forked from llvm/llvm-project
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathMicrosoftCXXABI.cpp
4474 lines (3866 loc) · 181 KB
/
MicrosoftCXXABI.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
//===--- MicrosoftCXXABI.cpp - Emit LLVM Code from ASTs for a Module ------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This provides C++ code generation targeting the Microsoft Visual C++ ABI.
// The class in this file generates structures that follow the Microsoft
// Visual C++ ABI, which is actually not very well documented at all outside
// of Microsoft.
//
//===----------------------------------------------------------------------===//
#include "CGCXXABI.h"
#include "CGCleanup.h"
#include "CGVTables.h"
#include "CodeGenModule.h"
#include "CodeGenTypes.h"
#include "TargetInfo.h"
#include "clang/AST/Attr.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/VTableBuilder.h"
#include "clang/CodeGen/ConstantInitBuilder.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/IR/Intrinsics.h"
using namespace clang;
using namespace CodeGen;
namespace {
/// Holds all the vbtable globals for a given class.
struct VBTableGlobals {
const VPtrInfoVector *VBTables;
SmallVector<llvm::GlobalVariable *, 2> Globals;
};
class MicrosoftCXXABI : public CGCXXABI {
public:
MicrosoftCXXABI(CodeGenModule &CGM)
: CGCXXABI(CGM), BaseClassDescriptorType(nullptr),
ClassHierarchyDescriptorType(nullptr),
CompleteObjectLocatorType(nullptr), CatchableTypeType(nullptr),
ThrowInfoType(nullptr) {}
bool HasThisReturn(GlobalDecl GD) const override;
bool hasMostDerivedReturn(GlobalDecl GD) const override;
bool classifyReturnType(CGFunctionInfo &FI) const override;
RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const override;
bool isSRetParameterAfterThis() const override { return true; }
bool isThisCompleteObject(GlobalDecl GD) const override {
// The Microsoft ABI doesn't use separate complete-object vs.
// base-object variants of constructors, but it does of destructors.
if (isa<CXXDestructorDecl>(GD.getDecl())) {
switch (GD.getDtorType()) {
case Dtor_Complete:
case Dtor_Deleting:
return true;
case Dtor_Base:
return false;
case Dtor_Comdat: llvm_unreachable("emitting dtor comdat as function?");
}
llvm_unreachable("bad dtor kind");
}
// No other kinds.
return false;
}
size_t getSrcArgforCopyCtor(const CXXConstructorDecl *CD,
FunctionArgList &Args) const override {
assert(Args.size() >= 2 &&
"expected the arglist to have at least two args!");
// The 'most_derived' parameter goes second if the ctor is variadic and
// has v-bases.
if (CD->getParent()->getNumVBases() > 0 &&
CD->getType()->castAs<FunctionProtoType>()->isVariadic())
return 2;
return 1;
}
std::vector<CharUnits> getVBPtrOffsets(const CXXRecordDecl *RD) override {
std::vector<CharUnits> VBPtrOffsets;
const ASTContext &Context = getContext();
const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
for (const std::unique_ptr<VPtrInfo> &VBT : *VBGlobals.VBTables) {
const ASTRecordLayout &SubobjectLayout =
Context.getASTRecordLayout(VBT->IntroducingObject);
CharUnits Offs = VBT->NonVirtualOffset;
Offs += SubobjectLayout.getVBPtrOffset();
if (VBT->getVBaseWithVPtr())
Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
VBPtrOffsets.push_back(Offs);
}
llvm::array_pod_sort(VBPtrOffsets.begin(), VBPtrOffsets.end());
return VBPtrOffsets;
}
StringRef GetPureVirtualCallName() override { return "_purecall"; }
StringRef GetDeletedVirtualCallName() override { return "_purecall"; }
void emitVirtualObjectDelete(CodeGenFunction &CGF, const CXXDeleteExpr *DE,
Address Ptr, QualType ElementType,
const CXXDestructorDecl *Dtor) override;
void emitRethrow(CodeGenFunction &CGF, bool isNoReturn) override;
void emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) override;
void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) override;
llvm::GlobalVariable *getMSCompleteObjectLocator(const CXXRecordDecl *RD,
const VPtrInfo &Info);
llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
CatchTypeInfo
getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) override;
/// MSVC needs an extra flag to indicate a catchall.
