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 import com.sun.tools.javac.tree.EndPosTable;
52
53 import static com.sun.tools.javac.code.Flags.*;
54 import static com.sun.tools.javac.code.Flags.BLOCK;
55 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
56 import static com.sun.tools.javac.code.TypeTag.*;
57 import static com.sun.tools.javac.code.Kinds.Kind.*;
58 import com.sun.tools.javac.code.Source.Feature;
59 import static com.sun.tools.javac.jvm.ByteCodes.*;
60 import com.sun.tools.javac.tree.JCTree.JCBreak;
61 import com.sun.tools.javac.tree.JCTree.JCCase;
62 import com.sun.tools.javac.tree.JCTree.JCExpression;
63 import com.sun.tools.javac.tree.JCTree.JCExpressionStatement;
64
65 import static com.sun.tools.javac.tree.JCTree.JCOperatorExpression.OperandPos.LEFT;
66 import com.sun.tools.javac.tree.JCTree.JCSwitchExpression;
67
68 import static com.sun.tools.javac.tree.JCTree.Tag.*;
69
70 /** This pass translates away some syntactic sugar: inner classes,
71 * class literals, assertions, foreach loops, etc.
72 *
73 * <p><b>This is NOT part of any supported API.
74 * If you write code that depends on this, you do so at your own risk.
75 * This code and its internal interfaces are subject to change or
76 * deletion without notice.</b>
77 */
78 public class Lower extends TreeTranslator {
79 protected static final Context.Key<Lower> lowerKey = new Context.Key<>();
80
81 public static Lower instance(Context context) {
82 Lower instance = context.get(lowerKey);
83 if (instance == null)
84 instance = new Lower(context);
85 return instance;
86 }
87
88 private final Names names;
89 private final Log log;
90 private final Symtab syms;
91 private final Resolve rs;
92 private final Operators operators;
93 private final Check chk;
94 private final Attr attr;
95 private TreeMaker make;
96 private DiagnosticPosition make_pos;
97 private final ConstFold cfolder;
98 private final Target target;
99 private final TypeEnvs typeEnvs;
100 private final Name dollarAssertionsDisabled;
101 private final Types types;
102 private final TransTypes transTypes;
103 private final boolean debugLower;
104 private final boolean disableProtectedAccessors; // experimental
105 private final PkgInfo pkginfoOpt;
106 private final boolean optimizeOuterThis;
107 private final boolean nullCheckOuterThis;
108 private final boolean useMatchException;
109 private final HashMap<TypePairs, String> typePairToName;
110 private int variableIndex = 0;
111
112 @SuppressWarnings("this-escape")
113 protected Lower(Context context) {
114 context.put(lowerKey, this);
115 names = Names.instance(context);
116 log = Log.instance(context);
117 syms = Symtab.instance(context);
118 rs = Resolve.instance(context);
119 operators = Operators.instance(context);
120 chk = Check.instance(context);
121 attr = Attr.instance(context);
122 make = TreeMaker.instance(context);
123 cfolder = ConstFold.instance(context);
124 target = Target.instance(context);
125 typeEnvs = TypeEnvs.instance(context);
126 dollarAssertionsDisabled = names.
127 fromString(target.syntheticNameChar() + "assertionsDisabled");
128
129 types = Types.instance(context);
130 transTypes = TransTypes.instance(context);
131 Options options = Options.instance(context);
132 debugLower = options.isSet("debuglower");
133 pkginfoOpt = PkgInfo.get(options);
134 optimizeOuterThis =
135 target.optimizeOuterThis() ||
136 options.getBoolean("optimizeOuterThis", false);
137 nullCheckOuterThis = options.getBoolean("nullCheckOuterThis",
138 target.nullCheckOuterThisByDefault());
139 disableProtectedAccessors = options.isSet("disableProtectedAccessors");
140 Source source = Source.instance(context);
141 Preview preview = Preview.instance(context);
142 useMatchException = Feature.PATTERN_SWITCH.allowedInSource(source) &&
143 (preview.isEnabled() || !preview.isPreview(Feature.PATTERN_SWITCH));
144 typePairToName = TypePairs.initialize(syms);
145 }
146
147 /** The currently enclosing class.
148 */
149 ClassSymbol currentClass;
150
151 /** A queue of all translated classes.
152 */
153 ListBuffer<JCTree> translated;
154
155 /** Environment for symbol lookup, set by translateTopLevelClass.
156 */
157 Env<AttrContext> attrEnv;
158
159 /** A hash table mapping syntax trees to their ending source positions.
160 */
161 EndPosTable endPosTable;
162
163 /* ************************************************************************
164 * Global mappings
165 *************************************************************************/
166
167 /** A hash table mapping local classes to their definitions.
168 */
169 Map<ClassSymbol, JCClassDecl> classdefs;
170
171 /** A hash table mapping local classes to a list of pruned trees.
172 */
173 public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<>();
174
175 /** A hash table mapping virtual accessed symbols in outer subclasses
176 * to the actually referred symbol in superclasses.
177 */
178 Map<Symbol,Symbol> actualSymbols;
179
180 /**
181 * The current expected return type.
182 */
183 Type currentRestype;
184
185 /** The current method definition.
186 */
187 JCMethodDecl currentMethodDef;
188
189 /** The current method symbol.
190 */
191 MethodSymbol currentMethodSym;
192
193 /** The currently enclosing outermost class definition.
194 */
195 JCClassDecl outermostClassDef;
196
197 /** The currently enclosing outermost member definition.
198 */
199 JCTree outermostMemberDef;
200
201 /** A navigator class for assembling a mapping from local class symbols
202 * to class definition trees.
203 * There is only one case; all other cases simply traverse down the tree.
204 */
205 class ClassMap extends TreeScanner {
206
207 /** All encountered class defs are entered into classdefs table.
208 */
209 public void visitClassDef(JCClassDecl tree) {
210 classdefs.put(tree.sym, tree);
211 super.visitClassDef(tree);
212 }
213 }
214 ClassMap classMap = new ClassMap();
215
216 /** Map a class symbol to its definition.
217 * @param c The class symbol of which we want to determine the definition.
218 */
219 JCClassDecl classDef(ClassSymbol c) {
220 // First lookup the class in the classdefs table.
221 JCClassDecl def = classdefs.get(c);
222 if (def == null && outermostMemberDef != null) {
223 // If this fails, traverse outermost member definition, entering all
224 // local classes into classdefs, and try again.
225 classMap.scan(outermostMemberDef);
226 def = classdefs.get(c);
227 }
228 if (def == null) {
229 // If this fails, traverse outermost class definition, entering all
230 // local classes into classdefs, and try again.
231 classMap.scan(outermostClassDef);
232 def = classdefs.get(c);
233 }
234 return def;
235 }
236
237 /**
238 * Get the enum constants for the given enum class symbol, if known.
239 * They will only be found if they are defined within the same top-level
240 * class as the class being compiled, so it's safe to assume that they
241 * can't change at runtime due to a recompilation.
242 */
243 List<Name> enumNamesFor(ClassSymbol c) {
244
245 // Find the class definition and verify it is an enum class
246 final JCClassDecl classDef = classDef(c);
247 if (classDef == null ||
248 (classDef.mods.flags & ENUM) == 0 ||
249 (types.supertype(currentClass.type).tsym.flags() & ENUM) != 0) {
250 return null;
251 }
252
253 // Gather the enum identifiers
254 ListBuffer<Name> idents = new ListBuffer<>();
255 for (List<JCTree> defs = classDef.defs; defs.nonEmpty(); defs=defs.tail) {
256 if (defs.head.hasTag(VARDEF) &&
257 (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
258 JCVariableDecl var = (JCVariableDecl)defs.head;
259 idents.append(var.name);
260 }
261 }
262 return idents.toList();
263 }
264
265 /** A hash table mapping class symbols to lists of free variables.
266 * accessed by them. Only free variables of the method immediately containing
267 * a class are associated with that class.
268 */
269 Map<ClassSymbol,List<VarSymbol>> freevarCache;
270
271 /** A navigator class for collecting the free variables accessed
272 * from a local class.
273 */
274 public class FreeVarCollector extends CaptureScanner {
275
276 protected FreeVarCollector(JCTree ownerTree) {
277 super(ownerTree);
278 }
279
280 protected void addFreeVars(ClassSymbol c) {
281 List<VarSymbol> fvs = freevarCache.get(c);
282 if (fvs != null) {
283 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
284 addFreeVar(l.head);
285 }
286 }
287 }
288
289 /** If tree refers to a class instance creation expression
290 * add all free variables of the freshly created class.
291 */
292 public void visitNewClass(JCNewClass tree) {
293 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
294 addFreeVars(c);
295 super.visitNewClass(tree);
296 }
297
298 /** If tree refers to a superclass constructor call,
299 * add all free variables of the superclass.
300 */
301 public void visitApply(JCMethodInvocation tree) {
302 if (TreeInfo.name(tree.meth) == names._super) {
303 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner);
304 }
305 super.visitApply(tree);
306 }
307 }
308
309 /** Return the variables accessed from within a local class, which
310 * are declared in the local class' owner.
311 * (in reverse order of first access).
312 */
313 List<VarSymbol> freevars(ClassSymbol c) {
314 List<VarSymbol> fvs = freevarCache.get(c);
315 if (fvs != null) {
316 return fvs;
317 }
318 FreeVarCollector collector = new FreeVarCollector(classDef(c));
319 fvs = collector.analyzeCaptures().reverse();
320 freevarCache.put(c, fvs);
321 return fvs;
322 }
323
324 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>();
325
326 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) {
327
328 // If enum class is part of this compilation, just switch on ordinal value
329 if (enumClass.kind == TYP) {
330 final List<Name> idents = enumNamesFor((ClassSymbol)enumClass);
331 if (idents != null)
332 return new CompileTimeEnumMapping(idents);
333 }
334
335 // Map identifiers to ordinal values at runtime, and then switch on that
336 return enumSwitchMap.computeIfAbsent(enumClass, ec -> new RuntimeEnumMapping(pos, ec));
337 }
338
339 /** Generates a test value and corresponding cases for a switch on an enum type.
340 */
341 interface EnumMapping {
342
343 /** Given an expression for the enum value's ordinal, generate an expression for the switch statement.
344 */
345 JCExpression switchValue(JCExpression ordinalExpr);
346
347 /** Generate the switch statement case value corresponding to the given enum value.
348 */
349 JCLiteral caseValue(VarSymbol v);
350
351 default void translate() {
352 }
353 }
354
355 /** EnumMapping using compile-time constants. Only valid when compiling the enum class itself,
356 * because otherwise the ordinals we use could become obsolete if/when the enum class is recompiled.
357 */
358 class CompileTimeEnumMapping implements EnumMapping {
359
360 final List<Name> enumNames;
361
362 CompileTimeEnumMapping(List<Name> enumNames) {
363 Assert.check(enumNames != null);
364 this.enumNames = enumNames;
365 }
366
367 @Override
368 public JCExpression switchValue(JCExpression ordinalExpr) {
369 return ordinalExpr;
370 }
371
372 @Override
373 public JCLiteral caseValue(VarSymbol v) {
374 final int ordinal = enumNames.indexOf(v.name);
375 Assert.check(ordinal != -1);
376 return make.Literal(ordinal);
377 }
378 }
379
380 /** EnumMapping using run-time ordinal lookup.
381 *
382 * This builds a translation table to be used for enum switches.
383 *
384 * <p>For each enum that appears as the type of a switch
385 * expression, we maintain an EnumMapping to assist in the
386 * translation, as exemplified by the following example:
387 *
388 * <p>we translate
389 * <pre>
390 * switch(colorExpression) {
391 * case red: stmt1;
392 * case green: stmt2;
393 * }
394 * </pre>
395 * into
396 * <pre>
397 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) {
398 * case 1: stmt1;
399 * case 2: stmt2
400 * }
401 * </pre>
402 * with the auxiliary table initialized as follows:
403 * <pre>
404 * class Outer$0 {
405 * synthetic final int[] $EnumMap$Color = new int[Color.values().length];
406 * static {
407 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {}
408 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {}
409 * }
410 * }
411 * </pre>
412 * class EnumMapping provides mapping data and support methods for this translation.
413 */
414 class RuntimeEnumMapping implements EnumMapping {
415 RuntimeEnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) {
416 this.forEnum = forEnum;
417 this.values = new LinkedHashMap<>();
418 this.pos = pos;
419 Name varName = names
420 .fromString(target.syntheticNameChar() +
421 "SwitchMap" +
422 target.syntheticNameChar() +
423 ClassWriter.externalize(forEnum.type.tsym.flatName().toString())
424 .replace('/', '.')
425 .replace('.', target.syntheticNameChar()));
426 ClassSymbol outerCacheClass = outerCacheClass();
427 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL,
428 varName,
429 new ArrayType(syms.intType, syms.arrayClass),
430 outerCacheClass);
431 enterSynthetic(pos, mapVar, outerCacheClass.members());
432 }
433
434 DiagnosticPosition pos = null;
435
436 // the next value to use
437 int next = 1; // 0 (unused map elements) go to the default label
438
439 // the enum for which this is a map
440 final TypeSymbol forEnum;
441
442 // the field containing the map
443 final VarSymbol mapVar;
444
445 // the mapped values
446 final Map<VarSymbol,Integer> values;
447
448 @Override
449 public JCExpression switchValue(JCExpression ordinalExpr) {
450 return make.Indexed(mapVar, ordinalExpr);
451 }
452
453 @Override
454 public JCLiteral caseValue(VarSymbol v) {
455 Integer result = values.get(v);
456 if (result == null)
457 values.put(v, result = next++);
458 return make.Literal(result);
459 }
460
461 // generate the field initializer for the map
462 @Override
463 public void translate() {
464 boolean prevAllowProtectedAccess = attrEnv.info.allowProtectedAccess;
465 try {
466 make.at(pos.getStartPosition());
467 attrEnv.info.allowProtectedAccess = true;
468 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner);
469
470 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length];
471 MethodSymbol valuesMethod = lookupMethod(pos,
472 names.values,
473 forEnum.type,
474 List.nil());
475 JCExpression size = make // Color.values().length
476 .Select(make.App(make.QualIdent(valuesMethod)),
477 syms.lengthVar);
478 JCExpression mapVarInit = make
479 .NewArray(make.Type(syms.intType), List.of(size), null)
480 .setType(new ArrayType(syms.intType, syms.arrayClass));
481
482 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {}
483 ListBuffer<JCStatement> stmts = new ListBuffer<>();
484 Symbol ordinalMethod = lookupMethod(pos,
485 names.ordinal,
486 forEnum.type,
487 List.nil());
488 List<JCCatch> catcher = List.<JCCatch>nil()
489 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex,
490 syms.noSuchFieldErrorType,
491 syms.noSymbol),
492 null),
493 make.Block(0, List.nil())));
494 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) {
495 VarSymbol enumerator = e.getKey();
496 Integer mappedValue = e.getValue();
497 JCExpression assign = make
498 .Assign(make.Indexed(mapVar,
499 make.App(make.Select(make.QualIdent(enumerator),
500 ordinalMethod))),
501 make.Literal(mappedValue))
502 .setType(syms.intType);
503 JCStatement exec = make.Exec(assign);
504 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null);
505 stmts.append(_try);
506 }
507
508 owner.defs = owner.defs
509 .prepend(make.Block(STATIC, stmts.toList()))
510 .prepend(make.VarDef(mapVar, mapVarInit));
511 } finally {
512 attrEnv.info.allowProtectedAccess = prevAllowProtectedAccess;
513 }
514 }
515 }
516
517
518 /* ************************************************************************
519 * Tree building blocks
520 *************************************************************************/
521
522 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching
523 * pos as make_pos, for use in diagnostics.
524 **/
525 TreeMaker make_at(DiagnosticPosition pos) {
526 make_pos = pos;
527 return make.at(pos);
528 }
529
530 /** Make an attributed tree representing a literal. This will be an
531 * Ident node in the case of boolean literals, a Literal node in all
532 * other cases.
533 * @param type The literal's type.
534 * @param value The literal's value.
535 */
536 JCExpression makeLit(Type type, Object value) {
537 return make.Literal(type.getTag(), value).setType(type.constType(value));
538 }
539
540 /** Make an attributed tree representing null.
541 */
542 JCExpression makeNull() {
543 return makeLit(syms.botType, null);
544 }
545
546 /** Make an attributed class instance creation expression.
547 * @param ctype The class type.
548 * @param args The constructor arguments.
549 */
550 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
551 JCNewClass tree = make.NewClass(null,
552 null, make.QualIdent(ctype.tsym), args, null);
553 tree.constructor = rs.resolveConstructor(
554 make_pos, attrEnv, ctype, TreeInfo.types(args), List.nil());
555 tree.type = ctype;
556 return tree;
557 }
558
559 /** Make an attributed unary expression.
560 * @param optag The operators tree tag.
561 * @param arg The operator's argument.
562 */
563 JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) {
564 JCUnary tree = make.Unary(optag, arg);
565 tree.operator = operators.resolveUnary(tree, optag, arg.type);
566 tree.type = tree.operator.type.getReturnType();
567 return tree;
568 }
569
570 /** Make an attributed binary expression.
571 * @param optag The operators tree tag.
572 * @param lhs The operator's left argument.
573 * @param rhs The operator's right argument.
574 */
575 JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) {
576 JCBinary tree = make.Binary(optag, lhs, rhs);
577 tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type);
578 tree.type = tree.operator.type.getReturnType();
579 return tree;
580 }
581
582 /** Make an attributed assignop expression.
583 * @param optag The operators tree tag.
584 * @param lhs The operator's left argument.
585 * @param rhs The operator's right argument.
586 */
587 JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) {
588 JCAssignOp tree = make.Assignop(optag, lhs, rhs);
589 tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type);
590 tree.type = lhs.type;
591 return tree;
592 }
593
594 /** Convert tree into string object, unless it has already a
595 * reference type..
596 */
597 JCExpression makeString(JCExpression tree) {
598 if (!tree.type.isPrimitiveOrVoid()) {
599 return tree;
600 } else {
601 Symbol valueOfSym = lookupMethod(tree.pos(),
602 names.valueOf,
603 syms.stringType,
604 List.of(tree.type));
605 return make.App(make.QualIdent(valueOfSym), List.of(tree));
606 }
607 }
608
609 /** Create an empty anonymous class definition and enter and complete
610 * its symbol. Return the class definition's symbol.
611 * and create
612 * @param flags The class symbol's flags
613 * @param owner The class symbol's owner
614 */
615 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) {
616 return makeEmptyClass(flags, owner, null, true);
617 }
618
619 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname,
620 boolean addToDefs) {
621 // Create class symbol.
622 ClassSymbol c = syms.defineClass(names.empty, owner);
623 if (flatname != null) {
624 c.flatname = flatname;
625 } else {
626 c.flatname = chk.localClassName(c);
627 }
628 c.sourcefile = owner.sourcefile;
629 c.completer = Completer.NULL_COMPLETER;
630 c.members_field = WriteableScope.create(c);
631 c.flags_field = flags;
632 ClassType ctype = (ClassType) c.type;
633 ctype.supertype_field = syms.objectType;
634 ctype.interfaces_field = List.nil();
635
636 JCClassDecl odef = classDef(owner);
637
638 // Enter class symbol in owner scope and compiled table.
639 enterSynthetic(odef.pos(), c, owner.members());
640 chk.putCompiled(c);
641
642 // Create class definition tree.
643 JCClassDecl cdef = make.ClassDef(
644 make.Modifiers(flags), names.empty,
645 List.nil(),
646 null, List.nil(), List.nil());
647 cdef.sym = c;
648 cdef.type = c.type;
649
650 // Append class definition tree to owner's definitions.
651 if (addToDefs) odef.defs = odef.defs.prepend(cdef);
652 return cdef;
653 }
654
655 /* ************************************************************************
656 * Symbol manipulation utilities
657 *************************************************************************/
658
659 /** Enter a synthetic symbol in a given scope, but complain if there was already one there.
660 * @param pos Position for error reporting.
661 * @param sym The symbol.
662 * @param s The scope.
663 */
664 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) {
665 s.enter(sym);
666 }
667
668 /** Create a fresh synthetic name within a given scope - the unique name is
669 * obtained by appending '$' chars at the end of the name until no match
670 * is found.
671 *
672 * @param name base name
673 * @param s scope in which the name has to be unique
674 * @return fresh synthetic name
675 */
676 private Name makeSyntheticName(Name name, Scope s) {
677 do {
678 name = name.append(
679 target.syntheticNameChar(),
680 names.empty);
681 } while (lookupSynthetic(name, s) != null);
682 return name;
683 }
684
685 /** Check whether synthetic symbols generated during lowering conflict
686 * with user-defined symbols.
