1 /*
2 * Copyright (c) 1999, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.comp;
27
28 import java.util.*;
29 import java.util.stream.Collectors;
30
31 import com.sun.source.tree.LambdaExpressionTree.BodyKind;
32 import com.sun.tools.javac.code.*;
33 import com.sun.tools.javac.code.Kinds.KindSelector;
34 import com.sun.tools.javac.code.Scope.WriteableScope;
35 import com.sun.tools.javac.jvm.*;
36 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
37 import com.sun.tools.javac.main.Option.PkgInfo;
38 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
39 import com.sun.tools.javac.tree.*;
40 import com.sun.tools.javac.util.*;
41 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
42 import com.sun.tools.javac.util.List;
43
44 import com.sun.tools.javac.code.Symbol.*;
45 import com.sun.tools.javac.code.Symbol.OperatorSymbol.AccessCode;
46 import com.sun.tools.javac.resources.CompilerProperties.Errors;
47 import com.sun.tools.javac.tree.JCTree.*;
48 import com.sun.tools.javac.code.Type.*;
49
50 import com.sun.tools.javac.jvm.Target;
51
52 import static com.sun.tools.javac.code.Flags.*;
53 import static com.sun.tools.javac.code.Flags.BLOCK;
54 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
55 import static com.sun.tools.javac.code.TypeTag.*;
56 import static com.sun.tools.javac.code.Kinds.Kind.*;
57 import com.sun.tools.javac.code.Source.Feature;
58 import static com.sun.tools.javac.jvm.ByteCodes.*;
59 import com.sun.tools.javac.tree.JCTree.JCBreak;
60 import com.sun.tools.javac.tree.JCTree.JCCase;
61 import com.sun.tools.javac.tree.JCTree.JCExpression;
62 import com.sun.tools.javac.tree.JCTree.JCExpressionStatement;
63
64 import static com.sun.tools.javac.tree.JCTree.JCOperatorExpression.OperandPos.LEFT;
65 import com.sun.tools.javac.tree.JCTree.JCSwitchExpression;
66
67 import static com.sun.tools.javac.tree.JCTree.Tag.*;
68
69 /** This pass translates away some syntactic sugar: inner classes,
70 * class literals, assertions, foreach loops, etc.
71 *
72 * <p><b>This is NOT part of any supported API.
73 * If you write code that depends on this, you do so at your own risk.
74 * This code and its internal interfaces are subject to change or
75 * deletion without notice.</b>
76 */
77 public class Lower extends TreeTranslator {
78 protected static final Context.Key<Lower> lowerKey = new Context.Key<>();
79
80 public static Lower instance(Context context) {
81 Lower instance = context.get(lowerKey);
82 if (instance == null)
83 instance = new Lower(context);
84 return instance;
85 }
86
87 private final Names names;
88 private final Log log;
89 private final Symtab syms;
90 private final Resolve rs;
91 private final Operators operators;
92 private final Check chk;
93 private final Attr attr;
94 private TreeMaker make;
95 private DiagnosticPosition make_pos;
96 private final ConstFold cfolder;
97 private final Target target;
98 private final TypeEnvs typeEnvs;
99 private final Name dollarAssertionsDisabled;
100 private final Types types;
101 private final TransTypes transTypes;
102 private final boolean debugLower;
103 private final boolean disableProtectedAccessors; // experimental
104 private final PkgInfo pkginfoOpt;
105 private final boolean optimizeOuterThis;
106 private final boolean nullCheckOuterThis;
107 private final boolean useMatchException;
108 private final HashMap<TypePairs, String> typePairToName;
109 private final boolean allowValueClasses;
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 this.allowValueClasses = preview.isEnabled() && Feature.VALUE_CLASSES.allowedInSource(source);
146 }
147
148 /** The currently enclosing class.
149 */
150 ClassSymbol currentClass;
151
152 /** A queue of all translated classes.
153 */
154 ListBuffer<JCTree> translated;
155
156 /** Environment for symbol lookup, set by translateTopLevelClass.
157 */
158 Env<AttrContext> attrEnv;
159
160 /* ************************************************************************
161 * Global mappings
162 *************************************************************************/
163
164 /** A hash table mapping local classes to their definitions.
165 */
166 Map<ClassSymbol, JCClassDecl> classdefs;
167
168 /** A hash table mapping local classes to a list of pruned trees.
169 */
170 public Map<ClassSymbol, List<JCTree>> prunedTree = new WeakHashMap<>();
171
172 /** A hash table mapping virtual accessed symbols in outer subclasses
173 * to the actually referred symbol in superclasses.
174 */
175 Map<Symbol,Symbol> actualSymbols;
176
177 /**
178 * The current expected return type.
179 */
180 Type currentRestype;
181
182 /** The current method definition.
183 */
184 JCMethodDecl currentMethodDef;
185
186 /** The current method symbol.
187 */
188 MethodSymbol currentMethodSym;
189
190 /** The currently enclosing outermost class definition.
191 */
192 JCClassDecl outermostClassDef;
193
194 /** The currently enclosing outermost member definition.
195 */
196 JCTree outermostMemberDef;
197
198 /** A navigator class for assembling a mapping from local class symbols
199 * to class definition trees.
200 * There is only one case; all other cases simply traverse down the tree.
201 */
202 class ClassMap extends TreeScanner {
203
204 /** All encountered class defs are entered into classdefs table.
205 */
206 public void visitClassDef(JCClassDecl tree) {
207 classdefs.put(tree.sym, tree);
208 super.visitClassDef(tree);
209 }
210 }
211 ClassMap classMap = new ClassMap();
212
213 /** Map a class symbol to its definition.
214 * @param c The class symbol of which we want to determine the definition.
215 */
216 JCClassDecl classDef(ClassSymbol c) {
217 // First lookup the class in the classdefs table.
218 JCClassDecl def = classdefs.get(c);
219 if (def == null && outermostMemberDef != null) {
220 // If this fails, traverse outermost member definition, entering all
221 // local classes into classdefs, and try again.
222 classMap.scan(outermostMemberDef);
223 def = classdefs.get(c);
224 }
225 if (def == null) {
226 // If this fails, traverse outermost class definition, entering all
227 // local classes into classdefs, and try again.
228 classMap.scan(outermostClassDef);
229 def = classdefs.get(c);
230 }
231 return def;
232 }
233
234 /**
235 * Get the enum constants for the given enum class symbol, if known.
236 * They will only be found if they are defined within the same top-level
237 * class as the class being compiled, so it's safe to assume that they
238 * can't change at runtime due to a recompilation.
239 */
240 List<Name> enumNamesFor(ClassSymbol c) {
241
242 // Find the class definition and verify it is an enum class
243 final JCClassDecl classDef = classDef(c);
244 if (classDef == null ||
245 (classDef.mods.flags & ENUM) == 0 ||
246 (types.supertype(currentClass.type).tsym.flags() & ENUM) != 0) {
247 return null;
248 }
249
250 // Gather the enum identifiers
251 ListBuffer<Name> idents = new ListBuffer<>();
252 for (List<JCTree> defs = classDef.defs; defs.nonEmpty(); defs=defs.tail) {
253 if (defs.head.hasTag(VARDEF) &&
254 (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
255 JCVariableDecl var = (JCVariableDecl)defs.head;
256 idents.append(var.name);
257 }
258 }
259 return idents.toList();
260 }
261
262 /** A hash table mapping class symbols to lists of free variables.
263 * accessed by them. Only free variables of the method immediately containing
264 * a class are associated with that class.
265 */
266 Map<ClassSymbol,List<VarSymbol>> freevarCache;
267
268 /** A navigator class for collecting the free variables accessed
269 * from a local class.
270 */
271 public class FreeVarCollector extends CaptureScanner {
272
273 protected FreeVarCollector(JCTree ownerTree) {
274 super(ownerTree);
275 }
276
277 protected void addFreeVars(ClassSymbol c) {
278 List<VarSymbol> fvs = freevarCache.get(c);
279 if (fvs != null) {
280 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
281 addFreeVar(l.head);
282 }
283 }
284 }
285
286 /** If tree refers to a class instance creation expression
287 * add all free variables of the freshly created class.
288 */
289 public void visitNewClass(JCNewClass tree) {
290 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
291 addFreeVars(c);
292 super.visitNewClass(tree);
293 }
294
295 /** If tree refers to a superclass constructor call,
296 * add all free variables of the superclass.
297 */
298 public void visitApply(JCMethodInvocation tree) {
299 if (TreeInfo.name(tree.meth) == names._super) {
300 addFreeVars((ClassSymbol) TreeInfo.symbol(tree.meth).owner);
301 }
302 super.visitApply(tree);
303 }
304 }
305
306 /** Return the variables accessed from within a local class, which
307 * are declared in the local class' owner.
308 * (in reverse order of first access).
309 */
310 List<VarSymbol> freevars(ClassSymbol c) {
311 List<VarSymbol> fvs = freevarCache.get(c);
312 if (fvs != null) {
313 return fvs;
314 }
315 FreeVarCollector collector = new FreeVarCollector(classDef(c));
316 fvs = collector.analyzeCaptures().reverse();
317 freevarCache.put(c, fvs);
318 return fvs;
319 }
320
321 Map<TypeSymbol,EnumMapping> enumSwitchMap = new LinkedHashMap<>();
322
323 EnumMapping mapForEnum(DiagnosticPosition pos, TypeSymbol enumClass) {
324
325 // If enum class is part of this compilation, just switch on ordinal value
326 if (enumClass.kind == TYP) {
327 final List<Name> idents = enumNamesFor((ClassSymbol)enumClass);
328 if (idents != null)
329 return new CompileTimeEnumMapping(idents);
330 }
331
332 // Map identifiers to ordinal values at runtime, and then switch on that
333 return enumSwitchMap.computeIfAbsent(enumClass, ec -> new RuntimeEnumMapping(pos, ec));
334 }
335
336 /** Generates a test value and corresponding cases for a switch on an enum type.
337 */
338 interface EnumMapping {
339
340 /** Given an expression for the enum value's ordinal, generate an expression for the switch statement.
341 */
342 JCExpression switchValue(JCExpression ordinalExpr);
343
344 /** Generate the switch statement case value corresponding to the given enum value.
345 */
346 JCLiteral caseValue(VarSymbol v);
347
348 default void translate() {
349 }
350 }
351
352 /** EnumMapping using compile-time constants. Only valid when compiling the enum class itself,
353 * because otherwise the ordinals we use could become obsolete if/when the enum class is recompiled.
354 */
355 class CompileTimeEnumMapping implements EnumMapping {
356
357 final List<Name> enumNames;
358
359 CompileTimeEnumMapping(List<Name> enumNames) {
360 Assert.check(enumNames != null);
361 this.enumNames = enumNames;
362 }
363
364 @Override
365 public JCExpression switchValue(JCExpression ordinalExpr) {
366 return ordinalExpr;
367 }
368
369 @Override
370 public JCLiteral caseValue(VarSymbol v) {
371 final int ordinal = enumNames.indexOf(v.name);
372 Assert.check(ordinal != -1);
373 return make.Literal(ordinal);
374 }
375 }
376
377 /** EnumMapping using run-time ordinal lookup.
378 *
379 * This builds a translation table to be used for enum switches.
380 *
381 * <p>For each enum that appears as the type of a switch
382 * expression, we maintain an EnumMapping to assist in the
383 * translation, as exemplified by the following example:
384 *
385 * <p>we translate
386 * <pre>
387 * switch(colorExpression) {
388 * case red: stmt1;
389 * case green: stmt2;
390 * }
391 * </pre>
392 * into
393 * <pre>
394 * switch(Outer$0.$EnumMap$Color[colorExpression.ordinal()]) {
395 * case 1: stmt1;
396 * case 2: stmt2
397 * }
398 * </pre>
399 * with the auxiliary table initialized as follows:
400 * <pre>
401 * class Outer$0 {
402 * synthetic final int[] $EnumMap$Color = new int[Color.values().length];
403 * static {
404 * try { $EnumMap$Color[red.ordinal()] = 1; } catch (NoSuchFieldError ex) {}
405 * try { $EnumMap$Color[green.ordinal()] = 2; } catch (NoSuchFieldError ex) {}
406 * }
407 * }
408 * </pre>
409 * class EnumMapping provides mapping data and support methods for this translation.
410 */
411 class RuntimeEnumMapping implements EnumMapping {
412 RuntimeEnumMapping(DiagnosticPosition pos, TypeSymbol forEnum) {
413 this.forEnum = forEnum;
414 this.values = new LinkedHashMap<>();
415 this.pos = pos;
416 Name varName = names
417 .fromString(target.syntheticNameChar() +
418 "SwitchMap" +
419 target.syntheticNameChar() +
420 ClassWriter.externalize(forEnum.type.tsym.flatName().toString())
421 .replace('/', '.')
422 .replace('.', target.syntheticNameChar()));
423 ClassSymbol outerCacheClass = outerCacheClass();
424 this.mapVar = new VarSymbol(STATIC | SYNTHETIC | FINAL,
425 varName,
426 new ArrayType(syms.intType, syms.arrayClass),
427 outerCacheClass);
428 enterSynthetic(pos, mapVar, outerCacheClass.members());
429 }
430
431 DiagnosticPosition pos = null;
432
433 // the next value to use
434 int next = 1; // 0 (unused map elements) go to the default label
435
436 // the enum for which this is a map
437 final TypeSymbol forEnum;
438
439 // the field containing the map
440 final VarSymbol mapVar;
441
442 // the mapped values
443 final Map<VarSymbol,Integer> values;
444
445 @Override
446 public JCExpression switchValue(JCExpression ordinalExpr) {
447 return make.Indexed(mapVar, ordinalExpr);
448 }
449
450 @Override
451 public JCLiteral caseValue(VarSymbol v) {
452 Integer result = values.get(v);
453 if (result == null)
454 values.put(v, result = next++);
455 return make.Literal(result);
456 }
457
458 // generate the field initializer for the map
459 @Override
460 public void translate() {
461 boolean prevAllowProtectedAccess = attrEnv.info.allowProtectedAccess;
462 try {
463 make.at(pos.getStartPosition());
464 attrEnv.info.allowProtectedAccess = true;
465 JCClassDecl owner = classDef((ClassSymbol)mapVar.owner);
466
467 // synthetic static final int[] $SwitchMap$Color = new int[Color.values().length];
468 MethodSymbol valuesMethod = lookupMethod(pos,
469 names.values,
470 forEnum.type,
471 List.nil());
472 JCExpression size = make // Color.values().length
473 .Select(make.App(make.QualIdent(valuesMethod)),
474 syms.lengthVar);
475 JCExpression mapVarInit = make
476 .NewArray(make.Type(syms.intType), List.of(size), null)
477 .setType(new ArrayType(syms.intType, syms.arrayClass));
478
479 // try { $SwitchMap$Color[red.ordinal()] = 1; } catch (java.lang.NoSuchFieldError ex) {}
480 ListBuffer<JCStatement> stmts = new ListBuffer<>();
481 Symbol ordinalMethod = lookupMethod(pos,
482 names.ordinal,
483 forEnum.type,
484 List.nil());
485 List<JCCatch> catcher = List.<JCCatch>nil()
486 .prepend(make.Catch(make.VarDef(new VarSymbol(PARAMETER, names.ex,
487 syms.noSuchFieldErrorType,
488 syms.noSymbol),
489 null),
490 make.Block(0, List.nil())));
491 for (Map.Entry<VarSymbol,Integer> e : values.entrySet()) {
492 VarSymbol enumerator = e.getKey();
493 Integer mappedValue = e.getValue();
494 JCExpression assign = make
495 .Assign(make.Indexed(mapVar,
496 make.App(make.Select(make.QualIdent(enumerator),
497 ordinalMethod))),
498 make.Literal(mappedValue))
499 .setType(syms.intType);
500 JCStatement exec = make.Exec(assign);
501 JCStatement _try = make.Try(make.Block(0, List.of(exec)), catcher, null);
502 stmts.append(_try);
503 }
504
505 owner.defs = owner.defs
506 .prepend(make.Block(STATIC, stmts.toList()))
507 .prepend(make.VarDef(mapVar, mapVarInit));
508 } finally {
509 attrEnv.info.allowProtectedAccess = prevAllowProtectedAccess;
510 }
511 }
512 }
513
514
515 /* ************************************************************************
516 * Tree building blocks
517 *************************************************************************/
518
519 /** Equivalent to make.at(pos.getStartPosition()) with side effect of caching
520 * pos as make_pos, for use in diagnostics.
521 **/
522 TreeMaker make_at(DiagnosticPosition pos) {
523 make_pos = pos;
524 return make.at(pos);
525 }
526
527 /** Make an attributed tree representing a literal. This will be an
528 * Ident node in the case of boolean literals, a Literal node in all
529 * other cases.
530 * @param type The literal's type.
531 * @param value The literal's value.
532 */
533 JCExpression makeLit(Type type, Object value) {
534 return make.Literal(type.getTag(), value).setType(type.constType(value));
535 }
536
537 /** Make an attributed tree representing null.
538 */
539 JCExpression makeNull() {
540 return makeLit(syms.botType, null);
541 }
542
543 /** Make an attributed class instance creation expression.
544 * @param ctype The class type.
545 * @param args The constructor arguments.
546 */
547 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
548 JCNewClass tree = make.NewClass(null,
549 null, make.QualIdent(ctype.tsym), args, null);
550 tree.constructor = rs.resolveConstructor(
551 make_pos, attrEnv, ctype, TreeInfo.types(args), List.nil());
552 tree.type = ctype;
553 return tree;
554 }
555
556 /** Make an attributed unary expression.
557 * @param optag The operators tree tag.
558 * @param arg The operator's argument.
559 */
560 JCUnary makeUnary(JCTree.Tag optag, JCExpression arg) {
561 JCUnary tree = make.Unary(optag, arg);
562 tree.operator = operators.resolveUnary(tree, optag, arg.type);
563 tree.type = tree.operator.type.getReturnType();
564 return tree;
565 }
566
567 /** Make an attributed binary expression.
568 * @param optag The operators tree tag.
569 * @param lhs The operator's left argument.
570 * @param rhs The operator's right argument.
571 */
572 JCBinary makeBinary(JCTree.Tag optag, JCExpression lhs, JCExpression rhs) {
573 JCBinary tree = make.Binary(optag, lhs, rhs);
574 tree.operator = operators.resolveBinary(tree, optag, lhs.type, rhs.type);
575 tree.type = tree.operator.type.getReturnType();
576 return tree;
577 }
578
579 /** Make an attributed assignop expression.
580 * @param optag The operators tree tag.
581 * @param lhs The operator's left argument.
582 * @param rhs The operator's right argument.
583 */
584 JCAssignOp makeAssignop(JCTree.Tag optag, JCTree lhs, JCTree rhs) {
585 JCAssignOp tree = make.Assignop(optag, lhs, rhs);
586 tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), lhs.type, rhs.type);
587 tree.type = lhs.type;
588 return tree;
589 }
590
591 /** Convert tree into string object, unless it has already a
592 * reference type..
593 */
594 JCExpression makeString(JCExpression tree) {
595 if (!tree.type.isPrimitiveOrVoid()) {
596 return tree;
597 } else {
598 Symbol valueOfSym = lookupMethod(tree.pos(),
599 names.valueOf,
600 syms.stringType,
601 List.of(tree.type));
602 return make.App(make.QualIdent(valueOfSym), List.of(tree));
603 }
604 }
605
606 /** Create an empty anonymous class definition and enter and complete
607 * its symbol. Return the class definition's symbol.
608 * and create
609 * @param flags The class symbol's flags
610 * @param owner The class symbol's owner
611 */
612 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner) {
613 return makeEmptyClass(flags, owner, null, true);
614 }
615
616 JCClassDecl makeEmptyClass(long flags, ClassSymbol owner, Name flatname,
617 boolean addToDefs) {
618 // Create class symbol.
619 ClassSymbol c = syms.defineClass(names.empty, owner);
620 if (flatname != null) {
621 c.flatname = flatname;
622 } else {
623 c.flatname = chk.localClassName(c);
624 }
625 c.sourcefile = owner.sourcefile;
626 c.completer = Completer.NULL_COMPLETER;
627 c.members_field = WriteableScope.create(c);
628 c.flags_field = flags;
629 ClassType ctype = (ClassType) c.type;
630 ctype.supertype_field = syms.objectType;
631 ctype.interfaces_field = List.nil();
632
633 JCClassDecl odef = classDef(owner);
634
635 // Enter class symbol in owner scope and compiled table.
636 enterSynthetic(odef.pos(), c, owner.members());
637 chk.putCompiled(c);
638
639 // Create class definition tree.
640 JCClassDecl cdef = make.ClassDef(
641 make.Modifiers(flags), names.empty,
642 List.nil(),
643 null, List.nil(), List.nil());
644 cdef.sym = c;
645 cdef.type = c.type;
646
647 // Append class definition tree to owner's definitions.
648 if (addToDefs) odef.defs = odef.defs.prepend(cdef);
649 return cdef;
650 }
651
652 /* ************************************************************************
653 * Symbol manipulation utilities
654 *************************************************************************/
655
656 /** Enter a synthetic symbol in a given scope, but complain if there was already one there.
657 * @param pos Position for error reporting.
658 * @param sym The symbol.
659 * @param s The scope.
660 */
661 private void enterSynthetic(DiagnosticPosition pos, Symbol sym, WriteableScope s) {
662 s.enter(sym);
663 }
664
665 /** Create a fresh synthetic name within a given scope - the unique name is
666 * obtained by appending '$' chars at the end of the name until no match
667 * is found.
668 *
669 * @param name base name
670 * @param s scope in which the name has to be unique
671 * @return fresh synthetic name
672 */
673 private Name makeSyntheticName(Name name, Scope s) {
674 do {
675 name = name.append(
676 target.syntheticNameChar(),
677 names.empty);
678 } while (lookupSynthetic(name, s) != null);
679 return name;
680 }
681
682 /** Check whether synthetic symbols generated during lowering conflict
683 * with user-defined symbols.
