1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
|
/* NSC -- new Scala compiler
* Copyright 2005-2012 LAMP/EPFL
* @author Martin Odersky
*/
package scala
package tools.nsc
package backend.jvm
import scala.tools.asm
import scala.annotation.switch
import scala.collection.{ immutable, mutable }
import scala.tools.nsc.io.AbstractFile
/*
* Traits encapsulating functionality to convert Scala AST Trees into ASM ClassNodes.
*
* @author Miguel Garcia, http://lamp.epfl.ch/~magarcia/ScalaCompilerCornerReloaded
* @version 1.0
*
*/
abstract class BCodeHelpers extends BCodeTypes with BytecodeWriters {
import global._
/*
* must-single-thread
*/
def getFileForClassfile(base: AbstractFile, clsName: String, suffix: String): AbstractFile = {
getFile(base, clsName, suffix)
}
/*
* must-single-thread
*/
def getOutFolder(csym: Symbol, cName: String, cunit: CompilationUnit): _root_.scala.tools.nsc.io.AbstractFile = {
try {
outputDirectory(csym)
} catch {
case ex: Throwable =>
cunit.error(cunit.body.pos, s"Couldn't create file for class $cName\n${ex.getMessage}")
null
}
}
var pickledBytes = 0 // statistics
// -----------------------------------------------------------------------------------------
// finding the least upper bound in agreement with the bytecode verifier (given two internal names handed by ASM)
// Background:
// http://gallium.inria.fr/~xleroy/publi/bytecode-verification-JAR.pdf
// http://comments.gmane.org/gmane.comp.java.vm.languages/2293
// https://issues.scala-lang.org/browse/SI-3872
// -----------------------------------------------------------------------------------------
/*
* can-multi-thread
*/
def firstCommonSuffix(as: List[Tracked], bs: List[Tracked]): BType = {
var chainA = as
var chainB = bs
var fcs: Tracked = null
do {
if (chainB contains chainA.head) fcs = chainA.head
else if (chainA contains chainB.head) fcs = chainB.head
else {
chainA = chainA.tail
chainB = chainB.tail
}
} while (fcs == null)
fcs.c
}
/* An `asm.ClassWriter` that uses `jvmWiseLUB()`
* The internal name of the least common ancestor of the types given by inameA and inameB.
* It's what ASM needs to know in order to compute stack map frames, http://asm.ow2.org/doc/developer-guide.html#controlflow
*/
final class CClassWriter(flags: Int) extends asm.ClassWriter(flags) {
/*
* This method is thread re-entrant because chrs never grows during its operation (that's because all TypeNames being looked up have already been entered).
* To stress this point, rather than using `newTypeName()` we use `lookupTypeName()`
*
* can-multi-thread
*/
override def getCommonSuperClass(inameA: String, inameB: String): String = {
val a = brefType(lookupTypeName(inameA.toCharArray))
val b = brefType(lookupTypeName(inameB.toCharArray))
val lca = jvmWiseLUB(a, b)
val lcaName = lca.getInternalName // don't call javaName because that side-effects innerClassBuffer.
assert(lcaName != "scala/Any")
lcaName // ASM caches the answer during the lifetime of a ClassWriter. We outlive that. Not sure whether caching on our side would improve things.
}
}
/*
* Finding the least upper bound in agreement with the bytecode verifier (given two internal names handed out by ASM)
* Background:
* http://gallium.inria.fr/~xleroy/publi/bytecode-verification-JAR.pdf
* http://comments.gmane.org/gmane.comp.java.vm.languages/2293
* https://issues.scala-lang.org/browse/SI-3872
*
* can-multi-thread
*/
def jvmWiseLUB(a: BType, b: BType): BType = {
assert(a.isNonSpecial, s"jvmWiseLUB() received a non-plain-class $a")
assert(b.isNonSpecial, s"jvmWiseLUB() received a non-plain-class $b")
val ta = exemplars.get(a)
val tb = exemplars.get(b)
val res = (ta.isInterface, tb.isInterface) match {
case (true, true) =>
// exercised by test/files/run/t4761.scala
if (tb.isSubtypeOf(ta.c)) ta.c
else if (ta.isSubtypeOf(tb.c)) tb.c
else ObjectReference
case (true, false) =>
if (tb.isSubtypeOf(a)) a else ObjectReference
case (false, true) =>
if (ta.isSubtypeOf(b)) b else ObjectReference
case _ =>
firstCommonSuffix(ta :: ta.superClasses, tb :: tb.superClasses)
}
assert(res.isNonSpecial, "jvmWiseLUB() returned a non-plain-class.")
res
}
/*
* must-single-thread
*/
object isJavaEntryPoint {
/*
* must-single-thread
*/
def apply(sym: Symbol, csymCompUnit: CompilationUnit): Boolean = {
def fail(msg: String, pos: Position = sym.pos) = {
csymCompUnit.warning(sym.pos,
sym.name +
s" has a main method with parameter type Array[String], but ${sym.fullName('.')} will not be a runnable program.\n Reason: $msg"
// TODO: make this next claim true, if possible
// by generating valid main methods as static in module classes
// not sure what the jvm allows here
// + " You can still run the program by calling it as " + sym.javaSimpleName + " instead."