687 *
688 * @param translatedTrees lowered class trees
689 */
690 void checkConflicts(List<JCTree> translatedTrees) {
691 for (JCTree t : translatedTrees) {
692 t.accept(conflictsChecker);
693 }
694 }
695
696 JCTree.Visitor conflictsChecker = new TreeScanner() {
697
698 TypeSymbol currentClass;
699
700 @Override
701 public void visitMethodDef(JCMethodDecl that) {
702 checkConflicts(that.pos(), that.sym, currentClass);
703 super.visitMethodDef(that);
704 }
705
706 @Override
707 public void visitVarDef(JCVariableDecl that) {
708 if (that.sym.owner.kind == TYP) {
709 checkConflicts(that.pos(), that.sym, currentClass);
710 }
711 super.visitVarDef(that);
712 }
713
714 @Override
715 public void visitClassDef(JCClassDecl that) {
716 TypeSymbol prevCurrentClass = currentClass;
717 currentClass = that.sym;
718 try {
719 super.visitClassDef(that);
720 }
721 finally {
722 currentClass = prevCurrentClass;
723 }
724 }
725
726 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
727 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
728 for (Symbol sym2 : ct.tsym.members().getSymbolsByName(sym.name, NON_RECURSIVE)) {
729 // VM allows methods and variables with differing types
730 if (sym.kind == sym2.kind &&
731 types.isSameType(types.erasure(sym.type), types.erasure(sym2.type)) &&
732 sym != sym2 &&
733 (sym.flags() & Flags.SYNTHETIC) != (sym2.flags() & Flags.SYNTHETIC) &&
734 (sym.flags() & BRIDGE) == 0 && (sym2.flags() & BRIDGE) == 0) {
735 syntheticError(pos, (sym2.flags() & SYNTHETIC) == 0 ? sym2 : sym);
736 return;
737 }
738 }
739 }
740 }
741
742 /** Report a conflict between a user symbol and a synthetic symbol.
743 */
744 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
745 if (!sym.type.isErroneous()) {
746 log.error(pos, Errors.CannotGenerateClass(sym.location(), Fragments.SyntheticNameConflict(sym, sym.location())));
747 }
748 }
749 };
750
751 /** Look up a synthetic name in a given scope.
752 * @param s The scope.
753 * @param name The name.
754 */
755 private Symbol lookupSynthetic(Name name, Scope s) {
756 Symbol sym = s.findFirst(name);
757 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym;
758 }
759
760 /** Look up a method in a given scope.
761 */
762 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) {
763 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.nil());
764 }
765
766 /** Anon inner classes are used as access constructor tags.
767 * accessConstructorTag will use an existing anon class if one is available,
768 * and synthesize a class (with makeEmptyClass) if one is not available.
769 * However, there is a small possibility that an existing class will not
770 * be generated as expected if it is inside a conditional with a constant
771 * expression. If that is found to be the case, create an empty class tree here.
772 */
773 private void checkAccessConstructorTags() {
774 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) {
775 ClassSymbol c = l.head;
776 if (isTranslatedClassAvailable(c))
777 continue;
778 // Create class definition tree.
779 JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC,
780 c.outermostClass(), c.flatname, false);
781 swapAccessConstructorTag(c, cdec.sym);
782 translated.append(cdec);
783 }
784 }
785 // where
786 private boolean isTranslatedClassAvailable(ClassSymbol c) {
787 for (JCTree tree: translated) {
788 if (tree.hasTag(CLASSDEF)
789 && ((JCClassDecl) tree).sym == c) {
790 return true;
791 }
792 }
793 return false;
794 }
795
796 void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) {
797 for (MethodSymbol methodSymbol : accessConstrs.values()) {
798 Assert.check(methodSymbol.type.hasTag(METHOD));
799 MethodType oldMethodType =
800 (MethodType)methodSymbol.type;
801 if (oldMethodType.argtypes.head.tsym == oldCTag)
802 methodSymbol.type =
803 types.createMethodTypeWithParameters(oldMethodType,
804 oldMethodType.getParameterTypes().tail
805 .prepend(newCTag.erasure(types)));
806 }
807 }
808
809 /* ************************************************************************
810 * Access methods
811 *************************************************************************/
812
813 /** A mapping from symbols to their access numbers.
814 */
815 private Map<Symbol,Integer> accessNums;
816
817 /** A mapping from symbols to an array of access symbols, indexed by
818 * access code.
819 */
820 private Map<Symbol,MethodSymbol[]> accessSyms;
821
822 /** A mapping from (constructor) symbols to access constructor symbols.
823 */
824 private Map<Symbol,MethodSymbol> accessConstrs;
825
826 /** A list of all class symbols used for access constructor tags.
827 */
828 private List<ClassSymbol> accessConstrTags;
829
830 /** A queue for all accessed symbols.
831 */
832 private ListBuffer<Symbol> accessed;
833
834 /** return access code for identifier,
835 * @param tree The tree representing the identifier use.
836 * @param enclOp The closest enclosing operation node of tree,
837 * null if tree is not a subtree of an operation.
838 */
839 private static int accessCode(JCTree tree, JCTree enclOp) {
840 if (enclOp == null)
841 return AccessCode.DEREF.code;
842 else if (enclOp.hasTag(ASSIGN) &&
843 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs))
844 return AccessCode.ASSIGN.code;
845 else if ((enclOp.getTag().isIncOrDecUnaryOp() || enclOp.getTag().isAssignop()) &&
846 tree == TreeInfo.skipParens(((JCOperatorExpression) enclOp).getOperand(LEFT)))
847 return (((JCOperatorExpression) enclOp).operator).getAccessCode(enclOp.getTag());
848 else
849 return AccessCode.DEREF.code;
850 }
851
852 /** Return binary operator that corresponds to given access code.
853 */
854 private OperatorSymbol binaryAccessOperator(int acode, Tag tag) {
855 return operators.lookupBinaryOp(op -> op.getAccessCode(tag) == acode);
856 }
857
858 /** Return tree tag for assignment operation corresponding
859 * to given binary operator.
860 */
861 private static JCTree.Tag treeTag(OperatorSymbol operator) {
862 switch (operator.opcode) {
863 case ByteCodes.ior: case ByteCodes.lor:
864 return BITOR_ASG;
865 case ByteCodes.ixor: case ByteCodes.lxor:
866 return BITXOR_ASG;
867 case ByteCodes.iand: case ByteCodes.land:
868 return BITAND_ASG;
869 case ByteCodes.ishl: case ByteCodes.lshl:
870 case ByteCodes.ishll: case ByteCodes.lshll:
871 return SL_ASG;
872 case ByteCodes.ishr: case ByteCodes.lshr:
873 case ByteCodes.ishrl: case ByteCodes.lshrl:
874 return SR_ASG;
875 case ByteCodes.iushr: case ByteCodes.lushr:
876 case ByteCodes.iushrl: case ByteCodes.lushrl:
877 return USR_ASG;
878 case ByteCodes.iadd: case ByteCodes.ladd:
879 case ByteCodes.fadd: case ByteCodes.dadd:
880 case ByteCodes.string_add:
881 return PLUS_ASG;
882 case ByteCodes.isub: case ByteCodes.lsub:
883 case ByteCodes.fsub: case ByteCodes.dsub:
884 return MINUS_ASG;
885 case ByteCodes.imul: case ByteCodes.lmul:
886 case ByteCodes.fmul: case ByteCodes.dmul:
887 return MUL_ASG;
888 case ByteCodes.idiv: case ByteCodes.ldiv:
889 case ByteCodes.fdiv: case ByteCodes.ddiv:
890 return DIV_ASG;
891 case ByteCodes.imod: case ByteCodes.lmod:
892 case ByteCodes.fmod: case ByteCodes.dmod:
893 return MOD_ASG;
894 default:
895 throw new AssertionError();
896 }
897 }
898
899 /** The name of the access method with number `anum' and access code `acode'.
900 */
901 Name accessName(int anum, int acode) {
902 return names.fromString(
903 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10);
904 }
905
906 /** Return access symbol for a private or protected symbol from an inner class.
907 * @param sym The accessed private symbol.
908 * @param tree The accessing tree.
909 * @param enclOp The closest enclosing operation node of tree,
910 * null if tree is not a subtree of an operation.
911 * @param protAccess Is access to a protected symbol in another
912 * package?
913 * @param refSuper Is access via a (qualified) C.super?
914 */
915 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp,
916 boolean protAccess, boolean refSuper) {
917 ClassSymbol accOwner = refSuper && protAccess
918 // For access via qualified super (T.super.x), place the
919 // access symbol on T.
920 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym
921 // Otherwise pretend that the owner of an accessed
922 // protected symbol is the enclosing class of the current
923 // class which is a subclass of the symbol's owner.
924 : accessClass(sym, protAccess, tree);
925
926 Symbol vsym = sym;
927 if (sym.owner != accOwner) {
928 vsym = sym.clone(accOwner);
929 actualSymbols.put(vsym, sym);
930 }
931
932 Integer anum // The access number of the access method.
933 = accessNums.get(vsym);
934 if (anum == null) {
935 anum = accessed.length();
936 accessNums.put(vsym, anum);
937 accessSyms.put(vsym, new MethodSymbol[AccessCode.numberOfAccessCodes]);
938 accessed.append(vsym);
939 // System.out.println("accessing " + vsym + " in " + vsym.location());
940 }
941
942 int acode; // The access code of the access method.
943 List<Type> argtypes; // The argument types of the access method.
944 Type restype; // The result type of the access method.
945 List<Type> thrown; // The thrown exceptions of the access method.
946 switch (vsym.kind) {
947 case VAR:
948 acode = accessCode(tree, enclOp);
949 if (acode >= AccessCode.FIRSTASGOP.code) {
950 OperatorSymbol operator = binaryAccessOperator(acode, enclOp.getTag());
951 if (operator.opcode == string_add)
952 argtypes = List.of(syms.objectType);
953 else
954 argtypes = operator.type.getParameterTypes().tail;
955 } else if (acode == AccessCode.ASSIGN.code)
956 argtypes = List.of(vsym.erasure(types));
957 else
958 argtypes = List.nil();
959 restype = vsym.erasure(types);
960 thrown = List.nil();
961 break;
962 case MTH:
963 acode = AccessCode.DEREF.code;
964 argtypes = vsym.erasure(types).getParameterTypes();
965 restype = vsym.erasure(types).getReturnType();
966 thrown = vsym.type.getThrownTypes();
967 break;
968 default:
969 throw new AssertionError();
970 }
971
972 // For references via qualified super, increment acode by one,
973 // making it odd.
974 if (protAccess && refSuper) acode++;
975
976 // Instance access methods get instance as first parameter.
977 // For protected symbols this needs to be the instance as a member
978 // of the type containing the accessed symbol, not the class
979 // containing the access method.
980 if ((vsym.flags() & STATIC) == 0) {
981 argtypes = argtypes.prepend(vsym.owner.erasure(types));
982 }
983 MethodSymbol[] accessors = accessSyms.get(vsym);
984 MethodSymbol accessor = accessors[acode];
985 if (accessor == null) {
986 accessor = new MethodSymbol(
987 STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0),
988 accessName(anum.intValue(), acode),
989 new MethodType(argtypes, restype, thrown, syms.methodClass),
990 accOwner);
991 enterSynthetic(tree.pos(), accessor, accOwner.members());
992 accessors[acode] = accessor;
993 }
994 return accessor;
995 }
996
997 /** The qualifier to be used for accessing a symbol in an outer class.
998 * This is either C.sym or C.this.sym, depending on whether or not
999 * sym is static.
1000 * @param sym The accessed symbol.
1001 */
1002 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) {
1003 return (sym.flags() & STATIC) != 0
1004 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner))
1005 : makeOwnerThis(pos, sym, true);
1006 }
1007
1008 /** Do we need an access method to reference private symbol?
1009 */
1010 boolean needsPrivateAccess(Symbol sym) {
1011 if (target.hasNestmateAccess()) {
1012 return false;
1013 }
1014 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) {
1015 return false;
1016 } else if (sym.name == names.init && sym.owner.isDirectlyOrIndirectlyLocal()) {
1017 // private constructor in local class: relax protection
1018 sym.flags_field &= ~PRIVATE;
1019 return false;
1020 } else {
1021 return true;
1022 }
1023 }
1024
1025 /** Do we need an access method to reference symbol in other package?
1026 */
1027 boolean needsProtectedAccess(Symbol sym, JCTree tree) {
1028 if (disableProtectedAccessors) return false;
1029 if ((sym.flags() & PROTECTED) == 0 ||
1030 sym.owner.owner == currentClass.owner || // fast special case
1031 sym.packge() == currentClass.packge())
1032 return false;
1033 if (!currentClass.isSubClass(sym.owner, types))
1034 return true;
1035 if ((sym.flags() & STATIC) != 0 ||
1036 !tree.hasTag(SELECT) ||
1037 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super)
1038 return false;
1039 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types);
1040 }
1041
1042 /** The class in which an access method for given symbol goes.
1043 * @param sym The access symbol
1044 * @param protAccess Is access to a protected symbol in another
1045 * package?
1046 */
1047 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) {
1048 if (protAccess) {
1049 Symbol qualifier = null;
1050 ClassSymbol c = currentClass;
1051 if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) {
1052 qualifier = ((JCFieldAccess) tree).selected.type.tsym;
1053 while (!qualifier.isSubClass(c, types)) {
1054 c = c.owner.enclClass();
1055 }
1056 return c;
1057 } else {
1058 while (!c.isSubClass(sym.owner, types)) {
1059 c = c.owner.enclClass();
1060 }
1061 }
1062 return c;
1063 } else {
1064 // the symbol is private
1065 return sym.owner.enclClass();
1066 }
1067 }
1068
1069 private boolean noClassDefIn(JCTree tree) {
1070 var scanner = new TreeScanner() {
1071 boolean noClassDef = true;
1072 @Override
1073 public void visitClassDef(JCClassDecl tree) {
1074 noClassDef = false;
1075 }
1076 };
1077 scanner.scan(tree);
1078 return scanner.noClassDef;
1079 }
1080
1081 private void addPrunedInfo(JCTree tree) {
1082 List<JCTree> infoList = prunedTree.get(currentClass);
1083 infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree);
1084 prunedTree.put(currentClass, infoList);
1085 }
1086
1087 /** Ensure that identifier is accessible, return tree accessing the identifier.
1088 * @param sym The accessed symbol.
1089 * @param tree The tree referring to the symbol.
1090 * @param enclOp The closest enclosing operation node of tree,
1091 * null if tree is not a subtree of an operation.
1092 * @param refSuper Is access via a (qualified) C.super?
1093 */
1094 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) {
1095 // Access a free variable via its proxy, or its proxy's proxy
1096 while (sym.kind == VAR && sym.owner.kind == MTH &&
1097 sym.owner.enclClass() != currentClass) {
1098 // A constant is replaced by its constant value.
1099 Object cv = ((VarSymbol)sym).getConstValue();
1100 if (cv != null) {
1101 make.at(tree.pos);
1102 return makeLit(sym.type, cv);
1103 }
1104 // Otherwise replace the variable by its proxy.
1105 sym = proxies.get(sym);
1106 Assert.check(sym != null && (sym.flags_field & FINAL) != 0);
1107 tree = make.at(tree.pos).Ident(sym);
1108 }
1109 JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null;
1110 switch (sym.kind) {
1111 case TYP:
1112 if (sym.owner.kind != PCK) {
1113 // Convert type idents to
1114 // <flat name> or <package name> . <flat name>
1115 Name flatname = Convert.shortName(sym.flatName());
1116 while (base != null &&
1117 TreeInfo.symbol(base) != null &&
1118 TreeInfo.symbol(base).kind != PCK) {
1119 base = (base.hasTag(SELECT))
1120 ? ((JCFieldAccess) base).selected
1121 : null;
1122 }
1123 if (tree.hasTag(IDENT)) {
1124 ((JCIdent) tree).name = flatname;
1125 } else if (base == null) {
1126 tree = make.at(tree.pos).Ident(sym);
1127 ((JCIdent) tree).name = flatname;
1128 } else {
1129 ((JCFieldAccess) tree).selected = base;
1130 ((JCFieldAccess) tree).name = flatname;
1131 }
1132 }
1133 break;
1134 case MTH: case VAR:
1135 if (sym.owner.kind == TYP) {
1136
1137 // Access methods are required for
1138 // - private members,
1139 // - protected members in a superclass of an
1140 // enclosing class contained in another package.
1141 // - all non-private members accessed via a qualified super.
1142 boolean protAccess = refSuper && !needsPrivateAccess(sym)
1143 || needsProtectedAccess(sym, tree);
1144 boolean accReq = protAccess || needsPrivateAccess(sym);
1145
1146 // A base has to be supplied for
1147 // - simple identifiers accessing variables in outer classes.
1148 boolean baseReq =
1149 base == null &&
1150 sym.owner != syms.predefClass &&
1151 !sym.isMemberOf(currentClass, types);
1152
1153 if (accReq || baseReq) {
1154 make.at(tree.pos);
1155
1156 // Constants are replaced by their constant value.
1157 if (sym.kind == VAR) {
1158 Object cv = ((VarSymbol)sym).getConstValue();
1159 if (cv != null) {
1160 addPrunedInfo(tree);
1161 return makeLit(sym.type, cv);
1162 }
1163 }
1164
1165 // Private variables and methods are replaced by calls
1166 // to their access methods.
1167 if (accReq) {
1168 List<JCExpression> args = List.nil();
1169 if ((sym.flags() & STATIC) == 0) {
1170 // Instance access methods get instance
1171 // as first parameter.
1172 if (base == null)
1173 base = makeOwnerThis(tree.pos(), sym, true);
1174 args = args.prepend(base);
1175 base = null; // so we don't duplicate code
1176 }
1177 Symbol access = accessSymbol(sym, tree,
1178 enclOp, protAccess,
1179 refSuper);
1180 JCExpression receiver = make.Select(
1181 base != null ? base : make.QualIdent(access.owner),
1182 access);
1183 return make.App(receiver, args);
1184
1185 // Other accesses to members of outer classes get a
1186 // qualifier.
1187 } else if (baseReq) {
1188 return make.at(tree.pos).Select(
1189 accessBase(tree.pos(), sym), sym).setType(tree.type);
1190 }
1191 }
1192 }
1193 }
1194 return tree;
1195 }
1196
1197 /** Ensure that identifier is accessible, return tree accessing the identifier.
1198 * @param tree The identifier tree.
1199 */
1200 JCExpression access(JCExpression tree) {
1201 Symbol sym = TreeInfo.symbol(tree);
1202 return sym == null ? tree : access(sym, tree, null, false);
1203 }
1204
1205 /** Return access constructor for a private constructor,
1206 * or the constructor itself, if no access constructor is needed.
1207 * @param pos The position to report diagnostics, if any.
1208 * @param constr The private constructor.
1209 */
1210 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) {
1211 if (needsPrivateAccess(constr)) {
1212 ClassSymbol accOwner = constr.owner.enclClass();
1213 MethodSymbol aconstr = accessConstrs.get(constr);
1214 if (aconstr == null) {
1215 List<Type> argtypes = constr.type.getParameterTypes();
1216 if ((accOwner.flags_field & ENUM) != 0)
1217 argtypes = argtypes
1218 .prepend(syms.intType)
1219 .prepend(syms.stringType);
1220 aconstr = new MethodSymbol(
1221 SYNTHETIC,
1222 names.init,
1223 new MethodType(
1224 argtypes.append(
1225 accessConstructorTag().erasure(types)),
1226 constr.type.getReturnType(),
1227 constr.type.getThrownTypes(),
1228 syms.methodClass),
1229 accOwner);
1230 enterSynthetic(pos, aconstr, accOwner.members());
1231 accessConstrs.put(constr, aconstr);
1232 accessed.append(constr);
1233 }
1234 return aconstr;
1235 } else {
1236 return constr;
1237 }
1238 }
1239
1240 /** Return an anonymous class nested in this toplevel class.
1241 */
1242 ClassSymbol accessConstructorTag() {
1243 ClassSymbol topClass = currentClass.outermostClass();
1244 ModuleSymbol topModle = topClass.packge().modle;
1245 for (int i = 1; ; i++) {
1246 Name flatname = names.fromString("" + topClass.getQualifiedName() +
1247 target.syntheticNameChar() +
1248 i);
1249 ClassSymbol ctag = chk.getCompiled(topModle, flatname);
1250 if (ctag == null)
1251 ctag = makeEmptyClass(STATIC | SYNTHETIC, topClass).sym;
1252 else if (!ctag.isAnonymous())
1253 continue;
1254 // keep a record of all tags, to verify that all are generated as required
1255 accessConstrTags = accessConstrTags.prepend(ctag);
1256 return ctag;
1257 }
1258 }
1259
1260 /** Add all required access methods for a private symbol to enclosing class.
