
1117 }
1118 if (tree.hasTag(IDENT)) {
1119 ((JCIdent) tree).name = flatname;
1120 } else if (base == null) {
1121 tree = make.at(tree.pos).Ident(sym);
1122 ((JCIdent) tree).name = flatname;
1123 } else {
1124 ((JCFieldAccess) tree).selected = base;
1125 ((JCFieldAccess) tree).name = flatname;
1126 }
1127 }
1128 break;
1129 case MTH: case VAR:
1130 if (sym.owner.kind == TYP) {
1131
1132 // Access methods are required for
1133 // - private members,
1134 // - protected members in a superclass of an
1135 // enclosing class contained in another package.
1136 // - all non-private members accessed via a qualified super.
1137 boolean protAccess = refSuper && !needsPrivateAccess(sym)
1138 || needsProtectedAccess(sym, tree);
1139 boolean accReq = protAccess || needsPrivateAccess(sym);
1140
1141 // A base has to be supplied for
1142 // - simple identifiers accessing variables in outer classes.
1143 boolean baseReq =
1144 base == null &&
1145 sym.owner != syms.predefClass &&
1146 !sym.isMemberOf(currentClass, types);
1147
1148 if (accReq || baseReq) {
1149 make.at(tree.pos);
1150
1151 // Constants are replaced by their constant value.
1152 if (sym.kind == VAR) {
1153 Object cv = ((VarSymbol)sym).getConstValue();
1154 if (cv != null) {
1155 addPrunedInfo(tree);
1156 return makeLit(sym.type, cv);
1157 }
1158 }
1159
1160 // Private variables and methods are replaced by calls
1161 // to their access methods.
1162 if (accReq) {
1163 List<JCExpression> args = List.nil();
1164 if ((sym.flags() & STATIC) == 0) {
1165 // Instance access methods get instance
1166 // as first parameter.
1167 if (base == null)
1168 base = makeOwnerThis(tree.pos(), sym, true);
1169 args = args.prepend(base);
1170 base = null; // so we don't duplicate code
1171 }
1172 Symbol access = accessSymbol(sym, tree,
1173 enclOp, protAccess,
1174 refSuper);
1175 JCExpression receiver = make.Select(
1176 base != null ? base : make.QualIdent(access.owner),
1177 access);
1178 return make.App(receiver, args);
1179
1180 // Other accesses to members of outer classes get a
1181 // qualifier.
1182 } else if (baseReq) {
1183 return make.at(tree.pos).Select(
1184 accessBase(tree.pos(), sym), sym).setType(tree.type);
1185 }
1186 }
1187 }
1188 }
1189 return tree;
1190 }
1191
1192 /** Ensure that identifier is accessible, return tree accessing the identifier.
1193 * @param tree The identifier tree.
1194 */
1195 JCExpression access(JCExpression tree) {
1196 Symbol sym = TreeInfo.symbol(tree);
1197 return sym == null ? tree : access(sym, tree, null, false);
1198 }
1199
1200 /** Return access constructor for a private constructor,
1201 * or the constructor itself, if no access constructor is needed.
1202 * @param pos The position to report diagnostics, if any.
1203 * @param constr The private constructor.
1204 */
1205 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) {
1206 if (needsPrivateAccess(constr)) {
1207 ClassSymbol accOwner = constr.owner.enclClass();
1208 MethodSymbol aconstr = accessConstrs.get(constr);
1209 if (aconstr == null) {
1210 List<Type> argtypes = constr.type.getParameterTypes();
1211 if ((accOwner.flags_field & ENUM) != 0)
1212 argtypes = argtypes
1213 .prepend(syms.intType)
1214 .prepend(syms.stringType);
1215 aconstr = new MethodSymbol(
1216 SYNTHETIC,
1217 names.init,
1218 new MethodType(
1219 argtypes.append(
1220 accessConstructorTag().erasure(types)),
1221 constr.type.getReturnType(),
1222 constr.type.getThrownTypes(),
1223 syms.methodClass),
1224 accOwner);
1225 enterSynthetic(pos, aconstr, accOwner.members());
1226 accessConstrs.put(constr, aconstr);
1227 accessed.append(constr);
1228 }
1229 return aconstr;
1230 } else {
1231 return constr;
1232 }
1233 }
1234
1235 /** Return an anonymous class nested in this toplevel class.
1236 */
1237 ClassSymbol accessConstructorTag() {
1238 ClassSymbol topClass = currentClass.outermostClass();
1239 ModuleSymbol topModle = topClass.packge().modle;
1240 for (int i = 1; ; i++) {
1241 Name flatname = names.fromString("" + topClass.getQualifiedName() +
1242 target.syntheticNameChar() +
1243 i);
1244 ClassSymbol ctag = chk.getCompiled(topModle, flatname);
1245 if (ctag == null)
1246 ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym;
1247 else if (!ctag.isAnonymous())
1248 continue;
1249 // keep a record of all tags, to verify that all are generated as required
1250 accessConstrTags = accessConstrTags.prepend(ctag);
1251 return ctag;
1252 }
1253 }
1254
1255 /** Add all required access methods for a private symbol to enclosing class.
1256 * @param sym The symbol.
1257 */
1258 void makeAccessible(Symbol sym) {
1259 JCClassDecl cdef = classDef(sym.owner.enclClass());
1260 if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner);
1261 if (sym.name == names.init) {
1262 cdef.defs = cdef.defs.prepend(
1263 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym)));
1264 } else {
1265 MethodSymbol[] accessors = accessSyms.get(sym);
1266 for (int i = 0; i < AccessCode.numberOfAccessCodes; i++) {
1267 if (accessors[i] != null)
1268 cdef.defs = cdef.defs.prepend(
1269 accessDef(cdef.pos, sym, accessors[i], i));
1270 }
1271 }
1272 }
1273
1274 /** Construct definition of an access method.
1275 * @param pos The source code position of the definition.
1276 * @param vsym The private or protected symbol.
1277 * @param accessor The access method for the symbol.
1278 * @param acode The access code.
1279 */
1280 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) {
1281 // System.err.println("access " + vsym + " with " + accessor);//DEBUG
1282 currentClass = vsym.owner.enclClass();
1283 make.at(pos);
1284 JCMethodDecl md = make.MethodDef(accessor, null);
1285
1286 // Find actual symbol
1287 Symbol sym = actualSymbols.get(vsym);
1288 if (sym == null) sym = vsym;
1289
1290 JCExpression ref; // The tree referencing the private symbol.
1291 List<JCExpression> args; // Any additional arguments to be passed along.
1292 if ((sym.flags() & STATIC) != 0) {
1293 ref = make.Ident(sym);
1294 args = make.Idents(md.params);
1295 } else {
1296 JCExpression site = make.Ident(md.params.head);
1297 if (acode % 2 != 0) {
1298 //odd access codes represent qualified super accesses - need to
1299 //emit reference to the direct superclass, even if the referred
1300 //member is from an indirect superclass (JLS 13.1)
1301 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type)));
1302 }
1303 ref = make.Select(site, sym);
1304 args = make.Idents(md.params.tail);
1305 }
1306 JCStatement stat; // The statement accessing the private symbol.
1307 if (sym.kind == VAR) {
1308 // Normalize out all odd access codes by taking floor modulo 2:
1309 int acode1 = acode - (acode & 1);
1310
1311 JCExpression expr; // The access method's return value.
1312 AccessCode aCode = AccessCode.getFromCode(acode1);
1313 switch (aCode) {
1314 case DEREF:
1315 expr = ref;
1316 break;
1317 case ASSIGN:
1318 expr = make.Assign(ref, args.head);
1319 break;
1320 case PREINC: case POSTINC: case PREDEC: case POSTDEC:
1321 expr = makeUnary(aCode.tag, ref);
1322 break;
1323 default:
1324 expr = make.Assignop(
1325 treeTag(binaryAccessOperator(acode1, JCTree.Tag.NO_TAG)), ref, args.head);
1326 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1, JCTree.Tag.NO_TAG);
1327 }
1328 stat = make.Return(expr.setType(sym.type));
1329 } else {
1330 stat = make.Call(make.App(ref, args));
1331 }
1332 md.body = make.Block(0, List.of(stat));
1333
1334 // Make sure all parameters, result types and thrown exceptions
1335 // are accessible.
1336 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail)
1337 l.head.vartype = access(l.head.vartype);
1338 md.restype = access(md.restype);
1339 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail)
1340 l.head = access(l.head);
1341
1342 return md;
1343 }
1344
1345 /** Construct definition of an access constructor.
1346 * @param pos The source code position of the definition.
1347 * @param constr The private constructor.
1348 * @param accessor The access method for the constructor.
1349 */
1350 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) {
1351 make.at(pos);
1352 JCMethodDecl md = make.MethodDef(accessor,
1353 accessor.externalType(types),
1354 null);
1355 JCIdent callee = make.Ident(names._this);
1356 callee.sym = constr;
1357 callee.type = constr.type;
1358 md.body =
1359 make.Block(0, List.of(
1360 make.Call(
1361 make.App(
1362 callee,
1363 make.Idents(md.params.reverse().tail.reverse())))));
1364 return md;
1365 }
1366
1367 /* ************************************************************************
1368 * Free variables proxies and this$n
1369 *************************************************************************/
1370
1371 /** A map which allows to retrieve the translated proxy variable for any given symbol of an
1372 * enclosing scope that is accessed (the accessed symbol could be the synthetic 'this$n' symbol).
1373 * Inside a constructor, the map temporarily overrides entries corresponding to proxies and any
1374 * 'this$n' symbols, where they represent the constructor parameters.
1375 */
1376 Map<Symbol, Symbol> proxies;
1377
1378 /** A scope containing all unnamed resource variables/saved
1379 * exception variables for translated TWR blocks
1380 */
1381 WriteableScope twrVars;
1382
1383 /** A stack containing the this$n field of the currently translated
1384 * classes (if needed) in innermost first order.
1385 * Inside a constructor, proxies and any this$n symbol are duplicated
1386 * in an additional innermost scope, where they represent the constructor
1387 * parameters.
1388 */
1389 List<VarSymbol> outerThisStack;
1390
1391 /** The name of a free variable proxy.
1392 */
1393 Name proxyName(Name name, int index) {
1394 Name proxyName = names.fromString("val" + target.syntheticNameChar() + name);
1395 if (index > 0) {
1396 proxyName = proxyName.append(names.fromString("" + target.syntheticNameChar() + index));
1397 }
1398 return proxyName;
1399 }
1400
1401 /** Proxy definitions for all free variables in given list, in reverse order.
1402 * @param pos The source code position of the definition.
1403 * @param freevars The free variables.
1404 * @param owner The class in which the definitions go.
1405 */
1406 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) {
1407 return freevarDefs(pos, freevars, owner, LOCAL_CAPTURE_FIELD);
1408 }
1409
1410 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner,
1411 long additionalFlags) {
1412 long flags = FINAL | SYNTHETIC | additionalFlags;
1413 List<JCVariableDecl> defs = List.nil();
1414 Set<Name> proxyNames = new HashSet<>();
1415 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) {
1416 VarSymbol v = l.head;
1417 int index = 0;
1418 Name proxyName;
1419 do {
1420 proxyName = proxyName(v.name, index++);
1421 } while (!proxyNames.add(proxyName));
1422 VarSymbol proxy = new VarSymbol(
1423 flags, proxyName, v.erasure(types), owner) {
1424 @Override
1425 public Symbol baseSymbol() {
1426 return v;
1427 }
1428 };
1429 proxies.put(v, proxy);
1430 JCVariableDecl vd = make.at(pos).VarDef(proxy, null);
1431 vd.vartype = access(vd.vartype);
1432 defs = defs.prepend(vd);
1433 }
1434 return defs;
1435 }
1436
1437 /** The name of a this$n field
1438 * @param type The class referenced by the this$n field
1439 */
1440 Name outerThisName(Type type, Symbol owner) {
1441 Type t = type.getEnclosingType();
1442 int nestingLevel = 0;
1443 while (t.hasTag(CLASS)) {
1444 t = t.getEnclosingType();
1445 nestingLevel++;
1446 }
1447 Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel);
1448 while (owner.kind == TYP && ((ClassSymbol)owner).members().findFirst(result) != null)
1449 result = names.fromString(result.toString() + target.syntheticNameChar());
1450 return result;
1451 }
1452
1453 private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) {
1454 Type target = owner.innermostAccessibleEnclosingClass().erasure(types);
1455 // Set NOOUTERTHIS for all synthetic outer instance variables, and unset
1456 // it when the variable is accessed. If the variable is never accessed,
1457 // we skip creating an outer instance field and saving the constructor
1458 // parameter to it.
1459 VarSymbol outerThis =
1460 new VarSymbol(flags | NOOUTERTHIS, outerThisName(target, owner), target, owner);
1461 outerThisStack = outerThisStack.prepend(outerThis);
1462 return outerThis;
1463 }
1464
1465 private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) {
1466 JCVariableDecl vd = make.at(pos).VarDef(sym, null);
1467 vd.vartype = access(vd.vartype);
1468 return vd;
1469 }
1470
1471 /** Definition for this$n field.
1472 * @param pos The source code position of the definition.
1473 * @param owner The method in which the definition goes.
1474 */
1475 JCVariableDecl outerThisDef(int pos, MethodSymbol owner) {
1476 ClassSymbol c = owner.enclClass();
1477 boolean isMandated =
1478 // Anonymous constructors
1479 (owner.isConstructor() && owner.isAnonymous()) ||
1480 // Constructors of non-private inner member classes
1481 (owner.isConstructor() && c.isInner() &&
1482 !c.isPrivate() && !c.isStatic());
1483 long flags =
1484 FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER;
1485 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags);
1486 owner.extraParams = owner.extraParams.prepend(outerThis);
1487 return makeOuterThisVarDecl(pos, outerThis);
1488 }
1489
1490 /** Definition for this$n field.
1491 * @param pos The source code position of the definition.
1492 * @param owner The class in which the definition goes.
1493 */
1494 JCVariableDecl outerThisDef(int pos, ClassSymbol owner) {
1495 VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC);
1496 return makeOuterThisVarDecl(pos, outerThis);
1497 }
1498
1499 /** Return a list of trees that load the free variables in given list,
1500 * in reverse order.