)
false
}
def failNoForwarder(msg: String) = {
fail(s"$msg, which means no static forwarder can be generated.\n")
}
val possibles = if (sym.hasModuleFlag) (sym.tpe nonPrivateMember nme.main).alternatives else Nil
val hasApproximate = possibles exists { m =>
m.info match {
case MethodType(p :: Nil, _) => p.tpe.typeSymbol == definitions.ArrayClass
case _ => false
}
}
// At this point it's a module with a main-looking method, so either succeed or warn that it isn't.
hasApproximate && {
// Before erasure so we can identify generic mains.
enteringErasure {
val companion = sym.linkedClassOfClass
if (definitions.hasJavaMainMethod(companion))
failNoForwarder("companion contains its own main method")
else if (companion.tpe.member(nme.main) != NoSymbol)
// this is only because forwarders aren't smart enough yet
failNoForwarder("companion contains its own main method (implementation restriction: no main is allowed, regardless of signature)")
else if (companion.isTrait)
failNoForwarder("companion is a trait")
// Now either succeeed, or issue some additional warnings for things which look like
// attempts to be java main methods.
else (possibles exists definitions.isJavaMainMethod) || {
possibles exists { m =>
m.info match {
case PolyType(_, _) =>
fail("main methods cannot be generic.")
case MethodType(params, res) =>
if (res.typeSymbol :: params exists (_.isAbstractType))
fail("main methods cannot refer to type parameters or abstract types.", m.pos)
else
definitions.isJavaMainMethod(m) || fail("main method must have exact signature (Array[String])Unit", m.pos)
case tp =>
fail(s"don't know what this is: $tp", m.pos)
}
}
}
}
}
}
}
/*
* must-single-thread
*/
def initBytecodeWriter(entryPoints: List[Symbol]): BytecodeWriter = {
settings.outputDirs.getSingleOutput match {
case Some(f) if f hasExtension "jar" =>
// If no main class was specified, see if there's only one
// entry point among the classes going into the jar.
if (settings.mainClass.isDefault) {
entryPoints map (_.fullName('.')) match {
case Nil =>
log("No Main-Class designated or discovered.")
case name :: Nil =>
log(s"Unique entry point: setting Main-Class to $name")
settings.mainClass.value = name
case names =>
log(s"No Main-Class due to multiple entry points:\n ${names.mkString("\n ")}")
}
}
else log(s"Main-Class was specified: ${settings.mainClass.value}")
new DirectToJarfileWriter(f.file)
case _ => factoryNonJarBytecodeWriter()
}
}
/*
* must-single-thread
*/
def fieldSymbols(cls: Symbol): List[Symbol] = {
for (f <- cls.info.decls.toList ;
if !f.isMethod && f.isTerm && !f.isModule
) yield f;
}
/*
* can-multi-thread
*/
def methodSymbols(cd: ClassDef): List[Symbol] = {
cd.impl.body collect { case dd: DefDef => dd.symbol }
}
/*
* must-single-thread
*/
def serialVUID(csym: Symbol): Option[Long] = csym getAnnotation definitions.SerialVersionUIDAttr collect {
case AnnotationInfo(_, _, (_, LiteralAnnotArg(const)) :: Nil) => const.longValue
}
/*
* Populates the InnerClasses JVM attribute with `refedInnerClasses`.
* In addition to inner classes mentioned somewhere in `jclass` (where `jclass` is a class file being emitted)
* `refedInnerClasses` should contain those inner classes defined as direct member classes of `jclass`
* but otherwise not mentioned in `jclass`.
*
* `refedInnerClasses` may contain duplicates,
* need not contain the enclosing inner classes of each inner class it lists (those are looked up for consistency).
*
* This method serializes in the InnerClasses JVM attribute in an appropriate order,
* not necessarily that given by `refedInnerClasses`.
*
* can-multi-thread
*/
final def addInnerClassesASM(jclass: asm.ClassVisitor, refedInnerClasses: Iterable[BType]) {
// used to detect duplicates.
val seen = mutable.Map.empty[String, String]
// result without duplicates, not yet sorted.
val result = mutable.Set.empty[InnerClassEntry]
for(s: BType <- refedInnerClasses;
e: InnerClassEntry <- exemplars.get(s).innersChain) {
assert(e.name != null, "saveInnerClassesFor() is broken.") // documentation
val doAdd = seen.get(e.name) match {
// TODO is it ok for prevOName to be null? (Someone should really document the invariants of the InnerClasses bytecode attribute)
case Some(prevOName) =>
// this occurs e.g. when innerClassBuffer contains both class Thread$State, object Thread$State,
// i.e. for them it must be the case that oname == java/lang/Thread
assert(prevOName == e.outerName, "duplicate")
false
case None => true
}
if (doAdd) {
seen += (e.name -> e.outerName)
result += e
}
}
// sorting ensures inner classes are listed after their enclosing class thus satisfying the Eclipse Java compiler
for(e <- result.toList sortBy (_.name.toString)) {
jclass.visitInnerClass(e.name, e.outerName, e.innerName, e.access)
}
} // end of method addInnerClassesASM()
/*
* Custom attribute (JVMS 4.7.1) "ScalaSig" used as marker only
* i.e., the pickle is contained in a custom annotation, see:
* (1) `addAnnotations()`,
* (2) SID # 10 (draft) - Storage of pickled Scala signatures in class files, http://www.scala-lang.org/sid/10
* (3) SID # 5 - Internals of Scala Annotations, http://www.scala-lang.org/sid/5
* That annotation in turn is not related to the "java-generic-signature" (JVMS 4.7.9)
* other than both ending up encoded as attributes (JVMS 4.7)
* (with the caveat that the "ScalaSig" attribute is associated to some classes,
* while the "Signature" attribute can be associated to classes, methods, and fields.)