1261 * @param sym The symbol.
1262 */
1263 void makeAccessible(Symbol sym) {
1264 JCClassDecl cdef = classDef(sym.owner.enclClass());
1265 if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner);
1266 if (sym.name == names.init) {
1267 cdef.defs = cdef.defs.prepend(
1268 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym)));
1269 } else {
1270 MethodSymbol[] accessors = accessSyms.get(sym);
1271 for (int i = 0; i < AccessCode.numberOfAccessCodes; i++) {
1272 if (accessors[i] != null)
1273 cdef.defs = cdef.defs.prepend(
1274 accessDef(cdef.pos, sym, accessors[i], i));
1275 }
1276 }
1277 }
1278
1279 /** Construct definition of an access method.
1280 * @param pos The source code position of the definition.
1281 * @param vsym The private or protected symbol.
1282 * @param accessor The access method for the symbol.
1283 * @param acode The access code.
1284 */
1285 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) {
1286 // System.err.println("access " + vsym + " with " + accessor);//DEBUG
1287 currentClass = vsym.owner.enclClass();
1288 make.at(pos);
1289 JCMethodDecl md = make.MethodDef(accessor, null);
1290
1291 // Find actual symbol
1292 Symbol sym = actualSymbols.get(vsym);
1293 if (sym == null) sym = vsym;
1294
1295 JCExpression ref; // The tree referencing the private symbol.
1296 List<JCExpression> args; // Any additional arguments to be passed along.
1297 if ((sym.flags() & STATIC) != 0) {
1298 ref = make.Ident(sym);
1299 args = make.Idents(md.params);
1300 } else {
1301 JCExpression site = make.Ident(md.params.head);
1302 if (acode % 2 != 0) {
1303 //odd access codes represent qualified super accesses - need to
1304 //emit reference to the direct superclass, even if the referred
1305 //member is from an indirect superclass (JLS 13.1)
1306 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type)));
1307 }
1308 ref = make.Select(site, sym);
1309 args = make.Idents(md.params.tail);
1310 }
1311 JCStatement stat; // The statement accessing the private symbol.
1312 if (sym.kind == VAR) {
1313 // Normalize out all odd access codes by taking floor modulo 2:
1314 int acode1 = acode - (acode & 1);
1315
1316 JCExpression expr; // The access method's return value.
1317 AccessCode aCode = AccessCode.getFromCode(acode1);
1318 switch (aCode) {
1319 case DEREF:
1320 expr = ref;
1321 break;
1322 case ASSIGN:
1323 expr = make.Assign(ref, args.head);
1324 break;
1325 case PREINC: case POSTINC: case PREDEC: case POSTDEC:
1326 expr = makeUnary(aCode.tag, ref);
1327 break;
1328 default:
1329 expr = make.Assignop(
1330 treeTag(binaryAccessOperator(acode1, JCTree.Tag.NO_TAG)), ref, args.head);
1331 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1, JCTree.Tag.NO_TAG);
1332 }
1333 stat = make.Return(expr.setType(sym.type));
1334 } else {
1335 stat = make.Call(make.App(ref, args));
1336 }
1337 md.body = make.Block(0, List.of(stat));
1338
1339 // Make sure all parameters, result types and thrown exceptions
1340 // are accessible.
1341 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail)
1342 l.head.vartype = access(l.head.vartype);
1343 md.restype = access(md.restype);
1344 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail)
1345 l.head = access(l.head);
1346
1347 return md;
1348 }
1349
1350 /** Construct definition of an access constructor.
1351 * @param pos The source code position of the definition.
1352 * @param constr The private constructor.
1353 * @param accessor The access method for the constructor.
1354 */
1355 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) {
1356 make.at(pos);
1357 JCMethodDecl md = make.MethodDef(accessor,
1358 accessor.externalType(types),
1359 null);
1360 JCIdent callee = make.Ident(names._this);
1361 callee.sym = constr;
1362 callee.type = constr.type;
1363 md.body =
1364 make.Block(0, List.of(
1365 make.Call(
1366 make.App(
1367 callee,
1368 make.Idents(md.params.reverse().tail.reverse())))));
1369 return md;
1370 }
1371
1372 /* ************************************************************************
1373 * Free variables proxies and this$n
1374 *************************************************************************/
1375
1376 /** A map which allows to retrieve the translated proxy variable for any given symbol of an
1377 * enclosing scope that is accessed (the accessed symbol could be the synthetic 'this$n' symbol).
1378 * Inside a constructor, the map temporarily overrides entries corresponding to proxies and any
1379 * 'this$n' symbols, where they represent the constructor parameters.
1380 */
1381 Map<Symbol, Symbol> proxies;
1382
1383 /** A scope containing all unnamed resource variables/saved
1384 * exception variables for translated TWR blocks
1385 */
1386 WriteableScope twrVars;
1387
1388 /** A stack containing the this$n field of the currently translated
1389 * classes (if needed) in innermost first order.
1390 * Inside a constructor, proxies and any this$n symbol are duplicated
1391 * in an additional innermost scope, where they represent the constructor
1392 * parameters.
1393 */
1394 List<VarSymbol> outerThisStack;
1395
1396 /** The name of a free variable proxy.
1397 */
1398 Name proxyName(Name name, int index) {
1399 Name proxyName = names.fromString("val" + target.syntheticNameChar() + name);
1400 if (index > 0) {
1401 proxyName = proxyName.append(names.fromString("" + target.syntheticNameChar() + index));
1402 }
1403 return proxyName;
1404 }
1405
1406 /** Proxy definitions for all free variables in given list, in reverse order.
1407 * @param pos The source code position of the definition.
1408 * @param freevars The free variables.
1409 * @param owner The class in which the definitions go.
1410 */
1411 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) {
1412 return freevarDefs(pos, freevars, owner, LOCAL_CAPTURE_FIELD);
1413 }
1414
1415 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner,
1416 long additionalFlags) {
1417 long flags = FINAL | SYNTHETIC | additionalFlags;
1418 List<JCVariableDecl> defs = List.nil();
1419 Set<Name> proxyNames = new HashSet<>();
1420 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail) {
1421 VarSymbol v = l.head;
1422 int index = 0;
1423 Name proxyName;
1424 do {
1425 proxyName = proxyName(v.name, index++);
1426 } while (!proxyNames.add(proxyName));
1427 VarSymbol proxy = new VarSymbol(
1428 flags, proxyName, v.erasure(types), owner) {
1429 @Override
1430 public Symbol baseSymbol() {
1431 return v;
1432 }
1433 };
1434 proxies.put(v, proxy);
1435 JCVariableDecl vd = make.at(pos).VarDef(proxy, null);
1436 vd.vartype = access(vd.vartype);
1437 defs = defs.prepend(vd);
1438 }
1439 return defs;
1440 }
1441
1442 /** The name of a this$n field
1443 * @param type The class referenced by the this$n field
1444 */
1445 Name outerThisName(Type type, Symbol owner) {
1446 Type t = type.getEnclosingType();
1447 int nestingLevel = 0;
1448 while (t.hasTag(CLASS)) {
1449 t = t.getEnclosingType();
1450 nestingLevel++;
1451 }
1452 Name result = names.fromString("this" + target.syntheticNameChar() + nestingLevel);
1453 while (owner.kind == TYP && ((ClassSymbol)owner).members().findFirst(result) != null)
1454 result = names.fromString(result.toString() + target.syntheticNameChar());
1455 return result;
1456 }
1457
1458 private VarSymbol makeOuterThisVarSymbol(Symbol owner, long flags) {
1459 Type target = owner.innermostAccessibleEnclosingClass().erasure(types);
1460 // Set NOOUTERTHIS for all synthetic outer instance variables, and unset
1461 // it when the variable is accessed. If the variable is never accessed,
1462 // we skip creating an outer instance field and saving the constructor
1463 // parameter to it.
1464 VarSymbol outerThis =
1465 new VarSymbol(flags | NOOUTERTHIS, outerThisName(target, owner), target, owner);
1466 outerThisStack = outerThisStack.prepend(outerThis);
1467 return outerThis;
1468 }
1469
1470 private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) {
1471 JCVariableDecl vd = make.at(pos).VarDef(sym, null);
1472 vd.vartype = access(vd.vartype);
1473 return vd;
1474 }
1475
1476 /** Definition for this$n field.
1477 * @param pos The source code position of the definition.
1478 * @param owner The method in which the definition goes.
1479 */
1480 JCVariableDecl outerThisDef(int pos, MethodSymbol owner) {
1481 ClassSymbol c = owner.enclClass();
1482 boolean isMandated =
1483 // Anonymous constructors
1484 (owner.isConstructor() && owner.isAnonymous()) ||
1485 // Constructors of non-private inner member classes
1486 (owner.isConstructor() && c.isInner() &&
1487 !c.isPrivate() && !c.isStatic());
1488 long flags =
1489 FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER;
1490 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags);
1491 owner.extraParams = owner.extraParams.prepend(outerThis);
1492 return makeOuterThisVarDecl(pos, outerThis);
1493 }
1494
1495 /** Definition for this$n field.
1496 * @param pos The source code position of the definition.
1497 * @param owner The class in which the definition goes.
1498 */
1499 JCVariableDecl outerThisDef(int pos, ClassSymbol owner) {
1500 VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC);
1501 return makeOuterThisVarDecl(pos, outerThis);
1502 }
1503
1504 /** Return a list of trees that load the free variables in given list,
1505 * in reverse order.
1506 * @param pos The source code position to be used for the trees.
1507 * @param freevars The list of free variables.
1508 */
1509 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) {
1510 List<JCExpression> args = List.nil();
1511 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail)
1512 args = args.prepend(loadFreevar(pos, l.head));
1513 return args;
1514 }
1515 //where
1516 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) {
1517 return access(v, make.at(pos).Ident(v), null, false);
1518 }
1519
1520 /** Construct a tree simulating the expression {@code C.this}.
1521 * @param pos The source code position to be used for the tree.
1522 * @param c The qualifier class.
1523 */
1524 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) {
1525 if (currentClass == c) {
1526 // in this case, `this' works fine
1527 return make.at(pos).This(c.erasure(types));
1528 } else {
1529 // need to go via this$n
1530 return makeOuterThis(pos, c);
1531 }
1532 }
1533
1534 /**
1535 * Optionally replace a try statement with the desugaring of a
1536 * try-with-resources statement. The canonical desugaring of
1537 *
1538 * try ResourceSpecification
1539 * Block
1540 *
1541 * is
1542 *
1543 * {
1544 * final VariableModifiers_minus_final R #resource = Expression;
1545 *
1546 * try ResourceSpecificationtail
1547 * Block
1548 * } body-only-finally {
1549 * if (#resource != null) //nullcheck skipped if Expression is provably non-null
1550 * #resource.close();
1551 * } catch (Throwable #primaryException) {
1552 * if (#resource != null) //nullcheck skipped if Expression is provably non-null
1553 * try {
1554 * #resource.close();
1555 * } catch (Throwable #suppressedException) {
1556 * #primaryException.addSuppressed(#suppressedException);
1557 * }
1558 * throw #primaryException;
1559 * }
1560 * }
1561 *
1562 * @param tree The try statement to inspect.
1563 * @return a desugared try-with-resources tree, or the original
1564 * try block if there are no resources to manage.
1565 */
1566 JCTree makeTwrTry(JCTry tree) {
1567 make_at(tree.pos());
1568 twrVars = twrVars.dup();
1569 JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body, 0);
1570 if (tree.catchers.isEmpty() && tree.finalizer == null)
1571 result = translate(twrBlock);
1572 else
1573 result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer));
1574 twrVars = twrVars.leave();
1575 return result;
1576 }
1577
1578 private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block, int depth) {
1579 if (resources.isEmpty())
1580 return block;
1581
1582 // Add resource declaration or expression to block statements
1583 ListBuffer<JCStatement> stats = new ListBuffer<>();
1584 JCTree resource = resources.head;
1585 JCExpression resourceUse;
1586 boolean resourceNonNull;
1587 if (resource instanceof JCVariableDecl variableDecl) {
1588 resourceUse = make.Ident(variableDecl.sym).setType(resource.type);
1589 resourceNonNull = variableDecl.init != null && TreeInfo.skipParens(variableDecl.init).hasTag(NEWCLASS);
1590 stats.add(variableDecl);
1591 } else {
1592 Assert.check(resource instanceof JCExpression);
1593 VarSymbol syntheticTwrVar =
1594 new VarSymbol(SYNTHETIC | FINAL,
1595 makeSyntheticName(names.fromString("twrVar" +
1596 depth), twrVars),
1597 (resource.type.hasTag(BOT)) ?
1598 syms.autoCloseableType : resource.type,
1599 currentMethodSym);
1600 twrVars.enter(syntheticTwrVar);
1601 JCVariableDecl syntheticTwrVarDecl =
1602 make.VarDef(syntheticTwrVar, (JCExpression)resource);
1603 resourceUse = (JCExpression)make.Ident(syntheticTwrVar);
1604 resourceNonNull = false;
1605 stats.add(syntheticTwrVarDecl);
1606 }
1607
1608 //create (semi-) finally block that will be copied into the main try body:
1609 int oldPos = make.pos;
1610 make.at(TreeInfo.endPos(block));
1611
1612 // if (#resource != null) { #resource.close(); }
1613 JCStatement bodyCloseStatement = makeResourceCloseInvocation(resourceUse);
1614
1615 if (!resourceNonNull) {
1616 bodyCloseStatement = make.If(makeNonNullCheck(resourceUse),
1617 bodyCloseStatement,
1618 null);
1619 }
1620
1621 JCBlock finallyClause = make.Block(BODY_ONLY_FINALIZE, List.of(bodyCloseStatement));
1622 make.at(oldPos);
1623
1624 // Create catch clause that saves exception, closes the resource and then rethrows the exception:
1625 VarSymbol primaryException =
1626 new VarSymbol(FINAL|SYNTHETIC,
1627 names.fromString("t" +
1628 target.syntheticNameChar()),
1629 syms.throwableType,
1630 currentMethodSym);
1631 JCVariableDecl primaryExceptionDecl = make.VarDef(primaryException, null);
1632
1633 // close resource:
1634 // try {
1635 // #resource.close();
1636 // } catch (Throwable #suppressedException) {
1637 // #primaryException.addSuppressed(#suppressedException);
1638 // }
1639 VarSymbol suppressedException =
1640 new VarSymbol(SYNTHETIC, make.paramName(2),
1641 syms.throwableType,
1642 currentMethodSym);
1643 JCStatement addSuppressedStatement =
1644 make.Exec(makeCall(make.Ident(primaryException),
1645 names.addSuppressed,
1646 List.of(make.Ident(suppressedException))));
1647 JCBlock closeResourceTryBlock =
1648 make.Block(0L, List.of(makeResourceCloseInvocation(resourceUse)));
1649 JCVariableDecl catchSuppressedDecl = make.VarDef(suppressedException, null);
1650 JCBlock catchSuppressedBlock = make.Block(0L, List.of(addSuppressedStatement));
1651 List<JCCatch> catchSuppressedClauses =
1652 List.of(make.Catch(catchSuppressedDecl, catchSuppressedBlock));
1653 JCTry closeResourceTry = make.Try(closeResourceTryBlock, catchSuppressedClauses, null);
1654 closeResourceTry.finallyCanCompleteNormally = true;
1655
1656 JCStatement exceptionalCloseStatement = closeResourceTry;
1657
1658 if (!resourceNonNull) {
1659 // if (#resource != null) { }
1660 exceptionalCloseStatement = make.If(makeNonNullCheck(resourceUse),
1661 exceptionalCloseStatement,
1662 null);
1663 }
1664
1665 JCStatement exceptionalRethrow = make.Throw(make.Ident(primaryException));
1666 JCBlock exceptionalCloseBlock = make.Block(0L, List.of(exceptionalCloseStatement, exceptionalRethrow));
1667 JCCatch exceptionalCatchClause = make.Catch(primaryExceptionDecl, exceptionalCloseBlock);
1668
1669 //create the main try statement with the close:
1670 JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block, depth + 1),
1671 List.of(exceptionalCatchClause),
1672 finallyClause);
1673
1674 outerTry.finallyCanCompleteNormally = true;
1675 stats.add(outerTry);
1676
1677 JCBlock newBlock = make.Block(0L, stats.toList());
1678 return newBlock;
1679 }
1680
1681 private JCStatement makeResourceCloseInvocation(JCExpression resource) {
1682 // convert to AutoCloseable if needed
1683 if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) {
1684 resource = convert(resource, syms.autoCloseableType);
1685 }
1686
1687 // create resource.close() method invocation
1688 JCExpression resourceClose = makeCall(resource,
1689 names.close,
1690 List.nil());
1691 return make.Exec(resourceClose);
1692 }
1693
1694 private JCExpression makeNonNullCheck(JCExpression expression) {
1695 return makeBinary(NE, expression, makeNull());
1696 }
1697
1698 /** Construct a tree that represents the outer instance
1699 * {@code C.this}. Never pick the current `this'.
1700 * @param pos The source code position to be used for the tree.
1701 * @param c The qualifier class.
1702 */
1703 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) {
1704 List<VarSymbol> ots = outerThisStack;
1705 if (ots.isEmpty()) {
1706 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1707 return makeNull();
1708 }
1709 VarSymbol ot = ots.head;
1710 JCExpression tree = access(make.at(pos).Ident(ot));
1711 ot.flags_field &= ~NOOUTERTHIS;
1712 TypeSymbol otc = ot.type.tsym;
1713 while (otc != c) {
1714 do {
1715 ots = ots.tail;
1716 if (ots.isEmpty()) {
1717 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1718 Assert.error(); // should have been caught in Attr
1719 return tree;
1720 }
1721 ot = ots.head;
1722 } while (ot.owner != otc);
1723 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) {
1724 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1725 Assert.error(); // should have been caught in Attr
1726 return makeNull();
1727 }
1728 tree = access(make.at(pos).Select(tree, ot));
1729 ot.flags_field &= ~NOOUTERTHIS;
1730 otc = ot.type.tsym;
1731 }
1732 return tree;
1733 }
1734
1735 /** Construct a tree that represents the closest outer instance
1736 * {@code C.this} such that the given symbol is a member of C.
1737 * @param pos The source code position to be used for the tree.
1738 * @param sym The accessed symbol.
1739 * @param preciseMatch should we accept a type that is a subtype of
1740 * sym's owner, even if it doesn't contain sym
1741 * due to hiding, overriding, or non-inheritance
1742 * due to protection?
1743 */
1744 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1745 if (preciseMatch ? sym.isMemberOf(currentClass, types)
1746 : currentClass.isSubClass(sym.owner, types)) {
1747 // in this case, `this' works fine
1748 return make.at(pos).This(currentClass.erasure(types));
1749 } else {
1750 // need to go via this$n
1751 return makeOwnerThisN(pos, sym, preciseMatch);
1752 }
1753 }
1754
1755 /**
1756 * Similar to makeOwnerThis but will never pick "this".
1757 */
1758 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1759 Symbol c = sym.owner;
1760 List<VarSymbol> ots = outerThisStack;
1761 if (ots.isEmpty()) {
1762 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1763 return makeNull();
1764 }
1765 VarSymbol ot = ots.head;
1766 JCExpression tree = access(make.at(pos).Ident(ot));
1767 ot.flags_field &= ~NOOUTERTHIS;
1768 TypeSymbol otc = ot.type.tsym;
1769 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) {
1770 do {
1771 ots = ots.tail;
1772 if (ots.isEmpty()) {
1773 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1774 return tree;
1775 }
1776 ot = ots.head;
1777 } while (ot.owner != otc);
1778 tree = access(make.at(pos).Select(tree, ot));
1779 ot.flags_field &= ~NOOUTERTHIS;
1780 otc = ot.type.tsym;
1781 }
1782 return tree;
1783 }
1784
1785 /** Return tree simulating the assignment {@code this.name = name}, where
1786 * name is the name of a free variable.
1787 */
1788 JCStatement initField(int pos, Symbol rhs, Symbol lhs) {
1789 Assert.check(rhs.owner.kind == MTH);
1790 Assert.check(rhs.owner.owner == lhs.owner);
1791 make.at(pos);
1792 return
1793 make.Exec(
1794 make.Assign(
1795 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1796 make.Ident(rhs)).setType(lhs.erasure(types)));
1797 }
1798
1799 /**
1800 * Return tree simulating null checking outer this and/or assigning. This is
1801 * called when a null check is required (nullCheckOuterThis), or a synthetic
1802 * field is generated (stores).