1501 * @param pos The source code position to be used for the trees.
1502 * @param freevars The list of free variables.
1503 */
1504 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) {
1505 List<JCExpression> args = List.nil();
1506 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail)
1507 args = args.prepend(loadFreevar(pos, l.head));
1508 return args;
1509 }
1510 //where
1511 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) {
1512 return access(v, make.at(pos).Ident(v), null, false);
1513 }
1514
1515 /** Construct a tree simulating the expression {@code C.this}.
1516 * @param pos The source code position to be used for the tree.
1517 * @param c The qualifier class.
1518 */
1519 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) {
1520 if (currentClass == c) {
1521 // in this case, `this' works fine
1522 return make.at(pos).This(c.erasure(types));
1523 } else {
1524 // need to go via this$n
1525 return makeOuterThis(pos, c);
1526 }
1527 }
1528
1529 /**
1530 * Optionally replace a try statement with the desugaring of a
1531 * try-with-resources statement. The canonical desugaring of
1532 *
1533 * try ResourceSpecification
1534 * Block
1535 *
1536 * is
1537 *
1538 * {
1539 * final VariableModifiers_minus_final R #resource = Expression;
1540 *
1541 * try ResourceSpecificationtail
1542 * Block
1543 * } body-only-finally {
1544 * if (#resource != null) //nullcheck skipped if Expression is provably non-null
1545 * #resource.close();
1546 * } catch (Throwable #primaryException) {
1547 * if (#resource != null) //nullcheck skipped if Expression is provably non-null
1548 * try {
1549 * #resource.close();
1550 * } catch (Throwable #suppressedException) {
1551 * #primaryException.addSuppressed(#suppressedException);
1552 * }
1553 * throw #primaryException;
1554 * }
1555 * }
1556 *
1557 * @param tree The try statement to inspect.
1558 * @return a desugared try-with-resources tree, or the original
1559 * try block if there are no resources to manage.
1560 */
1561 JCTree makeTwrTry(JCTry tree) {
1562 make_at(tree.pos());
1563 twrVars = twrVars.dup();
1564 JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body, 0);
1565 if (tree.catchers.isEmpty() && tree.finalizer == null)
1566 result = translate(twrBlock);
1567 else
1568 result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer));
1569 twrVars = twrVars.leave();
1570 return result;
1571 }
1572
1573 private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block, int depth) {
1574 if (resources.isEmpty())
1575 return block;
1576
1577 // Add resource declaration or expression to block statements
1578 ListBuffer<JCStatement> stats = new ListBuffer<>();
1579 JCTree resource = resources.head;
1580 JCExpression resourceUse;
1581 boolean resourceNonNull;
1582 if (resource instanceof JCVariableDecl variableDecl) {
1583 resourceUse = make.Ident(variableDecl.sym).setType(resource.type);
1584 resourceNonNull = variableDecl.init != null && TreeInfo.skipParens(variableDecl.init).hasTag(NEWCLASS);
1585 stats.add(variableDecl);
1586 } else {
1587 Assert.check(resource instanceof JCExpression);
1588 VarSymbol syntheticTwrVar =
1589 new VarSymbol(SYNTHETIC | FINAL,
1590 makeSyntheticName(names.fromString("twrVar" +
1591 depth), twrVars),
1592 (resource.type.hasTag(BOT)) ?
1593 syms.autoCloseableType : resource.type,
1594 currentMethodSym);
1595 twrVars.enter(syntheticTwrVar);
1596 JCVariableDecl syntheticTwrVarDecl =
1597 make.VarDef(syntheticTwrVar, (JCExpression)resource);
1598 resourceUse = (JCExpression)make.Ident(syntheticTwrVar);
1599 resourceNonNull = false;
1600 stats.add(syntheticTwrVarDecl);
1601 }
1602
1603 //create (semi-) finally block that will be copied into the main try body:
1604 int oldPos = make.pos;
1605 make.at(TreeInfo.endPos(block));
1606
1607 // if (#resource != null) { #resource.close(); }
1608 JCStatement bodyCloseStatement = makeResourceCloseInvocation(resourceUse);
1609
1610 if (!resourceNonNull) {
1611 bodyCloseStatement = make.If(makeNonNullCheck(resourceUse),
1612 bodyCloseStatement,
1613 null);
1614 }
1615
1616 JCBlock finallyClause = make.Block(BODY_ONLY_FINALIZE, List.of(bodyCloseStatement));
1617 make.at(oldPos);
1618
1619 // Create catch clause that saves exception, closes the resource and then rethrows the exception:
1620 VarSymbol primaryException =
1621 new VarSymbol(FINAL|SYNTHETIC,
1622 names.fromString("t" +
1623 target.syntheticNameChar()),
1624 syms.throwableType,
1625 currentMethodSym);
1626 JCVariableDecl primaryExceptionDecl = make.VarDef(primaryException, null);
1627
1628 // close resource:
1629 // try {
1630 // #resource.close();
1631 // } catch (Throwable #suppressedException) {
1632 // #primaryException.addSuppressed(#suppressedException);
1633 // }
1634 VarSymbol suppressedException =
1635 new VarSymbol(SYNTHETIC, make.paramName(2),
1636 syms.throwableType,
1637 currentMethodSym);
1638 JCStatement addSuppressedStatement =
1639 make.Exec(makeCall(make.Ident(primaryException),
1640 names.addSuppressed,
1641 List.of(make.Ident(suppressedException))));
1642 JCBlock closeResourceTryBlock =
1643 make.Block(0L, List.of(makeResourceCloseInvocation(resourceUse)));
1644 JCVariableDecl catchSuppressedDecl = make.VarDef(suppressedException, null);
1645 JCBlock catchSuppressedBlock = make.Block(0L, List.of(addSuppressedStatement));
1646 List<JCCatch> catchSuppressedClauses =
1647 List.of(make.Catch(catchSuppressedDecl, catchSuppressedBlock));
1648 JCTry closeResourceTry = make.Try(closeResourceTryBlock, catchSuppressedClauses, null);
1649 closeResourceTry.finallyCanCompleteNormally = true;
1650
1651 JCStatement exceptionalCloseStatement = closeResourceTry;
1652
1653 if (!resourceNonNull) {
1654 // if (#resource != null) { }
1655 exceptionalCloseStatement = make.If(makeNonNullCheck(resourceUse),
1656 exceptionalCloseStatement,
1657 null);
1658 }
1659
1660 JCStatement exceptionalRethrow = make.Throw(make.Ident(primaryException));
1661 JCBlock exceptionalCloseBlock = make.Block(0L, List.of(exceptionalCloseStatement, exceptionalRethrow));
1662 JCCatch exceptionalCatchClause = make.Catch(primaryExceptionDecl, exceptionalCloseBlock);
1663
1664 //create the main try statement with the close:
1665 JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block, depth + 1),
1666 List.of(exceptionalCatchClause),
1667 finallyClause);
1668
1669 outerTry.finallyCanCompleteNormally = true;
1670 stats.add(outerTry);
1671
1672 JCBlock newBlock = make.Block(0L, stats.toList());
1673 return newBlock;
1674 }
1675
1676 private JCStatement makeResourceCloseInvocation(JCExpression resource) {
1677 // convert to AutoCloseable if needed
1678 if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) {
1679 resource = convert(resource, syms.autoCloseableType);
1680 }
1681
1682 // create resource.close() method invocation
1683 JCExpression resourceClose = makeCall(resource,
1684 names.close,
1685 List.nil());
1686 return make.Exec(resourceClose);
1687 }
1688
1689 private JCExpression makeNonNullCheck(JCExpression expression) {
1690 return makeBinary(NE, expression, makeNull());
1691 }
1692
1693 /** Construct a tree that represents the outer instance
1694 * {@code C.this}. Never pick the current `this'.
1695 * @param pos The source code position to be used for the tree.
1696 * @param c The qualifier class.
1697 */
1698 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) {
1699 List<VarSymbol> ots = outerThisStack;
1700 if (ots.isEmpty()) {
1701 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1702 return makeNull();
1703 }
1704 VarSymbol ot = ots.head;
1705 JCExpression tree = access(make.at(pos).Ident(ot));
1706 ot.flags_field &= ~NOOUTERTHIS;
1707 TypeSymbol otc = ot.type.tsym;
1708 while (otc != c) {
1709 do {
1710 ots = ots.tail;
1711 if (ots.isEmpty()) {
1712 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1713 Assert.error(); // should have been caught in Attr
1714 return tree;
1715 }
1716 ot = ots.head;
1717 } while (ot.owner != otc);
1718 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) {
1719 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1720 Assert.error(); // should have been caught in Attr
1721 return makeNull();
1722 }
1723 tree = access(make.at(pos).Select(tree, ot));
1724 ot.flags_field &= ~NOOUTERTHIS;
1725 otc = ot.type.tsym;
1726 }
1727 return tree;
1728 }
1729
1730 /** Construct a tree that represents the closest outer instance
1731 * {@code C.this} such that the given symbol is a member of C.
1732 * @param pos The source code position to be used for the tree.
1733 * @param sym The accessed symbol.
1734 * @param preciseMatch should we accept a type that is a subtype of
1735 * sym's owner, even if it doesn't contain sym
1736 * due to hiding, overriding, or non-inheritance
1737 * due to protection?
1738 */
1739 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1740 if (preciseMatch ? sym.isMemberOf(currentClass, types)
1741 : currentClass.isSubClass(sym.owner, types)) {
1742 // in this case, `this' works fine
1743 return make.at(pos).This(currentClass.erasure(types));
1744 } else {
1745 // need to go via this$n
1746 return makeOwnerThisN(pos, sym, preciseMatch);
1747 }
1748 }
1749
1750 /**
1751 * Similar to makeOwnerThis but will never pick "this".
1752 */
1753 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1754 Symbol c = sym.owner;
1755 List<VarSymbol> ots = outerThisStack;
1756 if (ots.isEmpty()) {
1757 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1758 return makeNull();
1759 }
1760 VarSymbol ot = ots.head;
1761 JCExpression tree = access(make.at(pos).Ident(ot));
1762 ot.flags_field &= ~NOOUTERTHIS;
1763 TypeSymbol otc = ot.type.tsym;
1764 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) {
1765 do {
1766 ots = ots.tail;
1767 if (ots.isEmpty()) {
1768 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1769 return tree;
1770 }
1771 ot = ots.head;
1772 } while (ot.owner != otc);
1773 tree = access(make.at(pos).Select(tree, ot));
1774 ot.flags_field &= ~NOOUTERTHIS;
1775 otc = ot.type.tsym;
1776 }
1777 return tree;
1778 }
1779
1780 /** Return tree simulating the assignment {@code this.name = name}, where
1781 * name is the name of a free variable.
1782 */
1783 JCStatement initField(int pos, Symbol rhs, Symbol lhs) {
1784 Assert.check(rhs.owner.kind == MTH);
1785 Assert.check(rhs.owner.owner == lhs.owner);
1786 make.at(pos);
1787 return
1788 make.Exec(
1789 make.Assign(
1790 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1791 make.Ident(rhs)).setType(lhs.erasure(types)));
1792 }
1793
1794 /**
1795 * Return tree simulating null checking outer this and/or assigning. This is
1796 * called when a null check is required (nullCheckOuterThis), or a synthetic
1797 * field is generated (stores).
1798 */
1799 JCStatement initOuterThis(int pos, VarSymbol rhs, boolean stores) {
1800 Assert.check(rhs.owner.kind == MTH);
1801 Assert.check(nullCheckOuterThis || stores); // One of the flags must be true
1802 make.at(pos);
1803 JCExpression expression = make.Ident(rhs);
1804 if (nullCheckOuterThis) {
1805 expression = attr.makeNullCheck(expression);
1806 }
1807 if (stores) {
1808 VarSymbol lhs = outerThisStack.head;
1809 Assert.check(rhs.owner.owner == lhs.owner);
1810 expression = make.Assign(
1811 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1812 expression).setType(lhs.erasure(types));
1813 }
1814 return make.Exec(expression);
1815 }
1816
1817 /* ************************************************************************
1818 * Code for .class
1819 *************************************************************************/
1820
1821 /** Return the symbol of a class to contain a cache of
1822 * compiler-generated statics such as class$ and the
1823 * $assertionsDisabled flag. We create an anonymous nested class
1824 * (unless one already exists) and return its symbol. However,
1825 * for backward compatibility in 1.4 and earlier we use the
1826 * top-level class itself.
1827 */
1828 private ClassSymbol outerCacheClass() {
1829 ClassSymbol clazz = outermostClassDef.sym;
1830 Scope s = clazz.members();
1831 for (Symbol sym : s.getSymbols(NON_RECURSIVE))
1832 if (sym.kind == TYP &&
1833 sym.name == names.empty &&
1834 (sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym;
1835 return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym;
1836 }
1837
1838 /** Create an attributed tree of the form left.name(). */
1839 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) {
1840 Assert.checkNonNull(left.type);
1841 Symbol funcsym = lookupMethod(make_pos, name, left.type,
1842 TreeInfo.types(args));
1843 return make.App(make.Select(left, funcsym), args);
1844 }
1845
1846 /** The tree simulating a T.class expression.
1847 * @param clazz The tree identifying type T.
1848 */
1849 private JCExpression classOf(JCTree clazz) {
1850 return classOfType(clazz.type, clazz.pos());
1851 }
1852
1853 private JCExpression classOfType(Type type, DiagnosticPosition pos) {
1854 switch (type.getTag()) {
1855 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT:
1856 case DOUBLE: case BOOLEAN: case VOID:
1857 // replace with <BoxedClass>.TYPE
1858 ClassSymbol c = types.boxedClass(type);
1859 Symbol typeSym =
1860 rs.accessBase(
1861 rs.findIdentInType(pos, attrEnv, c.type, names.TYPE, KindSelector.VAR),
1862 pos, c.type, names.TYPE, true);
1863 if (typeSym.kind == VAR)
1864 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated
1865 return make.QualIdent(typeSym);
1866 case CLASS: case ARRAY:
1867 VarSymbol sym = new VarSymbol(
1868 STATIC | PUBLIC | FINAL, names._class,
1869 syms.classType, type.tsym);
1870 return make_at(pos).Select(make.Type(type), sym);
1871 default:
1872 throw new AssertionError();
1873 }
1874 }
1875
1876 /* ************************************************************************
1877 * Code for enabling/disabling assertions.