CatchTypeInfo getCatchAllTypeInfo() override {
// For -EHa catch(...) must handle HW exception
// Adjective = HT_IsStdDotDot (0x40), only catch C++ exceptions
if (getContext().getLangOpts().EHAsynch)
return CatchTypeInfo{nullptr, 0};
else
return CatchTypeInfo{nullptr, 0x40};
}
bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
void EmitBadTypeidCall(CodeGenFunction &CGF) override;
llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
Address ThisPtr,
llvm::Type *StdTypeInfoPtrTy) override;
bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
QualType SrcRecordTy) override;
llvm::Value *EmitDynamicCastCall(CodeGenFunction &CGF, Address Value,
QualType SrcRecordTy, QualType DestTy,
QualType DestRecordTy,
llvm::BasicBlock *CastEnd) override;
llvm::Value *EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
QualType SrcRecordTy,
QualType DestTy) override;
bool EmitBadCastCall(CodeGenFunction &CGF) override;
bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const override {
return false;
}
llvm::Value *
GetVirtualBaseClassOffset(CodeGenFunction &CGF, Address This,
const CXXRecordDecl *ClassDecl,
const CXXRecordDecl *BaseClassDecl) override;
llvm::BasicBlock *
EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
const CXXRecordDecl *RD) override;
llvm::BasicBlock *
EmitDtorCompleteObjectHandler(CodeGenFunction &CGF);
void initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
const CXXRecordDecl *RD) override;
void EmitCXXConstructors(const CXXConstructorDecl *D) override;
// Background on MSVC destructors
// ==============================
//
// Both Itanium and MSVC ABIs have destructor variants. The variant names
// roughly correspond in the following way:
// Itanium Microsoft
// Base -> no name, just ~Class
// Complete -> vbase destructor
// Deleting -> scalar deleting destructor
// vector deleting destructor
//
// The base and complete destructors are the same as in Itanium, although the
// complete destructor does not accept a VTT parameter when there are virtual
// bases. A separate mechanism involving vtordisps is used to ensure that
// virtual methods of destroyed subobjects are not called.
//
// The deleting destructors accept an i32 bitfield as a second parameter. Bit
// 1 indicates if the memory should be deleted. Bit 2 indicates if the this
// pointer points to an array. The scalar deleting destructor assumes that
// bit 2 is zero, and therefore does not contain a loop.
//
// For virtual destructors, only one entry is reserved in the vftable, and it
// always points to the vector deleting destructor. The vector deleting
// destructor is the most general, so it can be used to destroy objects in
// place, delete single heap objects, or delete arrays.
//
// A TU defining a non-inline destructor is only guaranteed to emit a base
// destructor, and all of the other variants are emitted on an as-needed basis
// in COMDATs. Because a non-base destructor can be emitted in a TU that
// lacks a definition for the destructor, non-base destructors must always
// delegate to or alias the base destructor.
AddedStructorArgCounts
buildStructorSignature(GlobalDecl GD,
SmallVectorImpl<CanQualType> &ArgTys) override;
/// Non-base dtors should be emitted as delegating thunks in this ABI.
bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
CXXDtorType DT) const override {
return DT != Dtor_Base;
}
void setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
const CXXDestructorDecl *Dtor,
CXXDtorType DT) const override;
llvm::GlobalValue::LinkageTypes
getCXXDestructorLinkage(GVALinkage Linkage, const CXXDestructorDecl *Dtor,
CXXDtorType DT) const override;
void EmitCXXDestructors(const CXXDestructorDecl *D) override;
const CXXRecordDecl *
getThisArgumentTypeForMethod(const CXXMethodDecl *MD) override {
if (MD->isVirtual() && !isa<CXXDestructorDecl>(MD)) {
MethodVFTableLocation ML =
CGM.getMicrosoftVTableContext().getMethodVFTableLocation(MD);
// The vbases might be ordered differently in the final overrider object
// and the complete object, so the "this" argument may sometimes point to
// memory that has no particular type (e.g. past the complete object).
// In this case, we just use a generic pointer type.
// FIXME: might want to have a more precise type in the non-virtual
// multiple inheritance case.
if (ML.VBase || !ML.VFPtrOffset.isZero())
return nullptr;
}
return MD->getParent();
}
Address
adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
Address This,
bool VirtualCall) override;
void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
FunctionArgList &Params) override;
void EmitInstanceFunctionProlog(CodeGenFunction &CGF) override;
AddedStructorArgs getImplicitConstructorArgs(CodeGenFunction &CGF,
const CXXConstructorDecl *D,
CXXCtorType Type,
bool ForVirtualBase,
bool Delegating) override;
llvm::Value *getCXXDestructorImplicitParam(CodeGenFunction &CGF,
const CXXDestructorDecl *DD,
CXXDtorType Type,
bool ForVirtualBase,
bool Delegating) override;
void EmitDestructorCall(CodeGenFunction &CGF, const CXXDestructorDecl *DD,
CXXDtorType Type, bool ForVirtualBase,
bool Delegating, Address This,
QualType ThisTy) override;
void emitVTableTypeMetadata(const VPtrInfo &Info, const CXXRecordDecl *RD,
llvm::GlobalVariable *VTable);
void emitVTableDefinitions(CodeGenVTables &CGVT,
const CXXRecordDecl *RD) override;
bool isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
CodeGenFunction::VPtr Vptr) override;
/// Don't initialize vptrs if dynamic class
/// is marked with with the 'novtable' attribute.
bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
return !VTableClass->hasAttr<MSNoVTableAttr>();
}
llvm::Constant *
getVTableAddressPoint(BaseSubobject Base,
const CXXRecordDecl *VTableClass) override;
llvm::Value *getVTableAddressPointInStructor(
CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
BaseSubobject Base, const CXXRecordDecl *NearestVBase) override;
llvm::Constant *
getVTableAddressPointForConstExpr(BaseSubobject Base,
const CXXRecordDecl *VTableClass) override;
llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
CharUnits VPtrOffset) override;
CGCallee getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD,
Address This, llvm::Type *Ty,
SourceLocation Loc) override;
llvm::Value *EmitVirtualDestructorCall(CodeGenFunction &CGF,
const CXXDestructorDecl *Dtor,
CXXDtorType DtorType, Address This,
DeleteOrMemberCallExpr E) override;
void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF, GlobalDecl GD,
CallArgList &CallArgs) override {
assert(GD.getDtorType() == Dtor_Deleting &&
"Only deleting destructor thunks are available in this ABI");
CallArgs.add(RValue::get(getStructorImplicitParamValue(CGF)),
getContext().IntTy);
}
void emitVirtualInheritanceTables(const CXXRecordDecl *RD) override;
llvm::GlobalVariable *
getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
llvm::GlobalVariable::LinkageTypes Linkage);
llvm::GlobalVariable *
getAddrOfVirtualDisplacementMap(const CXXRecordDecl *SrcRD,
const CXXRecordDecl *DstRD) {
SmallString<256> OutName;
llvm::raw_svector_ostream Out(OutName);
getMangleContext().mangleCXXVirtualDisplacementMap(SrcRD, DstRD, Out);
StringRef MangledName = OutName.str();
if (auto *VDispMap = CGM.getModule().getNamedGlobal(MangledName))
return VDispMap;
MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
unsigned NumEntries = 1 + SrcRD->getNumVBases();
SmallVector<llvm::Constant *, 4> Map(NumEntries,
llvm::UndefValue::get(CGM.IntTy));
Map[0] = llvm::ConstantInt::get(CGM.IntTy, 0);
bool AnyDifferent = false;
for (const auto &I : SrcRD->vbases()) {
const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
if (!DstRD->isVirtuallyDerivedFrom(VBase))
continue;
unsigned SrcVBIndex = VTContext.getVBTableIndex(SrcRD, VBase);
unsigned DstVBIndex = VTContext.getVBTableIndex(DstRD, VBase);
Map[SrcVBIndex] = llvm::ConstantInt::get(CGM.IntTy, DstVBIndex * 4);
AnyDifferent |= SrcVBIndex != DstVBIndex;
}
// This map would be useless, don't use it.
if (!AnyDifferent)
return nullptr;
llvm::ArrayType *VDispMapTy = llvm::ArrayType::get(CGM.IntTy, Map.size());
llvm::Constant *Init = llvm::ConstantArray::get(VDispMapTy, Map);
llvm::GlobalValue::LinkageTypes Linkage =
SrcRD->isExternallyVisible() && DstRD->isExternallyVisible()
? llvm::GlobalValue::LinkOnceODRLinkage
: llvm::GlobalValue::InternalLinkage;
auto *VDispMap = new llvm::GlobalVariable(
CGM.getModule(), VDispMapTy, /*isConstant=*/true, Linkage,
/*Initializer=*/Init, MangledName);
return VDispMap;
}
void emitVBTableDefinition(const VPtrInfo &VBT, const CXXRecordDecl *RD,
llvm::GlobalVariable *GV) const;
void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
GlobalDecl GD, bool ReturnAdjustment) override {
GVALinkage Linkage =
getContext().GetGVALinkageForFunction(cast<FunctionDecl>(GD.getDecl()));
if (Linkage == GVA_Internal)
Thunk->setLinkage(llvm::GlobalValue::InternalLinkage);
else if (ReturnAdjustment)
Thunk->setLinkage(llvm::GlobalValue::WeakODRLinkage);
else
Thunk->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
}
bool exportThunk() override { return false; }
llvm::Value *performThisAdjustment(CodeGenFunction &CGF, Address This,
const ThisAdjustment &TA) override;
llvm::Value *performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
const ReturnAdjustment &RA) override;
void EmitThreadLocalInitFuncs(
CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
ArrayRef<llvm::Function *> CXXThreadLocalInits,
ArrayRef<const VarDecl *> CXXThreadLocalInitVars) override;
bool usesThreadWrapperFunction(const VarDecl *VD) const override {
return getContext().getLangOpts().isCompatibleWithMSVC(
LangOptions::MSVC2019_5) &&
(!isEmittedWithConstantInitializer(VD) || mayNeedDestruction(VD));
}
LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF, const VarDecl *VD,
QualType LValType) override;
void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
llvm::GlobalVariable *DeclPtr,
bool PerformInit) override;
void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
llvm::FunctionCallee Dtor,
llvm::Constant *Addr) override;
// ==== Notes on array cookies =========
//
// MSVC seems to only use cookies when the class has a destructor; a
// two-argument usual array deallocation function isn't sufficient.
