1 /*
2 * Copyright (c) 2010, 2022, 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 com.sun.tools.javac.code.Symbol.MethodHandleSymbol;
29 import com.sun.tools.javac.code.Types.SignatureGenerator.InvalidSignatureException;
30 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
31 import com.sun.tools.javac.resources.CompilerProperties.Errors;
32 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
33 import com.sun.tools.javac.tree.*;
34 import com.sun.tools.javac.tree.JCTree.*;
35 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
36 import com.sun.tools.javac.tree.TreeMaker;
37 import com.sun.tools.javac.tree.TreeTranslator;
38 import com.sun.tools.javac.code.Attribute;
39 import com.sun.tools.javac.code.Symbol;
40 import com.sun.tools.javac.code.Symbol.ClassSymbol;
41 import com.sun.tools.javac.code.Symbol.DynamicMethodSymbol;
42 import com.sun.tools.javac.code.Symbol.MethodSymbol;
43 import com.sun.tools.javac.code.Symbol.TypeSymbol;
44 import com.sun.tools.javac.code.Symbol.VarSymbol;
45 import com.sun.tools.javac.code.Symtab;
46 import com.sun.tools.javac.code.Type;
47 import com.sun.tools.javac.code.Type.MethodType;
48 import com.sun.tools.javac.code.Type.TypeVar;
49 import com.sun.tools.javac.code.Types;
50 import com.sun.tools.javac.comp.LambdaToMethod.LambdaAnalyzerPreprocessor.*;
51 import com.sun.tools.javac.comp.Lower.BasicFreeVarCollector;
52 import com.sun.tools.javac.resources.CompilerProperties.Notes;
53 import com.sun.tools.javac.jvm.*;
54 import com.sun.tools.javac.util.*;
55 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
56 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
57
58 import java.util.EnumMap;
59 import java.util.HashMap;
60 import java.util.HashSet;
61 import java.util.LinkedHashMap;
62 import java.util.Map;
63 import java.util.Optional;
64 import java.util.Set;
65 import java.util.function.Consumer;
66 import java.util.function.Supplier;
67
68 import static com.sun.tools.javac.comp.LambdaToMethod.LambdaSymbolKind.*;
69 import static com.sun.tools.javac.code.Flags.*;
70 import static com.sun.tools.javac.code.Kinds.Kind.*;
71 import static com.sun.tools.javac.code.TypeTag.*;
72 import static com.sun.tools.javac.tree.JCTree.Tag.*;
73
74 import javax.lang.model.element.ElementKind;
75 import javax.lang.model.type.TypeKind;
76
77 import com.sun.tools.javac.main.Option;
78
79 /**
80 * This pass desugars lambda expressions into static methods
81 *
82 * <p><b>This is NOT part of any supported API.
83 * If you write code that depends on this, you do so at your own risk.
84 * This code and its internal interfaces are subject to change or
85 * deletion without notice.</b>
86 */
87 public class LambdaToMethod extends TreeTranslator {
88
89 private Attr attr;
90 private JCDiagnostic.Factory diags;
91 private Log log;
92 private Lower lower;
93 private Names names;
94 private Symtab syms;
95 private Resolve rs;
96 private Operators operators;
97 private TreeMaker make;
98 private Types types;
99 private TransTypes transTypes;
100 private Env<AttrContext> attrEnv;
101
102 /** the analyzer scanner */
103 private LambdaAnalyzerPreprocessor analyzer;
104
105 /** map from lambda trees to translation contexts */
106 private Map<JCTree, TranslationContext<?>> contextMap;
107
108 /** current translation context (visitor argument) */
109 private TranslationContext<?> context;
110
111 /** info about the current class being processed */
112 private KlassInfo kInfo;
113
114 /** dump statistics about lambda code generation */
115 private final boolean dumpLambdaToMethodStats;
116
117 /** force serializable representation, for stress testing **/
118 private final boolean forceSerializable;
119
120 /** true if line or local variable debug info has been requested */
121 private final boolean debugLinesOrVars;
122
123 /** dump statistics about lambda method deduplication */
124 private final boolean verboseDeduplication;
125
126 /** deduplicate lambda implementation methods */
127 private final boolean deduplicateLambdas;
128
129 /** lambda proxy is a dynamic nestmate */
130 private final boolean nestmateLambdas;
131
132 /** Flag for alternate metafactories indicating the lambda object is intended to be serializable */
133 public static final int FLAG_SERIALIZABLE = 1 << 0;
134
135 /** Flag for alternate metafactories indicating the lambda object has multiple targets */
136 public static final int FLAG_MARKERS = 1 << 1;
137
138 /** Flag for alternate metafactories indicating the lambda object requires multiple bridges */
139 public static final int FLAG_BRIDGES = 1 << 2;
140
141 // <editor-fold defaultstate="collapsed" desc="Instantiating">
142 protected static final Context.Key<LambdaToMethod> unlambdaKey = new Context.Key<>();
143
144 public static LambdaToMethod instance(Context context) {
145 LambdaToMethod instance = context.get(unlambdaKey);
146 if (instance == null) {
147 instance = new LambdaToMethod(context);
148 }
149 return instance;
150 }
151 private LambdaToMethod(Context context) {
152 context.put(unlambdaKey, this);
153 diags = JCDiagnostic.Factory.instance(context);
154 log = Log.instance(context);
155 lower = Lower.instance(context);
156 names = Names.instance(context);
157 syms = Symtab.instance(context);
158 rs = Resolve.instance(context);
159 operators = Operators.instance(context);
160 make = TreeMaker.instance(context);
161 types = Types.instance(context);
162 transTypes = TransTypes.instance(context);
163 analyzer = new LambdaAnalyzerPreprocessor();
164 Options options = Options.instance(context);
165 dumpLambdaToMethodStats = options.isSet("debug.dumpLambdaToMethodStats");
166 attr = Attr.instance(context);
167 forceSerializable = options.isSet("forceSerializable");
168 boolean lineDebugInfo =
169 options.isUnset(Option.G_CUSTOM) ||
170 options.isSet(Option.G_CUSTOM, "lines");
171 boolean varDebugInfo =
172 options.isUnset(Option.G_CUSTOM)
173 ? options.isSet(Option.G)
174 : options.isSet(Option.G_CUSTOM, "vars");
175 debugLinesOrVars = lineDebugInfo || varDebugInfo;
176 verboseDeduplication = options.isSet("debug.dumpLambdaToMethodDeduplication");
177 deduplicateLambdas = options.getBoolean("deduplicateLambdas", true);
178 nestmateLambdas = Target.instance(context).runtimeUseNestAccess();
179 }
180 // </editor-fold>
181
182 class DedupedLambda {
183 private final MethodSymbol symbol;
184 private final JCTree tree;
185
186 private int hashCode;
187
188 DedupedLambda(MethodSymbol symbol, JCTree tree) {
189 this.symbol = symbol;
190 this.tree = tree;
191 }
192
193
194 @Override
195 public int hashCode() {
196 int hashCode = this.hashCode;
197 if (hashCode == 0) {
198 this.hashCode = hashCode = TreeHasher.hash(tree, symbol.params());
199 }
200 return hashCode;
201 }
202
203 @Override
204 public boolean equals(Object o) {
205 return (o instanceof DedupedLambda dedupedLambda)
206 && types.isSameType(symbol.asType(), dedupedLambda.symbol.asType())
207 && new TreeDiffer(symbol.params(), dedupedLambda.symbol.params()).scan(tree, dedupedLambda.tree);
208 }
209 }
210
211 private class KlassInfo {
212
213 /**
214 * list of methods to append
215 */
216 private ListBuffer<JCTree> appendedMethodList;
217
218 private Map<DedupedLambda, DedupedLambda> dedupedLambdas;
219
220 private Map<Object, DynamicMethodSymbol> dynMethSyms = new HashMap<>();
221
222 /**
223 * list of deserialization cases
224 */
225 private final Map<String, ListBuffer<JCStatement>> deserializeCases;
226
227 /**
228 * deserialize method symbol
229 */
230 private final MethodSymbol deserMethodSym;
231
232 /**
233 * deserialize method parameter symbol
234 */
235 private final VarSymbol deserParamSym;
236
237 private final JCClassDecl clazz;
238
239 private KlassInfo(JCClassDecl clazz) {
240 this.clazz = clazz;
241 appendedMethodList = new ListBuffer<>();
242 dedupedLambdas = new HashMap<>();
243 deserializeCases = new HashMap<>();
244 MethodType type = new MethodType(List.of(syms.serializedLambdaType), syms.objectType,
245 List.nil(), syms.methodClass);
246 deserMethodSym = makePrivateSyntheticMethod(STATIC, names.deserializeLambda, type, clazz.sym);
247 deserParamSym = new VarSymbol(FINAL, names.fromString("lambda"),
248 syms.serializedLambdaType, deserMethodSym);
249 }
250
251 private void addMethod(JCTree decl) {
252 appendedMethodList = appendedMethodList.prepend(decl);
253 }
254 }
255
256 // <editor-fold defaultstate="collapsed" desc="translate methods">
257 @Override
258 public <T extends JCTree> T translate(T tree) {
259 TranslationContext<?> newContext = contextMap.get(tree);
260 return translate(tree, newContext != null ? newContext : context);
261 }
262
263 <T extends JCTree> T translate(T tree, TranslationContext<?> newContext) {
264 TranslationContext<?> prevContext = context;
265 try {
266 context = newContext;
267 return super.translate(tree);
268 }
269 finally {
270 context = prevContext;
271 }
272 }
273
274 <T extends JCTree> List<T> translate(List<T> trees, TranslationContext<?> newContext) {
275 ListBuffer<T> buf = new ListBuffer<>();
276 for (T tree : trees) {
277 buf.append(translate(tree, newContext));
278 }
279 return buf.toList();
280 }
281
282 public JCTree translateTopLevelClass(Env<AttrContext> env, JCTree cdef, TreeMaker make) {
283 this.make = make;
284 this.attrEnv = env;
285 this.context = null;
286 this.contextMap = new HashMap<>();
287 return translate(cdef);
288 }
289 // </editor-fold>
290
291 // <editor-fold defaultstate="collapsed" desc="visitor methods">
292 /**
293 * Visit a class.
294 * Maintain the translatedMethodList across nested classes.
295 * Append the translatedMethodList to the class after it is translated.
296 * @param tree
297 */
298 @Override
299 public void visitClassDef(JCClassDecl tree) {
300 if (tree.sym.owner.kind == PCK) {
301 //analyze class
302 tree = analyzer.analyzeAndPreprocessClass(tree);
303 }
304 KlassInfo prevKlassInfo = kInfo;
305 try {
306 kInfo = new KlassInfo(tree);
307 super.visitClassDef(tree);
308 if (!kInfo.deserializeCases.isEmpty()) {
309 int prevPos = make.pos;
310 try {
311 make.at(tree);
312 kInfo.addMethod(makeDeserializeMethod(tree.sym));
313 } finally {
314 make.at(prevPos);
315 }
316 }
317 //add all translated instance methods here
318 List<JCTree> newMethods = kInfo.appendedMethodList.toList();
319 tree.defs = tree.defs.appendList(newMethods);
320 for (JCTree lambda : newMethods) {
321 tree.sym.members().enter(((JCMethodDecl)lambda).sym);
322 }
323 result = tree;
324 } finally {
325 kInfo = prevKlassInfo;
326 }
327 }
328
329 /**
330 * Translate a lambda into a method to be inserted into the class.
331 * Then replace the lambda site with an invokedynamic call of to lambda
332 * meta-factory, which will use the lambda method.
333 * @param tree
334 */
335 @Override
336 public void visitLambda(JCLambda tree) {
337 LambdaTranslationContext localContext = (LambdaTranslationContext)context;
338 MethodSymbol sym = localContext.translatedSym;
339 MethodType lambdaType = (MethodType) sym.type;
340
341 { /* Type annotation management: Based on where the lambda features, type annotations that
342 are interior to it, may at this point be attached to the enclosing method, or the first
343 constructor in the class, or in the enclosing class symbol or in the field whose
344 initializer is the lambda. In any event, gather up the annotations that belong to the
345 lambda and attach it to the implementation method.