1803 */
1804 JCStatement initOuterThis(int pos, VarSymbol rhs, boolean stores) {
1805 Assert.check(rhs.owner.kind == MTH);
1806 Assert.check(nullCheckOuterThis || stores); // One of the flags must be true
1807 make.at(pos);
1808 JCExpression expression = make.Ident(rhs);
1809 if (nullCheckOuterThis) {
1810 expression = attr.makeNullCheck(expression);
1811 }
1812 if (stores) {
1813 VarSymbol lhs = outerThisStack.head;
1814 Assert.check(rhs.owner.owner == lhs.owner);
1815 expression = make.Assign(
1816 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1817 expression).setType(lhs.erasure(types));
1818 }
1819 return make.Exec(expression);
1820 }
1821
1822 /* ************************************************************************
1823 * Code for .class
1824 *************************************************************************/
1825
1826 /** Return the symbol of a class to contain a cache of
1827 * compiler-generated statics such as class$ and the
1828 * $assertionsDisabled flag. We create an anonymous nested class
1829 * (unless one already exists) and return its symbol. However,
1830 * for backward compatibility in 1.4 and earlier we use the
1831 * top-level class itself.
1832 */
1833 private ClassSymbol outerCacheClass() {
1834 ClassSymbol clazz = outermostClassDef.sym;
1835 Scope s = clazz.members();
1836 for (Symbol sym : s.getSymbols(NON_RECURSIVE))
1837 if (sym.kind == TYP &&
1838 sym.name == names.empty &&
1839 (sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym;
1840 return makeEmptyClass(STATIC | SYNTHETIC, clazz).sym;
1841 }
1842
1843 /** Create an attributed tree of the form left.name(). */
1844 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) {
1845 Assert.checkNonNull(left.type);
1846 Symbol funcsym = lookupMethod(make_pos, name, left.type,
1847 TreeInfo.types(args));
1848 return make.App(make.Select(left, funcsym), args);
1849 }
1850
1851 /** The tree simulating a T.class expression.
1852 * @param clazz The tree identifying type T.
1853 */
1854 private JCExpression classOf(JCTree clazz) {
1855 return classOfType(clazz.type, clazz.pos());
1856 }
1857
1858 private JCExpression classOfType(Type type, DiagnosticPosition pos) {
1859 switch (type.getTag()) {
1860 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT:
1861 case DOUBLE: case BOOLEAN: case VOID:
1862 // replace with <BoxedClass>.TYPE
1863 ClassSymbol c = types.boxedClass(type);
1864 Symbol typeSym =
1865 rs.accessBase(
1866 rs.findIdentInType(pos, attrEnv, c.type, names.TYPE, KindSelector.VAR),
1867 pos, c.type, names.TYPE, true);
1868 if (typeSym.kind == VAR)
1869 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated
1870 return make.QualIdent(typeSym);
1871 case CLASS: case ARRAY:
1872 VarSymbol sym = new VarSymbol(
1873 STATIC | PUBLIC | FINAL, names._class,
1874 syms.classType, type.tsym);
1875 return make_at(pos).Select(make.Type(type), sym);
1876 default:
1877 throw new AssertionError();
1878 }
1879 }
1880
1881 /* ************************************************************************
1882 * Code for enabling/disabling assertions.
1883 *************************************************************************/
1884
1885 private ClassSymbol assertionsDisabledClassCache;
1886
1887 /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces.
1888 */
1889 private ClassSymbol assertionsDisabledClass() {
1890 if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache;
1891
1892 assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC, outermostClassDef.sym).sym;
1893
1894 return assertionsDisabledClassCache;
1895 }
1896
1897 // This code is not particularly robust if the user has
1898 // previously declared a member named '$assertionsDisabled'.
1899 // The same faulty idiom also appears in the translation of
1900 // class literals above. We should report an error if a
1901 // previous declaration is not synthetic.
1902
1903 private JCExpression assertFlagTest(DiagnosticPosition pos) {
1904 // Outermost class may be either true class or an interface.
1905 ClassSymbol outermostClass = outermostClassDef.sym;
1906
1907 //only classes can hold a non-public field, look for a usable one:
1908 ClassSymbol container = !currentClass.isInterface() ? currentClass :
1909 assertionsDisabledClass();
1910
1911 VarSymbol assertDisabledSym =
1912 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled,
1913 container.members());
1914 if (assertDisabledSym == null) {
1915 assertDisabledSym =
1916 new VarSymbol(STATIC | FINAL | SYNTHETIC,
1917 dollarAssertionsDisabled,
1918 syms.booleanType,
1919 container);
1920 enterSynthetic(pos, assertDisabledSym, container.members());
1921 Symbol desiredAssertionStatusSym = lookupMethod(pos,
1922 names.desiredAssertionStatus,
1923 types.erasure(syms.classType),
1924 List.nil());
1925 JCClassDecl containerDef = classDef(container);
1926 make_at(containerDef.pos());
1927 JCExpression notStatus = makeUnary(NOT, make.App(make.Select(
1928 classOfType(types.erasure(outermostClass.type),
1929 containerDef.pos()),
1930 desiredAssertionStatusSym)));
1931 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym,
1932 notStatus);
1933 containerDef.defs = containerDef.defs.prepend(assertDisabledDef);
1934
1935 if (currentClass.isInterface()) {
1936 //need to load the assertions enabled/disabled state while
1937 //initializing the interface:
1938 JCClassDecl currentClassDef = classDef(currentClass);
1939 make_at(currentClassDef.pos());
1940 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null);
1941 JCBlock clinit = make.Block(STATIC, List.of(dummy));
1942 currentClassDef.defs = currentClassDef.defs.prepend(clinit);
1943 }
1944 }
1945 make_at(pos);
1946 return makeUnary(NOT, make.Ident(assertDisabledSym));
1947 }
1948
1949
1950 /* ************************************************************************
1951 * Building blocks for let expressions
1952 *************************************************************************/
1953
1954 interface TreeBuilder {
1955 JCExpression build(JCExpression arg);
1956 }
1957
1958 /** Construct an expression using the builder, with the given rval
1959 * expression as an argument to the builder. However, the rval
1960 * expression must be computed only once, even if used multiple
1961 * times in the result of the builder. We do that by
1962 * constructing a "let" expression that saves the rvalue into a
1963 * temporary variable and then uses the temporary variable in
1964 * place of the expression built by the builder. The complete
1965 * resulting expression is of the form
1966 * <pre>
1967 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>;
1968 * in (<b>BUILDER</b>(<b>TEMP</b>)))
1969 * </pre>
1970 * where <code><b>TEMP</b></code> is a newly declared variable
1971 * in the let expression.
1972 */
1973 JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) {
1974 rval = TreeInfo.skipParens(rval);
1975 switch (rval.getTag()) {
1976 case LITERAL:
1977 return builder.build(rval);
1978 case IDENT:
1979 JCIdent id = (JCIdent) rval;
1980 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH)
1981 return builder.build(rval);
1982 }
1983 Name name = TreeInfo.name(rval);
1984 if (name == names._super || name == names._this)
1985 return builder.build(rval);
1986 VarSymbol var =
1987 new VarSymbol(FINAL|SYNTHETIC,
1988 names.fromString(
1989 target.syntheticNameChar()
1990 + "" + rval.hashCode()),
1991 type,
1992 currentMethodSym);
1993 rval = convert(rval,type);
1994 JCVariableDecl def = make.VarDef(var, rval); // XXX cast
1995 JCExpression built = builder.build(make.Ident(var));
1996 JCExpression res = make.LetExpr(def, built);
1997 res.type = built.type;
1998 return res;
1999 }
2000
2001 // same as above, with the type of the temporary variable computed
2002 JCExpression abstractRval(JCExpression rval, TreeBuilder builder) {
2003 return abstractRval(rval, rval.type, builder);
2004 }
2005
2006 // same as above, but for an expression that may be used as either
2007 // an rvalue or an lvalue. This requires special handling for
2008 // Select expressions, where we place the left-hand-side of the
2009 // select in a temporary, and for Indexed expressions, where we
2010 // place both the indexed expression and the index value in temps.
2011 JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) {
2012 lval = TreeInfo.skipParens(lval);
2013 switch (lval.getTag()) {
2014 case IDENT:
2015 return builder.build(lval);
2016 case SELECT: {
2017 final JCFieldAccess s = (JCFieldAccess)lval;
2018 Symbol lid = TreeInfo.symbol(s.selected);
2019 if (lid != null && lid.kind == TYP) return builder.build(lval);
2020 return abstractRval(s.selected, selected -> builder.build(make.Select(selected, s.sym)));
2021 }
2022 case INDEXED: {
2023 final JCArrayAccess i = (JCArrayAccess)lval;
2024 return abstractRval(i.indexed, indexed -> abstractRval(i.index, syms.intType, index -> {
2025 JCExpression newLval = make.Indexed(indexed, index);
2026 newLval.setType(i.type);
2027 return builder.build(newLval);
2028 }));
2029 }
2030 case TYPECAST: {
2031 return abstractLval(((JCTypeCast)lval).expr, builder);
2032 }
2033 }
2034 throw new AssertionError(lval);
2035 }
2036
2037 // evaluate and discard the first expression, then evaluate the second.
2038 JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) {
2039 JCExpression res = make.LetExpr(List.of(make.Exec(expr1)), expr2);
2040 res.type = expr2.type;
2041 return res;
2042 }
2043
2044 /* ************************************************************************
2045 * Translation methods
2046 *************************************************************************/
2047
2048 /** Visitor argument: enclosing operator node.
2049 */
2050 private JCExpression enclOp;
2051
2052 /** Visitor method: Translate a single node.
2053 * Attach the source position from the old tree to its replacement tree.
2054 */
2055 @Override
2056 public <T extends JCTree> T translate(T tree) {
2057 if (tree == null) {
2058 return null;
2059 } else {
2060 make_at(tree.pos());
2061 T result = super.translate(tree);
2062 if (endPosTable != null && result != tree) {
2063 endPosTable.replaceTree(tree, result);
2064 }
2065 return result;
2066 }
2067 }
2068
2069 /** Visitor method: Translate a single node, boxing or unboxing if needed.
2070 */
2071 public <T extends JCExpression> T translate(T tree, Type type) {
2072 return (tree == null) ? null : boxIfNeeded(translate(tree), type);
2073 }
2074
2075 /** Visitor method: Translate tree.
2076 */
2077 public <T extends JCTree> T translate(T tree, JCExpression enclOp) {
2078 JCExpression prevEnclOp = this.enclOp;
2079 this.enclOp = enclOp;
2080 T res = translate(tree);
2081 this.enclOp = prevEnclOp;
2082 return res;
2083 }
2084
2085 /** Visitor method: Translate list of trees.
2086 */
2087 public <T extends JCExpression> List<T> translate(List<T> trees, Type type) {
2088 if (trees == null) return null;
2089 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
2090 l.head = translate(l.head, type);
2091 return trees;
2092 }
2093
2094 public void visitPackageDef(JCPackageDecl tree) {
2095 if (!needPackageInfoClass(tree))
2096 return;
2097
2098 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2099 // package-info is marked SYNTHETIC in JDK 1.6 and later releases
2100 flags = flags | Flags.SYNTHETIC;
2101 ClassSymbol c = tree.packge.package_info;
2102 c.setAttributes(tree.packge);
2103 c.flags_field |= flags;
2104 ClassType ctype = (ClassType) c.type;
2105 ctype.supertype_field = syms.objectType;
2106 ctype.interfaces_field = List.nil();
2107 createInfoClass(tree.annotations, c);
2108 }
2109 // where
2110 private boolean needPackageInfoClass(JCPackageDecl pd) {
2111 switch (pkginfoOpt) {
2112 case ALWAYS:
2113 return true;
2114 case LEGACY:
2115 return pd.getAnnotations().nonEmpty();
2116 case NONEMPTY:
2117 for (Attribute.Compound a :
2118 pd.packge.getDeclarationAttributes()) {
2119 Attribute.RetentionPolicy p = types.getRetention(a);
2120 if (p != Attribute.RetentionPolicy.SOURCE)
2121 return true;
2122 }
2123 return false;
2124 }
2125 throw new AssertionError();
2126 }
2127
2128 public void visitModuleDef(JCModuleDecl tree) {
2129 ModuleSymbol msym = tree.sym;
2130 ClassSymbol c = msym.module_info;
2131 c.setAttributes(msym);
2132 c.flags_field |= Flags.MODULE;
2133 createInfoClass(List.nil(), tree.sym.module_info);
2134 }
2135
2136 private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) {
2137 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2138 JCClassDecl infoClass =
2139 make.ClassDef(make.Modifiers(flags, annots),
2140 c.name, List.nil(),
2141 null, List.nil(), List.nil());
2142 infoClass.sym = c;
2143 translated.append(infoClass);
2144 }
2145
2146 public void visitClassDef(JCClassDecl tree) {
2147 Env<AttrContext> prevEnv = attrEnv;
2148 ClassSymbol currentClassPrev = currentClass;
2149 MethodSymbol currentMethodSymPrev = currentMethodSym;
2150
2151 currentClass = tree.sym;
2152 currentMethodSym = null;
2153 attrEnv = typeEnvs.remove(currentClass);
2154 if (attrEnv == null)
2155 attrEnv = prevEnv;
2156
2157 classdefs.put(currentClass, tree);
2158
2159 Map<Symbol, Symbol> prevProxies = proxies;
2160 proxies = new HashMap<>(proxies);
2161 List<VarSymbol> prevOuterThisStack = outerThisStack;
2162
2163 // If this is an enum definition
2164 if ((tree.mods.flags & ENUM) != 0 &&
2165 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0)
2166 visitEnumDef(tree);
2167
2168 if ((tree.mods.flags & RECORD) != 0) {
2169 visitRecordDef(tree);
2170 }
2171
2172 // If this is a nested class, define a this$n field for
2173 // it and add to proxies.
2174 JCVariableDecl otdef = null;
2175 if (currentClass.hasOuterInstance())
2176 otdef = outerThisDef(tree.pos, currentClass);
2177
2178 // If this is a local class, define proxies for all its free variables.
2179 List<JCVariableDecl> fvdefs = freevarDefs(
2180 tree.pos, freevars(currentClass), currentClass);
2181
2182 // Recursively translate superclass, interfaces.
2183 tree.extending = translate(tree.extending);
2184 tree.implementing = translate(tree.implementing);
2185
2186 if (currentClass.isDirectlyOrIndirectlyLocal()) {
2187 ClassSymbol encl = currentClass.owner.enclClass();
2188 if (encl.trans_local == null) {
2189 encl.trans_local = List.nil();
2190 }
2191 encl.trans_local = encl.trans_local.prepend(currentClass);
2192 }
2193
2194 // Recursively translate members, taking into account that new members
2195 // might be created during the translation and prepended to the member
2196 // list `tree.defs'.
2197 List<JCTree> seen = List.nil();
2198 while (tree.defs != seen) {
2199 List<JCTree> unseen = tree.defs;
2200 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) {
2201 JCTree outermostMemberDefPrev = outermostMemberDef;
2202 if (outermostMemberDefPrev == null) outermostMemberDef = l.head;
2203 l.head = translate(l.head);
2204 outermostMemberDef = outermostMemberDefPrev;
2205 }
2206 seen = unseen;
2207 }
2208
2209 // Convert a protected modifier to public, mask static modifier.
2210 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC;
2211 tree.mods.flags &= ClassFlags;
2212
2213 // Convert name to flat representation, replacing '.' by '$'.
2214 tree.name = Convert.shortName(currentClass.flatName());
2215
2216 // Add free variables proxy definitions to class.
2217
2218 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) {
2219 tree.defs = tree.defs.prepend(l.head);
2220 enterSynthetic(tree.pos(), l.head.sym, currentClass.members());
2221 }
2222 // If this$n was accessed, add the field definition and prepend
2223 // initializer code to any super() invocation to initialize it
2224 // otherwise prepend enclosing instance null check code if required
2225 emitOuter:
2226 if (currentClass.hasOuterInstance()) {
2227 boolean storesThis = shouldEmitOuterThis(currentClass);
2228 if (storesThis) {
2229 tree.defs = tree.defs.prepend(otdef);
2230 enterSynthetic(tree.pos(), otdef.sym, currentClass.members());
2231 } else if (!nullCheckOuterThis) {
2232 break emitOuter;
2233 }
2234
2235 for (JCTree def : tree.defs) {
2236 if (TreeInfo.isConstructor(def)) {
2237 JCMethodDecl mdef = (JCMethodDecl)def;
2238 if (TreeInfo.hasConstructorCall(mdef, names._super)) {
2239 List<JCStatement> initializer = List.of(initOuterThis(mdef.body.pos, mdef.params.head.sym, storesThis)) ;
2240 TreeInfo.mapSuperCalls(mdef.body, supercall -> make.Block(0, initializer.append(supercall)));
2241 }
2242 }
2243 }
2244 }
2245
2246 proxies = prevProxies;
2247 outerThisStack = prevOuterThisStack;
2248
2249 // Append translated tree to `translated' queue.
2250 translated.append(tree);
2251
2252 attrEnv = prevEnv;
2253 currentClass = currentClassPrev;
2254 currentMethodSym = currentMethodSymPrev;
2255
2256 // Return empty block {} as a placeholder for an inner class.
2257 result = make_at(tree.pos()).Block(SYNTHETIC, List.nil());
2258 }
2259
2260 private boolean shouldEmitOuterThis(ClassSymbol sym) {
2261 if (!optimizeOuterThis) {
2262 // Optimization is disabled
2263 return true;
2264 }
2265 if ((outerThisStack.head.flags_field & NOOUTERTHIS) == 0) {
2266 // Enclosing instance field is used
2267 return true;
2268 }
2269 if (rs.isSerializable(sym.type)) {
2270 // Class is serializable
2271 return true;
2272 }
2273 return false;
2274 }
2275
2276 List<JCTree> generateMandatedAccessors(JCClassDecl tree) {
2277 List<JCVariableDecl> fields = TreeInfo.recordFields(tree);
2278 return tree.sym.getRecordComponents().stream()
2279 .filter(rc -> (rc.accessor.flags() & Flags.GENERATED_MEMBER) != 0)
2280 .map(rc -> {
2281 // we need to return the field not the record component
2282 JCVariableDecl field = fields.stream().filter(f -> f.name == rc.name).findAny().get();
2283 make_at(tree.pos());
2284 return make.MethodDef(rc.accessor, make.Block(0,
2285 List.of(make.Return(make.Ident(field)))));
2286 }).collect(List.collector());
2287 }
2288
2289 /** Translate an enum class. */
2290 private void visitEnumDef(JCClassDecl tree) {
2291 make_at(tree.pos());
2292
2293 // add the supertype, if needed
2294 if (tree.extending == null)
2295 tree.extending = make.Type(types.supertype(tree.type));
