forked from swiftlang/swift
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathGenMeta.cpp
5784 lines (4892 loc) · 223 KB
/
GenMeta.cpp
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
//===--- GenMeta.cpp - IR generation for metadata constructs --------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file implements IR generation for type metadata constructs.
//
//===----------------------------------------------------------------------===//
#include "swift/AST/ArchetypeBuilder.h"
#include "swift/AST/ASTContext.h"
#include "swift/AST/CanTypeVisitor.h"
#include "swift/AST/Decl.h"
#include "swift/AST/IRGenOptions.h"
#include "swift/AST/Mangle.h"
#include "swift/AST/Substitution.h"
#include "swift/AST/Types.h"
#include "swift/SIL/FormalLinkage.h"
#include "swift/SIL/SILModule.h"
#include "swift/SIL/TypeLowering.h"
#include "swift/Runtime/Metadata.h"
#include "swift/ABI/MetadataValues.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Module.h"
#include "llvm/ADT/SmallString.h"
#include "Address.h"
#include "Callee.h"
#include "ClassMetadataLayout.h"
#include "ConstantBuilder.h"
#include "FixedTypeInfo.h"
#include "GenClass.h"
#include "GenPoly.h"
#include "GenValueWitness.h"
#include "GenArchetype.h"
#include "GenStruct.h"
#include "HeapTypeInfo.h"
#include "IRGenModule.h"
#include "IRGenDebugInfo.h"
#include "Linking.h"
#include "ScalarTypeInfo.h"
#include "StructMetadataLayout.h"
#include "StructLayout.h"
#include "EnumMetadataLayout.h"
#include "GenMeta.h"
using namespace swift;
using namespace irgen;
static llvm::Value *emitLoadOfObjCHeapMetadataRef(IRGenFunction &IGF,
llvm::Value *object);
static Address emitAddressOfMetadataSlotAtIndex(IRGenFunction &IGF,
llvm::Value *metadata,
int index,
llvm::Type *objectTy) {
// Require the metadata to be some type that we recognize as a
// metadata pointer.
assert(metadata->getType() == IGF.IGM.TypeMetadataPtrTy);
// We require objectType to be a pointer type so that the GEP will
// scale by the right amount. We could load an arbitrary type using
// some extra bitcasting.
assert(IGF.IGM.DataLayout.getTypeStoreSize(objectTy) ==
IGF.IGM.DataLayout.getTypeStoreSize(IGF.IGM.SizeTy));
// Cast to T*.
auto objectPtrTy = objectTy->getPointerTo();
auto metadataWords = IGF.Builder.CreateBitCast(metadata, objectPtrTy);
auto indexV = llvm::ConstantInt::getSigned(IGF.IGM.SizeTy, index);
// GEP to the slot.
Address slot(IGF.Builder.CreateInBoundsGEP(metadataWords, indexV),
IGF.IGM.getPointerAlignment());
return slot;
}
/// Emit a load from the given metadata at a constant index.
static llvm::LoadInst *emitLoadFromMetadataAtIndex(IRGenFunction &IGF,
llvm::Value *metadata,
int index,
llvm::Type *objectTy,
const llvm::Twine &suffix = "") {
Address slot =
emitAddressOfMetadataSlotAtIndex(IGF, metadata, index, objectTy);
// Load.
return IGF.Builder.CreateLoad(slot, metadata->getName() + suffix);
}
static int getClassParentIndex(IRGenModule &IGM, ClassDecl *classDecl);
/// Produce a constant to place in a metatype's isa field
/// corresponding to the given metadata kind.
static llvm::ConstantInt *getMetadataKind(IRGenModule &IGM,
MetadataKind kind) {
return llvm::ConstantInt::get(IGM.MetadataKindTy, uint8_t(kind));
}
static Address createPointerSizedGEP(IRGenFunction &IGF,
Address base,
Size offset) {
return IGF.Builder.CreateConstArrayGEP(base,
IGF.IGM.getOffsetInWords(offset),
offset);
}
// FIXME: willBeRelativelyAddressed is only needed to work around an ld64 bug
// resolving relative references to coalesceable symbols.