1878 *************************************************************************/
1879
1880 private ClassSymbol assertionsDisabledClassCache;
1881
1882 /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces.
1883 */
1884 private ClassSymbol assertionsDisabledClass() {
1885 if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache;
1886
1887 assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym;
1888
1889 return assertionsDisabledClassCache;
1890 }
1891
1892 // This code is not particularly robust if the user has
1893 // previously declared a member named '$assertionsDisabled'.
1894 // The same faulty idiom also appears in the translation of
1895 // class literals above. We should report an error if a
1896 // previous declaration is not synthetic.
1897
1898 private JCExpression assertFlagTest(DiagnosticPosition pos) {
1899 // Outermost class may be either true class or an interface.
1900 ClassSymbol outermostClass = outermostClassDef.sym;
1901
1902 //only classes can hold a non-public field, look for a usable one:
1903 ClassSymbol container = !currentClass.isInterface() ? currentClass :
1904 assertionsDisabledClass();
1905
1906 VarSymbol assertDisabledSym =
1907 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled,
1908 container.members());
1909 if (assertDisabledSym == null) {
1910 assertDisabledSym =
1911 new VarSymbol(STATIC | FINAL | SYNTHETIC,
1912 dollarAssertionsDisabled,
1913 syms.booleanType,
1914 container);
1915 enterSynthetic(pos, assertDisabledSym, container.members());
1916 Symbol desiredAssertionStatusSym = lookupMethod(pos,
1917 names.desiredAssertionStatus,
1918 types.erasure(syms.classType),
1919 List.nil());
1920 JCClassDecl containerDef = classDef(container);
1921 make_at(containerDef.pos());
1922 JCExpression notStatus = makeUnary(NOT, make.App(make.Select(
1923 classOfType(types.erasure(outermostClass.type),
1924 containerDef.pos()),
1925 desiredAssertionStatusSym)));
1926 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym,
1927 notStatus);
1928 containerDef.defs = containerDef.defs.prepend(assertDisabledDef);
1929
1930 if (currentClass.isInterface()) {
1931 //need to load the assertions enabled/disabled state while
1932 //initializing the interface:
1933 JCClassDecl currentClassDef = classDef(currentClass);
1934 make_at(currentClassDef.pos());
1935 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null);
1936 JCBlock clinit = make.Block(STATIC, List.of(dummy));
1937 currentClassDef.defs = currentClassDef.defs.prepend(clinit);
1938 }
1939 }
1940 make_at(pos);
1941 return makeUnary(NOT, make.Ident(assertDisabledSym));
1942 }
1943
1944
1945 /* ************************************************************************
1946 * Building blocks for let expressions
1947 *************************************************************************/
1948
1949 interface TreeBuilder {
1950 JCExpression build(JCExpression arg);
1951 }
1952
1953 /** Construct an expression using the builder, with the given rval
1954 * expression as an argument to the builder. However, the rval
1955 * expression must be computed only once, even if used multiple
1956 * times in the result of the builder. We do that by
1957 * constructing a "let" expression that saves the rvalue into a
1958 * temporary variable and then uses the temporary variable in
1959 * place of the expression built by the builder. The complete
1960 * resulting expression is of the form
1961 * <pre>
1962 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>;
1963 * in (<b>BUILDER</b>(<b>TEMP</b>)))
1964 * </pre>
1965 * where <code><b>TEMP</b></code> is a newly declared variable
1966 * in the let expression.
1967 */
1968 JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) {
1969 rval = TreeInfo.skipParens(rval);
1970 switch (rval.getTag()) {
1971 case LITERAL:
1972 return builder.build(rval);
1973 case IDENT:
1974 JCIdent id = (JCIdent) rval;
1975 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH)
1976 return builder.build(rval);
1977 }
1978 Name name = TreeInfo.name(rval);
1979 if (name == names._super || name == names._this)
1980 return builder.build(rval);
1981 VarSymbol var =
1982 new VarSymbol(FINAL|SYNTHETIC,
1983 names.fromString(
1984 target.syntheticNameChar()
1985 + "" + rval.hashCode()),
1986 type,
1987 currentMethodSym);
1988 rval = convert(rval,type);
1989 JCVariableDecl def = make.VarDef(var, rval); // XXX cast
1990 JCExpression built = builder.build(make.Ident(var));
1991 JCExpression res = make.LetExpr(def, built);
1992 res.type = built.type;
1993 return res;
1994 }
1995
1996 // same as above, with the type of the temporary variable computed
1997 JCExpression abstractRval(JCExpression rval, TreeBuilder builder) {
1998 return abstractRval(rval, rval.type, builder);
1999 }
2000
2001 // same as above, but for an expression that may be used as either
2002 // an rvalue or an lvalue. This requires special handling for
2003 // Select expressions, where we place the left-hand-side of the
2004 // select in a temporary, and for Indexed expressions, where we
2005 // place both the indexed expression and the index value in temps.
2006 JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) {
2007 lval = TreeInfo.skipParens(lval);
2008 switch (lval.getTag()) {
2009 case IDENT:
2010 return builder.build(lval);
2011 case SELECT: {
2012 final JCFieldAccess s = (JCFieldAccess)lval;
2013 Symbol lid = TreeInfo.symbol(s.selected);
2014 if (lid != null && lid.kind == TYP) return builder.build(lval);
2015 return abstractRval(s.selected, selected -> builder.build(make.Select(selected, s.sym)));
2016 }
2017 case INDEXED: {
2018 final JCArrayAccess i = (JCArrayAccess)lval;
2019 return abstractRval(i.indexed, indexed -> abstractRval(i.index, syms.intType, index -> {
2020 JCExpression newLval = make.Indexed(indexed, index);
2021 newLval.setType(i.type);
2022 return builder.build(newLval);
2023 }));
2024 }
2025 case TYPECAST: {
2026 return abstractLval(((JCTypeCast)lval).expr, builder);
2027 }
2028 }
2029 throw new AssertionError(lval);
2030 }
2031
2032 // evaluate and discard the first expression, then evaluate the second.
2033 JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) {
2034 JCExpression res = make.LetExpr(List.of(make.Exec(expr1)), expr2);
2035 res.type = expr2.type;
2036 return res;
2037 }
2038
2039 /* ************************************************************************
2040 * Translation methods
2041 *************************************************************************/
2042
2043 /** Visitor argument: enclosing operator node.
2044 */
2045 private JCExpression enclOp;
2046
2047 /** Visitor method: Translate a single node.
2048 * Attach the source position from the old tree to its replacement tree.
2049 */
2050 @Override
2051 public <T extends JCTree> T translate(T tree) {
2052 if (tree == null) {
2053 return null;
2054 } else {
2055 make_at(tree.pos());
2056 T result = super.translate(tree);
2057 if (result != null && result != tree) {
2058 result.endpos = tree.endpos;
2059 }
2060 return result;
2061 }
2062 }
2063
2064 /** Visitor method: Translate a single node, boxing or unboxing if needed.
2065 */
2066 public <T extends JCExpression> T translate(T tree, Type type) {
2067 return (tree == null) ? null : boxIfNeeded(translate(tree), type);
2068 }
2069
2070 /** Visitor method: Translate tree.
2071 */
2072 public <T extends JCTree> T translate(T tree, JCExpression enclOp) {
2073 JCExpression prevEnclOp = this.enclOp;
2074 this.enclOp = enclOp;
2075 T res = translate(tree);
2076 this.enclOp = prevEnclOp;
2077 return res;
2078 }
2079
2080 /** Visitor method: Translate list of trees.
2081 */
2082 public <T extends JCExpression> List<T> translate(List<T> trees, Type type) {
2083 if (trees == null) return null;
2084 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
2085 l.head = translate(l.head, type);
2086 return trees;
2087 }
2088
2089 public void visitPackageDef(JCPackageDecl tree) {
2090 if (!needPackageInfoClass(tree))
2091 return;
2092
2093 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2094 // package-info is marked SYNTHETIC in JDK 1.6 and later releases
2095 flags = flags | Flags.SYNTHETIC;
2096 ClassSymbol c = tree.packge.package_info;
2097 c.setAttributes(tree.packge);
2098 c.flags_field |= flags;
2099 ClassType ctype = (ClassType) c.type;
2100 ctype.supertype_field = syms.objectType;
2101 ctype.interfaces_field = List.nil();
2102 createInfoClass(tree.annotations, c);
2103 }
2104 // where
2105 private boolean needPackageInfoClass(JCPackageDecl pd) {
2106 switch (pkginfoOpt) {
2107 case ALWAYS:
2108 return true;
2109 case LEGACY:
2110 return pd.getAnnotations().nonEmpty();
2111 case NONEMPTY:
2112 for (Attribute.Compound a :
2113 pd.packge.getDeclarationAttributes()) {
2114 Attribute.RetentionPolicy p = types.getRetention(a);
2115 if (p != Attribute.RetentionPolicy.SOURCE)
2116 return true;
2117 }
2118 return false;
2119 }
2120 throw new AssertionError();
2121 }
2122
2123 public void visitModuleDef(JCModuleDecl tree) {
2124 ModuleSymbol msym = tree.sym;
2125 ClassSymbol c = msym.module_info;
2126 c.setAttributes(msym);
2127 c.flags_field |= Flags.MODULE;
2128 createInfoClass(List.nil(), tree.sym.module_info);
2129 }
2130
2131 private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) {
2132 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2133 JCClassDecl infoClass =
2134 make.ClassDef(make.Modifiers(flags, annots),
2135 c.name, List.nil(),
2136 null, List.nil(), List.nil());
2137 infoClass.sym = c;
2138 translated.append(infoClass);
2139 }
2140
2141 public void visitClassDef(JCClassDecl tree) {
2142 Env<AttrContext> prevEnv = attrEnv;
2143 ClassSymbol currentClassPrev = currentClass;
2144 MethodSymbol currentMethodSymPrev = currentMethodSym;
2145
2146 currentClass = tree.sym;
2147 currentMethodSym = null;
2148 attrEnv = typeEnvs.remove(currentClass);
2149 if (attrEnv == null)
2150 attrEnv = prevEnv;
2151
2152 classdefs.put(currentClass, tree);
2153
2154 Map<Symbol, Symbol> prevProxies = proxies;
2155 proxies = new HashMap<>(proxies);
2156 List<VarSymbol> prevOuterThisStack = outerThisStack;
2157
2158 // If this is an enum definition
2159 if ((tree.mods.flags & ENUM) != 0 &&
2160 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0)
2161 visitEnumDef(tree);
2162
2163 if ((tree.mods.flags & RECORD) != 0) {
2164 visitRecordDef(tree);
2165 }
2166
2167 // If this is a nested class, define a this$n field for
2168 // it and add to proxies.
2169 JCVariableDecl otdef = null;
2170 if (currentClass.hasOuterInstance())
2171 otdef = outerThisDef(tree.pos, currentClass);
2172
2173 // If this is a local class, define proxies for all its free variables.
2174 List<JCVariableDecl> fvdefs = freevarDefs(
2175 tree.pos, freevars(currentClass), currentClass);
2176
2177 // Recursively translate superclass, interfaces.
2178 tree.extending = translate(tree.extending);
2179 tree.implementing = translate(tree.implementing);
2180
2181 if (currentClass.isDirectlyOrIndirectlyLocal()) {
2182 ClassSymbol encl = currentClass.owner.enclClass();
2183 if (encl.trans_local == null) {
2184 encl.trans_local = List.nil();
2185 }
2186 encl.trans_local = encl.trans_local.prepend(currentClass);
2187 }
2188
2189 // Recursively translate members, taking into account that new members
2190 // might be created during the translation and prepended to the member
2191 // list `tree.defs'.
2192 List<JCTree> seen = List.nil();
2193 while (tree.defs != seen) {
2194 List<JCTree> unseen = tree.defs;
2195 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) {
2196 JCTree outermostMemberDefPrev = outermostMemberDef;
2197 if (outermostMemberDefPrev == null) outermostMemberDef = l.head;
2198 l.head = translate(l.head);
2199 outermostMemberDef = outermostMemberDefPrev;
2200 }
2201 seen = unseen;
2202 }
2203
2204 // Convert a protected modifier to public, mask static modifier.
2205 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC;
2206 tree.mods.flags &= ClassFlags;
2207
2208 // Convert name to flat representation, replacing '.' by '$'.
2209 tree.name = Convert.shortName(currentClass.flatName());
2210
2211 // Add free variables proxy definitions to class.
2212
2213 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) {
2214 tree.defs = tree.defs.prepend(l.head);
2215 enterSynthetic(tree.pos(), l.head.sym, currentClass.members());
2216 }
2217 // If this$n was accessed, add the field definition and prepend
2218 // initializer code to any super() invocation to initialize it
2219 // otherwise prepend enclosing instance null check code if required
2220 emitOuter:
2221 if (currentClass.hasOuterInstance()) {
2222 boolean storesThis = shouldEmitOuterThis(currentClass);
2223 if (storesThis) {
2224 tree.defs = tree.defs.prepend(otdef);
2225 enterSynthetic(tree.pos(), otdef.sym, currentClass.members());
2226 } else if (!nullCheckOuterThis) {
2227 break emitOuter;
2228 }
2229
2230 for (JCTree def : tree.defs) {
2231 if (TreeInfo.isConstructor(def)) {
2232 JCMethodDecl mdef = (JCMethodDecl)def;
2233 if (TreeInfo.hasConstructorCall(mdef, names._super)) {
2234 List<JCStatement> initializer = List.of(initOuterThis(mdef.body.pos, mdef.params.head.sym, storesThis)) ;
2235 TreeInfo.mapSuperCalls(mdef.body, supercall -> make.Block(0, initializer.append(supercall)));
2236 }
2237 }
2238 }
2239 }
2240
2241 proxies = prevProxies;
2242 outerThisStack = prevOuterThisStack;
2243
2244 // Append translated tree to `translated' queue.