*
*/
trait BCPickles {
import scala.reflect.internal.pickling.{ PickleFormat, PickleBuffer }
val versionPickle = {
val vp = new PickleBuffer(new Array[Byte](16), -1, 0)
assert(vp.writeIndex == 0, vp)
vp writeNat PickleFormat.MajorVersion
vp writeNat PickleFormat.MinorVersion
vp writeNat 0
vp
}
/*
* can-multi-thread
*/
def createJAttribute(name: String, b: Array[Byte], offset: Int, len: Int): asm.Attribute = {
val dest = new Array[Byte](len);
System.arraycopy(b, offset, dest, 0, len);
new asm.CustomAttr(name, dest)
}
/*
* can-multi-thread
*/
def pickleMarkerLocal = {
createJAttribute(tpnme.ScalaSignatureATTR.toString, versionPickle.bytes, 0, versionPickle.writeIndex)
}
/*
* can-multi-thread
*/
def pickleMarkerForeign = {
createJAttribute(tpnme.ScalaATTR.toString, new Array[Byte](0), 0, 0)
}
/* Returns a ScalaSignature annotation if it must be added to this class, none otherwise.
* This annotation must be added to the class' annotations list when generating them.
*
* Depending on whether the returned option is defined, it adds to `jclass` one of:
* (a) the ScalaSig marker attribute
* (indicating that a scala-signature-annotation aka pickle is present in this class); or
* (b) the Scala marker attribute
* (indicating that a scala-signature-annotation aka pickle is to be found in another file).
*
*
* @param jclassName The class file that is being readied.
* @param sym The symbol for which the signature has been entered in the symData map.
* This is different than the symbol
* that is being generated in the case of a mirror class.
* @return An option that is:
* - defined and contains an AnnotationInfo of the ScalaSignature type,
* instantiated with the pickle signature for sym.
* - empty if the jclass/sym pair must not contain a pickle.
*
* must-single-thread
*/
def getAnnotPickle(jclassName: String, sym: Symbol): Option[AnnotationInfo] = {
currentRun.symData get sym match {
case Some(pickle) if !nme.isModuleName(newTermName(jclassName)) =>
val scalaAnnot = {
val sigBytes = ScalaSigBytes(pickle.bytes.take(pickle.writeIndex))
AnnotationInfo(sigBytes.sigAnnot, Nil, (nme.bytes, sigBytes) :: Nil)
}
pickledBytes += pickle.writeIndex
currentRun.symData -= sym
currentRun.symData -= sym.companionSymbol
Some(scalaAnnot)
case _ =>
None
}
}
} // end of trait BCPickles
trait BCInnerClassGen {
def debugLevel = settings.debuginfo.indexOfChoice
val emitSource = debugLevel >= 1
val emitLines = debugLevel >= 2
val emitVars = debugLevel >= 3
/*
* Contains class-symbols that:
* (a) are known to denote inner classes
* (b) are mentioned somewhere in the class being generated.
*
* In other words, the lifetime of `innerClassBufferASM` is associated to "the class being generated".
*/
val innerClassBufferASM = mutable.Set.empty[BType]
/*
* Tracks (if needed) the inner class given by `sym`.
*
* must-single-thread
*/
final def internalName(sym: Symbol): String = { asmClassType(sym).getInternalName }
/*
* Tracks (if needed) the inner class given by `sym`.
*
* must-single-thread
*/
final def asmClassType(sym: Symbol): BType = {
assert(
hasInternalName(sym),
{
val msg0 = if (sym.isAbstractType) "An AbstractTypeSymbol (SI-7122) " else "A symbol ";
msg0 + s"has reached the bytecode emitter, for which no JVM-level internal name can be found: ${sym.fullName}"
}
)
val phantOpt = phantomTypeMap.get(sym)
if (phantOpt.isDefined) {
return phantOpt.get
}
val tracked = exemplar(sym)
val tk = tracked.c
if (tracked.isInnerClass) {
innerClassBufferASM += tk
}
tk
}
/*
* Returns the BType for the given type.
* Tracks (if needed) the inner class given by `t`.
*
* must-single-thread
*/
final def toTypeKind(t: Type): BType = {
/* Interfaces have to be handled delicately to avoid introducing spurious errors,
* but if we treat them all as AnyRef we lose too much information.
*/
def newReference(sym0: Symbol): BType = {
assert(!primitiveTypeMap.contains(sym0), "Use primitiveTypeMap instead.")
assert(sym0 != definitions.ArrayClass, "Use arrayOf() instead.")
if (sym0 == definitions.NullClass) return RT_NULL;
if (sym0 == definitions.NothingClass) return RT_NOTHING;
val sym = (
if (!sym0.isPackageClass) sym0
else sym0.info.member(nme.PACKAGE) match {
case NoSymbol => abort(s"SI-5604: Cannot use package as value: ${sym0.fullName}")
case s => abort(s"SI-5604: found package class where package object expected: $s")
}
)
// Can't call .toInterface (at this phase) or we trip an assertion.