2296
2297 // classOfType adds a cache field to tree.defs
2298 JCExpression e_class = classOfType(tree.sym.type, tree.pos()).
2299 setType(types.erasure(syms.classType));
2300
2301 // process each enumeration constant, adding implicit constructor parameters
2302 int nextOrdinal = 0;
2303 ListBuffer<JCExpression> values = new ListBuffer<>();
2304 ListBuffer<JCTree> enumDefs = new ListBuffer<>();
2305 ListBuffer<JCTree> otherDefs = new ListBuffer<>();
2306 for (List<JCTree> defs = tree.defs;
2307 defs.nonEmpty();
2308 defs=defs.tail) {
2309 if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
2310 JCVariableDecl var = (JCVariableDecl)defs.head;
2311 visitEnumConstantDef(var, nextOrdinal++);
2312 values.append(make.QualIdent(var.sym));
2313 enumDefs.append(var);
2314 } else {
2315 otherDefs.append(defs.head);
2316 }
2317 }
2318
2319 // synthetic private static T[] $values() { return new T[] { a, b, c }; }
2320 // synthetic private static final T[] $VALUES = $values();
2321 Name valuesName = syntheticName(tree, "VALUES");
2322 Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass);
2323 VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC,
2324 valuesName,
2325 arrayType,
2326 tree.type.tsym);
2327 JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)),
2328 List.nil(),
2329 values.toList());
2330 newArray.type = arrayType;
2331
2332 MethodSymbol valuesMethod = new MethodSymbol(PRIVATE|STATIC|SYNTHETIC,
2333 syntheticName(tree, "values"),
2334 new MethodType(List.nil(), arrayType, List.nil(), tree.type.tsym),
2335 tree.type.tsym);
2336 enumDefs.append(make.MethodDef(valuesMethod, make.Block(0, List.of(make.Return(newArray)))));
2337 tree.sym.members().enter(valuesMethod);
2338
2339 enumDefs.append(make.VarDef(valuesVar, make.App(make.QualIdent(valuesMethod))));
2340 tree.sym.members().enter(valuesVar);
2341
2342 MethodSymbol valuesSym = lookupMethod(tree.pos(), names.values,
2343 tree.type, List.nil());
2344 List<JCStatement> valuesBody;
2345 if (useClone()) {
2346 // return (T[]) $VALUES.clone();
2347 JCTypeCast valuesResult =
2348 make.TypeCast(valuesSym.type.getReturnType(),
2349 make.App(make.Select(make.Ident(valuesVar),
2350 syms.arrayCloneMethod)));
2351 valuesBody = List.of(make.Return(valuesResult));
2352 } else {
2353 // template: T[] $result = new T[$values.length];
2354 Name resultName = syntheticName(tree, "result");
2355 VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC,
2356 resultName,
2357 arrayType,
2358 valuesSym);
2359 JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)),
2360 List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)),
2361 null);
2362 resultArray.type = arrayType;
2363 JCVariableDecl decl = make.VarDef(resultVar, resultArray);
2364
2365 // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length);
2366 if (systemArraycopyMethod == null) {
2367 systemArraycopyMethod =
2368 new MethodSymbol(PUBLIC | STATIC,
2369 names.fromString("arraycopy"),
2370 new MethodType(List.of(syms.objectType,
2371 syms.intType,
2372 syms.objectType,
2373 syms.intType,
2374 syms.intType),
2375 syms.voidType,
2376 List.nil(),
2377 syms.methodClass),
2378 syms.systemType.tsym);
2379 }
2380 JCStatement copy =
2381 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym),
2382 systemArraycopyMethod),
2383 List.of(make.Ident(valuesVar), make.Literal(0),
2384 make.Ident(resultVar), make.Literal(0),
2385 make.Select(make.Ident(valuesVar), syms.lengthVar))));
2386
2387 // template: return $result;
2388 JCStatement ret = make.Return(make.Ident(resultVar));
2389 valuesBody = List.of(decl, copy, ret);
2390 }
2391
2392 JCMethodDecl valuesDef =
2393 make.MethodDef(valuesSym, make.Block(0, valuesBody));
2394
2395 enumDefs.append(valuesDef);
2396
2397 if (debugLower)
2398 System.err.println(tree.sym + ".valuesDef = " + valuesDef);
2399
2400 /** The template for the following code is:
2401 *
2402 * public static E valueOf(String name) {
2403 * return (E)Enum.valueOf(E.class, name);
2404 * }
2405 *
2406 * where E is tree.sym
2407 */
2408 MethodSymbol valueOfSym = lookupMethod(tree.pos(),
2409 names.valueOf,
2410 tree.sym.type,
2411 List.of(syms.stringType));
2412 Assert.check((valueOfSym.flags() & STATIC) != 0);
2413 VarSymbol nameArgSym = valueOfSym.params.head;
2414 JCIdent nameVal = make.Ident(nameArgSym);
2415 JCStatement enum_ValueOf =
2416 make.Return(make.TypeCast(tree.sym.type,
2417 makeCall(make.Ident(syms.enumSym),
2418 names.valueOf,
2419 List.of(e_class, nameVal))));
2420 JCMethodDecl valueOf = make.MethodDef(valueOfSym,
2421 make.Block(0, List.of(enum_ValueOf)));
2422 nameVal.sym = valueOf.params.head.sym;
2423 if (debugLower)
2424 System.err.println(tree.sym + ".valueOf = " + valueOf);
2425 enumDefs.append(valueOf);
2426
2427 enumDefs.appendList(otherDefs.toList());
2428 tree.defs = enumDefs.toList();
2429 }
2430 // where
2431 private MethodSymbol systemArraycopyMethod;
2432 private boolean useClone() {
2433 try {
2434 return syms.objectType.tsym.members().findFirst(names.clone) != null;
2435 }
2436 catch (CompletionFailure e) {
2437 return false;
2438 }
2439 }
2440
2441 private Name syntheticName(JCClassDecl tree, String baseName) {
2442 Name valuesName = names.fromString(target.syntheticNameChar() + baseName);
2443 while (tree.sym.members().findFirst(valuesName) != null) // avoid name clash
2444 valuesName = names.fromString(valuesName + "" + target.syntheticNameChar());
2445 return valuesName;
2446 }
2447
2448 /** Translate an enumeration constant and its initializer. */
2449 private void visitEnumConstantDef(JCVariableDecl var, int ordinal) {
2450 JCNewClass varDef = (JCNewClass)var.init;
2451 varDef.args = varDef.args.
2452 prepend(makeLit(syms.intType, ordinal)).
2453 prepend(makeLit(syms.stringType, var.name.toString()));
2454 }
2455
2456 private List<VarSymbol> recordVars(Type t) {
2457 List<VarSymbol> vars = List.nil();
2458 while (!t.hasTag(NONE)) {
2459 if (t.hasTag(CLASS)) {
2460 for (Symbol s : t.tsym.members().getSymbols(s -> s.kind == VAR && (s.flags() & RECORD) != 0)) {
2461 vars = vars.prepend((VarSymbol)s);
2462 }
2463 }
2464 t = types.supertype(t);
2465 }
2466 return vars;
2467 }
2468
2469 /** Translate a record. */
2470 private void visitRecordDef(JCClassDecl tree) {
2471 make_at(tree.pos());
2472 List<VarSymbol> vars = recordVars(tree.type);
2473 MethodHandleSymbol[] getterMethHandles = new MethodHandleSymbol[vars.size()];
2474 int index = 0;
2475 for (VarSymbol var : vars) {
2476 if (var.owner != tree.sym) {
2477 var = new VarSymbol(var.flags_field, var.name, var.type, tree.sym);
2478 }
2479 getterMethHandles[index] = var.asMethodHandle(true);
2480 index++;
2481 }
2482
2483 tree.defs = tree.defs.appendList(generateMandatedAccessors(tree));
2484 tree.defs = tree.defs.appendList(List.of(
2485 generateRecordMethod(tree, names.toString, vars, getterMethHandles),
2486 generateRecordMethod(tree, names.hashCode, vars, getterMethHandles),
2487 generateRecordMethod(tree, names.equals, vars, getterMethHandles)
2488 ));
2489 }
2490
2491 JCTree generateRecordMethod(JCClassDecl tree, Name name, List<VarSymbol> vars, MethodHandleSymbol[] getterMethHandles) {
2492 make_at(tree.pos());
2493 boolean isEquals = name == names.equals;
2494 MethodSymbol msym = lookupMethod(tree.pos(),
2495 name,
2496 tree.sym.type,
2497 isEquals ? List.of(syms.objectType) : List.nil());
2498 // compiler generated methods have the record flag set, user defined ones dont
2499 if ((msym.flags() & RECORD) != 0) {
2500 /* class java.lang.runtime.ObjectMethods provides a common bootstrap that provides a customized implementation
2501 * for methods: toString, hashCode and equals. Here we just need to generate and indy call to:
2502 * java.lang.runtime.ObjectMethods::bootstrap and provide: the record class, the record component names and
2503 * the accessors.
2504 */
2505 Name bootstrapName = names.bootstrap;
2506 LoadableConstant[] staticArgsValues = new LoadableConstant[2 + getterMethHandles.length];
2507 staticArgsValues[0] = (ClassType)tree.sym.type;
2508 String concatNames = vars.stream()
2509 .map(v -> v.name)
2510 .collect(Collectors.joining(";", "", ""));
2511 staticArgsValues[1] = LoadableConstant.String(concatNames);
2512 int index = 2;
2513 for (MethodHandleSymbol mho : getterMethHandles) {
2514 staticArgsValues[index] = mho;
2515 index++;
2516 }
2517
2518 List<Type> staticArgTypes = List.of(syms.classType,
2519 syms.stringType,
2520 new ArrayType(syms.methodHandleType, syms.arrayClass));
2521
2522 JCFieldAccess qualifier = makeIndyQualifier(syms.objectMethodsType, tree, msym,
2523 List.of(syms.methodHandleLookupType,
2524 syms.stringType,
2525 syms.typeDescriptorType).appendList(staticArgTypes),
2526 staticArgsValues, bootstrapName, name, false);
2527
2528 VarSymbol _this = new VarSymbol(SYNTHETIC, names._this, tree.sym.type, tree.sym);
2529
2530 JCMethodInvocation proxyCall;
2531 if (!isEquals) {
2532 proxyCall = make.Apply(List.nil(), qualifier, List.of(make.Ident(_this)));
2533 } else {
2534 VarSymbol o = msym.params.head;
2535 o.adr = 0;
2536 proxyCall = make.Apply(List.nil(), qualifier, List.of(make.Ident(_this), make.Ident(o)));
2537 }
2538 proxyCall.type = qualifier.type;
2539 return make.MethodDef(msym, make.Block(0, List.of(make.Return(proxyCall))));
2540 } else {
2541 return make.Block(SYNTHETIC, List.nil());
2542 }
2543 }
2544
2545 private String argsTypeSig(List<Type> typeList) {
2546 LowerSignatureGenerator sg = new LowerSignatureGenerator();
2547 sg.assembleSig(typeList);
2548 return sg.toString();
2549 }
2550
2551 /**
2552 * Signature Generation
2553 */
2554 private class LowerSignatureGenerator extends Types.SignatureGenerator {
2555
2556 /**
2557 * An output buffer for type signatures.
2558 */
2559 StringBuilder sb = new StringBuilder();
2560
2561 LowerSignatureGenerator() {
2562 types.super();
2563 }
2564
2565 @Override
2566 protected void append(char ch) {
2567 sb.append(ch);
2568 }
2569
2570 @Override
2571 protected void append(byte[] ba) {
2572 sb.append(new String(ba));
2573 }
2574
2575 @Override
2576 protected void append(Name name) {
2577 sb.append(name.toString());
2578 }
2579
2580 @Override
2581 public String toString() {
2582 return sb.toString();
2583 }
2584 }
2585
2586 /**
2587 * Creates an indy qualifier, helpful to be part of an indy invocation
2588 * @param site the site
2589 * @param tree a class declaration tree
2590 * @param msym the method symbol
2591 * @param staticArgTypes the static argument types
2592 * @param staticArgValues the static argument values
2593 * @param bootstrapName the bootstrap name to look for
2594 * @param argName normally bootstraps receives a method name as second argument, if you want that name
2595 * to be different to that of the bootstrap name pass a different name here
2596 * @param isStatic is it static or not
2597 * @return a field access tree
2598 */
2599 JCFieldAccess makeIndyQualifier(
2600 Type site,
2601 JCClassDecl tree,
2602 MethodSymbol msym,
2603 List<Type> staticArgTypes,
2604 LoadableConstant[] staticArgValues,
2605 Name bootstrapName,
2606 Name argName,
2607 boolean isStatic) {
2608 MethodSymbol bsm = rs.resolveInternalMethod(tree.pos(), attrEnv, site,
2609 bootstrapName, staticArgTypes, List.nil());
2610
2611 MethodType indyType = msym.type.asMethodType();
2612 indyType = new MethodType(
2613 isStatic ? List.nil() : indyType.argtypes.prepend(tree.sym.type),
2614 indyType.restype,
2615 indyType.thrown,
2616 syms.methodClass
2617 );
2618 DynamicMethodSymbol dynSym = new DynamicMethodSymbol(argName,
2619 syms.noSymbol,
2620 bsm.asHandle(),
2621 indyType,
2622 staticArgValues);
2623 JCFieldAccess qualifier = make.Select(make.QualIdent(site.tsym), argName);
2624 qualifier.sym = dynSym;
2625 qualifier.type = msym.type.asMethodType().restype;
2626 return qualifier;
2627 }
2628
2629 public void visitMethodDef(JCMethodDecl tree) {
2630 if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) {
2631 // Add "String $enum$name, int $enum$ordinal" to the beginning of the
2632 // argument list for each constructor of an enum.
2633 JCVariableDecl nameParam = make_at(tree.pos()).
2634 Param(names.fromString(target.syntheticNameChar() +
2635 "enum" + target.syntheticNameChar() + "name"),
2636 syms.stringType, tree.sym);
2637 nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC;
2638 JCVariableDecl ordParam = make.
2639 Param(names.fromString(target.syntheticNameChar() +
2640 "enum" + target.syntheticNameChar() +
2641 "ordinal"),
2642 syms.intType, tree.sym);
2643 ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC;
2644
2645 MethodSymbol m = tree.sym;
2646 tree.params = tree.params.prepend(ordParam).prepend(nameParam);
2647
2648 m.extraParams = m.extraParams.prepend(ordParam.sym);
2649 m.extraParams = m.extraParams.prepend(nameParam.sym);
2650 Type olderasure = m.erasure(types);
2651 m.erasure_field = new MethodType(
2652 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType),
2653 olderasure.getReturnType(),
2654 olderasure.getThrownTypes(),
2655 syms.methodClass);
2656 }
2657
2658 Type prevRestype = currentRestype;
2659 JCMethodDecl prevMethodDef = currentMethodDef;
2660 MethodSymbol prevMethodSym = currentMethodSym;
2661 int prevVariableIndex = variableIndex;
2662 try {
2663 currentRestype = types.erasure(tree.type.getReturnType());
2664 currentMethodDef = tree;
2665 currentMethodSym = tree.sym;
2666 variableIndex = 0;
2667 visitMethodDefInternal(tree);
2668 } finally {
2669 currentRestype = prevRestype;
2670 currentMethodDef = prevMethodDef;
2671 currentMethodSym = prevMethodSym;
2672 variableIndex = prevVariableIndex;
2673 }
2674 }
2675
2676 private void visitMethodDefInternal(JCMethodDecl tree) {
2677 if (tree.name == names.init &&
2678 !currentClass.isStatic() &&
2679 (currentClass.isInner() || currentClass.isDirectlyOrIndirectlyLocal())) {
2680 // We are seeing a constructor of an inner class.
2681 MethodSymbol m = tree.sym;
2682
2683 // Push a new proxy scope for constructor parameters.
2684 // and create definitions for any this$n and proxy parameters.
2685 Map<Symbol, Symbol> prevProxies = proxies;
2686 proxies = new HashMap<>(proxies);
2687 List<VarSymbol> prevOuterThisStack = outerThisStack;
2688 List<VarSymbol> fvs = freevars(currentClass);
2689 JCVariableDecl otdef = null;
2690 if (currentClass.hasOuterInstance())
2691 otdef = outerThisDef(tree.pos, m);
2692 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER);
2693
2694 // Recursively translate result type, parameters and thrown list.
2695 tree.restype = translate(tree.restype);
2696 tree.params = translateVarDefs(tree.params);
2697 tree.thrown = translate(tree.thrown);
2698
2699 // when compiling stubs, don't process body
2700 if (tree.body == null) {
2701 result = tree;
2702 return;
2703 }
2704
2705 // Add this$n (if needed) in front of and free variables behind
2706 // constructor parameter list.
2707 tree.params = tree.params.appendList(fvdefs);
2708 if (currentClass.hasOuterInstance()) {
2709 tree.params = tree.params.prepend(otdef);
2710 }
2711
2712 // Determine whether this constructor has a super() invocation
2713 boolean invokesSuper = TreeInfo.hasConstructorCall(tree, names._super);
2714
2715 // Create initializers for this$n and proxies
2716 ListBuffer<JCStatement> added = new ListBuffer<>();
2717 if (fvs.nonEmpty()) {
2718 List<Type> addedargtypes = List.nil();
2719 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
2720 m.capturedLocals =
2721 m.capturedLocals.prepend((VarSymbol)
2722 (proxies.get(l.head)));
2723 if (invokesSuper) {
2724 added = added.prepend(
2725 initField(tree.body.pos, proxies.get(l.head), prevProxies.get(l.head)));
2726 }
2727 addedargtypes = addedargtypes.prepend(l.head.erasure(types));
2728 }
2729 Type olderasure = m.erasure(types);
2730 m.erasure_field = new MethodType(
2731 olderasure.getParameterTypes().appendList(addedargtypes),
2732 olderasure.getReturnType(),
2733 olderasure.getThrownTypes(),
2734 syms.methodClass);
2735 }
2736
2737 // Recursively translate existing local statements
2738 tree.body.stats = translate(tree.body.stats);
2739
2740 // Prepend initializers in front of super() call
2741 if (added.nonEmpty()) {
2742 List<JCStatement> initializers = added.toList();
2743 TreeInfo.mapSuperCalls(tree.body, supercall -> make.Block(0, initializers.append(supercall)));
2744 }
2745
2746 // pop local variables from proxy stack
2747 proxies = prevProxies;
2748
2749 outerThisStack = prevOuterThisStack;
2750 } else {
2751 super.visitMethodDef(tree);
2752 }
2753 if (tree.name == names.init && ((tree.sym.flags_field & Flags.COMPACT_RECORD_CONSTRUCTOR) != 0 ||
2754 (tree.sym.flags_field & (GENERATEDCONSTR | RECORD)) == (GENERATEDCONSTR | RECORD))) {
2755 // lets find out if there is any field waiting to be initialized
2756 ListBuffer<VarSymbol> fields = new ListBuffer<>();
2757 for (Symbol sym : currentClass.getEnclosedElements()) {
2758 if (sym.kind == Kinds.Kind.VAR && ((sym.flags() & RECORD) != 0))
2759 fields.append((VarSymbol) sym);
2760 }
2761 for (VarSymbol field: fields) {
2762 if ((field.flags_field & Flags.UNINITIALIZED_FIELD) != 0) {
2763 VarSymbol param = tree.params.stream().filter(p -> p.name == field.name).findFirst().get().sym;
2764 make.at(tree.pos);
2765 tree.body.stats = tree.body.stats.append(
2766 make.Exec(
2767 make.Assign(
2768 make.Select(make.This(field.owner.erasure(types)), field),
2769 make.Ident(param)).setType(field.erasure(types))));
2770 // we don't need the flag at the field anymore
2771 field.flags_field &= ~Flags.UNINITIALIZED_FIELD;
2772 }
2773 }
2774 }
2775 result = tree;
2776 }
2777
2778 public void visitTypeCast(JCTypeCast tree) {
2779 tree.clazz = translate(tree.clazz);
2780 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive())
2781 tree.expr = translate(tree.expr, tree.type);
2782 else
2783 tree.expr = translate(tree.expr);
2784 result = tree;
2785 }
2786
2787 /**
2788 * All the exactness checks between primitive types that require a run-time
2789 * check are in {@code java.lang.runtime.ExactConversionsSupport}. Those methods
2790 * are in the form {@code ExactConversionsSupport.is<S>To<T>Exact} where both
2791 * {@code S} and {@code T} are primitive types and correspond to the runtime
2792 * action that will be executed to check whether a certain value (that is passed
2793 * as a parameter) can be converted to {@code T} without loss of information.
2794 *
2795 * Rewrite {@code instanceof if expr : Object} and Type is primitive type:
2796 *
2797 * {@snippet :
2798 * Object v = ...
2799 * if (v instanceof float)
2800 * =>
2801 * if (let tmp$123 = v; tmp$123 instanceof Float)
2802 * }
2803 *
2804 * Rewrite {@code instanceof if expr : wrapper reference type}
2805 *
2806 * {@snippet :
2807 * Integer v = ...
2808 * if (v instanceof float)
2809 * =>
2810 * if (let tmp$123 = v; tmp$123 != null && ExactConversionsSupport.intToFloatExact(tmp$123.intValue()))
2811 * }
2812 *
2813 * Rewrite {@code instanceof if expr : primitive}
2814 *
2815 * {@snippet :
2816 * int v = ...