2245 translated.append(tree);
2246
2247 attrEnv = prevEnv;
2248 currentClass = currentClassPrev;
2249 currentMethodSym = currentMethodSymPrev;
2250
2251 // Return empty block {} as a placeholder for an inner class.
2252 result = make_at(tree.pos()).Block(SYNTHETIC, List.nil());
2253 }
2254
2255 private boolean shouldEmitOuterThis(ClassSymbol sym) {
2256 if (!optimizeOuterThis) {
2257 // Optimization is disabled
2258 return true;
2259 }
2260 if ((outerThisStack.head.flags_field & NOOUTERTHIS) == 0) {
2261 // Enclosing instance field is used
2262 return true;
2263 }
2264 if (rs.isSerializable(sym.type)) {
2265 // Class is serializable
2266 return true;
2267 }
2268 return false;
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 MethodSymbol 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(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 types.super();
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 MethodSymbol 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 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 Type prevRestype = currentRestype;
2654 JCMethodDecl prevMethodDef = currentMethodDef;
2655 MethodSymbol prevMethodSym = currentMethodSym;
2656 int prevVariableIndex = variableIndex;
2657 try {
2658 currentRestype = types.erasure(tree.type.getReturnType());
2659 currentMethodDef = tree;
2660 currentMethodSym = tree.sym;
2661 variableIndex = 0;
2662 visitMethodDefInternal(tree);
2663 } finally {
2664 currentRestype = prevRestype;
2665 currentMethodDef = prevMethodDef;
2666 currentMethodSym = prevMethodSym;
2667 variableIndex = prevVariableIndex;
2668 }
2669 }
2670
2671 private void visitMethodDefInternal(JCMethodDecl tree) {
2672 if (tree.name == names.init &&
2673 !currentClass.isStatic() &&
2674 (currentClass.isInner() || currentClass.isDirectlyOrIndirectlyLocal())) {
2675 // We are seeing a constructor of an inner class.
2676 MethodSymbol m = tree.sym;
2677
2678 // Push a new proxy scope for constructor parameters.
2679 // and create definitions for any this$n and proxy parameters.
2680 Map<Symbol, Symbol> prevProxies = proxies;
2681 proxies = new HashMap<>(proxies);
2682 List<VarSymbol> prevOuterThisStack = outerThisStack;
2683 List<VarSymbol> fvs = freevars(currentClass);
2684 JCVariableDecl otdef = null;
2685 if (currentClass.hasOuterInstance())
2686 otdef = outerThisDef(tree.pos, m);
2687 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER);
2688
2689 // Recursively translate result type, parameters and thrown list.
2690 tree.restype = translate(tree.restype);
2691 tree.params = translateVarDefs(tree.params);
2692 tree.thrown = translate(tree.thrown);
2693
2694 // when compiling stubs, don't process body
2695 if (tree.body == null) {
2696 result = tree;
2697 return;
2698 }
2699
2700 // Add this$n (if needed) in front of and free variables behind
2701 // constructor parameter list.
2702 tree.params = tree.params.appendList(fvdefs);
2703 if (currentClass.hasOuterInstance()) {
2704 tree.params = tree.params.prepend(otdef);
2705 }
2706
2707 // Determine whether this constructor has a super() invocation
2708 boolean invokesSuper = TreeInfo.hasConstructorCall(tree, names._super);
2709
2710 // Create initializers for this$n and proxies
2711 ListBuffer<JCStatement> added = new ListBuffer<>();
2712 if (fvs.nonEmpty()) {
2713 List<Type> addedargtypes = List.nil();
2714 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
2715 m.capturedLocals =
2716 m.capturedLocals.prepend((VarSymbol)
2717 (proxies.get(l.head)));
2718 if (invokesSuper) {
2719 added = added.prepend(
2720 initField(tree.body.pos, proxies.get(l.head), prevProxies.get(l.head)));
2721 }
2722 addedargtypes = addedargtypes.prepend(l.head.erasure(types));
2723 }
2724 Type olderasure = m.erasure(types);
2725 m.erasure_field = new MethodType(
2726 olderasure.getParameterTypes().appendList(addedargtypes),
2727 olderasure.getReturnType(),
2728 olderasure.getThrownTypes(),
2729 syms.methodClass);
2730 }
2731
2732 // Recursively translate existing local statements
2733 tree.body.stats = translate(tree.body.stats);
2734
2735 // Prepend initializers in front of super() call
2736 if (added.nonEmpty()) {
2737 List<JCStatement> initializers = added.toList();
2738 TreeInfo.mapSuperCalls(tree.body, supercall -> make.Block(0, initializers.append(supercall)));
2739 }
2740
2741 // pop local variables from proxy stack
2742 proxies = prevProxies;
2743
2744 outerThisStack = prevOuterThisStack;
2745 } else {
2746 super.visitMethodDef(tree);
2747 }
2748 if (tree.name == names.init && ((tree.sym.flags_field & Flags.COMPACT_RECORD_CONSTRUCTOR) != 0 ||
2749 (tree.sym.flags_field & (GENERATEDCONSTR | RECORD)) == (GENERATEDCONSTR | RECORD))) {
2750 // lets find out if there is any field waiting to be initialized
2751 ListBuffer<VarSymbol> fields = new ListBuffer<>();
2752 for (Symbol sym : currentClass.getEnclosedElements()) {
2753 if (sym.kind == Kinds.Kind.VAR && ((sym.flags() & RECORD) != 0))
2754 fields.append((VarSymbol) sym);
2755 }
2756 for (VarSymbol field: fields) {
2757 if ((field.flags_field & Flags.UNINITIALIZED_FIELD) != 0) {
2758 VarSymbol param = tree.params.stream().filter(p -> p.name == field.name).findFirst().get().sym;
2759 make.at(tree.pos);
2760 tree.body.stats = tree.body.stats.append(
2761 make.Exec(
2762 make.Assign(
2763 make.Select(make.This(field.owner.erasure(types)), field),
2764 make.Ident(param)).setType(field.erasure(types))));
2765 // we don't need the flag at the field anymore
2766 field.flags_field &= ~Flags.UNINITIALIZED_FIELD;
2767 }
2768 }
2769 }
2770 result = tree;
2771 }
2772
2773 public void visitTypeCast(JCTypeCast tree) {
2774 tree.clazz = translate(tree.clazz);
2775 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive())
2776 tree.expr = translate(tree.expr, tree.type);
2777 else
2778 tree.expr = translate(tree.expr);
2779 result = tree;
2780 }
2781
2782 /**
2783 * All the exactness checks between primitive types that require a run-time
2784 * check are in {@code java.lang.runtime.ExactConversionsSupport}. Those methods
2785 * are in the form {@code ExactConversionsSupport.is<S>To<T>Exact} where both
2786 * {@code S} and {@code T} are primitive types and correspond to the runtime
2787 * action that will be executed to check whether a certain value (that is passed
2788 * as a parameter) can be converted to {@code T} without loss of information.
2789 *
2790 * Rewrite {@code instanceof if expr : Object} and Type is primitive type:
2791 *
2792 * {@snippet :
2793 * Object v = ...
2794 * if (v instanceof float)
2795 * =>
2796 * if (let tmp$123 = v; tmp$123 instanceof Float)
2797 * }
2798 *
2799 * Rewrite {@code instanceof if expr : wrapper reference type}
2800 *
2801 * {@snippet :
2802 * Integer v = ...
2803 * if (v instanceof float)
2804 * =>
2805 * if (let tmp$123 = v; tmp$123 != null && ExactConversionsSupport.intToFloatExact(tmp$123.intValue()))
2806 * }
2807 *
2808 * Rewrite {@code instanceof if expr : primitive}
2809 *
2810 * {@snippet :
2811 * int v = ...
2812 * if (v instanceof float)
2813 * =>
2814 * if (let tmp$123 = v; ExactConversionsSupport.intToFloatExact(tmp$123))
2815 * }
2816 *
2817 * More rewritings:
2818 * <ul>
2819 * <li>If the {@code instanceof} check is unconditionally exact rewrite to true.</li>
2820 * <li>If expression type is {@code Byte}, {@code Short}, {@code Integer}, ..., an
2821 * unboxing conversion followed by a widening primitive conversion.</li>
2822 * <li>If expression type is a supertype: {@code Number}, a narrowing reference
2823 * conversion followed by an unboxing conversion.</li>
2824 * </ul>
2825 */
2826 public void visitTypeTest(JCInstanceOf tree) {
2827 if (tree.expr.type.isPrimitive() || tree.pattern.type.isPrimitive()) {
2828 JCStatement prefixStatement;
2829 JCExpression exactnessCheck;
2830 JCExpression instanceOfExpr = translate(tree.expr);
2831
2832 if (types.isUnconditionallyExactTypeBased(tree.expr.type, tree.pattern.type)) {
2833 // instanceOfExpr; true
2834 prefixStatement = make.Exec(instanceOfExpr);
2835 exactnessCheck = make.Literal(BOOLEAN, 1).setType(syms.booleanType.constType(1));
2836 } else if (tree.expr.type.isPrimitive()) {
2837 // ExactConversionSupport.isXxxExact(instanceOfExpr)
2838 prefixStatement = null;
2839 exactnessCheck = getExactnessCheck(tree, instanceOfExpr);
2840 } else if (tree.expr.type.isReference()) {
2841 if (types.isUnconditionallyExactTypeBased(types.unboxedType(tree.expr.type), tree.pattern.type)) {
2842 // instanceOfExpr != null
2843 prefixStatement = null;
2844 exactnessCheck = makeBinary(NE, instanceOfExpr, makeNull());
2845 } else {
2846 // We read the result of instanceOfExpr, so create variable
2847 VarSymbol dollar_s = new VarSymbol(FINAL | SYNTHETIC,
2848 names.fromString("tmp" + variableIndex++ + this.target.syntheticNameChar()),
2849 types.erasure(tree.expr.type),
2850 currentMethodSym);
2851 prefixStatement = make.at(tree.pos())
2852 .VarDef(dollar_s, instanceOfExpr);
2853
2854 JCExpression nullCheck =
2855 makeBinary(NE,
2856 make.Ident(dollar_s),
2857 makeNull());
2858
2859 if (types.unboxedType(tree.expr.type).isPrimitive()) {
2860 exactnessCheck =
2861 makeBinary(AND,
2862 nullCheck,
2863 getExactnessCheck(tree, boxIfNeeded(make.Ident(dollar_s), types.unboxedType(tree.expr.type))));
2864 } else {
2865 exactnessCheck =
2866 makeBinary(AND,
2867 nullCheck,
2868 make.at(tree.pos())
2869 .TypeTest(make.Ident(dollar_s), make.Type(types.boxedClass(tree.pattern.type).type))
2870 .setType(syms.booleanType));
2871 }
2872 }
2873 } else {
2874 throw Assert.error("Non primitive or reference type: " + tree.expr.type);
2875 }
2876 result = (prefixStatement == null ? exactnessCheck : make.LetExpr(List.of(prefixStatement), exactnessCheck))
2877 .setType(syms.booleanType);
2878 } else {
2879 tree.expr = translate(tree.expr);
2880 tree.pattern = translate(tree.pattern);
2881 result = tree;
2882 }
2883 }
2884
2885 // TypePairs should be in sync with the corresponding record in SwitchBootstraps
2886 record TypePairs(TypeSymbol from, TypeSymbol to) {
2887 public static TypePairs of(Symtab syms, Type from, Type to) {
2888 if (from == syms.byteType || from == syms.shortType || from == syms.charType) {
2889 from = syms.intType;
2890 }
2891 return new TypePairs(from, to);
2892 }
2893
2894 public TypePairs(Type from, Type to) {
2895 this(from.tsym, to.tsym);
2896 }
2897
2898 public static HashMap<TypePairs, String> initialize(Symtab syms) {
2899 HashMap<TypePairs, String> typePairToName = new HashMap<>();
2900 typePairToName.put(new TypePairs(syms.byteType, syms.charType), "isIntToCharExact"); // redirected
2901 typePairToName.put(new TypePairs(syms.shortType, syms.byteType), "isIntToByteExact"); // redirected
2902 typePairToName.put(new TypePairs(syms.shortType, syms.charType), "isIntToCharExact"); // redirected
2903 typePairToName.put(new TypePairs(syms.charType, syms.byteType), "isIntToByteExact"); // redirected
2904 typePairToName.put(new TypePairs(syms.charType, syms.shortType), "isIntToShortExact"); // redirected
2905 typePairToName.put(new TypePairs(syms.intType, syms.byteType), "isIntToByteExact");
2906 typePairToName.put(new TypePairs(syms.intType, syms.shortType), "isIntToShortExact");
2907 typePairToName.put(new TypePairs(syms.intType, syms.charType), "isIntToCharExact");
2908 typePairToName.put(new TypePairs(syms.intType, syms.floatType), "isIntToFloatExact");
2909 typePairToName.put(new TypePairs(syms.longType, syms.byteType), "isLongToByteExact");
2910 typePairToName.put(new TypePairs(syms.longType, syms.shortType), "isLongToShortExact");
2911 typePairToName.put(new TypePairs(syms.longType, syms.charType), "isLongToCharExact");
2912 typePairToName.put(new TypePairs(syms.longType, syms.intType), "isLongToIntExact");
2913 typePairToName.put(new TypePairs(syms.longType, syms.floatType), "isLongToFloatExact");
2914 typePairToName.put(new TypePairs(syms.longType, syms.doubleType), "isLongToDoubleExact");
2915 typePairToName.put(new TypePairs(syms.floatType, syms.byteType), "isFloatToByteExact");
2916 typePairToName.put(new TypePairs(syms.floatType, syms.shortType), "isFloatToShortExact");
2917 typePairToName.put(new TypePairs(syms.floatType, syms.charType), "isFloatToCharExact");
2918 typePairToName.put(new TypePairs(syms.floatType, syms.intType), "isFloatToIntExact");
2919 typePairToName.put(new TypePairs(syms.floatType, syms.longType), "isFloatToLongExact");
2920 typePairToName.put(new TypePairs(syms.doubleType, syms.byteType), "isDoubleToByteExact");
2921 typePairToName.put(new TypePairs(syms.doubleType, syms.shortType), "isDoubleToShortExact");
2922 typePairToName.put(new TypePairs(syms.doubleType, syms.charType), "isDoubleToCharExact");
2923 typePairToName.put(new TypePairs(syms.doubleType, syms.intType), "isDoubleToIntExact");
2924 typePairToName.put(new TypePairs(syms.doubleType, syms.longType), "isDoubleToLongExact");
2925 typePairToName.put(new TypePairs(syms.doubleType, syms.floatType), "isDoubleToFloatExact");
2926 return typePairToName;
2927 }
2928 }
2929
2930 private JCExpression getExactnessCheck(JCInstanceOf tree, JCExpression argument) {
2931 TypePairs pair = TypePairs.of(syms, types.unboxedTypeOrType(tree.expr.type), tree.pattern.type);
2932
2933 Name exactnessFunction = names.fromString(typePairToName.get(pair));
2934
2935 // Resolve the exactness method
2936 Symbol ecsym = lookupMethod(tree.pos(),
2937 exactnessFunction,
2938 syms.exactConversionsSupportType,
2939 List.of(pair.from.type));
2940
2941 // Generate the method call ExactnessChecks.<exactness method>(<argument>);
2942 JCFieldAccess select = make.Select(
2943 make.QualIdent(syms.exactConversionsSupportType.tsym),
2944 exactnessFunction);
2945 select.sym = ecsym;
2946 select.setType(syms.booleanType);
2947
2948 JCExpression exactnessCheck = make.Apply(List.nil(),
2949 select,
2950 List.of(argument));
2951 exactnessCheck.setType(syms.booleanType);
2952 return exactnessCheck;
2953 }
2954
2955 public void visitNewClass(JCNewClass tree) {
2956 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
2957
2958 // Box arguments, if necessary
2959 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0;
2960 List<Type> argTypes = tree.constructor.type.getParameterTypes();
2961 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType);
2962 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement);
2963 tree.varargsElement = null;
2964
2965 // If created class is local, add free variables after
2966 // explicit constructor arguments.