// See PackratParser#grow for a method which fails with an apparent mismatch
// between "object PackratParsers$class" and "trait PackratParsers"
if (sym.isImplClass) {
// pos/spec-List.scala is the sole failure if we don't check for NoSymbol
val traitSym = sym.owner.info.decl(tpnme.interfaceName(sym.name))
if (traitSym != NoSymbol) {
// this tracks the inner class in innerClassBufferASM, if needed.
return asmClassType(traitSym)
}
}
assert(hasInternalName(sym), s"Invoked for a symbol lacking JVM internal name: ${sym.fullName}")
assert(!phantomTypeMap.contains(sym), "phantom types not supposed to reach here.")
val tracked = exemplar(sym)
val tk = tracked.c
if (tracked.isInnerClass) {
innerClassBufferASM += tk
}
tk
}
def primitiveOrRefType(sym: Symbol): BType = {
assert(sym != definitions.ArrayClass, "Use primitiveOrArrayOrRefType() instead.")
primitiveTypeMap.getOrElse(sym, newReference(sym))
}
def primitiveOrRefType2(sym: Symbol): BType = {
primitiveTypeMap.get(sym) match {
case Some(pt) => pt
case None =>
sym match {
case definitions.NullClass => RT_NULL
case definitions.NothingClass => RT_NOTHING
case _ if sym.isClass => newReference(sym)
case _ =>
assert(sym.isType, sym) // it must be compiling Array[a]
ObjectReference
}
}
}
import definitions.ArrayClass
// Call to .normalize fixes #3003 (follow type aliases). Otherwise, primitiveOrArrayOrRefType() would return ObjectReference.
t.normalize match {
case ThisType(sym) =>
if (sym == ArrayClass) ObjectReference
else phantomTypeMap.getOrElse(sym, exemplar(sym).c)
case SingleType(_, sym) => primitiveOrRefType(sym)
case _: ConstantType => toTypeKind(t.underlying)
case TypeRef(_, sym, args) =>
if (sym == ArrayClass) arrayOf(toTypeKind(args.head))
else primitiveOrRefType2(sym)
case ClassInfoType(_, _, sym) =>
assert(sym != ArrayClass, "ClassInfoType to ArrayClass!")
primitiveOrRefType(sym)
// !!! Iulian says types which make no sense after erasure should not reach here, which includes the ExistentialType, AnnotatedType, RefinedType.
case ExistentialType(_, t) => toTypeKind(t) // TODO shouldn't get here but the following does: akka-actor/src/main/scala/akka/util/WildcardTree.scala
case AnnotatedType(_, w) => toTypeKind(w) // TODO test/files/jvm/annotations.scala causes an AnnotatedType to reach here.
case RefinedType(parents, _) => parents map toTypeKind reduceLeft jvmWiseLUB
// For sure WildcardTypes shouldn't reach here either, but when debugging such situations this may come in handy.
// case WildcardType => REFERENCE(ObjectClass)
case norm => abort(
s"Unknown type: $t, $norm [${t.getClass}, ${norm.getClass}] TypeRef? ${t.isInstanceOf[TypeRef]}"
)
}
} // end of method toTypeKind()
/*
* must-single-thread
*/
def asmMethodType(msym: Symbol): BType = {
assert(msym.isMethod, s"not a method-symbol: $msym")
val resT: BType =
if (msym.isClassConstructor || msym.isConstructor) BType.VOID_TYPE
else toTypeKind(msym.tpe.resultType);
BType.getMethodType( resT, mkArray(msym.tpe.paramTypes map toTypeKind) )
}
/*
* Returns all direct member inner classes of `csym`,
* thus making sure they get entries in the InnerClasses JVM attribute
* even if otherwise not mentioned in the class being built.
*
* must-single-thread
*/
final def trackMemberClasses(csym: Symbol, lateClosuresBTs: List[BType]): List[BType] = {
val lateInnerClasses = exitingErasure {
for (sym <- List(csym, csym.linkedClassOfClass); memberc <- sym.info.decls.map(innerClassSymbolFor) if memberc.isClass)
yield memberc
}
// as a precaution, do the following outside the above `exitingErasure` otherwise funny internal names might be computed.
val result = for(memberc <- lateInnerClasses) yield {
val tracked = exemplar(memberc)
val memberCTK = tracked.c
assert(tracked.isInnerClass, s"saveInnerClassesFor() says this was no inner-class after all: ${memberc.fullName}")
memberCTK
}
exemplar(csym).directMemberClasses = result
result
}
/*
* Tracks (if needed) the inner class given by `t`.
*
* must-single-thread
*/
final def descriptor(t: Type): String = { toTypeKind(t).getDescriptor }
/*
* Tracks (if needed) the inner class given by `sym`.
*
* must-single-thread
*/
final def descriptor(sym: Symbol): String = { asmClassType(sym).getDescriptor }
} // end of trait BCInnerClassGen
trait BCAnnotGen extends BCInnerClassGen {
import genASM.{ubytesToCharArray, arrEncode}
/*
* can-multi-thread
*/
private def strEncode(sb: ScalaSigBytes): String = {
val ca = ubytesToCharArray(sb.sevenBitsMayBeZero)
new java.lang.String(ca)
// debug val bvA = new asm.ByteVector; bvA.putUTF8(s)
// debug val enc: Array[Byte] = scala.reflect.internal.pickling.ByteCodecs.encode(bytes)
// debug assert(enc(idx) == bvA.getByte(idx + 2))
// debug assert(bvA.getLength == enc.size + 2)
}
/*
* For arg a LiteralAnnotArg(constt) with const.tag in {ClazzTag, EnumTag}
* as well as for arg a NestedAnnotArg
* must-single-thread
* Otherwise it's safe to call from multiple threads.