346 */
347
348 Symbol owner = localContext.owner;
349 apportionTypeAnnotations(tree,
350 owner::getRawTypeAttributes,
351 owner::setTypeAttributes,
352 sym::setTypeAttributes);
353
354
355 boolean init;
356 if ((init = (owner.name == names.init)) || owner.name == names.clinit) {
357 owner = owner.owner;
358 apportionTypeAnnotations(tree,
359 init ? owner::getInitTypeAttributes : owner::getClassInitTypeAttributes,
360 init ? owner::setInitTypeAttributes : owner::setClassInitTypeAttributes,
361 sym::appendUniqueTypeAttributes);
362 }
363 if (localContext.self != null && localContext.self.getKind() == ElementKind.FIELD) {
364 owner = localContext.self;
365 apportionTypeAnnotations(tree,
366 owner::getRawTypeAttributes,
367 owner::setTypeAttributes,
368 sym::appendUniqueTypeAttributes);
369 }
370 }
371
372 //create the method declaration hoisting the lambda body
373 JCMethodDecl lambdaDecl = make.MethodDef(make.Modifiers(sym.flags_field),
374 sym.name,
375 make.QualIdent(lambdaType.getReturnType().tsym),
376 List.nil(),
377 localContext.syntheticParams,
378 lambdaType.getThrownTypes() == null ?
379 List.nil() :
380 make.Types(lambdaType.getThrownTypes()),
381 null,
382 null);
383 lambdaDecl.sym = sym;
384 lambdaDecl.type = lambdaType;
385
386 //translate lambda body
387 //As the lambda body is translated, all references to lambda locals,
388 //captured variables, enclosing members are adjusted accordingly
389 //to refer to the static method parameters (rather than i.e. accessing
390 //captured members directly).
391 lambdaDecl.body = translate(makeLambdaBody(tree, lambdaDecl));
392
393 boolean dedupe = false;
394 if (deduplicateLambdas && !debugLinesOrVars && !localContext.isSerializable()) {
395 DedupedLambda dedupedLambda = new DedupedLambda(lambdaDecl.sym, lambdaDecl.body);
396 DedupedLambda existing = kInfo.dedupedLambdas.putIfAbsent(dedupedLambda, dedupedLambda);
397 if (existing != null) {
398 sym = existing.symbol;
399 dedupe = true;
400 if (verboseDeduplication) log.note(tree, Notes.VerboseL2mDeduplicate(sym));
401 }
402 }
403 if (!dedupe) {
404 //Add the method to the list of methods to be added to this class.
405 kInfo.addMethod(lambdaDecl);
406 }
407
408 //now that we have generated a method for the lambda expression,
409 //we can translate the lambda into a method reference pointing to the newly
410 //created method.
411 //
412 //Note that we need to adjust the method handle so that it will match the
413 //signature of the SAM descriptor - this means that the method reference
414 //should be added the following synthetic arguments:
415 //
416 // * the "this" argument if it is an instance method
417 // * enclosing locals captured by the lambda expression
418
419 ListBuffer<JCExpression> syntheticInits = new ListBuffer<>();
420
421 if (localContext.methodReferenceReceiver != null) {
422 syntheticInits.append(localContext.methodReferenceReceiver);
423 } else if (!sym.isStatic()) {
424 syntheticInits.append(makeThis(
425 sym.owner.enclClass().asType(),
426 localContext.owner.enclClass()));
427 }
428
429 //add captured locals
430 for (Symbol fv : localContext.getSymbolMap(CAPTURED_VAR).keySet()) {
431 if (fv != localContext.self) {
432 JCExpression captured_local = make.Ident(fv).setType(fv.type);
433 syntheticInits.append(captured_local);
434 }
435 }
436 // add captured outer this instances (used only when `this' capture itself is illegal)
437 for (Symbol fv : localContext.getSymbolMap(CAPTURED_OUTER_THIS).keySet()) {
438 JCExpression captured_local = make.QualThis(fv.type);
439 syntheticInits.append(captured_local);
440 }
441
442 //then, determine the arguments to the indy call
443 List<JCExpression> indy_args = translate(syntheticInits.toList(), localContext.prev);
444
445 //convert to an invokedynamic call
446 result = makeMetafactoryIndyCall(context, sym.asHandle(), indy_args);
447 }
448
449 // where
450 // Reassign type annotations from the source that should really belong to the lambda
451 private void apportionTypeAnnotations(JCLambda tree,
452 Supplier<List<Attribute.TypeCompound>> source,
453 Consumer<List<Attribute.TypeCompound>> owner,
454 Consumer<List<Attribute.TypeCompound>> lambda) {
455
456 ListBuffer<Attribute.TypeCompound> ownerTypeAnnos = new ListBuffer<>();
457 ListBuffer<Attribute.TypeCompound> lambdaTypeAnnos = new ListBuffer<>();
458
459 for (Attribute.TypeCompound tc : source.get()) {
460 if (tc.position.onLambda == tree) {
461 lambdaTypeAnnos.append(tc);
462 } else {
463 ownerTypeAnnos.append(tc);
464 }
465 }
466 if (lambdaTypeAnnos.nonEmpty()) {
467 owner.accept(ownerTypeAnnos.toList());
468 lambda.accept(lambdaTypeAnnos.toList());
469 }
470 }
471
472 private JCIdent makeThis(Type type, Symbol owner) {
473 VarSymbol _this = new VarSymbol(PARAMETER | FINAL | SYNTHETIC,
474 names._this,
475 type,
476 owner);
477 return make.Ident(_this);
478 }
479
480 /**
481 * Translate a method reference into an invokedynamic call to the
482 * meta-factory.
483 * @param tree
484 */
485 @Override
486 public void visitReference(JCMemberReference tree) {
487 ReferenceTranslationContext localContext = (ReferenceTranslationContext)context;
488
489 //first determine the method symbol to be used to generate the sam instance
490 //this is either the method reference symbol, or the bridged reference symbol
491 MethodSymbol refSym = (MethodSymbol)tree.sym;
492
493 //the qualifying expression is treated as a special captured arg
494 JCExpression init;
495 switch(tree.kind) {
496
497 case IMPLICIT_INNER: /** Inner :: new */
498 case SUPER: /** super :: instMethod */
499 init = makeThis(
500 localContext.owner.enclClass().asType(),
501 localContext.owner.enclClass());
502 break;
503
504 case BOUND: /** Expr :: instMethod */
505 init = transTypes.coerce(attrEnv, tree.getQualifierExpression(),
506 types.erasure(tree.sym.owner.type));
507 init = attr.makeNullCheck(init);
508 break;
509
510 case UNBOUND: /** Type :: instMethod */
511 case STATIC: /** Type :: staticMethod */
512 case TOPLEVEL: /** Top level :: new */
513 case ARRAY_CTOR: /** ArrayType :: new */
514 init = null;
515 break;
516
517 default:
518 throw new InternalError("Should not have an invalid kind");
519 }
520
521 List<JCExpression> indy_args = init==null? List.nil() : translate(List.of(init), localContext.prev);
522
523
524 //build a sam instance using an indy call to the meta-factory
525 result = makeMetafactoryIndyCall(localContext, refSym.asHandle(), indy_args);
526 }
527
528 /**
529 * Translate identifiers within a lambda to the mapped identifier
530 * @param tree
531 */
532 @Override
533 public void visitIdent(JCIdent tree) {
534 if (context == null || !analyzer.lambdaIdentSymbolFilter(tree.sym)) {
535 super.visitIdent(tree);
536 } else {
537 int prevPos = make.pos;
538 try {
539 make.at(tree);
540
541 LambdaTranslationContext lambdaContext = (LambdaTranslationContext) context;
542 JCTree ltree = lambdaContext.translate(tree);
543 if (ltree != null) {
544 result = ltree;
545 } else {
546 //access to untranslated symbols (i.e. compile-time constants,
547 //members defined inside the lambda body, etc.) )
548 super.visitIdent(tree);
549 }
550 } finally {
551 make.at(prevPos);
552 }
553 }
554 }
555
556 /**
557 * Translate qualified `this' references within a lambda to the mapped identifier
558 * @param tree
559 */
560 @Override
561 public void visitSelect(JCFieldAccess tree) {
562 if (context == null || !analyzer.lambdaFieldAccessFilter(tree)) {
563 super.visitSelect(tree);
564 } else {
565 int prevPos = make.pos;
566 try {
567 make.at(tree);
568
569 LambdaTranslationContext lambdaContext = (LambdaTranslationContext) context;
570 JCTree ltree = lambdaContext.translate(tree);
571 if (ltree != null) {
572 result = ltree;
573 } else {
574 super.visitSelect(tree);
575 }
576 } finally {
577 make.at(prevPos);
578 }
579 }
580 }
581
582 /**
583 * Translate instance creation expressions with implicit enclosing instances
584 * @param tree
585 */
586 @Override
587 public void visitNewClass(JCNewClass tree) {
588 if (context == null || !analyzer.lambdaNewClassFilter(context, tree)) {
589 super.visitNewClass(tree);
590 } else {
591 int prevPos = make.pos;
592 try {
593 make.at(tree);
594
595 LambdaTranslationContext lambdaContext = (LambdaTranslationContext) context;
596 tree = lambdaContext.translate(tree);
597 super.visitNewClass(tree);
598 } finally {
599 make.at(prevPos);
600 }
601 }
602 }
603
604 @Override
605 public void visitVarDef(JCVariableDecl tree) {
606 LambdaTranslationContext lambdaContext = (LambdaTranslationContext)context;
607 if (context != null && lambdaContext.getSymbolMap(LOCAL_VAR).containsKey(tree.sym)) {
608 tree.init = translate(tree.init);
609 tree.sym = (VarSymbol) lambdaContext.getSymbolMap(LOCAL_VAR).get(tree.sym);
610 result = tree;
611 } else {
612 super.visitVarDef(tree);
613 }
614 }
615
616 // </editor-fold>
617
618 // <editor-fold defaultstate="collapsed" desc="Translation helper methods">
619
620 private JCBlock makeLambdaBody(JCLambda tree, JCMethodDecl lambdaMethodDecl) {
621 return tree.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
622 makeLambdaExpressionBody((JCExpression)tree.body, lambdaMethodDecl) :
623 makeLambdaStatementBody((JCBlock)tree.body, lambdaMethodDecl, tree.canCompleteNormally);
624 }
625
626 private JCBlock makeLambdaExpressionBody(JCExpression expr, JCMethodDecl lambdaMethodDecl) {
627 Type restype = lambdaMethodDecl.type.getReturnType();
628 boolean isLambda_void = expr.type.hasTag(VOID);
629 boolean isTarget_void = restype.hasTag(VOID);
630 boolean isTarget_Void = types.isSameType(restype, types.boxedClass(syms.voidType).type);
631 int prevPos = make.pos;
632 try {
633 if (isTarget_void) {
634 //target is void:
635 // BODY;
636 JCStatement stat = make.at(expr).Exec(expr);
637 return make.Block(0, List.of(stat));
638 } else if (isLambda_void && isTarget_Void) {
639 //void to Void conversion:
640 // BODY; return null;
641 ListBuffer<JCStatement> stats = new ListBuffer<>();
642 stats.append(make.at(expr).Exec(expr));
643 stats.append(make.Return(make.Literal(BOT, null).setType(syms.botType)));
644 return make.Block(0, stats.toList());
645 } else {
646 //non-void to non-void conversion:
647 // return BODY;
648 return make.at(expr).Block(0, List.of(make.Return(expr)));
649 }
650 } finally {
651 make.at(prevPos);
652 }
653 }
654
655 private JCBlock makeLambdaStatementBody(JCBlock block, final JCMethodDecl lambdaMethodDecl, boolean completeNormally) {
656 final Type restype = lambdaMethodDecl.type.getReturnType();
657 final boolean isTarget_void = restype.hasTag(VOID);
658 boolean isTarget_Void = types.isSameType(restype, types.boxedClass(syms.voidType).type);
659
660 class LambdaBodyTranslator extends TreeTranslator {
661
662 @Override
663 public void visitClassDef(JCClassDecl tree) {
664 //do NOT recurse on any inner classes
665 result = tree;
666 }
667
668 @Override
669 public void visitLambda(JCLambda tree) {
670 //do NOT recurse on any nested lambdas
671 result = tree;
672 }
673
674 @Override
675 public void visitReturn(JCReturn tree) {
676 boolean isLambda_void = tree.expr == null;
677 if (isTarget_void && !isLambda_void) {
678 //Void to void conversion:
679 // { TYPE $loc = RET-EXPR; return; }
680 VarSymbol loc = makeSyntheticVar(0, names.fromString("$loc"), tree.expr.type, lambdaMethodDecl.sym);
681 JCVariableDecl varDef = make.VarDef(loc, tree.expr);
682 result = make.Block(0, List.of(varDef, make.Return(null)));
683 } else {
684 result = tree;
685 }
686
687 }
688 }
689
690 JCBlock trans_block = new LambdaBodyTranslator().translate(block);
691 if (completeNormally && isTarget_Void) {
692 //there's no return statement and the lambda (possibly inferred)
693 //return type is java.lang.Void; emit a synthetic return statement
694 trans_block.stats = trans_block.stats.append(make.Return(make.Literal(BOT, null).setType(syms.botType)));
695 }
696 return trans_block;
697 }
698
699 private JCMethodDecl makeDeserializeMethod(Symbol kSym) {
700 ListBuffer<JCCase> cases = new ListBuffer<>();
701 ListBuffer<JCBreak> breaks = new ListBuffer<>();
702 for (Map.Entry<String, ListBuffer<JCStatement>> entry : kInfo.deserializeCases.entrySet()) {
703 JCBreak br = make.Break(null);
704 breaks.add(br);
705 List<JCStatement> stmts = entry.getValue().append(br).toList();
706 cases.add(make.Case(JCCase.STATEMENT, List.of(make.ConstantCaseLabel(make.Literal(entry.getKey()))), null, stmts, null));
707 }
708 JCSwitch sw = make.Switch(deserGetter("getImplMethodName", syms.stringType), cases.toList());
709 for (JCBreak br : breaks) {
710 br.target = sw;
711 }
712 JCBlock body = make.Block(0L, List.of(
713 sw,
714 make.Throw(makeNewClass(
715 syms.illegalArgumentExceptionType,
716 List.of(make.Literal("Invalid lambda deserialization"))))));
717 JCMethodDecl deser = make.MethodDef(make.Modifiers(kInfo.deserMethodSym.flags()),
718 names.deserializeLambda,
719 make.QualIdent(kInfo.deserMethodSym.getReturnType().tsym),
720 List.nil(),
721 List.of(make.VarDef(kInfo.deserParamSym, null)),
722 List.nil(),
723 body,
724 null);
725 deser.sym = kInfo.deserMethodSym;
726 deser.type = kInfo.deserMethodSym.type;
727 //System.err.printf("DESER: '%s'\n", deser);
728 return deser;
729 }
730
731 /** Make an attributed class instance creation expression.