684 *
685 * @param translatedTrees lowered class trees
686 */
687 void checkConflicts(List<JCTree> translatedTrees) {
688 for (JCTree t : translatedTrees) {
689 t.accept(conflictsChecker);
690 }
691 }
692
693 JCTree.Visitor conflictsChecker = new TreeScanner() {
694
695 TypeSymbol currentClass;
696
697 @Override
698 public void visitMethodDef(JCMethodDecl that) {
699 checkConflicts(that.pos(), that.sym, currentClass);
700 super.visitMethodDef(that);
701 }
702
703 @Override
704 public void visitVarDef(JCVariableDecl that) {
705 if (that.sym.owner.kind == TYP) {
706 checkConflicts(that.pos(), that.sym, currentClass);
707 }
708 super.visitVarDef(that);
709 }
710
711 @Override
712 public void visitClassDef(JCClassDecl that) {
713 TypeSymbol prevCurrentClass = currentClass;
714 currentClass = that.sym;
715 try {
716 super.visitClassDef(that);
717 }
718 finally {
719 currentClass = prevCurrentClass;
720 }
721 }
722
723 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
724 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
725 for (Symbol sym2 : ct.tsym.members().getSymbolsByName(sym.name, NON_RECURSIVE)) {
726 // VM allows methods and variables with differing types
727 if (sym.kind == sym2.kind &&
728 types.isSameType(types.erasure(sym.type), types.erasure(sym2.type)) &&
729 sym != sym2 &&
730 (sym.flags() & Flags.SYNTHETIC) != (sym2.flags() & Flags.SYNTHETIC) &&
731 (sym.flags() & BRIDGE) == 0 && (sym2.flags() & BRIDGE) == 0) {
732 syntheticError(pos, (sym2.flags() & SYNTHETIC) == 0 ? sym2 : sym);
733 return;
734 }
735 }
736 }
737 }
738
739 /** Report a conflict between a user symbol and a synthetic symbol.
740 */
741 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
742 if (!sym.type.isErroneous()) {
743 log.error(pos, Errors.CannotGenerateClass(sym.location(), Fragments.SyntheticNameConflict(sym, sym.location())));
744 }
745 }
746 };
747
748 /** Look up a synthetic name in a given scope.
749 * @param s The scope.
750 * @param name The name.
751 */
752 private Symbol lookupSynthetic(Name name, Scope s) {
753 Symbol sym = s.findFirst(name);
754 return (sym==null || (sym.flags()&SYNTHETIC)==0) ? null : sym;
755 }
756
757 /** Look up a method in a given scope.
758 */
759 private MethodSymbol lookupMethod(DiagnosticPosition pos, Name name, Type qual, List<Type> args) {
760 return rs.resolveInternalMethod(pos, attrEnv, qual, name, args, List.nil());
761 }
762
763 /** Anon inner classes are used as access constructor tags.
764 * accessConstructorTag will use an existing anon class if one is available,
765 * and synthesize a class (with makeEmptyClass) if one is not available.
766 * However, there is a small possibility that an existing class will not
767 * be generated as expected if it is inside a conditional with a constant
768 * expression. If that is found to be the case, create an empty class tree here.
769 */
770 private void checkAccessConstructorTags() {
771 for (List<ClassSymbol> l = accessConstrTags; l.nonEmpty(); l = l.tail) {
772 ClassSymbol c = l.head;
773 if (isTranslatedClassAvailable(c))
774 continue;
775 // Create class definition tree.
776 // IDENTITY_TYPE will be interpreted as ACC_SUPER for older class files so we are fine
777 JCClassDecl cdec = makeEmptyClass(STATIC | SYNTHETIC | IDENTITY_TYPE,
778 c.outermostClass(), c.flatname, false);
779 swapAccessConstructorTag(c, cdec.sym);
780 translated.append(cdec);
781 }
782 }
783 // where
784 private boolean isTranslatedClassAvailable(ClassSymbol c) {
785 for (JCTree tree: translated) {
786 if (tree.hasTag(CLASSDEF)
787 && ((JCClassDecl) tree).sym == c) {
788 return true;
789 }
790 }
791 return false;
792 }
793
794 void swapAccessConstructorTag(ClassSymbol oldCTag, ClassSymbol newCTag) {
795 for (MethodSymbol methodSymbol : accessConstrs.values()) {
796 Assert.check(methodSymbol.type.hasTag(METHOD));
797 MethodType oldMethodType =
798 (MethodType)methodSymbol.type;
799 if (oldMethodType.argtypes.head.tsym == oldCTag)
800 methodSymbol.type =
801 types.createMethodTypeWithParameters(oldMethodType,
802 oldMethodType.getParameterTypes().tail
803 .prepend(newCTag.erasure(types)));
804 }
805 }
806
807 /* ************************************************************************
808 * Access methods
809 *************************************************************************/
810
811 /** A mapping from symbols to their access numbers.
812 */
813 private Map<Symbol,Integer> accessNums;
814
815 /** A mapping from symbols to an array of access symbols, indexed by
816 * access code.
817 */
818 private Map<Symbol,MethodSymbol[]> accessSyms;
819
820 /** A mapping from (constructor) symbols to access constructor symbols.
821 */
822 private Map<Symbol,MethodSymbol> accessConstrs;
823
824 /** A list of all class symbols used for access constructor tags.
825 */
826 private List<ClassSymbol> accessConstrTags;
827
828 /** A queue for all accessed symbols.
829 */
830 private ListBuffer<Symbol> accessed;
831
832 /** return access code for identifier,
833 * @param tree The tree representing the identifier use.
834 * @param enclOp The closest enclosing operation node of tree,
835 * null if tree is not a subtree of an operation.
836 */
837 private static int accessCode(JCTree tree, JCTree enclOp) {
838 if (enclOp == null)
839 return AccessCode.DEREF.code;
840 else if (enclOp.hasTag(ASSIGN) &&
841 tree == TreeInfo.skipParens(((JCAssign) enclOp).lhs))
842 return AccessCode.ASSIGN.code;
843 else if ((enclOp.getTag().isIncOrDecUnaryOp() || enclOp.getTag().isAssignop()) &&
844 tree == TreeInfo.skipParens(((JCOperatorExpression) enclOp).getOperand(LEFT)))
845 return (((JCOperatorExpression) enclOp).operator).getAccessCode(enclOp.getTag());
846 else
847 return AccessCode.DEREF.code;
848 }
849
850 /** Return binary operator that corresponds to given access code.
851 */
852 private OperatorSymbol binaryAccessOperator(int acode, Tag tag) {
853 return operators.lookupBinaryOp(op -> op.getAccessCode(tag) == acode);
854 }
855
856 /** Return tree tag for assignment operation corresponding
857 * to given binary operator.
858 */
859 private static JCTree.Tag treeTag(OperatorSymbol operator) {
860 switch (operator.opcode) {
861 case ByteCodes.ior: case ByteCodes.lor:
862 return BITOR_ASG;
863 case ByteCodes.ixor: case ByteCodes.lxor:
864 return BITXOR_ASG;
865 case ByteCodes.iand: case ByteCodes.land:
866 return BITAND_ASG;
867 case ByteCodes.ishl: case ByteCodes.lshl:
868 case ByteCodes.ishll: case ByteCodes.lshll:
869 return SL_ASG;
870 case ByteCodes.ishr: case ByteCodes.lshr:
871 case ByteCodes.ishrl: case ByteCodes.lshrl:
872 return SR_ASG;
873 case ByteCodes.iushr: case ByteCodes.lushr:
874 case ByteCodes.iushrl: case ByteCodes.lushrl:
875 return USR_ASG;
876 case ByteCodes.iadd: case ByteCodes.ladd:
877 case ByteCodes.fadd: case ByteCodes.dadd:
878 case ByteCodes.string_add:
879 return PLUS_ASG;
880 case ByteCodes.isub: case ByteCodes.lsub:
881 case ByteCodes.fsub: case ByteCodes.dsub:
882 return MINUS_ASG;
883 case ByteCodes.imul: case ByteCodes.lmul:
884 case ByteCodes.fmul: case ByteCodes.dmul:
885 return MUL_ASG;
886 case ByteCodes.idiv: case ByteCodes.ldiv:
887 case ByteCodes.fdiv: case ByteCodes.ddiv:
888 return DIV_ASG;
889 case ByteCodes.imod: case ByteCodes.lmod:
890 case ByteCodes.fmod: case ByteCodes.dmod:
891 return MOD_ASG;
892 default:
893 throw new AssertionError();
894 }
895 }
896
897 /** The name of the access method with number `anum' and access code `acode'.
898 */
899 Name accessName(int anum, int acode) {
900 return names.fromString(
901 "access" + target.syntheticNameChar() + anum + acode / 10 + acode % 10);
902 }
903
904 /** Return access symbol for a private or protected symbol from an inner class.
905 * @param sym The accessed private symbol.
906 * @param tree The accessing tree.
907 * @param enclOp The closest enclosing operation node of tree,
908 * null if tree is not a subtree of an operation.
909 * @param protAccess Is access to a protected symbol in another
910 * package?
911 * @param refSuper Is access via a (qualified) C.super?
912 */
913 MethodSymbol accessSymbol(Symbol sym, JCTree tree, JCTree enclOp,
914 boolean protAccess, boolean refSuper) {
915 ClassSymbol accOwner = refSuper && protAccess
916 // For access via qualified super (T.super.x), place the
917 // access symbol on T.
918 ? (ClassSymbol)((JCFieldAccess) tree).selected.type.tsym
919 // Otherwise pretend that the owner of an accessed
920 // protected symbol is the enclosing class of the current
921 // class which is a subclass of the symbol's owner.
922 : accessClass(sym, protAccess, tree);
923
924 Symbol vsym = sym;
925 if (sym.owner != accOwner) {
926 vsym = sym.clone(accOwner);
927 actualSymbols.put(vsym, sym);
928 }
929
930 Integer anum // The access number of the access method.
931 = accessNums.get(vsym);
932 if (anum == null) {
933 anum = accessed.length();
934 accessNums.put(vsym, anum);
935 accessSyms.put(vsym, new MethodSymbol[AccessCode.numberOfAccessCodes]);
936 accessed.append(vsym);
937 // System.out.println("accessing " + vsym + " in " + vsym.location());
938 }
939
940 int acode; // The access code of the access method.
941 List<Type> argtypes; // The argument types of the access method.
942 Type restype; // The result type of the access method.
943 List<Type> thrown; // The thrown exceptions of the access method.
944 switch (vsym.kind) {
945 case VAR:
946 acode = accessCode(tree, enclOp);
947 if (acode >= AccessCode.FIRSTASGOP.code) {
948 OperatorSymbol operator = binaryAccessOperator(acode, enclOp.getTag());
949 if (operator.opcode == string_add)
950 argtypes = List.of(syms.objectType);
951 else
952 argtypes = operator.type.getParameterTypes().tail;
953 } else if (acode == AccessCode.ASSIGN.code)
954 argtypes = List.of(vsym.erasure(types));
955 else
956 argtypes = List.nil();
957 restype = vsym.erasure(types);
958 thrown = List.nil();
959 break;
960 case MTH:
961 acode = AccessCode.DEREF.code;
962 argtypes = vsym.erasure(types).getParameterTypes();
963 restype = vsym.erasure(types).getReturnType();
964 thrown = vsym.type.getThrownTypes();
965 break;
966 default:
967 throw new AssertionError();
968 }
969
970 // For references via qualified super, increment acode by one,
971 // making it odd.
972 if (protAccess && refSuper) acode++;
973
974 // Instance access methods get instance as first parameter.
975 // For protected symbols this needs to be the instance as a member
976 // of the type containing the accessed symbol, not the class
977 // containing the access method.
978 if ((vsym.flags() & STATIC) == 0) {
979 argtypes = argtypes.prepend(vsym.owner.erasure(types));
980 }
981 MethodSymbol[] accessors = accessSyms.get(vsym);
982 MethodSymbol accessor = accessors[acode];
983 if (accessor == null) {
984 accessor = new MethodSymbol(
985 STATIC | SYNTHETIC | (accOwner.isInterface() ? PUBLIC : 0),
986 accessName(anum.intValue(), acode),
987 new MethodType(argtypes, restype, thrown, syms.methodClass),
988 accOwner);
989 enterSynthetic(tree.pos(), accessor, accOwner.members());
990 accessors[acode] = accessor;
991 }
992 return accessor;
993 }
994
995 /** The qualifier to be used for accessing a symbol in an outer class.
996 * This is either C.sym or C.this.sym, depending on whether or not
997 * sym is static.
998 * @param sym The accessed symbol.
999 */
1000 JCExpression accessBase(DiagnosticPosition pos, Symbol sym) {
1001 return (sym.flags() & STATIC) != 0
1002 ? access(make.at(pos.getStartPosition()).QualIdent(sym.owner))
1003 : makeOwnerThis(pos, sym, true);
1004 }
1005
1006 /** Do we need an access method to reference private symbol?
1007 */
1008 boolean needsPrivateAccess(Symbol sym) {
1009 if (target.hasNestmateAccess()) {
1010 return false;
1011 }
1012 if ((sym.flags() & PRIVATE) == 0 || sym.owner == currentClass) {
1013 return false;
1014 } else if (sym.name == names.init && sym.owner.isDirectlyOrIndirectlyLocal()) {
1015 // private constructor in local class: relax protection
1016 sym.flags_field &= ~PRIVATE;
1017 return false;
1018 } else {
1019 return true;
1020 }
1021 }
1022
1023 /** Do we need an access method to reference symbol in other package?
1024 */
1025 boolean needsProtectedAccess(Symbol sym, JCTree tree) {
1026 if (disableProtectedAccessors) return false;
1027 if ((sym.flags() & PROTECTED) == 0 ||
1028 sym.owner.owner == currentClass.owner || // fast special case
1029 sym.packge() == currentClass.packge())
1030 return false;
1031 if (!currentClass.isSubClass(sym.owner, types))
1032 return true;
1033 if ((sym.flags() & STATIC) != 0 ||
1034 !tree.hasTag(SELECT) ||
1035 TreeInfo.name(((JCFieldAccess) tree).selected) == names._super)
1036 return false;
1037 return !((JCFieldAccess) tree).selected.type.tsym.isSubClass(currentClass, types);
1038 }
1039
1040 /** The class in which an access method for given symbol goes.
1041 * @param sym The access symbol
1042 * @param protAccess Is access to a protected symbol in another
1043 * package?
1044 */
1045 ClassSymbol accessClass(Symbol sym, boolean protAccess, JCTree tree) {
1046 if (protAccess) {
1047 Symbol qualifier = null;
1048 ClassSymbol c = currentClass;
1049 if (tree.hasTag(SELECT) && (sym.flags() & STATIC) == 0) {
1050 qualifier = ((JCFieldAccess) tree).selected.type.tsym;
1051 while (!qualifier.isSubClass(c, types)) {
1052 c = c.owner.enclClass();
1053 }
1054 return c;
1055 } else {
1056 while (!c.isSubClass(sym.owner, types)) {
1057 c = c.owner.enclClass();
1058 }
1059 }
1060 return c;
1061 } else {
1062 // the symbol is private
1063 return sym.owner.enclClass();
1064 }
1065 }
1066
1067 private boolean noClassDefIn(JCTree tree) {
1068 var scanner = new TreeScanner() {
1069 boolean noClassDef = true;
1070 @Override
1071 public void visitClassDef(JCClassDecl tree) {
1072 noClassDef = false;
1073 }
1074 };
1075 scanner.scan(tree);
1076 return scanner.noClassDef;
1077 }
1078
1079 private void addPrunedInfo(JCTree tree) {
1080 List<JCTree> infoList = prunedTree.get(currentClass);
1081 infoList = (infoList == null) ? List.of(tree) : infoList.prepend(tree);
1082 prunedTree.put(currentClass, infoList);
1083 }
1084
1085 /** Ensure that identifier is accessible, return tree accessing the identifier.
1086 * @param sym The accessed symbol.
1087 * @param tree The tree referring to the symbol.
1088 * @param enclOp The closest enclosing operation node of tree,
1089 * null if tree is not a subtree of an operation.
1090 * @param refSuper Is access via a (qualified) C.super?
1091 */
1092 JCExpression access(Symbol sym, JCExpression tree, JCExpression enclOp, boolean refSuper) {
1093 // Access a free variable via its proxy, or its proxy's proxy
1094 while (sym.kind == VAR && sym.owner.kind == MTH &&
1095 sym.owner.enclClass() != currentClass) {
1096 // A constant is replaced by its constant value.
1097 Object cv = ((VarSymbol)sym).getConstValue();
1098 if (cv != null) {
1099 make.at(tree.pos);
1100 return makeLit(sym.type, cv);
1101 }
1102 // Otherwise replace the variable by its proxy.
1103 sym = proxies.get(sym);
1104 Assert.check(sym != null && (sym.flags_field & FINAL) != 0);
1105 tree = make.at(tree.pos).Ident(sym);
1106 }
1107 JCExpression base = (tree.hasTag(SELECT)) ? ((JCFieldAccess) tree).selected : null;
1108 switch (sym.kind) {
1109 case TYP:
1110 if (sym.owner.kind != PCK) {
1111 // Convert type idents to
1112 // <flat name> or <package name> . <flat name>
1113 Name flatname = Convert.shortName(sym.flatName());
1114 while (base != null &&
1115 TreeInfo.symbol(base) != null &&
1116 TreeInfo.symbol(base).kind != PCK) {
1117 base = (base.hasTag(SELECT))
1118 ? ((JCFieldAccess) base).selected
1119 : null;
1120 }
1121 if (tree.hasTag(IDENT)) {
1122 ((JCIdent) tree).name = flatname;
1123 } else if (base == null) {
1124 tree = make.at(tree.pos).Ident(sym);
1125 ((JCIdent) tree).name = flatname;
1126 } else {
1127 ((JCFieldAccess) tree).selected = base;
1128 ((JCFieldAccess) tree).name = flatname;
1129 }
1130 }
1131 break;
1132 case MTH: case VAR:
1133 if (sym.owner.kind == TYP) {
1134
1135 // Access methods are required for
1136 // - private members,
1137 // - protected members in a superclass of an
1138 // enclosing class contained in another package.
1139 // - all non-private members accessed via a qualified super.
1140 boolean protAccess = refSuper && !needsPrivateAccess(sym)
1141 || needsProtectedAccess(sym, tree);
1142 boolean accReq = protAccess || needsPrivateAccess(sym);
1143
1144 // A base has to be supplied for
1145 // - simple identifiers accessing variables in outer classes.
1146 boolean baseReq =
1147 base == null &&
1148 sym.owner != syms.predefClass &&
1149 !sym.isMemberOf(currentClass, types);
1150
1151 if (accReq || baseReq) {
1152 make.at(tree.pos);
1153
1154 // Constants are replaced by their constant value.
1155 if (sym.kind == VAR) {
1156 Object cv = ((VarSymbol)sym).getConstValue();
1157 if (cv != null) {
1158 addPrunedInfo(tree);
1159 return makeLit(sym.type, cv);
1160 }
1161 }
1162
1163 // Private variables and methods are replaced by calls
1164 // to their access methods.
1165 if (accReq) {
1166 List<JCExpression> args = List.nil();
1167 if ((sym.flags() & STATIC) == 0) {
1168 // Instance access methods get instance
1169 // as first parameter.
1170 if (base == null)
1171 base = makeOwnerThis(tree.pos(), sym, true);
1172 args = args.prepend(base);
1173 base = null; // so we don't duplicate code
1174 }
1175 Symbol access = accessSymbol(sym, tree,
1176 enclOp, protAccess,
1177 refSuper);
1178 JCExpression receiver = make.Select(
1179 base != null ? base : make.QualIdent(access.owner),
1180 access);
1181 return make.App(receiver, args);
1182
1183 // Other accesses to members of outer classes get a
1184 // qualifier.
1185 } else if (baseReq) {
1186 return make.at(tree.pos).Select(
1187 accessBase(tree.pos(), sym), sym).setType(tree.type);
1188 }
1189 }
1190 }
1191 }
1192 return tree;
1193 }
1194
1195 /** Ensure that identifier is accessible, return tree accessing the identifier.
1196 * @param tree The identifier tree.
1197 */
1198 JCExpression access(JCExpression tree) {
1199 Symbol sym = TreeInfo.symbol(tree);
1200 return sym == null ? tree : access(sym, tree, null, false);
1201 }
1202
1203 /** Return access constructor for a private constructor,
1204 * or the constructor itself, if no access constructor is needed.
1205 * @param pos The position to report diagnostics, if any.
1206 * @param constr The private constructor.
1207 */
1208 Symbol accessConstructor(DiagnosticPosition pos, Symbol constr) {
1209 if (needsPrivateAccess(constr)) {
1210 ClassSymbol accOwner = constr.owner.enclClass();
1211 MethodSymbol aconstr = accessConstrs.get(constr);
1212 if (aconstr == null) {
1213 List<Type> argtypes = constr.type.getParameterTypes();
1214 if ((accOwner.flags_field & ENUM) != 0)
1215 argtypes = argtypes
1216 .prepend(syms.intType)
1217 .prepend(syms.stringType);
1218 aconstr = new MethodSymbol(
1219 SYNTHETIC,
1220 names.init,
1221 new MethodType(
1222 argtypes.append(
1223 accessConstructorTag().erasure(types)),
1224 constr.type.getReturnType(),
1225 constr.type.getThrownTypes(),
1226 syms.methodClass),
1227 accOwner);
1228 enterSynthetic(pos, aconstr, accOwner.members());
1229 accessConstrs.put(constr, aconstr);
1230 accessed.append(constr);
1231 }
1232 return aconstr;
1233 } else {
1234 return constr;
1235 }
1236 }
1237
1238 /** Return an anonymous class nested in this toplevel class.
1239 */
1240 ClassSymbol accessConstructorTag() {
1241 ClassSymbol topClass = currentClass.outermostClass();
1242 ModuleSymbol topModle = topClass.packge().modle;
1243 for (int i = 1; ; i++) {
1244 Name flatname = names.fromString("" + topClass.getQualifiedName() +
1245 target.syntheticNameChar() +
1246 i);
1247 ClassSymbol ctag = chk.getCompiled(topModle, flatname);
1248 if (ctag == null)
1249 // IDENTITY_TYPE will be interpreted as ACC_SUPER for older class files so we are fine
1250 ctag = makeEmptyClass(STATIC | SYNTHETIC | IDENTITY_TYPE, topClass).sym;
1251 else if (!ctag.isAnonymous())
1252 continue;
1253 // keep a record of all tags, to verify that all are generated as required
1254 accessConstrTags = accessConstrTags.prepend(ctag);
1255 return ctag;
1256 }
1257 }
1258
1259 /** Add all required access methods for a private symbol to enclosing class.