// It should be removed when fixed. rdar://problem/22674524
static llvm::Constant *getMangledTypeName(IRGenModule &IGM, CanType type,
bool willBeRelativelyAddressed = false) {
auto name = LinkEntity::forTypeMangling(type);
llvm::SmallString<32> mangling;
name.mangle(mangling);
return IGM.getAddrOfGlobalString(mangling, willBeRelativelyAddressed);
}
llvm::Value *irgen::emitObjCMetadataRefForMetadata(IRGenFunction &IGF,
llvm::Value *classPtr) {
classPtr = IGF.Builder.CreateBitCast(classPtr, IGF.IGM.ObjCClassPtrTy);
// Fetch the metadata for that class.
auto call = IGF.Builder.CreateCall(IGF.IGM.getGetObjCClassMetadataFn(),
classPtr);
call->setDoesNotThrow();
call->setDoesNotAccessMemory();
return call;
}
/// Emit a reference to the Swift metadata for an Objective-C class.
static llvm::Value *emitObjCMetadataRef(IRGenFunction &IGF,
ClassDecl *theClass) {
// Derive a pointer to the Objective-C class.
auto classPtr = emitObjCHeapMetadataRef(IGF, theClass);
return emitObjCMetadataRefForMetadata(IGF, classPtr);
}
namespace {
/// A structure for collecting generic arguments for emitting a
/// nominal metadata reference. The structure produced here is
/// consumed by swift_getGenericMetadata() and must correspond to
/// the fill operations that the compiler emits for the bound decl.
///
/// FIXME: Rework to use GenericSignature instead of AllArchetypes
struct GenericArguments {
/// The values to use to initialize the arguments structure.
SmallVector<llvm::Value *, 8> Values;
SmallVector<llvm::Type *, 8> Types;
static unsigned getNumGenericArguments(IRGenModule &IGM,
NominalTypeDecl *nominal) {
GenericTypeRequirements requirements(IGM, nominal);
return unsigned(requirements.hasParentType())
+ requirements.getNumTypeRequirements();
}
void collectTypes(IRGenModule &IGM, NominalTypeDecl *nominal) {
GenericTypeRequirements requirements(IGM, nominal);
collectTypes(IGM, requirements);
}
void collectTypes(IRGenModule &IGM,
const GenericTypeRequirements &requirements) {
if (requirements.hasParentType()) {
Types.push_back(IGM.TypeMetadataPtrTy);
}
for (auto &requirement : requirements.getRequirements()) {
if (requirement.Protocol) {
Types.push_back(IGM.WitnessTablePtrTy);
} else {
Types.push_back(IGM.TypeMetadataPtrTy);
}
}
}
void collect(IRGenFunction &IGF, CanType type) {
NominalTypeDecl *decl;
CanType parentType;
if (auto nominalType = dyn_cast<NominalType>(type)) {
decl = nominalType->getDecl();
parentType = nominalType.getParent();
} else {
auto boundType = cast<BoundGenericType>(type);
decl = boundType->getDecl();
parentType = boundType.getParent();
}
GenericTypeRequirements requirements(IGF.IGM, decl);
if (requirements.hasParentType()) {
Values.push_back(IGF.emitTypeMetadataRef(parentType));
}
auto subs =
type->gatherAllSubstitutions(IGF.IGM.getSwiftModule(), nullptr);
requirements.enumerateFulfillments(IGF.IGM, subs,
[&](unsigned reqtIndex, CanType type,
Optional<ProtocolConformanceRef> conf) {
if (conf) {
Values.push_back(emitWitnessTableRef(IGF, type, *conf));
} else {
Values.push_back(IGF.emitTypeMetadataRef(type));
}
});
collectTypes(IGF.IGM, decl);
assert(Types.size() == Values.size());
}
};
}
/// Given an array of polymorphic arguments as might be set up by
/// GenericArguments, bind the polymorphic parameters.
static void emitPolymorphicParametersFromArray(IRGenFunction &IGF,
NominalTypeDecl *typeDecl,
Address array) {
GenericTypeRequirements requirements(IGF.IGM, typeDecl);
array = IGF.Builder.CreateElementBitCast(array, IGF.IGM.TypeMetadataPtrTy);
auto getInContext = [&](CanType type) -> CanType {
return ArchetypeBuilder::mapTypeIntoContext(typeDecl, type)
->getCanonicalType();
};
// If we have a parent type, it's the first parameter.
if (requirements.hasParentType()) {
auto parentType = getInContext(requirements.getParentType());
llvm::Value *parentMetadata = IGF.Builder.CreateLoad(array);
array = IGF.Builder.CreateConstArrayGEP(array, 1, IGF.IGM.getPointerSize());
IGF.bindLocalTypeDataFromTypeMetadata(parentType, IsExact, parentMetadata);
}
// Okay, bind everything else from the context.
requirements.bindFromBuffer(IGF, array, getInContext);
}
static bool isTypeErasedGenericClass(NominalTypeDecl *ntd) {
// ObjC classes are type erased.
// TODO: Unless they have magic methods...
if (auto clas = dyn_cast<ClassDecl>(ntd))
return clas->hasClangNode() && clas->isGenericContext();
return false;
}
static bool isTypeErasedGenericClassType(CanType type) {
if (auto nom = type->getAnyNominal())
return isTypeErasedGenericClass(nom);
return false;
}
// Get the type that exists at runtime to represent a compile-time type.