*/
def emitArgument(av: asm.AnnotationVisitor,
name: String,
arg: ClassfileAnnotArg) {
(arg: @unchecked) match {
case LiteralAnnotArg(const) =>
if (const.isNonUnitAnyVal) { av.visit(name, const.value) }
else {
const.tag match {
case StringTag =>
assert(const.value != null, const) // TODO this invariant isn't documented in `case class Constant`
av.visit(name, const.stringValue) // `stringValue` special-cases null, but that execution path isn't exercised for a const with StringTag
case ClazzTag => av.visit(name, toTypeKind(const.typeValue).toASMType)
case EnumTag =>
val edesc = descriptor(const.tpe) // the class descriptor of the enumeration class.
val evalue = const.symbolValue.name.toString // value the actual enumeration value.
av.visitEnum(name, edesc, evalue)
}
}
case sb @ ScalaSigBytes(bytes) =>
// see http://www.scala-lang.org/sid/10 (Storage of pickled Scala signatures in class files)
// also JVMS Sec. 4.7.16.1 The element_value structure and JVMS Sec. 4.4.7 The CONSTANT_Utf8_info Structure.
if (sb.fitsInOneString) {
av.visit(name, strEncode(sb))
} else {
val arrAnnotV: asm.AnnotationVisitor = av.visitArray(name)
for(arg <- genASM.arrEncode(sb)) { arrAnnotV.visit(name, arg) }
arrAnnotV.visitEnd()
} // for the lazy val in ScalaSigBytes to be GC'ed, the invoker of emitAnnotations() should hold the ScalaSigBytes in a method-local var that doesn't escape.
case ArrayAnnotArg(args) =>
val arrAnnotV: asm.AnnotationVisitor = av.visitArray(name)
for(arg <- args) { emitArgument(arrAnnotV, null, arg) }
arrAnnotV.visitEnd()
case NestedAnnotArg(annInfo) =>
val AnnotationInfo(typ, args, assocs) = annInfo
assert(args.isEmpty, args)
val desc = descriptor(typ) // the class descriptor of the nested annotation class
val nestedVisitor = av.visitAnnotation(name, desc)
emitAssocs(nestedVisitor, assocs)
}
}
/* Whether an annotation should be emitted as a Java annotation
* .initialize: if 'annot' is read from pickle, atp might be un-initialized
*
* must-single-thread
*/
private def shouldEmitAnnotation(annot: AnnotationInfo) =
annot.symbol.initialize.isJavaDefined &&
annot.matches(definitions.ClassfileAnnotationClass) &&
annot.args.isEmpty &&
!annot.matches(definitions.DeprecatedAttr)
/*
* In general,
* must-single-thread
* but not necessarily always.
*/
def emitAssocs(av: asm.AnnotationVisitor, assocs: List[(Name, ClassfileAnnotArg)]) {
for ((name, value) <- assocs) {
emitArgument(av, name.toString(), value)
}
av.visitEnd()
}
/*
* must-single-thread
*/
def emitAnnotations(cw: asm.ClassVisitor, annotations: List[AnnotationInfo]) {
for(annot <- annotations; if shouldEmitAnnotation(annot)) {
val AnnotationInfo(typ, args, assocs) = annot
assert(args.isEmpty, args)
val av = cw.visitAnnotation(descriptor(typ), true)
emitAssocs(av, assocs)
}
}
/*
* must-single-thread
*/
def emitAnnotations(mw: asm.MethodVisitor, annotations: List[AnnotationInfo]) {
for(annot <- annotations; if shouldEmitAnnotation(annot)) {
val AnnotationInfo(typ, args, assocs) = annot
assert(args.isEmpty, args)
val av = mw.visitAnnotation(descriptor(typ), true)
emitAssocs(av, assocs)
}
}
/*
* must-single-thread
*/
def emitAnnotations(fw: asm.FieldVisitor, annotations: List[AnnotationInfo]) {
for(annot <- annotations; if shouldEmitAnnotation(annot)) {
val AnnotationInfo(typ, args, assocs) = annot
assert(args.isEmpty, args)
val av = fw.visitAnnotation(descriptor(typ), true)
emitAssocs(av, assocs)
}
}
/*
* must-single-thread
*/
def emitParamAnnotations(jmethod: asm.MethodVisitor, pannotss: List[List[AnnotationInfo]]) {
val annotationss = pannotss map (_ filter shouldEmitAnnotation)
if (annotationss forall (_.isEmpty)) return
for ((annots, idx) <- annotationss.zipWithIndex;
annot <- annots) {
val AnnotationInfo(typ, args, assocs) = annot
assert(args.isEmpty, args)
val pannVisitor: asm.AnnotationVisitor = jmethod.visitParameterAnnotation(idx, descriptor(typ), true)
emitAssocs(pannVisitor, assocs)
}
}
} // end of trait BCAnnotGen
trait BCJGenSigGen {
def getCurrentCUnit(): CompilationUnit
/* @return
* - `null` if no Java signature is to be added (`null` is what ASM expects in these cases).
* - otherwise the signature in question
*
* must-single-thread
*/
def getGenericSignature(sym: Symbol, owner: Symbol): String = genASM.getGenericSignature(sym, owner, getCurrentCUnit())
} // end of trait BCJGenSigGen
trait BCForwardersGen extends BCAnnotGen with BCJGenSigGen {
// -----------------------------------------------------------------------------------------
// Static forwarders (related to mirror classes but also present in
// a plain class lacking companion module, for details see `isCandidateForForwarders`).
// -----------------------------------------------------------------------------------------
val ExcludedForwarderFlags = genASM.ExcludedForwarderFlags
/* Adds a @remote annotation, actual use unknown.