732 * @param ctype The class type.
733 * @param args The constructor arguments.
734 * @param cons The constructor symbol
735 */
736 JCNewClass makeNewClass(Type ctype, List<JCExpression> args, Symbol cons) {
737 JCNewClass tree = make.NewClass(null,
738 null, make.QualIdent(ctype.tsym), args, null);
739 tree.constructor = cons;
740 tree.type = ctype;
741 return tree;
742 }
743
744 /** Make an attributed class instance creation expression.
745 * @param ctype The class type.
746 * @param args The constructor arguments.
747 */
748 JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
749 return makeNewClass(ctype, args,
750 rs.resolveConstructor(null, attrEnv, ctype, TreeInfo.types(args), List.nil()));
751 }
752
753 private void addDeserializationCase(MethodHandleSymbol refSym, Type targetType, MethodSymbol samSym,
754 DiagnosticPosition pos, List<LoadableConstant> staticArgs, MethodType indyType) {
755 String functionalInterfaceClass = classSig(targetType);
756 String functionalInterfaceMethodName = samSym.getSimpleName().toString();
757 String functionalInterfaceMethodSignature = typeSig(types.erasure(samSym.type));
758 Symbol baseMethod = refSym.baseSymbol();
759 Symbol origMethod = baseMethod.baseSymbol();
760 if (baseMethod != origMethod && origMethod.owner == syms.objectType.tsym) {
761 //the implementation method is a java.lang.Object method transferred to an
762 //interface that does not declare it. Runtime will refer to this method as to
763 //a java.lang.Object method, so do the same:
764 refSym = ((MethodSymbol) origMethod).asHandle();
765 }
766 String implClass = classSig(types.erasure(refSym.owner.type));
767 String implMethodName = refSym.getQualifiedName().toString();
768 String implMethodSignature = typeSig(types.erasure(refSym.type));
769
770 JCExpression kindTest = eqTest(syms.intType, deserGetter("getImplMethodKind", syms.intType),
771 make.Literal(refSym.referenceKind()));
772 ListBuffer<JCExpression> serArgs = new ListBuffer<>();
773 int i = 0;
774 for (Type t : indyType.getParameterTypes()) {
775 List<JCExpression> indexAsArg = new ListBuffer<JCExpression>().append(make.Literal(i)).toList();
776 List<Type> argTypes = new ListBuffer<Type>().append(syms.intType).toList();
777 serArgs.add(make.TypeCast(types.erasure(t), deserGetter("getCapturedArg", syms.objectType, argTypes, indexAsArg)));
778 ++i;
779 }
780 JCStatement stmt = make.If(
781 deserTest(deserTest(deserTest(deserTest(deserTest(
782 kindTest,
783 "getFunctionalInterfaceClass", functionalInterfaceClass),
784 "getFunctionalInterfaceMethodName", functionalInterfaceMethodName),
785 "getFunctionalInterfaceMethodSignature", functionalInterfaceMethodSignature),
786 "getImplClass", implClass),
787 "getImplMethodSignature", implMethodSignature),
788 make.Return(makeIndyCall(
789 pos,
790 syms.lambdaMetafactory,
791 names.altMetafactory,
792 staticArgs, indyType, serArgs.toList(), samSym.name)),
793 null);
794 ListBuffer<JCStatement> stmts = kInfo.deserializeCases.get(implMethodName);
795 if (stmts == null) {
796 stmts = new ListBuffer<>();
797 kInfo.deserializeCases.put(implMethodName, stmts);
798 }
799 /****
800 System.err.printf("+++++++++++++++++\n");
801 System.err.printf("*functionalInterfaceClass: '%s'\n", functionalInterfaceClass);
802 System.err.printf("*functionalInterfaceMethodName: '%s'\n", functionalInterfaceMethodName);
803 System.err.printf("*functionalInterfaceMethodSignature: '%s'\n", functionalInterfaceMethodSignature);
804 System.err.printf("*implMethodKind: %d\n", implMethodKind);
805 System.err.printf("*implClass: '%s'\n", implClass);
806 System.err.printf("*implMethodName: '%s'\n", implMethodName);
807 System.err.printf("*implMethodSignature: '%s'\n", implMethodSignature);
808 ****/
809 stmts.append(stmt);
810 }
811
812 private JCExpression eqTest(Type argType, JCExpression arg1, JCExpression arg2) {
813 JCBinary testExpr = make.Binary(JCTree.Tag.EQ, arg1, arg2);
814 testExpr.operator = operators.resolveBinary(testExpr, JCTree.Tag.EQ, argType, argType);
815 testExpr.setType(syms.booleanType);
816 return testExpr;
817 }
818
819 private JCExpression deserTest(JCExpression prev, String func, String lit) {
820 MethodType eqmt = new MethodType(List.of(syms.objectType), syms.booleanType, List.nil(), syms.methodClass);
821 Symbol eqsym = rs.resolveQualifiedMethod(null, attrEnv, syms.objectType, names.equals, List.of(syms.objectType), List.nil());
822 JCMethodInvocation eqtest = make.Apply(
823 List.nil(),
824 make.Select(deserGetter(func, syms.stringType), eqsym).setType(eqmt),
825 List.of(make.Literal(lit)));
826 eqtest.setType(syms.booleanType);
827 JCBinary compound = make.Binary(JCTree.Tag.AND, prev, eqtest);
828 compound.operator = operators.resolveBinary(compound, JCTree.Tag.AND, syms.booleanType, syms.booleanType);
829 compound.setType(syms.booleanType);
830 return compound;
831 }
832
833 private JCExpression deserGetter(String func, Type type) {
834 return deserGetter(func, type, List.nil(), List.nil());
835 }
836
837 private JCExpression deserGetter(String func, Type type, List<Type> argTypes, List<JCExpression> args) {
838 MethodType getmt = new MethodType(argTypes, type, List.nil(), syms.methodClass);
839 Symbol getsym = rs.resolveQualifiedMethod(null, attrEnv, syms.serializedLambdaType, names.fromString(func), argTypes, List.nil());
840 return make.Apply(
841 List.nil(),
842 make.Select(make.Ident(kInfo.deserParamSym).setType(syms.serializedLambdaType), getsym).setType(getmt),
843 args).setType(type);
844 }
845
846 /**
847 * Create new synthetic method with given flags, name, type, owner
848 */
849 private MethodSymbol makePrivateSyntheticMethod(long flags, Name name, Type type, Symbol owner) {
850 return new MethodSymbol(flags | SYNTHETIC | PRIVATE, name, type, owner);
851 }
852
853 /**
854 * Create new synthetic variable with given flags, name, type, owner
855 */
856 private VarSymbol makeSyntheticVar(long flags, Name name, Type type, Symbol owner) {
857 return new VarSymbol(flags | SYNTHETIC, name, type, owner);
858 }
859
860 /**
861 * Set varargsElement field on a given tree (must be either a new class tree
862 * or a method call tree)
863 */
864 private void setVarargsIfNeeded(JCTree tree, Type varargsElement) {
865 if (varargsElement != null) {
866 switch (tree.getTag()) {
867 case APPLY: ((JCMethodInvocation)tree).varargsElement = varargsElement; break;
868 case NEWCLASS: ((JCNewClass)tree).varargsElement = varargsElement; break;
869 case TYPECAST: setVarargsIfNeeded(((JCTypeCast) tree).expr, varargsElement); break;
870 default: throw new AssertionError();
871 }
872 }
873 }
874
875 /**
876 * Convert method/constructor arguments by inserting appropriate cast
877 * as required by type-erasure - this is needed when bridging a lambda/method
878 * reference, as the bridged signature might require downcast to be compatible
879 * with the generated signature.
880 */
881 private List<JCExpression> convertArgs(Symbol meth, List<JCExpression> args, Type varargsElement) {
882 Assert.check(meth.kind == MTH);
883 List<Type> formals = types.erasure(meth.type).getParameterTypes();
884 if (varargsElement != null) {
885 Assert.check((meth.flags() & VARARGS) != 0);
886 }
887 return transTypes.translateArgs(args, formals, varargsElement, attrEnv);
888 }
889
890 // </editor-fold>
891
892 /**
893 * Converts a method reference which cannot be used directly into a lambda
894 */
895 private class MemberReferenceToLambda {
896
897 private final JCMemberReference tree;
898 private final ReferenceTranslationContext localContext;
899 private final Symbol owner;
900 private final ListBuffer<JCExpression> args = new ListBuffer<>();
901 private final ListBuffer<JCVariableDecl> params = new ListBuffer<>();
902
903 private JCExpression receiverExpression = null;
904
905 MemberReferenceToLambda(JCMemberReference tree, ReferenceTranslationContext localContext, Symbol owner) {
906 this.tree = tree;
907 this.localContext = localContext;
908 this.owner = owner;
909 }
910
911 JCLambda lambda() {
912 int prevPos = make.pos;
913 try {
914 make.at(tree);
915
916 //body generation - this can be either a method call or a
917 //new instance creation expression, depending on the member reference kind
918 VarSymbol rcvr = addParametersReturnReceiver();
919 JCExpression expr = (tree.getMode() == ReferenceMode.INVOKE)
920 ? expressionInvoke(rcvr)
921 : expressionNew();
922
923 JCLambda slam = make.Lambda(params.toList(), expr);
924 slam.target = tree.target;
925 slam.type = tree.type;
926 slam.pos = tree.pos;
927 return slam;
928 } finally {
929 make.at(prevPos);
930 }
931 }
932
933 /**
934 * Generate the parameter list for the converted member reference.