1260 * @param sym The symbol.
1261 */
1262 void makeAccessible(Symbol sym) {
1263 JCClassDecl cdef = classDef(sym.owner.enclClass());
1264 if (cdef == null) Assert.error("class def not found: " + sym + " in " + sym.owner);
1265 if (sym.name == names.init) {
1266 cdef.defs = cdef.defs.prepend(
1267 accessConstructorDef(cdef.pos, sym, accessConstrs.get(sym)));
1268 } else {
1269 MethodSymbol[] accessors = accessSyms.get(sym);
1270 for (int i = 0; i < AccessCode.numberOfAccessCodes; i++) {
1271 if (accessors[i] != null)
1272 cdef.defs = cdef.defs.prepend(
1273 accessDef(cdef.pos, sym, accessors[i], i));
1274 }
1275 }
1276 }
1277
1278 /** Construct definition of an access method.
1279 * @param pos The source code position of the definition.
1280 * @param vsym The private or protected symbol.
1281 * @param accessor The access method for the symbol.
1282 * @param acode The access code.
1283 */
1284 JCTree accessDef(int pos, Symbol vsym, MethodSymbol accessor, int acode) {
1285 // System.err.println("access " + vsym + " with " + accessor);//DEBUG
1286 currentClass = vsym.owner.enclClass();
1287 make.at(pos);
1288 JCMethodDecl md = make.MethodDef(accessor, null);
1289
1290 // Find actual symbol
1291 Symbol sym = actualSymbols.get(vsym);
1292 if (sym == null) sym = vsym;
1293
1294 JCExpression ref; // The tree referencing the private symbol.
1295 List<JCExpression> args; // Any additional arguments to be passed along.
1296 if ((sym.flags() & STATIC) != 0) {
1297 ref = make.Ident(sym);
1298 args = make.Idents(md.params);
1299 } else {
1300 JCExpression site = make.Ident(md.params.head);
1301 if (acode % 2 != 0) {
1302 //odd access codes represent qualified super accesses - need to
1303 //emit reference to the direct superclass, even if the referred
1304 //member is from an indirect superclass (JLS 13.1)
1305 site.setType(types.erasure(types.supertype(vsym.owner.enclClass().type)));
1306 }
1307 ref = make.Select(site, sym);
1308 args = make.Idents(md.params.tail);
1309 }
1310 JCStatement stat; // The statement accessing the private symbol.
1311 if (sym.kind == VAR) {
1312 // Normalize out all odd access codes by taking floor modulo 2:
1313 int acode1 = acode - (acode & 1);
1314
1315 JCExpression expr; // The access method's return value.
1316 AccessCode aCode = AccessCode.getFromCode(acode1);
1317 switch (aCode) {
1318 case DEREF:
1319 expr = ref;
1320 break;
1321 case ASSIGN:
1322 expr = make.Assign(ref, args.head);
1323 break;
1324 case PREINC: case POSTINC: case PREDEC: case POSTDEC:
1325 expr = makeUnary(aCode.tag, ref);
1326 break;
1327 default:
1328 expr = make.Assignop(
1329 treeTag(binaryAccessOperator(acode1, JCTree.Tag.NO_TAG)), ref, args.head);
1330 ((JCAssignOp) expr).operator = binaryAccessOperator(acode1, JCTree.Tag.NO_TAG);
1331 }
1332 stat = make.Return(expr.setType(sym.type));
1333 } else {
1334 stat = make.Call(make.App(ref, args));
1335 }
1336 md.body = make.Block(0, List.of(stat));
1337
1338 // Make sure all parameters, result types and thrown exceptions
1339 // are accessible.
1340 for (List<JCVariableDecl> l = md.params; l.nonEmpty(); l = l.tail)
1341 l.head.vartype = access(l.head.vartype);
1342 md.restype = access(md.restype);
1343 for (List<JCExpression> l = md.thrown; l.nonEmpty(); l = l.tail)
1344 l.head = access(l.head);
1345
1346 return md;
1347 }
1348
1349 /** Construct definition of an access constructor.
1350 * @param pos The source code position of the definition.
1351 * @param constr The private constructor.
1352 * @param accessor The access method for the constructor.
1353 */
1354 JCTree accessConstructorDef(int pos, Symbol constr, MethodSymbol accessor) {
1355 make.at(pos);
1356 JCMethodDecl md = make.MethodDef(accessor,
1357 accessor.externalType(types),
1358 null);
1359 JCIdent callee = make.Ident(names._this);
1360 callee.sym = constr;
1361 callee.type = constr.type;
1362 md.body =
1363 make.Block(0, List.of(
1364 make.Call(
1365 make.App(
1366 callee,
1367 make.Idents(md.params.reverse().tail.reverse())))));
1368 return md;
1369 }
1370
1371 /* ************************************************************************
1372 * Free variables proxies and this$n
1373 *************************************************************************/
1374
1375 /** A map which allows to retrieve the translated proxy variable for any given symbol of an
1376 * enclosing scope that is accessed (the accessed symbol could be the synthetic 'this$n' symbol).
1377 * Inside a constructor, the map temporarily overrides entries corresponding to proxies and any
1378 * 'this$n' symbols, where they represent the constructor parameters.
1379 */
1380 Map<Symbol, Symbol> proxies;
1381
1382 /** A scope containing all unnamed resource variables/saved
1383 * exception variables for translated TWR blocks
1384 */
1385 WriteableScope twrVars;
1386
1387 /** A stack containing the this$n field of the currently translated
1388 * classes (if needed) in innermost first order.
1389 * Inside a constructor, proxies and any this$n symbol are duplicated
1390 * in an additional innermost scope, where they represent the constructor
1391 * parameters.
1392 */
1393 List<VarSymbol> outerThisStack;
1394
1395 /** The name of a free variable proxy.
1396 */
1397 Name proxyName(Name name, int index) {
1398 Name proxyName = names.fromString("val" + target.syntheticNameChar() + name);
1399 if (index > 0) {
1400 proxyName = proxyName.append(names.fromString("" + target.syntheticNameChar() + index));
1401 }
1402 return proxyName;
1403 }
1404
1405 /** Proxy definitions for all free variables in given list, in reverse order.
1406 * @param pos The source code position of the definition.
1407 * @param freevars The free variables.
1408 * @param owner The class in which the definitions go.
1409 */
1410 List<JCVariableDecl> freevarDefs(int pos, List<VarSymbol> freevars, Symbol owner) {
1411 long strict = (allowValueClasses && owner.isValueClass()) ? STRICT : 0;
1412 return freevarDefs(pos, freevars, owner, LOCAL_CAPTURE_FIELD | strict);
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 if (owner.kind == TYP) {
1461 // Set NOOUTERTHIS for all synthetic outer instance variables, and unset
1462 // it when the variable is accessed. If the variable is never accessed,
1463 // we skip creating an outer instance field and saving the constructor
1464 // parameter to it.
1465 flags = flags | NOOUTERTHIS | OUTER_THIS_FIELD;
1466 }
1467 VarSymbol outerThis = new VarSymbol(flags, outerThisName(target, owner), target, owner);
1468 outerThisStack = outerThisStack.prepend(outerThis);
1469 return outerThis;
1470 }
1471
1472 private JCVariableDecl makeOuterThisVarDecl(int pos, VarSymbol sym) {
1473 JCVariableDecl vd = make.at(pos).VarDef(sym, null);
1474 vd.vartype = access(vd.vartype);
1475 return vd;
1476 }
1477
1478 /** Definition for this$n field.
1479 * @param pos The source code position of the definition.
1480 * @param owner The method in which the definition goes.
1481 */
1482 JCVariableDecl outerThisDef(int pos, MethodSymbol owner) {
1483 ClassSymbol c = owner.enclClass();
1484 boolean isMandated =
1485 // Anonymous constructors
1486 (owner.isConstructor() && owner.isAnonymous()) ||
1487 // Constructors of non-private inner member classes
1488 (owner.isConstructor() && c.isInner() &&
1489 !c.isPrivate() && !c.isStatic());
1490 long flags =
1491 FINAL | (isMandated ? MANDATED : SYNTHETIC) | PARAMETER;
1492 VarSymbol outerThis = makeOuterThisVarSymbol(owner, flags);
1493 owner.extraParams = owner.extraParams.prepend(outerThis);
1494 return makeOuterThisVarDecl(pos, outerThis);
1495 }
1496
1497 /** Definition for this$n field.
1498 * @param pos The source code position of the definition.
1499 * @param owner The class in which the definition goes.
1500 */
1501 JCVariableDecl outerThisDef(int pos, ClassSymbol owner) {
1502 long strict = (allowValueClasses && owner.isValueClass()) ? STRICT : 0;
1503 VarSymbol outerThis = makeOuterThisVarSymbol(owner, FINAL | SYNTHETIC | strict);
1504 return makeOuterThisVarDecl(pos, outerThis);
1505 }
1506
1507 /** Return a list of trees that load the free variables in given list,
1508 * in reverse order.
1509 * @param pos The source code position to be used for the trees.
1510 * @param freevars The list of free variables.
1511 */
1512 List<JCExpression> loadFreevars(DiagnosticPosition pos, List<VarSymbol> freevars) {
1513 List<JCExpression> args = List.nil();
1514 for (List<VarSymbol> l = freevars; l.nonEmpty(); l = l.tail)
1515 args = args.prepend(loadFreevar(pos, l.head));
1516 return args;
1517 }
1518 //where
1519 JCExpression loadFreevar(DiagnosticPosition pos, VarSymbol v) {
1520 return access(v, make.at(pos).Ident(v), null, false);
1521 }
1522
1523 /** Construct a tree simulating the expression {@code C.this}.
1524 * @param pos The source code position to be used for the tree.
1525 * @param c The qualifier class.
1526 */
1527 JCExpression makeThis(DiagnosticPosition pos, TypeSymbol c) {
1528 if (currentClass == c) {
1529 // in this case, `this' works fine
1530 return make.at(pos).This(c.erasure(types));
1531 } else {
1532 // need to go via this$n
1533 return makeOuterThis(pos, c);
1534 }
1535 }
1536
1537 /**
1538 * Optionally replace a try statement with the desugaring of a
1539 * try-with-resources statement. The canonical desugaring of
1540 *
1541 * try ResourceSpecification
1542 * Block
1543 *
1544 * is
1545 *
1546 * {
1547 * final VariableModifiers_minus_final R #resource = Expression;
1548 *
1549 * try ResourceSpecificationtail
1550 * Block
1551 * } body-only-finally {
1552 * if (#resource != null) //nullcheck skipped if Expression is provably non-null
1553 * #resource.close();
1554 * } catch (Throwable #primaryException) {
1555 * if (#resource != null) //nullcheck skipped if Expression is provably non-null
1556 * try {
1557 * #resource.close();
1558 * } catch (Throwable #suppressedException) {
1559 * #primaryException.addSuppressed(#suppressedException);
1560 * }
1561 * throw #primaryException;
1562 * }
1563 * }
1564 *
1565 * @param tree The try statement to inspect.
1566 * @return a desugared try-with-resources tree, or the original
1567 * try block if there are no resources to manage.
1568 */
1569 JCTree makeTwrTry(JCTry tree) {
1570 make_at(tree.pos());
1571 twrVars = twrVars.dup();
1572 JCBlock twrBlock = makeTwrBlock(tree.resources, tree.body, 0);
1573 if (tree.catchers.isEmpty() && tree.finalizer == null)
1574 result = translate(twrBlock);
1575 else
1576 result = translate(make.Try(twrBlock, tree.catchers, tree.finalizer));
1577 twrVars = twrVars.leave();
1578 return result;
1579 }
1580
1581 private JCBlock makeTwrBlock(List<JCTree> resources, JCBlock block, int depth) {
1582 if (resources.isEmpty())
1583 return block;
1584
1585 // Add resource declaration or expression to block statements
1586 ListBuffer<JCStatement> stats = new ListBuffer<>();
1587 JCTree resource = resources.head;
1588 JCExpression resourceUse;
1589 boolean resourceNonNull;
1590 if (resource instanceof JCVariableDecl variableDecl) {
1591 resourceUse = make.Ident(variableDecl.sym).setType(resource.type);
1592 resourceNonNull = variableDecl.init != null && TreeInfo.skipParens(variableDecl.init).hasTag(NEWCLASS);
1593 stats.add(variableDecl);
1594 } else {
1595 Assert.check(resource instanceof JCExpression);
1596 VarSymbol syntheticTwrVar =
1597 new VarSymbol(SYNTHETIC | FINAL,
1598 makeSyntheticName(names.fromString("twrVar" +
1599 depth), twrVars),
1600 (resource.type.hasTag(BOT)) ?
1601 syms.autoCloseableType : resource.type,
1602 currentMethodSym);
1603 twrVars.enter(syntheticTwrVar);
1604 JCVariableDecl syntheticTwrVarDecl =
1605 make.VarDef(syntheticTwrVar, (JCExpression)resource);
1606 resourceUse = (JCExpression)make.Ident(syntheticTwrVar);
1607 resourceNonNull = false;
1608 stats.add(syntheticTwrVarDecl);
1609 }
1610
1611 //create (semi-) finally block that will be copied into the main try body:
1612 int oldPos = make.pos;
1613 make.at(TreeInfo.endPos(block));
1614
1615 // if (#resource != null) { #resource.close(); }
1616 JCStatement bodyCloseStatement = makeResourceCloseInvocation(resourceUse);
1617
1618 if (!resourceNonNull) {
1619 bodyCloseStatement = make.If(makeNonNullCheck(resourceUse),
1620 bodyCloseStatement,
1621 null);
1622 }
1623
1624 JCBlock finallyClause = make.Block(BODY_ONLY_FINALIZE, List.of(bodyCloseStatement));
1625 make.at(oldPos);
1626
1627 // Create catch clause that saves exception, closes the resource and then rethrows the exception:
1628 VarSymbol primaryException =
1629 new VarSymbol(FINAL|SYNTHETIC,
1630 names.fromString("t" +
1631 target.syntheticNameChar()),
1632 syms.throwableType,
1633 currentMethodSym);
1634 JCVariableDecl primaryExceptionDecl = make.VarDef(primaryException, null);
1635
1636 // close resource:
1637 // try {
1638 // #resource.close();
1639 // } catch (Throwable #suppressedException) {
1640 // #primaryException.addSuppressed(#suppressedException);
1641 // }
1642 VarSymbol suppressedException =
1643 new VarSymbol(SYNTHETIC, make.paramName(2),
1644 syms.throwableType,
1645 currentMethodSym);
1646 JCStatement addSuppressedStatement =
1647 make.Exec(makeCall(make.Ident(primaryException),
1648 names.addSuppressed,
1649 List.of(make.Ident(suppressedException))));
1650 JCBlock closeResourceTryBlock =
1651 make.Block(0L, List.of(makeResourceCloseInvocation(resourceUse)));
1652 JCVariableDecl catchSuppressedDecl = make.VarDef(suppressedException, null);
1653 JCBlock catchSuppressedBlock = make.Block(0L, List.of(addSuppressedStatement));
1654 List<JCCatch> catchSuppressedClauses =
1655 List.of(make.Catch(catchSuppressedDecl, catchSuppressedBlock));
1656 JCTry closeResourceTry = make.Try(closeResourceTryBlock, catchSuppressedClauses, null);
1657 closeResourceTry.finallyCanCompleteNormally = true;
1658
1659 JCStatement exceptionalCloseStatement = closeResourceTry;
1660
1661 if (!resourceNonNull) {
1662 // if (#resource != null) { }
1663 exceptionalCloseStatement = make.If(makeNonNullCheck(resourceUse),
1664 exceptionalCloseStatement,
1665 null);
1666 }
1667
1668 JCStatement exceptionalRethrow = make.Throw(make.Ident(primaryException));
1669 JCBlock exceptionalCloseBlock = make.Block(0L, List.of(exceptionalCloseStatement, exceptionalRethrow));
1670 JCCatch exceptionalCatchClause = make.Catch(primaryExceptionDecl, exceptionalCloseBlock);
1671
1672 //create the main try statement with the close:
1673 JCTry outerTry = make.Try(makeTwrBlock(resources.tail, block, depth + 1),
1674 List.of(exceptionalCatchClause),
1675 finallyClause);
1676
1677 outerTry.finallyCanCompleteNormally = true;
1678 stats.add(outerTry);
1679
1680 JCBlock newBlock = make.Block(0L, stats.toList());
1681 return newBlock;
1682 }
1683
1684 private JCStatement makeResourceCloseInvocation(JCExpression resource) {
1685 // convert to AutoCloseable if needed
1686 if (types.asSuper(resource.type, syms.autoCloseableType.tsym) == null) {
1687 resource = convert(resource, syms.autoCloseableType);
1688 }
1689
1690 // create resource.close() method invocation
1691 JCExpression resourceClose = makeCall(resource,
1692 names.close,
1693 List.nil());
1694 return make.Exec(resourceClose);
1695 }
1696
1697 private JCExpression makeNonNullCheck(JCExpression expression) {
1698 return makeBinary(NE, expression, makeNull());
1699 }
1700
1701 /** Construct a tree that represents the outer instance
1702 * {@code C.this}. Never pick the current `this'.
1703 * @param pos The source code position to be used for the tree.
1704 * @param c The qualifier class.
1705 */
1706 JCExpression makeOuterThis(DiagnosticPosition pos, TypeSymbol c) {
1707 List<VarSymbol> ots = outerThisStack;
1708 if (ots.isEmpty()) {
1709 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1710 return makeNull();
1711 }
1712 VarSymbol ot = ots.head;
1713 JCExpression tree = access(make.at(pos).Ident(ot));
1714 ot.flags_field &= ~NOOUTERTHIS;
1715 TypeSymbol otc = ot.type.tsym;
1716 while (otc != c) {
1717 do {
1718 ots = ots.tail;
1719 if (ots.isEmpty()) {
1720 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1721 Assert.error(); // should have been caught in Attr
1722 return tree;
1723 }
1724 ot = ots.head;
1725 } while (ot.owner != otc);
1726 if (otc.owner.kind != PCK && !otc.hasOuterInstance()) {
1727 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1728 Assert.error(); // should have been caught in Attr
1729 return makeNull();
1730 }
1731 tree = access(make.at(pos).Select(tree, ot));
1732 ot.flags_field &= ~NOOUTERTHIS;
1733 otc = ot.type.tsym;
1734 }
1735 return tree;
1736 }
1737
1738 /** Construct a tree that represents the closest outer instance
1739 * {@code C.this} such that the given symbol is a member of C.
1740 * @param pos The source code position to be used for the tree.
1741 * @param sym The accessed symbol.
1742 * @param preciseMatch should we accept a type that is a subtype of
1743 * sym's owner, even if it doesn't contain sym
1744 * due to hiding, overriding, or non-inheritance
1745 * due to protection?
1746 */
1747 JCExpression makeOwnerThis(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1748 if (preciseMatch ? sym.isMemberOf(currentClass, types)
1749 : currentClass.isSubClass(sym.owner, types)) {
1750 // in this case, `this' works fine
1751 return make.at(pos).This(currentClass.erasure(types));
1752 } else {
1753 // need to go via this$n
1754 return makeOwnerThisN(pos, sym, preciseMatch);
1755 }
1756 }
1757
1758 /**
1759 * Similar to makeOwnerThis but will never pick "this".
1760 */
1761 JCExpression makeOwnerThisN(DiagnosticPosition pos, Symbol sym, boolean preciseMatch) {
1762 Symbol c = sym.owner;
1763 List<VarSymbol> ots = outerThisStack;
1764 if (ots.isEmpty()) {
1765 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1766 return makeNull();
1767 }
1768 VarSymbol ot = ots.head;
1769 JCExpression tree = access(make.at(pos).Ident(ot));
1770 ot.flags_field &= ~NOOUTERTHIS;
1771 TypeSymbol otc = ot.type.tsym;
1772 while (!(preciseMatch ? sym.isMemberOf(otc, types) : otc.isSubClass(sym.owner, types))) {
1773 do {
1774 ots = ots.tail;
1775 if (ots.isEmpty()) {
1776 log.error(pos, Errors.NoEnclInstanceOfTypeInScope(c));
1777 return tree;
1778 }
1779 ot = ots.head;
1780 } while (ot.owner != otc);
1781 tree = access(make.at(pos).Select(tree, ot));
1782 ot.flags_field &= ~NOOUTERTHIS;
1783 otc = ot.type.tsym;
1784 }
1785 return tree;
1786 }
1787
1788 /** Return tree simulating the assignment {@code this.name = name}, where
1789 * name is the name of a free variable.
1790 */
1791 JCStatement initField(int pos, Symbol rhs, Symbol lhs) {
1792 Assert.check(rhs.owner.kind == MTH);
1793 Assert.check(rhs.owner.owner == lhs.owner);
1794 make.at(pos);
1795 return
1796 make.Exec(
1797 make.Assign(
1798 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1799 make.Ident(rhs)).setType(lhs.erasure(types)));
1800 }
1801
1802 /**
1803 * Return tree simulating null checking outer this and/or assigning. This is
1804 * called when a null check is required (nullCheckOuterThis), or a synthetic
1805 * field is generated (stores).
1806 */
1807 JCStatement initOuterThis(int pos, VarSymbol rhs, boolean stores) {
1808 Assert.check(rhs.owner.kind == MTH);
1809 Assert.check(nullCheckOuterThis || stores); // One of the flags must be true
1810 make.at(pos);
1811 JCExpression expression = make.Ident(rhs);
1812 if (nullCheckOuterThis) {
1813 expression = attr.makeNullCheck(expression);
1814 }
1815 if (stores) {
1816 VarSymbol lhs = outerThisStack.head;
1817 Assert.check(rhs.owner.owner == lhs.owner);
1818 expression = make.Assign(
1819 make.Select(make.This(lhs.owner.erasure(types)), lhs),
1820 expression).setType(lhs.erasure(types));
1821 }
1822 return make.Exec(expression);
1823 }
1824
1825 /* ************************************************************************
1826 * Code for .class
1827 *************************************************************************/
1828
1829 /** Return the symbol of a class to contain a cache of
1830 * compiler-generated statics such as class$ and the
1831 * $assertionsDisabled flag. We create an anonymous nested class
1832 * (unless one already exists) and return its symbol. However,
1833 * for backward compatibility in 1.4 and earlier we use the
1834 * top-level class itself.