//
// For example, this code prints "100" and "1":
// struct A {
// char x;
// void *operator new[](size_t sz) {
// printf("%u\n", sz);
// return malloc(sz);
// }
// void operator delete[](void *p, size_t sz) {
// printf("%u\n", sz);
// free(p);
// }
// };
// int main() {
// A *p = new A[100];
// delete[] p;
// }
// Whereas it prints "104" and "104" if you give A a destructor.
bool requiresArrayCookie(const CXXDeleteExpr *expr,
QualType elementType) override;
bool requiresArrayCookie(const CXXNewExpr *expr) override;
CharUnits getArrayCookieSizeImpl(QualType type) override;
Address InitializeArrayCookie(CodeGenFunction &CGF,
Address NewPtr,
llvm::Value *NumElements,
const CXXNewExpr *expr,
QualType ElementType) override;
llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
Address allocPtr,
CharUnits cookieSize) override;
friend struct MSRTTIBuilder;
bool isImageRelative() const {
return CGM.getTarget().getPointerWidth(/*AddrSpace=*/0) == 64;
}
// 5 routines for constructing the llvm types for MS RTTI structs.
llvm::StructType *getTypeDescriptorType(StringRef TypeInfoString) {
llvm::SmallString<32> TDTypeName("rtti.TypeDescriptor");
TDTypeName += llvm::utostr(TypeInfoString.size());
llvm::StructType *&TypeDescriptorType =
TypeDescriptorTypeMap[TypeInfoString.size()];
if (TypeDescriptorType)
return TypeDescriptorType;
llvm::Type *FieldTypes[] = {
CGM.Int8PtrPtrTy,
CGM.Int8PtrTy,
llvm::ArrayType::get(CGM.Int8Ty, TypeInfoString.size() + 1)};
TypeDescriptorType =
llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, TDTypeName);
return TypeDescriptorType;
}
llvm::Type *getImageRelativeType(llvm::Type *PtrType) {
if (!isImageRelative())
return PtrType;
return CGM.IntTy;
}
llvm::StructType *getBaseClassDescriptorType() {
if (BaseClassDescriptorType)
return BaseClassDescriptorType;
llvm::Type *FieldTypes[] = {
getImageRelativeType(CGM.Int8PtrTy),
CGM.IntTy,
CGM.IntTy,
CGM.IntTy,
CGM.IntTy,
CGM.IntTy,
getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
};
BaseClassDescriptorType = llvm::StructType::create(
CGM.getLLVMContext(), FieldTypes, "rtti.BaseClassDescriptor");
return BaseClassDescriptorType;
}
llvm::StructType *getClassHierarchyDescriptorType() {
if (ClassHierarchyDescriptorType)
return ClassHierarchyDescriptorType;
// Forward-declare RTTIClassHierarchyDescriptor to break a cycle.