CanType
irgen::getRuntimeReifiedType(IRGenModule &IGM, CanType type) {
return CanType(type.transform([&](Type t) -> Type {
if (isTypeErasedGenericClassType(CanType(t))) {
return t->getAnyNominal()->getDeclaredType()->getCanonicalType();
}
return t;
}));
}
/// Attempts to return a constant heap metadata reference for a
/// class type. This is generally only valid for specific kinds of
/// ObjC reference, like superclasses or category references.
llvm::Constant *irgen::tryEmitConstantHeapMetadataRef(IRGenModule &IGM,
CanType type,
bool allowDynamicUninitialized) {
auto theDecl = type->getClassOrBoundGenericClass();
assert(theDecl && "emitting constant heap metadata ref for non-class type?");
// If the class must not require dynamic initialization --- e.g. if it
// is a super reference --- then respect everything that might impose that.
if (!allowDynamicUninitialized) {
if (doesClassMetadataRequireDynamicInitialization(IGM, theDecl))
return nullptr;
// Otherwise, just respect genericity.
} else if (theDecl->isGenericContext() && !isTypeErasedGenericClass(theDecl)){
return nullptr;
}
// For imported classes, use the ObjC class symbol.
// This incidentally cannot coincide with most of the awkward cases, like
// having parent metadata.
if (!hasKnownSwiftMetadata(IGM, theDecl))
return IGM.getAddrOfObjCClass(theDecl, NotForDefinition);
return IGM.getAddrOfTypeMetadata(type, false);
}
/// Attempts to return a constant type metadata reference for a
/// nominal type.
ConstantReference
irgen::tryEmitConstantTypeMetadataRef(IRGenModule &IGM, CanType type,
SymbolReferenceKind refKind) {
if (!isTypeMetadataAccessTrivial(IGM, type))
return ConstantReference();
return IGM.getAddrOfTypeMetadata(type, false, refKind);
}
/// Emit a reference to an ObjC class. In general, the only things
/// you're allowed to do with the address of an ObjC class symbol are
/// (1) send ObjC messages to it (in which case the message will be
/// forwarded to the real class, if one exists) or (2) put it in
/// various data sections where the ObjC runtime will properly arrange
/// things. Therefore, we must typically force the initialization of
/// a class when emitting a reference to it.
llvm::Value *irgen::emitObjCHeapMetadataRef(IRGenFunction &IGF,
ClassDecl *theClass,
bool allowUninitialized) {
// If the class is visible only through the Objective-C runtime, form the
// appropriate runtime call.
if (theClass->getForeignClassKind() == ClassDecl::ForeignKind::RuntimeOnly) {
SmallString<64> scratch;
auto className =
IGF.IGM.getAddrOfGlobalString(theClass->getObjCRuntimeName(scratch));
return IGF.Builder.CreateCall(IGF.IGM.getLookUpClassFn(), className);
}
assert(!theClass->isForeign());
Address classRef = IGF.IGM.getAddrOfObjCClassRef(theClass);
auto classObject = IGF.Builder.CreateLoad(classRef);
if (allowUninitialized) return classObject;
// TODO: memoize this the same way that we memoize Swift type metadata?
return IGF.Builder.CreateCall(IGF.IGM.getGetInitializedObjCClassFn(),
classObject);
}
/// Emit a reference to the type metadata for a foreign type.
static llvm::Value *emitForeignTypeMetadataRef(IRGenFunction &IGF,
CanType type) {
llvm::Value *candidate = IGF.IGM.getAddrOfForeignTypeMetadataCandidate(type);
auto call = IGF.Builder.CreateCall(IGF.IGM.getGetForeignTypeMetadataFn(),
candidate);
call->addAttribute(llvm::AttributeSet::FunctionIndex,
llvm::Attribute::NoUnwind);
call->addAttribute(llvm::AttributeSet::FunctionIndex,
llvm::Attribute::ReadNone);
return call;
}
/// Returns a metadata reference for a nominal type.
///
/// This is only valid in a couple of special cases:
/// 1) The nominal type is generic, in which case we emit a call to the
/// generic metadata accessor function, which must be defined separately.
/// 2) The nominal type is a value type with a fixed size from this
/// resilience domain, in which case we can reference the constant
/// metadata directly.