1835 */
1836 private ClassSymbol outerCacheClass() {
1837 ClassSymbol clazz = outermostClassDef.sym;
1838 Scope s = clazz.members();
1839 for (Symbol sym : s.getSymbols(NON_RECURSIVE))
1840 if (sym.kind == TYP &&
1841 sym.name == names.empty &&
1842 (sym.flags() & INTERFACE) == 0) return (ClassSymbol) sym;
1843 // IDENTITY_TYPE will be interpreted as ACC_SUPER for older class files so we are fine
1844 return makeEmptyClass(STATIC | SYNTHETIC | IDENTITY_TYPE, clazz).sym;
1845 }
1846
1847 /** Create an attributed tree of the form left.name(). */
1848 private JCMethodInvocation makeCall(JCExpression left, Name name, List<JCExpression> args) {
1849 Assert.checkNonNull(left.type);
1850 Symbol funcsym = lookupMethod(make_pos, name, left.type,
1851 TreeInfo.types(args));
1852 return make.App(make.Select(left, funcsym), args);
1853 }
1854
1855 /** The tree simulating a T.class expression.
1856 * @param clazz The tree identifying type T.
1857 */
1858 private JCExpression classOf(JCTree clazz) {
1859 return classOfType(clazz.type, clazz.pos());
1860 }
1861
1862 private JCExpression classOfType(Type type, DiagnosticPosition pos) {
1863 switch (type.getTag()) {
1864 case BYTE: case SHORT: case CHAR: case INT: case LONG: case FLOAT:
1865 case DOUBLE: case BOOLEAN: case VOID:
1866 // replace with <BoxedClass>.TYPE
1867 ClassSymbol c = types.boxedClass(type);
1868 Symbol typeSym =
1869 rs.accessBase(
1870 rs.findIdentInType(pos, attrEnv, c.type, names.TYPE, KindSelector.VAR, null),
1871 pos, c.type, names.TYPE, true);
1872 if (typeSym.kind == VAR)
1873 ((VarSymbol)typeSym).getConstValue(); // ensure initializer is evaluated
1874 return make.QualIdent(typeSym);
1875 case CLASS: case ARRAY:
1876 VarSymbol sym = new VarSymbol(
1877 STATIC | PUBLIC | FINAL, names._class,
1878 syms.classType, type.tsym);
1879 return make_at(pos).Select(make.Type(type), sym);
1880 default:
1881 throw new AssertionError();
1882 }
1883 }
1884
1885 /* ************************************************************************
1886 * Code for enabling/disabling assertions.
1887 *************************************************************************/
1888
1889 private ClassSymbol assertionsDisabledClassCache;
1890
1891 /**Used to create an auxiliary class to hold $assertionsDisabled for interfaces.
1892 */
1893 private ClassSymbol assertionsDisabledClass() {
1894 if (assertionsDisabledClassCache != null) return assertionsDisabledClassCache;
1895
1896 // IDENTITY_TYPE will be interpreted as ACC_SUPER for older class files so we are fine
1897 assertionsDisabledClassCache = makeEmptyClass(STATIC | SYNTHETIC | IDENTITY_TYPE, outermostClassDef.sym).sym;
1898
1899 return assertionsDisabledClassCache;
1900 }
1901
1902 // This code is not particularly robust if the user has
1903 // previously declared a member named '$assertionsDisabled'.
1904 // The same faulty idiom also appears in the translation of
1905 // class literals above. We should report an error if a
1906 // previous declaration is not synthetic.
1907
1908 private JCExpression assertFlagTest(DiagnosticPosition pos) {
1909 // Outermost class may be either true class or an interface.
1910 ClassSymbol outermostClass = outermostClassDef.sym;
1911
1912 //only classes can hold a non-public field, look for a usable one:
1913 ClassSymbol container = !currentClass.isInterface() ? currentClass :
1914 assertionsDisabledClass();
1915
1916 VarSymbol assertDisabledSym =
1917 (VarSymbol)lookupSynthetic(dollarAssertionsDisabled,
1918 container.members());
1919 if (assertDisabledSym == null) {
1920 assertDisabledSym =
1921 new VarSymbol(STATIC | FINAL | SYNTHETIC,
1922 dollarAssertionsDisabled,
1923 syms.booleanType,
1924 container);
1925 enterSynthetic(pos, assertDisabledSym, container.members());
1926 Symbol desiredAssertionStatusSym = lookupMethod(pos,
1927 names.desiredAssertionStatus,
1928 types.erasure(syms.classType),
1929 List.nil());
1930 JCClassDecl containerDef = classDef(container);
1931 make_at(containerDef.pos());
1932 JCExpression notStatus = makeUnary(NOT, make.App(make.Select(
1933 classOfType(types.erasure(outermostClass.type),
1934 containerDef.pos()),
1935 desiredAssertionStatusSym)));
1936 JCVariableDecl assertDisabledDef = make.VarDef(assertDisabledSym,
1937 notStatus);
1938 containerDef.defs = containerDef.defs.prepend(assertDisabledDef);
1939
1940 if (currentClass.isInterface()) {
1941 //need to load the assertions enabled/disabled state while
1942 //initializing the interface:
1943 JCClassDecl currentClassDef = classDef(currentClass);
1944 make_at(currentClassDef.pos());
1945 JCStatement dummy = make.If(make.QualIdent(assertDisabledSym), make.Skip(), null);
1946 JCBlock clinit = make.Block(STATIC, List.of(dummy));
1947 currentClassDef.defs = currentClassDef.defs.prepend(clinit);
1948 }
1949 }
1950 make_at(pos);
1951 return makeUnary(NOT, make.Ident(assertDisabledSym));
1952 }
1953
1954
1955 /* ************************************************************************
1956 * Building blocks for let expressions
1957 *************************************************************************/
1958
1959 interface TreeBuilder {
1960 JCExpression build(JCExpression arg);
1961 }
1962
1963 /** Construct an expression using the builder, with the given rval
1964 * expression as an argument to the builder. However, the rval
1965 * expression must be computed only once, even if used multiple
1966 * times in the result of the builder. We do that by
1967 * constructing a "let" expression that saves the rvalue into a
1968 * temporary variable and then uses the temporary variable in
1969 * place of the expression built by the builder. The complete
1970 * resulting expression is of the form
1971 * <pre>
1972 * (let <b>TYPE</b> <b>TEMP</b> = <b>RVAL</b>;
1973 * in (<b>BUILDER</b>(<b>TEMP</b>)))
1974 * </pre>
1975 * where <code><b>TEMP</b></code> is a newly declared variable
1976 * in the let expression.
1977 */
1978 JCExpression abstractRval(JCExpression rval, Type type, TreeBuilder builder) {
1979 rval = TreeInfo.skipParens(rval);
1980 switch (rval.getTag()) {
1981 case LITERAL:
1982 return builder.build(rval);
1983 case IDENT:
1984 JCIdent id = (JCIdent) rval;
1985 if ((id.sym.flags() & FINAL) != 0 && id.sym.owner.kind == MTH)
1986 return builder.build(rval);
1987 }
1988 Name name = TreeInfo.name(rval);
1989 if (name == names._super || name == names._this)
1990 return builder.build(rval);
1991 VarSymbol var =
1992 new VarSymbol(FINAL|SYNTHETIC,
1993 names.fromString(
1994 target.syntheticNameChar()
1995 + "" + rval.hashCode()),
1996 type,
1997 currentMethodSym);
1998 rval = convert(rval,type);
1999 JCVariableDecl def = make.VarDef(var, rval); // XXX cast
2000 JCExpression built = builder.build(make.Ident(var));
2001 JCExpression res = make.LetExpr(def, built);
2002 res.type = built.type;
2003 return res;
2004 }
2005
2006 // same as above, with the type of the temporary variable computed
2007 JCExpression abstractRval(JCExpression rval, TreeBuilder builder) {
2008 return abstractRval(rval, rval.type, builder);
2009 }
2010
2011 // same as above, but for an expression that may be used as either
2012 // an rvalue or an lvalue. This requires special handling for
2013 // Select expressions, where we place the left-hand-side of the
2014 // select in a temporary, and for Indexed expressions, where we
2015 // place both the indexed expression and the index value in temps.
2016 JCExpression abstractLval(JCExpression lval, final TreeBuilder builder) {
2017 lval = TreeInfo.skipParens(lval);
2018 switch (lval.getTag()) {
2019 case IDENT:
2020 return builder.build(lval);
2021 case SELECT: {
2022 final JCFieldAccess s = (JCFieldAccess)lval;
2023 Symbol lid = TreeInfo.symbol(s.selected);
2024 if (lid != null && lid.kind == TYP) return builder.build(lval);
2025 return abstractRval(s.selected, selected -> builder.build(make.Select(selected, s.sym)));
2026 }
2027 case INDEXED: {
2028 final JCArrayAccess i = (JCArrayAccess)lval;
2029 return abstractRval(i.indexed, indexed -> abstractRval(i.index, syms.intType, index -> {
2030 JCExpression newLval = make.Indexed(indexed, index);
2031 newLval.setType(i.type);
2032 return builder.build(newLval);
2033 }));
2034 }
2035 case TYPECAST: {
2036 return abstractLval(((JCTypeCast)lval).expr, builder);
2037 }
2038 }
2039 throw new AssertionError(lval);
2040 }
2041
2042 // evaluate and discard the first expression, then evaluate the second.
2043 JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) {
2044 JCExpression res = make.LetExpr(List.of(make.Exec(expr1)), expr2);
2045 res.type = expr2.type;
2046 return res;
2047 }
2048
2049 /* ************************************************************************
2050 * Translation methods
2051 *************************************************************************/
2052
2053 /** Visitor argument: enclosing operator node.
2054 */
2055 private JCExpression enclOp;
2056
2057 /** Visitor method: Translate a single node.
2058 * Attach the source position from the old tree to its replacement tree.
2059 */
2060 @Override
2061 public <T extends JCTree> T translate(T tree) {
2062 if (tree == null) {
2063 return null;
2064 } else {
2065 make_at(tree.pos());
2066 T result = super.translate(tree);
2067 if (result != null && result != tree) {
2068 result.endpos = tree.endpos;
2069 }
2070 return result;
2071 }
2072 }
2073
2074 /** Visitor method: Translate a single node, boxing or unboxing if needed.
2075 */
2076 public <T extends JCExpression> T translate(T tree, Type type) {
2077 return (tree == null) ? null : boxIfNeeded(translate(tree), type);
2078 }
2079
2080 /** Visitor method: Translate tree.
2081 */
2082 public <T extends JCTree> T translate(T tree, JCExpression enclOp) {
2083 JCExpression prevEnclOp = this.enclOp;
2084 this.enclOp = enclOp;
2085 T res = translate(tree);
2086 this.enclOp = prevEnclOp;
2087 return res;
2088 }
2089
2090 /** Visitor method: Translate list of trees.
2091 */
2092 public <T extends JCExpression> List<T> translate(List<T> trees, Type type) {
2093 if (trees == null) return null;
2094 for (List<T> l = trees; l.nonEmpty(); l = l.tail)
2095 l.head = translate(l.head, type);
2096 return trees;
2097 }
2098
2099 public void visitPackageDef(JCPackageDecl tree) {
2100 if (!needPackageInfoClass(tree))
2101 return;
2102
2103 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2104 // package-info is marked SYNTHETIC in JDK 1.6 and later releases
2105 flags = flags | Flags.SYNTHETIC;
2106 ClassSymbol c = tree.packge.package_info;
2107 c.setAttributes(tree.packge);
2108 c.flags_field |= flags;
2109 ClassType ctype = (ClassType) c.type;
2110 ctype.supertype_field = syms.objectType;
2111 ctype.interfaces_field = List.nil();
2112 createInfoClass(tree.annotations, c);
2113 }
2114 // where
2115 private boolean needPackageInfoClass(JCPackageDecl pd) {
2116 switch (pkginfoOpt) {
2117 case ALWAYS:
2118 return true;
2119 case LEGACY:
2120 return pd.getAnnotations().nonEmpty();
2121 case NONEMPTY:
2122 for (Attribute.Compound a :
2123 pd.packge.getDeclarationAttributes()) {
2124 Attribute.RetentionPolicy p = types.getRetention(a);
2125 if (p != Attribute.RetentionPolicy.SOURCE)
2126 return true;
2127 }
2128 return false;
2129 }
2130 throw new AssertionError();
2131 }
2132
2133 public void visitModuleDef(JCModuleDecl tree) {
2134 ModuleSymbol msym = tree.sym;
2135 ClassSymbol c = msym.module_info;
2136 c.setAttributes(msym);
2137 c.flags_field |= Flags.MODULE;
2138 createInfoClass(List.nil(), tree.sym.module_info);
2139 }
2140
2141 private void createInfoClass(List<JCAnnotation> annots, ClassSymbol c) {
2142 long flags = Flags.ABSTRACT | Flags.INTERFACE;
2143 JCClassDecl infoClass =
2144 make.ClassDef(make.Modifiers(flags, annots),
2145 c.name, List.nil(),
2146 null, List.nil(), List.nil());
2147 infoClass.sym = c;
2148 translated.append(infoClass);
2149 }
2150
2151 public void visitClassDef(JCClassDecl tree) {
2152 Env<AttrContext> prevEnv = attrEnv;
2153 ClassSymbol currentClassPrev = currentClass;
2154 MethodSymbol currentMethodSymPrev = currentMethodSym;
2155
2156 currentClass = tree.sym;
2157 currentMethodSym = null;
2158 attrEnv = typeEnvs.remove(currentClass);
2159 if (attrEnv == null)
2160 attrEnv = prevEnv;
2161
2162 classdefs.put(currentClass, tree);
2163
2164 Map<Symbol, Symbol> prevProxies = proxies;
2165 proxies = new HashMap<>(proxies);
2166 List<VarSymbol> prevOuterThisStack = outerThisStack;
2167
2168 // If this is an enum definition
2169 if ((tree.mods.flags & ENUM) != 0 &&
2170 (types.supertype(currentClass.type).tsym.flags() & ENUM) == 0)
2171 visitEnumDef(tree);
2172
2173 if ((tree.mods.flags & RECORD) != 0) {
2174 visitRecordDef(tree);
2175 }
2176
2177 // If this is a nested class, define a this$n field for
2178 // it and add to proxies.
2179 JCVariableDecl otdef = null;
2180 if (currentClass.hasOuterInstance())
2181 otdef = outerThisDef(tree.pos, currentClass);
2182
2183 // If this is a local class, define proxies for all its free variables.
2184 List<JCVariableDecl> fvdefs = freevarDefs(
2185 tree.pos, freevars(currentClass), currentClass);
2186
2187 // Recursively translate superclass, interfaces.
2188 tree.extending = translate(tree.extending);
2189 tree.implementing = translate(tree.implementing);
2190
2191 if (currentClass.isDirectlyOrIndirectlyLocal()) {
2192 ClassSymbol encl = currentClass.owner.enclClass();
2193 if (encl.trans_local == null) {
2194 encl.trans_local = List.nil();
2195 }
2196 encl.trans_local = encl.trans_local.prepend(currentClass);
2197 }
2198
2199 // Recursively translate members, taking into account that new members
2200 // might be created during the translation and prepended to the member
2201 // list `tree.defs'.
2202 List<JCTree> seen = List.nil();
2203 while (tree.defs != seen) {
2204 List<JCTree> unseen = tree.defs;
2205 for (List<JCTree> l = unseen; l.nonEmpty() && l != seen; l = l.tail) {
2206 JCTree outermostMemberDefPrev = outermostMemberDef;
2207 if (outermostMemberDefPrev == null) outermostMemberDef = l.head;
2208 l.head = translate(l.head);
2209 outermostMemberDef = outermostMemberDefPrev;
2210 }
2211 seen = unseen;
2212 }
2213
2214 // Convert a protected modifier to public, mask static modifier.
2215 if ((tree.mods.flags & PROTECTED) != 0) tree.mods.flags |= PUBLIC;
2216 tree.mods.flags &= ClassFlags;
2217
2218 // Convert name to flat representation, replacing '.' by '$'.
2219 tree.name = Convert.shortName(currentClass.flatName());
2220
2221 // Add free variables proxy definitions to class.
2222
2223 for (List<JCVariableDecl> l = fvdefs; l.nonEmpty(); l = l.tail) {
2224 tree.defs = tree.defs.prepend(l.head);
2225 enterSynthetic(tree.pos(), l.head.sym, currentClass.members());
2226 }
2227 // If this$n was accessed, add the field definition and prepend
2228 // initializer code to any super() invocation to initialize it
2229 // otherwise prepend enclosing instance null check code if required
2230 emitOuter:
2231 if (currentClass.hasOuterInstance()) {
2232 boolean storesThis = shouldEmitOuterThis(currentClass);
2233 if (storesThis) {
2234 tree.defs = tree.defs.prepend(otdef);
2235 enterSynthetic(tree.pos(), otdef.sym, currentClass.members());
2236 } else if (!nullCheckOuterThis) {
2237 break emitOuter;
2238 }
2239
2240 for (JCTree def : tree.defs) {
2241 if (TreeInfo.isConstructor(def)) {
2242 JCMethodDecl mdef = (JCMethodDecl)def;
2243 if (TreeInfo.hasConstructorCall(mdef, names._super)) {
2244 List<JCStatement> initializer = List.of(initOuterThis(mdef.body.pos, mdef.params.head.sym, storesThis)) ;
2245 TreeInfo.mapSuperCalls(mdef.body, supercall -> make.Block(0, initializer.append(supercall)));
2246 }
2247 }
2248 }
2249 }
2250
2251 proxies = prevProxies;
2252 outerThisStack = prevOuterThisStack;
2253
2254 // Append translated tree to `translated' queue.
2255 translated.append(tree);
2256
2257 attrEnv = prevEnv;
2258 currentClass = currentClassPrev;
2259 currentMethodSym = currentMethodSymPrev;
2260
2261 // Return empty block {} as a placeholder for an inner class.
2262 result = make_at(tree.pos()).Block(SYNTHETIC, List.nil());
2263 }
2264
2265 private boolean shouldEmitOuterThis(ClassSymbol sym) {
2266 if (!optimizeOuterThis) {
2267 // Optimization is disabled
2268 return true;
2269 }
2270 if ((outerThisStack.head.flags_field & NOOUTERTHIS) == 0) {
2271 // Enclosing instance field is used
2272 return true;
2273 }
2274 if (rs.isSerializable(sym.type)) {
2275 // Class is serializable
2276 return true;
2277 }
2278 if (sym.isValueClass()) {
2279 // Omitting enclosing instance field in value classes changes ==
2280 return true;
2281 }
2282 return false;
2283 }
2284
2285 List<JCTree> generateMandatedAccessors(JCClassDecl tree) {
2286 List<JCVariableDecl> fields = TreeInfo.recordFields(tree);
2287 return tree.sym.getRecordComponents().stream()
2288 .filter(rc -> (rc.accessor.flags() & Flags.GENERATED_MEMBER) != 0)
2289 .map(rc -> {
2290 // we need to return the field not the record component
2291 JCVariableDecl field = fields.stream().filter(f -> f.name == rc.name).findAny().get();
2292 make_at(tree.pos());
2293 return make.MethodDef(rc.accessor, make.Block(0,
2294 List.of(make.Return(make.Ident(field)))));
2295 }).collect(List.collector());
2296 }
2297
2298 /** Translate an enum class. */
2299 private void visitEnumDef(JCClassDecl tree) {
2300 make_at(tree.pos());
2301
2302 // add the supertype, if needed
2303 if (tree.extending == null)
2304 tree.extending = make.Type(types.supertype(tree.type));