*
* Invoked from genMethod() and addForwarder().
*
* must-single-thread
*/
def addRemoteExceptionAnnot(isRemoteClass: Boolean, isJMethodPublic: Boolean, meth: Symbol) {
val needsAnnotation = (
( isRemoteClass ||
isRemote(meth) && isJMethodPublic
) && !(meth.throwsAnnotations contains definitions.RemoteExceptionClass)
)
if (needsAnnotation) {
val c = Constant(definitions.RemoteExceptionClass.tpe)
val arg = Literal(c) setType c.tpe
meth.addAnnotation(appliedType(definitions.ThrowsClass, c.tpe), arg)
}
}
/* Add a forwarder for method m. Used only from addForwarders().
*
* must-single-thread
*/
private def addForwarder(isRemoteClass: Boolean, jclass: asm.ClassVisitor, module: Symbol, m: Symbol) {
val moduleName = internalName(module)
val methodInfo = module.thisType.memberInfo(m)
val paramJavaTypes: List[BType] = methodInfo.paramTypes map toTypeKind
// val paramNames = 0 until paramJavaTypes.length map ("x_" + _)
/* Forwarders must not be marked final,
* as the JVM will not allow redefinition of a final static method,
* and we don't know what classes might be subclassing the companion class. See SI-4827.
*/
// TODO: evaluate the other flags we might be dropping on the floor here.
// TODO: ACC_SYNTHETIC ?
val flags = PublicStatic | (
if (m.isVarargsMethod) asm.Opcodes.ACC_VARARGS else 0
)
// TODO needed? for(ann <- m.annotations) { ann.symbol.initialize }
val jgensig = genASM.staticForwarderGenericSignature(m, module, getCurrentCUnit())
addRemoteExceptionAnnot(isRemoteClass, hasPublicBitSet(flags), m)
val (throws, others) = m.annotations partition (_.symbol == definitions.ThrowsClass)
val thrownExceptions: List[String] = getExceptions(throws)
val jReturnType = toTypeKind(methodInfo.resultType)
val mdesc = BType.getMethodType(jReturnType, mkArray(paramJavaTypes)).getDescriptor
val mirrorMethodName = m.javaSimpleName.toString
val mirrorMethod: asm.MethodVisitor = jclass.visitMethod(
flags,
mirrorMethodName,
mdesc,
jgensig,
mkArray(thrownExceptions)
)
emitAnnotations(mirrorMethod, others)
emitParamAnnotations(mirrorMethod, m.info.params.map(_.annotations))
mirrorMethod.visitCode()
mirrorMethod.visitFieldInsn(asm.Opcodes.GETSTATIC, moduleName, strMODULE_INSTANCE_FIELD, descriptor(module))
var index = 0
for(jparamType <- paramJavaTypes) {
mirrorMethod.visitVarInsn(jparamType.getOpcode(asm.Opcodes.ILOAD), index)
assert(jparamType.sort != BType.METHOD, jparamType)
index += jparamType.getSize
}
mirrorMethod.visitMethodInsn(asm.Opcodes.INVOKEVIRTUAL, moduleName, mirrorMethodName, asmMethodType(m).getDescriptor)
mirrorMethod.visitInsn(jReturnType.getOpcode(asm.Opcodes.IRETURN))
mirrorMethod.visitMaxs(0, 0) // just to follow protocol, dummy arguments
mirrorMethod.visitEnd()
}
/* Add forwarders for all methods defined in `module` that don't conflict
* with methods in the companion class of `module`. A conflict arises when
* a method with the same name is defined both in a class and its companion object:
* method signature is not taken into account.
*
* must-single-thread
*/
def addForwarders(isRemoteClass: Boolean, jclass: asm.ClassVisitor, jclassName: String, moduleClass: Symbol) {
assert(moduleClass.isModuleClass, moduleClass)
debuglog(s"Dumping mirror class for object: $moduleClass")
val linkedClass = moduleClass.companionClass
lazy val conflictingNames: Set[Name] = {
(linkedClass.info.members collect { case sym if sym.name.isTermName => sym.name }).toSet
}
debuglog(s"Potentially conflicting names for forwarders: $conflictingNames")
for (m <- moduleClass.info.membersBasedOnFlags(ExcludedForwarderFlags, symtab.Flags.METHOD)) {
if (m.isType || m.isDeferred || (m.owner eq definitions.ObjectClass) || m.isConstructor)
debuglog(s"No forwarder for '$m' from $jclassName to '$moduleClass'")
else if (conflictingNames(m.name))
log(s"No forwarder for $m due to conflict with ${linkedClass.info.member(m.name)}")
else if (m.hasAccessBoundary)
log(s"No forwarder for non-public member $m")
else {
log(s"Adding static forwarder for '$m' from $jclassName to '$moduleClass'")
addForwarder(isRemoteClass, jclass, moduleClass, m)
}
}
}
/*
* Quoting from JVMS 4.7.5 The Exceptions Attribute
* "The Exceptions attribute indicates which checked exceptions a method may throw.
* There may be at most one Exceptions attribute in each method_info structure."
*
* The contents of that attribute are determined by the `String[] exceptions` argument to ASM's ClassVisitor.visitMethod()
* This method returns such list of internal names.
*
* must-single-thread
*/
def getExceptions(excs: List[AnnotationInfo]): List[String] = {
for (ThrownException(exc) <- excs.distinct)
yield internalName(exc)
}
} // end of trait BCForwardersGen
trait BCClassGen extends BCInnerClassGen {
// Used as threshold above which a tableswitch bytecode instruction is preferred over a lookupswitch.