2967 if (c.isDirectlyOrIndirectlyLocal() && !c.isStatic()) {
2968 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
2969 }
2970
2971 // If an access constructor is used, append null as a last argument.
2972 Symbol constructor = accessConstructor(tree.pos(), tree.constructor);
2973 if (constructor != tree.constructor) {
2974 tree.args = tree.args.append(makeNull());
2975 tree.constructor = constructor;
2976 }
2977
2978 // If created class has an outer instance, and new is qualified, pass
2979 // qualifier as first argument. If new is not qualified, pass the
2980 // correct outer instance as first argument.
2981 if (c.hasOuterInstance()) {
2982 JCExpression thisArg;
2983 if (tree.encl != null) {
2984 thisArg = attr.makeNullCheck(translate(tree.encl));
2985 thisArg.type = tree.encl.type;
2986 } else if (c.isDirectlyOrIndirectlyLocal()) {
2987 // local class
2988 thisArg = makeThis(tree.pos(), c.innermostAccessibleEnclosingClass());
2989 } else {
2990 // nested class
2991 thisArg = makeOwnerThis(tree.pos(), c, false);
2992 }
2993 tree.args = tree.args.prepend(thisArg);
2994 }
2995 tree.encl = null;
2996
2997 // If we have an anonymous class, create its flat version, rather
2998 // than the class or interface following new.
2999 if (tree.def != null) {
3000 translate(tree.def);
3001
3002 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym));
3003 tree.def = null;
3004 } else {
3005 tree.clazz = access(c, tree.clazz, enclOp, false);
3006 }
3007 result = tree;
3008 }
3009
3010 // Simplify conditionals with known constant controlling expressions.
3011 // This allows us to avoid generating supporting declarations for
3012 // the dead code, which will not be eliminated during code generation.
3013 // Note that Flow.isFalse and Flow.isTrue only return true
3014 // for constant expressions in the sense of JLS 15.27, which
3015 // are guaranteed to have no side-effects. More aggressive
3016 // constant propagation would require that we take care to
3017 // preserve possible side-effects in the condition expression.
3018
3019 // One common case is equality expressions involving a constant and null.
3020 // Since null is not a constant expression (because null cannot be
3021 // represented in the constant pool), equality checks involving null are
3022 // not captured by Flow.isTrue/isFalse.
3023 // Equality checks involving a constant and null, e.g.
3024 // "" == null
3025 // are safe to simplify as no side-effects can occur.
3026
3027 private boolean isTrue(JCTree exp) {
3028 if (exp.type.isTrue())
3029 return true;
3030 Boolean b = expValue(exp);
3031 return b == null ? false : b;
3032 }
3033 private boolean isFalse(JCTree exp) {
3034 if (exp.type.isFalse())
3035 return true;
3036 Boolean b = expValue(exp);
3037 return b == null ? false : !b;
3038 }
3039 /* look for (in)equality relations involving null.
3040 * return true - if expression is always true
3041 * false - if expression is always false
3042 * null - if expression cannot be eliminated
3043 */
3044 private Boolean expValue(JCTree exp) {
3045 while (exp.hasTag(PARENS))
3046 exp = ((JCParens)exp).expr;
3047
3048 boolean eq;
3049 switch (exp.getTag()) {
3050 case EQ: eq = true; break;
3051 case NE: eq = false; break;
3052 default:
3053 return null;
3054 }
3055
3056 // we have a JCBinary(EQ|NE)
3057 // check if we have two literals (constants or null)
3058 JCBinary b = (JCBinary)exp;
3059 if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs);
3060 if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs);
3061 return null;
3062 }
3063 private Boolean expValueIsNull(boolean eq, JCTree t) {
3064 if (t.type.hasTag(BOT)) return Boolean.valueOf(eq);
3065 if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq);
3066 return null;
3067 }
3068
3069 /** Visitor method for conditional expressions.
3070 */
3071 @Override
3072 public void visitConditional(JCConditional tree) {
3073 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
3074 if (isTrue(cond) && noClassDefIn(tree.falsepart)) {
3075 result = convert(translate(tree.truepart, tree.type), tree.type);
3076 addPrunedInfo(cond);
3077 } else if (isFalse(cond) && noClassDefIn(tree.truepart)) {
3078 result = convert(translate(tree.falsepart, tree.type), tree.type);
3079 addPrunedInfo(cond);
3080 } else {
3081 // Condition is not a compile-time constant.
3082 tree.truepart = translate(tree.truepart, tree.type);
3083 tree.falsepart = translate(tree.falsepart, tree.type);
3084 result = tree;
3085 }
3086 }
3087 //where
3088 private JCExpression convert(JCExpression tree, Type pt) {
3089 if (tree.type == pt || tree.type.hasTag(BOT))
3090 return tree;
3091 JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree);
3092 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt)
3093 : pt;
3094 return result;
3095 }
3096
3097 /** Visitor method for if statements.
3098 */
3099 public void visitIf(JCIf tree) {
3100 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
3101 if (isTrue(cond) && noClassDefIn(tree.elsepart)) {
3102 result = translate(tree.thenpart);
3103 addPrunedInfo(cond);
3104 } else if (isFalse(cond) && noClassDefIn(tree.thenpart)) {
3105 if (tree.elsepart != null) {
3106 result = translate(tree.elsepart);
3107 } else {
3108 result = make.Skip();
3109 }
3110 addPrunedInfo(cond);
3111 } else {
3112 // Condition is not a compile-time constant.
3113 tree.thenpart = translate(tree.thenpart);
3114 tree.elsepart = translate(tree.elsepart);
3115 result = tree;
3116 }
3117 }
3118
3119 /** Visitor method for assert statements. Translate them away.
3120 */
3121 public void visitAssert(JCAssert tree) {
3122 tree.cond = translate(tree.cond, syms.booleanType);
3123 if (!tree.cond.type.isTrue()) {
3124 JCExpression cond = assertFlagTest(tree.pos());
3125 List<JCExpression> exnArgs = (tree.detail == null) ?
3126 List.nil() : List.of(translate(tree.detail));
3127 if (!tree.cond.type.isFalse()) {
3128 cond = makeBinary
3129 (AND,
3130 cond,
3131 makeUnary(NOT, tree.cond));
3132 }
3133 result =
3134 make.If(cond,
3135 make_at(tree).
3136 Throw(makeNewClass(syms.assertionErrorType, exnArgs)),
3137 null);
3138 } else {
3139 result = make.Skip();
3140 }
3141 }
3142
3143 public void visitApply(JCMethodInvocation tree) {
3144 Symbol meth = TreeInfo.symbol(tree.meth);
3145 List<Type> argtypes = meth.type.getParameterTypes();
3146 if (meth.name == names.init && meth.owner == syms.enumSym)
3147 argtypes = argtypes.tail.tail;
3148 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement);
3149 tree.varargsElement = null;
3150 Name methName = TreeInfo.name(tree.meth);
3151 if (meth.name==names.init) {
3152 // We are seeing a this(...) or super(...) constructor call.
3153 // If an access constructor is used, append null as a last argument.
3154 Symbol constructor = accessConstructor(tree.pos(), meth);
3155 if (constructor != meth) {
3156 tree.args = tree.args.append(makeNull());
3157 TreeInfo.setSymbol(tree.meth, constructor);
3158 }
3159
3160 // If we are calling a constructor of a local class, add
3161 // free variables after explicit constructor arguments.
3162 ClassSymbol c = (ClassSymbol)constructor.owner;
3163 if (c.isDirectlyOrIndirectlyLocal() && !c.isStatic()) {
3164 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
3165 }
3166
3167 // If we are calling a constructor of an enum class, pass
3168 // along the name and ordinal arguments
3169 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) {
3170 List<JCVariableDecl> params = currentMethodDef.params;
3171 if (currentMethodSym.owner.hasOuterInstance())
3172 params = params.tail; // drop this$n
3173 tree.args = tree.args
3174 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal
3175 .prepend(make.Ident(params.head.sym)); // name
3176 }
3177
3178 // If we are calling a constructor of a class with an outer
3179 // instance, and the call
3180 // is qualified, pass qualifier as first argument in front of
3181 // the explicit constructor arguments. If the call
3182 // is not qualified, pass the correct outer instance as
3183 // first argument. If we are a static class, there is no
3184 // such outer instance, so generate an error.
3185 if (c.hasOuterInstance()) {
3186 JCExpression thisArg;
3187 if (tree.meth.hasTag(SELECT)) {
3188 thisArg = attr.
3189 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected));
3190 tree.meth = make.Ident(constructor);
3191 ((JCIdent) tree.meth).name = methName;
3192 } else if (c.isDirectlyOrIndirectlyLocal() || methName == names._this){
3193 // local class or this() call
3194 thisArg = makeThis(tree.meth.pos(), c.innermostAccessibleEnclosingClass());
3195 } else if (currentClass.isStatic()) {
3196 // super() call from static nested class - invalid
3197 log.error(tree.pos(),
3198 Errors.NoEnclInstanceOfTypeInScope(c.type.getEnclosingType().tsym));
3199 thisArg = make.Literal(BOT, null).setType(syms.botType);
3200 } else {
3201 // super() call of nested class - never pick 'this'
3202 thisArg = makeOwnerThisN(tree.meth.pos(), c, false);
3203 }
3204 tree.args = tree.args.prepend(thisArg);
3205 }
3206 } else {
3207 // We are seeing a normal method invocation; translate this as usual.
3208 tree.meth = translate(tree.meth);
3209
3210 // If the translated method itself is an Apply tree, we are
3211 // seeing an access method invocation. In this case, append
3212 // the method arguments to the arguments of the access method.
3213 if (tree.meth.hasTag(APPLY)) {
3214 JCMethodInvocation app = (JCMethodInvocation)tree.meth;
3215 app.args = tree.args.prependList(app.args);
3216 result = app;
3217 return;
3218 }
3219 }
3220 if (tree.args.stream().anyMatch(c -> c == null)) {
3221 throw new AssertionError("Whooops before: " + tree);
3222 }
3223 result = tree;
3224 }
3225
3226 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) {
3227 List<JCExpression> args = _args;
3228 if (parameters.isEmpty()) return args;
3229 boolean anyChanges = false;
3230 ListBuffer<JCExpression> result = new ListBuffer<>();
3231 while (parameters.tail.nonEmpty()) {
3232 JCExpression arg = translate(args.head, parameters.head);
3233 anyChanges |= (arg != args.head);
3234 result.append(arg);
3235 args = args.tail;
3236 parameters = parameters.tail;
3237 }
3238 Type parameter = parameters.head;
3239 if (varargsElement != null) {
3240 anyChanges = true;
3241 ListBuffer<JCExpression> elems = new ListBuffer<>();
3242 while (args.nonEmpty()) {
3243 JCExpression arg = translate(args.head, varargsElement);
3244 elems.append(arg);
3245 args = args.tail;
3246 }
3247 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement),
3248 List.nil(),
3249 elems.toList());
3250 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass);
3251 result.append(boxedArgs);
3252 } else {
3253 if (args.length() != 1) throw new AssertionError(args);
3254 JCExpression arg = translate(args.head, parameter);
3255 anyChanges |= (arg != args.head);
3256 result.append(arg);
3257 if (!anyChanges) return _args;
3258 }
3259 return result.toList();
3260 }
3261
3262 /** Expand a boxing or unboxing conversion if needed. */
3263 @SuppressWarnings("unchecked") // XXX unchecked
3264 <T extends JCExpression> T boxIfNeeded(T tree, Type type) {
3265 Assert.check(!type.hasTag(VOID));
3266 if (type.hasTag(NONE))
3267 return tree;
3268 boolean havePrimitive = tree.type.isPrimitive();
3269 if (havePrimitive == type.isPrimitive())
3270 return tree;
3271 if (havePrimitive) {
3272 Type unboxedTarget = types.unboxedType(type);
3273 if (!unboxedTarget.hasTag(NONE)) {
3274 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89;
3275 tree.type = unboxedTarget.constType(tree.type.constValue());
3276 return (T)boxPrimitive(tree, types.erasure(type));
3277 } else {
3278 tree = (T)boxPrimitive(tree);
3279 }
3280 } else {
3281 tree = (T)unbox(tree, type);
3282 }
3283 return tree;
3284 }
3285
3286 /** Box up a single primitive expression. */
3287 JCExpression boxPrimitive(JCExpression tree) {
3288 return boxPrimitive(tree, types.boxedClass(tree.type).type);
3289 }
3290
3291 /** Box up a single primitive expression. */
3292 JCExpression boxPrimitive(JCExpression tree, Type box) {
3293 make_at(tree.pos());
3294 Symbol valueOfSym = lookupMethod(tree.pos(),
3295 names.valueOf,
3296 box,
3297 List.<Type>nil()
3298 .prepend(tree.type));
3299 return make.App(make.QualIdent(valueOfSym), List.of(tree));
3300 }
3301
3302 /** Unbox an object to a primitive value. */
3303 JCExpression unbox(JCExpression tree, Type primitive) {
3304 Type unboxedType = types.unboxedType(tree.type);
3305 if (unboxedType.hasTag(NONE)) {
3306 unboxedType = primitive;
3307 if (!unboxedType.isPrimitive())
3308 throw new AssertionError(unboxedType);
3309 make_at(tree.pos());
3310 tree = make.TypeCast(types.boxedClass(unboxedType).type, tree);
3311 } else {
3312 // There must be a conversion from unboxedType to primitive.