///
/// In any other case, a metadata accessor should be called instead.
static llvm::Value *emitNominalMetadataRef(IRGenFunction &IGF,
NominalTypeDecl *theDecl,
CanType theType) {
assert(!isa<ProtocolDecl>(theDecl));
if (!theDecl->isGenericContext()) {
assert(!IGF.IGM.isResilient(theDecl, ResilienceExpansion::Maximal));
// TODO: If Obj-C interop is off, we can relax this to allow referencing
// class metadata too.
assert(isa<StructDecl>(theDecl) || isa<EnumDecl>(theDecl));
return IGF.IGM.getAddrOfTypeMetadata(theType, false);
}
// We are applying generic parameters to a generic type.
assert(theType->isSpecialized() &&
theType->getAnyNominal() == theDecl);
// Check to see if we've maybe got a local reference already.
if (auto cache = IGF.tryGetLocalTypeData(theType,
LocalTypeDataKind::forTypeMetadata()))
return cache;
// Grab the substitutions.
GenericArguments genericArgs;
genericArgs.collect(IGF, theType);
assert(genericArgs.Values.size() > 0 && "no generic args?!");
// Call the generic metadata accessor function.
llvm::Function *accessor =
IGF.IGM.getAddrOfGenericTypeMetadataAccessFunction(theDecl,
genericArgs.Types,
NotForDefinition);
auto result = IGF.Builder.CreateCall(accessor, genericArgs.Values);
result->setDoesNotThrow();
result->addAttribute(llvm::AttributeSet::FunctionIndex,
llvm::Attribute::ReadNone);
IGF.setScopedLocalTypeData(theType, LocalTypeDataKind::forTypeMetadata(),
result);
return result;
}
bool irgen::hasKnownSwiftMetadata(IRGenModule &IGM, CanType type) {
if (ClassDecl *theClass = type.getClassOrBoundGenericClass()) {
return hasKnownSwiftMetadata(IGM, theClass);
}
if (auto archetype = dyn_cast<ArchetypeType>(type)) {
if (auto superclass = archetype->getSuperclass()) {
return hasKnownSwiftMetadata(IGM, superclass->getCanonicalType());
}
}
// Class existentials, etc.
return false;
}
/// Is the given class known to have Swift-compatible metadata?
bool irgen::hasKnownSwiftMetadata(IRGenModule &IGM, ClassDecl *theClass) {
// For now, the fact that a declaration was not implemented in Swift
// is enough to conclusively force us into a slower path.
// Eventually we might have an attribute here or something based on
// the deployment target.
return theClass->hasKnownSwiftImplementation();
}
/// Is the given method known to be callable by vtable lookup?
bool irgen::hasKnownVTableEntry(IRGenModule &IGM,
AbstractFunctionDecl *theMethod) {
auto theClass = dyn_cast<ClassDecl>(theMethod->getDeclContext());
// Extension methods don't get vtable entries.
if (!theClass) {
return false;
}
return theClass->hasKnownSwiftImplementation();
}
/// Is it basically trivial to access the given metadata? If so, we don't
/// need a cache variable in its accessor.
bool irgen::isTypeMetadataAccessTrivial(IRGenModule &IGM, CanType type) {
assert(!type->hasArchetype());
// Value type metadata only requires dynamic initialization on first
// access if it contains a resilient type.
if (isa<StructType>(type) || isa<EnumType>(type)) {
auto nominalType = cast<NominalType>(type);
// Imported type metadata always requires an accessor.
if (nominalType->getDecl()->hasClangNode())
return false;
// Metadata with a non-trivial parent node always requires an accessor.
if (auto parent = nominalType.getParent())
if (!isTypeMetadataAccessTrivial(IGM, parent))
return false;
// Resiliently-sized metadata access always requires an accessor.
return (IGM.getTypeInfoForUnlowered(type).isFixedSize());
}
// The empty tuple type has a singleton metadata.
if (auto tuple = dyn_cast<TupleType>(type))
return tuple->getNumElements() == 0;
// The builtin types generally don't require metadata, but some of them
// have nodes in the runtime anyway.
if (isa<BuiltinType>(type))
return true;
// SIL box types are artificial, but for the purposes of dynamic layout,
// we use the NativeObject metadata.
if (isa<SILBoxType>(type))
return true;
// DynamicSelfType is actually local.
if (type->hasDynamicSelfType())
return true;
return false;
}
static bool hasRequiredTypeMetadataAccessFunction(IRGenModule &IGM,
NominalTypeDecl *typeDecl) {
// This needs to be kept in sync with getTypeMetadataStrategy.
if (isa<ProtocolDecl>(typeDecl))
return false;
switch (getDeclLinkage(typeDecl)) {
case FormalLinkage::PublicUnique:
case FormalLinkage::HiddenUnique:
case FormalLinkage::Private:
return true;
case FormalLinkage::PublicNonUnique:
case FormalLinkage::HiddenNonUnique:
return false;
}
llvm_unreachable("bad formal linkage");
}
/// Return the standard access strategy for getting a non-dependent
/// type metadata object.