2305
2306 // classOfType adds a cache field to tree.defs
2307 JCExpression e_class = classOfType(tree.sym.type, tree.pos()).
2308 setType(types.erasure(syms.classType));
2309
2310 // process each enumeration constant, adding implicit constructor parameters
2311 int nextOrdinal = 0;
2312 ListBuffer<JCExpression> values = new ListBuffer<>();
2313 ListBuffer<JCTree> enumDefs = new ListBuffer<>();
2314 ListBuffer<JCTree> otherDefs = new ListBuffer<>();
2315 for (List<JCTree> defs = tree.defs;
2316 defs.nonEmpty();
2317 defs=defs.tail) {
2318 if (defs.head.hasTag(VARDEF) && (((JCVariableDecl) defs.head).mods.flags & ENUM) != 0) {
2319 JCVariableDecl var = (JCVariableDecl)defs.head;
2320 visitEnumConstantDef(var, nextOrdinal++);
2321 values.append(make.QualIdent(var.sym));
2322 enumDefs.append(var);
2323 } else {
2324 otherDefs.append(defs.head);
2325 }
2326 }
2327
2328 // synthetic private static T[] $values() { return new T[] { a, b, c }; }
2329 // synthetic private static final T[] $VALUES = $values();
2330 Name valuesName = syntheticName(tree, "VALUES");
2331 Type arrayType = new ArrayType(types.erasure(tree.type), syms.arrayClass);
2332 VarSymbol valuesVar = new VarSymbol(PRIVATE|FINAL|STATIC|SYNTHETIC,
2333 valuesName,
2334 arrayType,
2335 tree.type.tsym);
2336 JCNewArray newArray = make.NewArray(make.Type(types.erasure(tree.type)),
2337 List.nil(),
2338 values.toList());
2339 newArray.type = arrayType;
2340
2341 MethodSymbol valuesMethod = new MethodSymbol(PRIVATE|STATIC|SYNTHETIC,
2342 syntheticName(tree, "values"),
2343 new MethodType(List.nil(), arrayType, List.nil(), tree.type.tsym),
2344 tree.type.tsym);
2345 enumDefs.append(make.MethodDef(valuesMethod, make.Block(0, List.of(make.Return(newArray)))));
2346 tree.sym.members().enter(valuesMethod);
2347
2348 enumDefs.append(make.VarDef(valuesVar, make.App(make.QualIdent(valuesMethod))));
2349 tree.sym.members().enter(valuesVar);
2350
2351 MethodSymbol valuesSym = lookupMethod(tree.pos(), names.values,
2352 tree.type, List.nil());
2353 List<JCStatement> valuesBody;
2354 if (useClone()) {
2355 // return (T[]) $VALUES.clone();
2356 JCTypeCast valuesResult =
2357 make.TypeCast(valuesSym.type.getReturnType(),
2358 make.App(make.Select(make.Ident(valuesVar),
2359 syms.arrayCloneMethod)));
2360 valuesBody = List.of(make.Return(valuesResult));
2361 } else {
2362 // template: T[] $result = new T[$values.length];
2363 Name resultName = syntheticName(tree, "result");
2364 VarSymbol resultVar = new VarSymbol(FINAL|SYNTHETIC,
2365 resultName,
2366 arrayType,
2367 valuesSym);
2368 JCNewArray resultArray = make.NewArray(make.Type(types.erasure(tree.type)),
2369 List.of(make.Select(make.Ident(valuesVar), syms.lengthVar)),
2370 null);
2371 resultArray.type = arrayType;
2372 JCVariableDecl decl = make.VarDef(resultVar, resultArray);
2373
2374 // template: System.arraycopy($VALUES, 0, $result, 0, $VALUES.length);
2375 if (systemArraycopyMethod == null) {
2376 systemArraycopyMethod =
2377 new MethodSymbol(PUBLIC | STATIC,
2378 names.fromString("arraycopy"),
2379 new MethodType(List.of(syms.objectType,
2380 syms.intType,
2381 syms.objectType,
2382 syms.intType,
2383 syms.intType),
2384 syms.voidType,
2385 List.nil(),
2386 syms.methodClass),
2387 syms.systemType.tsym);
2388 }
2389 JCStatement copy =
2390 make.Exec(make.App(make.Select(make.Ident(syms.systemType.tsym),
2391 systemArraycopyMethod),
2392 List.of(make.Ident(valuesVar), make.Literal(0),
2393 make.Ident(resultVar), make.Literal(0),
2394 make.Select(make.Ident(valuesVar), syms.lengthVar))));
2395
2396 // template: return $result;
2397 JCStatement ret = make.Return(make.Ident(resultVar));
2398 valuesBody = List.of(decl, copy, ret);
2399 }
2400
2401 JCMethodDecl valuesDef =
2402 make.MethodDef(valuesSym, make.Block(0, valuesBody));
2403
2404 enumDefs.append(valuesDef);
2405
2406 if (debugLower)
2407 System.err.println(tree.sym + ".valuesDef = " + valuesDef);
2408
2409 /** The template for the following code is:
2410 *
2411 * public static E valueOf(String name) {
2412 * return (E)Enum.valueOf(E.class, name);
2413 * }
2414 *
2415 * where E is tree.sym
2416 */
2417 MethodSymbol valueOfSym = lookupMethod(tree.pos(),
2418 names.valueOf,
2419 tree.sym.type,
2420 List.of(syms.stringType));
2421 Assert.check((valueOfSym.flags() & STATIC) != 0);
2422 VarSymbol nameArgSym = valueOfSym.params.head;
2423 JCIdent nameVal = make.Ident(nameArgSym);
2424 JCStatement enum_ValueOf =
2425 make.Return(make.TypeCast(tree.sym.type,
2426 makeCall(make.Ident(syms.enumSym),
2427 names.valueOf,
2428 List.of(e_class, nameVal))));
2429 JCMethodDecl valueOf = make.MethodDef(valueOfSym,
2430 make.Block(0, List.of(enum_ValueOf)));
2431 nameVal.sym = valueOf.params.head.sym;
2432 if (debugLower)
2433 System.err.println(tree.sym + ".valueOf = " + valueOf);
2434 enumDefs.append(valueOf);
2435
2436 enumDefs.appendList(otherDefs.toList());
2437 tree.defs = enumDefs.toList();
2438 }
2439 // where
2440 private MethodSymbol systemArraycopyMethod;
2441 private boolean useClone() {
2442 try {
2443 return syms.objectType.tsym.members().findFirst(names.clone) != null;
2444 }
2445 catch (CompletionFailure e) {
2446 return false;
2447 }
2448 }
2449
2450 private Name syntheticName(JCClassDecl tree, String baseName) {
2451 Name valuesName = names.fromString(target.syntheticNameChar() + baseName);
2452 while (tree.sym.members().findFirst(valuesName) != null) // avoid name clash
2453 valuesName = names.fromString(valuesName + "" + target.syntheticNameChar());
2454 return valuesName;
2455 }
2456
2457 /** Translate an enumeration constant and its initializer. */
2458 private void visitEnumConstantDef(JCVariableDecl var, int ordinal) {
2459 JCNewClass varDef = (JCNewClass)var.init;
2460 varDef.args = varDef.args.
2461 prepend(makeLit(syms.intType, ordinal)).
2462 prepend(makeLit(syms.stringType, var.name.toString()));
2463 }
2464
2465 private List<VarSymbol> recordVars(Type t) {
2466 List<VarSymbol> vars = List.nil();
2467 while (!t.hasTag(NONE)) {
2468 if (t.hasTag(CLASS)) {
2469 for (Symbol s : t.tsym.members().getSymbols(s -> s.kind == VAR && (s.flags() & RECORD) != 0)) {
2470 vars = vars.prepend((VarSymbol)s);
2471 }
2472 }
2473 t = types.supertype(t);
2474 }
2475 return vars;
2476 }
2477
2478 /** Translate a record. */
2479 private void visitRecordDef(JCClassDecl tree) {
2480 make_at(tree.pos());
2481 List<VarSymbol> vars = recordVars(tree.type);
2482 MethodHandleSymbol[] getterMethHandles = new MethodHandleSymbol[vars.size()];
2483 int index = 0;
2484 for (VarSymbol var : vars) {
2485 if (var.owner != tree.sym) {
2486 var = new VarSymbol(var.flags_field, var.name, var.type, tree.sym);
2487 }
2488 getterMethHandles[index] = var.asMethodHandle(true);
2489 index++;
2490 }
2491
2492 tree.defs = tree.defs.appendList(generateMandatedAccessors(tree));
2493 tree.defs = tree.defs.appendList(List.of(
2494 generateRecordMethod(tree, names.toString, vars, getterMethHandles),
2495 generateRecordMethod(tree, names.hashCode, vars, getterMethHandles),
2496 generateRecordMethod(tree, names.equals, vars, getterMethHandles)
2497 ));
2498 }
2499
2500 JCTree generateRecordMethod(JCClassDecl tree, Name name, List<VarSymbol> vars, MethodHandleSymbol[] getterMethHandles) {
2501 make_at(tree.pos());
2502 boolean isEquals = name == names.equals;
2503 MethodSymbol msym = lookupMethod(tree.pos(),
2504 name,
2505 tree.sym.type,
2506 isEquals ? List.of(syms.objectType) : List.nil());
2507 // compiler generated methods have the record flag set, user defined ones dont
2508 if ((msym.flags() & RECORD) != 0) {
2509 /* class java.lang.runtime.ObjectMethods provides a common bootstrap that provides a customized implementation
2510 * for methods: toString, hashCode and equals. Here we just need to generate and indy call to:
2511 * java.lang.runtime.ObjectMethods::bootstrap and provide: the record class, the record component names and
2512 * the accessors.
2513 */
2514 Name bootstrapName = names.bootstrap;
2515 LoadableConstant[] staticArgsValues = new LoadableConstant[2 + getterMethHandles.length];
2516 staticArgsValues[0] = (ClassType)tree.sym.type;
2517 String concatNames = vars.stream()
2518 .map(v -> v.name)
2519 .collect(Collectors.joining(";", "", ""));
2520 staticArgsValues[1] = LoadableConstant.String(concatNames);
2521 int index = 2;
2522 for (MethodHandleSymbol mho : getterMethHandles) {
2523 staticArgsValues[index] = mho;
2524 index++;
2525 }
2526
2527 List<Type> staticArgTypes = List.of(syms.classType,
2528 syms.stringType,
2529 new ArrayType(syms.methodHandleType, syms.arrayClass));
2530
2531 JCFieldAccess qualifier = makeIndyQualifier(syms.objectMethodsType, tree, msym,
2532 List.of(syms.methodHandleLookupType,
2533 syms.stringType,
2534 syms.typeDescriptorType).appendList(staticArgTypes),
2535 staticArgsValues, bootstrapName, name, false);
2536
2537 VarSymbol _this = new VarSymbol(SYNTHETIC, names._this, tree.sym.type, tree.sym);
2538
2539 JCMethodInvocation proxyCall;
2540 if (!isEquals) {
2541 proxyCall = make.Apply(List.nil(), qualifier, List.of(make.Ident(_this)));
2542 } else {
2543 VarSymbol o = msym.params.head;
2544 o.adr = 0;
2545 proxyCall = make.Apply(List.nil(), qualifier, List.of(make.Ident(_this), make.Ident(o)));
2546 }
2547 proxyCall.type = qualifier.type;
2548 return make.MethodDef(msym, make.Block(0, List.of(make.Return(proxyCall))));
2549 } else {
2550 return make.Block(SYNTHETIC, List.nil());
2551 }
2552 }
2553
2554 private String argsTypeSig(List<Type> typeList) {
2555 LowerSignatureGenerator sg = new LowerSignatureGenerator();
2556 sg.assembleSig(typeList);
2557 return sg.toString();
2558 }
2559
2560 /**
2561 * Signature Generation
2562 */
2563 private class LowerSignatureGenerator extends Types.SignatureGenerator {
2564
2565 /**
2566 * An output buffer for type signatures.
2567 */
2568 StringBuilder sb = new StringBuilder();
2569
2570 LowerSignatureGenerator() {
2571 types.super();
2572 }
2573
2574 @Override
2575 protected void append(char ch) {
2576 sb.append(ch);
2577 }
2578
2579 @Override
2580 protected void append(byte[] ba) {
2581 sb.append(new String(ba));
2582 }
2583
2584 @Override
2585 protected void append(Name name) {
2586 sb.append(name.toString());
2587 }
2588
2589 @Override
2590 public String toString() {
2591 return sb.toString();
2592 }
2593 }
2594
2595 /**
2596 * Creates an indy qualifier, helpful to be part of an indy invocation
2597 * @param site the site
2598 * @param tree a class declaration tree
2599 * @param msym the method symbol
2600 * @param staticArgTypes the static argument types
2601 * @param staticArgValues the static argument values
2602 * @param bootstrapName the bootstrap name to look for
2603 * @param argName normally bootstraps receives a method name as second argument, if you want that name
2604 * to be different to that of the bootstrap name pass a different name here
2605 * @param isStatic is it static or not
2606 * @return a field access tree
2607 */
2608 JCFieldAccess makeIndyQualifier(
2609 Type site,
2610 JCClassDecl tree,
2611 MethodSymbol msym,
2612 List<Type> staticArgTypes,
2613 LoadableConstant[] staticArgValues,
2614 Name bootstrapName,
2615 Name argName,
2616 boolean isStatic) {
2617 MethodSymbol bsm = rs.resolveInternalMethod(tree.pos(), attrEnv, site,
2618 bootstrapName, staticArgTypes, List.nil());
2619
2620 MethodType indyType = msym.type.asMethodType();
2621 indyType = new MethodType(
2622 isStatic ? List.nil() : indyType.argtypes.prepend(tree.sym.type),
2623 indyType.restype,
2624 indyType.thrown,
2625 syms.methodClass
2626 );
2627 DynamicMethodSymbol dynSym = new DynamicMethodSymbol(argName,
2628 syms.noSymbol,
2629 bsm.asHandle(),
2630 indyType,
2631 staticArgValues);
2632 JCFieldAccess qualifier = make.Select(make.QualIdent(site.tsym), argName);
2633 qualifier.sym = dynSym;
2634 qualifier.type = msym.type.asMethodType().restype;
2635 return qualifier;
2636 }
2637
2638 public void visitMethodDef(JCMethodDecl tree) {
2639 if (tree.name == names.init && (currentClass.flags_field&ENUM) != 0) {
2640 // Add "String $enum$name, int $enum$ordinal" to the beginning of the
2641 // argument list for each constructor of an enum.
2642 JCVariableDecl nameParam = make_at(tree.pos()).
2643 Param(names.fromString(target.syntheticNameChar() +
2644 "enum" + target.syntheticNameChar() + "name"),
2645 syms.stringType, tree.sym);
2646 nameParam.mods.flags |= SYNTHETIC; nameParam.sym.flags_field |= SYNTHETIC;
2647 JCVariableDecl ordParam = make.
2648 Param(names.fromString(target.syntheticNameChar() +
2649 "enum" + target.syntheticNameChar() +
2650 "ordinal"),
2651 syms.intType, tree.sym);
2652 ordParam.mods.flags |= SYNTHETIC; ordParam.sym.flags_field |= SYNTHETIC;
2653
2654 MethodSymbol m = tree.sym;
2655 tree.params = tree.params.prepend(ordParam).prepend(nameParam);
2656
2657 m.extraParams = m.extraParams.prepend(ordParam.sym);
2658 m.extraParams = m.extraParams.prepend(nameParam.sym);
2659 Type olderasure = m.erasure(types);
2660 m.erasure_field = new MethodType(
2661 olderasure.getParameterTypes().prepend(syms.intType).prepend(syms.stringType),
2662 olderasure.getReturnType(),
2663 olderasure.getThrownTypes(),
2664 syms.methodClass);
2665 }
2666
2667 Type prevRestype = currentRestype;
2668 JCMethodDecl prevMethodDef = currentMethodDef;
2669 MethodSymbol prevMethodSym = currentMethodSym;
2670 int prevVariableIndex = variableIndex;
2671 try {
2672 currentRestype = types.erasure(tree.type.getReturnType());
2673 currentMethodDef = tree;
2674 currentMethodSym = tree.sym;
2675 variableIndex = 0;
2676 visitMethodDefInternal(tree);
2677 } finally {
2678 currentRestype = prevRestype;
2679 currentMethodDef = prevMethodDef;
2680 currentMethodSym = prevMethodSym;
2681 variableIndex = prevVariableIndex;
2682 }
2683 }
2684
2685 private void visitMethodDefInternal(JCMethodDecl tree) {
2686 if (tree.name == names.init &&
2687 !currentClass.isStatic() &&
2688 (currentClass.isInner() || currentClass.isDirectlyOrIndirectlyLocal())) {
2689 // We are seeing a constructor of an inner class.
2690 MethodSymbol m = tree.sym;
2691
2692 // Push a new proxy scope for constructor parameters.
2693 // and create definitions for any this$n and proxy parameters.
2694 Map<Symbol, Symbol> prevProxies = proxies;
2695 proxies = new HashMap<>(proxies);
2696 List<VarSymbol> prevOuterThisStack = outerThisStack;
2697 List<VarSymbol> fvs = freevars(currentClass);
2698 JCVariableDecl otdef = null;
2699 if (currentClass.hasOuterInstance())
2700 otdef = outerThisDef(tree.pos, m);
2701 List<JCVariableDecl> fvdefs = freevarDefs(tree.pos, fvs, m, PARAMETER);
2702
2703 // Recursively translate result type, parameters and thrown list.
2704 tree.restype = translate(tree.restype);
2705 tree.params = translateVarDefs(tree.params);
2706 tree.thrown = translate(tree.thrown);
2707
2708 // when compiling stubs, don't process body
2709 if (tree.body == null) {
2710 result = tree;
2711 return;
2712 }
2713
2714 // Add this$n (if needed) in front of and free variables behind
2715 // constructor parameter list.
2716 tree.params = tree.params.appendList(fvdefs);
2717 if (currentClass.hasOuterInstance()) {
2718 tree.params = tree.params.prepend(otdef);
2719 }
2720
2721 // Determine whether this constructor has a super() invocation
2722 boolean invokesSuper = TreeInfo.hasConstructorCall(tree, names._super);
2723
2724 // Create initializers for this$n and proxies
2725 ListBuffer<JCStatement> added = new ListBuffer<>();
2726 if (fvs.nonEmpty()) {
2727 List<Type> addedargtypes = List.nil();
2728 for (List<VarSymbol> l = fvs; l.nonEmpty(); l = l.tail) {
2729 m.capturedLocals =
2730 m.capturedLocals.prepend((VarSymbol)
2731 (proxies.get(l.head)));
2732 if (invokesSuper) {
2733 added = added.prepend(
2734 initField(tree.body.pos, proxies.get(l.head), prevProxies.get(l.head)));
2735 }
2736 addedargtypes = addedargtypes.prepend(l.head.erasure(types));
2737 }
2738 Type olderasure = m.erasure(types);
2739 m.erasure_field = new MethodType(
2740 olderasure.getParameterTypes().appendList(addedargtypes),
2741 olderasure.getReturnType(),
2742 olderasure.getThrownTypes(),
2743 syms.methodClass);
2744 }
2745
2746 // Recursively translate existing local statements
2747 tree.body.stats = translate(tree.body.stats);
2748
2749 // Prepend initializers in front of super() call
2750 if (added.nonEmpty()) {
2751 List<JCStatement> initializers = added.toList();
2752 TreeInfo.mapSuperCalls(tree.body, supercall -> make.Block(0, initializers.append(supercall)));
2753 }
2754
2755 // pop local variables from proxy stack
2756 proxies = prevProxies;
2757
2758 outerThisStack = prevOuterThisStack;
2759 } else {
2760 super.visitMethodDef(tree);
2761 }
2762 if (tree.name == names.init && ((tree.sym.flags_field & Flags.COMPACT_RECORD_CONSTRUCTOR) != 0 ||
2763 (tree.sym.flags_field & (GENERATEDCONSTR | RECORD)) == (GENERATEDCONSTR | RECORD))) {
2764 // lets find out if there is any field waiting to be initialized
2765 ListBuffer<VarSymbol> fields = new ListBuffer<>();
2766 for (Symbol sym : currentClass.getEnclosedElements()) {
2767 if (sym.kind == Kinds.Kind.VAR && ((sym.flags() & RECORD) != 0))
2768 fields.append((VarSymbol) sym);
2769 }
2770 ListBuffer<JCStatement> initializers = new ListBuffer<>();
2771 for (VarSymbol field: fields) {
2772 if ((field.flags_field & Flags.UNINITIALIZED_FIELD) != 0) {
2773 VarSymbol param = tree.params.stream().filter(p -> p.name == field.name).findFirst().get().sym;
2774 make.at(tree.pos);
2775 initializers.add(make.Exec(
2776 make.Assign(
2777 make.Select(make.This(field.owner.erasure(types)), field),
2778 make.Ident(param)).setType(field.erasure(types))));
2779 field.flags_field &= ~Flags.UNINITIALIZED_FIELD;
2780 }
2781 }
2782 if (initializers.nonEmpty()) {
2783 if (allowValueClasses && (tree.sym.owner.isValueClass() || ((ClassSymbol)tree.sym.owner).isRecord())) {
2784 TreeInfo.mapSuperCalls(tree.body, supercall -> make.Block(0, initializers.toList().append(supercall)));
2785 } else {
2786 tree.body.stats = tree.body.stats.appendList(initializers);
2787 }
2788 }
2789 }
2790 result = tree;
2791 }
2792
2793 public void visitTypeCast(JCTypeCast tree) {
2794 tree.clazz = translate(tree.clazz);
2795 if (tree.type.isPrimitive() != tree.expr.type.isPrimitive())
2796 tree.expr = translate(tree.expr, tree.type);
2797 else
2798 tree.expr = translate(tree.expr);
2799 result = tree;
2800 }
2801
2802 /**
2803 * All the exactness checks between primitive types that require a run-time
2804 * check are in {@code java.lang.runtime.ExactConversionsSupport}. Those methods
2805 * are in the form {@code ExactConversionsSupport.is<S>To<T>Exact} where both
2806 * {@code S} and {@code T} are primitive types and correspond to the runtime
2807 * action that will be executed to check whether a certain value (that is passed
2808 * as a parameter) can be converted to {@code T} without loss of information.
2809 *
2810 * Rewrite {@code instanceof if expr : Object} and Type is primitive type:
2811 *
2812 * {@snippet :
2813 * Object v = ...
2814 * if (v instanceof float)
2815 * =>
2816 * if (let tmp$123 = v; tmp$123 instanceof Float)
2817 * }
2818 *
2819 * Rewrite {@code instanceof if expr : wrapper reference type}
2820 *
2821 * {@snippet :
2822 * Integer v = ...
2823 * if (v instanceof float)
2824 * =>
2825 * if (let tmp$123 = v; tmp$123 != null && ExactConversionsSupport.intToFloatExact(tmp$123.intValue()))
2826 * }
2827 *
2828 * Rewrite {@code instanceof if expr : primitive}
2829 *
2830 * {@snippet :
2831 * int v = ...