ClassHierarchyDescriptorType = llvm::StructType::create(
CGM.getLLVMContext(), "rtti.ClassHierarchyDescriptor");
llvm::Type *FieldTypes[] = {
CGM.IntTy,
CGM.IntTy,
CGM.IntTy,
getImageRelativeType(
getBaseClassDescriptorType()->getPointerTo()->getPointerTo()),
};
ClassHierarchyDescriptorType->setBody(FieldTypes);
return ClassHierarchyDescriptorType;
}
llvm::StructType *getCompleteObjectLocatorType() {
if (CompleteObjectLocatorType)
return CompleteObjectLocatorType;
CompleteObjectLocatorType = llvm::StructType::create(
CGM.getLLVMContext(), "rtti.CompleteObjectLocator");
llvm::Type *FieldTypes[] = {
CGM.IntTy,
CGM.IntTy,
CGM.IntTy,
getImageRelativeType(CGM.Int8PtrTy),
getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
getImageRelativeType(CompleteObjectLocatorType),
};
llvm::ArrayRef<llvm::Type *> FieldTypesRef(FieldTypes);
if (!isImageRelative())
FieldTypesRef = FieldTypesRef.drop_back();
CompleteObjectLocatorType->setBody(FieldTypesRef);
return CompleteObjectLocatorType;
}
llvm::GlobalVariable *getImageBase() {
StringRef Name = "__ImageBase";
if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name))
return GV;
auto *GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty,
/*isConstant=*/true,
llvm::GlobalValue::ExternalLinkage,
/*Initializer=*/nullptr, Name);
CGM.setDSOLocal(GV);
return GV;
}
llvm::Constant *getImageRelativeConstant(llvm::Constant *PtrVal) {
if (!isImageRelative())
return PtrVal;
if (PtrVal->isNullValue())
return llvm::Constant::getNullValue(CGM.IntTy);
llvm::Constant *ImageBaseAsInt =
llvm::ConstantExpr::getPtrToInt(getImageBase(), CGM.IntPtrTy);
llvm::Constant *PtrValAsInt =
llvm::ConstantExpr::getPtrToInt(PtrVal, CGM.IntPtrTy);
llvm::Constant *Diff =
llvm::ConstantExpr::getSub(PtrValAsInt, ImageBaseAsInt,
/*HasNUW=*/true, /*HasNSW=*/true);
return llvm::ConstantExpr::getTrunc(Diff, CGM.IntTy);
}
private:
MicrosoftMangleContext &getMangleContext() {
return cast<MicrosoftMangleContext>(CodeGen::CGCXXABI::getMangleContext());
}
llvm::Constant *getZeroInt() {
return llvm::ConstantInt::get(CGM.IntTy, 0);
}
llvm::Constant *getAllOnesInt() {
return llvm::Constant::getAllOnesValue(CGM.IntTy);
}
CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) override;
void
GetNullMemberPointerFields(const MemberPointerType *MPT,
llvm::SmallVectorImpl<llvm::Constant *> &fields);
/// Shared code for virtual base adjustment. Returns the offset from
/// the vbptr to the virtual base. Optionally returns the address of the
/// vbptr itself.
llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
Address Base,
llvm::Value *VBPtrOffset,
llvm::Value *VBTableOffset,
llvm::Value **VBPtr = nullptr);
llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
Address Base,
int32_t VBPtrOffset,
int32_t VBTableOffset,
llvm::Value **VBPtr = nullptr) {
assert(VBTableOffset % 4 == 0 && "should be byte offset into table of i32s");
llvm::Value *VBPOffset = llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
*VBTOffset = llvm::ConstantInt::get(CGM.IntTy, VBTableOffset);
return GetVBaseOffsetFromVBPtr(CGF, Base, VBPOffset, VBTOffset, VBPtr);
}
std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
performBaseAdjustment(CodeGenFunction &CGF, Address Value,
QualType SrcRecordTy);
/// Performs a full virtual base adjustment. Used to dereference
/// pointers to members of virtual bases.
llvm::Value *AdjustVirtualBase(CodeGenFunction &CGF, const Expr *E,
const CXXRecordDecl *RD, Address Base,
llvm::Value *VirtualBaseAdjustmentOffset,
llvm::Value *VBPtrOffset /* optional */);
/// Emits a full member pointer with the fields common to data and
/// function member pointers.
llvm::Constant *EmitFullMemberPointer(llvm::Constant *FirstField,
bool IsMemberFunction,
const CXXRecordDecl *RD,
CharUnits NonVirtualBaseAdjustment,
unsigned VBTableIndex);
bool MemberPointerConstantIsNull(const MemberPointerType *MPT,
llvm::Constant *MP);
/// - Initialize all vbptrs of 'this' with RD as the complete type.
void EmitVBPtrStores(CodeGenFunction &CGF, const CXXRecordDecl *RD);
/// Caching wrapper around VBTableBuilder::enumerateVBTables().
const VBTableGlobals &enumerateVBTables(const CXXRecordDecl *RD);
/// Generate a thunk for calling a virtual member function MD.