2817 * if (v instanceof float)
2818 * =>
2819 * if (let tmp$123 = v; ExactConversionsSupport.intToFloatExact(tmp$123))
2820 * }
2821 *
2822 * More rewritings:
2823 * <ul>
2824 * <li>If the {@code instanceof} check is unconditionally exact rewrite to true.</li>
2825 * <li>If expression type is {@code Byte}, {@code Short}, {@code Integer}, ..., an
2826 * unboxing conversion followed by a widening primitive conversion.</li>
2827 * <li>If expression type is a supertype: {@code Number}, a narrowing reference
2828 * conversion followed by an unboxing conversion.</li>
2829 * </ul>
2830 */
2831 public void visitTypeTest(JCInstanceOf tree) {
2832 if (tree.expr.type.isPrimitive() || tree.pattern.type.isPrimitive()) {
2833 JCStatement prefixStatement;
2834 JCExpression exactnessCheck;
2835 JCExpression instanceOfExpr = translate(tree.expr);
2836
2837 if (types.isUnconditionallyExactTypeBased(tree.expr.type, tree.pattern.type)) {
2838 // instanceOfExpr; true
2839 prefixStatement = make.Exec(instanceOfExpr);
2840 exactnessCheck = make.Literal(BOOLEAN, 1).setType(syms.booleanType.constType(1));
2841 } else if (tree.expr.type.isPrimitive()) {
2842 // ExactConversionSupport.isXxxExact(instanceOfExpr)
2843 prefixStatement = null;
2844 exactnessCheck = getExactnessCheck(tree, instanceOfExpr);
2845 } else if (tree.expr.type.isReference()) {
2846 if (types.isUnconditionallyExactTypeBased(types.unboxedType(tree.expr.type), tree.pattern.type)) {
2847 // instanceOfExpr != null
2848 prefixStatement = null;
2849 exactnessCheck = makeBinary(NE, instanceOfExpr, makeNull());
2850 } else {
2851 // We read the result of instanceOfExpr, so create variable
2852 VarSymbol dollar_s = new VarSymbol(FINAL | SYNTHETIC,
2853 names.fromString("tmp" + variableIndex++ + this.target.syntheticNameChar()),
2854 types.erasure(tree.expr.type),
2855 currentMethodSym);
2856 prefixStatement = make.at(tree.pos())
2857 .VarDef(dollar_s, instanceOfExpr);
2858
2859 JCExpression nullCheck =
2860 makeBinary(NE,
2861 make.Ident(dollar_s),
2862 makeNull());
2863
2864 if (types.unboxedType(tree.expr.type).isPrimitive()) {
2865 exactnessCheck =
2866 makeBinary(AND,
2867 nullCheck,
2868 getExactnessCheck(tree, boxIfNeeded(make.Ident(dollar_s), types.unboxedType(tree.expr.type))));
2869 } else {
2870 exactnessCheck =
2871 makeBinary(AND,
2872 nullCheck,
2873 make.at(tree.pos())
2874 .TypeTest(make.Ident(dollar_s), make.Type(types.boxedClass(tree.pattern.type).type))
2875 .setType(syms.booleanType));
2876 }
2877 }
2878 } else {
2879 throw Assert.error("Non primitive or reference type: " + tree.expr.type);
2880 }
2881 result = (prefixStatement == null ? exactnessCheck : make.LetExpr(List.of(prefixStatement), exactnessCheck))
2882 .setType(syms.booleanType);
2883 } else {
2884 tree.expr = translate(tree.expr);
2885 tree.pattern = translate(tree.pattern);
2886 result = tree;
2887 }
2888 }
2889
2890 // TypePairs should be in sync with the corresponding record in SwitchBootstraps
2891 record TypePairs(TypeSymbol from, TypeSymbol to) {
2892 public static TypePairs of(Symtab syms, Type from, Type to) {
2893 if (from == syms.byteType || from == syms.shortType || from == syms.charType) {
2894 from = syms.intType;
2895 }
2896 return new TypePairs(from, to);
2897 }
2898
2899 public TypePairs(Type from, Type to) {
2900 this(from.tsym, to.tsym);
2901 }
2902
2903 public static HashMap<TypePairs, String> initialize(Symtab syms) {
2904 HashMap<TypePairs, String> typePairToName = new HashMap<>();
2905 typePairToName.put(new TypePairs(syms.byteType, syms.charType), "isIntToCharExact"); // redirected
2906 typePairToName.put(new TypePairs(syms.shortType, syms.byteType), "isIntToByteExact"); // redirected
2907 typePairToName.put(new TypePairs(syms.shortType, syms.charType), "isIntToCharExact"); // redirected
2908 typePairToName.put(new TypePairs(syms.charType, syms.byteType), "isIntToByteExact"); // redirected
2909 typePairToName.put(new TypePairs(syms.charType, syms.shortType), "isIntToShortExact"); // redirected
2910 typePairToName.put(new TypePairs(syms.intType, syms.byteType), "isIntToByteExact");
2911 typePairToName.put(new TypePairs(syms.intType, syms.shortType), "isIntToShortExact");
2912 typePairToName.put(new TypePairs(syms.intType, syms.charType), "isIntToCharExact");
2913 typePairToName.put(new TypePairs(syms.intType, syms.floatType), "isIntToFloatExact");
2914 typePairToName.put(new TypePairs(syms.longType, syms.byteType), "isLongToByteExact");
2915 typePairToName.put(new TypePairs(syms.longType, syms.shortType), "isLongToShortExact");
2916 typePairToName.put(new TypePairs(syms.longType, syms.charType), "isLongToCharExact");
2917 typePairToName.put(new TypePairs(syms.longType, syms.intType), "isLongToIntExact");
2918 typePairToName.put(new TypePairs(syms.longType, syms.floatType), "isLongToFloatExact");
2919 typePairToName.put(new TypePairs(syms.longType, syms.doubleType), "isLongToDoubleExact");
2920 typePairToName.put(new TypePairs(syms.floatType, syms.byteType), "isFloatToByteExact");
2921 typePairToName.put(new TypePairs(syms.floatType, syms.shortType), "isFloatToShortExact");
2922 typePairToName.put(new TypePairs(syms.floatType, syms.charType), "isFloatToCharExact");
2923 typePairToName.put(new TypePairs(syms.floatType, syms.intType), "isFloatToIntExact");
2924 typePairToName.put(new TypePairs(syms.floatType, syms.longType), "isFloatToLongExact");
2925 typePairToName.put(new TypePairs(syms.doubleType, syms.byteType), "isDoubleToByteExact");
2926 typePairToName.put(new TypePairs(syms.doubleType, syms.shortType), "isDoubleToShortExact");
2927 typePairToName.put(new TypePairs(syms.doubleType, syms.charType), "isDoubleToCharExact");
2928 typePairToName.put(new TypePairs(syms.doubleType, syms.intType), "isDoubleToIntExact");
2929 typePairToName.put(new TypePairs(syms.doubleType, syms.longType), "isDoubleToLongExact");
2930 typePairToName.put(new TypePairs(syms.doubleType, syms.floatType), "isDoubleToFloatExact");
2931 return typePairToName;
2932 }
2933 }
2934
2935 private JCExpression getExactnessCheck(JCInstanceOf tree, JCExpression argument) {
2936 TypePairs pair = TypePairs.of(syms, types.unboxedTypeOrType(tree.expr.type), tree.pattern.type);
2937
2938 Name exactnessFunction = names.fromString(typePairToName.get(pair));
2939
2940 // Resolve the exactness method
2941 Symbol ecsym = lookupMethod(tree.pos(),
2942 exactnessFunction,
2943 syms.exactConversionsSupportType,
2944 List.of(pair.from.type));
2945
2946 // Generate the method call ExactnessChecks.<exactness method>(<argument>);
2947 JCFieldAccess select = make.Select(
2948 make.QualIdent(syms.exactConversionsSupportType.tsym),
2949 exactnessFunction);
2950 select.sym = ecsym;
2951 select.setType(syms.booleanType);
2952
2953 JCExpression exactnessCheck = make.Apply(List.nil(),
2954 select,
2955 List.of(argument));
2956 exactnessCheck.setType(syms.booleanType);
2957 return exactnessCheck;
2958 }
2959
2960 public void visitNewClass(JCNewClass tree) {
2961 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
2962
2963 // Box arguments, if necessary
2964 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0;
2965 List<Type> argTypes = tree.constructor.type.getParameterTypes();
2966 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType);
2967 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement);
2968 tree.varargsElement = null;
2969
2970 // If created class is local, add free variables after
2971 // explicit constructor arguments.
2972 if (c.isDirectlyOrIndirectlyLocal() && !c.isStatic()) {
2973 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
2974 }
2975
2976 // If an access constructor is used, append null as a last argument.
2977 Symbol constructor = accessConstructor(tree.pos(), tree.constructor);
2978 if (constructor != tree.constructor) {
2979 tree.args = tree.args.append(makeNull());
2980 tree.constructor = constructor;
2981 }
2982
2983 // If created class has an outer instance, and new is qualified, pass
2984 // qualifier as first argument. If new is not qualified, pass the
2985 // correct outer instance as first argument.
2986 if (c.hasOuterInstance()) {
2987 JCExpression thisArg;
2988 if (tree.encl != null) {
2989 thisArg = attr.makeNullCheck(translate(tree.encl));
2990 thisArg.type = tree.encl.type;
2991 } else if (c.isDirectlyOrIndirectlyLocal()) {
2992 // local class
2993 thisArg = makeThis(tree.pos(), c.innermostAccessibleEnclosingClass());
2994 } else {
2995 // nested class
2996 thisArg = makeOwnerThis(tree.pos(), c, false);
2997 }
2998 tree.args = tree.args.prepend(thisArg);
2999 }
3000 tree.encl = null;
3001
3002 // If we have an anonymous class, create its flat version, rather
3003 // than the class or interface following new.
3004 if (tree.def != null) {
3005 translate(tree.def);
3006
3007 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym));
3008 tree.def = null;
3009 } else {
3010 tree.clazz = access(c, tree.clazz, enclOp, false);
3011 }
3012 result = tree;
3013 }
3014
3015 // Simplify conditionals with known constant controlling expressions.
3016 // This allows us to avoid generating supporting declarations for
3017 // the dead code, which will not be eliminated during code generation.
3018 // Note that Flow.isFalse and Flow.isTrue only return true
3019 // for constant expressions in the sense of JLS 15.27, which
3020 // are guaranteed to have no side-effects. More aggressive
3021 // constant propagation would require that we take care to
3022 // preserve possible side-effects in the condition expression.
3023
3024 // One common case is equality expressions involving a constant and null.
3025 // Since null is not a constant expression (because null cannot be
3026 // represented in the constant pool), equality checks involving null are
3027 // not captured by Flow.isTrue/isFalse.
3028 // Equality checks involving a constant and null, e.g.
3029 // "" == null
3030 // are safe to simplify as no side-effects can occur.
3031
3032 private boolean isTrue(JCTree exp) {
3033 if (exp.type.isTrue())
3034 return true;
3035 Boolean b = expValue(exp);
3036 return b == null ? false : b;
3037 }
3038 private boolean isFalse(JCTree exp) {
3039 if (exp.type.isFalse())
3040 return true;
3041 Boolean b = expValue(exp);
3042 return b == null ? false : !b;
3043 }
3044 /* look for (in)equality relations involving null.
3045 * return true - if expression is always true
3046 * false - if expression is always false
3047 * null - if expression cannot be eliminated
3048 */
3049 private Boolean expValue(JCTree exp) {
3050 while (exp.hasTag(PARENS))
3051 exp = ((JCParens)exp).expr;
3052
3053 boolean eq;
3054 switch (exp.getTag()) {
3055 case EQ: eq = true; break;
3056 case NE: eq = false; break;
3057 default:
3058 return null;
3059 }
3060
3061 // we have a JCBinary(EQ|NE)
3062 // check if we have two literals (constants or null)
3063 JCBinary b = (JCBinary)exp;
3064 if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs);
3065 if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs);
3066 return null;
3067 }
3068 private Boolean expValueIsNull(boolean eq, JCTree t) {
3069 if (t.type.hasTag(BOT)) return Boolean.valueOf(eq);
3070 if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq);
3071 return null;
3072 }
3073
3074 /** Visitor method for conditional expressions.
3075 */
3076 @Override
3077 public void visitConditional(JCConditional tree) {
3078 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
3079 if (isTrue(cond) && noClassDefIn(tree.falsepart)) {
3080 result = convert(translate(tree.truepart, tree.type), tree.type);
3081 addPrunedInfo(cond);
3082 } else if (isFalse(cond) && noClassDefIn(tree.truepart)) {
3083 result = convert(translate(tree.falsepart, tree.type), tree.type);
3084 addPrunedInfo(cond);
3085 } else {
3086 // Condition is not a compile-time constant.
3087 tree.truepart = translate(tree.truepart, tree.type);
3088 tree.falsepart = translate(tree.falsepart, tree.type);
3089 result = tree;
3090 }
3091 }
3092 //where
3093 private JCExpression convert(JCExpression tree, Type pt) {
3094 if (tree.type == pt || tree.type.hasTag(BOT))
3095 return tree;
3096 JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree);
3097 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt)
3098 : pt;
3099 return result;
3100 }
3101
3102 /** Visitor method for if statements.
3103 */
3104 public void visitIf(JCIf tree) {
3105 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
3106 if (isTrue(cond) && noClassDefIn(tree.elsepart)) {
3107 result = translate(tree.thenpart);
3108 addPrunedInfo(cond);
3109 } else if (isFalse(cond) && noClassDefIn(tree.thenpart)) {
3110 if (tree.elsepart != null) {
3111 result = translate(tree.elsepart);
3112 } else {
3113 result = make.Skip();
3114 }
3115 addPrunedInfo(cond);
3116 } else {
3117 // Condition is not a compile-time constant.
3118 tree.thenpart = translate(tree.thenpart);
3119 tree.elsepart = translate(tree.elsepart);
3120 result = tree;
3121 }
3122 }
3123
3124 /** Visitor method for assert statements. Translate them away.
3125 */
3126 public void visitAssert(JCAssert tree) {
3127 tree.cond = translate(tree.cond, syms.booleanType);
3128 if (!tree.cond.type.isTrue()) {
3129 JCExpression cond = assertFlagTest(tree.pos());
3130 List<JCExpression> exnArgs = (tree.detail == null) ?
3131 List.nil() : List.of(translate(tree.detail));
3132 if (!tree.cond.type.isFalse()) {
3133 cond = makeBinary
3134 (AND,
3135 cond,
3136 makeUnary(NOT, tree.cond));
3137 }
3138 result =
3139 make.If(cond,
3140 make_at(tree).
3141 Throw(makeNewClass(syms.assertionErrorType, exnArgs)),
3142 null);
3143 } else {
3144 result = make.Skip();
3145 }
3146 }
3147
3148 public void visitApply(JCMethodInvocation tree) {
3149 Symbol meth = TreeInfo.symbol(tree.meth);
3150 List<Type> argtypes = meth.type.getParameterTypes();
3151 if (meth.name == names.init && meth.owner == syms.enumSym)
3152 argtypes = argtypes.tail.tail;
3153 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement);
3154 tree.varargsElement = null;
3155 Name methName = TreeInfo.name(tree.meth);
3156 if (meth.name==names.init) {
3157 // We are seeing a this(...) or super(...) constructor call.
3158 // If an access constructor is used, append null as a last argument.
3159 Symbol constructor = accessConstructor(tree.pos(), meth);
3160 if (constructor != meth) {
3161 tree.args = tree.args.append(makeNull());
3162 TreeInfo.setSymbol(tree.meth, constructor);
3163 }
3164
3165 // If we are calling a constructor of a local class, add
3166 // free variables after explicit constructor arguments.
3167 ClassSymbol c = (ClassSymbol)constructor.owner;
3168 if (c.isDirectlyOrIndirectlyLocal() && !c.isStatic()) {
3169 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
3170 }
3171
3172 // If we are calling a constructor of an enum class, pass
3173 // along the name and ordinal arguments
3174 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) {
3175 List<JCVariableDecl> params = currentMethodDef.params;
3176 if (currentMethodSym.owner.hasOuterInstance())
3177 params = params.tail; // drop this$n
3178 tree.args = tree.args
3179 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal
3180 .prepend(make.Ident(params.head.sym)); // name
3181 }
3182
3183 // If we are calling a constructor of a class with an outer
3184 // instance, and the call
3185 // is qualified, pass qualifier as first argument in front of
3186 // the explicit constructor arguments. If the call
3187 // is not qualified, pass the correct outer instance as
3188 // first argument. If we are a static class, there is no
3189 // such outer instance, so generate an error.
3190 if (c.hasOuterInstance()) {
3191 JCExpression thisArg;
3192 if (tree.meth.hasTag(SELECT)) {
3193 thisArg = attr.
3194 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected));
3195 tree.meth = make.Ident(constructor);
3196 ((JCIdent) tree.meth).name = methName;
3197 } else if (c.isDirectlyOrIndirectlyLocal() || methName == names._this){
3198 // local class or this() call
3199 thisArg = makeThis(tree.meth.pos(), c.innermostAccessibleEnclosingClass());
3200 } else if (currentClass.isStatic()) {
3201 // super() call from static nested class - invalid
3202 log.error(tree.pos(),
3203 Errors.NoEnclInstanceOfTypeInScope(c.type.getEnclosingType().tsym));
3204 thisArg = make.Literal(BOT, null).setType(syms.botType);
3205 } else {
3206 // super() call of nested class - never pick 'this'
3207 thisArg = makeOwnerThisN(tree.meth.pos(), c, false);
3208 }
3209 tree.args = tree.args.prepend(thisArg);
3210 }
3211 } else {
3212 // We are seeing a normal method invocation; translate this as usual.
3213 tree.meth = translate(tree.meth);
3214
3215 // If the translated method itself is an Apply tree, we are
3216 // seeing an access method invocation. In this case, append
3217 // the method arguments to the arguments of the access method.
3218 if (tree.meth.hasTag(APPLY)) {
3219 JCMethodInvocation app = (JCMethodInvocation)tree.meth;
3220 app.args = tree.args.prependList(app.args);
3221 result = app;
3222 return;
3223 }
3224 }
3225 if (tree.args.stream().anyMatch(c -> c == null)) {
3226 throw new AssertionError("Whooops before: " + tree);
3227 }
3228 result = tree;
3229 }
3230
3231 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) {
3232 List<JCExpression> args = _args;
3233 if (parameters.isEmpty()) return args;
3234 boolean anyChanges = false;
3235 ListBuffer<JCExpression> result = new ListBuffer<>();
3236 while (parameters.tail.nonEmpty()) {
3237 JCExpression arg = translate(args.head, parameters.head);
3238 anyChanges |= (arg != args.head);
3239 result.append(arg);
3240 args = args.tail;
3241 parameters = parameters.tail;
3242 }
3243 Type parameter = parameters.head;
3244 if (varargsElement != null) {
3245 anyChanges = true;
3246 ListBuffer<JCExpression> elems = new ListBuffer<>();
3247 while (args.nonEmpty()) {
3248 JCExpression arg = translate(args.head, varargsElement);
3249 elems.append(arg);
3250 args = args.tail;
3251 }
3252 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement),
3253 List.nil(),
3254 elems.toList());
3255 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass);
3256 result.append(boxedArgs);
3257 } else {
3258 if (args.length() != 1) throw new AssertionError(args);
3259 JCExpression arg = translate(args.head, parameter);
3260 anyChanges |= (arg != args.head);
3261 result.append(arg);
3262 if (!anyChanges) return _args;
3263 }
3264 return result.toList();
3265 }
3266
3267 /** Expand a boxing or unboxing conversion if needed. */
3268 @SuppressWarnings("unchecked") // XXX unchecked
3269 <T extends JCExpression> T boxIfNeeded(T tree, Type type) {
3270 Assert.check(!type.hasTag(VOID));
3271 if (type.hasTag(NONE))
3272 return tree;
3273 boolean havePrimitive = tree.type.isPrimitive();
3274 if (havePrimitive == type.isPrimitive())
3275 return tree;
3276 if (havePrimitive) {
3277 Type unboxedTarget = types.unboxedType(type);
3278 if (!unboxedTarget.hasTag(NONE)) {
3279 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89;
3280 tree.type = unboxedTarget.constType(tree.type.constValue());
3281 return (T)boxPrimitive(tree, types.erasure(type));
3282 } else {
3283 tree = (T)boxPrimitive(tree);
3284 }
3285 } else {
3286 tree = (T)unbox(tree, type);
3287 }
3288 return tree;
3289 }
3290
3291 /** Box up a single primitive expression. */
3292 JCExpression boxPrimitive(JCExpression tree) {
3293 return boxPrimitive(tree, types.boxedClass(tree.type).type);
3294 }
3295
3296 /** Box up a single primitive expression. */
3297 JCExpression boxPrimitive(JCExpression tree, Type box) {
3298 make_at(tree.pos());
3299 Symbol valueOfSym = lookupMethod(tree.pos(),
3300 names.valueOf,
3301 box,
3302 List.<Type>nil()
3303 .prepend(tree.type));
3304 return make.App(make.QualIdent(valueOfSym), List.of(tree));
3305 }
3306
3307 /** Unbox an object to a primitive value. */
3308 JCExpression unbox(JCExpression tree, Type primitive) {
3309 Type unboxedType = types.unboxedType(tree.type);
3310 if (unboxedType.hasTag(NONE)) {
3311 unboxedType = primitive;
3312 if (!unboxedType.isPrimitive())
3313 throw new AssertionError(unboxedType);
3314 make_at(tree.pos());
3315 tree = make.TypeCast(types.boxedClass(unboxedType).type, tree);
3316 } else {
3317 // There must be a conversion from unboxedType to primitive.