// There's a space tradeoff between these multi-branch instructions (details in the JVM spec).
// The particular value in use for `MIN_SWITCH_DENSITY` reflects a heuristic.
val MIN_SWITCH_DENSITY = 0.7
/*
* Add public static final field serialVersionUID with value `id`
*
* can-multi-thread
*/
def addSerialVUID(id: Long, jclass: asm.ClassVisitor) {
// add static serialVersionUID field if `clasz` annotated with `@SerialVersionUID(uid: Long)`
jclass.visitField(
PublicStaticFinal,
"serialVersionUID",
"J",
null, // no java-generic-signature
new java.lang.Long(id)
).visitEnd()
}
/*
* @param owner internal name of the enclosing class of the class.
*
* @param name the name of the method that contains the class.
* @param methodType the method that contains the class.
*/
case class EnclMethodEntry(owner: String, name: String, methodType: BType)
/*
* @return null if the current class is not internal to a method
*
* Quoting from JVMS 4.7.7 The EnclosingMethod Attribute
* A class must have an EnclosingMethod attribute if and only if it is a local class or an anonymous class.
* A class may have no more than one EnclosingMethod attribute.
*
* must-single-thread
*/
def getEnclosingMethodAttribute(clazz: Symbol): EnclMethodEntry = { // JVMS 4.7.7
def newEEE(eClass: Symbol, m: Symbol) = {
EnclMethodEntry(
internalName(eClass),
m.javaSimpleName.toString,
asmMethodType(m)
)
}
var res: EnclMethodEntry = null
val sym = clazz.originalEnclosingMethod
if (sym.isMethod) {
debuglog(s"enclosing method for $clazz is $sym (in ${sym.enclClass})")
res = newEEE(sym.enclClass, sym)
} else if (clazz.isAnonymousClass) {
val enclClass = clazz.rawowner
assert(enclClass.isClass, enclClass)
val sym = enclClass.primaryConstructor
if (sym == NoSymbol) {
log(s"Ran out of room looking for an enclosing method for $clazz: no constructor here: $enclClass.")
} else {
debuglog(s"enclosing method for $clazz is $sym (in $enclClass)")
res = newEEE(enclClass, sym)
}
}
res
}
} // end of trait BCClassGen
/* basic functionality for class file building of plain, mirror, and beaninfo classes. */
abstract class JBuilder extends BCInnerClassGen {
} // end of class JBuilder
/* functionality for building plain and mirror classes */
abstract class JCommonBuilder
extends JBuilder
with BCAnnotGen
with BCForwardersGen
with BCPickles { }
/* builder of mirror classes */
class JMirrorBuilder extends JCommonBuilder {
private var cunit: CompilationUnit = _
def getCurrentCUnit(): CompilationUnit = cunit;
/* Generate a mirror class for a top-level module. A mirror class is a class
* containing only static methods that forward to the corresponding method
* on the MODULE instance of the given Scala object. It will only be
* generated if there is no companion class: if there is, an attempt will
* instead be made to add the forwarder methods to the companion class.
*
* must-single-thread
*/
def genMirrorClass(modsym: Symbol, cunit: CompilationUnit): asm.tree.ClassNode = {
assert(modsym.companionClass == NoSymbol, modsym)
innerClassBufferASM.clear()
this.cunit = cunit
val moduleName = internalName(modsym) // + "$"
val mirrorName = moduleName.substring(0, moduleName.length() - 1)
val flags = (asm.Opcodes.ACC_SUPER | asm.Opcodes.ACC_PUBLIC | asm.Opcodes.ACC_FINAL)
val mirrorClass = new asm.tree.ClassNode
mirrorClass.visit(
classfileVersion,
flags,
mirrorName,
null /* no java-generic-signature */,
JAVA_LANG_OBJECT.getInternalName,
EMPTY_STRING_ARRAY
)
if (emitSource) {
mirrorClass.visitSource("" + cunit.source,
null /* SourceDebugExtension */)
}
val ssa = getAnnotPickle(mirrorName, modsym.companionSymbol)
mirrorClass.visitAttribute(if (ssa.isDefined) pickleMarkerLocal else pickleMarkerForeign)
emitAnnotations(mirrorClass, modsym.annotations ++ ssa)
addForwarders(isRemote(modsym), mirrorClass, mirrorName, modsym)
innerClassBufferASM ++= trackMemberClasses(modsym, Nil /* TODO what about Late-Closure-Classes */ )
addInnerClassesASM(mirrorClass, innerClassBufferASM.toList)
mirrorClass.visitEnd()
("" + modsym.name) // this side-effect is necessary, really.
mirrorClass
}
} // end of class JMirrorBuilder
/* builder of bean info classes */
class JBeanInfoBuilder extends JBuilder {
/*
* Generate a bean info class that describes the given class.