3313 if (!types.isSubtype(unboxedType, primitive))
3314 throw new AssertionError(tree);
3315 }
3316 make_at(tree.pos());
3317 Symbol valueSym = lookupMethod(tree.pos(),
3318 unboxedType.tsym.name.append(names.Value), // x.intValue()
3319 tree.type,
3320 List.nil());
3321 return make.App(make.Select(tree, valueSym));
3322 }
3323
3324 /** Visitor method for parenthesized expressions.
3325 * If the subexpression has changed, omit the parens.
3326 */
3327 public void visitParens(JCParens tree) {
3328 JCTree expr = translate(tree.expr);
3329 result = ((expr == tree.expr) ? tree : expr);
3330 }
3331
3332 public void visitIndexed(JCArrayAccess tree) {
3333 tree.indexed = translate(tree.indexed);
3334 tree.index = translate(tree.index, syms.intType);
3335 result = tree;
3336 }
3337
3338 public void visitAssign(JCAssign tree) {
3339 tree.lhs = translate(tree.lhs, tree);
3340 tree.rhs = translate(tree.rhs, tree.lhs.type);
3341
3342 // If translated left hand side is an Apply, we are
3343 // seeing an access method invocation. In this case, append
3344 // right hand side as last argument of the access method.
3345 if (tree.lhs.hasTag(APPLY)) {
3346 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3347 app.args = List.of(tree.rhs).prependList(app.args);
3348 result = app;
3349 } else {
3350 result = tree;
3351 }
3352 }
3353
3354 public void visitAssignop(final JCAssignOp tree) {
3355 final boolean boxingReq = !tree.lhs.type.isPrimitive() &&
3356 tree.operator.type.getReturnType().isPrimitive();
3357
3358 AssignopDependencyScanner depScanner = new AssignopDependencyScanner(tree);
3359 depScanner.scan(tree.rhs);
3360
3361 if (boxingReq || depScanner.dependencyFound) {
3362 // boxing required; need to rewrite as x = (unbox typeof x)(x op y);
3363 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y)
3364 // (but without recomputing x)
3365 JCTree newTree = abstractLval(tree.lhs, lhs -> {
3366 Tag newTag = tree.getTag().noAssignOp();
3367 // Erasure (TransTypes) can change the type of
3368 // tree.lhs. However, we can still get the
3369 // unerased type of tree.lhs as it is stored
3370 // in tree.type in Attr.
3371 OperatorSymbol newOperator = operators.resolveBinary(tree,
3372 newTag,
3373 tree.type,
3374 tree.rhs.type);
3375 //Need to use the "lhs" at two places, once on the future left hand side
3376 //and once in the future binary operator. But further processing may change
3377 //the components of the tree in place (see visitSelect for e.g. <Class>.super.<ident>),
3378 //so cloning the tree to avoid interference between the uses:
3379 JCExpression expr = (JCExpression) lhs.clone();
3380 if (expr.type != tree.type)
3381 expr = make.TypeCast(tree.type, expr);
3382 JCBinary opResult = make.Binary(newTag, expr, tree.rhs);
3383 opResult.operator = newOperator;
3384 opResult.type = newOperator.type.getReturnType();
3385 JCExpression newRhs = boxingReq ?
3386 make.TypeCast(types.unboxedType(tree.type), opResult) :
3387 opResult;
3388 return make.Assign(lhs, newRhs).setType(tree.type);
3389 });
3390 result = translate(newTree);
3391 return;
3392 }
3393 tree.lhs = translate(tree.lhs, tree);
3394 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
3395
3396 // If translated left hand side is an Apply, we are
3397 // seeing an access method invocation. In this case, append
3398 // right hand side as last argument of the access method.
3399 if (tree.lhs.hasTag(APPLY)) {
3400 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3401 // if operation is a += on strings,
3402 // make sure to convert argument to string
3403 JCExpression rhs = tree.operator.opcode == string_add
3404 ? makeString(tree.rhs)
3405 : tree.rhs;
3406 app.args = List.of(rhs).prependList(app.args);
3407 result = app;
3408 } else {
3409 result = tree;
3410 }
3411 }
3412
3413 class AssignopDependencyScanner extends TreeScanner {
3414
3415 Symbol sym;
3416 boolean dependencyFound = false;
3417
3418 AssignopDependencyScanner(JCAssignOp tree) {
3419 this.sym = TreeInfo.symbol(tree.lhs);
3420 }
3421
3422 @Override
3423 public void scan(JCTree tree) {
3424 if (tree != null && sym != null) {
3425 tree.accept(this);
3426 }
3427 }
3428
3429 @Override
3430 public void visitAssignop(JCAssignOp tree) {
3431 if (TreeInfo.symbol(tree.lhs) == sym) {
3432 dependencyFound = true;
3433 return;
3434 }
3435 super.visitAssignop(tree);
3436 }
3437
3438 @Override
3439 public void visitUnary(JCUnary tree) {
3440 if (TreeInfo.symbol(tree.arg) == sym) {
3441 dependencyFound = true;
3442 return;
3443 }
3444 super.visitUnary(tree);
3445 }
3446 }
3447
3448 /** Lower a tree of the form e++ or e-- where e is an object type */
3449 JCExpression lowerBoxedPostop(final JCUnary tree) {
3450 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2
3451 // or
3452 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2
3453 // where OP is += or -=
3454 final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST);
3455 return abstractLval(tree.arg, tmp1 -> abstractRval(tmp1, tree.arg.type, tmp2 -> {
3456 Tag opcode = (tree.hasTag(POSTINC))
3457 ? PLUS_ASG : MINUS_ASG;
3458 //"tmp1" and "tmp2" may refer to the same instance
3459 //(for e.g. <Class>.super.<ident>). But further processing may
3460 //change the components of the tree in place (see visitSelect),
3461 //so cloning the tree to avoid interference between the two uses:
3462 JCExpression lhs = (JCExpression)tmp1.clone();
3463 lhs = cast
3464 ? make.TypeCast(tree.arg.type, lhs)
3465 : lhs;
3466 JCExpression update = makeAssignop(opcode,
3467 lhs,
3468 make.Literal(1));
3469 return makeComma(update, tmp2);
3470 }));
3471 }
3472
3473 public void visitUnary(JCUnary tree) {
3474 boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp();
3475 if (isUpdateOperator && !tree.arg.type.isPrimitive()) {
3476 switch(tree.getTag()) {
3477 case PREINC: // ++ e
3478 // translate to e += 1
3479 case PREDEC: // -- e
3480 // translate to e -= 1
3481 {
3482 JCTree.Tag opcode = (tree.hasTag(PREINC))
3483 ? PLUS_ASG : MINUS_ASG;
3484 JCAssignOp newTree = makeAssignop(opcode,
3485 tree.arg,
3486 make.Literal(1));
3487 result = translate(newTree, tree.type);
3488 return;
3489 }
3490 case POSTINC: // e ++
3491 case POSTDEC: // e --
3492 {
3493 result = translate(lowerBoxedPostop(tree), tree.type);
3494 return;
3495 }
3496 }
3497 throw new AssertionError(tree);
3498 }
3499
3500 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type);
3501
3502 if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) {
3503 tree.type = cfolder.fold1(bool_not, tree.arg.type);
3504 }
3505
3506 // If translated left hand side is an Apply, we are
3507 // seeing an access method invocation. In this case, return
3508 // that access method invocation as result.
3509 if (isUpdateOperator && tree.arg.hasTag(APPLY)) {
3510 result = tree.arg;
3511 } else {
3512 result = tree;
3513 }
3514 }
3515
3516 public void visitBinary(JCBinary tree) {
3517 List<Type> formals = tree.operator.type.getParameterTypes();
3518 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head);
3519 switch (tree.getTag()) {
3520 case OR:
3521 if (isTrue(lhs)) {
3522 result = lhs;
3523 return;
3524 }
3525 if (isFalse(lhs)) {
3526 result = translate(tree.rhs, formals.tail.head);
3527 return;
3528 }
3529 break;
3530 case AND:
3531 if (isFalse(lhs)) {
3532 result = lhs;
3533 return;
3534 }
3535 if (isTrue(lhs)) {
3536 result = translate(tree.rhs, formals.tail.head);
3537 return;
3538 }
3539 break;
3540 }
3541 tree.rhs = translate(tree.rhs, formals.tail.head);
3542 result = tree;
3543 }
3544
3545 public void visitIdent(JCIdent tree) {
3546 result = access(tree.sym, tree, enclOp, false);
3547 }
3548
3549 /** Translate away the foreach loop. */
3550 public void visitForeachLoop(JCEnhancedForLoop tree) {
3551 if (types.elemtype(tree.expr.type) == null)
3552 visitIterableForeachLoop(tree);
3553 else
3554 visitArrayForeachLoop(tree);
3555 }
3556 // where
3557 /**
3558 * A statement of the form
3559 *
3560 * <pre>
3561 * for ( T v : arrayexpr ) stmt;
3562 * </pre>
3563 *
3564 * (where arrayexpr is of an array type) gets translated to
3565 *
3566 * <pre>{@code
3567 * for ( { arraytype #arr = arrayexpr;
3568 * int #len = array.length;
3569 * int #i = 0; };
3570 * #i < #len; i$++ ) {
3571 * T v = arr$[#i];
3572 * stmt;
3573 * }
3574 * }</pre>
3575 *
3576 * where #arr, #len, and #i are freshly named synthetic local variables.
3577 */
3578 private void visitArrayForeachLoop(JCEnhancedForLoop tree) {
3579 make_at(tree.expr.pos());
3580 VarSymbol arraycache = new VarSymbol(SYNTHETIC,
3581 names.fromString("arr" + target.syntheticNameChar()),
3582 tree.expr.type,
3583 currentMethodSym);
3584 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr);
3585 VarSymbol lencache = new VarSymbol(SYNTHETIC,
3586 names.fromString("len" + target.syntheticNameChar()),
3587 syms.intType,
3588 currentMethodSym);
3589 JCStatement lencachedef = make.
3590 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar));
3591 VarSymbol index = new VarSymbol(SYNTHETIC,
3592 names.fromString("i" + target.syntheticNameChar()),
3593 syms.intType,
3594 currentMethodSym);
3595
3596 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0));
3597 indexdef.init.type = indexdef.type = syms.intType.constType(0);
3598
3599 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef);
3600 JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache));
3601
3602 JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index)));
3603
3604 Type elemtype = types.elemtype(tree.expr.type);
3605 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache),
3606 make.Ident(index)).setType(elemtype);
3607 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods,
3608 tree.var.name,
3609 tree.var.vartype,
3610 loopvarinit).setType(tree.var.type);
3611 loopvardef.sym = tree.var.sym;
3612 JCBlock body = make.
3613 Block(0, List.of(loopvardef, tree.body));
3614
3615 result = translate(make.
3616 ForLoop(loopinit,
3617 cond,
3618 List.of(step),
3619 body));
3620 patchTargets(body, tree, result);
3621 }
3622 /** Patch up break and continue targets. */
3623 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) {
3624 class Patcher extends TreeScanner {
3625 public void visitBreak(JCBreak tree) {
3626 if (tree.target == src)
3627 tree.target = dest;
3628 }
3629 public void visitYield(JCYield tree) {
3630 if (tree.target == src)
3631 tree.target = dest;
3632 scan(tree.value);
3633 }
3634 public void visitContinue(JCContinue tree) {
3635 if (tree.target == src)
3636 tree.target = dest;
3637 }
3638 public void visitClassDef(JCClassDecl tree) {}
3639 }
3640 new Patcher().scan(body);
3641 }
3642 /**
3643 * A statement of the form
3644 *
3645 * <pre>
3646 * for ( T v : coll ) stmt ;
3647 * </pre>
3648 *
3649 * (where coll implements {@code Iterable<? extends T>}) gets translated to
3650 *
3651 * <pre>{@code
3652 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) {
3653 * T v = (T) #i.next();
3654 * stmt;
3655 * }
3656 * }</pre>
3657 *
3658 * where #i is a freshly named synthetic local variable.