MetadataAccessStrategy
irgen::getTypeMetadataAccessStrategy(IRGenModule &IGM, CanType type) {
// We should not be emitting accessors for partially-substituted
// generic types.
assert(!type->hasArchetype());
// Non-generic structs, enums, and classes are special cases.
//
// Note that while protocol types don't have a metadata pattern,
// we still require an accessor since we actually want to get
// the metadata for the existential type.
//
// This needs to kept in sync with hasRequiredTypeMetadataAccessPattern.
auto nominal = type->getAnyNominal();
if (nominal && !isa<ProtocolDecl>(nominal)) {
// Metadata accessors for fully-substituted generic types are
// emitted with shared linkage.
if (nominal->isGenericContext() && !nominal->isObjC()) {
if (type->isSpecialized())
return MetadataAccessStrategy::NonUniqueAccessor;
assert(type->hasUnboundGenericType());
}
// If the type doesn't guarantee that it has an access function,
// we might have to use a non-unique accessor.
// Everything else requires accessors.
switch (getDeclLinkage(nominal)) {
case FormalLinkage::PublicUnique:
return MetadataAccessStrategy::PublicUniqueAccessor;
case FormalLinkage::HiddenUnique:
return MetadataAccessStrategy::HiddenUniqueAccessor;
case FormalLinkage::Private:
return MetadataAccessStrategy::PrivateAccessor;
case FormalLinkage::PublicNonUnique:
case FormalLinkage::HiddenNonUnique:
return MetadataAccessStrategy::NonUniqueAccessor;
}
llvm_unreachable("bad formal linkage");
}
// Everything else requires a shared accessor function.
return MetadataAccessStrategy::NonUniqueAccessor;
}
/// Emit a string encoding the labels in the given tuple type.
static llvm::Constant *getTupleLabelsString(IRGenModule &IGM,
CanTupleType type) {
bool hasLabels = false;
llvm::SmallString<128> buffer;
for (auto &elt : type->getElements()) {
if (elt.hasName()) {
hasLabels = true;
buffer.append(elt.getName().str());
}
// Each label is space-terminated.
buffer += ' ';
}
// If there are no labels, use a null pointer.
if (!hasLabels) {
return llvm::ConstantPointerNull::get(IGM.Int8PtrTy);
}
// Otherwise, create a new string literal.
// This method implicitly adds a null terminator.
return IGM.getAddrOfGlobalString(buffer);
}
namespace {
/// A visitor class for emitting a reference to a metatype object.
/// This implements a "raw" access, useful for implementing cache
/// functions or for implementing dependent accesses.
///
/// If the access requires runtime initialization, that initialization
/// must be dependency-ordered-before any load that carries a dependency
/// from the resulting metadata pointer.
class EmitTypeMetadataRef
: public CanTypeVisitor<EmitTypeMetadataRef, llvm::Value *> {
private:
IRGenFunction &IGF;
public:
EmitTypeMetadataRef(IRGenFunction &IGF) : IGF(IGF) {}
#define TREAT_AS_OPAQUE(KIND) \
llvm::Value *visit##KIND##Type(KIND##Type *type) { \
return visitOpaqueType(CanType(type)); \
}
TREAT_AS_OPAQUE(BuiltinInteger)
TREAT_AS_OPAQUE(BuiltinFloat)
TREAT_AS_OPAQUE(BuiltinVector)
TREAT_AS_OPAQUE(BuiltinRawPointer)
#undef TREAT_AS_OPAQUE
llvm::Value *emitDirectMetadataRef(CanType type) {
return IGF.IGM.getAddrOfTypeMetadata(type,
/*pattern*/ false);
}
/// The given type should use opaque type info. We assume that
/// the runtime always provides an entry for such a type; right
/// now, that mapping is as one of the power-of-two integer types.
llvm::Value *visitOpaqueType(CanType type) {
auto &opaqueTI = cast<FixedTypeInfo>(IGF.IGM.getTypeInfoForLowered(type));
unsigned numBits = opaqueTI.getFixedSize().getValueInBits();
if (!llvm::isPowerOf2_32(numBits))
numBits = llvm::NextPowerOf2(numBits);
auto intTy = BuiltinIntegerType::get(numBits, IGF.IGM.Context);
return emitDirectMetadataRef(CanType(intTy));
}
llvm::Value *visitBuiltinNativeObjectType(CanBuiltinNativeObjectType type) {
return emitDirectMetadataRef(type);
}
llvm::Value *visitBuiltinBridgeObjectType(CanBuiltinBridgeObjectType type) {
return emitDirectMetadataRef(type);
}
llvm::Value *visitBuiltinUnknownObjectType(CanBuiltinUnknownObjectType type) {
return emitDirectMetadataRef(type);
}
llvm::Value *visitBuiltinUnsafeValueBufferType(
CanBuiltinUnsafeValueBufferType type) {
return emitDirectMetadataRef(type);
}
llvm::Value *visitNominalType(CanNominalType type) {
assert(!type->isExistentialType());
return emitNominalMetadataRef(IGF, type->getDecl(), type);
}
llvm::Value *visitBoundGenericType(CanBoundGenericType type) {
assert(!type->isExistentialType());
return emitNominalMetadataRef(IGF, type->getDecl(), type);
}
llvm::Value *visitTupleType(CanTupleType type) {
if (auto cached = tryGetLocal(type))
return cached;
// I think the sanest thing to do here is drop labels, but maybe
// that's not correct. If so, that's really unfortunate in a
// lot of ways.