2832 * if (v instanceof float)
2833 * =>
2834 * if (let tmp$123 = v; ExactConversionsSupport.intToFloatExact(tmp$123))
2835 * }
2836 *
2837 * More rewritings:
2838 * <ul>
2839 * <li>If the {@code instanceof} check is unconditionally exact rewrite to true.</li>
2840 * <li>If expression type is {@code Byte}, {@code Short}, {@code Integer}, ..., an
2841 * unboxing conversion followed by a widening primitive conversion.</li>
2842 * <li>If expression type is a supertype: {@code Number}, a narrowing reference
2843 * conversion followed by an unboxing conversion.</li>
2844 * </ul>
2845 */
2846 public void visitTypeTest(JCInstanceOf tree) {
2847 if (tree.expr.type.isPrimitive() || tree.pattern.type.isPrimitive()) {
2848 JCStatement prefixStatement;
2849 JCExpression exactnessCheck;
2850 JCExpression instanceOfExpr = translate(tree.expr);
2851
2852 if (types.isUnconditionallyExactTypeBased(tree.expr.type, tree.pattern.type)) {
2853 // instanceOfExpr; true
2854 prefixStatement = make.Exec(instanceOfExpr);
2855 exactnessCheck = make.Literal(BOOLEAN, 1).setType(syms.booleanType.constType(1));
2856 } else if (tree.expr.type.isPrimitive()) {
2857 // ExactConversionSupport.isXxxExact(instanceOfExpr)
2858 prefixStatement = null;
2859 exactnessCheck = getExactnessCheck(tree, instanceOfExpr);
2860 } else if (tree.expr.type.isReference()) {
2861 if (types.isUnconditionallyExactTypeBased(types.unboxedType(tree.expr.type), tree.pattern.type)) {
2862 // instanceOfExpr != null
2863 prefixStatement = null;
2864 exactnessCheck = makeBinary(NE, instanceOfExpr, makeNull());
2865 } else {
2866 // We read the result of instanceOfExpr, so create variable
2867 VarSymbol dollar_s = new VarSymbol(FINAL | SYNTHETIC,
2868 names.fromString("tmp" + variableIndex++ + this.target.syntheticNameChar()),
2869 types.erasure(tree.expr.type),
2870 currentMethodSym);
2871 prefixStatement = make.at(tree.pos())
2872 .VarDef(dollar_s, instanceOfExpr);
2873
2874 JCExpression nullCheck =
2875 makeBinary(NE,
2876 make.Ident(dollar_s),
2877 makeNull());
2878
2879 if (types.unboxedType(tree.expr.type).isPrimitive()) {
2880 exactnessCheck =
2881 makeBinary(AND,
2882 nullCheck,
2883 getExactnessCheck(tree, boxIfNeeded(make.Ident(dollar_s), types.unboxedType(tree.expr.type))));
2884 } else {
2885 exactnessCheck =
2886 makeBinary(AND,
2887 nullCheck,
2888 make.at(tree.pos())
2889 .TypeTest(make.Ident(dollar_s), make.Type(types.boxedClass(tree.pattern.type).type))
2890 .setType(syms.booleanType));
2891 }
2892 }
2893 } else {
2894 throw Assert.error("Non primitive or reference type: " + tree.expr.type);
2895 }
2896 result = (prefixStatement == null ? exactnessCheck : make.LetExpr(List.of(prefixStatement), exactnessCheck))
2897 .setType(syms.booleanType);
2898 } else {
2899 tree.expr = translate(tree.expr);
2900 tree.pattern = translate(tree.pattern);
2901 result = tree;
2902 }
2903 }
2904
2905 // TypePairs should be in sync with the corresponding record in SwitchBootstraps
2906 record TypePairs(TypeSymbol from, TypeSymbol to) {
2907 public static TypePairs of(Symtab syms, Type from, Type to) {
2908 if (from == syms.byteType || from == syms.shortType || from == syms.charType) {
2909 from = syms.intType;
2910 }
2911 return new TypePairs(from, to);
2912 }
2913
2914 public TypePairs(Type from, Type to) {
2915 this(from.tsym, to.tsym);
2916 }
2917
2918 public static HashMap<TypePairs, String> initialize(Symtab syms) {
2919 HashMap<TypePairs, String> typePairToName = new HashMap<>();
2920 typePairToName.put(new TypePairs(syms.byteType, syms.charType), "isIntToCharExact"); // redirected
2921 typePairToName.put(new TypePairs(syms.shortType, syms.byteType), "isIntToByteExact"); // redirected
2922 typePairToName.put(new TypePairs(syms.shortType, syms.charType), "isIntToCharExact"); // redirected
2923 typePairToName.put(new TypePairs(syms.charType, syms.byteType), "isIntToByteExact"); // redirected
2924 typePairToName.put(new TypePairs(syms.charType, syms.shortType), "isIntToShortExact"); // redirected
2925 typePairToName.put(new TypePairs(syms.intType, syms.byteType), "isIntToByteExact");
2926 typePairToName.put(new TypePairs(syms.intType, syms.shortType), "isIntToShortExact");
2927 typePairToName.put(new TypePairs(syms.intType, syms.charType), "isIntToCharExact");
2928 typePairToName.put(new TypePairs(syms.intType, syms.floatType), "isIntToFloatExact");
2929 typePairToName.put(new TypePairs(syms.longType, syms.byteType), "isLongToByteExact");
2930 typePairToName.put(new TypePairs(syms.longType, syms.shortType), "isLongToShortExact");
2931 typePairToName.put(new TypePairs(syms.longType, syms.charType), "isLongToCharExact");
2932 typePairToName.put(new TypePairs(syms.longType, syms.intType), "isLongToIntExact");
2933 typePairToName.put(new TypePairs(syms.longType, syms.floatType), "isLongToFloatExact");
2934 typePairToName.put(new TypePairs(syms.longType, syms.doubleType), "isLongToDoubleExact");
2935 typePairToName.put(new TypePairs(syms.floatType, syms.byteType), "isFloatToByteExact");
2936 typePairToName.put(new TypePairs(syms.floatType, syms.shortType), "isFloatToShortExact");
2937 typePairToName.put(new TypePairs(syms.floatType, syms.charType), "isFloatToCharExact");
2938 typePairToName.put(new TypePairs(syms.floatType, syms.intType), "isFloatToIntExact");
2939 typePairToName.put(new TypePairs(syms.floatType, syms.longType), "isFloatToLongExact");
2940 typePairToName.put(new TypePairs(syms.doubleType, syms.byteType), "isDoubleToByteExact");
2941 typePairToName.put(new TypePairs(syms.doubleType, syms.shortType), "isDoubleToShortExact");
2942 typePairToName.put(new TypePairs(syms.doubleType, syms.charType), "isDoubleToCharExact");
2943 typePairToName.put(new TypePairs(syms.doubleType, syms.intType), "isDoubleToIntExact");
2944 typePairToName.put(new TypePairs(syms.doubleType, syms.longType), "isDoubleToLongExact");
2945 typePairToName.put(new TypePairs(syms.doubleType, syms.floatType), "isDoubleToFloatExact");
2946 return typePairToName;
2947 }
2948 }
2949
2950 private JCExpression getExactnessCheck(JCInstanceOf tree, JCExpression argument) {
2951 TypePairs pair = TypePairs.of(syms, types.unboxedTypeOrType(tree.expr.type), tree.pattern.type);
2952
2953 Name exactnessFunction = names.fromString(typePairToName.get(pair));
2954
2955 // Resolve the exactness method
2956 Symbol ecsym = lookupMethod(tree.pos(),
2957 exactnessFunction,
2958 syms.exactConversionsSupportType,
2959 List.of(pair.from.type));
2960
2961 // Generate the method call ExactnessChecks.<exactness method>(<argument>);
2962 JCFieldAccess select = make.Select(
2963 make.QualIdent(syms.exactConversionsSupportType.tsym),
2964 exactnessFunction);
2965 select.sym = ecsym;
2966 select.setType(syms.booleanType);
2967
2968 JCExpression exactnessCheck = make.Apply(List.nil(),
2969 select,
2970 List.of(argument));
2971 exactnessCheck.setType(syms.booleanType);
2972 return exactnessCheck;
2973 }
2974
2975 public void visitNewClass(JCNewClass tree) {
2976 ClassSymbol c = (ClassSymbol)tree.constructor.owner;
2977
2978 // Box arguments, if necessary
2979 boolean isEnum = (tree.constructor.owner.flags() & ENUM) != 0;
2980 List<Type> argTypes = tree.constructor.type.getParameterTypes();
2981 if (isEnum) argTypes = argTypes.prepend(syms.intType).prepend(syms.stringType);
2982 tree.args = boxArgs(argTypes, tree.args, tree.varargsElement);
2983 tree.varargsElement = null;
2984
2985 // If created class is local, add free variables after
2986 // explicit constructor arguments.
2987 if (c.isDirectlyOrIndirectlyLocal() && !c.isStatic()) {
2988 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
2989 }
2990
2991 // If an access constructor is used, append null as a last argument.
2992 Symbol constructor = accessConstructor(tree.pos(), tree.constructor);
2993 if (constructor != tree.constructor) {
2994 tree.args = tree.args.append(makeNull());
2995 tree.constructor = constructor;
2996 }
2997
2998 // If created class has an outer instance, and new is qualified, pass
2999 // qualifier as first argument. If new is not qualified, pass the
3000 // correct outer instance as first argument.
3001 if (c.hasOuterInstance()) {
3002 JCExpression thisArg;
3003 if (tree.encl != null) {
3004 thisArg = attr.makeNullCheck(translate(tree.encl));
3005 thisArg.type = tree.encl.type;
3006 } else if (c.isDirectlyOrIndirectlyLocal()) {
3007 // local class
3008 thisArg = makeThis(tree.pos(), c.innermostAccessibleEnclosingClass());
3009 } else {
3010 // nested class
3011 thisArg = makeOwnerThis(tree.pos(), c, false);
3012 }
3013 tree.args = tree.args.prepend(thisArg);
3014 }
3015 tree.encl = null;
3016
3017 // If we have an anonymous class, create its flat version, rather
3018 // than the class or interface following new.
3019 if (tree.def != null) {
3020 translate(tree.def);
3021
3022 tree.clazz = access(make_at(tree.clazz.pos()).Ident(tree.def.sym));
3023 tree.def = null;
3024 } else {
3025 tree.clazz = access(c, tree.clazz, enclOp, false);
3026 }
3027 result = tree;
3028 }
3029
3030 // Simplify conditionals with known constant controlling expressions.
3031 // This allows us to avoid generating supporting declarations for
3032 // the dead code, which will not be eliminated during code generation.
3033 // Note that Flow.isFalse and Flow.isTrue only return true
3034 // for constant expressions in the sense of JLS 15.27, which
3035 // are guaranteed to have no side-effects. More aggressive
3036 // constant propagation would require that we take care to
3037 // preserve possible side-effects in the condition expression.
3038
3039 // One common case is equality expressions involving a constant and null.
3040 // Since null is not a constant expression (because null cannot be
3041 // represented in the constant pool), equality checks involving null are
3042 // not captured by Flow.isTrue/isFalse.
3043 // Equality checks involving a constant and null, e.g.
3044 // "" == null
3045 // are safe to simplify as no side-effects can occur.
3046
3047 private boolean isTrue(JCTree exp) {
3048 if (exp.type.isTrue())
3049 return true;
3050 Boolean b = expValue(exp);
3051 return b == null ? false : b;
3052 }
3053 private boolean isFalse(JCTree exp) {
3054 if (exp.type.isFalse())
3055 return true;
3056 Boolean b = expValue(exp);
3057 return b == null ? false : !b;
3058 }
3059 /* look for (in)equality relations involving null.
3060 * return true - if expression is always true
3061 * false - if expression is always false
3062 * null - if expression cannot be eliminated
3063 */
3064 private Boolean expValue(JCTree exp) {
3065 while (exp.hasTag(PARENS))
3066 exp = ((JCParens)exp).expr;
3067
3068 boolean eq;
3069 switch (exp.getTag()) {
3070 case EQ: eq = true; break;
3071 case NE: eq = false; break;
3072 default:
3073 return null;
3074 }
3075
3076 // we have a JCBinary(EQ|NE)
3077 // check if we have two literals (constants or null)
3078 JCBinary b = (JCBinary)exp;
3079 if (b.lhs.type.hasTag(BOT)) return expValueIsNull(eq, b.rhs);
3080 if (b.rhs.type.hasTag(BOT)) return expValueIsNull(eq, b.lhs);
3081 return null;
3082 }
3083 private Boolean expValueIsNull(boolean eq, JCTree t) {
3084 if (t.type.hasTag(BOT)) return Boolean.valueOf(eq);
3085 if (t.hasTag(LITERAL)) return Boolean.valueOf(!eq);
3086 return null;
3087 }
3088
3089 /** Visitor method for conditional expressions.
3090 */
3091 @Override
3092 public void visitConditional(JCConditional tree) {
3093 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
3094 if (isTrue(cond) && noClassDefIn(tree.falsepart)) {
3095 result = convert(translate(tree.truepart, tree.type), tree.type);
3096 addPrunedInfo(cond);
3097 } else if (isFalse(cond) && noClassDefIn(tree.truepart)) {
3098 result = convert(translate(tree.falsepart, tree.type), tree.type);
3099 addPrunedInfo(cond);
3100 } else {
3101 // Condition is not a compile-time constant.
3102 tree.truepart = translate(tree.truepart, tree.type);
3103 tree.falsepart = translate(tree.falsepart, tree.type);
3104 result = tree;
3105 }
3106 }
3107 //where
3108 private JCExpression convert(JCExpression tree, Type pt) {
3109 if (tree.type == pt) return tree;
3110 JCExpression result = make_at(tree.pos()).TypeCast(make.Type(pt), tree);
3111 result.type = (tree.type.constValue() != null) ? cfolder.coerce(tree.type, pt)
3112 : pt;
3113 return result;
3114 }
3115
3116 /** Visitor method for if statements.
3117 */
3118 public void visitIf(JCIf tree) {
3119 JCTree cond = tree.cond = translate(tree.cond, syms.booleanType);
3120 if (isTrue(cond) && noClassDefIn(tree.elsepart)) {
3121 result = translate(tree.thenpart);
3122 addPrunedInfo(cond);
3123 } else if (isFalse(cond) && noClassDefIn(tree.thenpart)) {
3124 if (tree.elsepart != null) {
3125 result = translate(tree.elsepart);
3126 } else {
3127 result = make.Skip();
3128 }
3129 addPrunedInfo(cond);
3130 } else {
3131 // Condition is not a compile-time constant.
3132 tree.thenpart = translate(tree.thenpart);
3133 tree.elsepart = translate(tree.elsepart);
3134 result = tree;
3135 }
3136 }
3137
3138 /** Visitor method for assert statements. Translate them away.
3139 */
3140 public void visitAssert(JCAssert tree) {
3141 tree.cond = translate(tree.cond, syms.booleanType);
3142 if (!tree.cond.type.isTrue()) {
3143 JCExpression cond = assertFlagTest(tree.pos());
3144 List<JCExpression> exnArgs = (tree.detail == null) ?
3145 List.nil() : List.of(translate(tree.detail));
3146 if (!tree.cond.type.isFalse()) {
3147 cond = makeBinary
3148 (AND,
3149 cond,
3150 makeUnary(NOT, tree.cond));
3151 }
3152 result =
3153 make.If(cond,
3154 make_at(tree).
3155 Throw(makeNewClass(syms.assertionErrorType, exnArgs)),
3156 null);
3157 } else {
3158 result = make.Skip();
3159 }
3160 }
3161
3162 public void visitApply(JCMethodInvocation tree) {
3163 Symbol meth = TreeInfo.symbol(tree.meth);
3164 List<Type> argtypes = meth.type.getParameterTypes();
3165 if (meth.name == names.init && meth.owner == syms.enumSym)
3166 argtypes = argtypes.tail.tail;
3167 tree.args = boxArgs(argtypes, tree.args, tree.varargsElement);
3168 tree.varargsElement = null;
3169 Name methName = TreeInfo.name(tree.meth);
3170 if (meth.name==names.init) {
3171 // We are seeing a this(...) or super(...) constructor call.
3172 // If an access constructor is used, append null as a last argument.
3173 Symbol constructor = accessConstructor(tree.pos(), meth);
3174 if (constructor != meth) {
3175 tree.args = tree.args.append(makeNull());
3176 TreeInfo.setSymbol(tree.meth, constructor);
3177 }
3178
3179 // If we are calling a constructor of a local class, add
3180 // free variables after explicit constructor arguments.
3181 ClassSymbol c = (ClassSymbol)constructor.owner;
3182 if (c.isDirectlyOrIndirectlyLocal() && !c.isStatic()) {
3183 tree.args = tree.args.appendList(loadFreevars(tree.pos(), freevars(c)));
3184 }
3185
3186 // If we are calling a constructor of an enum class, pass
3187 // along the name and ordinal arguments
3188 if ((c.flags_field&ENUM) != 0 || c.getQualifiedName() == names.java_lang_Enum) {
3189 List<JCVariableDecl> params = currentMethodDef.params;
3190 if (currentMethodSym.owner.hasOuterInstance())
3191 params = params.tail; // drop this$n
3192 tree.args = tree.args
3193 .prepend(make_at(tree.pos()).Ident(params.tail.head.sym)) // ordinal
3194 .prepend(make.Ident(params.head.sym)); // name
3195 }
3196
3197 // If we are calling a constructor of a class with an outer
3198 // instance, and the call
3199 // is qualified, pass qualifier as first argument in front of
3200 // the explicit constructor arguments. If the call
3201 // is not qualified, pass the correct outer instance as
3202 // first argument. If we are a static class, there is no
3203 // such outer instance, so generate an error.
3204 if (c.hasOuterInstance()) {
3205 JCExpression thisArg;
3206 if (tree.meth.hasTag(SELECT)) {
3207 thisArg = attr.
3208 makeNullCheck(translate(((JCFieldAccess) tree.meth).selected));
3209 tree.meth = make.Ident(constructor);
3210 ((JCIdent) tree.meth).name = methName;
3211 } else if (c.isDirectlyOrIndirectlyLocal() || methName == names._this){
3212 // local class or this() call
3213 thisArg = makeThis(tree.meth.pos(), c.innermostAccessibleEnclosingClass());
3214 } else if (currentClass.isStatic()) {
3215 // super() call from static nested class - invalid
3216 log.error(tree.pos(),
3217 Errors.NoEnclInstanceOfTypeInScope(c.type.getEnclosingType().tsym));
3218 thisArg = make.Literal(BOT, null).setType(syms.botType);
3219 } else {
3220 // super() call of nested class - never pick 'this'
3221 thisArg = makeOwnerThisN(tree.meth.pos(), c, false);
3222 }
3223 tree.args = tree.args.prepend(thisArg);
3224 }
3225 } else {
3226 // We are seeing a normal method invocation; translate this as usual.
3227 tree.meth = translate(tree.meth);
3228
3229 // If the translated method itself is an Apply tree, we are
3230 // seeing an access method invocation. In this case, append
3231 // the method arguments to the arguments of the access method.
3232 if (tree.meth.hasTag(APPLY)) {
3233 JCMethodInvocation app = (JCMethodInvocation)tree.meth;
3234 app.args = tree.args.prependList(app.args);
3235 result = app;
3236 return;
3237 }
3238 }
3239 if (tree.args.stream().anyMatch(c -> c == null)) {
3240 throw new AssertionError("Whooops before: " + tree);
3241 }
3242 result = tree;
3243 }
3244
3245 List<JCExpression> boxArgs(List<Type> parameters, List<JCExpression> _args, Type varargsElement) {
3246 List<JCExpression> args = _args;
3247 if (parameters.isEmpty()) return args;
3248 boolean anyChanges = false;
3249 ListBuffer<JCExpression> result = new ListBuffer<>();
3250 while (parameters.tail.nonEmpty()) {
3251 JCExpression arg = translate(args.head, parameters.head);
3252 anyChanges |= (arg != args.head);
3253 result.append(arg);
3254 args = args.tail;
3255 parameters = parameters.tail;
3256 }
3257 Type parameter = parameters.head;
3258 if (varargsElement != null) {
3259 anyChanges = true;
3260 ListBuffer<JCExpression> elems = new ListBuffer<>();
3261 while (args.nonEmpty()) {
3262 JCExpression arg = translate(args.head, varargsElement);
3263 elems.append(arg);
3264 args = args.tail;
3265 }
3266 JCNewArray boxedArgs = make.NewArray(make.Type(varargsElement),
3267 List.nil(),
3268 elems.toList());
3269 boxedArgs.type = new ArrayType(varargsElement, syms.arrayClass);
3270 result.append(boxedArgs);
3271 } else {
3272 if (args.length() != 1) throw new AssertionError(args);
3273 JCExpression arg = translate(args.head, parameter);
3274 anyChanges |= (arg != args.head);
3275 result.append(arg);
3276 if (!anyChanges) return _args;
3277 }
3278 return result.toList();
3279 }
3280
3281 /** Expand a boxing or unboxing conversion if needed. */
3282 @SuppressWarnings("unchecked") // XXX unchecked
3283 <T extends JCExpression> T boxIfNeeded(T tree, Type type) {
3284 Assert.check(!type.hasTag(VOID));
3285 if (type.hasTag(NONE))
3286 return tree;
3287 boolean havePrimitive = tree.type.isPrimitive();
3288 if (havePrimitive == type.isPrimitive())
3289 return tree;
3290 if (havePrimitive) {
3291 Type unboxedTarget = types.unboxedType(type);
3292 if (!unboxedTarget.hasTag(NONE)) {
3293 if (!types.isSubtype(tree.type, unboxedTarget)) //e.g. Character c = 89;
3294 tree.type = unboxedTarget.constType(tree.type.constValue());
3295 return (T)boxPrimitive(tree, types.erasure(type));
3296 } else {
3297 tree = (T)boxPrimitive(tree);
3298 }
3299 } else {
3300 tree = (T)unbox(tree, type);
3301 }
3302 return tree;
3303 }
3304
3305 /** Box up a single primitive expression. */
3306 JCExpression boxPrimitive(JCExpression tree) {
3307 return boxPrimitive(tree, types.boxedClass(tree.type).type);
3308 }
3309
3310 /** Box up a single primitive expression. */
3311 JCExpression boxPrimitive(JCExpression tree, Type box) {
3312 make_at(tree.pos());
3313 Symbol valueOfSym = lookupMethod(tree.pos(),
3314 names.valueOf,
3315 box,
3316 List.<Type>nil()
3317 .prepend(tree.type));
3318 JCMethodInvocation res = make.App(make.QualIdent(valueOfSym), List.of(tree));
3319 res.boxingKind = JCMethodInvocation.BoxingKind.BOX;
3320 return res;
3321 }
3322
3323 /** Unbox an object to a primitive value. */
3324 JCExpression unbox(JCExpression tree, Type primitive) {
3325 Type unboxedType = types.unboxedType(tree.type);
3326 if (unboxedType.hasTag(NONE)) {
3327 unboxedType = primitive;
3328 if (!unboxedType.isPrimitive())
3329 throw new AssertionError(unboxedType);
3330 make_at(tree.pos());
3331 tree = make.TypeCast(types.boxedClass(unboxedType).type, tree);
3332 } else {
3333 // There must be a conversion from unboxedType to primitive.
3334 if (!types.isSubtype(unboxedType, primitive))
3335 throw new AssertionError(tree);
3336 }
3337 make_at(tree.pos());
3338 Symbol valueSym = lookupMethod(tree.pos(),
3339 unboxedType.tsym.name.append(names.Value), // x.intValue()
3340 tree.type,
3341 List.nil());
3342 JCMethodInvocation res = make.App(make.Select(tree, valueSym));
3343 res.boxingKind = JCMethodInvocation.BoxingKind.UNBOX;
3344 return res;
3345 }
3346
3347 /** Visitor method for parenthesized expressions.