llvm::Function *EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
const MethodVFTableLocation &ML);
llvm::Constant *EmitMemberDataPointer(const CXXRecordDecl *RD,
CharUnits offset);
public:
llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT) override;
bool isZeroInitializable(const MemberPointerType *MPT) override;
bool isMemberPointerConvertible(const MemberPointerType *MPT) const override {
const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
return RD->hasAttr<MSInheritanceAttr>();
}
llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT) override;
llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
CharUnits offset) override;
llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD) override;
llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT) override;
llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF,
llvm::Value *L,
llvm::Value *R,
const MemberPointerType *MPT,
bool Inequality) override;
llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
llvm::Value *MemPtr,
const MemberPointerType *MPT) override;
llvm::Value *
EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
Address Base, llvm::Value *MemPtr,
const MemberPointerType *MPT) override;
llvm::Value *EmitNonNullMemberPointerConversion(
const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
CastKind CK, CastExpr::path_const_iterator PathBegin,
CastExpr::path_const_iterator PathEnd, llvm::Value *Src,
CGBuilderTy &Builder);
llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
const CastExpr *E,
llvm::Value *Src) override;
llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
llvm::Constant *Src) override;
llvm::Constant *EmitMemberPointerConversion(
const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
CastKind CK, CastExpr::path_const_iterator PathBegin,
CastExpr::path_const_iterator PathEnd, llvm::Constant *Src);
CGCallee
EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, const Expr *E,
Address This, llvm::Value *&ThisPtrForCall,
llvm::Value *MemPtr,
const MemberPointerType *MPT) override;
void emitCXXStructor(GlobalDecl GD) override;
llvm::StructType *getCatchableTypeType() {
if (CatchableTypeType)
return CatchableTypeType;
llvm::Type *FieldTypes[] = {
CGM.IntTy, // Flags
getImageRelativeType(CGM.Int8PtrTy), // TypeDescriptor
CGM.IntTy, // NonVirtualAdjustment
CGM.IntTy, // OffsetToVBPtr
CGM.IntTy, // VBTableIndex
CGM.IntTy, // Size
getImageRelativeType(CGM.Int8PtrTy) // CopyCtor
};
CatchableTypeType = llvm::StructType::create(
CGM.getLLVMContext(), FieldTypes, "eh.CatchableType");
return CatchableTypeType;
}
llvm::StructType *getCatchableTypeArrayType(uint32_t NumEntries) {
llvm::StructType *&CatchableTypeArrayType =
CatchableTypeArrayTypeMap[NumEntries];
if (CatchableTypeArrayType)
return CatchableTypeArrayType;
llvm::SmallString<23> CTATypeName("eh.CatchableTypeArray.");
CTATypeName += llvm::utostr(NumEntries);
llvm::Type *CTType =
getImageRelativeType(getCatchableTypeType()->getPointerTo());
llvm::Type *FieldTypes[] = {
CGM.IntTy, // NumEntries
llvm::ArrayType::get(CTType, NumEntries) // CatchableTypes
};
CatchableTypeArrayType =
llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, CTATypeName);
return CatchableTypeArrayType;
}
llvm::StructType *getThrowInfoType() {
if (ThrowInfoType)
return ThrowInfoType;
llvm::Type *FieldTypes[] = {
CGM.IntTy, // Flags
getImageRelativeType(CGM.Int8PtrTy), // CleanupFn
getImageRelativeType(CGM.Int8PtrTy), // ForwardCompat
getImageRelativeType(CGM.Int8PtrTy) // CatchableTypeArray
};
ThrowInfoType = llvm::StructType::create(CGM.getLLVMContext(), FieldTypes,
"eh.ThrowInfo");
return ThrowInfoType;
}
llvm::FunctionCallee getThrowFn() {
// _CxxThrowException is passed an exception object and a ThrowInfo object
// which describes the exception.
llvm::Type *Args[] = {CGM.Int8PtrTy, getThrowInfoType()->getPointerTo()};
llvm::FunctionType *FTy =
llvm::FunctionType::get(CGM.VoidTy, Args, /*isVarArg=*/false);
llvm::FunctionCallee Throw =
CGM.CreateRuntimeFunction(FTy, "_CxxThrowException");
// _CxxThrowException is stdcall on 32-bit x86 platforms.
if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86) {
if (auto *Fn = dyn_cast<llvm::Function>(Throw.getCallee()))
Fn->setCallingConv(llvm::CallingConv::X86_StdCall);
}
return Throw;
}
llvm::Function *getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
CXXCtorType CT);
llvm::Constant *getCatchableType(QualType T,
uint32_t NVOffset = 0,
int32_t VBPtrOffset = -1,
uint32_t VBIndex = 0);
llvm::GlobalVariable *getCatchableTypeArray(QualType T);
llvm::GlobalVariable *getThrowInfo(QualType T) override;
std::pair<llvm::Value *, const CXXRecordDecl *>
LoadVTablePtr(CodeGenFunction &CGF, Address This,
const CXXRecordDecl *RD) override;
virtual bool
isPermittedToBeHomogeneousAggregate(const CXXRecordDecl *RD) const override;
private:
typedef std::pair<const CXXRecordDecl *, CharUnits> VFTableIdTy;
typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalVariable *> VTablesMapTy;
typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalValue *> VFTablesMapTy;
/// All the vftables that have been referenced.