// Er, varargs bit? Should that go in?
switch (type->getNumElements()) {
case 0: {// Special case the empty tuple, just use the global descriptor.
llvm::Constant *fullMetadata = IGF.IGM.getEmptyTupleMetadata();
llvm::Constant *indices[] = {
llvm::ConstantInt::get(IGF.IGM.Int32Ty, 0),
llvm::ConstantInt::get(IGF.IGM.Int32Ty, 1)
};
return llvm::ConstantExpr::getInBoundsGetElementPtr(
/*Ty=*/nullptr, fullMetadata, indices);
}
case 1:
// For metadata purposes, we consider a singleton tuple to be
// isomorphic to its element type.
return IGF.emitTypeMetadataRef(type.getElementType(0));
case 2: {
// Find the metadata pointer for this element.
auto elt0Metadata = IGF.emitTypeMetadataRef(type.getElementType(0));
auto elt1Metadata = IGF.emitTypeMetadataRef(type.getElementType(1));
llvm::Value *args[] = {
elt0Metadata, elt1Metadata,
getTupleLabelsString(IGF.IGM, type),
llvm::ConstantPointerNull::get(IGF.IGM.WitnessTablePtrTy) // proposed
};
auto call = IGF.Builder.CreateCall(IGF.IGM.getGetTupleMetadata2Fn(),
args);
call->setDoesNotThrow();
return setLocal(CanType(type), call);
}
case 3: {
// Find the metadata pointer for this element.
auto elt0Metadata = IGF.emitTypeMetadataRef(type.getElementType(0));
auto elt1Metadata = IGF.emitTypeMetadataRef(type.getElementType(1));
auto elt2Metadata = IGF.emitTypeMetadataRef(type.getElementType(2));
llvm::Value *args[] = {
elt0Metadata, elt1Metadata, elt2Metadata,
getTupleLabelsString(IGF.IGM, type),
llvm::ConstantPointerNull::get(IGF.IGM.WitnessTablePtrTy) // proposed
};
auto call = IGF.Builder.CreateCall(IGF.IGM.getGetTupleMetadata3Fn(),
args);
call->setDoesNotThrow();
return setLocal(CanType(type), call);
}
default:
// TODO: use a caching entrypoint (with all information
// out-of-line) for non-dependent tuples.
llvm::Value *pointerToFirst = nullptr; // appease -Wuninitialized
auto elements = type.getElementTypes();
auto arrayTy = llvm::ArrayType::get(IGF.IGM.TypeMetadataPtrTy,
elements.size());
Address buffer = IGF.createAlloca(arrayTy,IGF.IGM.getPointerAlignment(),
"tuple-elements");
IGF.Builder.CreateLifetimeStart(buffer,
IGF.IGM.getPointerSize() * elements.size());
for (unsigned i = 0, e = elements.size(); i != e; ++i) {
// Find the metadata pointer for this element.
llvm::Value *eltMetadata = IGF.emitTypeMetadataRef(elements[i]);
// GEP to the appropriate element and store.
Address eltPtr = IGF.Builder.CreateStructGEP(buffer, i,
IGF.IGM.getPointerSize());
IGF.Builder.CreateStore(eltMetadata, eltPtr);
// Remember the GEP to the first element.
if (i == 0) pointerToFirst = eltPtr.getAddress();
}
llvm::Value *args[] = {
llvm::ConstantInt::get(IGF.IGM.SizeTy, elements.size()),
pointerToFirst,
getTupleLabelsString(IGF.IGM, type),
llvm::ConstantPointerNull::get(IGF.IGM.WitnessTablePtrTy) // proposed
};
auto call = IGF.Builder.CreateCall(IGF.IGM.getGetTupleMetadataFn(),
args);
call->setDoesNotThrow();
IGF.Builder.CreateLifetimeEnd(buffer,
IGF.IGM.getPointerSize() * elements.size());
return setLocal(type, call);
}
}
llvm::Value *visitGenericFunctionType(CanGenericFunctionType type) {
IGF.unimplemented(SourceLoc(),
"metadata ref for generic function type");
return llvm::UndefValue::get(IGF.IGM.TypeMetadataPtrTy);
}
llvm::Value *extractAndMarkResultType(CanFunctionType type) {
// If the function type throws, set the lower bit of the return type
// address, so that we can carry this information over to the function
// type metadata.