3348 * If the subexpression has changed, omit the parens.
3349 */
3350 public void visitParens(JCParens tree) {
3351 JCTree expr = translate(tree.expr);
3352 result = ((expr == tree.expr) ? tree : expr);
3353 }
3354
3355 public void visitIndexed(JCArrayAccess tree) {
3356 tree.indexed = translate(tree.indexed);
3357 tree.index = translate(tree.index, syms.intType);
3358 result = tree;
3359 }
3360
3361 public void visitAssign(JCAssign tree) {
3362 tree.lhs = translate(tree.lhs, tree);
3363 tree.rhs = translate(tree.rhs, tree.lhs.type);
3364
3365 // If translated left hand side is an Apply, we are
3366 // seeing an access method invocation. In this case, append
3367 // right hand side as last argument of the access method.
3368 if (tree.lhs.hasTag(APPLY)) {
3369 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3370 app.args = List.of(tree.rhs).prependList(app.args);
3371 result = app;
3372 } else {
3373 result = tree;
3374 }
3375 }
3376
3377 public void visitAssignop(final JCAssignOp tree) {
3378 final boolean boxingReq = !tree.lhs.type.isPrimitive() &&
3379 tree.operator.type.getReturnType().isPrimitive();
3380
3381 AssignopDependencyScanner depScanner = new AssignopDependencyScanner(tree);
3382 depScanner.scan(tree.rhs);
3383
3384 if (boxingReq || depScanner.dependencyFound) {
3385 // boxing required; need to rewrite as x = (unbox typeof x)(x op y);
3386 // or if x == (typeof x)z then z = (unbox typeof x)((typeof x)z op y)
3387 // (but without recomputing x)
3388 JCTree newTree = abstractLval(tree.lhs, lhs -> {
3389 Tag newTag = tree.getTag().noAssignOp();
3390 // Erasure (TransTypes) can change the type of
3391 // tree.lhs. However, we can still get the
3392 // unerased type of tree.lhs as it is stored
3393 // in tree.type in Attr.
3394 OperatorSymbol newOperator = operators.resolveBinary(tree,
3395 newTag,
3396 tree.type,
3397 tree.rhs.type);
3398 //Need to use the "lhs" at two places, once on the future left hand side
3399 //and once in the future binary operator. But further processing may change
3400 //the components of the tree in place (see visitSelect for e.g. <Class>.super.<ident>),
3401 //so cloning the tree to avoid interference between the uses:
3402 JCExpression expr = (JCExpression) lhs.clone();
3403 if (expr.type != tree.type)
3404 expr = make.TypeCast(tree.type, expr);
3405 JCBinary opResult = make.Binary(newTag, expr, tree.rhs);
3406 opResult.operator = newOperator;
3407 opResult.type = newOperator.type.getReturnType();
3408 JCExpression newRhs = boxingReq ?
3409 make.TypeCast(types.unboxedType(tree.type), opResult) :
3410 opResult;
3411 return make.Assign(lhs, newRhs).setType(tree.type);
3412 });
3413 result = translate(newTree);
3414 return;
3415 }
3416 tree.lhs = translate(tree.lhs, tree);
3417 tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
3418
3419 // If translated left hand side is an Apply, we are
3420 // seeing an access method invocation. In this case, append
3421 // right hand side as last argument of the access method.
3422 if (tree.lhs.hasTag(APPLY)) {
3423 JCMethodInvocation app = (JCMethodInvocation)tree.lhs;
3424 // if operation is a += on strings,
3425 // make sure to convert argument to string
3426 JCExpression rhs = tree.operator.opcode == string_add
3427 ? makeString(tree.rhs)
3428 : tree.rhs;
3429 app.args = List.of(rhs).prependList(app.args);
3430 result = app;
3431 } else {
3432 result = tree;
3433 }
3434 }
3435
3436 class AssignopDependencyScanner extends TreeScanner {
3437
3438 Symbol sym;
3439 boolean dependencyFound = false;
3440
3441 AssignopDependencyScanner(JCAssignOp tree) {
3442 this.sym = TreeInfo.symbol(tree.lhs);
3443 }
3444
3445 @Override
3446 public void scan(JCTree tree) {
3447 if (tree != null && sym != null) {
3448 tree.accept(this);
3449 }
3450 }
3451
3452 @Override
3453 public void visitAssignop(JCAssignOp tree) {
3454 if (TreeInfo.symbol(tree.lhs) == sym) {
3455 dependencyFound = true;
3456 return;
3457 }
3458 super.visitAssignop(tree);
3459 }
3460
3461 @Override
3462 public void visitUnary(JCUnary tree) {
3463 if (TreeInfo.symbol(tree.arg) == sym) {
3464 dependencyFound = true;
3465 return;
3466 }
3467 super.visitUnary(tree);
3468 }
3469 }
3470
3471 /** Lower a tree of the form e++ or e-- where e is an object type */
3472 JCExpression lowerBoxedPostop(final JCUnary tree) {
3473 // translate to tmp1=lval(e); tmp2=tmp1; tmp1 OP 1; tmp2
3474 // or
3475 // translate to tmp1=lval(e); tmp2=tmp1; (typeof tree)tmp1 OP 1; tmp2
3476 // where OP is += or -=
3477 final boolean cast = TreeInfo.skipParens(tree.arg).hasTag(TYPECAST);
3478 return abstractLval(tree.arg, tmp1 -> abstractRval(tmp1, tree.arg.type, tmp2 -> {
3479 Tag opcode = (tree.hasTag(POSTINC))
3480 ? PLUS_ASG : MINUS_ASG;
3481 //"tmp1" and "tmp2" may refer to the same instance
3482 //(for e.g. <Class>.super.<ident>). But further processing may
3483 //change the components of the tree in place (see visitSelect),
3484 //so cloning the tree to avoid interference between the two uses:
3485 JCExpression lhs = (JCExpression)tmp1.clone();
3486 lhs = cast
3487 ? make.TypeCast(tree.arg.type, lhs)
3488 : lhs;
3489 JCExpression update = makeAssignop(opcode,
3490 lhs,
3491 make.Literal(1));
3492 return makeComma(update, tmp2);
3493 }));
3494 }
3495
3496 public void visitUnary(JCUnary tree) {
3497 boolean isUpdateOperator = tree.getTag().isIncOrDecUnaryOp();
3498 if (isUpdateOperator && !tree.arg.type.isPrimitive()) {
3499 switch(tree.getTag()) {
3500 case PREINC: // ++ e
3501 // translate to e += 1
3502 case PREDEC: // -- e
3503 // translate to e -= 1
3504 {
3505 JCTree.Tag opcode = (tree.hasTag(PREINC))
3506 ? PLUS_ASG : MINUS_ASG;
3507 JCAssignOp newTree = makeAssignop(opcode,
3508 tree.arg,
3509 make.Literal(1));
3510 result = translate(newTree, tree.type);
3511 return;
3512 }
3513 case POSTINC: // e ++
3514 case POSTDEC: // e --
3515 {
3516 result = translate(lowerBoxedPostop(tree), tree.type);
3517 return;
3518 }
3519 }
3520 throw new AssertionError(tree);
3521 }
3522
3523 tree.arg = boxIfNeeded(translate(tree.arg, tree), tree.type);
3524
3525 if (tree.hasTag(NOT) && tree.arg.type.constValue() != null) {
3526 tree.type = cfolder.fold1(bool_not, tree.arg.type);
3527 }
3528
3529 // If translated left hand side is an Apply, we are
3530 // seeing an access method invocation. In this case, return
3531 // that access method invocation as result.
3532 if (isUpdateOperator && tree.arg.hasTag(APPLY)) {
3533 result = tree.arg;
3534 } else {
3535 result = tree;
3536 }
3537 }
3538
3539 public void visitBinary(JCBinary tree) {
3540 List<Type> formals = tree.operator.type.getParameterTypes();
3541 JCTree lhs = tree.lhs = translate(tree.lhs, formals.head);
3542 switch (tree.getTag()) {
3543 case OR:
3544 if (isTrue(lhs)) {
3545 result = lhs;
3546 return;
3547 }
3548 if (isFalse(lhs)) {
3549 result = translate(tree.rhs, formals.tail.head);
3550 return;
3551 }
3552 break;
3553 case AND:
3554 if (isFalse(lhs)) {
3555 result = lhs;
3556 return;
3557 }
3558 if (isTrue(lhs)) {
3559 result = translate(tree.rhs, formals.tail.head);
3560 return;
3561 }
3562 break;
3563 }
3564 tree.rhs = translate(tree.rhs, formals.tail.head);
3565 result = tree;
3566 }
3567
3568 public void visitIdent(JCIdent tree) {
3569 result = access(tree.sym, tree, enclOp, false);
3570 }
3571
3572 /** Translate away the foreach loop. */
3573 public void visitForeachLoop(JCEnhancedForLoop tree) {
3574 if (types.elemtype(tree.expr.type) == null)
3575 visitIterableForeachLoop(tree);
3576 else
3577 visitArrayForeachLoop(tree);
3578 }
3579 // where
3580 /**
3581 * A statement of the form
3582 *
3583 * <pre>
3584 * for ( T v : arrayexpr ) stmt;
3585 * </pre>
3586 *
3587 * (where arrayexpr is of an array type) gets translated to
3588 *
3589 * <pre>{@code
3590 * for ( { arraytype #arr = arrayexpr;
3591 * int #len = array.length;
3592 * int #i = 0; };
3593 * #i < #len; i$++ ) {
3594 * T v = (T) arr$[#i];
3595 * stmt;
3596 * }
3597 * }</pre>
3598 *
3599 * where #arr, #len, and #i are freshly named synthetic local variables.
3600 */
3601 private void visitArrayForeachLoop(JCEnhancedForLoop tree) {
3602 make_at(tree.expr.pos());
3603 VarSymbol arraycache = new VarSymbol(SYNTHETIC,
3604 names.fromString("arr" + target.syntheticNameChar()),
3605 tree.expr.type,
3606 currentMethodSym);
3607 JCStatement arraycachedef = make.VarDef(arraycache, tree.expr);
3608 VarSymbol lencache = new VarSymbol(SYNTHETIC,
3609 names.fromString("len" + target.syntheticNameChar()),
3610 syms.intType,
3611 currentMethodSym);
3612 JCStatement lencachedef = make.
3613 VarDef(lencache, make.Select(make.Ident(arraycache), syms.lengthVar));
3614 VarSymbol index = new VarSymbol(SYNTHETIC,
3615 names.fromString("i" + target.syntheticNameChar()),
3616 syms.intType,
3617 currentMethodSym);
3618
3619 JCVariableDecl indexdef = make.VarDef(index, make.Literal(INT, 0));
3620 indexdef.init.type = indexdef.type = syms.intType.constType(0);
3621
3622 List<JCStatement> loopinit = List.of(arraycachedef, lencachedef, indexdef);
3623 JCBinary cond = makeBinary(LT, make.Ident(index), make.Ident(lencache));
3624
3625 JCExpressionStatement step = make.Exec(makeUnary(PREINC, make.Ident(index)));
3626
3627 Type elemtype = types.elemtype(tree.expr.type);
3628 JCExpression loopvarinit = make.Indexed(make.Ident(arraycache),
3629 make.Ident(index)).setType(elemtype);
3630 loopvarinit = transTypes.coerce(attrEnv, loopvarinit, tree.var.type);
3631 JCVariableDecl loopvardef = (JCVariableDecl)make.VarDef(tree.var.mods,
3632 tree.var.name,
3633 tree.var.vartype,
3634 loopvarinit).setType(tree.var.type);
3635 loopvardef.sym = tree.var.sym;
3636 JCBlock body = make.
3637 Block(0, List.of(loopvardef, tree.body));
3638
3639 result = translate(make.
3640 ForLoop(loopinit,
3641 cond,
3642 List.of(step),
3643 body));
3644 patchTargets(body, tree, result);
3645 }
3646 /** Patch up break and continue targets. */
3647 private void patchTargets(JCTree body, final JCTree src, final JCTree dest) {
3648 class Patcher extends TreeScanner {
3649 public void visitBreak(JCBreak tree) {
3650 if (tree.target == src)
3651 tree.target = dest;
3652 }
3653 public void visitYield(JCYield tree) {
3654 if (tree.target == src)
3655 tree.target = dest;
3656 scan(tree.value);
3657 }
3658 public void visitContinue(JCContinue tree) {
3659 if (tree.target == src)
3660 tree.target = dest;
3661 }
3662 public void visitClassDef(JCClassDecl tree) {}
3663 }
3664 new Patcher().scan(body);
3665 }
3666 /**
3667 * A statement of the form
3668 *
3669 * <pre>
3670 * for ( T v : coll ) stmt ;
3671 * </pre>
3672 *
3673 * (where coll implements {@code Iterable<? extends T>}) gets translated to
3674 *
3675 * <pre>{@code
3676 * for ( Iterator<? extends T> #i = coll.iterator(); #i.hasNext(); ) {
3677 * T v = (T) #i.next();
3678 * stmt;
3679 * }
3680 * }</pre>
3681 *
3682 * where #i is a freshly named synthetic local variable.
3683 */
3684 private void visitIterableForeachLoop(JCEnhancedForLoop tree) {
3685 make_at(tree.expr.pos());
3686 Type iteratorTarget = syms.objectType;
3687 Type iterableType = types.asSuper(types.cvarUpperBound(tree.expr.type),
3688 syms.iterableType.tsym);
3689 if (iterableType.getTypeArguments().nonEmpty())
3690 iteratorTarget = types.erasure(iterableType.getTypeArguments().head);
3691 tree.expr.type = types.erasure(types.skipTypeVars(tree.expr.type, false));
3692 tree.expr = transTypes.coerce(attrEnv, tree.expr, types.erasure(iterableType));
3693 Symbol iterator = lookupMethod(tree.expr.pos(),
3694 names.iterator,
3695 tree.expr.type,
3696 List.nil());
3697 Assert.check(types.isSameType(types.erasure(types.asSuper(iterator.type.getReturnType(), syms.iteratorType.tsym)), types.erasure(syms.iteratorType)));
3698 VarSymbol itvar = new VarSymbol(SYNTHETIC, names.fromString("i" + target.syntheticNameChar()),
3699 types.erasure(syms.iteratorType),
3700 currentMethodSym);
3701
3702 JCStatement init = make.
3703 VarDef(itvar, make.App(make.Select(tree.expr, iterator)
3704 .setType(types.erasure(iterator.type))));
3705
3706 Symbol hasNext = lookupMethod(tree.expr.pos(),
3707 names.hasNext,
3708 itvar.type,
3709 List.nil());
3710 JCMethodInvocation cond = make.App(make.Select(make.Ident(itvar), hasNext));
3711 Symbol next = lookupMethod(tree.expr.pos(),
3712 names.next,
3713 itvar.type,
3714 List.nil());
3715 JCExpression vardefinit = make.App(make.Select(make.Ident(itvar), next));
3716 if (tree.var.type.isPrimitive())
3717 vardefinit = make.TypeCast(types.cvarUpperBound(iteratorTarget), vardefinit);
3718 else
3719 vardefinit = transTypes.coerce(attrEnv, vardefinit, tree.var.type);
3720 JCVariableDecl indexDef = (JCVariableDecl)make.VarDef(tree.var.mods,
3721 tree.var.name,
3722 tree.var.vartype,
3723 vardefinit,
3724 tree.var.declKind).setType(tree.var.type);
3725 indexDef.sym = tree.var.sym;
3726 JCBlock body = make.Block(0, List.of(indexDef, tree.body));
3727 body.bracePos = TreeInfo.endPos(tree.body);
3728 result = translate(make.
3729 ForLoop(List.of(init),
3730 cond,
3731 List.nil(),
3732 body));
3733 patchTargets(body, tree, result);
3734 }
3735
3736 public void visitVarDef(JCVariableDecl tree) {
3737 MethodSymbol oldMethodSym = currentMethodSym;
3738 int prevVariableIndex = variableIndex;
3739 tree.mods = translate(tree.mods);
3740 tree.vartype = translate(tree.vartype);
3741 if (currentMethodSym == null) {
3742 // A class or instance field initializer.
3743 currentMethodSym =
3744 new MethodSymbol((tree.mods.flags&STATIC) | BLOCK,
3745 names.empty, null,
3746 currentClass);
3747 }
3748 try {
3749 if (tree.init != null) tree.init = translate(tree.init, tree.type);
3750 result = tree;
3751 } finally {
3752 currentMethodSym = oldMethodSym;
3753 variableIndex = prevVariableIndex;
3754 }
3755 }
3756
3757 public void visitBlock(JCBlock tree) {
3758 MethodSymbol oldMethodSym = currentMethodSym;
3759 if (currentMethodSym == null) {
3760 // Block is a static or instance initializer.
3761 currentMethodSym =
3762 new MethodSymbol(tree.flags | BLOCK,
3763 names.empty, null,
3764 currentClass);
3765 }
3766 int prevVariableIndex = variableIndex;
3767 try {
3768 variableIndex = 0;
3769 super.visitBlock(tree);
3770 } finally {
3771 currentMethodSym = oldMethodSym;
3772 variableIndex = prevVariableIndex;
3773 }
3774 }
3775
3776 public void visitDoLoop(JCDoWhileLoop tree) {
3777 tree.body = translate(tree.body);
3778 tree.cond = translate(tree.cond, syms.booleanType);
3779 result = tree;
3780 }
3781
3782 public void visitWhileLoop(JCWhileLoop tree) {
3783 tree.cond = translate(tree.cond, syms.booleanType);
3784 tree.body = translate(tree.body);
3785 result = tree;
3786 }
3787
3788 public void visitForLoop(JCForLoop tree) {
3789 tree.init = translate(tree.init);
3790 if (tree.cond != null)
3791 tree.cond = translate(tree.cond, syms.booleanType);
3792 tree.step = translate(tree.step);
3793 tree.body = translate(tree.body);
3794 result = tree;
3795 }
3796
3797 public void visitReturn(JCReturn tree) {
3798 if (tree.expr != null)
3799 tree.expr = translate(tree.expr,
3800 currentRestype);
3801 result = tree;
3802 }
3803
3804 @Override
3805 public void visitLambda(JCLambda tree) {
3806 Type prevRestype = currentRestype;
3807 try {
3808 currentRestype = types.erasure(tree.getDescriptorType(types)).getReturnType();
3809 // represent void results as NO_TYPE, to avoid unnecessary boxing in boxIfNeeded
3810 if (currentRestype.hasTag(VOID))
3811 currentRestype = Type.noType;
3812 tree.body = tree.getBodyKind() == BodyKind.EXPRESSION ?
3813 translate((JCExpression) tree.body, currentRestype) :
3814 translate(tree.body);
3815 } finally {
3816 currentRestype = prevRestype;
3817 }
3818 result = tree;
3819 }
3820
3821 public void visitSwitch(JCSwitch tree) {
3822 List<JCCase> cases = tree.patternSwitch ? addDefaultIfNeeded(tree.patternSwitch,
3823 tree.wasEnumSelector,
3824 tree.cases)
3825 : tree.cases;
3826 handleSwitch(tree, tree.selector, cases);
3827 }
3828
3829 @Override
3830 public void visitSwitchExpression(JCSwitchExpression tree) {
3831 List<JCCase> cases = addDefaultIfNeeded(tree.patternSwitch, tree.wasEnumSelector, tree.cases);
3832 handleSwitch(tree, tree.selector, cases);
3833 }
3834
3835 private List<JCCase> addDefaultIfNeeded(boolean patternSwitch, boolean wasEnumSelector,
3836 List<JCCase> cases) {
3837 if (cases.stream().flatMap(c -> c.labels.stream()).noneMatch(p -> p.hasTag(Tag.DEFAULTCASELABEL))) {
3838 boolean matchException = useMatchException;
3839 matchException |= patternSwitch && !wasEnumSelector;
3840 Type exception = matchException ? syms.matchExceptionType
3841 : syms.incompatibleClassChangeErrorType;
3842 List<JCExpression> params = matchException ? List.of(makeNull(), makeNull())
3843 : List.nil();
3844 JCThrow thr = make.Throw(makeNewClass(exception, params));
3845 JCCase c = make.Case(JCCase.STATEMENT, List.of(make.DefaultCaseLabel()), null, List.of(thr), null);
3846 cases = cases.prepend(c);
3847 }
3848
3849 return cases;
3850 }
3851
3852 private void handleSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
3853 //expand multiple label cases:
3854 ListBuffer<JCCase> convertedCases = new ListBuffer<>();
3855
3856 for (JCCase c : cases) {
3857 switch (c.labels.size()) {
3858 case 0: //default
3859 case 1: //single label
3860 convertedCases.append(c);
3861 break;
3862 default: //multiple labels, expand:
3863 //case C1, C2, C3: ...
3864 //=>
3865 //case C1:
3866 //case C2:
3867 //case C3: ...