3318 if (!types.isSubtype(unboxedType, primitive))
3319 throw new AssertionError(tree);
3320 }
3321 make_at(tree.pos());
3322 Symbol valueSym = lookupMethod(tree.pos(),
3323 unboxedType.tsym.name.append(names.Value), // x.intValue()
3324 tree.type,
3325 List.nil());
3326 return make.App(make.Select(tree, valueSym));
3327 }
3328
3329 /** Visitor method for parenthesized expressions.
3330 * If the subexpression has changed, omit the parens.
3331 */
3332 public void visitParens(JCParens tree) {
3333 JCTree expr = translate(tree.expr);
3334 result = ((expr == tree.expr) ? tree : expr);
3335 }
3336
3337 public void visitIndexed(JCArrayAccess tree) {
3338 tree.indexed = translate(tree.indexed);
3339 tree.index = translate(tree.index, syms.intType);
3340 result = tree;
3341 }
3342
3343 public void visitAssign(JCAssign tree) {
3344 tree.lhs = translate(tree.lhs, tree);
3345 tree.rhs = translate(tree.rhs, tree.lhs.type);
3346
3347 // If translated left hand side is an Apply, we are
3348 // seeing an access method invocation. In this case, append
3349 // right hand side as last argument of the access method.
3350 if (tree.lhs.hasTag(APPLY)) {
3351 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3352 app.args = List.of(tree.rhs).prependList(app.args);
3353 result = app;
3354 } else {
3355 result = tree;
3356 }
3357 }
3358
3359 public void visitAssignop(final JCAssignOp tree) {
3360 final boolean boxingReq = !tree.lhs.type.isPrimitive() &&
3361 tree.operator.type.getReturnType().isPrimitive();
3362
3363 AssignopDependencyScanner depScanner = new AssignopDependencyScanner(tree);
3364 depScanner.scan(tree.rhs);
3365
3366 if (boxingReq || depScanner.dependencyFound) {
3367 // boxing required; need to rewrite as x = (unbox typeof x)(x op y);
3368 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y)
3369 // (but without recomputing x)
3370 JCTree newTree = abstractLval(tree.lhs, lhs -> {
3371 Tag newTag = tree.getTag().noAssignOp();
3372 // Erasure (TransTypes) can change the type of
3373 // tree.lhs. However, we can still get the
3374 // unerased type of tree.lhs as it is stored
3375 // in tree.type in Attr.
3376 OperatorSymbol newOperator = operators.resolveBinary(tree,
3377 newTag,
3378 tree.type,
3379 tree.rhs.type);
3380 //Need to use the "lhs" at two places, once on the future left hand side
3381 //and once in the future binary operator. But further processing may change
3382 //the components of the tree in place (see visitSelect for e.g. <Class>.super.<ident>),
3383 //so cloning the tree to avoid interference between the uses:
3384 JCExpression expr = (JCExpression) lhs.clone();
3385 if (expr.type != tree.type)
3386 expr = make.TypeCast(tree.type, expr);
3387 JCBinary opResult = make.Binary(newTag, expr, tree.rhs);
3388 opResult.operator = newOperator;
3389 opResult.type = newOperator.type.getReturnType();
3390 JCExpression newRhs = boxingReq ?
3391 make.TypeCast(types.unboxedType(tree.type), opResult) :
3392 opResult;
3393 return make.Assign(lhs, newRhs).setType(tree.type);
3394 });
3395 result = translate(newTree);
3396 return;
3397 }
3398 tree.lhs = translate(tree.lhs, tree);
3399 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
3400
3401 // If translated left hand side is an Apply, we are
3402 // seeing an access method invocation. In this case, append
3403 // right hand side as last argument of the access method.
3404 if (tree.lhs.hasTag(APPLY)) {
3405 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3406 // if operation is a += on strings,
3407 // make sure to convert argument to string
3408 JCExpression rhs = tree.operator.opcode == string_add
3409 ? makeString(tree.rhs)
3410 : tree.rhs;
3411 app.args = List.of(rhs).prependList(app.args);
3412 result = app;
3413 } else {
3414 result = tree;
3415 }
3416 }
3417
3418 class AssignopDependencyScanner extends TreeScanner {
3419
3420 Symbol sym;
3421 boolean dependencyFound = false;
3422
3423 AssignopDependencyScanner(JCAssignOp tree) {
3424 this.sym = TreeInfo.symbol(tree.lhs);
3425 }
3426
3427 @Override
3428 public void scan(JCTree tree) {
3429 if (tree != null && sym != null) {
3430 tree.accept(this);
3431 }
3432 }
3433
3434 @Override
3435 public void visitAssignop(JCAssignOp tree) {
3436 if (TreeInfo.symbol(tree.lhs) == sym) {
3437 dependencyFound = true;
3438 return;
3439 }
3440 super.visitAssignop(tree);
3441 }
3442
3443 @Override
3444 public void visitUnary(JCUnary tree) {
3445 if (TreeInfo.symbol(tree.arg) == sym) {
3446 dependencyFound = true;
3447 return;
3448 }
3449 super.visitUnary(tree);
3450 }
3451 }
3452
3453 /** Lower a tree of the form e++ or e-- where e is an object type */
3454 JCExpression lowerBoxedPostop(final JCUnary tree) {
3455 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2
3456 // or
3457 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2
3458 // where OP is += or -=
3459 final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST);
3460 return abstractLval(tree.arg, tmp1 -> abstractRval(tmp1, tree.arg.type, tmp2 -> {
3461 Tag opcode = (tree.hasTag(POSTINC))
3462 ? PLUS_ASG : MINUS_ASG;
3463 //"tmp1" and "tmp2" may refer to the same instance
3464 //(for e.g. <Class>.super.<ident>). But further processing may
3465 //change the components of the tree in place (see visitSelect),
3466 //so cloning the tree to avoid interference between the two uses:
3467 JCExpression lhs = (JCExpression)tmp1.clone();
3468 lhs = cast
3469 ? make.TypeCast(tree.arg.type, lhs)
3470 : lhs;
3471 JCExpression update = makeAssignop(opcode,
3472 lhs,
3473 make.Literal(1));
3474 return makeComma(update, tmp2);
3475 }));
3476 }
3477
3478 public void visitUnary(JCUnary tree) {
3479 boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp();
3480 if (isUpdateOperator && !tree.arg.type.isPrimitive()) {
3481 switch(tree.getTag()) {
3482 case PREINC: // ++ e
3483 // translate to e += 1
3484 case PREDEC: // -- e
3485 // translate to e -= 1
3486 {
3487 JCTree.Tag opcode = (tree.hasTag(PREINC))
3488 ? PLUS_ASG : MINUS_ASG;
3489 JCAssignOp newTree = makeAssignop(opcode,
3490 tree.arg,
3491 make.Literal(1));
3492 result = translate(newTree, tree.type);
3493 return;
3494 }
3495 case POSTINC: // e ++
3496 case POSTDEC: // e --
3497 {
3498 result = translate(lowerBoxedPostop(tree), tree.type);
3499 return;
3500 }
3501 }
3502 throw new AssertionError(tree);
3503 }
3504
3505 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type);
3506
3507 if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) {
3508 tree.type = cfolder.fold1(bool_not, tree.arg.type);
3509 }
3510
3511 // If translated left hand side is an Apply, we are
3512 // seeing an access method invocation. In this case, return
3513 // that access method invocation as result.
3514 if (isUpdateOperator && tree.arg.hasTag(APPLY)) {
3515 result = tree.arg;
3516 } else {
3517 result = tree;
3518 }
3519 }
3520
3521 public void visitBinary(JCBinary tree) {
3522 List<Type> formals = tree.operator.type.getParameterTypes();
3523 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head);
3524 switch (tree.getTag()) {
3525 case OR:
3526 if (isTrue(lhs)) {
3527 result = lhs;
3528 return;
3529 }
3530 if (isFalse(lhs)) {
3531 result = translate(tree.rhs, formals.tail.head);
3532 return;
3533 }
3534 break;
3535 case AND:
3536 if (isFalse(lhs)) {
3537 result = lhs;
3538 return;
3539 }
3540 if (isTrue(lhs)) {
3541 result = translate(tree.rhs, formals.tail.head);
3542 return;
3543 }
3544 break;
3545 }
3546 tree.rhs = translate(tree.rhs, formals.tail.head);
3547 result = tree;
3548 }
3549
3550 public void visitIdent(JCIdent tree) {
3551 result = access(tree.sym, tree, enclOp, false);
3552 }
3553
3554 /** Translate away the foreach loop. */
3555 public void visitForeachLoop(JCEnhancedForLoop tree) {
3556 if (types.elemtype(tree.expr.type) == null)
3557 visitIterableForeachLoop(tree);
3558 else
3559 visitArrayForeachLoop(tree);
3560 }
3561 // where
3562 /**
3563 * A statement of the form
3564 *
3565 * <pre>
3566 * for ( T v : arrayexpr ) stmt;
3567 * </pre>
3568 *
3569 * (where arrayexpr is of an array type) gets translated to
3570 *
3571 * <pre>{@code
3572 * for ( { arraytype #arr = arrayexpr;
3573 * int #len = array.length;
3574 * int #i = 0; };
3575 * #i < #len; i$++ ) {
3576 * T v = arr$[#i];
3577 * stmt;
3578 * }
3579 * }</pre>
3580 *
3581 * where #arr, #len, and #i are freshly named synthetic local variables.
3582 */
3583 private void visitArrayForeachLoop(JCEnhancedForLoop tree) {
3584 make_at(tree.expr.pos());
3585 VarSymbol arraycache = new VarSymbol(SYNTHETIC,
3586 names.fromString("arr" + target.syntheticNameChar()),
3587 tree.expr.type,
3588 currentMethodSym);
3589 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr);
3590 VarSymbol lencache = new VarSymbol(SYNTHETIC,
3591 names.fromString("len" + target.syntheticNameChar()),
3592 syms.intType,
3593 currentMethodSym);
3594 JCStatement lencachedef = make.
3595 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar));
3596 VarSymbol index = new VarSymbol(SYNTHETIC,
3597 names.fromString("i" + target.syntheticNameChar()),
3598 syms.intType,
3599 currentMethodSym);
3600
3601 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0));
3602 indexdef.init.type = indexdef.type = syms.intType.constType(0);
3603
3604 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef);
3605 JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache));
3606
3607 JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index)));
3608
3609 Type elemtype = types.elemtype(tree.expr.type);
3610 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache),
3611 make.Ident(index)).setType(elemtype);
3612 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods,
3613 tree.var.name,
3614 tree.var.vartype,
3615 loopvarinit).setType(tree.var.type);
3616 loopvardef.sym = tree.var.sym;
3617 JCBlock body = make.
3618 Block(0, List.of(loopvardef, tree.body));
3619
3620 result = translate(make.
3621 ForLoop(loopinit,
3622 cond,
3623 List.of(step),
3624 body));
3625 patchTargets(body, tree, result);
3626 }
3627 /** Patch up break and continue targets. */
3628 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) {
3629 class Patcher extends TreeScanner {
3630 public void visitBreak(JCBreak tree) {
3631 if (tree.target == src)
3632 tree.target = dest;
3633 }
3634 public void visitYield(JCYield tree) {
3635 if (tree.target == src)
3636 tree.target = dest;
3637 scan(tree.value);
3638 }
3639 public void visitContinue(JCContinue tree) {
3640 if (tree.target == src)
3641 tree.target = dest;
3642 }
3643 public void visitClassDef(JCClassDecl tree) {}
3644 }
3645 new Patcher().scan(body);
3646 }
3647 /**
3648 * A statement of the form
3649 *
3650 * <pre>
3651 * for ( T v : coll ) stmt ;
3652 * </pre>
3653 *
3654 * (where coll implements {@code Iterable<? extends T>}) gets translated to
3655 *
3656 * <pre>{@code
3657 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) {
3658 * T v = (T) #i.next();
3659 * stmt;
3660 * }
3661 * }</pre>
3662 *
3663 * where #i is a freshly named synthetic local variable.
3664 */
3665 private void visitIterableForeachLoop(JCEnhancedForLoop tree) {
3666 make_at(tree.expr.pos());
3667 Type iteratorTarget = syms.objectType;
3668 Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type),
3669 syms.iterableType.tsym);
3670 if (iterableType.getTypeArguments().nonEmpty())
3671 iteratorTarget = types.erasure(iterableType.getTypeArguments().head);
3672 tree.expr.type = types.erasure(types.skipTypeVars(tree.expr.type, false));
3673 tree.expr = transTypes.coerce(attrEnv, tree.expr, types.erasure(iterableType));
3674 Symbol iterator = lookupMethod(tree.expr.pos(),
3675 names.iterator,
3676 tree.expr.type,
3677 List.nil());
3678 Assert.check(types.isSameType(types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)), types.erasure(syms.iteratorType)));
3679 VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()),
3680 types.erasure(syms.iteratorType),
3681 currentMethodSym);
3682
3683 JCStatement init = make.
3684 VarDef(itvar, make.App(make.Select(tree.expr, iterator)
3685 .setType(types.erasure(iterator.type))));
3686
3687 Symbol hasNext = lookupMethod(tree.expr.pos(),
3688 names.hasNext,
3689 itvar.type,
3690 List.nil());
3691 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext));
3692 Symbol next = lookupMethod(tree.expr.pos(),
3693 names.next,
3694 itvar.type,
3695 List.nil());
3696 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next));
3697 if (tree.var.type.isPrimitive())
3698 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit);
3699 else
3700 vardefinit = make.TypeCast(tree.var.type, vardefinit);
3701 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods,
3702 tree.var.name,
3703 tree.var.vartype,
3704 vardefinit).setType(tree.var.type);
3705 indexDef.sym = tree.var.sym;
3706 JCBlock body = make.Block(0, List.of(indexDef, tree.body));
3707 body.bracePos = TreeInfo.endPos(tree.body);
3708 result = translate(make.
3709 ForLoop(List.of(init),
3710 cond,
3711 List.nil(),
3712 body));
3713 patchTargets(body, tree, result);
3714 }
3715
3716 public void visitVarDef(JCVariableDecl tree) {
3717 MethodSymbol oldMethodSym = currentMethodSym;
3718 int prevVariableIndex = variableIndex;
3719 tree.mods = translate(tree.mods);
3720 tree.vartype = translate(tree.vartype);
3721 if (currentMethodSym == null) {
3722 // A class or instance field initializer.
3723 currentMethodSym =
3724 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK,
3725 names.empty, null,
3726 currentClass);
3727 }
3728 try {
3729 if (tree.init != null) tree.init = translate(tree.init, tree.type);
3730 result = tree;
3731 } finally {
3732 currentMethodSym = oldMethodSym;
3733 variableIndex = prevVariableIndex;
3734 }
3735 }
3736
3737 public void visitBlock(JCBlock tree) {
3738 MethodSymbol oldMethodSym = currentMethodSym;
3739 if (currentMethodSym == null) {
3740 // Block is a static or instance initializer.
3741 currentMethodSym =
3742 new MethodSymbol(tree.flags | BLOCK,
3743 names.empty, null,
3744 currentClass);
3745 }
3746 int prevVariableIndex = variableIndex;
3747 try {
3748 variableIndex = 0;
3749 super.visitBlock(tree);
3750 } finally {
3751 currentMethodSym = oldMethodSym;
3752 variableIndex = prevVariableIndex;
3753 }
3754 }
3755
3756 public void visitDoLoop(JCDoWhileLoop tree) {
3757 tree.body = translate(tree.body);
3758 tree.cond = translate(tree.cond, syms.booleanType);
3759 result = tree;
3760 }
3761
3762 public void visitWhileLoop(JCWhileLoop tree) {
3763 tree.cond = translate(tree.cond, syms.booleanType);
3764 tree.body = translate(tree.body);
3765 result = tree;
3766 }
3767
3768 public void visitForLoop(JCForLoop tree) {
3769 tree.init = translate(tree.init);
3770 if (tree.cond != null)
3771 tree.cond = translate(tree.cond, syms.booleanType);
3772 tree.step = translate(tree.step);
3773 tree.body = translate(tree.body);
3774 result = tree;
3775 }
3776
3777 public void visitReturn(JCReturn tree) {
3778 if (tree.expr != null)
3779 tree.expr = translate(tree.expr,
3780 currentRestype);
3781 result = tree;
3782 }
3783
3784 @Override
3785 public void visitLambda(JCLambda tree) {
3786 Type prevRestype = currentRestype;
3787 try {
3788 currentRestype = types.erasure(tree.getDescriptorType(types)).getReturnType();
3789 // represent void results as NO_TYPE, to avoid unnecessary boxing in boxIfNeeded
3790 if (currentRestype.hasTag(VOID))
3791 currentRestype = Type.noType;
3792 tree.body = tree.getBodyKind() == BodyKind.EXPRESSION ?
3793 translate((JCExpression) tree.body, currentRestype) :
3794 translate(tree.body);
3795 } finally {
3796 currentRestype = prevRestype;
3797 }
3798 result = tree;
3799 }
3800
3801 public void visitSwitch(JCSwitch tree) {
3802 List<JCCase> cases = tree.patternSwitch ? addDefaultIfNeeded(tree.patternSwitch,
3803 tree.wasEnumSelector,
3804 tree.cases)
3805 : tree.cases;
3806 handleSwitch(tree, tree.selector, cases);
3807 }
3808
3809 @Override
3810 public void visitSwitchExpression(JCSwitchExpression tree) {
3811 List<JCCase> cases = addDefaultIfNeeded(tree.patternSwitch, tree.wasEnumSelector, tree.cases);
3812 handleSwitch(tree, tree.selector, cases);
3813 }
3814
3815 private List<JCCase> addDefaultIfNeeded(boolean patternSwitch, boolean wasEnumSelector,
3816 List<JCCase> cases) {
3817 if (cases.stream().flatMap(c -> c.labels.stream()).noneMatch(p -> p.hasTag(Tag.DEFAULTCASELABEL))) {
3818 boolean matchException = useMatchException;
3819 matchException |= patternSwitch && !wasEnumSelector;
3820 Type exception = matchException ? syms.matchExceptionType
3821 : syms.incompatibleClassChangeErrorType;
3822 List<JCExpression> params = matchException ? List.of(makeNull(), makeNull())
3823 : List.nil();
3824 JCThrow thr = make.Throw(makeNewClass(exception, params));
3825 JCCase c = make.Case(JCCase.STATEMENT, List.of(make.DefaultCaseLabel()), null, List.of(thr), null);
3826 cases = cases.prepend(c);
3827 }
3828
3829 return cases;
3830 }
3831
3832 private void handleSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
3833 //expand multiple label cases:
3834 ListBuffer<JCCase> convertedCases = new ListBuffer<>();
3835
3836 for (JCCase c : cases) {
3837 switch (c.labels.size()) {
3838 case 0: //default
3839 case 1: //single label
3840 convertedCases.append(c);
3841 break;
3842 default: //multiple labels, expand:
3843 //case C1, C2, C3: ...
3844 //=>
3845 //case C1:
3846 //case C2:
3847 //case C3: ...