auto metadata = IGF.emitTypeMetadataRef(type->getResult()->
getCanonicalType());
return metadata;
}
llvm::Value *extractAndMarkInOut(CanType type) {
// If the type is inout, get the metadata for its inner object type
// instead, and then set the lowest bit to help the runtime unique
// the metadata type for this function.
if (auto inoutType = dyn_cast<InOutType>(type)) {
auto metadata = IGF.emitTypeMetadataRef(inoutType.getObjectType());
auto metadataInt = IGF.Builder.CreatePtrToInt(metadata, IGF.IGM.SizeTy);
auto inoutFlag = llvm::ConstantInt::get(IGF.IGM.SizeTy, 1);
auto marked = IGF.Builder.CreateOr(metadataInt, inoutFlag);
return IGF.Builder.CreateIntToPtr(marked, IGF.IGM.Int8PtrTy);
}
auto metadata = IGF.emitTypeMetadataRef(type);
return IGF.Builder.CreateBitCast(metadata, IGF.IGM.Int8PtrTy);
}
llvm::Value *visitFunctionType(CanFunctionType type) {
if (auto metatype = tryGetLocal(type))
return metatype;
auto resultMetadata = extractAndMarkResultType(type);
CanTupleType inputTuple = dyn_cast<TupleType>(type.getInput());
size_t numArguments = 1;
if (inputTuple && !inputTuple->isMaterializable())
numArguments = inputTuple->getNumElements();
// Map the convention to a runtime metadata value.
FunctionMetadataConvention metadataConvention;
switch (type->getRepresentation()) {
case FunctionTypeRepresentation::Swift:
metadataConvention = FunctionMetadataConvention::Swift;
break;
case FunctionTypeRepresentation::Thin:
metadataConvention = FunctionMetadataConvention::Thin;
break;
case FunctionTypeRepresentation::Block:
metadataConvention = FunctionMetadataConvention::Block;
break;
case FunctionTypeRepresentation::CFunctionPointer:
metadataConvention = FunctionMetadataConvention::CFunctionPointer;
break;
}
auto flagsVal = FunctionTypeFlags()
.withNumArguments(numArguments)
.withConvention(metadataConvention)
.withThrows(type->throws());
auto flags = llvm::ConstantInt::get(IGF.IGM.SizeTy,
flagsVal.getIntValue());
switch (numArguments) {
case 1: {
auto arg0 = (inputTuple && !inputTuple->isMaterializable()) ?
extractAndMarkInOut(inputTuple.getElementType(0))
: extractAndMarkInOut(type.getInput());
auto call = IGF.Builder.CreateCall(
IGF.IGM.getGetFunctionMetadata1Fn(),
{flags, arg0, resultMetadata});
call->setDoesNotThrow();
return setLocal(CanType(type), call);
}
case 2: {
auto arg0 = extractAndMarkInOut(inputTuple.getElementType(0));
auto arg1 = extractAndMarkInOut(inputTuple.getElementType(1));
auto call = IGF.Builder.CreateCall(
IGF.IGM.getGetFunctionMetadata2Fn(),
{flags, arg0, arg1, resultMetadata});
call->setDoesNotThrow();
return setLocal(CanType(type), call);
}
case 3: {
auto arg0 = extractAndMarkInOut(inputTuple.getElementType(0));
auto arg1 = extractAndMarkInOut(inputTuple.getElementType(1));
auto arg2 = extractAndMarkInOut(inputTuple.getElementType(2));
auto call = IGF.Builder.CreateCall(
IGF.IGM.getGetFunctionMetadata3Fn(),
{flags, arg0, arg1, arg2,
resultMetadata});
call->setDoesNotThrow();
return setLocal(CanType(type), call);
}
default:
auto arguments = inputTuple.getElementTypes();
auto arrayTy = llvm::ArrayType::get(IGF.IGM.Int8PtrTy,
arguments.size() + 2);
Address buffer = IGF.createAlloca(arrayTy,
IGF.IGM.getPointerAlignment(),
"function-arguments");
IGF.Builder.CreateLifetimeStart(buffer,
IGF.IGM.getPointerSize() * arguments.size());
Address pointerToFirstArg = IGF.Builder.CreateStructGEP(buffer, 0,
Size(0));
Address flagsPtr = IGF.Builder.CreateBitCast(pointerToFirstArg,
IGF.IGM.SizeTy->getPointerTo());
IGF.Builder.CreateStore(flags, flagsPtr);
for (size_t i = 0; i < arguments.size(); ++i) {
auto argMetadata = extractAndMarkInOut(
inputTuple.getElementType(i));
Address argPtr = IGF.Builder.CreateStructGEP(buffer, i + 1,
IGF.IGM.getPointerSize());
IGF.Builder.CreateStore(argMetadata, argPtr);
}
Address resultPtr = IGF.Builder.CreateStructGEP(buffer,
arguments.size() + 1,
IGF.IGM.getPointerSize());
resultPtr = IGF.Builder.CreateBitCast(resultPtr,
IGF.IGM.TypeMetadataPtrTy->getPointerTo());
IGF.Builder.CreateStore(resultMetadata, resultPtr);
auto call = IGF.Builder.CreateCall(IGF.IGM.getGetFunctionMetadataFn(),
pointerToFirstArg.getAddress());
call->setDoesNotThrow();
IGF.Builder.CreateLifetimeEnd(buffer,
IGF.IGM.getPointerSize() * arguments.size());
return setLocal(type, call);
}
}
llvm::Value *visitAnyMetatypeType(CanAnyMetatypeType type) {
// FIXME: We shouldn't accept a lowered metatype here, but we need to
// represent Optional<@objc_metatype T.Type> as an AST type for ABI
// reasons.