935 *
936 * @return The receiver variable symbol, if any
937 */
938 VarSymbol addParametersReturnReceiver() {
939 Type samDesc = localContext.bridgedRefSig();
940 List<Type> samPTypes = samDesc.getParameterTypes();
941 List<Type> descPTypes = tree.getDescriptorType(types).getParameterTypes();
942
943 // Determine the receiver, if any
944 VarSymbol rcvr;
945 switch (tree.kind) {
946 case BOUND:
947 // The receiver is explicit in the method reference
948 rcvr = addParameter("rec$", tree.getQualifierExpression().type, false);
949 receiverExpression = attr.makeNullCheck(tree.getQualifierExpression());
950 break;
951 case UNBOUND:
952 // The receiver is the first parameter, extract it and
953 // adjust the SAM and unerased type lists accordingly
954 rcvr = addParameter("rec$", samDesc.getParameterTypes().head, false);
955 samPTypes = samPTypes.tail;
956 descPTypes = descPTypes.tail;
957 break;
958 default:
959 rcvr = null;
960 break;
961 }
962 List<Type> implPTypes = tree.sym.type.getParameterTypes();
963 int implSize = implPTypes.size();
964 int samSize = samPTypes.size();
965 // Last parameter to copy from referenced method, exclude final var args
966 int last = localContext.needsVarArgsConversion() ? implSize - 1 : implSize;
967
968 // Failsafe -- assure match-up
969 boolean checkForIntersection = tree.varargsElement != null || implSize == descPTypes.size();
970
971 // Use parameter types of the implementation method unless the unerased
972 // SAM parameter type is an intersection type, in that case use the
973 // erased SAM parameter type so that the supertype relationship
974 // the implementation method parameters is not obscured.
975 // Note: in this loop, the lists implPTypes, samPTypes, and descPTypes
976 // are used as pointers to the current parameter type information
977 // and are thus not usable afterwards.
978 for (int i = 0; implPTypes.nonEmpty() && i < last; ++i) {
979 // By default use the implementation method parameter type
980 Type parmType = implPTypes.head;
981 if (checkForIntersection) {
982 if (descPTypes.head.getKind() == TypeKind.INTERSECTION) {
983 parmType = samPTypes.head;
984 }
985 // If the unerased parameter type is a type variable whose
986 // bound is an intersection (eg. <T extends A & B>) then
987 // use the SAM parameter type
988 if (descPTypes.head.getKind() == TypeKind.TYPEVAR) {
989 TypeVar tv = (TypeVar) descPTypes.head;
990 if (tv.getUpperBound().getKind() == TypeKind.INTERSECTION) {
991 parmType = samPTypes.head;
992 }
993 }
994 }
995 addParameter("x$" + i, parmType, true);
996
997 // Advance to the next parameter
998 implPTypes = implPTypes.tail;
999 samPTypes = samPTypes.tail;
1000 descPTypes = descPTypes.tail;
1001 }
1002 // Flatten out the var args
1003 for (int i = last; i < samSize; ++i) {
1004 addParameter("xva$" + i, tree.varargsElement, true);
1005 }
1006
1007 return rcvr;
1008 }
1009
1010 JCExpression getReceiverExpression() {
1011 return receiverExpression;
1012 }
1013
1014 private JCExpression makeReceiver(VarSymbol rcvr) {
1015 if (rcvr == null) return null;
1016 JCExpression rcvrExpr = make.Ident(rcvr);
1017 boolean protAccess =
1018 isProtectedInSuperClassOfEnclosingClassInOtherPackage(tree.sym, owner);
1019 Type rcvrType = tree.ownerAccessible && !protAccess ? tree.sym.enclClass().type
1020 : tree.expr.type;
1021 if (rcvrType == syms.arrayClass.type) {
1022 // Map the receiver type to the actually type, not just "array"
1023 rcvrType = tree.getQualifierExpression().type;
1024 }
1025 if (!rcvr.type.tsym.isSubClass(rcvrType.tsym, types)) {
1026 rcvrExpr = make.TypeCast(make.Type(rcvrType), rcvrExpr).setType(rcvrType);
1027 }
1028 return rcvrExpr;
1029 }
1030
1031 /**
1032 * determine the receiver of the method call - the receiver can
1033 * be a type qualifier, the synthetic receiver parameter or 'super'.
1034 */
1035 private JCExpression expressionInvoke(VarSymbol rcvr) {
1036 JCExpression qualifier =
1037 (rcvr != null) ?
1038 makeReceiver(rcvr) :
1039 tree.getQualifierExpression();
1040
1041 //create the qualifier expression
1042 JCFieldAccess select = make.Select(qualifier, tree.sym.name);
1043 select.sym = tree.sym;
1044 select.type = tree.sym.erasure(types);
1045
1046 //create the method call expression
1047 JCExpression apply = make.Apply(List.nil(), select,
1048 convertArgs(tree.sym, args.toList(), tree.varargsElement)).
1049 setType(tree.sym.erasure(types).getReturnType());
1050
1051 apply = transTypes.coerce(attrEnv, apply,
1052 types.erasure(localContext.tree.referentType.getReturnType()));
1053
1054 setVarargsIfNeeded(apply, tree.varargsElement);
1055 return apply;
1056 }
1057
1058 /**
1059 * Lambda body to use for a 'new'.
1060 */
1061 private JCExpression expressionNew() {
1062 if (tree.kind == ReferenceKind.ARRAY_CTOR) {
1063 //create the array creation expression
1064 JCNewArray newArr = make.NewArray(
1065 make.Type(types.elemtype(tree.getQualifierExpression().type)),
1066 List.of(make.Ident(params.first())),
1067 null);
1068 newArr.type = tree.getQualifierExpression().type;
1069 return newArr;
1070 } else {
1071 //create the instance creation expression
1072 //note that method reference syntax does not allow an explicit
1073 //enclosing class (so the enclosing class is null)
1074 // but this may need to be patched up later with the proxy for the outer this
1075 JCNewClass newClass = make.NewClass(null,
1076 List.nil(),
1077 make.Type(tree.getQualifierExpression().type),
1078 convertArgs(tree.sym, args.toList(), tree.varargsElement),
1079 null);
1080 newClass.constructor = tree.sym;
1081 newClass.constructorType = tree.sym.erasure(types);
1082 newClass.type = tree.getQualifierExpression().type;
1083 setVarargsIfNeeded(newClass, tree.varargsElement);
1084 return newClass;
1085 }
1086 }
1087
1088 private VarSymbol addParameter(String name, Type p, boolean genArg) {
1089 VarSymbol vsym = new VarSymbol(PARAMETER | SYNTHETIC, names.fromString(name), p, owner);
1090 vsym.pos = tree.pos;
1091 params.append(make.VarDef(vsym, null));
1092 if (genArg) {
1093 args.append(make.Ident(vsym));
1094 }
1095 return vsym;
1096 }
1097 }
1098
1099 private MethodType typeToMethodType(Type mt) {
1100 Type type = types.erasure(mt);
1101 return new MethodType(type.getParameterTypes(),
1102 type.getReturnType(),
1103 type.getThrownTypes(),
1104 syms.methodClass);
1105 }
1106
1107 /**
1108 * Generate an indy method call to the meta factory
1109 */
1110 private JCExpression makeMetafactoryIndyCall(TranslationContext<?> context,
1111 MethodHandleSymbol refSym, List<JCExpression> indy_args) {
1112 JCFunctionalExpression tree = context.tree;
1113 //determine the static bsm args
1114 MethodSymbol samSym = (MethodSymbol) types.findDescriptorSymbol(tree.target.tsym);
1115 List<LoadableConstant> staticArgs = List.of(
1116 typeToMethodType(samSym.type),
1117 refSym.asHandle(),
1118 typeToMethodType(tree.getDescriptorType(types)));
1119
1120 //computed indy arg types
1121 ListBuffer<Type> indy_args_types = new ListBuffer<>();
1122 for (JCExpression arg : indy_args) {
1123 indy_args_types.append(arg.type);
1124 }
1125
1126 //finally, compute the type of the indy call
1127 MethodType indyType = new MethodType(indy_args_types.toList(),
1128 tree.type,
1129 List.nil(),
1130 syms.methodClass);
1131
1132 Name metafactoryName = context.needsAltMetafactory() ?
1133 names.altMetafactory : names.metafactory;
1134
1135 if (context.needsAltMetafactory()) {
1136 ListBuffer<Type> markers = new ListBuffer<>();
1137 List<Type> targets = tree.target.isIntersection() ?
1138 types.directSupertypes(tree.target) :
1139 List.nil();
1140 for (Type t : targets) {
1141 t = types.erasure(t);
1142 if (t.tsym != syms.serializableType.tsym &&
1143 t.tsym != tree.type.tsym &&
1144 t.tsym != syms.objectType.tsym) {
1145 markers.append(t);
1146 }
1147 }
1148 int flags = context.isSerializable() ? FLAG_SERIALIZABLE : 0;
1149 boolean hasMarkers = markers.nonEmpty();
1150 boolean hasBridges = context.bridges.nonEmpty();
1151 if (hasMarkers) {
1152 flags |= FLAG_MARKERS;
1153 }
1154 if (hasBridges) {
1155 flags |= FLAG_BRIDGES;
1156 }
1157 staticArgs = staticArgs.append(LoadableConstant.Int(flags));
1158 if (hasMarkers) {
1159 staticArgs = staticArgs.append(LoadableConstant.Int(markers.length()));
1160 staticArgs = staticArgs.appendList(List.convert(LoadableConstant.class, markers.toList()));
1161 }
1162 if (hasBridges) {
1163 staticArgs = staticArgs.append(LoadableConstant.Int(context.bridges.length() - 1));
1164 for (Symbol s : context.bridges) {
1165 Type s_erasure = s.erasure(types);
1166 if (!types.isSameType(s_erasure, samSym.erasure(types))) {
1167 staticArgs = staticArgs.append(((MethodType)s.erasure(types)));
1168 }
1169 }
1170 }
1171 if (context.isSerializable()) {
1172 int prevPos = make.pos;
1173 try {
1174 make.at(kInfo.clazz);
1175 addDeserializationCase(refSym, tree.type, samSym,
1176 tree, staticArgs, indyType);
1177 } finally {
1178 make.at(prevPos);
1179 }
1180 }
1181 }
1182
1183 return makeIndyCall(tree, syms.lambdaMetafactory, metafactoryName, staticArgs, indyType, indy_args, samSym.name);
1184 }
1185
1186 /**
1187 * Generate an indy method call with given name, type and static bootstrap
1188 * arguments types
1189 */
1190 private JCExpression makeIndyCall(DiagnosticPosition pos, Type site, Name bsmName,
1191 List<LoadableConstant> staticArgs, MethodType indyType, List<JCExpression> indyArgs,
1192 Name methName) {
1193 int prevPos = make.pos;
1194 try {
1195 make.at(pos);
1196 List<Type> bsm_staticArgs = List.of(syms.methodHandleLookupType,
1197 syms.stringType,
1198 syms.methodTypeType).appendList(staticArgs.map(types::constantType));
1199
1200 MethodSymbol bsm = rs.resolveInternalMethod(pos, attrEnv, site,
1201 bsmName, bsm_staticArgs, List.nil());
1202
1203 DynamicMethodSymbol dynSym =
1204 new DynamicMethodSymbol(methName,
1205 syms.noSymbol,
1206 bsm.asHandle(),
1207 indyType,
1208 staticArgs.toArray(new LoadableConstant[staticArgs.length()]));
1209 JCFieldAccess qualifier = make.Select(make.QualIdent(site.tsym), bsmName);
1210 DynamicMethodSymbol existing = kInfo.dynMethSyms.putIfAbsent(
1211 dynSym.poolKey(types), dynSym);
1212 qualifier.sym = existing != null ? existing : dynSym;
1213 qualifier.type = indyType.getReturnType();
1214
1215 JCMethodInvocation proxyCall = make.Apply(List.nil(), qualifier, indyArgs);
1216 proxyCall.type = indyType.getReturnType();
1217 return proxyCall;
1218 } finally {
1219 make.at(prevPos);
1220 }
1221 }
1222
1223 // <editor-fold defaultstate="collapsed" desc="Lambda/reference analyzer">
1224 /**
1225 * This visitor collects information about translation of a lambda expression.