VFTablesMapTy VFTablesMap;
VTablesMapTy VTablesMap;
/// This set holds the record decls we've deferred vtable emission for.
llvm::SmallPtrSet<const CXXRecordDecl *, 4> DeferredVFTables;
/// All the vbtables which have been referenced.
llvm::DenseMap<const CXXRecordDecl *, VBTableGlobals> VBTablesMap;
/// Info on the global variable used to guard initialization of static locals.
/// The BitIndex field is only used for externally invisible declarations.
struct GuardInfo {
GuardInfo() : Guard(nullptr), BitIndex(0) {}
llvm::GlobalVariable *Guard;
unsigned BitIndex;
};
/// Map from DeclContext to the current guard variable. We assume that the
/// AST is visited in source code order.
llvm::DenseMap<const DeclContext *, GuardInfo> GuardVariableMap;
llvm::DenseMap<const DeclContext *, GuardInfo> ThreadLocalGuardVariableMap;
llvm::DenseMap<const DeclContext *, unsigned> ThreadSafeGuardNumMap;
llvm::DenseMap<size_t, llvm::StructType *> TypeDescriptorTypeMap;
llvm::StructType *BaseClassDescriptorType;
llvm::StructType *ClassHierarchyDescriptorType;
llvm::StructType *CompleteObjectLocatorType;
llvm::DenseMap<QualType, llvm::GlobalVariable *> CatchableTypeArrays;
llvm::StructType *CatchableTypeType;
llvm::DenseMap<uint32_t, llvm::StructType *> CatchableTypeArrayTypeMap;
llvm::StructType *ThrowInfoType;
};
}
CGCXXABI::RecordArgABI
MicrosoftCXXABI::getRecordArgABI(const CXXRecordDecl *RD) const {
// Use the default C calling convention rules for things that can be passed in
// registers, i.e. non-trivially copyable records or records marked with
// [[trivial_abi]].
if (RD->canPassInRegisters())
return RAA_Default;
switch (CGM.getTarget().getTriple().getArch()) {
default:
// FIXME: Implement for other architectures.
return RAA_Indirect;
case llvm::Triple::thumb:
// Pass things indirectly for now because it is simple.
// FIXME: This is incompatible with MSVC for arguments with a dtor and no
// copy ctor.
return RAA_Indirect;
case llvm::Triple::x86: {
// If the argument has *required* alignment greater than four bytes, pass
// it indirectly. Prior to MSVC version 19.14, passing overaligned
// arguments was not supported and resulted in a compiler error. In 19.14
// and later versions, such arguments are now passed indirectly.
TypeInfo Info = getContext().getTypeInfo(RD->getTypeForDecl());
if (Info.isAlignRequired() && Info.Align > 4)
return RAA_Indirect;
// If C++ prohibits us from making a copy, construct the arguments directly
// into argument memory.
return RAA_DirectInMemory;
}
case llvm::Triple::x86_64:
case llvm::Triple::aarch64:
return RAA_Indirect;
}
llvm_unreachable("invalid enum");
}
void MicrosoftCXXABI::emitVirtualObjectDelete(CodeGenFunction &CGF,
const CXXDeleteExpr *DE,
Address Ptr,
QualType ElementType,
const CXXDestructorDecl *Dtor) {
// FIXME: Provide a source location here even though there's no
// CXXMemberCallExpr for dtor call.
bool UseGlobalDelete = DE->isGlobalDelete();
CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
llvm::Value *MDThis = EmitVirtualDestructorCall(CGF, Dtor, DtorType, Ptr, DE);
if (UseGlobalDelete)
CGF.EmitDeleteCall(DE->getOperatorDelete(), MDThis, ElementType);
}
void MicrosoftCXXABI::emitRethrow(CodeGenFunction &CGF, bool isNoReturn) {
llvm::Value *Args[] = {
llvm::ConstantPointerNull::get(CGM.Int8PtrTy),
llvm::ConstantPointerNull::get(getThrowInfoType()->getPointerTo())};
llvm::FunctionCallee Fn = getThrowFn();
if (isNoReturn)
CGF.EmitNoreturnRuntimeCallOrInvoke(Fn, Args);
else
CGF.EmitRuntimeCallOrInvoke(Fn, Args);
}
void MicrosoftCXXABI::emitBeginCatch(CodeGenFunction &CGF,
const CXXCatchStmt *S) {
// In the MS ABI, the runtime handles the copy, and the catch handler is
// responsible for destruction.