3868 List<JCCaseLabel> patterns = c.labels;
3869 while (patterns.tail.nonEmpty()) {
3870 convertedCases.append(make_at(c.pos()).Case(JCCase.STATEMENT,
3871 List.of(patterns.head),
3872 null,
3873 List.nil(),
3874 null));
3875 patterns = patterns.tail;
3876 }
3877 c.labels = patterns;
3878 convertedCases.append(c);
3879 break;
3880 }
3881 }
3882
3883 for (JCCase c : convertedCases) {
3884 if (c.caseKind == JCCase.RULE && c.completesNormally) {
3885 JCBreak b = make.at(TreeInfo.endPos(c.stats.last())).Break(null);
3886 b.target = tree;
3887 c.stats = c.stats.append(b);
3888 }
3889 }
3890
3891 cases = convertedCases.toList();
3892
3893 Type selsuper = types.supertype(selector.type);
3894 boolean enumSwitch = selsuper != null &&
3895 (selector.type.tsym.flags() & ENUM) != 0;
3896 boolean stringSwitch = selsuper != null &&
3897 types.isSameType(selector.type, syms.stringType);
3898 boolean boxedSwitch = !enumSwitch && !stringSwitch && !selector.type.isPrimitive();
3899 selector = translate(selector, selector.type);
3900 cases = translateCases(cases);
3901 if (tree.hasTag(SWITCH)) {
3902 ((JCSwitch) tree).selector = selector;
3903 ((JCSwitch) tree).cases = cases;
3904 } else if (tree.hasTag(SWITCH_EXPRESSION)) {
3905 ((JCSwitchExpression) tree).selector = selector;
3906 ((JCSwitchExpression) tree).cases = cases;
3907 } else {
3908 Assert.error();
3909 }
3910 if (enumSwitch) {
3911 result = visitEnumSwitch(tree, selector, cases);
3912 } else if (stringSwitch) {
3913 result = visitStringSwitch(tree, selector, cases);
3914 } else if (boxedSwitch) {
3915 //An switch over boxed primitive. Pattern matching switches are already translated
3916 //by TransPatterns, so all non-primitive types are only boxed primitives:
3917 result = visitBoxedPrimitiveSwitch(tree, selector, cases);
3918 } else {
3919 result = tree;
3920 }
3921 }
3922
3923 public JCTree visitEnumSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
3924 TypeSymbol enumSym = selector.type.tsym;
3925 EnumMapping map = mapForEnum(tree.pos(), enumSym);
3926 make_at(tree.pos());
3927 Symbol ordinalMethod = lookupMethod(tree.pos(),
3928 names.ordinal,
3929 selector.type,
3930 List.nil());
3931 JCExpression newSelector;
3932
3933 if (cases.stream().anyMatch(c -> TreeInfo.isNullCaseLabel(c.labels.head))) {
3934 //for enum switches with case null, do:
3935 //switch ($selector != null ? $mapVar[$selector.ordinal()] : -1) {...}
3936 //replacing case null with case -1:
3937 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
3938 names.fromString("s" + variableIndex++ + this.target.syntheticNameChar()),
3939 selector.type,
3940 currentMethodSym);
3941 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type);
3942 newSelector = map.switchValue(
3943 make.App(make.Select(make.Ident(dollar_s),
3944 ordinalMethod)));
3945 newSelector =
3946 make.LetExpr(List.of(var),
3947 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()),
3948 newSelector,
3949 makeLit(syms.intType, -1))
3950 .setType(newSelector.type))
3951 .setType(newSelector.type);
3952 } else {
3953 newSelector = map.switchValue(
3954 make.App(make.Select(selector,
3955 ordinalMethod)));
3956 }
3957 ListBuffer<JCCase> newCases = new ListBuffer<>();
3958 for (JCCase c : cases) {
3959 if (c.labels.head.hasTag(CONSTANTCASELABEL)) {
3960 JCExpression pat;
3961 if (TreeInfo.isNullCaseLabel(c.labels.head)) {
3962 pat = makeLit(syms.intType, -1);
3963 } else {
3964 VarSymbol label = (VarSymbol)TreeInfo.symbol(((JCConstantCaseLabel) c.labels.head).expr);
3965 pat = map.caseValue(label);
3966 }
3967 newCases.append(make.Case(JCCase.STATEMENT, List.of(make.ConstantCaseLabel(pat)), null, c.stats, null));
3968 } else {
3969 newCases.append(c);
3970 }
3971 }
3972 JCTree enumSwitch;
3973 if (tree.hasTag(SWITCH)) {
3974 enumSwitch = make.Switch(newSelector, newCases.toList());
3975 } else if (tree.hasTag(SWITCH_EXPRESSION)) {
3976 enumSwitch = make.SwitchExpression(newSelector, newCases.toList());
3977 enumSwitch.setType(tree.type);
3978 } else {
3979 Assert.error();
3980 throw new AssertionError();
3981 }
3982 patchTargets(enumSwitch, tree, enumSwitch);
3983 return enumSwitch;
3984 }
3985
3986 public JCTree visitStringSwitch(JCTree tree, JCExpression selector, List<JCCase> caseList) {
3987 int alternatives = caseList.size();
3988
3989 if (alternatives == 0) { // Strange but legal possibility (only legal for switch statement)
3990 return make.at(tree.pos()).Exec(attr.makeNullCheck(selector));
3991 } else {
3992 /*
3993 * The general approach used is to translate a single
3994 * string switch statement into a series of two chained
3995 * switch statements: the first a synthesized statement
3996 * switching on the argument string's hash value and
3997 * computing a string's position in the list of original
3998 * case labels, if any, followed by a second switch on the
3999 * computed integer value. The second switch has the same
4000 * code structure as the original string switch statement
4001 * except that the string case labels are replaced with
4002 * positional integer constants starting at 0.
4003 *
4004 * The first switch statement can be thought of as an
4005 * inlined map from strings to their position in the case
4006 * label list. An alternate implementation would use an
4007 * actual Map for this purpose, as done for enum switches.
4008 *
4009 * With some additional effort, it would be possible to
4010 * use a single switch statement on the hash code of the
4011 * argument, but care would need to be taken to preserve
4012 * the proper control flow in the presence of hash
4013 * collisions and other complications, such as
4014 * fallthroughs. Switch statements with one or two
4015 * alternatives could also be specially translated into
4016 * if-then statements to omit the computation of the hash
4017 * code.
4018 *
4019 * The generated code assumes that the hashing algorithm
4020 * of String is the same in the compilation environment as
4021 * in the environment the code will run in. The string
4022 * hashing algorithm in the SE JDK has been unchanged
4023 * since at least JDK 1.2. Since the algorithm has been
4024 * specified since that release as well, it is very
4025 * unlikely to be changed in the future.
4026 *
4027 * Different hashing algorithms, such as the length of the
4028 * strings or a perfect hashing algorithm over the
4029 * particular set of case labels, could potentially be
4030 * used instead of String.hashCode.
4031 */
4032
4033 ListBuffer<JCStatement> stmtList = new ListBuffer<>();
4034
4035 // Map from String case labels to their original position in
4036 // the list of case labels.
4037 Map<String, Integer> caseLabelToPosition = new LinkedHashMap<>(alternatives + 1, 1.0f);
4038
4039 // Map of hash codes to the string case labels having that hashCode.
4040 Map<Integer, Set<String>> hashToString = new LinkedHashMap<>(alternatives + 1, 1.0f);
4041
4042 int casePosition = 0;
4043 JCCase nullCase = null;
4044 int nullCaseLabel = -1;
4045
4046 for(JCCase oneCase : caseList) {
4047 if (oneCase.labels.head.hasTag(CONSTANTCASELABEL)) {
4048 if (TreeInfo.isNullCaseLabel(oneCase.labels.head)) {
4049 nullCase = oneCase;
4050 nullCaseLabel = casePosition;
4051 } else {
4052 JCExpression expression = ((JCConstantCaseLabel) oneCase.labels.head).expr;
4053 String labelExpr = (String) expression.type.constValue();
4054 Integer mapping = caseLabelToPosition.put(labelExpr, casePosition);
4055 Assert.checkNull(mapping);
4056 int hashCode = labelExpr.hashCode();
4057
4058 Set<String> stringSet = hashToString.get(hashCode);
4059 if (stringSet == null) {
4060 stringSet = new LinkedHashSet<>(1, 1.0f);
4061 stringSet.add(labelExpr);
4062 hashToString.put(hashCode, stringSet);
4063 } else {
4064 boolean added = stringSet.add(labelExpr);
4065 Assert.check(added);
4066 }
4067 }
4068 }
4069 casePosition++;
4070 }
4071
4072 // Synthesize a switch statement that has the effect of
4073 // mapping from a string to the integer position of that
4074 // string in the list of case labels. This is done by
4075 // switching on the hashCode of the string followed by an
4076 // if-then-else chain comparing the input for equality
4077 // with all the case labels having that hash value.
4078
4079 /*
4080 * s$ = top of stack;
4081 * tmp$ = -1;
4082 * switch($s.hashCode()) {
4083 * case caseLabel.hashCode:
4084 * if (s$.equals("caseLabel_1")
4085 * tmp$ = caseLabelToPosition("caseLabel_1");
4086 * else if (s$.equals("caseLabel_2"))
4087 * tmp$ = caseLabelToPosition("caseLabel_2");
4088 * ...
4089 * break;
4090 * ...
4091 * }
4092 */
4093
4094 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
4095 names.fromString("s" + variableIndex++ + target.syntheticNameChar()),
4096 syms.stringType,
4097 currentMethodSym);
4098 stmtList.append(make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type));
4099
4100 VarSymbol dollar_tmp = new VarSymbol(SYNTHETIC,
4101 names.fromString("tmp" + variableIndex++ + target.syntheticNameChar()),
4102 syms.intType,
4103 currentMethodSym);
4104 JCVariableDecl dollar_tmp_def =
4105 (JCVariableDecl)make.VarDef(dollar_tmp, make.Literal(INT, -1)).setType(dollar_tmp.type);
4106 dollar_tmp_def.init.type = dollar_tmp.type = syms.intType;
4107 stmtList.append(dollar_tmp_def);
4108 ListBuffer<JCCase> caseBuffer = new ListBuffer<>();
4109 // hashCode will trigger nullcheck on original switch expression
4110 JCMethodInvocation hashCodeCall = makeCall(make.Ident(dollar_s),
4111 names.hashCode,
4112 List.nil()).setType(syms.intType);
4113 JCSwitch switch1 = make.Switch(hashCodeCall,
4114 caseBuffer.toList());
4115 for(Map.Entry<Integer, Set<String>> entry : hashToString.entrySet()) {
4116 int hashCode = entry.getKey();
4117 Set<String> stringsWithHashCode = entry.getValue();
4118 Assert.check(stringsWithHashCode.size() >= 1);
4119
4120 JCStatement elsepart = null;
4121 for(String caseLabel : stringsWithHashCode ) {
4122 JCMethodInvocation stringEqualsCall = makeCall(make.Ident(dollar_s),
4123 names.equals,
4124 List.of(make.Literal(caseLabel)));
4125 elsepart = make.If(stringEqualsCall,
4126 make.Exec(make.Assign(make.Ident(dollar_tmp),
4127 make.Literal(caseLabelToPosition.get(caseLabel))).
4128 setType(dollar_tmp.type)),
4129 elsepart);
4130 }
4131
4132 ListBuffer<JCStatement> lb = new ListBuffer<>();
4133 JCBreak breakStmt = make.Break(null);
4134 breakStmt.target = switch1;
4135 lb.append(elsepart).append(breakStmt);
4136
4137 caseBuffer.append(make.Case(JCCase.STATEMENT,
4138 List.of(make.ConstantCaseLabel(make.Literal(hashCode))),
4139 null,
4140 lb.toList(),
4141 null));
4142 }
4143
4144 switch1.cases = caseBuffer.toList();
4145
4146 if (nullCase != null) {
4147 stmtList.append(make.If(makeBinary(NE, make.Ident(dollar_s), makeNull()), switch1, make.Exec(make.Assign(make.Ident(dollar_tmp),
4148 make.Literal(nullCaseLabel)).
4149 setType(dollar_tmp.type))).setType(syms.intType));
4150 } else {
4151 stmtList.append(switch1);
4152 }
4153
4154 // Make isomorphic switch tree replacing string labels
4155 // with corresponding integer ones from the label to
4156 // position map.
4157
4158 ListBuffer<JCCase> lb = new ListBuffer<>();
4159 for(JCCase oneCase : caseList ) {
4160 boolean isDefault = !oneCase.labels.head.hasTag(CONSTANTCASELABEL);
4161 JCExpression caseExpr;
4162 if (isDefault)
4163 caseExpr = null;
4164 else if (oneCase == nullCase) {
4165 caseExpr = make.Literal(nullCaseLabel);
4166 } else {
4167 JCExpression expression = ((JCConstantCaseLabel) oneCase.labels.head).expr;
4168 String name = (String) TreeInfo.skipParens(expression)
4169 .type.constValue();
4170 caseExpr = make.Literal(caseLabelToPosition.get(name));
4171 }
4172
4173 lb.append(make.Case(JCCase.STATEMENT, caseExpr == null ? List.of(make.DefaultCaseLabel())
4174 : List.of(make.ConstantCaseLabel(caseExpr)),
4175 null,
4176 oneCase.stats, null));
4177 }
4178
4179 if (tree.hasTag(SWITCH)) {
4180 JCSwitch switch2 = make.Switch(make.Ident(dollar_tmp), lb.toList());
4181 // Rewire up old unlabeled break statements to the
4182 // replacement switch being created.
4183 patchTargets(switch2, tree, switch2);
4184
4185 stmtList.append(switch2);
4186
4187 JCBlock res = make.Block(0L, stmtList.toList());
4188 res.bracePos = TreeInfo.endPos(tree);
4189 return res;
4190 } else {
4191 JCSwitchExpression switch2 = make.SwitchExpression(make.Ident(dollar_tmp), lb.toList());
4192
4193 // Rewire up old unlabeled break statements to the
4194 // replacement switch being created.
4195 patchTargets(switch2, tree, switch2);
4196
4197 switch2.setType(tree.type);
4198
4199 LetExpr res = make.LetExpr(stmtList.toList(), switch2);
4200
4201 res.needsCond = true;
4202 res.setType(tree.type);
4203
4204 return res;
4205 }
4206 }
4207 }
4208
4209 private JCTree visitBoxedPrimitiveSwitch(JCTree tree, JCExpression selector, List<JCCase> cases) {
4210 JCExpression newSelector;
4211
4212 if (cases.stream().anyMatch(c -> TreeInfo.isNullCaseLabel(c.labels.head))) {
4213 //a switch over a boxed primitive, with a null case. Pick two constants that are
4214 //not used by any branch in the case (c1 and c2), close to other constants that are
4215 //used in the switch. Then do:
4216 //switch ($selector != null ? $selector != c1 ? $selector : c2 : c1) {...}
4217 //replacing case null with case c1
4218 Set<Integer> constants = new LinkedHashSet<>();
4219 JCCase nullCase = null;
4220
4221 for (JCCase c : cases) {
4222 if (TreeInfo.isNullCaseLabel(c.labels.head)) {
4223 nullCase = c;
4224 } else if (!c.labels.head.hasTag(DEFAULTCASELABEL)) {
4225 constants.add((int) ((JCConstantCaseLabel) c.labels.head).expr.type.constValue());
4226 }
4227 }
4228
4229 Assert.checkNonNull(nullCase);
4230
4231 int nullValue = constants.isEmpty() ? 0 : constants.iterator().next();
4232
4233 while (constants.contains(nullValue)) nullValue++;
4234
4235 constants.add(nullValue);
4236 nullCase.labels.head = make.ConstantCaseLabel(makeLit(syms.intType, nullValue));
4237
4238 int replacementValue = nullValue;
4239
4240 while (constants.contains(replacementValue)) replacementValue++;
4241
4242 VarSymbol dollar_s = new VarSymbol(FINAL|SYNTHETIC,
4243 names.fromString("s" + variableIndex++ + this.target.syntheticNameChar()),
4244 selector.type,
4245 currentMethodSym);
4246 JCStatement var = make.at(tree.pos()).VarDef(dollar_s, selector).setType(dollar_s.type);
4247 JCExpression nullValueReplacement =
4248 make.Conditional(makeBinary(NE,
4249 unbox(make.Ident(dollar_s), syms.intType),
4250 makeLit(syms.intType, nullValue)),
4251 unbox(make.Ident(dollar_s), syms.intType),
4252 makeLit(syms.intType, replacementValue))
4253 .setType(syms.intType);
4254 JCExpression nullCheck =
4255 make.Conditional(makeBinary(NE, make.Ident(dollar_s), makeNull()),
4256 nullValueReplacement,
4257 makeLit(syms.intType, nullValue))
4258 .setType(syms.intType);
4259 newSelector = make.LetExpr(List.of(var), nullCheck).setType(syms.intType);
4260 } else {
4261 newSelector = unbox(selector, syms.intType);
4262 }
4263
4264 if (tree.hasTag(SWITCH)) {
4265 ((JCSwitch) tree).selector = newSelector;
4266 } else {
4267 ((JCSwitchExpression) tree).selector = newSelector;
4268 }
4269
4270 return tree;
4271 }
4272
4273 @Override
4274 public void visitBreak(JCBreak tree) {
4275 result = tree;
4276 }
4277
4278 @Override
4279 public void visitYield(JCYield tree) {
4280 tree.value = translate(tree.value, tree.target.type);
4281 result = tree;
4282 }
4283
4284 public void visitNewArray(JCNewArray tree) {
4285 tree.elemtype = translate(tree.elemtype);
4286 for (List<JCExpression> t = tree.dims; t.tail != null; t = t.tail)
4287 if (t.head != null) t.head = translate(t.head, syms.intType);
4288 tree.elems = translate(tree.elems, types.elemtype(tree.type));
4289 result = tree;
4290 }
4291
4292 public void visitSelect(JCFieldAccess tree) {
4293 // need to special case-access of the form C.super.x
4294 // these will always need an access method, unless C
4295 // is a default interface subclassed by the current class.
4296 boolean qualifiedSuperAccess =
4297 tree.selected.hasTag(SELECT) &&
4298 TreeInfo.name(tree.selected) == names._super &&
4299 !types.isDirectSuperInterface(((JCFieldAccess)tree.selected).selected.type.tsym, currentClass);
4300 tree.selected = translate(tree.selected);
4301 if (tree.name == names._class && tree.selected.type.isPrimitiveOrVoid()) {
4302 result = classOf(tree.selected);
4303 }
4304 else if (tree.name == names._super &&
4305 types.isDirectSuperInterface(tree.selected.type.tsym, currentClass)) {
4306 //default super call!! Not a classic qualified super call
4307 TypeSymbol supSym = tree.selected.type.tsym;
4308 Assert.checkNonNull(types.asSuper(currentClass.type, supSym));
4309 result = tree;
4310 }
4311 else if (tree.name == names._this || tree.name == names._super) {
4312 result = makeThis(tree.pos(), tree.selected.type.tsym);
4313 }
4314 else
4315 result = access(tree.sym, tree, enclOp, qualifiedSuperAccess);
4316 }
4317
4318 public void visitLetExpr(LetExpr tree) {
4319 tree.defs = translate(tree.defs);
4320 tree.expr = translate(tree.expr, tree.type);
4321 result = tree;
4322 }
4323
4324 // There ought to be nothing to rewrite here;
4325 // we don't generate code.
4326 public void visitAnnotation(JCAnnotation tree) {
4327 result = tree;
4328 }
4329
4330 @Override
4331 public void visitTry(JCTry tree) {
4332 if (tree.resources.nonEmpty()) {
4333 result = makeTwrTry(tree);
4334 return;
4335 }
4336
4337 boolean hasBody = tree.body.getStatements().nonEmpty();
4338 boolean hasCatchers = tree.catchers.nonEmpty();
4339 boolean hasFinally = tree.finalizer != null &&
4340 tree.finalizer.getStatements().nonEmpty();
4341
4342 if (!hasCatchers && !hasFinally) {
4343 result = translate(tree.body);
4344 return;
4345 }
4346
4347 if (!hasBody) {
4348 if (hasFinally) {
4349 result = translate(tree.finalizer);
4350 } else {
4351 result = translate(tree.body);
4352 }
4353 return;
4354 }
4355
4356 // no optimizations possible
4357 super.visitTry(tree);
4358 }
4359
4360 /* ************************************************************************
4361 * main method
4362 *************************************************************************/
4363
4364 /** Translate a toplevel class and return a list consisting of
4365 * the translated class and translated versions of all inner classes.
4366 * @param env The attribution environment current at the class definition.
4367 * We need this for resolving some additional symbols.
4368 * @param cdef The tree representing the class definition.
4369 */
4370 public List<JCTree> translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) {
4371 ListBuffer<JCTree> translated = null;
4372 try {
4373 attrEnv = env;
4374 this.make = make;
4375 currentClass = null;
4376 currentRestype = null;
4377 currentMethodDef = null;
4378 outermostClassDef = (cdef.hasTag(CLASSDEF)) ? (JCClassDecl)cdef : null;
4379 outermostMemberDef = null;
4380 this.translated = new ListBuffer<>();
4381 classdefs = new HashMap<>();
4382 actualSymbols = new HashMap<>();
4383 freevarCache = new HashMap<>();
4384 proxies = new HashMap<>();
4385 twrVars = WriteableScope.create(syms.noSymbol);
4386 outerThisStack = List.nil();
4387 accessNums = new HashMap<>();
4388 accessSyms = new HashMap<>();
4389 accessConstrs = new HashMap<>();
4390 accessConstrTags = List.nil();
4391 accessed = new ListBuffer<>();
4392 translate(cdef, (JCExpression)null);
4393 for (List<Symbol> l = accessed.toList(); l.nonEmpty(); l = l.tail)
4394 makeAccessible(l.head);
4395 for (EnumMapping map : enumSwitchMap.values())
4396 map.translate();
4397 checkConflicts(this.translated.toList());
4398 checkAccessConstructorTags();
4399 translated = this.translated;
4400 } finally {
4401 // note that recursive invocations of this method fail hard
4402 attrEnv = null;
4403 this.make = null;
4404 currentClass = null;
4405 currentRestype = null;
4406 currentMethodDef = null;
4407 outermostClassDef = null;
4408 outermostMemberDef = null;
4409 this.translated = null;
4410 classdefs = null;
4411 actualSymbols = null;
4412 freevarCache = null;
4413 proxies = null;
4414 outerThisStack = null;
4415 accessNums = null;
4416 accessSyms = null;
4417 accessConstrs = null;
4418 accessConstrTags = null;
4419 accessed = null;
4420 enumSwitchMap.clear();
4421 assertionsDisabledClassCache = null;
4422 }
4423 return translated.toList();
4424 }
4425
4426 // needed for the lambda deserialization method, which is expressed as a big switch on strings
4427 public JCMethodDecl translateMethod(Env<AttrContext> env, JCMethodDecl methodDecl, TreeMaker make) {
4428 try {
4429 this.attrEnv = env;
4430 this.make = make;
4431 this.currentClass = methodDecl.sym.enclClass();
4432 proxies = new HashMap<>();
4433 return translate(methodDecl);
4434 } finally {
4435 this.attrEnv = null;
4436 this.make = null;
4437 this.currentClass = null;
4438 // the two fields below are set when visiting the method
4439 this.currentMethodSym = null;
4440 this.currentMethodDef = null;
4441 this.proxies = null;
4442 }
4443 }
4444 }