1226 * More specifically, it keeps track of the enclosing contexts and captured locals
1227 * accessed by the lambda being translated (as well as other useful info).
1228 * It also translates away problems for LambdaToMethod.
1229 */
1230 class LambdaAnalyzerPreprocessor extends TreeTranslator {
1231
1232 /** the frame stack - used to reconstruct translation info about enclosing scopes */
1233 private List<Frame> frameStack;
1234
1235 /**
1236 * keep the count of lambda expression (used to generate unambiguous
1237 * names)
1238 */
1239 private int lambdaCount = 0;
1240
1241 /**
1242 * List of types undergoing construction via explicit constructor chaining.
1243 */
1244 private List<ClassSymbol> typesUnderConstruction;
1245
1246 /**
1247 * keep the count of lambda expression defined in given context (used to
1248 * generate unambiguous names for serializable lambdas)
1249 */
1250 private class SyntheticMethodNameCounter {
1251 private Map<String, Integer> map = new HashMap<>();
1252 int getIndex(StringBuilder buf) {
1253 String temp = buf.toString();
1254 Integer count = map.get(temp);
1255 if (count == null) {
1256 count = 0;
1257 }
1258 ++count;
1259 map.put(temp, count);
1260 return count;
1261 }
1262 }
1263 private SyntheticMethodNameCounter syntheticMethodNameCounts =
1264 new SyntheticMethodNameCounter();
1265
1266 private Map<Symbol, JCClassDecl> localClassDefs;
1267
1268 /**
1269 * maps for fake clinit symbols to be used as owners of lambda occurring in
1270 * a static var init context
1271 */
1272 private Map<ClassSymbol, Symbol> clinits = new HashMap<>();
1273
1274 private JCClassDecl analyzeAndPreprocessClass(JCClassDecl tree) {
1275 frameStack = List.nil();
1276 typesUnderConstruction = List.nil();
1277 localClassDefs = new HashMap<>();
1278 return translate(tree);
1279 }
1280
1281 @Override
1282 public void visitApply(JCMethodInvocation tree) {
1283 List<ClassSymbol> previousNascentTypes = typesUnderConstruction;
1284 try {
1285 Name methName = TreeInfo.name(tree.meth);
1286 if (methName == names._this || methName == names._super) {
1287 typesUnderConstruction = typesUnderConstruction.prepend(currentClass());
1288 }
1289 super.visitApply(tree);
1290 } finally {
1291 typesUnderConstruction = previousNascentTypes;
1292 }
1293 }
1294 // where
1295 private ClassSymbol currentClass() {
1296 for (Frame frame : frameStack) {
1297 if (frame.tree.hasTag(JCTree.Tag.CLASSDEF)) {
1298 JCClassDecl cdef = (JCClassDecl) frame.tree;
1299 return cdef.sym;
1300 }
1301 }
1302 return null;
1303 }
1304
1305 @Override
1306 public void visitBlock(JCBlock tree) {
1307 List<Frame> prevStack = frameStack;
1308 try {
1309 if (frameStack.nonEmpty() && frameStack.head.tree.hasTag(CLASSDEF)) {
1310 frameStack = frameStack.prepend(new Frame(tree));
1311 }
1312 super.visitBlock(tree);
1313 }
1314 finally {
1315 frameStack = prevStack;
1316 }
1317 }
1318
1319 @Override
1320 public void visitClassDef(JCClassDecl tree) {
1321 List<Frame> prevStack = frameStack;
1322 int prevLambdaCount = lambdaCount;
1323 SyntheticMethodNameCounter prevSyntheticMethodNameCounts =
1324 syntheticMethodNameCounts;
1325 Map<ClassSymbol, Symbol> prevClinits = clinits;
1326 DiagnosticSource prevSource = log.currentSource();
1327 try {
1328 log.useSource(tree.sym.sourcefile);
1329 lambdaCount = 0;
1330 syntheticMethodNameCounts = new SyntheticMethodNameCounter();
1331 prevClinits = new HashMap<>();
1332 if (tree.sym.owner.kind == MTH) {
1333 localClassDefs.put(tree.sym, tree);
1334 }
1335 if (directlyEnclosingLambda() != null) {
1336 tree.sym.owner = owner();
1337 if (tree.sym.hasOuterInstance()) {
1338 //if a class is defined within a lambda, the lambda must capture
1339 //its enclosing instance (if any)
1340 TranslationContext<?> localContext = context();
1341 final TypeSymbol outerInstanceSymbol = tree.sym.type.getEnclosingType().tsym;
1342 while (localContext != null && !localContext.owner.isStatic()) {
1343 if (localContext.tree.hasTag(LAMBDA)) {
1344 JCTree block = capturedDecl(localContext.depth, outerInstanceSymbol);
1345 if (block == null) break;
1346 ((LambdaTranslationContext)localContext)
1347 .addSymbol(outerInstanceSymbol, CAPTURED_THIS);
1348 }
1349 localContext = localContext.prev;
1350 }
1351 }
1352 }
1353 frameStack = frameStack.prepend(new Frame(tree));
1354 super.visitClassDef(tree);
1355 }
1356 finally {
1357 log.useSource(prevSource.getFile());
1358 frameStack = prevStack;
1359 lambdaCount = prevLambdaCount;
1360 syntheticMethodNameCounts = prevSyntheticMethodNameCounts;
1361 clinits = prevClinits;
1362 }
1363 }
1364
1365 @Override
1366 public void visitIdent(JCIdent tree) {
1367 if (context() != null && lambdaIdentSymbolFilter(tree.sym)) {
1368 if (tree.sym.kind == VAR &&
1369 tree.sym.owner.kind == MTH &&
1370 tree.type.constValue() == null) {
1371 TranslationContext<?> localContext = context();
1372 while (localContext != null) {
1373 if (localContext.tree.getTag() == LAMBDA) {
1374 JCTree block = capturedDecl(localContext.depth, tree.sym);
1375 if (block == null) break;
1376 ((LambdaTranslationContext)localContext)
1377 .addSymbol(tree.sym, CAPTURED_VAR);
1378 }
1379 localContext = localContext.prev;
1380 }
1381 } else if (tree.sym.owner.kind == TYP) {
1382 TranslationContext<?> localContext = context();
1383 while (localContext != null && !localContext.owner.isStatic()) {
1384 if (localContext.tree.hasTag(LAMBDA)) {
1385 JCTree block = capturedDecl(localContext.depth, tree.sym);
1386 if (block == null) break;
1387 switch (block.getTag()) {
1388 case CLASSDEF:
1389 JCClassDecl cdecl = (JCClassDecl)block;
1390 ((LambdaTranslationContext)localContext)
1391 .addSymbol(cdecl.sym, CAPTURED_THIS);
1392 break;
1393 default:
1394 Assert.error("bad block kind");
1395 }
1396 }
1397 localContext = localContext.prev;
1398 }
1399 }
1400 }
1401 super.visitIdent(tree);
1402 }
1403
1404 @Override
1405 public void visitLambda(JCLambda tree) {
1406 analyzeLambda(tree, "lambda.stat");
1407 }
1408
1409 private void analyzeLambda(JCLambda tree, JCExpression methodReferenceReceiver) {
1410 // Translation of the receiver expression must occur first
1411 JCExpression rcvr = translate(methodReferenceReceiver);
1412 LambdaTranslationContext context = analyzeLambda(tree, "mref.stat.1");
1413 if (rcvr != null) {
1414 context.methodReferenceReceiver = rcvr;
1415 }
1416 }
1417
1418 private LambdaTranslationContext analyzeLambda(JCLambda tree, String statKey) {
1419 List<Frame> prevStack = frameStack;
1420 try {
1421 LambdaTranslationContext context = new LambdaTranslationContext(tree);
1422 frameStack = frameStack.prepend(new Frame(tree));
1423 for (JCVariableDecl param : tree.params) {
1424 context.addSymbol(param.sym, PARAM);
1425 frameStack.head.addLocal(param.sym);
1426 }
1427 contextMap.put(tree, context);
1428 super.visitLambda(tree);
1429 context.complete();
1430 if (dumpLambdaToMethodStats) {
1431 log.note(tree, diags.noteKey(statKey, context.needsAltMetafactory(), context.translatedSym));
1432 }
1433 return context;
1434 }
1435 finally {
1436 frameStack = prevStack;
1437 }
1438 }
1439
1440 @Override
1441 public void visitMethodDef(JCMethodDecl tree) {
1442 List<Frame> prevStack = frameStack;
1443 try {
1444 frameStack = frameStack.prepend(new Frame(tree));
1445 super.visitMethodDef(tree);
1446 }
1447 finally {
1448 frameStack = prevStack;
1449 }
1450 }
1451
1452 @Override
1453 public void visitNewClass(JCNewClass tree) {
1454 TypeSymbol def = tree.type.tsym;
1455 boolean inReferencedClass = currentlyInClass(def);
1456 boolean isLocal = def.isDirectlyOrIndirectlyLocal();
1457 if ((inReferencedClass && isLocal || lambdaNewClassFilter(context(), tree))) {
1458 TranslationContext<?> localContext = context();
1459 final TypeSymbol outerInstanceSymbol = tree.type.getEnclosingType().tsym;
1460 while (localContext != null && !localContext.owner.isStatic()) {
1461 if (localContext.tree.hasTag(LAMBDA)) {
1462 if (outerInstanceSymbol != null) {
1463 JCTree block = capturedDecl(localContext.depth, outerInstanceSymbol);
1464 if (block == null) break;
1465 }
1466 ((LambdaTranslationContext)localContext)
1467 .addSymbol(outerInstanceSymbol, CAPTURED_THIS);
1468 }
1469 localContext = localContext.prev;
1470 }
1471 }
1472 super.visitNewClass(tree);
1473 if (context() != null && !inReferencedClass && isLocal) {
1474 LambdaTranslationContext lambdaContext = (LambdaTranslationContext)context();
1475 captureLocalClassDefs(def, lambdaContext);
1476 }
1477 }
1478 //where
1479 void captureLocalClassDefs(Symbol csym, final LambdaTranslationContext lambdaContext) {
1480 JCClassDecl localCDef = localClassDefs.get(csym);
1481 if (localCDef != null && lambdaContext.freeVarProcessedLocalClasses.add(csym)) {
1482 BasicFreeVarCollector fvc = lower.new BasicFreeVarCollector() {
1483 @Override
1484 void addFreeVars(ClassSymbol c) {
1485 captureLocalClassDefs(c, lambdaContext);
1486 }
1487 @Override
1488 void visitSymbol(Symbol sym) {
1489 if (sym.kind == VAR &&
1490 sym.owner.kind == MTH &&
1491 ((VarSymbol)sym).getConstValue() == null) {
1492 TranslationContext<?> localContext = context();
1493 while (localContext != null) {
1494 if (localContext.tree.getTag() == LAMBDA) {
1495 JCTree block = capturedDecl(localContext.depth, sym);
1496 if (block == null) break;
1497 ((LambdaTranslationContext)localContext).addSymbol(sym, CAPTURED_VAR);
1498 }
1499 localContext = localContext.prev;
1500 }
1501 }
1502 }
1503 };
1504 fvc.scan(localCDef);
1505 }
1506 }
1507 //where
1508 boolean currentlyInClass(Symbol csym) {
1509 for (Frame frame : frameStack) {
1510 if (frame.tree.hasTag(JCTree.Tag.CLASSDEF)) {
1511 JCClassDecl cdef = (JCClassDecl) frame.tree;
1512 if (cdef.sym == csym) {
1513 return true;
1514 }
1515 }
1516 }
1517 return false;
1518 }
1519
1520 /**
1521 * Method references to local class constructors, may, if the local
1522 * class references local variables, have implicit constructor
1523 * parameters added in Lower; As a result, the invokedynamic bootstrap
1524 * information added in the LambdaToMethod pass will have the wrong
1525 * signature. Hooks between Lower and LambdaToMethod have been added to
1526 * handle normal "new" in this case. This visitor converts potentially
1527 * affected method references into a lambda containing a normal
1528 * expression.