// assert(!type->hasRepresentation()
// && "should not be asking for a representation-specific metatype "
// "metadata");
if (auto metatype = tryGetLocal(type))
return metatype;
auto instMetadata = IGF.emitTypeMetadataRef(type.getInstanceType());
auto fn = isa<MetatypeType>(type)
? IGF.IGM.getGetMetatypeMetadataFn()
: IGF.IGM.getGetExistentialMetatypeMetadataFn();
auto call = IGF.Builder.CreateCall(fn, instMetadata);
call->setDoesNotThrow();
return setLocal(type, call);
}
llvm::Value *visitModuleType(CanModuleType type) {
IGF.unimplemented(SourceLoc(), "metadata ref for module type");
return llvm::UndefValue::get(IGF.IGM.TypeMetadataPtrTy);
}
llvm::Value *visitDynamicSelfType(CanDynamicSelfType type) {
return IGF.getLocalSelfMetadata();
}
llvm::Value *emitExistentialTypeMetadata(CanType type) {
SmallVector<ProtocolDecl*, 2> protocols;
type.getAnyExistentialTypeProtocols(protocols);
// Collect references to the protocol descriptors.
auto descriptorArrayTy
= llvm::ArrayType::get(IGF.IGM.ProtocolDescriptorPtrTy,
protocols.size());
Address descriptorArray = IGF.createAlloca(descriptorArrayTy,
IGF.IGM.getPointerAlignment(),
"protocols");
IGF.Builder.CreateLifetimeStart(descriptorArray,
IGF.IGM.getPointerSize() * protocols.size());
descriptorArray = IGF.Builder.CreateBitCast(descriptorArray,
IGF.IGM.ProtocolDescriptorPtrTy->getPointerTo());
unsigned index = 0;
for (auto *p : protocols) {
llvm::Value *ref = emitProtocolDescriptorRef(IGF, p);
Address slot = IGF.Builder.CreateConstArrayGEP(descriptorArray,
index, IGF.IGM.getPointerSize());
IGF.Builder.CreateStore(ref, slot);
++index;
}
auto call = IGF.Builder.CreateCall(IGF.IGM.getGetExistentialMetadataFn(),
{IGF.IGM.getSize(Size(protocols.size())),
descriptorArray.getAddress()});
call->setDoesNotThrow();
IGF.Builder.CreateLifetimeEnd(descriptorArray,
IGF.IGM.getPointerSize() * protocols.size());
return setLocal(type, call);
}
llvm::Value *visitProtocolType(CanProtocolType type) {
return emitExistentialTypeMetadata(type);
}
llvm::Value *visitProtocolCompositionType(CanProtocolCompositionType type) {
return emitExistentialTypeMetadata(type);
}
llvm::Value *visitReferenceStorageType(CanReferenceStorageType type) {
llvm_unreachable("reference storage type should have been converted by "
"SILGen");
}
llvm::Value *visitSILFunctionType(CanSILFunctionType type) {
llvm_unreachable("should not be asking for metadata of a lowered SIL "
"function type--SILGen should have used the AST type");
}
llvm::Value *visitArchetypeType(CanArchetypeType type) {
return emitArchetypeTypeMetadataRef(IGF, type);
}
llvm::Value *visitGenericTypeParamType(CanGenericTypeParamType type) {
llvm_unreachable("dependent type should have been substituted by Sema or SILGen");
}
llvm::Value *visitDependentMemberType(CanDependentMemberType type) {
llvm_unreachable("dependent type should have been substituted by Sema or SILGen");