3659 */
3660 private void visitIterableForeachLoop(JCEnhancedForLoop tree) {
3661 make_at(tree.expr.pos());
3662 Type iteratorTarget = syms.objectType;
3663 Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type),
3664 syms.iterableType.tsym);
3665 if (iterableType.getTypeArguments().nonEmpty())
3666 iteratorTarget = types.erasure(iterableType.getTypeArguments().head);
3667 tree.expr.type = types.erasure(types.skipTypeVars(tree.expr.type, false));
3668 tree.expr = transTypes.coerce(attrEnv, tree.expr, types.erasure(iterableType));
3669 Symbol iterator = lookupMethod(tree.expr.pos(),
3670 names.iterator,
3671 tree.expr.type,
3672 List.nil());
3673 Assert.check(types.isSameType(types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)), types.erasure(syms.iteratorType)));
3674 VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()),
3675 types.erasure(syms.iteratorType),
3676 currentMethodSym);
3677
3678 JCStatement init = make.
3679 VarDef(itvar, make.App(make.Select(tree.expr, iterator)
3680 .setType(types.erasure(iterator.type))));
3681
3682 Symbol hasNext = lookupMethod(tree.expr.pos(),
3683 names.hasNext,
3684 itvar.type,
3685 List.nil());
3686 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext));
3687 Symbol next = lookupMethod(tree.expr.pos(),
3688 names.next,
3689 itvar.type,
3690 List.nil());
3691 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next));
3692 if (tree.var.type.isPrimitive())
3693 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit);
3694 else
3695 vardefinit = make.TypeCast(tree.var.type, vardefinit);
3696 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods,
3697 tree.var.name,
3698 tree.var.vartype,
3699 vardefinit).setType(tree.var.type);
3700 indexDef.sym = tree.var.sym;
3701 JCBlock body = make.Block(0, List.of(indexDef, tree.body));
3702 body.bracePos = TreeInfo.endPos(tree.body);
3703 result = translate(make.
3704 ForLoop(List.of(init),
3705 cond,
3706 List.nil(),
3707 body));
3708 patchTargets(body, tree, result);
3709 }
3710
3711 public void visitVarDef(JCVariableDecl tree) {
3712 MethodSymbol oldMethodSym = currentMethodSym;
3713 int prevVariableIndex = variableIndex;
3714 tree.mods = translate(tree.mods);
3715 tree.vartype = translate(tree.vartype);
3716 if (currentMethodSym == null) {
3717 // A class or instance field initializer.
3718 currentMethodSym =
3719 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK,
3720 names.empty, null,
3721 currentClass);
3722 }
3723 try {
3724 if (tree.init != null) tree.init = translate(tree.init, tree.type);
3725 result = tree;
3726 } finally {
3727 currentMethodSym = oldMethodSym;
3728 variableIndex = prevVariableIndex;
3729 }
3730 }
3731
3732 public void visitBlock(JCBlock tree) {
3733 MethodSymbol oldMethodSym = currentMethodSym;
3734 if (currentMethodSym == null) {
3735 // Block is a static or instance initializer.
3736 currentMethodSym =
3737 new MethodSymbol(tree.flags | BLOCK,
3738 names.empty, null,
3739 currentClass);
3740 }
3741 int prevVariableIndex = variableIndex;
3742 try {
3743 variableIndex = 0;
3744 super.visitBlock(tree);
3745 } finally {
3746 currentMethodSym = oldMethodSym;
3747 variableIndex = prevVariableIndex;
3748 }
3749 }
3750
3751 public void visitDoLoop(JCDoWhileLoop tree) {
3752 tree.body = translate(tree.body);
3753 tree.cond = translate(tree.cond, syms.booleanType);
3754 result = tree;
3755 }
3756
3757 public void visitWhileLoop(JCWhileLoop tree) {
3758 tree.cond = translate(tree.cond, syms.booleanType);
3759 tree.body = translate(tree.body);
3760 result = tree;
3761 }
3762
3763 public void visitForLoop(JCForLoop tree) {
3764 tree.init = translate(tree.init);
3765 if (tree.cond != null)
3766 tree.cond = translate(tree.cond, syms.booleanType);
3767 tree.step = translate(tree.step);
3768 tree.body = translate(tree.body);
3769 result = tree;
3770 }
3771
3772 public void visitReturn(JCReturn tree) {
3773 if (tree.expr != null)
3774 tree.expr = translate(tree.expr,
3775 currentRestype);
3776 result = tree;
3777 }
3778
3779 @Override
3780 public void visitLambda(JCLambda tree) {
3781 Type prevRestype = currentRestype;
3782 try {
3783 currentRestype = types.erasure(tree.getDescriptorType(types)).getReturnType();
3784 // represent void results as NO_TYPE, to avoid unnecessary boxing in boxIfNeeded
3785 if (currentRestype.hasTag(VOID))
3786 currentRestype = Type.noType;
3787 tree.body = tree.getBodyKind() == BodyKind.EXPRESSION ?
3788 translate((JCExpression) tree.body, currentRestype) :
3789 translate(tree.body);
3790 } finally {
3791 currentRestype = prevRestype;
3792 }
3793 result = tree;
3794 }
3795
3796 public void visitSwitch(JCSwitch tree) {
3797 List<JCCase> cases = tree.patternSwitch ? addDefaultIfNeeded(tree.patternSwitch,
3798 tree.wasEnumSelector,
3799 tree.cases)
3800 : tree.cases;
3801 handleSwitch(tree, tree.selector, cases);
3802 }
3803
3804 @Override
3805 public void visitSwitchExpression(JCSwitchExpression tree) {
3806 List<JCCase> cases = addDefaultIfNeeded(tree.patternSwitch, tree.wasEnumSelector, tree.cases);
3807 handleSwitch(tree, tree.selector, cases);
3808 }
3809
3810 private List<JCCase> addDefaultIfNeeded(boolean patternSwitch, boolean wasEnumSelector,
3811 List<JCCase> cases) {
3812 if (cases.stream().flatMap(c -> c.labels.stream()).noneMatch(p -> p.hasTag(Tag.DEFAULTCASELABEL))) {
3813 boolean matchException = useMatchException;
3814 matchException |= patternSwitch && !wasEnumSelector;
3815 Type exception = matchException ? syms.matchExceptionType
3816 : syms.incompatibleClassChangeErrorType;
3817 List<JCExpression> params = matchException ? List.of(makeNull(), makeNull())
3818 : List.nil();
3819 JCThrow thr = make.Throw(makeNewClass(exception, params));
3820 JCCase c = make.Case(JCCase.STATEMENT, List.of(make.DefaultCaseLabel()), null, List.of(thr), null);
3821 cases = cases.prepend(c);
3822 }
3823
3824 return cases;
3825 }
3826
3827 private void handleSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
3828 //expand multiple label cases:
3829 ListBuffer<JCCase> convertedCases = new ListBuffer<>();
3830
3831 for (JCCase c : cases) {
3832 switch (c.labels.size()) {
3833 case 0: //default
3834 case 1: //single label
3835 convertedCases.append(c);
3836 break;
3837 default: //multiple labels, expand:
3838 //case C1, C2, C3: ...
3839 //=>
3840 //case C1:
3841 //case C2:
3842 //case C3: ...
3843 List<JCCaseLabel> patterns = c.labels;
3844 while (patterns.tail.nonEmpty()) {
3845 convertedCases.append(make_at(c.pos()).Case(JCCase.STATEMENT,
3846 List.of(patterns.head),
3847 null,
3848 List.nil(),
3849 null));
3850 patterns = patterns.tail;
3851 }
3852 c.labels = patterns;
3853 convertedCases.append(c);
3854 break;
3855 }
3856 }
3857
3858 for (JCCase c : convertedCases) {
3859 if (c.caseKind == JCCase.RULE && c.completesNormally) {
3860 JCBreak b = make.at(TreeInfo.endPos(c.stats.last())).Break(null);
3861 b.target = tree;
3862 c.stats = c.stats.append(b);
3863 }
3864 }
3865
3866 cases = convertedCases.toList();
3867
3868 Type selsuper = types.supertype(selector.type);
3869 boolean enumSwitch = selsuper != null &&
3870 (selector.type.tsym.flags() & ENUM) != 0;
3871 boolean stringSwitch = selsuper != null &&
3872 types.isSameType(selector.type, syms.stringType);
3873 boolean boxedSwitch = !enumSwitch && !stringSwitch && !selector.type.isPrimitive();
3874 selector = translate(selector, selector.type);
3875 cases = translateCases(cases);
3876 if (tree.hasTag(SWITCH)) {
3877 ((JCSwitch) tree).selector = selector;
3878 ((JCSwitch) tree).cases = cases;
3879 } else if (tree.hasTag(SWITCH_EXPRESSION)) {
3880 ((JCSwitchExpression) tree).selector = selector;
3881 ((JCSwitchExpression) tree).cases = cases;
3882 } else {
3883 Assert.error();
3884 }
3885 if (enumSwitch) {
3886 result = visitEnumSwitch(tree, selector, cases);
3887 } else if (stringSwitch) {
3888 result = visitStringSwitch(tree, selector, cases);
3889 } else if (boxedSwitch) {
3890 //An switch over boxed primitive. Pattern matching switches are already translated
3891 //by TransPatterns, so all non-primitive types are only boxed primitives:
3892 result = visitBoxedPrimitiveSwitch(tree, selector, cases);
3893 } else {
3894 result = tree;
3895 }
3896 }
3897
3898 public JCTree visitEnumSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
3899 TypeSymbol enumSym = selector.type.tsym;
3900 EnumMapping map = mapForEnum(tree.pos(), enumSym);
3901 make_at(tree.pos());
3902 Symbol ordinalMethod = lookupMethod(tree.pos(),
3903 names.ordinal,
3904 selector.type,
3905 List.nil());
3906 JCExpression newSelector;
3907
3908 if (cases.stream().anyMatch(c -> TreeInfo.isNullCaseLabel(c.labels.head))) {
3909 //for enum switches with case null, do:
3910 //switch ($selector != null ? $mapVar[$selector.ordinal()] : -1) {...}
3911 //replacing case null with case -1:
3912 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
3913 names.fromString("s" + variableIndex++ + this.target.syntheticNameChar()),
3914 selector.type,
3915 currentMethodSym);
3916 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type);
3917 newSelector = map.switchValue(
3918 make.App(make.Select(make.Ident(dollar_s),
3919 ordinalMethod)));
3920 newSelector =
3921 make.LetExpr(List.of(var),
3922 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()),
3923 newSelector,
3924 makeLit(syms.intType, -1))
3925 .setType(newSelector.type))
3926 .setType(newSelector.type);
3927 } else {
3928 newSelector = map.switchValue(
3929 make.App(make.Select(selector,
3930 ordinalMethod)));
3931 }
3932 ListBuffer<JCCase> newCases = new ListBuffer<>();
3933 for (JCCase c : cases) {
3934 if (c.labels.head.hasTag(CONSTANTCASELABEL)) {
3935 JCExpression pat;
3936 if (TreeInfo.isNullCaseLabel(c.labels.head)) {
3937 pat = makeLit(syms.intType, -1);
3938 } else {
3939 VarSymbol label = (VarSymbol)TreeInfo.symbol(((JCConstantCaseLabel) c.labels.head).expr);
3940 pat = map.caseValue(label);
3941 }
3942 newCases.append(make.Case(JCCase.STATEMENT, List.of(make.ConstantCaseLabel(pat)), null, c.stats, null));
3943 } else {
3944 newCases.append(c);
3945 }
3946 }
3947 JCTree enumSwitch;
3948 if (tree.hasTag(SWITCH)) {
3949 enumSwitch = make.Switch(newSelector, newCases.toList());
3950 } else if (tree.hasTag(SWITCH_EXPRESSION)) {
3951 enumSwitch = make.SwitchExpression(newSelector, newCases.toList());
3952 enumSwitch.setType(tree.type);
3953 } else {
3954 Assert.error();
3955 throw new AssertionError();
3956 }
3957 patchTargets(enumSwitch, tree, enumSwitch);
3958 return enumSwitch;
3959 }
3960
3961 public JCTree visitStringSwitch(JCTree tree, JCExpression selector, List<JCCase> caseList) {
3962 int alternatives = caseList.size();
3963
3964 if (alternatives == 0) { // Strange but legal possibility (only legal for switch statement)
3965 return make.at(tree.pos()).Exec(attr.makeNullCheck(selector));
3966 } else {
3967 /*
3968 * The general approach used is to translate a single
3969 * string switch statement into a series of two chained
3970 * switch statements: the first a synthesized statement
3971 * switching on the argument string's hash value and
3972 * computing a string's position in the list of original
3973 * case labels, if any, followed by a second switch on the
3974 * computed integer value. The second switch has the same
3975 * code structure as the original string switch statement
3976 * except that the string case labels are replaced with
3977 * positional integer constants starting at 0.
3978 *
3979 * The first switch statement can be thought of as an
3980 * inlined map from strings to their position in the case
3981 * label list. An alternate implementation would use an
3982 * actual Map for this purpose, as done for enum switches.
3983 *
3984 * With some additional effort, it would be possible to
3985 * use a single switch statement on the hash code of the
3986 * argument, but care would need to be taken to preserve
3987 * the proper control flow in the presence of hash
3988 * collisions and other complications, such as
3989 * fallthroughs. Switch statements with one or two
3990 * alternatives could also be specially translated into
3991 * if-then statements to omit the computation of the hash
3992 * code.
3993 *
3994 * The generated code assumes that the hashing algorithm
3995 * of String is the same in the compilation environment as
3996 * in the environment the code will run in. The string
3997 * hashing algorithm in the SE JDK has been unchanged
3998 * since at least JDK 1.2. Since the algorithm has been
3999 * specified since that release as well, it is very
4000 * unlikely to be changed in the future.
4001 *
4002 * Different hashing algorithms, such as the length of the
4003 * strings or a perfect hashing algorithm over the
4004 * particular set of case labels, could potentially be
4005 * used instead of String.hashCode.
4006 */
4007
4008 ListBuffer<JCStatement> stmtList = new ListBuffer<>();
4009
4010 // Map from String case labels to their original position in
4011 // the list of case labels.
4012 Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f);
4013
4014 // Map of hash codes to the string case labels having that hashCode.
4015 Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f);
4016
4017 int casePosition = 0;
4018 JCCase nullCase = null;
4019 int nullCaseLabel = -1;
4020
4021 for(JCCase oneCase : caseList) {
4022 if (oneCase.labels.head.hasTag(CONSTANTCASELABEL)) {
4023 if (TreeInfo.isNullCaseLabel(oneCase.labels.head)) {
4024 nullCase = oneCase;
4025 nullCaseLabel = casePosition;
4026 } else {
4027 JCExpression expression = ((JCConstantCaseLabel) oneCase.labels.head).expr;
4028 String labelExpr = (String) expression.type.constValue();
4029 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition);
4030 Assert.checkNull(mapping);
4031 int hashCode = labelExpr.hashCode();
4032
4033 Set<String> stringSet = hashToString.get(hashCode);
4034 if (stringSet == null) {
4035 stringSet = new LinkedHashSet<>(1, 1.0f);
4036 stringSet.add(labelExpr);
4037 hashToString.put(hashCode, stringSet);
4038 } else {
4039 boolean added = stringSet.add(labelExpr);
4040 Assert.check(added);
4041 }
4042 }
4043 }
4044 casePosition++;
4045 }
4046
4047 // Synthesize a switch statement that has the effect of
4048 // mapping from a string to the integer position of that
4049 // string in the list of case labels. This is done by
4050 // switching on the hashCode of the string followed by an
4051 // if-then-else chain comparing the input for equality
4052 // with all the case labels having that hash value.