1529 *
1530 * @param tree
1531 */
1532 @Override
1533 public void visitReference(JCMemberReference tree) {
1534 ReferenceTranslationContext rcontext = new ReferenceTranslationContext(tree);
1535 contextMap.put(tree, rcontext);
1536 if (rcontext.needsConversionToLambda()) {
1537 // Convert to a lambda, and process as such
1538 MemberReferenceToLambda conv = new MemberReferenceToLambda(tree, rcontext, owner());
1539 analyzeLambda(conv.lambda(), conv.getReceiverExpression());
1540 } else {
1541 super.visitReference(tree);
1542 if (dumpLambdaToMethodStats) {
1543 log.note(tree, Notes.MrefStat(rcontext.needsAltMetafactory(), null));
1544 }
1545 }
1546 }
1547
1548 @Override
1549 public void visitSelect(JCFieldAccess tree) {
1550 if (context() != null && tree.sym.kind == VAR &&
1551 (tree.sym.name == names._this ||
1552 tree.sym.name == names._super)) {
1553 // A select of this or super means, if we are in a lambda,
1554 // we much have an instance context
1555 TranslationContext<?> localContext = context();
1556 while (localContext != null && !localContext.owner.isStatic()) {
1557 if (localContext.tree.hasTag(LAMBDA)) {
1558 JCClassDecl clazz = (JCClassDecl)capturedDecl(localContext.depth, tree.sym);
1559 if (clazz == null) break;
1560 ((LambdaTranslationContext)localContext).addSymbol(clazz.sym, CAPTURED_THIS);
1561 }
1562 localContext = localContext.prev;
1563 }
1564 }
1565 super.visitSelect(tree);
1566 }
1567
1568 @Override
1569 public void visitVarDef(JCVariableDecl tree) {
1570 TranslationContext<?> context = context();
1571 if (context != null && context instanceof LambdaTranslationContext lambdaContext) {
1572 if (frameStack.head.tree.hasTag(LAMBDA)) {
1573 lambdaContext.addSymbol(tree.sym, LOCAL_VAR);
1574 }
1575 // Check for type variables (including as type arguments).
1576 // If they occur within class nested in a lambda, mark for erasure
1577 Type type = tree.sym.asType();
1578 }
1579
1580 List<Frame> prevStack = frameStack;
1581 try {
1582 if (tree.sym.owner.kind == MTH) {
1583 frameStack.head.addLocal(tree.sym);
1584 }
1585 frameStack = frameStack.prepend(new Frame(tree));
1586 super.visitVarDef(tree);
1587 }
1588 finally {
1589 frameStack = prevStack;
1590 }
1591 }
1592
1593 /**
1594 * Return a valid owner given the current declaration stack
1595 * (required to skip synthetic lambda symbols)
1596 */
1597 private Symbol owner() {
1598 return owner(false);
1599 }
1600
1601 @SuppressWarnings("fallthrough")
1602 private Symbol owner(boolean skipLambda) {
1603 List<Frame> frameStack2 = frameStack;
1604 while (frameStack2.nonEmpty()) {
1605 switch (frameStack2.head.tree.getTag()) {
1606 case VARDEF:
1607 if (((JCVariableDecl)frameStack2.head.tree).sym.isDirectlyOrIndirectlyLocal()) {
1608 frameStack2 = frameStack2.tail;
1609 break;
1610 }
1611 JCClassDecl cdecl = (JCClassDecl)frameStack2.tail.head.tree;
1612 return initSym(cdecl.sym,
1613 ((JCVariableDecl)frameStack2.head.tree).sym.flags() & STATIC);
1614 case BLOCK:
1615 JCClassDecl cdecl2 = (JCClassDecl)frameStack2.tail.head.tree;
1616 return initSym(cdecl2.sym,
1617 ((JCBlock)frameStack2.head.tree).flags & STATIC);
1618 case CLASSDEF:
1619 return ((JCClassDecl)frameStack2.head.tree).sym;
1620 case METHODDEF:
1621 return ((JCMethodDecl)frameStack2.head.tree).sym;
1622 case LAMBDA:
1623 if (!skipLambda)
1624 return ((LambdaTranslationContext)contextMap
1625 .get(frameStack2.head.tree)).translatedSym;
1626 default:
1627 frameStack2 = frameStack2.tail;
1628 }
1629 }
1630 Assert.error();
1631 return null;
1632 }
1633
1634 private Symbol initSym(ClassSymbol csym, long flags) {
1635 boolean isStatic = (flags & STATIC) != 0;
1636 if (isStatic) {
1637 /* static clinits are generated in Gen, so we need to use a fake
1638 * one. Attr creates a fake clinit method while attributing
1639 * lambda expressions used as initializers of static fields, so
1640 * let's use that one.
1641 */
1642 MethodSymbol clinit = attr.removeClinit(csym);
1643 if (clinit != null) {
1644 clinits.put(csym, clinit);
1645 return clinit;
1646 }
1647
1648 /* if no clinit is found at Attr, then let's try at clinits.
1649 */
1650 clinit = (MethodSymbol)clinits.get(csym);
1651 if (clinit == null) {
1652 /* no luck, let's create a new one
1653 */
1654 clinit = makePrivateSyntheticMethod(STATIC,
1655 names.clinit,
1656 new MethodType(List.nil(), syms.voidType,
1657 List.nil(), syms.methodClass),
1658 csym);
1659 clinits.put(csym, clinit);
1660 }
1661 return clinit;
1662 } else {
1663 //get the first constructor and treat it as the instance init sym
1664 for (Symbol s : csym.members_field.getSymbolsByName(names.init)) {
1665 return s;
1666 }
1667 }
1668 Assert.error("init not found");
1669 return null;
1670 }
1671
1672 private JCTree directlyEnclosingLambda() {
1673 if (frameStack.isEmpty()) {
1674 return null;
1675 }
1676 List<Frame> frameStack2 = frameStack;
1677 while (frameStack2.nonEmpty()) {
1678 switch (frameStack2.head.tree.getTag()) {
1679 case CLASSDEF:
1680 case METHODDEF:
1681 return null;
1682 case LAMBDA:
1683 return frameStack2.head.tree;
1684 default:
1685 frameStack2 = frameStack2.tail;
1686 }
1687 }
1688 Assert.error();
1689 return null;
1690 }
1691
1692 private boolean inClassWithinLambda() {
1693 if (frameStack.isEmpty()) {
1694 return false;
1695 }
1696 List<Frame> frameStack2 = frameStack;
1697 boolean classFound = false;
1698 while (frameStack2.nonEmpty()) {
1699 switch (frameStack2.head.tree.getTag()) {
1700 case LAMBDA:
1701 return classFound;
1702 case CLASSDEF:
1703 classFound = true;
1704 frameStack2 = frameStack2.tail;
1705 break;
1706 default:
1707 frameStack2 = frameStack2.tail;
1708 }
1709 }
1710 // No lambda
1711 return false;
1712 }
1713
1714 /**
1715 * Return the declaration corresponding to a symbol in the enclosing
1716 * scope; the depth parameter is used to filter out symbols defined
1717 * in nested scopes (which do not need to undergo capture).
1718 */
1719 private JCTree capturedDecl(int depth, Symbol sym) {
1720 int currentDepth = frameStack.size() - 1;
1721 for (Frame block : frameStack) {
1722 switch (block.tree.getTag()) {
1723 case CLASSDEF:
1724 ClassSymbol clazz = ((JCClassDecl)block.tree).sym;
1725 if (clazz.isSubClass(sym, types) || sym.isMemberOf(clazz, types)) {
1726 return currentDepth > depth ? null : block.tree;
1727 }
1728 break;
1729 case VARDEF:
1730 if ((((JCVariableDecl)block.tree).sym == sym &&
1731 sym.owner.kind == MTH) || //only locals are captured
1732 (block.locals != null && block.locals.contains(sym))) {
1733 return currentDepth > depth ? null : block.tree;
1734 }
1735 break;
1736 case BLOCK:
1737 case METHODDEF:
1738 case LAMBDA:
1739 if (block.locals != null && block.locals.contains(sym)) {
1740 return currentDepth > depth ? null : block.tree;
1741 }
1742 break;
1743 default:
1744 Assert.error("bad decl kind " + block.tree.getTag());
1745 }
1746 currentDepth--;
1747 }
1748 return null;
1749 }
1750
1751 private TranslationContext<?> context() {
1752 for (Frame frame : frameStack) {
1753 TranslationContext<?> context = contextMap.get(frame.tree);
1754 if (context != null) {
1755 return context;
1756 }
1757 }
1758 return null;
1759 }
1760
1761 /**
1762 * This is used to filter out those identifiers that needs to be adjusted
1763 * when translating away lambda expressions
1764 */
1765 private boolean lambdaIdentSymbolFilter(Symbol sym) {
1766 return (sym.kind == VAR || sym.kind == MTH)
1767 && !sym.isStatic()
1768 && sym.name != names.init;
1769 }
1770
1771 /**
1772 * This is used to filter out those select nodes that need to be adjusted
1773 * when translating away lambda expressions - at the moment, this is the
1774 * set of nodes that select `this' (qualified this)
1775 */
1776 private boolean lambdaFieldAccessFilter(JCFieldAccess fAccess) {
1777 return (context instanceof LambdaTranslationContext lambdaContext)
1778 && !fAccess.sym.isStatic()
1779 && fAccess.name == names._this
1780 && (fAccess.sym.owner.kind == TYP)
1781 && !lambdaContext.translatedSymbols.get(CAPTURED_OUTER_THIS).isEmpty();
1782 }
1783
1784 /**
1785 * This is used to filter out those new class expressions that need to
1786 * be qualified with an enclosing tree
1787 */
1788 private boolean lambdaNewClassFilter(TranslationContext<?> context, JCNewClass tree) {
1789 if (context != null
1790 && tree.encl == null
1791 && tree.def == null
1792 && !tree.type.getEnclosingType().hasTag(NONE)) {
1793 Type encl = tree.type.getEnclosingType();
1794 Type current = context.owner.enclClass().type;
1795 while (!current.hasTag(NONE)) {
1796 if (current.tsym.isSubClass(encl.tsym, types)) {
1797 return true;
1798 }
1799 current = current.getEnclosingType();
1800 }
1801 return false;
1802 } else {
1803 return false;
1804 }
1805 }
1806
1807 private class Frame {
1808 final JCTree tree;
1809 List<Symbol> locals;
1810
1811 public Frame(JCTree tree) {
1812 this.tree = tree;
1813 }
1814
1815 void addLocal(Symbol sym) {
1816 if (locals == null) {
1817 locals = List.nil();
1818 }
1819 locals = locals.prepend(sym);
1820 }
1821 }
1822
1823 /**
1824 * This class is used to store important information regarding translation of
1825 * lambda expression/method references (see subclasses).