VarDecl *CatchParam = S->getExceptionDecl();
llvm::BasicBlock *CatchPadBB = CGF.Builder.GetInsertBlock();
llvm::CatchPadInst *CPI =
cast<llvm::CatchPadInst>(CatchPadBB->getFirstNonPHI());
CGF.CurrentFuncletPad = CPI;
// If this is a catch-all or the catch parameter is unnamed, we don't need to
// emit an alloca to the object.
if (!CatchParam || !CatchParam->getDeclName()) {
CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
return;
}
CodeGenFunction::AutoVarEmission var = CGF.EmitAutoVarAlloca(*CatchParam);
CPI->setArgOperand(2, var.getObjectAddress(CGF).getPointer());
CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
CGF.EmitAutoVarCleanups(var);
}
/// We need to perform a generic polymorphic operation (like a typeid
/// or a cast), which requires an object with a vfptr. Adjust the
/// address to point to an object with a vfptr.
std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
MicrosoftCXXABI::performBaseAdjustment(CodeGenFunction &CGF, Address Value,
QualType SrcRecordTy) {
Value = CGF.Builder.CreateElementBitCast(Value, CGF.Int8Ty);
const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
const ASTContext &Context = getContext();
// If the class itself has a vfptr, great. This check implicitly
// covers non-virtual base subobjects: a class with its own virtual
// functions would be a candidate to be a primary base.
if (Context.getASTRecordLayout(SrcDecl).hasExtendableVFPtr())
return std::make_tuple(Value, llvm::ConstantInt::get(CGF.Int32Ty, 0),
SrcDecl);
// Okay, one of the vbases must have a vfptr, or else this isn't
// actually a polymorphic class.
const CXXRecordDecl *PolymorphicBase = nullptr;
for (auto &Base : SrcDecl->vbases()) {
const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
if (Context.getASTRecordLayout(BaseDecl).hasExtendableVFPtr()) {
PolymorphicBase = BaseDecl;
break;
}
}
assert(PolymorphicBase && "polymorphic class has no apparent vfptr?");
llvm::Value *Offset =
GetVirtualBaseClassOffset(CGF, Value, SrcDecl, PolymorphicBase);
llvm::Value *Ptr = CGF.Builder.CreateInBoundsGEP(
Value.getElementType(), Value.getPointer(), Offset);
CharUnits VBaseAlign =
CGF.CGM.getVBaseAlignment(Value.getAlignment(), SrcDecl, PolymorphicBase);
return std::make_tuple(Address(Ptr, VBaseAlign), Offset, PolymorphicBase);
}
bool MicrosoftCXXABI::shouldTypeidBeNullChecked(bool IsDeref,
QualType SrcRecordTy) {
const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
return IsDeref &&
!getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
}
static llvm::CallBase *emitRTtypeidCall(CodeGenFunction &CGF,
llvm::Value *Argument) {
llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
llvm::FunctionType *FTy =
llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false);
llvm::Value *Args[] = {Argument};
llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(FTy, "__RTtypeid");
return CGF.EmitRuntimeCallOrInvoke(Fn, Args);
}
void MicrosoftCXXABI::EmitBadTypeidCall(CodeGenFunction &CGF) {
llvm::CallBase *Call =
emitRTtypeidCall(CGF, llvm::Constant::getNullValue(CGM.VoidPtrTy));
Call->setDoesNotReturn();
CGF.Builder.CreateUnreachable();
}
llvm::Value *MicrosoftCXXABI::EmitTypeid(CodeGenFunction &CGF,
QualType SrcRecordTy,
Address ThisPtr,
llvm::Type *StdTypeInfoPtrTy) {
std::tie(ThisPtr, std::ignore, std::ignore) =
performBaseAdjustment(CGF, ThisPtr, SrcRecordTy);
llvm::CallBase *Typeid = emitRTtypeidCall(CGF, ThisPtr.getPointer());
return CGF.Builder.CreateBitCast(Typeid, StdTypeInfoPtrTy);
}
bool MicrosoftCXXABI::shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
QualType SrcRecordTy) {
const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
return SrcIsPtr &&
!getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
}
llvm::Value *MicrosoftCXXABI::EmitDynamicCastCall(
CodeGenFunction &CGF, Address This, QualType SrcRecordTy,
QualType DestTy, QualType DestRecordTy, llvm::BasicBlock *CastEnd) {
llvm::Type *DestLTy = CGF.ConvertType(DestTy);
llvm::Value *SrcRTTI =