4053
4054 /*
4055 * s$ = top of stack;
4056 * tmp$ = -1;
4057 * switch($s.hashCode()) {
4058 * case caseLabel.hashCode:
4059 * if (s$.equals("caseLabel_1")
4060 * tmp$ = caseLabelToPosition("caseLabel_1");
4061 * else if (s$.equals("caseLabel_2"))
4062 * tmp$ = caseLabelToPosition("caseLabel_2");
4063 * ...
4064 * break;
4065 * ...
4066 * }
4067 */
4068
4069 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
4070 names.fromString("s" + variableIndex++ + target.syntheticNameChar()),
4071 syms.stringType,
4072 currentMethodSym);
4073 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type));
4074
4075 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC,
4076 names.fromString("tmp" + variableIndex++ + target.syntheticNameChar()),
4077 syms.intType,
4078 currentMethodSym);
4079 JCVariableDecl dollar_tmp_def =
4080 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type);
4081 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType;
4082 stmtList.append(dollar_tmp_def);
4083 ListBuffer<JCCase> caseBuffer = new ListBuffer<>();
4084 // hashCode will trigger nullcheck on original switch expression
4085 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s),
4086 names.hashCode,
4087 List.nil()).setType(syms.intType);
4088 JCSwitch switch1 = make.Switch(hashCodeCall,
4089 caseBuffer.toList());
4090 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) {
4091 int hashCode = entry.getKey();
4092 Set<String> stringsWithHashCode = entry.getValue();
4093 Assert.check(stringsWithHashCode.size() >= 1);
4094
4095 JCStatement elsepart = null;
4096 for(String caseLabel : stringsWithHashCode ) {
4097 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s),
4098 names.equals,
4099 List.of(make.Literal(caseLabel)));
4100 elsepart = make.If(stringEqualsCall,
4101 make.Exec(make.Assign(make.Ident(dollar_tmp),
4102 make.Literal(caseLabelToPosition.get(caseLabel))).
4103 setType(dollar_tmp.type)),
4104 elsepart);
4105 }
4106
4107 ListBuffer<JCStatement> lb = new ListBuffer<>();
4108 JCBreak breakStmt = make.Break(null);
4109 breakStmt.target = switch1;
4110 lb.append(elsepart).append(breakStmt);
4111
4112 caseBuffer.append(make.Case(JCCase.STATEMENT,
4113 List.of(make.ConstantCaseLabel(make.Literal(hashCode))),
4114 null,
4115 lb.toList(),
4116 null));
4117 }
4118
4119 switch1.cases = caseBuffer.toList();
4120
4121 if (nullCase != null) {
4122 stmtList.append(make.If(makeBinary(NE, make.Ident(dollar_s), makeNull()), switch1, make.Exec(make.Assign(make.Ident(dollar_tmp),
4123 make.Literal(nullCaseLabel)).
4124 setType(dollar_tmp.type))).setType(syms.intType));
4125 } else {
4126 stmtList.append(switch1);
4127 }
4128
4129 // Make isomorphic switch tree replacing string labels
4130 // with corresponding integer ones from the label to
4131 // position map.
4132
4133 ListBuffer<JCCase> lb = new ListBuffer<>();
4134 for(JCCase oneCase : caseList ) {
4135 boolean isDefault = !oneCase.labels.head.hasTag(CONSTANTCASELABEL);
4136 JCExpression caseExpr;
4137 if (isDefault)
4138 caseExpr = null;
4139 else if (oneCase == nullCase) {
4140 caseExpr = make.Literal(nullCaseLabel);
4141 } else {
4142 JCExpression expression = ((JCConstantCaseLabel) oneCase.labels.head).expr;
4143 String name = (String) TreeInfo.skipParens(expression)
4144 .type.constValue();
4145 caseExpr = make.Literal(caseLabelToPosition.get(name));
4146 }
4147
4148 lb.append(make.Case(JCCase.STATEMENT, caseExpr == null ? List.of(make.DefaultCaseLabel())
4149 : List.of(make.ConstantCaseLabel(caseExpr)),
4150 null,
4151 oneCase.stats, null));
4152 }
4153
4154 if (tree.hasTag(SWITCH)) {
4155 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList());
4156 // Rewire up old unlabeled break statements to the
4157 // replacement switch being created.
4158 patchTargets(switch2, tree, switch2);
4159
4160 stmtList.append(switch2);
4161
4162 JCBlock res = make.Block(0L, stmtList.toList());
4163 res.bracePos = TreeInfo.endPos(tree);
4164 return res;
4165 } else {
4166 JCSwitchExpression switch2 = make.SwitchExpression(make.Ident(dollar_tmp), lb.toList());
4167
4168 // Rewire up old unlabeled break statements to the
4169 // replacement switch being created.
4170 patchTargets(switch2, tree, switch2);
4171
4172 switch2.setType(tree.type);
4173
4174 LetExpr res = make.LetExpr(stmtList.toList(), switch2);
4175
4176 res.needsCond = true;
4177 res.setType(tree.type);
4178
4179 return res;
4180 }
4181 }
4182 }
4183
4184 private JCTree visitBoxedPrimitiveSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
4185 JCExpression newSelector;
4186
4187 if (cases.stream().anyMatch(c -> TreeInfo.isNullCaseLabel(c.labels.head))) {
4188 //a switch over a boxed primitive, with a null case. Pick two constants that are
4189 //not used by any branch in the case (c1 and c2), close to other constants that are
4190 //used in the switch. Then do:
4191 //switch ($selector != null ? $selector != c1 ? $selector : c2 : c1) {...}
4192 //replacing case null with case c1
4193 Set<Integer> constants = new LinkedHashSet<>();
4194 JCCase nullCase = null;
4195
4196 for (JCCase c : cases) {
4197 if (TreeInfo.isNullCaseLabel(c.labels.head)) {
4198 nullCase = c;
4199 } else if (!c.labels.head.hasTag(DEFAULTCASELABEL)) {
4200 constants.add((int) ((JCConstantCaseLabel) c.labels.head).expr.type.constValue());
4201 }
4202 }
4203
4204 Assert.checkNonNull(nullCase);
4205
4206 int nullValue = constants.isEmpty() ? 0 : constants.iterator().next();
4207
4208 while (constants.contains(nullValue)) nullValue++;
4209
4210 constants.add(nullValue);
4211 nullCase.labels.head = make.ConstantCaseLabel(makeLit(syms.intType, nullValue));
4212
4213 int replacementValue = nullValue;
4214
4215 while (constants.contains(replacementValue)) replacementValue++;
4216
4217 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
4218 names.fromString("s" + variableIndex++ + this.target.syntheticNameChar()),
4219 selector.type,
4220 currentMethodSym);
4221 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type);
4222 JCExpression nullValueReplacement =
4223 make.Conditional(makeBinary(NE,
4224 unbox(make.Ident(dollar_s), syms.intType),
4225 makeLit(syms.intType, nullValue)),
4226 unbox(make.Ident(dollar_s), syms.intType),
4227 makeLit(syms.intType, replacementValue))
4228 .setType(syms.intType);
4229 JCExpression nullCheck =
4230 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()),
4231 nullValueReplacement,
4232 makeLit(syms.intType, nullValue))
4233 .setType(syms.intType);
4234 newSelector = make.LetExpr(List.of(var), nullCheck).setType(syms.intType);
4235 } else {
4236 newSelector = unbox(selector, syms.intType);
4237 }
4238
4239 if (tree.hasTag(SWITCH)) {
4240 ((JCSwitch) tree).selector = newSelector;
4241 } else {
4242 ((JCSwitchExpression) tree).selector = newSelector;
4243 }
4244
4245 return tree;
4246 }
4247
4248 @Override
4249 public void visitBreak(JCBreak tree) {
4250 result = tree;
4251 }
4252
4253 @Override
4254 public void visitYield(JCYield tree) {
4255 tree.value = translate(tree.value, tree.target.type);
4256 result = tree;
4257 }
4258
4259 public void visitNewArray(JCNewArray tree) {
4260 tree.elemtype = translate(tree.elemtype);
4261 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail)
4262 if (t.head != null) t.head = translate(t.head, syms.intType);
4263 tree.elems = translate(tree.elems, types.elemtype(tree.type));
4264 result = tree;
4265 }
4266
4267 public void visitSelect(JCFieldAccess tree) {
4268 // need to special case-access of the form C.super.x
4269 // these will always need an access method, unless C
4270 // is a default interface subclassed by the current class.
4271 boolean qualifiedSuperAccess =
4272 tree.selected.hasTag(SELECT) &&
4273 TreeInfo.name(tree.selected) == names._super &&
4274 !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass);
4275 tree.selected = translate(tree.selected);
4276 if (tree.name == names._class && tree.selected.type.isPrimitiveOrVoid()) {
4277 result = classOf(tree.selected);
4278 }
4279 else if (tree.name == names._super &&
4280 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) {
4281 //default super call!! Not a classic qualified super call
4282 TypeSymbol supSym = tree.selected.type.tsym;
4283 Assert.checkNonNull(types.asSuper(currentClass.type, supSym));
4284 result = tree;
4285 }
4286 else if (tree.name == names._this || tree.name == names._super) {
4287 result = makeThis(tree.pos(), tree.selected.type.tsym);
4288 }
4289 else
4290 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess);
4291 }
4292
4293 public void visitLetExpr(LetExpr tree) {
4294 tree.defs = translate(tree.defs);
4295 tree.expr = translate(tree.expr, tree.type);
4296 result = tree;
4297 }
4298
4299 // There ought to be nothing to rewrite here;
4300 // we don't generate code.
4301 public void visitAnnotation(JCAnnotation tree) {
4302 result = tree;
4303 }
4304
4305 @Override
4306 public void visitTry(JCTry tree) {
4307 if (tree.resources.nonEmpty()) {
4308 result = makeTwrTry(tree);
4309 return;
4310 }
4311
4312 boolean hasBody = tree.body.getStatements().nonEmpty();
4313 boolean hasCatchers = tree.catchers.nonEmpty();
4314 boolean hasFinally = tree.finalizer != null &&
4315 tree.finalizer.getStatements().nonEmpty();
4316
4317 if (!hasCatchers && !hasFinally) {
4318 result = translate(tree.body);
4319 return;
4320 }
4321
4322 if (!hasBody) {
4323 if (hasFinally) {
4324 result = translate(tree.finalizer);
4325 } else {
4326 result = translate(tree.body);
4327 }
4328 return;
4329 }
4330
4331 // no optimizations possible
4332 super.visitTry(tree);
4333 }
4334
4335 /* ************************************************************************
4336 * main method
4337 *************************************************************************/
4338
4339 /** Translate a toplevel class and return a list consisting of
4340 * the translated class and translated versions of all inner classes.
4341 * @param env The attribution environment current at the class definition.
4342 * We need this for resolving some additional symbols.
4343 * @param cdef The tree representing the class definition.
4344 */
4345 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) {
4346 ListBuffer<JCTree> translated = null;
4347 try {
4348 attrEnv = env;
4349 this.make = make;
4350 currentClass = null;
4351 currentRestype = null;
4352 currentMethodDef = null;
4353 outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null;
4354 outermostMemberDef = null;
4355 this.translated = new ListBuffer<>();
4356 classdefs = new HashMap<>();
4357 actualSymbols = new HashMap<>();
4358 freevarCache = new HashMap<>();
4359 proxies = new HashMap<>();
4360 twrVars = WriteableScope.create(syms.noSymbol);
4361 outerThisStack = List.nil();
4362 accessNums = new HashMap<>();
4363 accessSyms = new HashMap<>();
4364 accessConstrs = new HashMap<>();
4365 accessConstrTags = List.nil();
4366 accessed = new ListBuffer<>();
4367 translate(cdef, (JCExpression)null);
4368 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail)
4369 makeAccessible(l.head);
4370 for (EnumMapping map : enumSwitchMap.values())
4371 map.translate();
4372 checkConflicts(this.translated.toList());
4373 checkAccessConstructorTags();
4374 translated = this.translated;
4375 } finally {
4376 // note that recursive invocations of this method fail hard
4377 attrEnv = null;
4378 this.make = null;
4379 currentClass = null;
4380 currentRestype = null;
4381 currentMethodDef = null;
4382 outermostClassDef = null;
4383 outermostMemberDef = null;
4384 this.translated = null;
4385 classdefs = null;
4386 actualSymbols = null;
4387 freevarCache = null;
4388 proxies = null;
4389 outerThisStack = null;
4390 accessNums = null;
4391 accessSyms = null;
4392 accessConstrs = null;
4393 accessConstrTags = null;
4394 accessed = null;
4395 enumSwitchMap.clear();
4396 assertionsDisabledClassCache = null;
4397 }
4398 return translated.toList();
4399 }
4400
4401 // needed for the lambda deserialization method, which is expressed as a big switch on strings
4402 public JCMethodDecl translateMethod(Env<AttrContext> env, JCMethodDecl methodDecl, TreeMaker make) {
4403 try {
4404 this.attrEnv = env;
4405 this.make = make;
4406 this.currentClass = methodDecl.sym.enclClass();
4407 proxies = new HashMap<>();
4408 return translate(methodDecl);
4409 } finally {
4410 this.attrEnv = null;
4411 this.make = null;
4412 this.currentClass = null;
4413 // the two fields below are set when visiting the method
4414 this.currentMethodSym = null;
4415 this.currentMethodDef = null;
4416 this.proxies = null;
4417 }
4418 }
4419 }