1826 */
1827 abstract class TranslationContext<T extends JCFunctionalExpression> {
1828
1829 /** the underlying (untranslated) tree */
1830 final T tree;
1831
1832 /** points to the adjusted enclosing scope in which this lambda/mref expression occurs */
1833 final Symbol owner;
1834
1835 /** the depth of this lambda expression in the frame stack */
1836 final int depth;
1837
1838 /** the enclosing translation context (set for nested lambdas/mref) */
1839 final TranslationContext<?> prev;
1840
1841 /** list of methods to be bridged by the meta-factory */
1842 final List<Symbol> bridges;
1843
1844 TranslationContext(T tree) {
1845 this.tree = tree;
1846 this.owner = owner(true);
1847 this.depth = frameStack.size() - 1;
1848 this.prev = context();
1849 ClassSymbol csym =
1850 types.makeFunctionalInterfaceClass(attrEnv, names.empty, tree.target, ABSTRACT | INTERFACE);
1851 this.bridges = types.functionalInterfaceBridges(csym);
1852 }
1853
1854 /** does this functional expression need to be created using alternate metafactory? */
1855 boolean needsAltMetafactory() {
1856 return tree.target.isIntersection() ||
1857 isSerializable() ||
1858 bridges.length() > 1;
1859 }
1860
1861 /** does this functional expression require serialization support? */
1862 boolean isSerializable() {
1863 if (forceSerializable) {
1864 return true;
1865 }
1866 return types.asSuper(tree.target, syms.serializableType.tsym) != null;
1867 }
1868
1869 /**
1870 * @return Name of the enclosing method to be folded into synthetic
1871 * method name
1872 */
1873 String enclosingMethodName() {
1874 return syntheticMethodNameComponent(owner.name);
1875 }
1876
1877 /**
1878 * @return Method name in a form that can be folded into a
1879 * component of a synthetic method name
1880 */
1881 String syntheticMethodNameComponent(Name name) {
1882 if (name == null) {
1883 return "null";
1884 }
1885 String methodName = name.toString();
1886 if (methodName.equals("<clinit>")) {
1887 methodName = "static";
1888 } else if (methodName.equals("<init>")) {
1889 methodName = "new";
1890 }
1891 return methodName;
1892 }
1893 }
1894
1895 /**
1896 * This class retains all the useful information about a lambda expression;
1897 * the contents of this class are filled by the LambdaAnalyzer visitor,
1898 * and the used by the main translation routines in order to adjust references
1899 * to captured locals/members, etc.
1900 */
1901 class LambdaTranslationContext extends TranslationContext<JCLambda> {
1902
1903 /** variable in the enclosing context to which this lambda is assigned */
1904 final Symbol self;
1905
1906 /** variable in the enclosing context to which this lambda is assigned */
1907 final Symbol assignedTo;
1908
1909 Map<LambdaSymbolKind, Map<Symbol, Symbol>> translatedSymbols;
1910
1911 /** the synthetic symbol for the method hoisting the translated lambda */
1912 MethodSymbol translatedSym;
1913
1914 List<JCVariableDecl> syntheticParams;
1915
1916 /**
1917 * to prevent recursion, track local classes processed
1918 */
1919 final Set<Symbol> freeVarProcessedLocalClasses;
1920
1921 /**
1922 * For method references converted to lambdas. The method
1923 * reference receiver expression. Must be treated like a captured
1924 * variable.
1925 */
1926 JCExpression methodReferenceReceiver;
1927
1928 LambdaTranslationContext(JCLambda tree) {
1929 super(tree);
1930 Frame frame = frameStack.head;
1931 switch (frame.tree.getTag()) {
1932 case VARDEF:
1933 assignedTo = self = ((JCVariableDecl) frame.tree).sym;
1934 break;
1935 case ASSIGN:
1936 self = null;
1937 assignedTo = TreeInfo.symbol(((JCAssign) frame.tree).getVariable());
1938 break;
1939 default:
1940 assignedTo = self = null;
1941 break;
1942 }
1943
1944 // This symbol will be filled-in in complete
1945 if (owner.kind == MTH) {
1946 final MethodSymbol originalOwner = (MethodSymbol)owner.clone(owner.owner);
1947 this.translatedSym = new MethodSymbol(SYNTHETIC | PRIVATE, null, null, owner.enclClass()) {
1948 @Override
1949 public MethodSymbol originalEnclosingMethod() {
1950 return originalOwner;
1951 }
1952 };
1953 } else {
1954 this.translatedSym = makePrivateSyntheticMethod(0, null, null, owner.enclClass());
1955 }
1956 translatedSymbols = new EnumMap<>(LambdaSymbolKind.class);
1957
1958 translatedSymbols.put(PARAM, new LinkedHashMap<Symbol, Symbol>());
1959 translatedSymbols.put(LOCAL_VAR, new LinkedHashMap<Symbol, Symbol>());
1960 translatedSymbols.put(CAPTURED_VAR, new LinkedHashMap<Symbol, Symbol>());
1961 translatedSymbols.put(CAPTURED_THIS, new LinkedHashMap<Symbol, Symbol>());
1962 translatedSymbols.put(CAPTURED_OUTER_THIS, new LinkedHashMap<Symbol, Symbol>());
1963
1964 freeVarProcessedLocalClasses = new HashSet<>();
1965 }
1966
1967 /**
1968 * For a serializable lambda, generate a disambiguating string
1969 * which maximizes stability across deserialization.
1970 *
1971 * @return String to differentiate synthetic lambda method names
1972 */
1973 private String serializedLambdaDisambiguation() {
1974 StringBuilder buf = new StringBuilder();
1975 // Append the enclosing method signature to differentiate
1976 // overloaded enclosing methods. For lambdas enclosed in
1977 // lambdas, the generated lambda method will not have type yet,
1978 // but the enclosing method's name will have been generated
1979 // with this same method, so it will be unique and never be
1980 // overloaded.
1981 Assert.check(
1982 owner.type != null ||
1983 directlyEnclosingLambda() != null);
1984 if (owner.type != null) {
1985 buf.append(typeSig(owner.type, true));
1986 buf.append(":");
1987 }
1988
1989 // Add target type info
1990 buf.append(types.findDescriptorSymbol(tree.type.tsym).owner.flatName());
1991 buf.append(" ");
1992
1993 // Add variable assigned to
1994 if (assignedTo != null) {
1995 buf.append(assignedTo.flatName());
1996 buf.append("=");
1997 }
1998 //add captured locals info: type, name, order
1999 for (Symbol fv : getSymbolMap(CAPTURED_VAR).keySet()) {
2000 if (fv != self) {
2001 buf.append(typeSig(fv.type, true));
2002 buf.append(" ");
2003 buf.append(fv.flatName());
2004 buf.append(",");
2005 }
2006 }
2007
2008 return buf.toString();
2009 }
2010
2011 /**
2012 * For a non-serializable lambda, generate a simple method.
2013 *
2014 * @return Name to use for the synthetic lambda method name
2015 */
2016 private Name lambdaName() {
2017 return names.lambda.append(names.fromString(enclosingMethodName() + "$" + lambdaCount++));
2018 }
2019
2020 /**
2021 * For a serializable lambda, generate a method name which maximizes
2022 * name stability across deserialization.
2023 *
2024 * @return Name to use for the synthetic lambda method name
2025 */
2026 private Name serializedLambdaName() {
2027 StringBuilder buf = new StringBuilder();
2028 buf.append(names.lambda);
2029 // Append the name of the method enclosing the lambda.
2030 buf.append(enclosingMethodName());
2031 buf.append('$');
2032 // Append a hash of the disambiguating string : enclosing method
2033 // signature, etc.
2034 String disam = serializedLambdaDisambiguation();
2035 buf.append(Integer.toHexString(disam.hashCode()));
2036 buf.append('$');
2037 // The above appended name components may not be unique, append
2038 // a count based on the above name components.
2039 buf.append(syntheticMethodNameCounts.getIndex(buf));
2040 String result = buf.toString();
2041 //System.err.printf("serializedLambdaName: %s -- %s\n", result, disam);
2042 return names.fromString(result);
2043 }
2044
2045 /**
2046 * Translate a symbol of a given kind into something suitable for the
2047 * synthetic lambda body
2048 */
2049 Symbol translate(final Symbol sym, LambdaSymbolKind skind) {
2050 Symbol ret;
2051 switch (skind) {
2052 case CAPTURED_THIS:
2053 ret = sym; // self represented
2054 break;
2055 case CAPTURED_VAR:
2056 ret = new VarSymbol(SYNTHETIC | FINAL | PARAMETER, sym.name, types.erasure(sym.type), translatedSym) {
2057 @Override
2058 public Symbol baseSymbol() {
2059 //keep mapping with original captured symbol
2060 return sym;
2061 }
2062 };
2063 break;
2064 case CAPTURED_OUTER_THIS:
2065 Name name = names.fromString(sym.flatName().toString().replace('.', '$') + names.dollarThis);
2066 ret = new VarSymbol(SYNTHETIC | FINAL | PARAMETER, name, types.erasure(sym.type), translatedSym) {
2067 @Override
2068 public Symbol baseSymbol() {
2069 //keep mapping with original captured symbol
2070 return sym;
2071 }
2072 };
2073 break;
2074 case LOCAL_VAR:
2075 ret = new VarSymbol(sym.flags() & FINAL, sym.name, sym.type, translatedSym) {
2076 @Override
2077 public Symbol baseSymbol() {
2078 //keep mapping with original symbol
2079 return sym;
2080 }
2081 };
2082 ((VarSymbol) ret).pos = ((VarSymbol) sym).pos;
2083 // If sym.data == ElementKind.EXCEPTION_PARAMETER,
2084 // set ret.data = ElementKind.EXCEPTION_PARAMETER too.
2085 // Because method com.sun.tools.javac.jvm.Code.fillExceptionParameterPositions and
2086 // com.sun.tools.javac.jvm.Code.fillLocalVarPosition would use it.
2087 // See JDK-8257740 for more information.
2088 if (((VarSymbol) sym).isExceptionParameter()) {
2089 ((VarSymbol) ret).setData(ElementKind.EXCEPTION_PARAMETER);
2090 }
2091 break;
2092 case PARAM:
2093 ret = new VarSymbol((sym.flags() & FINAL) | PARAMETER, sym.name, types.erasure(sym.type), translatedSym);
2094 ((VarSymbol) ret).pos = ((VarSymbol) sym).pos;
2095 // Set ret.data. Same as case LOCAL_VAR above.
2096 if (((VarSymbol) sym).isExceptionParameter()) {
2097 ((VarSymbol) ret).setData(ElementKind.EXCEPTION_PARAMETER);
2098 }
2099 break;
2100 default:
2101 Assert.error(skind.name());
2102 throw new AssertionError();
2103 }
2104 if (ret != sym && skind.propagateAnnotations()) {
2105 ret.setDeclarationAttributes(sym.getRawAttributes());
2106 ret.setTypeAttributes(sym.getRawTypeAttributes());
2107 }
2108 return ret;
2109 }
2110
2111 void addSymbol(Symbol sym, LambdaSymbolKind skind) {
2112 if (skind == CAPTURED_THIS && sym != null && sym.kind == TYP && !typesUnderConstruction.isEmpty()) {
2113 ClassSymbol currentClass = currentClass();
2114 if (currentClass != null && typesUnderConstruction.contains(currentClass)) {
2115 // reference must be to enclosing outer instance, mutate capture kind.
2116 Assert.check(sym != currentClass); // should have been caught right in Attr
2117 skind = CAPTURED_OUTER_THIS;
2118 }
2119 }
2120 Map<Symbol, Symbol> transMap = getSymbolMap(skind);
2121 if (!transMap.containsKey(sym)) {
2122 transMap.put(sym, translate(sym, skind));
2123 }
2124 }
2125
2126 Map<Symbol, Symbol> getSymbolMap(LambdaSymbolKind skind) {
2127 Map<Symbol, Symbol> m = translatedSymbols.get(skind);
2128 Assert.checkNonNull(m);
2129 return m;
2130 }
2131
2132 JCTree translate(JCIdent lambdaIdent) {
2133 for (LambdaSymbolKind kind : LambdaSymbolKind.values()) {
2134 Map<Symbol, Symbol> m = getSymbolMap(kind);
2135 switch(kind) {
2136 default:
2137 if (m.containsKey(lambdaIdent.sym)) {
2138 Symbol tSym = m.get(lambdaIdent.sym);
2139 JCTree t = make.Ident(tSym).setType(lambdaIdent.type);
2140 return t;
2141 }
2142 break;
2143 case CAPTURED_OUTER_THIS:
2144 Optional<Symbol> proxy = m.keySet().stream()
2145 .filter(out -> lambdaIdent.sym.isMemberOf(out.type.tsym, types))
2146 .reduce((a, b) -> a.isEnclosedBy((ClassSymbol)b) ? a : b);
2147 if (proxy.isPresent()) {
2148 // Transform outer instance variable references anchoring them to the captured synthetic.