3848 List<JCCaseLabel> patterns = c.labels;
3849 while (patterns.tail.nonEmpty()) {
3850 convertedCases.append(make_at(c.pos()).Case(JCCase.STATEMENT,
3851 List.of(patterns.head),
3852 null,
3853 List.nil(),
3854 null));
3855 patterns = patterns.tail;
3856 }
3857 c.labels = patterns;
3858 convertedCases.append(c);
3859 break;
3860 }
3861 }
3862
3863 for (JCCase c : convertedCases) {
3864 if (c.caseKind == JCCase.RULE && c.completesNormally) {
3865 JCBreak b = make.at(TreeInfo.endPos(c.stats.last())).Break(null);
3866 b.target = tree;
3867 c.stats = c.stats.append(b);
3868 }
3869 }
3870
3871 cases = convertedCases.toList();
3872
3873 Type selsuper = types.supertype(selector.type);
3874 boolean enumSwitch = selsuper != null &&
3875 (selector.type.tsym.flags() & ENUM) != 0;
3876 boolean stringSwitch = selsuper != null &&
3877 types.isSameType(selector.type, syms.stringType);
3878 boolean boxedSwitch = !enumSwitch && !stringSwitch && !selector.type.isPrimitive();
3879 selector = translate(selector, selector.type);
3880 cases = translateCases(cases);
3881 if (tree.hasTag(SWITCH)) {
3882 ((JCSwitch) tree).selector = selector;
3883 ((JCSwitch) tree).cases = cases;
3884 } else if (tree.hasTag(SWITCH_EXPRESSION)) {
3885 ((JCSwitchExpression) tree).selector = selector;
3886 ((JCSwitchExpression) tree).cases = cases;
3887 } else {
3888 Assert.error();
3889 }
3890 if (enumSwitch) {
3891 result = visitEnumSwitch(tree, selector, cases);
3892 } else if (stringSwitch) {
3893 result = visitStringSwitch(tree, selector, cases);
3894 } else if (boxedSwitch) {
3895 //An switch over boxed primitive. Pattern matching switches are already translated
3896 //by TransPatterns, so all non-primitive types are only boxed primitives:
3897 result = visitBoxedPrimitiveSwitch(tree, selector, cases);
3898 } else {
3899 result = tree;
3900 }
3901 }
3902
3903 public JCTree visitEnumSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
3904 TypeSymbol enumSym = selector.type.tsym;
3905 EnumMapping map = mapForEnum(tree.pos(), enumSym);
3906 make_at(tree.pos());
3907 Symbol ordinalMethod = lookupMethod(tree.pos(),
3908 names.ordinal,
3909 selector.type,
3910 List.nil());
3911 JCExpression newSelector;
3912
3913 if (cases.stream().anyMatch(c -> TreeInfo.isNullCaseLabel(c.labels.head))) {
3914 //for enum switches with case null, do:
3915 //switch ($selector != null ? $mapVar[$selector.ordinal()] : -1) {...}
3916 //replacing case null with case -1:
3917 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
3918 names.fromString("s" + variableIndex++ + this.target.syntheticNameChar()),
3919 selector.type,
3920 currentMethodSym);
3921 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type);
3922 newSelector = map.switchValue(
3923 make.App(make.Select(make.Ident(dollar_s),
3924 ordinalMethod)));
3925 newSelector =
3926 make.LetExpr(List.of(var),
3927 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()),
3928 newSelector,
3929 makeLit(syms.intType, -1))
3930 .setType(newSelector.type))
3931 .setType(newSelector.type);
3932 } else {
3933 newSelector = map.switchValue(
3934 make.App(make.Select(selector,
3935 ordinalMethod)));
3936 }
3937 ListBuffer<JCCase> newCases = new ListBuffer<>();
3938 for (JCCase c : cases) {
3939 if (c.labels.head.hasTag(CONSTANTCASELABEL)) {
3940 JCExpression pat;
3941 if (TreeInfo.isNullCaseLabel(c.labels.head)) {
3942 pat = makeLit(syms.intType, -1);
3943 } else {
3944 VarSymbol label = (VarSymbol)TreeInfo.symbol(((JCConstantCaseLabel) c.labels.head).expr);
3945 pat = map.caseValue(label);
3946 }
3947 newCases.append(make.Case(JCCase.STATEMENT, List.of(make.ConstantCaseLabel(pat)), null, c.stats, null));
3948 } else {
3949 newCases.append(c);
3950 }
3951 }
3952 JCTree enumSwitch;
3953 if (tree.hasTag(SWITCH)) {
3954 enumSwitch = make.Switch(newSelector, newCases.toList());
3955 } else if (tree.hasTag(SWITCH_EXPRESSION)) {
3956 enumSwitch = make.SwitchExpression(newSelector, newCases.toList());
3957 enumSwitch.setType(tree.type);
3958 } else {
3959 Assert.error();
3960 throw new AssertionError();
3961 }
3962 patchTargets(enumSwitch, tree, enumSwitch);
3963 return enumSwitch;
3964 }
3965
3966 public JCTree visitStringSwitch(JCTree tree, JCExpression selector, List<JCCase> caseList) {
3967 int alternatives = caseList.size();
3968
3969 if (alternatives == 0) { // Strange but legal possibility (only legal for switch statement)
3970 return make.at(tree.pos()).Exec(attr.makeNullCheck(selector));
3971 } else {
3972 /*
3973 * The general approach used is to translate a single
3974 * string switch statement into a series of two chained
3975 * switch statements: the first a synthesized statement
3976 * switching on the argument string's hash value and
3977 * computing a string's position in the list of original
3978 * case labels, if any, followed by a second switch on the
3979 * computed integer value. The second switch has the same
3980 * code structure as the original string switch statement
3981 * except that the string case labels are replaced with
3982 * positional integer constants starting at 0.
3983 *
3984 * The first switch statement can be thought of as an
3985 * inlined map from strings to their position in the case
3986 * label list. An alternate implementation would use an
3987 * actual Map for this purpose, as done for enum switches.
3988 *
3989 * With some additional effort, it would be possible to
3990 * use a single switch statement on the hash code of the
3991 * argument, but care would need to be taken to preserve
3992 * the proper control flow in the presence of hash
3993 * collisions and other complications, such as
3994 * fallthroughs. Switch statements with one or two
3995 * alternatives could also be specially translated into
3996 * if-then statements to omit the computation of the hash
3997 * code.
3998 *
3999 * The generated code assumes that the hashing algorithm
4000 * of String is the same in the compilation environment as
4001 * in the environment the code will run in. The string
4002 * hashing algorithm in the SE JDK has been unchanged
4003 * since at least JDK 1.2. Since the algorithm has been
4004 * specified since that release as well, it is very
4005 * unlikely to be changed in the future.
4006 *
4007 * Different hashing algorithms, such as the length of the
4008 * strings or a perfect hashing algorithm over the
4009 * particular set of case labels, could potentially be
4010 * used instead of String.hashCode.
4011 */
4012
4013 ListBuffer<JCStatement> stmtList = new ListBuffer<>();
4014
4015 // Map from String case labels to their original position in
4016 // the list of case labels.
4017 Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f);
4018
4019 // Map of hash codes to the string case labels having that hashCode.
4020 Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f);
4021
4022 int casePosition = 0;
4023 JCCase nullCase = null;
4024 int nullCaseLabel = -1;
4025
4026 for(JCCase oneCase : caseList) {
4027 if (oneCase.labels.head.hasTag(CONSTANTCASELABEL)) {
4028 if (TreeInfo.isNullCaseLabel(oneCase.labels.head)) {
4029 nullCase = oneCase;
4030 nullCaseLabel = casePosition;
4031 } else {
4032 JCExpression expression = ((JCConstantCaseLabel) oneCase.labels.head).expr;
4033 String labelExpr = (String) expression.type.constValue();
4034 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition);
4035 Assert.checkNull(mapping);
4036 int hashCode = labelExpr.hashCode();
4037
4038 Set<String> stringSet = hashToString.get(hashCode);
4039 if (stringSet == null) {
4040 stringSet = new LinkedHashSet<>(1, 1.0f);
4041 stringSet.add(labelExpr);
4042 hashToString.put(hashCode, stringSet);
4043 } else {
4044 boolean added = stringSet.add(labelExpr);
4045 Assert.check(added);
4046 }
4047 }
4048 }
4049 casePosition++;
4050 }
4051
4052 // Synthesize a switch statement that has the effect of
4053 // mapping from a string to the integer position of that
4054 // string in the list of case labels. This is done by
4055 // switching on the hashCode of the string followed by an
4056 // if-then-else chain comparing the input for equality
4057 // with all the case labels having that hash value.
4058
4059 /*
4060 * s$ = top of stack;
4061 * tmp$ = -1;
4062 * switch($s.hashCode()) {
4063 * case caseLabel.hashCode:
4064 * if (s$.equals("caseLabel_1")
4065 * tmp$ = caseLabelToPosition("caseLabel_1");
4066 * else if (s$.equals("caseLabel_2"))
4067 * tmp$ = caseLabelToPosition("caseLabel_2");
4068 * ...
4069 * break;
4070 * ...
4071 * }
4072 */
4073
4074 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
4075 names.fromString("s" + variableIndex++ + target.syntheticNameChar()),
4076 syms.stringType,
4077 currentMethodSym);
4078 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type));
4079
4080 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC,
4081 names.fromString("tmp" + variableIndex++ + target.syntheticNameChar()),
4082 syms.intType,
4083 currentMethodSym);
4084 JCVariableDecl dollar_tmp_def =
4085 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type);
4086 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType;
4087 stmtList.append(dollar_tmp_def);
4088 ListBuffer<JCCase> caseBuffer = new ListBuffer<>();
4089 // hashCode will trigger nullcheck on original switch expression
4090 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s),
4091 names.hashCode,
4092 List.nil()).setType(syms.intType);
4093 JCSwitch switch1 = make.Switch(hashCodeCall,
4094 caseBuffer.toList());
4095 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) {
4096 int hashCode = entry.getKey();
4097 Set<String> stringsWithHashCode = entry.getValue();
4098 Assert.check(stringsWithHashCode.size() >= 1);
4099
4100 JCStatement elsepart = null;
4101 for(String caseLabel : stringsWithHashCode ) {
4102 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s),
4103 names.equals,
4104 List.of(make.Literal(caseLabel)));
4105 elsepart = make.If(stringEqualsCall,
4106 make.Exec(make.Assign(make.Ident(dollar_tmp),
4107 make.Literal(caseLabelToPosition.get(caseLabel))).
4108 setType(dollar_tmp.type)),
4109 elsepart);
4110 }
4111
4112 ListBuffer<JCStatement> lb = new ListBuffer<>();
4113 JCBreak breakStmt = make.Break(null);
4114 breakStmt.target = switch1;
4115 lb.append(elsepart).append(breakStmt);
4116
4117 caseBuffer.append(make.Case(JCCase.STATEMENT,
4118 List.of(make.ConstantCaseLabel(make.Literal(hashCode))),
4119 null,
4120 lb.toList(),
4121 null));
4122 }
4123
4124 switch1.cases = caseBuffer.toList();
4125
4126 if (nullCase != null) {
4127 stmtList.append(make.If(makeBinary(NE, make.Ident(dollar_s), makeNull()), switch1, make.Exec(make.Assign(make.Ident(dollar_tmp),
4128 make.Literal(nullCaseLabel)).
4129 setType(dollar_tmp.type))).setType(syms.intType));
4130 } else {
4131 stmtList.append(switch1);
4132 }
4133
4134 // Make isomorphic switch tree replacing string labels
4135 // with corresponding integer ones from the label to
4136 // position map.
4137
4138 ListBuffer<JCCase> lb = new ListBuffer<>();
4139 for(JCCase oneCase : caseList ) {
4140 boolean isDefault = !oneCase.labels.head.hasTag(CONSTANTCASELABEL);
4141 JCExpression caseExpr;
4142 if (isDefault)
4143 caseExpr = null;
4144 else if (oneCase == nullCase) {
4145 caseExpr = make.Literal(nullCaseLabel);
4146 } else {
4147 JCExpression expression = ((JCConstantCaseLabel) oneCase.labels.head).expr;
4148 String name = (String) TreeInfo.skipParens(expression)
4149 .type.constValue();
4150 caseExpr = make.Literal(caseLabelToPosition.get(name));
4151 }
4152
4153 lb.append(make.Case(JCCase.STATEMENT, caseExpr == null ? List.of(make.DefaultCaseLabel())
4154 : List.of(make.ConstantCaseLabel(caseExpr)),
4155 null,
4156 oneCase.stats, null));
4157 }
4158
4159 if (tree.hasTag(SWITCH)) {
4160 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList());
4161 // Rewire up old unlabeled break statements to the
4162 // replacement switch being created.
4163 patchTargets(switch2, tree, switch2);
4164
4165 stmtList.append(switch2);
4166
4167 JCBlock res = make.Block(0L, stmtList.toList());
4168 res.bracePos = TreeInfo.endPos(tree);
4169 return res;
4170 } else {
4171 JCSwitchExpression switch2 = make.SwitchExpression(make.Ident(dollar_tmp), lb.toList());
4172
4173 // Rewire up old unlabeled break statements to the
4174 // replacement switch being created.
4175 patchTargets(switch2, tree, switch2);
4176
4177 switch2.setType(tree.type);
4178
4179 LetExpr res = make.LetExpr(stmtList.toList(), switch2);
4180
4181 res.needsCond = true;
4182 res.setType(tree.type);
4183
4184 return res;
4185 }
4186 }
4187 }
4188
4189 private JCTree visitBoxedPrimitiveSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
4190 JCExpression newSelector;
4191
4192 if (cases.stream().anyMatch(c -> TreeInfo.isNullCaseLabel(c.labels.head))) {
4193 //a switch over a boxed primitive, with a null case. Pick two constants that are
4194 //not used by any branch in the case (c1 and c2), close to other constants that are
4195 //used in the switch. Then do:
4196 //switch ($selector != null ? $selector != c1 ? $selector : c2 : c1) {...}
4197 //replacing case null with case c1
4198 Set<Integer> constants = new LinkedHashSet<>();
4199 JCCase nullCase = null;
4200
4201 for (JCCase c : cases) {
4202 if (TreeInfo.isNullCaseLabel(c.labels.head)) {
4203 nullCase = c;
4204 } else if (!c.labels.head.hasTag(DEFAULTCASELABEL)) {
4205 constants.add((int) ((JCConstantCaseLabel) c.labels.head).expr.type.constValue());
4206 }
4207 }
4208
4209 Assert.checkNonNull(nullCase);
4210
4211 int nullValue = constants.isEmpty() ? 0 : constants.iterator().next();
4212
4213 while (constants.contains(nullValue)) nullValue++;
4214
4215 constants.add(nullValue);
4216 nullCase.labels.head = make.ConstantCaseLabel(makeLit(syms.intType, nullValue));
4217
4218 int replacementValue = nullValue;
4219
4220 while (constants.contains(replacementValue)) replacementValue++;
4221
4222 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
4223 names.fromString("s" + variableIndex++ + this.target.syntheticNameChar()),
4224 selector.type,
4225 currentMethodSym);
4226 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type);
4227 JCExpression nullValueReplacement =
4228 make.Conditional(makeBinary(NE,
4229 unbox(make.Ident(dollar_s), syms.intType),
4230 makeLit(syms.intType, nullValue)),
4231 unbox(make.Ident(dollar_s), syms.intType),
4232 makeLit(syms.intType, replacementValue))
4233 .setType(syms.intType);
4234 JCExpression nullCheck =
4235 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()),
4236 nullValueReplacement,
4237 makeLit(syms.intType, nullValue))
4238 .setType(syms.intType);
4239 newSelector = make.LetExpr(List.of(var), nullCheck).setType(syms.intType);
4240 } else {
4241 newSelector = unbox(selector, syms.intType);
4242 }
4243
4244 if (tree.hasTag(SWITCH)) {
4245 ((JCSwitch) tree).selector = newSelector;
4246 } else {
4247 ((JCSwitchExpression) tree).selector = newSelector;
4248 }
4249
4250 return tree;
4251 }
4252
4253 @Override
4254 public void visitBreak(JCBreak tree) {
4255 result = tree;
4256 }
4257
4258 @Override
4259 public void visitYield(JCYield tree) {
4260 tree.value = translate(tree.value, tree.target.type);
4261 result = tree;
4262 }
4263
4264 public void visitNewArray(JCNewArray tree) {
4265 tree.elemtype = translate(tree.elemtype);
4266 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail)
4267 if (t.head != null) t.head = translate(t.head, syms.intType);
4268 tree.elems = translate(tree.elems, types.elemtype(tree.type));
4269 result = tree;
4270 }
4271
4272 public void visitSelect(JCFieldAccess tree) {
4273 // need to special case-access of the form C.super.x
4274 // these will always need an access method, unless C
4275 // is a default interface subclassed by the current class.
4276 boolean qualifiedSuperAccess =
4277 tree.selected.hasTag(SELECT) &&
4278 TreeInfo.name(tree.selected) == names._super &&
4279 !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass);
4280 tree.selected = translate(tree.selected);
4281 if (tree.name == names._class && tree.selected.type.isPrimitiveOrVoid()) {
4282 result = classOf(tree.selected);
4283 }
4284 else if (tree.name == names._super &&
4285 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) {
4286 //default super call!! Not a classic qualified super call
4287 TypeSymbol supSym = tree.selected.type.tsym;
4288 Assert.checkNonNull(types.asSuper(currentClass.type, supSym));
4289 result = tree;
4290 }
4291 else if (tree.name == names._this || tree.name == names._super) {
4292 result = makeThis(tree.pos(), tree.selected.type.tsym);
4293 }
4294 else
4295 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess);
4296 }
4297
4298 public void visitLetExpr(LetExpr tree) {
4299 tree.defs = translate(tree.defs);
4300 tree.expr = translate(tree.expr, tree.type);
4301 result = tree;
4302 }
4303
4304 // There ought to be nothing to rewrite here;
4305 // we don't generate code.
4306 public void visitAnnotation(JCAnnotation tree) {
4307 result = tree;
4308 }
4309
4310 @Override
4311 public void visitTry(JCTry tree) {
4312 if (tree.resources.nonEmpty()) {
4313 result = makeTwrTry(tree);
4314 return;
4315 }
4316
4317 boolean hasBody = tree.body.getStatements().nonEmpty();
4318 boolean hasCatchers = tree.catchers.nonEmpty();
4319 boolean hasFinally = tree.finalizer != null &&
4320 tree.finalizer.getStatements().nonEmpty();
4321
4322 if (!hasCatchers && !hasFinally) {
4323 result = translate(tree.body);
4324 return;
4325 }
4326
4327 if (!hasBody) {
4328 if (hasFinally) {
4329 result = translate(tree.finalizer);
4330 } else {
4331 result = translate(tree.body);
4332 }
4333 return;
4334 }
4335
4336 // no optimizations possible
4337 super.visitTry(tree);
4338 }
4339
4340 /* ************************************************************************
4341 * main method
4342 *************************************************************************/
4343
4344 /** Translate a toplevel class and return a list consisting of
4345 * the translated class and translated versions of all inner classes.
4346 * @param env The attribution environment current at the class definition.
4347 * We need this for resolving some additional symbols.
4348 * @param cdef The tree representing the class definition.
4349 */
4350 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) {
4351 ListBuffer<JCTree> translated = null;
4352 try {
4353 attrEnv = env;
4354 this.make = make;
4355 endPosTable = env.toplevel.endPositions;
4356 currentClass = null;
4357 currentRestype = null;
4358 currentMethodDef = null;
4359 outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null;
4360 outermostMemberDef = null;
4361 this.translated = new ListBuffer<>();
4362 classdefs = new HashMap<>();
4363 actualSymbols = new HashMap<>();
4364 freevarCache = new HashMap<>();
4365 proxies = new HashMap<>();
4366 twrVars = WriteableScope.create(syms.noSymbol);
4367 outerThisStack = List.nil();
4368 accessNums = new HashMap<>();
4369 accessSyms = new HashMap<>();
4370 accessConstrs = new HashMap<>();
4371 accessConstrTags = List.nil();
4372 accessed = new ListBuffer<>();
4373 translate(cdef, (JCExpression)null);
4374 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail)
4375 makeAccessible(l.head);
4376 for (EnumMapping map : enumSwitchMap.values())
4377 map.translate();
4378 checkConflicts(this.translated.toList());
4379 checkAccessConstructorTags();
4380 translated = this.translated;
4381 } finally {
4382 // note that recursive invocations of this method fail hard
4383 attrEnv = null;
4384 this.make = null;
4385 endPosTable = null;
4386 currentClass = null;
4387 currentRestype = null;
4388 currentMethodDef = null;
4389 outermostClassDef = null;
4390 outermostMemberDef = null;
4391 this.translated = null;
4392 classdefs = null;
4393 actualSymbols = null;
4394 freevarCache = null;
4395 proxies = null;
4396 outerThisStack = null;
4397 accessNums = null;
4398 accessSyms = null;
4399 accessConstrs = null;
4400 accessConstrTags = null;
4401 accessed = null;
4402 enumSwitchMap.clear();
4403 assertionsDisabledClassCache = null;
4404 }
4405 return translated.toList();
4406 }
4407
4408 // needed for the lambda deserialization method, which is expressed as a big switch on strings
4409 public JCMethodDecl translateMethod(Env<AttrContext> env, JCMethodDecl methodDecl, TreeMaker make) {
4410 try {
4411 this.attrEnv = env;
4412 this.make = make;
4413 this.currentClass = methodDecl.sym.enclClass();
4414 proxies = new HashMap<>();
4415 return translate(methodDecl);
4416 } finally {
4417 this.attrEnv = null;
4418 this.make = null;
4419 this.currentClass = null;
4420 // the two fields below are set when visiting the method
4421 this.currentMethodSym = null;
4422 this.currentMethodDef = null;
4423 this.proxies = null;
4424 }
4425 }
4426 }