*
* @author Ross Judson (ross.judson@soletta.com)
*
* must-single-thread
*/
def genBeanInfoClass(cls: Symbol, cunit: CompilationUnit, fieldSymbols: List[Symbol], methodSymbols: List[Symbol]): asm.tree.ClassNode = {
def javaSimpleName(s: Symbol): String = { s.javaSimpleName.toString }
innerClassBufferASM.clear()
val flags = mkFlags(
javaFlags(cls),
if (isDeprecated(cls)) asm.Opcodes.ACC_DEPRECATED else 0 // ASM pseudo access flag
)
val beanInfoName = (internalName(cls) + "BeanInfo")
val beanInfoClass = new asm.tree.ClassNode
beanInfoClass.visit(
classfileVersion,
flags,
beanInfoName,
null, // no java-generic-signature
"scala/beans/ScalaBeanInfo",
EMPTY_STRING_ARRAY
)
beanInfoClass.visitSource(
cunit.source.toString,
null /* SourceDebugExtension */
)
var fieldList = List[String]()
for (f <- fieldSymbols if f.hasGetter;
g = f.getter(cls);
s = f.setter(cls);
if g.isPublic && !(f.name startsWith "$")
) {
// inserting $outer breaks the bean
fieldList = javaSimpleName(f) :: javaSimpleName(g) :: (if (s != NoSymbol) javaSimpleName(s) else null) :: fieldList
}
val methodList: List[String] =
for (m <- methodSymbols
if !m.isConstructor &&
m.isPublic &&
!(m.name startsWith "$") &&
!m.isGetter &&
!m.isSetter)
yield javaSimpleName(m)
val constructor = beanInfoClass.visitMethod(
asm.Opcodes.ACC_PUBLIC,
INSTANCE_CONSTRUCTOR_NAME,
"()V",
null, // no java-generic-signature
EMPTY_STRING_ARRAY // no throwable exceptions
)
val stringArrayJType: BType = arrayOf(JAVA_LANG_STRING)
val conJType: BType =
BType.getMethodType(
BType.VOID_TYPE,
Array(exemplar(definitions.ClassClass).c, stringArrayJType, stringArrayJType)
)
def push(lst: List[String]) {
var fi = 0
for (f <- lst) {
constructor.visitInsn(asm.Opcodes.DUP)
constructor.visitLdcInsn(new java.lang.Integer(fi))
if (f == null) { constructor.visitInsn(asm.Opcodes.ACONST_NULL) }
else { constructor.visitLdcInsn(f) }
constructor.visitInsn(JAVA_LANG_STRING.getOpcode(asm.Opcodes.IASTORE))
fi += 1
}
}
constructor.visitCode()
constructor.visitVarInsn(asm.Opcodes.ALOAD, 0)
// push the class
constructor.visitLdcInsn(exemplar(cls).c)
// push the string array of field information
constructor.visitLdcInsn(new java.lang.Integer(fieldList.length))
constructor.visitTypeInsn(asm.Opcodes.ANEWARRAY, JAVA_LANG_STRING.getInternalName)
push(fieldList)
// push the string array of method information
constructor.visitLdcInsn(new java.lang.Integer(methodList.length))
constructor.visitTypeInsn(asm.Opcodes.ANEWARRAY, JAVA_LANG_STRING.getInternalName)
push(methodList)
// invoke the superclass constructor, which will do the
// necessary java reflection and create Method objects.
constructor.visitMethodInsn(asm.Opcodes.INVOKESPECIAL, "scala/beans/ScalaBeanInfo", INSTANCE_CONSTRUCTOR_NAME, conJType.getDescriptor)
constructor.visitInsn(asm.Opcodes.RETURN)
constructor.visitMaxs(0, 0) // just to follow protocol, dummy arguments
constructor.visitEnd()
innerClassBufferASM ++= trackMemberClasses(cls, Nil /* TODO what about Late-Closure-Classes */ )
addInnerClassesASM(beanInfoClass, innerClassBufferASM.toList)
beanInfoClass.visitEnd()
beanInfoClass
}
} // end of class JBeanInfoBuilder
trait JAndroidBuilder {
self: BCInnerClassGen =>
/* From the reference documentation of the Android SDK:
* The `Parcelable` interface identifies classes whose instances can be written to and restored from a `Parcel`.
* Classes implementing the `Parcelable` interface must also have a static field called `CREATOR`,
* which is an object implementing the `Parcelable.Creator` interface.
*/
val androidFieldName = newTermName("CREATOR")
/*
* must-single-thread
*/
def isAndroidParcelableClass(sym: Symbol) =
(AndroidParcelableInterface != NoSymbol) &&
(sym.parentSymbols contains AndroidParcelableInterface)
/*
* must-single-thread
*/
def legacyAddCreatorCode(clinit: asm.MethodVisitor, cnode: asm.tree.ClassNode, thisName: String) {
// this tracks the inner class in innerClassBufferASM, if needed.
val androidCreatorType = asmClassType(AndroidCreatorClass)
val tdesc_creator = androidCreatorType.getDescriptor
cnode.visitField(
PublicStaticFinal,
"CREATOR",
tdesc_creator,
null, // no java-generic-signature
null // no initial value
).visitEnd()
val moduleName = (thisName + "$")
// GETSTATIC `moduleName`.MODULE$ : `moduleName`;
clinit.visitFieldInsn(
asm.Opcodes.GETSTATIC,
moduleName,
strMODULE_INSTANCE_FIELD,
"L" + moduleName + ";"
)
// INVOKEVIRTUAL `moduleName`.CREATOR() : android.os.Parcelable$Creator;
val bt = BType.getMethodType(androidCreatorType, Array.empty[BType])
clinit.visitMethodInsn(
asm.Opcodes.INVOKEVIRTUAL,
moduleName,
"CREATOR",
bt.getDescriptor
)
// PUTSTATIC `thisName`.CREATOR;
clinit.visitFieldInsn(
asm.Opcodes.PUTSTATIC,
thisName,
"CREATOR",
tdesc_creator
)
}
} // end of trait JAndroidBuilder
}
|