2149 Symbol tSym = m.get(proxy.get());
2150 JCExpression t = make.Ident(tSym).setType(lambdaIdent.sym.owner.type);
2151 t = make.Select(t, lambdaIdent.name);
2152 t.setType(lambdaIdent.type);
2153 TreeInfo.setSymbol(t, lambdaIdent.sym);
2154 return t;
2155 }
2156 break;
2157 }
2158 }
2159 return null;
2160 }
2161
2162 /* Translate away qualified this expressions, anchoring them to synthetic parameters that
2163 capture the qualified this handle. `fieldAccess' is guaranteed to one such.
2164 */
2165 public JCTree translate(JCFieldAccess fieldAccess) {
2166 Assert.check(fieldAccess.name == names._this);
2167 Map<Symbol, Symbol> m = translatedSymbols.get(LambdaSymbolKind.CAPTURED_OUTER_THIS);
2168 if (m.containsKey(fieldAccess.sym.owner)) {
2169 Symbol tSym = m.get(fieldAccess.sym.owner);
2170 JCExpression t = make.Ident(tSym).setType(fieldAccess.sym.owner.type);
2171 return t;
2172 }
2173 return null;
2174 }
2175
2176 /* Translate away naked new instance creation expressions with implicit enclosing instances,
2177 anchoring them to synthetic parameters that stand proxy for the qualified outer this handle.
2178 */
2179 public JCNewClass translate(JCNewClass newClass) {
2180 Assert.check(newClass.clazz.type.tsym.hasOuterInstance() && newClass.encl == null);
2181 Map<Symbol, Symbol> m = translatedSymbols.get(LambdaSymbolKind.CAPTURED_OUTER_THIS);
2182 final Type enclosingType = newClass.clazz.type.getEnclosingType();
2183 if (m.containsKey(enclosingType.tsym)) {
2184 Symbol tSym = m.get(enclosingType.tsym);
2185 JCExpression encl = make.Ident(tSym).setType(enclosingType);
2186 newClass.encl = encl;
2187 }
2188 return newClass;
2189 }
2190
2191 /**
2192 * The translatedSym is not complete/accurate until the analysis is
2193 * finished. Once the analysis is finished, the translatedSym is
2194 * "completed" -- updated with type information, access modifiers,
2195 * and full parameter list.
2196 */
2197 void complete() {
2198 if (syntheticParams != null) {
2199 return;
2200 }
2201 boolean inInterface = translatedSym.owner.isInterface();
2202 boolean thisReferenced = !getSymbolMap(CAPTURED_THIS).isEmpty();
2203
2204 // If instance access isn't needed, make it static.
2205 // Interface instance methods must be default methods.
2206 // Lambda methods are private synthetic.
2207 // Inherit ACC_STRICT from the enclosing method, or, for clinit,
2208 // from the class.
2209 translatedSym.flags_field = SYNTHETIC | LAMBDA_METHOD |
2210 owner.flags_field & STRICTFP |
2211 owner.owner.flags_field & STRICTFP |
2212 PRIVATE |
2213 (thisReferenced? (inInterface? DEFAULT : 0) : STATIC);
2214
2215 //compute synthetic params
2216 ListBuffer<JCVariableDecl> params = new ListBuffer<>();
2217 ListBuffer<VarSymbol> parameterSymbols = new ListBuffer<>();
2218
2219 // The signature of the method is augmented with the following
2220 // synthetic parameters:
2221 //
2222 // 1) reference to enclosing contexts captured by the lambda expression
2223 // 2) enclosing locals captured by the lambda expression
2224 for (Symbol thisSym : getSymbolMap(CAPTURED_VAR).values()) {
2225 params.append(make.VarDef((VarSymbol) thisSym, null));
2226 parameterSymbols.append((VarSymbol) thisSym);
2227 }
2228 for (Symbol thisSym : getSymbolMap(CAPTURED_OUTER_THIS).values()) {
2229 params.append(make.VarDef((VarSymbol) thisSym, null));
2230 parameterSymbols.append((VarSymbol) thisSym);
2231 }
2232 for (Symbol thisSym : getSymbolMap(PARAM).values()) {
2233 params.append(make.VarDef((VarSymbol) thisSym, null));
2234 parameterSymbols.append((VarSymbol) thisSym);
2235 }
2236 syntheticParams = params.toList();
2237
2238 translatedSym.params = parameterSymbols.toList();
2239
2240 // Compute and set the lambda name
2241 translatedSym.name = isSerializable()
2242 ? serializedLambdaName()
2243 : lambdaName();
2244
2245 //prepend synthetic args to translated lambda method signature
2246 translatedSym.type = types.createMethodTypeWithParameters(
2247 generatedLambdaSig(),
2248 TreeInfo.types(syntheticParams));
2249 }
2250
2251 Type generatedLambdaSig() {
2252 return types.erasure(tree.getDescriptorType(types));
2253 }
2254 }
2255
2256 /**
2257 * This class retains all the useful information about a method reference;
2258 * the contents of this class are filled by the LambdaAnalyzer visitor,
2259 * and the used by the main translation routines in order to adjust method
2260 * references (i.e. in case a bridge is needed)
2261 */
2262 final class ReferenceTranslationContext extends TranslationContext<JCMemberReference> {
2263
2264 final boolean isSuper;
2265
2266 ReferenceTranslationContext(JCMemberReference tree) {
2267 super(tree);
2268 this.isSuper = tree.hasKind(ReferenceKind.SUPER);
2269 }
2270
2271 boolean needsVarArgsConversion() {
2272 return tree.varargsElement != null;
2273 }
2274
2275 /**
2276 * @return Is this an array operation like clone()
2277 */
2278 boolean isArrayOp() {
2279 return tree.sym.owner == syms.arrayClass;
2280 }
2281
2282 boolean receiverAccessible() {
2283 //hack needed to workaround 292 bug (7087658)
2284 //when 292 issue is fixed we should remove this and change the backend
2285 //code to always generate a method handle to an accessible method
2286 return tree.ownerAccessible;
2287 }
2288
2289 /**
2290 * This method should be called only when target release <= 14
2291 * where LambdaMetaFactory does not spin nestmate classes.
2292 *
2293 * This method should be removed when --release 14 is not supported.
2294 */
2295 boolean isPrivateInOtherClass() {
2296 assert !nestmateLambdas;
2297 return (tree.sym.flags() & PRIVATE) != 0 &&
2298 !types.isSameType(
2299 types.erasure(tree.sym.enclClass().asType()),
2300 types.erasure(owner.enclClass().asType()));
2301 }
2302
2303 /**
2304 * Erasure destroys the implementation parameter subtype
2305 * relationship for intersection types.
2306 * Have similar problems for union types too.
2307 */
2308 boolean interfaceParameterIsIntersectionOrUnionType() {
2309 List<Type> tl = tree.getDescriptorType(types).getParameterTypes();
2310 for (; tl.nonEmpty(); tl = tl.tail) {
2311 Type pt = tl.head;
2312 if (isIntersectionOrUnionType(pt))
2313 return true;
2314 }
2315 return false;
2316 }
2317
2318 boolean isIntersectionOrUnionType(Type t) {
2319 switch (t.getKind()) {
2320 case INTERSECTION:
2321 case UNION:
2322 return true;
2323 case TYPEVAR:
2324 TypeVar tv = (TypeVar) t;
2325 return isIntersectionOrUnionType(tv.getUpperBound());
2326 }
2327 return false;
2328 }
2329
2330 /**
2331 * Does this reference need to be converted to a lambda
2332 * (i.e. var args need to be expanded or "super" is used)
2333 */
2334 final boolean needsConversionToLambda() {
2335 return interfaceParameterIsIntersectionOrUnionType() ||
2336 isSuper ||
2337 needsVarArgsConversion() ||
2338 isArrayOp() ||
2339 (!nestmateLambdas && isPrivateInOtherClass()) ||
2340 isProtectedInSuperClassOfEnclosingClassInOtherPackage(tree.sym, owner) ||
2341 !receiverAccessible() ||
2342 (tree.getMode() == ReferenceMode.NEW &&
2343 tree.kind != ReferenceKind.ARRAY_CTOR &&
2344 (tree.sym.owner.isDirectlyOrIndirectlyLocal() || tree.sym.owner.isInner()));
2345 }
2346
2347 Type generatedRefSig() {
2348 return types.erasure(tree.sym.type);
2349 }
2350
2351 Type bridgedRefSig() {
2352 return types.erasure(types.findDescriptorSymbol(tree.target.tsym).type);
2353 }
2354 }
2355 }
2356 // </editor-fold>
2357
2358 /*
2359 * These keys provide mappings for various translated lambda symbols
2360 * and the prevailing order must be maintained.
2361 */
2362 enum LambdaSymbolKind {
2363 PARAM, // original to translated lambda parameters
2364 LOCAL_VAR, // original to translated lambda locals
2365 CAPTURED_VAR, // variables in enclosing scope to translated synthetic parameters
2366 CAPTURED_THIS, // class symbols to translated synthetic parameters (for captured member access)
2367 CAPTURED_OUTER_THIS; // used when `this' capture is illegal, but outer this capture is legit (JDK-8129740)
2368
2369 boolean propagateAnnotations() {
2370 switch (this) {
2371 case CAPTURED_VAR:
2372 case CAPTURED_THIS:
2373 case CAPTURED_OUTER_THIS:
2374 return false;
2375 default:
2376 return true;
2377 }
2378 }
2379 }
2380
2381 /**
2382 * ****************************************************************
2383 * Signature Generation
2384 * ****************************************************************
2385 */
2386
2387 private String typeSig(Type type) {
2388 return typeSig(type, false);
2389 }
2390
2391 private String typeSig(Type type, boolean allowIllegalSignature) {
2392 try {
2393 L2MSignatureGenerator sg = new L2MSignatureGenerator(allowIllegalSignature);
2394 sg.assembleSig(type);
2395 return sg.toString();
2396 } catch (InvalidSignatureException ex) {
2397 Symbol c = attrEnv.enclClass.sym;
2398 log.error(Errors.CannotGenerateClass(c, Fragments.IllegalSignature(c, ex.type())));
2399 return "<ERRONEOUS>";
2400 }
2401 }
2402
2403 private String classSig(Type type) {
2404 try {
2405 L2MSignatureGenerator sg = new L2MSignatureGenerator(false);
2406 sg.assembleClassSig(type);
2407 return sg.toString();
2408 } catch (InvalidSignatureException ex) {
2409 Symbol c = attrEnv.enclClass.sym;
2410 log.error(Errors.CannotGenerateClass(c, Fragments.IllegalSignature(c, ex.type())));
2411 return "<ERRONEOUS>";
2412 }
2413 }
2414
2415 private boolean isProtectedInSuperClassOfEnclosingClassInOtherPackage(Symbol targetReference,
2416 Symbol currentClass) {
2417 return ((targetReference.flags() & PROTECTED) != 0 &&
2418 targetReference.packge() != currentClass.packge());
2419 }
2420
2421 /**
2422 * Signature Generation
2423 */
2424 private class L2MSignatureGenerator extends Types.SignatureGenerator {
2425
2426 /**
2427 * An output buffer for type signatures.
2428 */
2429 StringBuilder sb = new StringBuilder();
2430
2431 /**
2432 * Are signatures incompatible with JVM spec allowed?
2433 * Used by {@link LambdaTranslationContext#serializedLambdaDisambiguation()}.
2434 */
2435 boolean allowIllegalSignatures;
2436
2437 L2MSignatureGenerator(boolean allowIllegalSignatures) {
2438 super(types);
2439 this.allowIllegalSignatures = allowIllegalSignatures;
2440 }
2441
2442 @Override
2443 protected void reportIllegalSignature(Type t) {
2444 if (!allowIllegalSignatures) {
2445 super.reportIllegalSignature(t);
2446 }
2447 }
2448
2449 @Override
2450 protected void append(char ch) {
2451 sb.append(ch);
2452 }
2453
2454 @Override
2455 protected void append(byte[] ba) {
2456 Name name;
2457 try {
2458 name = names.fromUtf(ba);
2459 } catch (InvalidUtfException e) {
2460 throw new AssertionError(e);
2461 }
2462 sb.append(name.toString());
2463 }
2464
2465 @Override
2466 protected void append(Name name) {
2467 sb.append(name.toString());
2468 }
2469
2470 @Override
2471 public String toString() {
2472 return sb.toString();
2473 }
2474 }
2475 }